civil and structural works - hong kong … materials & workmanship specification issue no. 5,...

GENERAL MATERIALS AND WORKMANSHIP

SPECIFICATION

VOLUME 1

CIVIL AND STRUCTURAL WORKS

ISSUE NO. 5

JANUARY 2011

[this page not used]

General Materials & Workmanship Specification - i - January 2011 Issue No. 5 – Table of Contents

GENERAL MATERIALS AND WORKMANSHIP SPECIFICATION

TABLE OF CONTENTS

VOLUME 1 CIVIL AND STRUCTURAL WORKS Section 1 General – Civil and Structural Works

2 Temporary Works

3 Site Clearance

4 Landscaping Works

5 Fencing

6 Drainage Works

7 Earthworks

8 Geotechnical Works

9 Carriageways: Sub-base Material and Bituminous Materials

10 Concrete Carriageways

11 Miscellaneous Roadworks

12 Traffic Signs, Road Markings and Road Studs

13 Work for Electrical and Mechanical Installations

14 Water Supply Pipeworks

15 Not Used

16 Not Used

17 Piling Works

18 Formwork and Finishes to Concrete

19 Steel Reinforcement

20 Concrete and Joints in Concrete

21 Prestressing

22 Steelwork

23 Bridgeworks

24 Water Retaining Structures

VOLUME 2 ARCHITECTURAL WORKS Section 25 General – Architectural Works

26 Masonry and Blockwork

27 Waterproofing and Tanking

28 Roofing and Wall Cladding

29 Curtain Walling

General Materials & Workmanship Specification - ii - January 2011 Issue No. 5 – Table of Contents


TABLE OF CONTENTS (CONT’D)

VOLUME 2 ARCHITECTURAL WORKS (CONT’D) Section 30 Internal Cladding Systems

31 Carpentry and Joinery

32 Internal Cladding Systems

33 Linings, Sheathings, Drywall Partitions and Toilet Cubicles

34 Suspender Ceilings

35 Architectural Metalwork (Including Metal Doors and Shutters)

36 Ironmongery

37 Hard Floor Finishes

38 Flexible Floor Finishes

39 Wall Finishes

40 Painting and Decoration

41 Fire Protection and Fire Stopping Systems

42 Signage

43 Not Used

VOLUME 3 ELECTRICAL AND MECHANICAL WORKS Section 44 General – Electrical and Mechanical Works

45 Electrical Supply

46 Low Voltage Switchboards

47 Sub-Mains Electrical Distribution Equipment

48 Wiring and Cables

49 Cable Management Systems

50 Wiring Accessories and Miscellaneous Electrical Equipment

51 General Lighting Systems

52 Uninterruptible Power Supply System (UPS)

53 Motors

54 High Voltage Electrical Services

57 Earthing and Bonding System

58 Lighting Protection System

59 Electromagnetic Compatibility

60 Inspection, Testing and Commissioning - Electrical Services

General Materials & Workmanship Specification - iii - January 2011 Issue No. 5 – Table of Contents



VOLUME 3 ELECTRICAL AND MECHANICAL WORKS (CONT’D) Section 61 Air Handling units

62 Fan Coil Units

63 Fans

64 Split Type Air Conditioning Unit

65 Window Type Air Conditioning Unit

66 Air Cooling Coils

67 Dampers and Air Volume Control Devices

68 Registers, Diffusers and Grilles

69 Air Filters

70 Ductwork and Fittings

71 Water Handling Equipment

72 Pipeworks, Fittings and Valves

73 Thermal Insulation

74 Sound Attentuator

75 Noise and Vibration Control

76 Electrical Equipment and Installation

77 Automatic Controls

78 Instruments

79 Testing, Inspection and Commissioning – Mechanical Services

80 Automatic Sprinkler System

81 Hydrant and Hose Reel System

82 Gaseous Fire Extinguishing System (FM200)

83 Fire Alarm and Detection System

84 Portable Hand Equipment

85 Visual Fire Alarm

86 Exist Sign and Directional Sign

87 Pipework, Valves and Fittings

88 Pumps and Tanks

89 Automatic Sprinkler System

90 Inspection, Testing and Commissioning – Fire Services

General Materials & Workmanship Specification - iv - January 2011 Issue No. 5 – Table of Contents



VOLUME 3 ELECTRICAL AND MECHANICAL WORKS (CONT’D) Section 91 Foul Water Disposal

92 Storm Water Disposal

93 Water Supply

94 Hot Water Supply System

95 Pipework, Fittings and Valves

96 Town Gas Reticulation

97 Pumps and Tank Level Controls

98 Electrical Equipment and Installation

99 Inspection, Testing and Commissioning – Hydraulic Services

100 General Building Management System

101 Mechanical Building Management System

102 Voice and Data

103 Public Address System

104 Access Control System

105 Trunked Mobile Radio System

106 Closed Circuit Television System

107 Master Antenna Television (MATV)

108 Inspection, Testing and Commissioning – Airport Systems

109 Not Used

110 Not Used

111 Not Used

112 Not Used

113 Not Used

114 Not Used

115 Not Used

116 Not Used

117 Not Used

118 Not Used

119 Not Used

General Materials & Workmanship Specification - v - January 2011 Issue No. 5 – Table of Contents



VOLUME 4 AIRFIELD WORKS Section 120 General - Airfield Works

121 Airfield Ground Lighting System

122 Airport Lightning Warning System

123 Fixed Ground Power System

124 High Mast Lighting system

125 Pre-conditioned Air Supply Units

126 Aircraft Parking Aid System

127 Airfield Supervisory Control and Data Acquisition System

128 Aircraft Loading Bridges

129 Perimeter Fence Lighting System

130 Jet Blast Screens

General Materials & Workmanship Specification Issue No. 5, Volume 1 – Civil & Structural Works Table of Contents 1/9 January 2011

GENERAL MATERIALS AND WORKMANSHIP SPECIFICATION VOLUME 1 – CIVIL AND STRUCTURAL WORKS SECTION 1 GENERAL – CIVIL AND STRUCTURAL WORKS 1.1 Definitions and Abbreviations 1.2 Relevant Codes and Standards SECTION 2 TEMPORARY WORKS 2.1 Introduction 2.2 Design and Performance Criteria

APPENDIX A2.1 Temporary Works Design Criteria A2.1.1 Preamble A2.1.2 Ground Movement A2.1.3 Ground Water A2.1.4 Construction Method A2.1.5 Loads and Forces A2.1.6 Excavation A2.1.7 Design Life A2.1.8 Cofferdams and Temporary Retaining Walls A2.1.9 Temporary Decks and Pedestrian Bridges A2.1.10 Falsework A2.1.11 Formwork A2.1.12 Earthworks APPENDIX A2.2 Certification of the Design of Temporary Works APPENDIX A2.3 Certification of Loading, Dismantling or Removal of Temporary Works SECTION 3 SITE CLEARANCE AND DEMOLITION 3.1 General 3.2 Relevant Codes and Standards 3.3 Submissions 3.4 Workmanship 3.5 Inspection


SECTION 4 LANDSCAPING WORKS 4.1 General 4.2 Definitions and Abbreviations 4.3 Relevant Codes and Standards 4.4 Materials 4.5 Submissions 4.6 Workmanship 4.7 Inspection, Testing and Commissioning APPENDIX A4.1 British Standards Publications SECTION 5 FENCING 5.1 General 5.2 Design and Performance Criteria 5.3 Materials 5.4 Submissions 5.5 Workmanship SECTION 6 DRAINAGE WORKS 6.1 General 6.2 Glossary of Terms 6.3 Materials 6.4 Submissions 6.5 Workmanship 6.6 Inspection, Testing and Commissioning APPENDIX A6.1 CCTV Inspection of Pipelines A6.1.1 Scope A6.1.2 Equipment A6.1.3 Procedure A6.1.4 Recording of Results APPENDIX A6.2 Determination of the Compaction Fraction Value of Aggregates for

Granular Bed A6.2.1 Scope A6.2.2 Apparatus A6.2.3 Procedure A6.2.4 Calculation A6.2.5 Reporting of Results APPENDIX A6.3 Determination of the Resistance to Fracture of Manhole Covers and

Gully Gratings A6.3.1 Scope A6.3.2 Equipment A6.3.3 Procedure A6.3.4 Reporting of Results


APPENDIX A6.4 Tests on Gravity Pipelines for Drainage Works A6.4.1 Scope A6.4.2 Equipment A6.4.3 Procedure: Before Tests and Inspections A6.4.4 Procedure: Water Test A6.4.5 Procedure: Air Test A6.4.6 Procedure: Visual Inspection A6.4.7 Procedure: Infiltration Test A6.4.8 Calculation A6.4.9 Reporting of Results APPENDIX A6.5 Tests On Pressure Pipelines For Drainage Works A6.5.1 Scope A6.5.2 Equipment A6.5.3 Procedure A6.5.4 Calculation A6.5.5 Reporting of Results SECTION 7 EARTHWORKS 7.1 Definitions and Abbreviations 7.2 Materials 7.3 Submissions 7.4 Workmanship 7.5 Inspection, Testing and Commissioning APPENDIX A7.1 Test Methods for Fill Material A7.1.1 General A7.1.2 Terms and Symbols A7.1.3 Grouping of Material APPENDIX A7.2 Determination of the Moisture Content of Fine Grained and Medium

Grained Material by the Microwave Oven Drying Method A7.2.1 Scope A7.2.2 Apparatus A7.2.3 Procedure A7.2.4 Calculation A7.2.5 Reporting of Results APPENDIX A7.3 Determination of the In-Situ Bulk Density and the In-Situ Dry Density

of Fine Grained And Medium Grained Material by the Nuclear Densometer Method

A7.3.1 Scope A7.3.2 Apparatus A7.3.3 Procedure: Comparability of Test Methods A7.3.4 Procedure: Routine Denosometer Check A7.3.5 Procedure: Determination of In-situ Bulk Density A7.3.6 Calculation A7.3.7 Reporting of Results


APPENDIX A7.4 Determination of the Maximum Converted Bulk Density by the HILF Method

A7.4.1 Scope A7.4.2 Apparatus A7.4.3 Procedure A7.4.4 Calculation A7.4.5 Reporting of Results APPENDIX A7.5 Adjustment of the Maximum Converted Bulk Density for the

Determination of the Relative Compaction A7.5.1 Scope A7.5.2 Apparatus A7.5.3 Procedure A7.5.4 Calculation A7.5.5 Reporting of Results SECTION 8 GEOTECHNICAL WORKS 8.1 General Requirements 8.2 Trials for Geotechnical Works 8.3 Definitions and Abbreviations – Ground Investigation 8.4 Submissions – Ground Investigation 8.5 Workmanship – Ground Investigation 8.6 Inspection, Testing and Commissioning – Ground Investigation 8.7 Materials – Slope Treatment Works 8.8 Submissions – Slope Treatment Works 8.9 Workmanship – Slope Treatment Works 8.10 Inspection, Testing and Commissioning – Slope Treatment Works 8.11 Definitions and Abbreviations – Grouting for Geotechnical Works 8.12 Materials – Grouting for Geotechnical Works 8.13 Submissions – Grouting for Geotechnical Works 8.14 Workmanship – Grouting for Geotechnical Works 8.15 Inspection, Testing and Commissioning – Grouting for Geotechnical

Works 8.16 Definitions and Abbreviations – Groundwater Drainage and Control 8.17 Materials– Groundwater Drainage and Control 8.18 Submissions – Groundwater Drainage and Control 8.19 Workmanship – Groundwater Drainage and Control 8.20 Inspection, Testing and Commissioning – Groundwater Drainage and

Control 8.21 Definitions and Abbreviations – Geotechnical Instrumentation 8.22 Materials – Geotechnical Instrumentation 8.23 Submissions – Geotechnical Instrumentation 8.24 Workmanship – Geotechnical Instrumentation 8.25 General – Laboratory Work 8.26 Workmanship – Laboratory Work 8.27 Inspection, Testing and Commissioning – Laboratory Work


APPENDIX A8.1 “GEO” Probe Test A8.1.1 Scope A8.1.2 Apparatus A8.1.3 Procedure A8.1.4 Reporting of Results APPENDIX A8.2 Determination of the Flow of Grout A8.2.1 Scope A8.2.2 Apparatus A8.2.3 Procedure: Calibration A8.2.4 Procedure: Flow Test A8.2.5 Calculation A8.2.6 Reporting of Results SECTION 9 CARRIAGEWAYS: SUB-BASE MATERIAL AND BITUMINOUS

MATERIALS 9.1 Definitions and Abbreviations 9.2 Design and Performance Criteria 9.3 Materials 9.4 Submissions 9.5 Workmanship 9.6 Inspection, Testing and Commissioning APPENDIX A9.1 Determination of the Permeability of Friction Course Material A9.1.1 Scope A9.1.2 Apparatus A9.1.3 Procedure A9.1.4 Reporting of Results SECTION 10 CONCRETE CARRIAGEWAYS 10.1 General 10.2 Materials 10.3 Submissions 10.4 Workmanship 10.5 Inspection, Testing and Commissioning APPENDIX A10.1 Determination of the Texture Depth Of Carriageways A10.1.1 Scope A10.1.2 Materials A10.1.3 Apparatus A10.1.4 Procedure A10.1.5 Calculation A10.1.6 Reporting of Results


SECTION 11 MISCELLANEOUS ROADWORKS 11.1 General 11.2 Design and Performance Criteria 11.3 Materials 11.4 Submissions 11.5 Workmanship 11.6 Inspection, Testing and Commissioning APPENDIX A11.1 Determination of Characteristic Compressive Strength of Interlocking

Blocks A11.1.1 Scope A11.1.2 Apparatus A11.1.3 Procedure A11.1.4 Calculation A11.1.5 Reporting of Results SECTION 12 TRAFFIC SIGNS, ROAD MARKINGS AND ROAD STUDS 12.1 General 12.2 Definitions and Abbreviations 12.3 Relevant Codes and Standards 12.4 Materials 12.5 Submissions 12.6 Workmanship 12.7 Inspection, Testing and Commissioning SECTION 13 WORK FOR ELECTRICAL AND MECHANICAL INSTALLATIONS 13.1 General 13.2 Materials 13.3 Workmanship 13.4 Inspection, Testing and Commissioning SECTION 14 WATER SUPPLY PIPEWORKS 14.1 General 14.2 Definitions and Abbreviations 14.3 Materials 14.4 Submissions 14.5 Workmanship 14.6 Inspection, Testing and Commissioning APPENDIX A14.1 Pressure Tests on Pipelines A14.1.1 Scope A14.1.2 Equipment A14.1.3 Procedure A14.1.4 Calculation A14.1.5 Reporting of Results


SECTION 15 NOT USED

SECTION 16 NOT USED

SECTION 17 PILING WORKS

17.1 General 17.2 Definitions and Abbreviations 17.3 Relevant Codes and Standards 17.4 Materials 17.5 Submissions 17.6 Workmanship 17.7 Inspection Testing and Commissioning

APPENDIX A17.1 Determination of the Load Defection Characteristics of Piles by Load

Test A17.1.1 Scope A17.1.2 Equipment A17.1.3 Procedure: Before Testing A17.1.4 Procedure: Load Test A17.1.5 Procedure: After Testing A17.1.6 Reporting of Results APPENDIX A17.2 Pile Driving Record (Prefabricated Steel and Driven Cast-in-place

Piles) APPENDIX A17.3 Pile Records (Bored Cast-in-place Piles) APPENDIX A17.4 Pile Records (Barrettes) APPENDIX A17.5 Bentonite Slurry Records APPENDIX A17.6 Pile Load Test Records (Test Result)

SECTION 18 FORMWORK AND FINISHES TO CONCRETE 18.1 General 18.2 Definitions and Abbreviations 18.3 Design and Performance Criteria 18.4 Materials 18.5 Submissions 18.6 Workmanship 18.7 Inspection, Testing and Commissioning

SECTION 19 STEEL REINFORCMENT 19.1 Definitions and Abbreviations 19.2 Materials 19.3 Submissions 19.4 Workmanship 19.5 Inspection Testing and Commissioning


SECTION 20 CONCRETE AND JOINTS IN CONCRETE 20.1 General 20.2 Definitions and Abbreviations 20.3 Relevant Codes and Standards 20.4 Design and Performance Criteria 20.5 Materials 20.6 Submissions 20.7 Workmanship 20.8 Inspection, Testing and Commissioning APPENDIX A20.1 Determination of the Efficiency Index of Curing Compounds A20.1.1. Scope A20.1.2. Materials A20.1.3. Apparatus A20.1.4. Procedure: Preparation of Specimens A20.1.5. Procedure: Determination of Efficiency Index A20.1.6. Calculation A20.1.7. Reporting of Results APPENDIX A20.2 Determination of the Deflection, Recovery and Resistance to Cracking

of Precast Units A20.2.1 Scope A20.2.2 Equipment A20.2.3 Procedure A20.2.4 Reporting of Results APPENDIX A20.3 Determination of the Disintegration and Shrinkage, the Recovery

Value and Reduction in Mass, and the Extrusion of Joint Filler A20.3.1 Scope A20.3.2 Apparatus A20.3.3 Procedure: Weathering Test A20.3.4 Procedure: Compression and Recovery Test A20.3.5 Procedure: Extrusion Test A20.3.6 Calculation A20.3.7 Reporting of Results APPENDIX A20.4 Routine Checks for Plant and Equipment PART 1 Batching and Mixing Equipment A20.4.1 Daily Routine A20.4.2 Weekly Routine A20.4.3 Monthly Routine A20.4.4 Quarterly Routine PART 2 Transporting Equipment – Mixer and Agitator Units A20.4.5 Daily Routine A20.4.6 Monthly Routine


SECTION 21 PRESTRESSING 21.1 General 21.2 Definitions and Abbreviations 21.3 Materials 21.4 Submissions 21.5 Workmanship 21.6 Inspection Testing and Commissioning SECTION 22 STEELWORK 21.7 General 21.8 Relevant Codes and Standards 21.9 Materials 21.10 Submissions 21.11 Workmanship 21.12 Inspection Testing and Commissioning SECTION 23 BRIDGEWORKS 23.1 General 23.2 Definitions and Abbreviations 23.3 Design and Performance Criteria 23.4 Materials 23.5 Submissions 23.6 Workmanship 23.7 Inspection Testing and Commissioning APPENDIX A23.1 Friction Test for Bridge Bearings A23.1.1 Scope A23.1.2 Equipment A23.1.3 Procedure A23.1.4 Calculation A23.1.5 Reporting of Results SECTION 24 WATER RETAINING STRUCTURES 24.1 General 24.2 Definitions and Abbreviations 24.3 Materials 24.4 Submissions 24.5 Workmanship 24.6 Inspection Testing and Commissioning

General Materials & Workmanship Specification 1/24 January 2011 Issue No. 5, Volume 1 – Civil & Structural Works Section 1 – General – Civil & Structural Works

SECTION 1 GENERAL – CIVIL AND STRUCTURAL WORKS 1.1 DEFINITIONS & ABBREVIATIONS 1.1.1 Definitions

Words and expressions, to which meanings have been assigned in the General Conditions and General Specification, shall have the same meanings in this volume.

1.1.2 Abbreviations

Abbreviations in this volume shall have the following meanings: AAR Alkali-Aggregate Reaction ACI American Concrete Institution Standard AOAC Association of Analytical Chemistry APHA American Public Health Authority ASSHTO American Association of State Highway and Transportation Officials AWWA American Water Works Association ASTM American Society for Testing and Material BS British Standard CAPWAP CASE Pile Wave Analysis Program CCTV closed circuit television CD chart datum CI cast iron CIRIA Construction Industry Research and Information Association CP British Standard Code of Practice CS Construction Standard C&D Construction and Demolition DI ductile iron DN nominal size Dn nominal size of tees and tapers FGL finished ground level, or finished level of permanent works GEO Geotechnical Engineering Office, Civil Engineering Department

(Hong Kong Government) GGBFS Ground Granulated Blast Furnace Slag GI galvanised iron GIFW Ground Investigation Field Work GRC glassfibre reinforced concrete HDPE high density polyethylene HOKLAS Hong Kong Laboratory Accreditation Scheme HKQAA Hong Kong Quality Assurance Agency


HSFG high strength friction grip IRHD International Rubber Hardness Degree ISO International Organisation for Standardization OPC ordinary Portland cement PD Principal Datum PFA pulverised-fuel ash PPFAC Portland pulverised-fuel ash cement PNAP Practice Note for Authorised Persons and Registered Structural

Engineers Ppm parts per million PTFE polytertrafluroethylene PVC polyvinyl chloride QSPSC Quality Scheme for the Production and Supply of Concrete RHPC rapid hardening Portland cement RSC Registered Specialist Contractor SIL Standard Inter-departmental Landscape Technical Group SIS Swedish Standard SRPC sulphate resisting Portland cement UPVC Unplasticised polyvinyl chloride

1.2 RELEVANT CODES AND STANDARDS 1.2.1 General

The Standards and Codes of Practice specified in this section are listed below for information only. The Contractor shall comply with the edition of the Standard or Code of Practice listed in the text when stated, or the latest edition when no edition is listed. Where British Standards have been replaced by the new BS EN documents, the old BS number is retained in the text, with the new BS EN number listed below.

1.2.2 British Standards

BS 4 Structural steel sections

BS 4 : Part 1 : 1993 Structural steel sections. Specification for hot-rolled sections

BS 12 : 1989 (1996)_

(replaced by BS EN 197-1:2000)

Specification for Portland cements

BS 21 : 1985 Specification for pipe threads for tubes and fittings where pressure - tight joints are made on the threads (metric dimensions)

BS 29 : 1987(replaced by BS EN 10250-2:2000)

Specification for carbon steel forgings above 150 mm ruling section


BS 65 : 1988 (replaced by BS 65:1991)

Specification for vitrified clay pipes, fittings, joints and ducts

BS 144 : 1997 Wood preservation using coal tar creosotes

BS 373 :1986 Methods of testing small clear specimens of timber

BS 381C:1996 Specification for colours for identification, coding and special purposes

BS 410 : 1986 Specification for test sieves

BS 416 : 1990 Discharge and ventilating pipes and fittings, sand-cast or spun in cast iron

BS 417 : Part 2 : 1987 Specification for galvanized low carbon steel cisterns, cistern lids, tanks and cylinders - metric units

BS 427 : 1990 (replaced by BS EN ISO 6507-1-3:1998)

Method for Vickers hardness test and for verification of Vickers hardness testing machines

BS 434 : 1990 Bitumen road emulsions (anionic and cationic)

BS 434 : Part 1 : 1984 Specification for bitumen road emulsions

BS 434 : Part 2 : 1984 Code of practice for use of bitumen road emulsions

BS 443 :1990 (replaced by BS EN 10244-2:2001)

Specification for testing zinc coatings on steel wire and for quality requirements

BS 449 : Part 2 : 1969 Specification for the use of structural steel in building - metric units

BS 534 : 1990 Specification for steel pipes, joints and specials for water and sewage

BS 544 : 1969 Specification for linseed oil putty for use in wooden frames

BS 639: 1986 Specification for covered carbon and carbon manganese steel electrodes for manual metal-arc welding

BS 718 : 1985 (replaced by BS 718 : 1991)

Specification for density hydrometers

BS 729 : 1986(replaced by BS EN ISO 1461:1999)

Specification for hot dip galvanized coatings on iron and steel articles

BS 743 : 1970 (replaced by BS 6398:1983 , BS 6515:1984 and BS 8215:1991)

Specification for materials for damp-proof courses

BS 747 : 2000 Specification for roofing felts

BS 812 Testing aggregates

BS 812 : Part 1 : 1975 (replaced by BS EN 932-1:1997)

Testing aggregates. Methods for determination of particle size and shape



Methods for determination of physical properties


Chemical properties

BS 812 : Part 4 : 1976 Sampling and testing of mineral aggregates, sands and fillers

BS 812 : Part 101 : 1984 Guide to sampling and testing aggregates


Methods for sampling

BS 812 : Part 103: 1985 Methods for determination of particle size distribution

BS 812 : Section 103.1 : 1985

Sieve tests

BS 812 : Section 103.2 : 1989

Sedimentation test

BS 812 : Part 105 Methods for determination of particle shape

BS 812 : Section 105.1 : 1989

Testing aggregates. Methods for determination of particle shape. Flakiness index

BS 812 : Section 105.2 : 1990

Elongation index of coarse aggregate


Methods for determination of aggregate crushing value (ACV)


Methods for determination of ten per cent fines value (TFV)


Method for determination of aggregate impact value (AIV)


Method for determination of aggregate abrasion value (AAV)

BS 812-117: 1988 Testing aggregates. Method for determination of water-soluble chloride salts

BS 812-2: 1995 Testing aggregates. Methods for determination of density

BS 864 : Part 2 : 1983 (replaced by BS EN 1254-1-2:1998)

Specification for capillary and compression fittings for copper tubes

BS 873 Road traffic signs and internally illuminated bollards

BS 873 : Part 1 : 1983 Methods of test



Specification for internally illuminated signs and external lighting luminaries

BS 873 : Part 6 : 1983 (replaced by BS EN 12899-1:2001

Specification for retroreflective and non-retroreflective signs

BS 873 : Part 7 : 1984 Specification for posts and fittings

BS 882 : 1992 Specification for aggregates from natural sources for concrete

BS 890 : 1995 Specification for building limes

BS 903 Physical testing of rubber

BS 903 : Part A1 1996 Physical testing of rubber. Determination of density

BS 903 : Part A2 : 2002 Physical testing of rubber. Determination of tensile stress-strain properties

BS 903 : Part A3 : 1995 Determination of tear strength (trouser, angle and crescent test pieces)

BS 903 : 1997 Determination of compression stress-strain properties

BS 903 : Part A5 : 1974 (replaced by BS ISO 2285:2001)

Determination of tension set

BS 903-A5:1997 Physical testing of rubber. Determination of tension set at normal and high temperatures

BS 903 : Part A6 : 1992(1998)

Determination of compression set after constant strain

BS 903 : Part A9 : 1988 Determination of abrasion resistance

BS 903 : Part A16 : 1999 Determination of the effect of liquids

BS 903 : Part A18 : 1998 Physical testing of rubber Determination of equilibrium water vapour absorption

BS 903 : Part A19 : 1994 Heat resistance and accelerated ageing tests

BS 903 : Part A26 : 1994 Determination of hardness

BS 903-A26:1995 Physical testing of rubber. Method for determination of hardness (hardness between 10 IRHD and 100 IRHD)

BS 903 : Part A43 : 1990(2002)

Method for determination of resistance to ozone cracking (static strain test)

BS 903 : Part C2 : 1982(1995)

Determination of volume resistivity


BS 907-1 : 1996 Specification for wrought steels for mechanical and allied engineering purposes. General inspection and testing procedures and specific requirements for carbon, carbon manganese, alloy and stainless steels

BS 952 Glass for glazing

BS 952 : Part 1 :: 1995 Classification

BS 952 : Part 2 : 1980 Terminology for work on glass

BS 970 : Part 1 : 1983 (replaced by BS EN 10084:1998, BS EN 10085:2001, BS EN 10087:1999, BS EN 10095:1999 and BS EN 10250-4:2000)

General inspection and testing procedures and specific requirements for carbon, carbon manganese, alloy and stainless steels

BS 1004 : 1972 (1985) (replaced by BS EN 12844:1999 and BS EN 1774:1998)

Specification for zinc alloys for die casting and zinc alloy die casting

BS 1010 : Part 2 : 1973 Draw-off taps and above-ground stopvalves

BS 1014 : 1975 (1986) (replaced by BS EN 12878:1999)

Specification for pigments for Portland cement and Portland cement products

BS 1070 : 1973(2000) Specification for black paint (tar-based)

BS 1154 : 1992 Specification for natural rubber compounds

BS 1155 : 1992(1997) Specification for natural rubber compounds for extrusion

BS 1161 : 1977(1991) Specification for aluminium alloy sections for structural purposes

BS 1181 : 1999 Specification for clay flue linings and flue terminals

BS 1191 Specification for gypsum building plasters

BS 1191 : Part 1 :1973(1994)

Excluding premixed lightweight plasters

BS 1194 : 1999 Specification for concrete porous pipes for under-drainage

BS 1199 and 1200 : 1976 (replaced by BS EN 13139:2002)

Specification for building sands from natural sources

BS 1203 : 2001 Specification for synthetic resin adhesives (phenolic and aminoplastic) for plywood

BS 1204 Synthetic resin adhesives (phenolic and aminoplastic) for wood


BS 1204 : Part 1 : 1979 (1991) (replaced by BS 1204:1993, BS EN 301:1992 and BS EN 302-1-4:1992)

Specification for gap-filling adhesives

BS 1212 Float operated valves

BS 1212 : Part 1 : 1990 Specification for piston type float operated valves (copper alloy body)(excluding floats)

BS 1212 : Part 2 : 1990 Specification for diaphragm type float operated valves (copper alloy body)(excluding floats)

BS 1212 : Part 3 : 1990 Specification for diaphragm type float operated valves (plastic bodied) for cold water services only (excluding floats)

BS 1247 : 1990 Manhole steps

BS 1305 : 1974 Specification for batch type concrete mixers

BS 1336 : 1971(2002) Specification for knotting

BS 1369 Steel lathing for internal plastering and external rendering

BS 1369 : Part 1 : 1987(1994)

Specification for expanded metal and ribbed lathing

BS 1377 : 1990 Methods of test for soils for civil engineering purposes (as modified in accordance with GEO Report No. 36, entitled "Methods of Test for Soils in Hong Kong for Civil Engineering Purposes (Phase 1 Tests)", except for Clauses 7.39(1) & 9.43(5) where the year of edition remains to be 1975)

BS 1387 : 1985 (1990) Specification for screwed and socketed steel tubes and tubulars and for plain end steel tubes suitable for welding or for screwing to BS 21 pipe threads

BS 1400 : 1985 (replaced by BS EN 1982:1999)

Specification for copper alloy ingots and copper alloy and high conductivity copper castings

BS 1449 : Part 1 : 1983 (replaced by BS 1449-1.1-1.5:1991 and BS EN 10130:1991)

Specification for carbon and carbon-manganese plate, sheet and strip

BS 1449 : Part 2 : 1983 (replaced by BS EN 10029:1991, BS EN 10048:1997, BS EN 10051:1992 BS EN 10095:1999 BS EN 10258:1997 and BS EN 10259:1997)

Steel plate, sheet and strip. Specification for stainless and heat-resisting steel plate, sheet and strip


Specification for flake graphite cast iron


BS 1470 : 1987 (replaced by BS EN 485-1-4:1994, BS EN 515:1993 and BS EN 573-1-4:1995)

Specification for wrought aluminium and aluminium alloys for general engineering purposes : plate, sheet and strip

BS 1471 : 1972 (replaced by BS EN 515:1993, BS EN 573-3-4:1995 and BS EN 754-1-2:1997,-7-8:1998)

Specification for wrought aluminium and aluminium alloys for general engineering purposes - drawn tube

BS 1473 : 1972 Specification for wrought aluminium and aluminium alloys for general engineering purposes - rivet, bolt and screw stock

BS 1474 : 1987 (replaced by BS EN 515:1993, BS EN 573-3-4:1995, BS EN 755-1-9:1996 and BS EN 12020-1-2:2001)

Specification for wrought aluminium and aluminium alloys for general engineering purposes : bars, extruded round tubes and sections

BS 1490 : 1988 Specification for aluminium and aluminium alloy ingots and castings for general engineering purposes

BS 1494 : Part 2 : 1967 (withdrawn)

Sundry fixings

BS 1610 : 1985 (replaced by BE EN ISO 7500-1:1999, BS EN 10002-3:1995 and BS EN ISO 7500-2:1999)

Materials testing machines and force verification equipment

BS 1615 : 1987 (replaced by BS EN 12373-1:2001)

Method for specifying anodic oxidation coatings on aluminium and its alloys

BS 1706 : 1990 Method for specifying electroplated coatings of zinc and cadmium on iron and steel

BS 1722 : Part 1: 1999 Specification for chain link fences

BS 1740 : Part 1 : 1971 (1990) (replaced by BS EN 10241:2000)

Specification for wrought steel pipe fitting (screwed BS 21 R-series thread)

BS 1881-124: 1988 Testing concrete. Methods for analysis of hardened concrete

BS 1924 : 1990 Stabilized materials for civil engineering purposes

BS 2000 Methods of test for petroleum and its products

BS 2015 : 1965 (1985) (replaced by BS 2015 : 1992 (2000) and BS EN 971-1:1996)

Glossary of paint terms


BS 2451 : 1963 (1988) (replaced by BS EN ISO 11124-3:1997, BS 7079-4:1994)

Specification for chilled iron shot and grit

BS 2456: 1990 Specification for floats (plastics) for float operated valves for cold water services

BS 2494 : 1990 (replaced by BS 2494 : BS 7874:1998, BS EN 681-1-2:1996 and BS EN 682:2002)

Specification for elastomeric seals for joints in pipework and pipelines

BS 2499 1-3:1992 Specification for hot applied joint sealants for concrete pavements

BS 2523 : 1996(2000) Specification for lead-based priming paints

BS 2569 : Part 1 : 1964 (1988) (replaced by BS EN 22063:1994)

Specification for sprayed metal coatings. Protection of iron and steel by aluminium and zinc against atmospheric corrosion

BS 2600 Radiographic examination of fusion welded butt joints in steel

BS 2600 : Part 1 : 1983 (replaced by BS EN 1435:1997)

Methods for steel 2 mm up to and including 50 mm thick


Methods for steel over 50 mm up to and including 200 mm thick

BS 2633 : 1987(2001) Specification for Class I arc welding of ferritic steel pipework for carrying fluids

BS 2648 : 1995(2000) Performance requirements for electrically-heated laboratory drying ovens

BS 2752 : 1990 Specification for chloroprene rubber compounds

BS 2760 : 1973 Specification for pitch-impregnated fibre pipes and fittings for below and above ground drainage

BS 2782 Methods of testing plastics

BS 2782-3 : 2002 Mechanical properties

BS 2782-4 : 1983 Chemical properties

BS 2782-6 : 1991 Dimensional properties

BS 2782 : Part 3 :

Methods 320A to 320F : 1976(1996)

Tensile strength, elongation and elastic modulus

BS 2782 : Part 3 :

Method 365A : 1976(2002)

Determination of softness number of flexible plastics materials


BS 2782 : Part 3 :

Method 365D : 1997

Determination of hardness of plastics and ebonite by the ball indentation method

BS 2782 : Part 4 :

Methods 430A to 430D : 1983

Determination of water absorption at 23°C.

Determination of water absorption at 23°C with allowance for water-soluble matter.

Determination of boiling water absorption.

Determination of boiling water absorption with allowance for water-soluble matter.

BS 2782 : Part 6 :

Methods 620A to 620D : 1980 (replaced by BS 2782 : Part 6 : Methods 620A to 620D : 1991 and BS EN ISO 1183-3:1999)

Determination of density of solid plastics excluding cellular plastics (immersion method).

Determination of density of solid plastics excluding cellular plastics (pyknometer method).

Determination of plastics (sink-float method).

Determination of density of solid plastics excluding cellular plastics (density gradient column method).


Specification for spheroidal graphite or nodular graphite cast iron

BS 2846 : Part 3 : 1975 (1985)

Determination of a statistical tolerance interval

BS 2846 : Part 4 : 1976 (1985)

Techniques of estimation and tests relating to means and variances

BS 2869 : Part 2 : 1998 Specification for fuel oil for agricultural and industrial engines and burners (classes A2, C1, C2, D, E, F, G and H)


Copper tubes for water, gas and sanitation

BS 2874 : 1986 (replaced by BS EN 12163:1998, BS EN 12164:1998 and BS EN 12167:1998)

Specification for copper and copper alloy rods and sections (other than forging stock)

BS 2901 : Part 1 : 1983 Filler rods and wires for gas-shielded arc welding. Ferritic steels


Methods for radiographic examination of fusion welded circumferential butt joints in steel pipes


Specification for continuously hot-dip zinc coated and iron-zinc alloy coated steel : wide strip, sheet/plate and slit wide strip

BS 2989:1992 Specification for continuously hot-dip zinc coated and iron-zinc alloy coated steel flat products: tolerances on dimensions and shape



Specification for TIG welding of aluminum, magnesium and their alloys

BS 3019 : Part 2 : 1960 Austenitic stainless and heat resisting steels

BS 3049 : 1995 Specification for pedestrian guard rails (metal)

BS 3100 : 1991(2001) Specification for steel castings for general engineering purposes

BS 3148 : 1980 Methods of test for water for making concrete (including notes on the suitability of the water)


Specification for constituent materials and mixtures


Specification for application of material to road surfaces

BS 3382 : Part 1 and 2 1961(1998)

Plating thickness, sampling, inspection procedures, thickness determination, Resistance to corrosion, purity, adhesion, porosity, reduction of hydrogen embrittlement, finish and appearance, plating thickness, passivation. Cadmium on steel components. Zinc on steel components

BS 3410 : 1961 Specification for metal washers for general engineering purposes

BS 3416 : 1988(2000) Specification for bitumen-based coatings for cold application, suitable for use in contact with potable water

BS 3468 : 1986 Specification for austenitic cast iron

BS 3505 : 1986 (replaced by BS EN 1452-1-5:2000)

Specification for unplasticized polyvinyl chloride (PVC-U) pressure pipes for cold potable water

BS 3506 : 1969 Specification for unplasticized PVC pipe for industrial uses


Specification for MIG welding of aluminium and aluminium alloys

BS 3600 : 1976 (1988) (replaced by BS 3600 : 1997)

Specification for dimensions and masses per unit length of welded and seamless steel pipes and tubes for pressure purposes

BS 3601 : 1987(1993) Specification for carbon steel pipes and tubes with specified room temperature properties for pressure purposes

BS 3690 : Part 1 : 1989 (replaced by BS 3690 : Part 1 : 1989 and BS EN 12591:2000)

Specification for bitumens for roads and other paved areas

BS 3690 : Part 2 : 1989 (replaced by BS 3690 : Part 2 : 1989(1997))

Specification for bitumens for industrial purposes


BS 3692 : 1967 (replaced by BS 3692 : 2001)

Specification for ISO metric precision hexagon bolts, screws and nuts. Metric units

BS 3698 : 1964 (1979) (replaced by BS 3698 : 1964(2000))

Specification for calcium plumbate priming paints

BS 3892 : Part 1 : 1997 Pulverized-fuel ash. Specification for pulverized-fuel ash for use as a cementitious component in structural concrete. Specification for pulverized-fuel ash for use with Portland cement.

BS 3900 : Part E10 : 1979 (1989) (replaced by BS EN 24624:1993(2000))

Mechanical tests on paint films – Pull-off test for adhesion


Methods for ultrasonic examination of welds. Methods for manual examination of fusion welds in ferritic steels

BS 3923 : Part 2 : 1972 Methods for ultrasonic examination of welds. Automatic examination of fusion welded butt joints in ferritic steels

BS 3981 : 1976(2000) Specification. Iron oxide pigments for paints

BS 3987 : 1991 Specification for anodic oxide coatings on wrought aluminium for external architectural applications

BS 3998 : 1989 Recommendations for tree work

BS 4027 : 1996 Specification for sulphate-resisting Portland cement

BS 4072 : 1999 Wood preservation by means of copper/chromium/arsenic compositions

BS 4102 : 1990 and BS EN 10223-1,-4-6:1998

Specification for steel wire and wire products for fences

BS 4147 : 1980 (1987) Specification for bitumen-based hot-applied coating materials for protecting iron and steel, including suitable primers where required

BS 4168 : Part 1 : 1981 (replaced by BS EN ISO 4762:1998)

Hexagon socket screws and wrench keys: metric series. Specification for hexagon socket head cap screws

BS 4190 : 2000 (replaced by BS 4190 : 2001)

Specification for ISO metric black hexagon bolts, screws and nuts

BS 4211 : 1994 Specification for ladders for permanent access to chimneys, other high structures, silos and bins


BS 4232 : 1967 (replaced by BS 7079-0:1990, BS 7079-A1:1989, ISO 8501-1:1988, BS 7079:Part A1:Supplement 1:1989, BS EN ISO 8503-1:1995, BS 7079-C1:1989, BS EN ISO 8503-2:1995, BS 7079-C2:1989, BS EN ISO 8503-3:1995, BS 7079-C3:1989, BS EN ISO 8503-4:1995, BS 7079-C4:1989(1998))

Specification for surface finish of blast-cleaned steel for painting

BS 4254 : 1983 Specification for two-part polysulphide-based sealants

BS 4320 : 1968 Specification for metal washers for general engineering purposes. Metric series

BS 4345 : 1968 (1986) Specification for slotted angles

BS 4346 Joints and fittings for use with unplasticized PVC pressure pipes


Injection moulded unplasticized PVC fittings for solvent welding for use with pressure pipes, including potable water supply


Mechanical joints and fittings, principally of unplasticized PVC


Specification for solvent cement

BS 4360 : 1986 (replaced by BS 7613:1994, BS 7668:1994, BS EN 10029:1991, BS EN 10113-1-3:1993, BS EN 10155:1993 and BS EN 10210-1:1994)

Specification for weldable structural steels

BS 4393 : 1969 (1985) (replaced by BS 4393 : 1991)

Specification for tin or tin-lead coated copper wire

BS 4395 Specification for high strength friction grip bolts and associated nuts and washers for structural engineering

BS 4395 : Part 1 : 1969(1998)

Specification for high strength friction grip bolts and associated nuts and washers for structural engineering. General grade


BS 4395 : Part 2 : 1969(1998)

Specification for high strength friction grip bolts and associated nuts and washers for structural engineering. Higher grade bolts and nuts and general grade washers

BS 4395 : Part 3 : 1973 Higher grade bolts (waisted shank), nuts and general grade washers

BS 4447 : 1973 Specification for the performance of prestressing anchorages for post-tensioned construction

BS 4449 : 1978 (1984) (excluding AMD 4337 and AMD 4540 and clauses 12.2.1 and 12.2.2) (replaced by BS 4449:1997)

Specification for hot rolled steel bars and carbon steel bars for the reinforcement of concrete

BS 4461 : 1997 Specification for cold worked steel bars for the reinforcement of concrete

BS 4446 : 1989 (replaced by BS 8666:2000 and BS EN ISO 4066:2000)

Specification for scheduling, dimensioning, bending and cutting of steel reinforcement for concrete

BS 4482 : 1985 Specification for cold reduced steel wire for the reinforcement of concrete

BS 4483 : 1985 (1998) Specification for steel fabric for the reinforcement of concrete

BS 4486 : 1980 Specification for hot rolled and hot rolled and processed high tensile alloy steel bars for the prestressing of concrete

BS 4500 : Part 3 : 1973 ISO limits and fits. Working limits on untoleranced dimensions

BS 4504 : Section 3.1 : 1989 (replaced by BS EN 1092-1:2002, BS EN 1515-1:2000)

Circular flanges for pipes, valves and fittings (PN designated) - Specification for steel flanges

BS 4514 : 2001 Specification for unplasticized PVC soil and ventilating pipes, fittings and accessories

BS 4515 : 1984 (BS 4515 : 2000)

Specification for welding of steel pipelines on land and offshore

BS 4550 Methods of testing cement


Methods of testing cement – Sampling

BS 4550 : Part 2 : 1970 Methods of testing cement – Chemical tests

BS 4550 : Part 3 : 1978 Methods of testing cement – Physical tests

BS 4551 : 1980 Methods of testing mortars, screeds and plasters


BS 4568 Specification for steel conduit and fittings with metric threads of ISO form electrical installations

BS 4568 : Part 1 : 1970 Steel conduit, bends and couplers

BS 4568 : Part 2 : 1970 (1988) (replaced by BS EN 50086-1:1994)

Fittings and components

BS 4570 : 1985 Specification for fusion welding of steel castings

BS 4576 : Part 1 : 1989, BS EN 607:1996, BS EN 1462:1997 and BS EN 12200-1:2000

Unplasticized polyvinyl chloride (PVC-U) rainwater goods and accessories - Half-round gutters and pipes of circular cross-section

BS 4604 Specification for the use of high strength friction grip bolts in structural steelwork

BS 4604 : Part 1 : 1970 Specification for the use of high strength friction grip bolts in structural steelwork. Metric series. General grade

BS 4604 : Part 2 : 1970 Specification for the use of high strength friction grip bolts in structural steelwork. Metric series. Higher grade (parallel shank)

BS 4620 : 1970 (1988) Specification for rivets for general engineering purposes

BS 4622 : 1970 (1983) Specification for grey iron pipes and fittings

BS 4652 : 1970(2000) Specification for metallic zinc-rich priming paint (organic media)

BS 4660 : 2000 Specification for unplasticized polyvinyl chloride (PVC-U) pipes and plastics fittings of nominal sizes 110 and 160 for below ground gravity drainage and sewerage

BS 4662 : 1970 (1989) Specification for boxes for the enclosure of electrical accessories

BS 4677 : 1984(2001) Specification for arc welding of austenitic stainless steel pipework for carrying fluids

BS 4756 : 1998 Specification for ready mixed aluminium priming paints for woodwork

BS 4772 : 1988 (replaced by BS 4772 : BS EN 545:1995, BS EN 598:1995 and BS EN 969:1996)

Specification for ductile iron pipes and fittings

BS 4848 Specification for hot-rolled structural steel sections


Hollow sections



Equal and unequal angles


Bulb flats


Specification for non-metallic flat gaskets (including gaskets for flanges to BS 4772)


Specification for approval testing of welding procedures - Fusion welding of steel


Specification for approval testing of welders working to approved welding procedures - Fusion welding of steel

BS 4872 : Part 1 : 1982(1999)

Specification for approval testing of welders when welding procedure approval is not required - Fusion welding of steel

BS 4873 : 1986 Specification for aluminium alloy windows

BS 4921 : 1988(1994) Specification for sheradized coatings on iron or steel

BS 4933 : 1973 Specification for ISO metric black cup and countersunk head bolts and screws with hexagon nuts

BS 4942 : 1981 (replaced by BS EN 818-1:1996, BS EN 818-3:1999 and BS EN 818-7:2002)

Short link chain for lifting purposes

BS 5075 : Part 1 : 1982, BS EN 480 and BS EN 934

Concrete admixtures. Specification for accelerating admixtures, retarding admixtures and water reducing admixtures

BS 5075 : Part 3 : 1985, BS EN 480 and BS EN 934

Concrete admixtures. Specification for superplasticizing admixtures

BS 5135 : 1984 (replaced by BS EN 1011-1:1998 and BS EN 1011-2:2001)

Specification for arc welding of carbon and carbon manganese steels

BS 5150 : 1990 Specification for cast iron gate valves

BS 5154 : 1991 Specification for copper alloy globe, globe stop and check, check and gate valves

BS 5163 : 1986 1986(1991)

Specification for predominantly key-operated cast iron gate valves for waterworks purposes

BS 5212 : 1990 Cold applied joint sealant systems for concrete pavements

BS 5215 : 1986 Specification for one-part gun grade polysulphide-based sealants


BS 5252F : 1976 (1986) (replaced by BS 5252F : 1976(2002))

Colour matching fan

BS 5255 : 1989, BS EN 1329-1:2000, BS EN 1455-1:2000, BS EN 1519-1:2000, BS EN 1565-1:2000 and BS EN 1566-1:2000

Specification for thermoplastics waste pipe and fittings

BS 5268 : Part 2 : 2002 Structural use of timber - Code of practice for permissible stress design, materials and workmanship

BS 5284 : 1993 Methods. Sampling and testing mastic asphalt and pitchmastic used in building

BS 5289 : 1976 (1983) (replaced by BS EN 970:1997)

Code of practice. Visual inspection of fusion welded joints

BS 5328 Concrete

BS 5395 : Part 1 :2000 Code of practice for the design of straight stairs

BS 5400 Steel, concrete and composite bridges

BS 5400 : Part 2 : 1978, BS 5400-9.1-9.2:1983

Specification for loads

BS 5400 : Part 4 : 1990 Code of practice for design of concrete bridges

BS 5400 : Part 6 : 1980 (1999)

Steel, concrete and composite bridges. Specification for materials and workmanship, steel

BS 5400 : Part 9 : 1983 Bridge bearings

BS 5400 : Section 9.2 : 1983

Specification for materials, manufacture and installation of bridge bearings

BS 5481 : 1977 (1989) (replaced by BS EN 1401-1:1998)

Specification for unplasticized PVC pipe and fittings for gravity sewers

BS 5490 : 1977 Specification for classification of degrees of protection provided by enclosures

BS 5493 : 1977, BS EN ISO 12944-1-8:1998 and BS EN ISO 14713:1999

Code of practice for protective coating of iron and steel structures against corrosion

BS 5531 : 1988 Code of practice for safety in erecting structural frames

BS 5573 : 1996 Code of practice for safety precautions in the construction of large diameter boreholes for piling and other purposes

BS 5589 : 1989(1997) Code of practice for preservation of timber

BS 5756 : 1997 Specification for tropical hardwoods graded for structural use


BS 5812 Materials for plain bearings

BS 5896 : 1980 Specification for high tensile steel wire and strand for the prestressing of concrete

BS 5911 Precast concrete pipes, fittings and ancillary products

BS 5911 : Part 2 : 1982 Specification for inspection chambers and street gullies

BS 5911 : Part 3 : 1982 (replaced by BS 5911-110:1992)

Specification for pipes and fittings with ogee joints

BS 5911 : Part 100 : 1988 Specification for unreinforced and reinforced pipes and fittings with flexible joints

BS 5911 : -200:1994 Specification for unreinforced and reinforced manholes and soakaways of circular cross section

BS 5930 : 1981 (replaced by BS 5930 : 1999)

Code of practice for site investigations

BS 5931 : 1980 Code of practice for machine laid in situ edge details for paved areas

BS 5950-1 : 1990 Structural use of steelwork in building. Code of practice for design. Rolled and welded sections

BS 5950 -2:2001 Structural use of steelwork in building. Specification for materials, fabrication and erection : hot rolled sections; and Rolled & welded sections

BS 5950-3 : 1990 Code of practice for design of simple and continuous composite beams

BS 5950-4 : 1994 Code of practice for design of composite slabs with profiled steel sheeting

BS 5950-5 : 1998 Code of practice for design of cold formed thin gauge sections

BS 5950-6 : 1995 Code of practice for design of light gauge profiled steel sheeting

BS 5950-7 : 1990 Structural use of steelwork in building. Specification for materials and workmanship: cold formed sections

BS 5975 : 1996 Code of practice for falsework


Methods for ultrasonic testing and specifying quality grades of ferritic steel plate

BS 5996:1993 Specification for acceptance levels for internal imperfections in steel plate, strip and wide flats, based on ultrasonic testing

BS 6044 : 1987 (replaced by BS EN 1436:1998 and BS EN 1871:2000)

Specification for pavement marking paints


BS 6072 : 1981 (1986) (replaced by BS EN ISO 9934-1:2001)

Method for magnetic particle flaw detection

BS 6088 : 1981 (1985) (replaced by BS 6088:1981(1993) and BS EN 1423:1998)

Specification for solid glass beads for use with road marking compounds and for other industrial uses

BS 6089 : 1981 Guide to assessment of concrete strength in existing structures

BS 6105 : 1981 (replaced by BS EN ISO 3506-1-2:1998)

Specification for corrosion-resistant stainless steel fasteners

BS 6150 : 1991 Code of practice for painting of buildings

BS 6232 Thermal insulation of cavity walls by filling with blown man-made mineral fibre

BS 6262-4: 1994 Code of practice for glazing for buildings

BS 6323 : 1982 (1990) Specification for seamless and welded steel tubes for automobile, mechanical and general engineering purposes

BS 6323 : Part 1 : 1982 (1990)

Specification for seamless and welded steel tubes for automobile, mechanical and general engineering purposes. General requirements

BS 6323 : Part 3 : 1982 (1990)

Specific requirements for hot finished seamless steel tubes

BS 6323 : Part 8 : 1982 (1990)

Specification for seamless and welded steel tubes for automobile, mechanical and general engineering purposes. Specific requirements for longitudinally welded stainless steel tubes

BS 6349 1:2000 Code of practice for maritime structures – General criteria

BS 6362 : 1990(2001) Specification for stainless steel tubes suitable for screwing in accordance with BS 21 'Pipe threads for tubes and fittings where pressure-tight joints are made on the threads'

BS 6363 : 1983 Specification for welded cold formed steel structural hollow sections

BS 6404 Magnetic materials

BS 6405 : 1984(1998) Specification for non-calibrated short link steel chain (grade 30) for general engineering purposes : class 1 and 2

BS 6431 Ceramic floor and wall tiles

BS 6431 : Part 1 : 1983(1996)

Specification for classification and marking, including definitions and characteristics


BS 6431 : Part 2 : 1984(1996)

Specification for extruded ceramic tiles with a low water absorption (E ≤ 3%). Group A1

BS 6431 : Part 3 Extruded ceramic tiles with a water absorption of 3% < E ≤ 6%. Group A11a

BS 6431 : Part 3 : Section 3.1 : 1986(1996)

Specification for general products

BS 6431 : Part 3 : Section 3.2 : 1986(1996)

Specification for products (terre cuite, cotto, baldosin catalan)

BS 6431 : Part 4 Extruded ceramic tiles with a water absorption of 6% < E ≤ 10%. Group A11b

BS 6431 : Part 4 : Section 4.1 : 1986(1996)

Specification for general products

BS 6431 : Part 4 : Section 4.2 : 1986(1996)

Specification for specific products (terre cuite, cotto, baldosin catalan)

BS 6443 : 1984 (replaced by BS EN 571-1:1997)

Method for penetrate flaw detection

BS 6463 Quicklime, hydrated lime and natural calcium carbonate

BS 6463 -101:1996 Methods of sampling

BS 6463 -102:2001 Methods of chemical analysis

BS 6463 -103:1999 Methods of test for physical properties of hydrated lime and lime putty

BS 6510 : 1984 Specification for steel windows, sills, window boards and doors

BS 6558 : 1985 (replaced by BS EN 187000:1994 and BS EN 187000:1994)

Optical fibres and cables

BS 6566 (replaced by BS EN 636-1-3:1997)

Plywood

BS 6588 : 1985 (1996) (replaced by BS EN 197-1:2000)

Specification for Portland pulverized-fuel ash cement

BS 6657 : 1991 Guide for prevention of inadvertent initiation of electro-explosive devices by radio-frequency radiation


Specification for malleable cast iron

BS 6700 : 1997 Specification for design, installation, testing and maintenance of services supplying water for domestic use within buildings and their cartilages

BS 6780 : 1986 Specification for through thickness reduction of area of steel plates and wide flats


BS 6925 : 1988 Specification for mastic asphalt for building and civil engineering (limestone aggregate)

BS 6949 : 1991(2000) Specification for bitumen-based coatings for cold application, excluding use in contact with potable water

BS 7295 Fusion bonded epoxy coated carbon steel bars for the reinforcement of concrete

BS 7263 : 1990 Precast concrete flags, kerbs, channels, edgings and quadrants

BS 7263 : Part 1 : 1990 (replaced by BS 7263-1:2001 and BS 7263-3:2001)

Specification

BS 8004 : 1986 Code of practice for foundations


Guide to new sewerage construction

BS 8110 : 1985 Structural use of concrete

BS 8118 : Part 2 : 1991 Specification for materials, workmanship and protection

BS EN 10025 : 1993 Hot rolled products of non-alloy structural steels. Technically delivery conditions

CP 144 Roof coverings

CP 144 : Part 4 : 1970 (replaced by BS 8218:1998)

Mastic asphalt. Metric units

1.2.3 American Standards

AASHTO Designation M252-81

Standard specification for corrugated polyethylene drainage tubing

ASTM A775 Standard specification for epoxy-coated reinforcing steel bars

ASTM A 775M (replaced by ASTMa775m-01)

Specification for epoxy-coated reinforcing steel bars

ASTM C 127-88 (replaced by ASTMC127-01)

Test method for specific gravity and absorption of coarse aggregate

ASTM C 128-88 (replaced by ASTM C128-01)

Test method for specific gravity and absorption of fine aggregate

ASTM C 138-81 (1987) (replaced by ASTM C131-01)

Test method for resistance to degradation of small-size coarse aggregate by abrasion and impact in the Los Angeles Machine


ASTM C 136-84A (replaced by ASTM c136-01)

Method for sieve analysis of fine and coarse aggregates

ASTM C 188-84 (replaced by ASTM c188-95)

Test method for density of hydraulic cement

ASTM C-494 Type C Standard specification for chemical admixtures for concrete – Type C – Accelerating admixtures

ASTM C 939-87 (replaced by ASTM c939-97)

Test method of flow of grout for preplaced-aggregate concrete

ASTM C 939-94 Standard test method for flow of grout for preplaced-aggregate concrete (flow cone method)

ASTM D 5-86 (replaced by ASTM d5-97)

Test method for penetration of bituminous materials


Test method for ductility of bituminous materials


Method for sampling bituminous materials

ASTM D 242-85 (replaced by ASTM d242-95(2000)e1)

Specification for mineral filler for bituminous paving mixtures

ASTM D 512-81, Method B

Standard test methods for chloride ion in water

ASTM D 516-80, Method A

Standard test method for sulfate ion in water

ASTM D 546-88 (replaced by ASTM d546-99e1)

Method for sieve analysis of mineral filler for road and paving materials

ASTM D 854-83 (replaced by ASTM d854-00e1)

Test method for specific gravity of soils

ASTM D 946-82 (replaced by ASTM d946-82(1999))

Specification for penetration-graded asphalt cement for use in pavement construction


Methods for sampling bituminous paving mixtures

ASTM D 1293-78 Standard test methods for pH of water

ASTM D 1559-82 (replaced by ASTM (discontinued))

Test method for resistance to plastic flow of bituminous mixtures using Marshall apparatus


Test method for effect of heat and air on asphaltic materials (thin-film over test)


Classification system for rubber products in automobile applications

ASTM D 2027-76 (1986) (replaced by d2027-97)

Specification for cutback asphalt (medium-curing type)


ASTM D 2041-78 (replaced by d2041-00)

Test method for theoretical maximum specific gravity of bituminous paving mixtures

ASTM D 2042-81 (1985) (replaced by d2042-01)

Test method for solubility of asphalt materials in trichloroethylene


Test method for viscosity of asphalts by vacuum capillary

ASTM D 2172-88 (replaced by d2172-01e1)

Test method for quantitative extraction of bitumen from bituminous paving mixtures


Test method for bulk specific gravity of compacted bituminous mixtures using saturated surface-dry specimens

ASTM D 3203-88 (replaced by d3203-94(2000))

Test method for percent air voids in compacted dense and open bituminous paving mixtures


Test method for specific gravity or density of semi-solid and solid bituminous materials by nickel crucible

AWWA C 203-86 Coal-tar enamel protective coatings for steel water pipes

1.2.4 Hong Kong Standards and Codes of Practice

CS1 : 1990 Testing concrete CS2 : 1995 Carbon steel bars for the reinforcement of concrete PNAP Practice note for authorized persons and registered

structural engineer PNAP 1 Buildings Department practice notes in force PNAP 66 Pile foundations PNAP 71 Demolition works – Measures for public safety PNAP 122 Testing of reinforcement for concrete PNAP 132 Site investigation and ground investigation PNAP 161 Development in the area numbers 2 & 4 of

scheduled areas PNAP 187 Code of practice for the structural use of concrete

1987 PNAP 214 New contractor registration system and the

contractors registration committee PNAP 242 Quality supervision requirements for foundation

works PNAP 243 Construction and Demolition Waste Geospec 1 Model specification for prestressed ground anchors,

2nd edition (1989) Geospec 3 Model specification for soil testing Geoguide 1 Guide to retaining wall design 2nd Edition Geoguide 2 Guide to site investigation (1987)


Geoguide 3 Guide to rock and soil descriptions (1988) Geoguide 6 Guide to reinforced fill structure and slope design GEO Report No.36 Methods of test for soils in Hong Kong for civil

engineering purposes (Phase 1) tests (1994) GCO 1/90 Review of design methods for excavation GCO 1/96 Pile design and construction Geotechnical manual for slopes, 2nd Edition Stormwater drainage manual Sewerage manual (Part 1) – Key planning issues and gravity collection system Sewerage manual (Part 2) – Pumping station and rising mains Drainage services department standard drawings Transport planning and design manual Code of practice for lighting, signing and guarding of road works Code of practice for site safety supervision Technical memorandum for site safety Public lighting design manual Structures design manual for highways and railways Guidelines on design of noise barriers Highways standard drawings Civil Engineering design manual Civil Engineering Department standard drawings

1.2.5 Other International Standards

Swedish Standards

SIS 05 59 00 Surface preparation standard for painting steel surfaces

General Materials & Workmanship Specification 1/14 January 2011 Issue No. 5, Volume 1 – Civil & Structural Works Section 2 – Temporary Works

SECTION 2 TEMPORARY WORKS 2.1 INTRODUCTION 2.1.1 This Section specifies materials and workmanship required for the design and

construction of Temporary Works. 2.1.2 Any details of Temporary Works shown on the Employer’s Drawings are for

reference only and such details shall not relieve or reduce the Contractor’s full design responsibility for all Temporary Works under the Contract.

2.2 DESIGN AND PERFORMANCE CRITERIA 2.2.1 Design

(a) Unless otherwise stated in the Contract, Temporary Works shall be designed by the Contractor who shall submit for the Project Manager's review without objection copies of calculations and drawings of the Temporary Works in accordance with the requirements stated in the Contract.

(b) The Contractor shall design Temporary Works in accordance with the

principles of BS 5975 except that the criteria as set out in Appendix A2.2 shall prevail when designing for Hong Kong conditions.

(c) Where appropriate, Temporary Works design shall comply with the

requirements of the Building Ordinance.

2.2.2 Temporary Works Co-ordinator

(a) The Contractor shall appoint a person "the Temporary Works Co-ordinator" whose duties shall in general follow the recommendations of Clause 10.2.2 of BS 5975. The Contractor shall submit for review without objection by the Project Manager the details and duties of the Temporary Works Co-ordinator.

(b) The Temporary Works Co-ordinator shall certify the design, loading, and

dismantling of falsework in accordance with Appendices A2.2 and A2.3. 2.2.3 Checking Engineer

Unless the Contract provides expressly to the contrary, the design of the Temporary Works shall be checked and certified as being satisfactory by the Checking Engineer in accordance with Appendices A2.2 and A2.3; and all the certificates endorsed by the Checking Engineer in relation thereto shall be submitted to the Project Manager for review without objection.

2.2.4 Method

The Contractor shall submit for the Project Manager's review without objection, method statements giving full details of materials, Contractor's Equipment and timing and sequence of operations involved in the construction of Temporary Works.


2.2.5 Construction and Removal

(a) Temporary Works shall be constructed to the same workmanship and quality standards as the Permanent Works save that the Temporary Works need not be new.

(b) The Contractor shall ensure that the Temporary Works are constructed, used

and removed in accordance with the certified design. If the Contractor wishes to change the construction, use or removal of the Temporary Works he shall submit to the Project Manager for review without objection details of such changes together with further certification in accordance with Appendices A2.2 and A2.3. Such details shall be reviewed without objection by the Project Manager before the Contractor implements any such change.

(c) Erection of falsework may not commence until the design has been certified

by the Temporary Works Co-ordinator and the Checking Engineer in accordance with Appendix A2.2.

(d) Loading or dismantling of falsework may not commence prior to certification

by the Temporary Works Co-ordinator and the Checking Engineer in accordance with Appendix A2.3.

(e) Temporary Works whether above or below ground or water level shall be

dismantled and completely removed after completion of the Permanent Works as shown on the Contractor's Drawings unless otherwise shown on the Employer's Drawings.

2.2.6 Scaffolding and Staging

(a) Scaffolding and staging shall be provided and erected in accordance with the Construction Sites (Safety) Regulations (Cap. 59). In addition, all walkways and elevated working platforms shall have properly constructed kickboards and handrailing.

(b) The use of "bamboo" for scaffolding or staging shall not be permitted without

the prior consent of the Project Manager and if permitted shall be subject to compliance with the requirements of the Construction Site (Safety) Regulations in relation to Scaffold, Working Platforms and Ladders.

2.2.7 Sheet Piling and Trench Support Systems

(a) Sheet piles shall be of the interlocking type and shall be of a suitable class for a particular location.

(b) Sheet piles shall be rolled from mild steel complying BS 4360. Each pile shall

be in one length throughout but where required may be extended by welding an additional length subject to the permission of the Project Manager. Welding shall be in accordance with the requirements of Section 22 of this General Materials and Workmanship Specification.

(c) Holes in the piling for ties and attachment of waling etc. shall be drilled after

driving. Burning of holes shall not be carried out without the permission of the Project Manager.


(d) The sheet piles shall be driven to the line and to the tolerances shown on the Temporary Works drawings and shall be pitched in panels.

(e) Propriety trench support systems shall be reviewed without objection by the

Project Manager prior to use on Site. Propriety systems shall be installed in accordance with the manufacturers recommendations and shall comply with CIRIA Technical Note 95; 1986.

(f) Hard driving for piling works shall not be permitted without the prior consent of

the Project Manager. 2.2.8 Anchors

(a) Where the Contractor proposes to use anchors as part of his Temporary Works he shall, as part of his method statement, submit to the Project Manager for review without objection a detailed specification for the anchors based on the current edition of the Government publication: Geospec 1, Model Specification for Ground Anchors, and shall include in the relevant quality plan a detailed scheme for installation of the anchors. Work shall not commence on Site until the Project Manager has reviewed without objection the Contractor's proposals. Anchors may be subject to the approval of the Building Ordinance Office and/or the Geotechnical Engineering Office and the Contractor must take full cognizance of the time required for the approval procedure in such a case.

(b) As soon as progress of the Works permits, and with the permission of the

Project Manager, temporary ties shall be destressed and as far as is practicable, physically severed from any part of the Works.

2.2.9 Temporary Piling

Piling to Temporary Works shall not adversely affect the geotechnical properties of the strata on which foundations for Permanent Works are to be constructed. Temporary Works piling adjacent to or in the near vicinity of foundations for Permanent Works shall be subject to the review without objection of the Project Manager.

2.2.10 Temporary Decking

(a) Temporary deck panels, unless of concrete construction, shall have an anti-skid surface such as a graded calcined bauxite aggregate bedded in epoxy resin. The skid resistance value of the surface shall be in excess of 45, measured in accordance with BS 3262.

(b) The drainage of the temporary deck shall be such that all the surface water

shall be retained within the plan area of the temporary deck and be discharged properly and effectively through connections to the existing drainage system.

(c) The finished level, falls and camber of the temporary deck shall be in

accordance with the existing roadway. Walkways, which shall be drained properly and effectively, shall be provided to replace existing pavements which are overlapped by the temporary decking. Where walkways are covered they shall be lit for pedestrian safety.


(d) Minimum standard headroom under temporary structures shall be 5.1 m over highways and roadways and 2.3 m over footpaths. Lighting of roadways covered by temporary structures shall be provided in accordance with the requirements for temporary lighting detailed in Section 3 of the General Specification.

2.2.11 Dewatering of Excavations, Drainage and Pumping

(a) The Contractor shall install, operate and maintain all temporary pumping plant and drainage facilities and remove all accumulated silt and debris necessary for the proper execution and completion of the Works.

(b) Groundwater control and drawdown shall be in accordance with the

requirements of Clauses 8E.4.16-8E.4.19 of this General Materials and Workmanship Specification.

2.2.12 Fire Hazard

All materials which present a fire hazard or which may give off noxious fumes in the event of ignition will be rejected for use in the Temporary Works and the Contractor shall immediately remove such materials from Site.

2.2.13 Welding

The Contractor's Equipment used for welding shall be in accordance with the appropriate British Standard and the safety regulations applicable in Hong Kong Construction Safety Regulations. Welding shall be carried out in compliance with Section 22 of this General Materials and Workmanship Specification.


APPENDIX A2.1

TEMPORARY WORKS DESIGN CRITERIA A2.1.1 Preamble This Appendix specifies the criteria which shall be used for the design of Temporary

Works. A2.1.2 Ground Movement (1) The design of the Temporary Works shall investigate, evaluate and define

acceptable limits for ground movement within and around the Site and thereby avoid damage to adjacent property, land footways, roads and utilities.

(2) The installation of any wall (prior to dewatering and excavation) shall not

produce settlement in the adjacent ground or buildings greater than 25 mm. No dewatering will be permitted during the wall installation. In general, dewatering of an excavation will not be permitted until a closed perimeter of impermeable wall is completed.

(3) The Contractor shall establish an adequate number of settlement monitoring

points on both the front and back of adjacent land. Readings at appropriate intervals shall be continued throughout the duration of the Contract. If any of the following criteria are reached, irrespective of whether or not damage has occurred, the Contractor shall notify the Project Manager immediately:

(a) 5 mm - settlement between consecutive readings; (b) angular distortion exceeding 1/1000; or (c) 25 mm - total settlement of any part of a building or other structure. These requirements are in addition to any other requirements which may be

required by the Contract. A2.1.3 Ground Water The ground water level at the Airport may be at or near to ground level and the

effect of ground water must be taken into account in the design of Temporary Works.

A2.1.4 Construction Method The design of Temporary Works shall take full account of the proposed construction

method. The Temporary Works drawings and calculations shall demonstrate the adequacy of the proposed construction method at each construction stage.

A2.1.5 Loads and Forces The design of Temporary Works shall take account of all the applied external forces

and imposed structural deformations.


A2.1.6 Excavation (1) The Temporary Works design shall take into account the temporary condition

when the excavation nears the bottom of permanent or temporary retaining walls. Unless otherwise stated on the Employer's Drawings, the factors of safety against base failure from bottom heave, failure from inward yielding, failure from piping or blows, shall be a minimum value of 1.5.

(2) The design of Temporary Works associated with earthworks, including

temporary slopes, stockpiles and drainage, shall be such that the risk of failure is not more than that which would be adopted if the Temporary Works were to be permanent. Allowance may be made in the design of the Temporary Works for the shorter design life and for the risk to persons and property and the surface water and groundwater conditions which are likely to occur during construction.

A2.1.7 Design Life The design of Temporary Works may take into account the limited duration over

which the Temporary Works are expected to function. Drawings submitted by the Contractor shall make clear where provision for limited life has been taken into account, particularly where this may have an influence on the stability of the Temporary Works.

A2.1.8 Cofferdams and Temporary Retaining Walls (1) The type of cofferdam and retaining wall proposed shall be suitable for the

designed purpose, taking into account the ground and other local conditions. (2) Calculations shall be carried out in accordance with the relevant British

Standards. (a) For loads, the following shall apply : (i) the influence of wind, temperature, settlement, creep and the like

shall be taken into account; (ii) the applied load shall be calculated as accurately as possible; (iii) the most onerous load combination shall be obtained; (iv) the primary load resisting system shall be designed at basic

permissible stress; and (v) the secondary load resisting system may be designed with

permitted overstress. (b) All materials used as load carrying elements shall conform to the

relevant British Standard. The design shall be based on the basic permissible stresses as recommended in the relevant British Standard and the Building (Construction) Regulations (Cap. 123) where appropriate.


(c) Materials not conforming with the relevant British Standard may be used, but only if the yield stress can be established. In this case the basic permissible stresses shall be calculated by applying the same partial safety factor on that yield stress as used in the relevant British Standard.

(3) Where the loading combination can be assessed with confidence,

overstressing to 25% greater than the basic permissible stress may be permitted, except for the most onerous load combination condition or when the excavation is at its lowest level. Overstress may also be allowed for abnormal or extreme load calculations, when calculating the most onerous condition, which have a low probability of concurrent occurrence. For these latter two conditions, overstressing of the primary support system of walling and struts shall not be allowed.

(a) An overstress of 25% greater than the basic permissible stresses may

be allowed on a secondary load resisting system, such as steel sheet piles, provided that a method exists to rectify the system if over deflection or similar signs of distress become apparent.

(b) The following materials and sections in cofferdams may be

overstressed by the amounts stated:

(i) steel sheet piling: 25% increase in allowable bending and shear stresses;

(ii) steel walings: for transient loads a 25% increase in allowable

bending and shear stresses; and (iii) reinforced concrete walings: 25% overstress during the early

stages of excavation and during the installation of frames.

(c) Overstressing shall not be allowed in struts (concrete or steel) or H-piles supporting lateral loads (concrete, steel or timber).

(d) Struts require a factor of safety of 2 against buckling. Calculated strut

loads shall be further increased by the load induced due to a temperature change of 34°C.

(e) Tendons for ground anchors shall not be stressed to greater than 64%

of their nominal failure load.

(4) The design and construction of a cofferdam shall limit ground movement around the Site and avoid damage to adjacent property, roads, footways and utilities.

(a) Settlement of adjoining structures, resulting from lateral deflection of the

waling systems, shall not exceed 25 mm. (b) During dewatering the piezometric pressure in the soil level effectively

supporting the adjacent property shall be maintained. This piezometric pressure may be lowered by a maximum of 2 m.


A2.1.9 Temporary Decks and Pedestrian Bridges (1) The design of temporary decks which are required to carry traffic shall be

carried out by:

(a) using HA highway loading; (b) obtaining the most onerous load combination; and (c) checking with 22.5 units HB highway loading.

Where loads from Contractor's Equipment are likely to exceed these design loads the deck and supporting structure shall be strengthened accordingly.

(2) The design of the temporary decks and support systems shall allow for environmental loads, including temperature difference.

(3) Temporary pedestrian overbridges together with supporting structures shall

be designed for a characteristic load of 5.0 kN/m2. (4) Permissible stresses shall comply with the relevant British Standard and the

Building (Construction) Regulations (Cap. 123) where appropriate. An overstress of 25% shall be allowed when checking the design of temporary road decks using HB loads only.

(5) All other types of temporary decks shall be designed using loading criteria

reviewed without objection by the Project Manager. A2.1.10 Falsework

(1) The design shall demonstrate that it includes full allowance for all dead, environmental (wind and temperature, as appropriate), and applied loads. The latter shall include an allowance for vertical loading on all parts of the falsework, for access and working conditions, which shall not be less than 1.5 kN/m2. Where heavy items of Contractor's Equipment are used or materials stored on the falsework or on the completed structure before it becomes self-supporting, this allowance shall be increased. The drawings shall be clearly marked with the maximum safe limit for loading of the falsework from items of Contractor's Equipment or materials.

(2) The falsework shall be designed to sustain the following horizontal loading,

which may act transversely or longitudinally, separately or simultaneously.

(a) Dynamic pressure head due to a wind speed in accordance with the recommendations stated in the "Code of Practice on Wind Effects, Hong Kong".

(b) Horizontal loads arising from the unintentional non-verticality of vertical

load carrying members.


(c) Horizontal forces derived from impulse and impacts upon or attachments to the falsework, unbalanced horizontal forces derived from the application of vertical loads to non-vertical surfaces, movements of the falsework due to temperature, creep, shrinkage, settlement, post-tensioning operations, external ties and anchorages.

(3) (a) The design of the Temporary Works shall ensure that the falsework

receives the loads from, and maintains in the required position, elements of the Permanent Works until they become self supporting. Facilities shall be provided for compensating for falsework deflections, the order of magnitude of which shall be calculated by the Contractor and reviewed without objection by the Project Manager.

(b) Loads imposed on the permanent structure by the falsework shall be

within the allowable load capacity of the permanent structure. Sufficient load spreading elements shall be used to achieve this as necessary. The design of the falsework shall include calculations to prove that the permanent structure is not overloaded.

(4) Falsework erected in close proximity to traffic or construction vehicles shall

be protected against impact from vehicles by crash barriers. These shall be capable of sustaining a load of a 1.5 tonne vehicle striking the barrier at 110km/hour and at an angle of 20° without permitting the vehicle or barriers to come into contact with any part of the falsework.

(5) Foundations for falsework shall be designed to sustain the calculated

maximum loads without failure or unacceptable settlement. The calculations shall by reference to soil data or tests demonstrate the validity of assumptions made in respect of permissible settlements and earth pressures under falsework foundations.

(6) All materials used as load carrying elements in the falsework shall conform to

the relevant British Standards and the Building (Construction) Regulations (Cap. 123) where appropriate in respect of quality, and the design shall use the basic permissible stresses in those standards. Materials not conforming with the relevant British Standard may be used, but only if the yield stress can be established. In which case the basic permissible stress shall be calculated by applying the same safety factor on that yield stress as used in the relevant British Standard.

(7) A minimum factor of safety of 1.2 is required against instability of the

falsework under any combination of vertical and horizontal load. (8) Testing of materials or components shall be carried out when their quality or

adequacy is in doubt. As far as possible, such tests shall conform to the appropriate British Standards or shall be as stated in the Contract.

(9) Where materials are re-used, the basic permissible stresses shall be reduced

to suit the condition of the material.


A2.1.11 Formwork Formwork shall be designed by the Contractor to withstand the worst combination

of the following without causing bulging or deflection: (1) total weight of reinforcement, live concrete and formwork; (2) construction loading including the dynamic effects of placing and compacting

concrete and construction traffic; and (3) wind loads. A2.1.12 Earthworks Notwithstanding the requirements of Section 7, the design of Temporary Works

associated with earthworks, including temporary slopes, stockpiles and drainage, shall not prejudice the long term integrity or stability of the Permanent Works or present a risk to persons, property, the surface or groundwater conditions.


APPENDIX A2.2

CERTIFICATION OF THE DESIGN OF TEMPORARY WORKS Part 1 (To be signed by a professionally qualified member of the Contractor’s staff, or of his sub-contractor’s staff, responsible for the Contractor’s Design)

Contract No. & Name:

Part of Works Designed:

Drawings as Listed in Attachment 1 (Number of Drawings: no.) Calculations Title:

Prepared by:

Dated: No. of Pages Rev.:

Method Statement Title:

Submission No.: Rev.: Certification I certify that the Temporary Works described above has been designed in accordance with the Contract and that the design and drawings have been checked and found satisfactory by the undersigned.

Signed: Date:

For and on behalf of the Contractor Name and qualifications of signatory:


Part 2 (To be signed by the Checking Engineer) Certification I certify that the Temporary Works described above has been designed using all the skill and care to be expected of a professionally qualified and competent designer experienced in work of a similar nature and scope and that I have checked the design and drawings and found them satisfactory.

Signed: Date: Name and qualifications of the Checking Engineer:

Name of firm or company:

Refer to Attachment 1 (also to be endorsed by Contractor and Checking Engineer)

General Materials and Workmanship Specification 13/14 January 2011 Issue No. 5, Volume 1 – Civil and Structural Works Section 2 – Temporary Works

Attachment 1 to the Certificate of the Design of Temporary Works

Contract No. & Name:

Element of Works Designed:

Drawing No. Rev Title

Signed: Date:

For and on behalf of the Contractor

Signed: Date:

Checking Engineer

General Materials and Workmanship Specification 14/14 January 2011 Issue No. 5, Volume 1 – Civil and Structural Works Section 2 – Temporary Works

APPENDIX A2.3

CERTIFICATION OF LOADING, DISMANTLING OR REMOVAL OF TEMPORARY WORKS

A2.3.1 Loading / Dismantling / Removal * of Temporary Work Part 1 : To be signed by the Temporary Works Co-ordinator. Description of Temporary Works (full description including drawing references, if any): a) I certify that the Temporary Works described above have been constructed in

accordance with the Contractor's Drawings and that they have been checked and found satisfactory for loading by the undersigned.

b) I certify that any structure supported by the falsework described above has been

checked by the undersigned and that it has become self supporting and that the Temporary Works may be dismantled or removed.

[a)/*b)] Date Signed Name [of Temporary Works Co-ordinator] For and on behalf of [Contractor's name] Part 2 : To be signed by the Checking Engineer. a) I certify that the Temporary Works described above have been constructed in

accordance with the Contractor's Drawings and that they have been checked and found satisfactory for loading.

b) I certify that any structure supported by the Temporary Works described above has

become self supporting and that the Temporary Works may be dismantled or removed.

[a)/*b)] Date Signed Print name of Checking Engineer, qualifications, and name of any company he represents * Use only one of the alternatives, as appropriate.

General Materials & Workmanship Specification 1/7 January 2011 Issue No. 5, Volume 1- Civil & Structural Works Section 3 – Site Clearance & Demolition

SECTION 3 SITE CLEARANCE AND DEMOLITION 3.1 GENERAL 3.1.1 General Requirements

The works and materials specified below shall comply with the Sections stated, unless otherwise stated in this Section.

(a) The abandonment of pipes and manholes shall comply with Section 6. (b) Earthworks, shall comply with Section 7.

3.1.2 Methods of Demolition

Use of the following demolition methods will not be permitted;

(a) ‘wrecking ball’; (b) ‘drop ball’; and (c) ‘blasting’.

3.2 RELEVANT CODES AND STANDARDS 3.2.1 Applicable Regulations and Codes

All demolition works shall be carried out in accordance with Building (Demolition Works) Regulations, Code of Practice for Demolition of Buildings, Technical Memorandum for Supervision Plans and Code of Practice for Site Safety Supervision issued by the Buildings Department; approved demolition plans by the Buildings Department, Practice Note for Authorized Persons and Registered Structural Engineers (PNAP) No. 71, all other relevant PNAP and all relevant requirements issued by the HK Government and/or Statutory Authorities.

3.2.2 Employment of Registered Structural Engineer

The Contractor shall appoint a Registered Structural Engineer registered under the Buildings Ordinance for the preparation of demolition method statement, supervision and control of demolition works, scaffolding, shoring and strutting etc.

3.3 SUBMISSIONS 3.3.1 Survey

Areas to be cleared and any structures to be demolished shall be surveyed by the Contractor, and the results submitted to the Project Manager for information, no less than 7 days before demolition starts.


3.3.2 Registered Demolition Contractor and Supervisor

Particulars of the Registered Demolition Contractor, and the Supervisor employed on the demolition works shall be submitted to the Project Manager for review.

3.3.3 Particulars of Operators of Powered Mechanical Plant or Equipment

The personnel particulars, qualifications and experience of the operators of any powered mechanical plant or equipment proposed to be used in demolition works shall be submitted to the Project Manger for review without objection, in a form suitable for onward submission to the Buildings Department for application for consent to commence demolition works.

3.3.4 Particulars of Method of Demolition

Before commencement of demolition works the Contractor shall submit to the Project Manager for review without objection a method statement indicating the following:

(a) proposed method of demolition of each type of structural elements;

(b) sequence of demolition;

(c) method of transporting debris from the upper floors to ground level;

(d) method of raising mobile plant to the roof or upper floors and movement

between floors;

(e) the weight and size of plants used above ground. The support to the floors and other restrictions must be illustrated;

(f) design calculations and drawings showing the maximum debris loadings for all areas and combinations thereof, layout of all necessary falsework or temporary works required for all stages of the works; and

(g) location of all chutes for conveying debris down the building floors, and offsite. 3.3.5 Demolition Waste

A Waste Management Plan shall be prepared in accordance with PNAP 243 and submitted to the Project Manager for review.

3.3.6 Sorting and Disposal of Materials

A method statement for the sorting, processing and disposal of materials arising from or in connection the demolition work shall be prepared in accordance with PNAP 243 and Section 7 of the General Specification and submitted to the Project Manager for review without objection before the commencement of any demolition works.


3.3.7 Site Safety Supervision Plan

The Contractor shall submit to the Project Manager for review without objection, the Site Safety Supervision Plan, prepared in accordance with the Technical Memorandum for Supervision Plan and Code of Practice for Site Safety Supervision of Building Works and Street Works.

3.4 WORKMANSHIP 3.4.1 Existing Services

Before commencement of demolition works the Contractor shall:

(a) locate and identify the position of existing services and utilities affected by the works; and

(b) arrange with the relevant Authorities for the disconnections or diversion of all services and utilities and the removal of all associated fittings and equipment.

3.4.2 Trees

(a) The roots of trees and shrubs which have been cut down shall be grubbed up. Branches shall not be removed from trees which are to be retained unless permitted by the Project Manager; if permitted, the branches shall be removed in accordance with BS 3998 and the cut surfaces shall be treated with a wound sealant.

(b) In respect of existing trees and woodland the Contractor shall ensure for the

duration of the Contract, the following:

(i) there is no unnecessary intrusion into areas of woodland or scrubland;

(ii) the limits of site clearance shall be reviewed without objection by the Project Manager on Site before site clearance commences. All trees to be cleared shall be marked by the Contractor and reviewed without objection by the Project Manager before felling;

(iii) trees not required to be trimmed, pruned or felled shall not be marked;

(iv) nails or other fixings shall not be driven into trees;

(v) fencing or signs shall not be attached or painted on trees;

(vi) trees shall not be used as anchors for ropes or chains used in guying,

pulling and the like; and

(vii) fires shall not be lit under or in the close proximity of trees.

(c) As soon as the Site or any part thereof becomes available the Contractor shall erect temporary protective fencing reviewed without objection by the Project Manager around any tree and group of trees which are required to be protected. The fence shall not be closer than 2 m from the trunk of any such tree and all such work shall be executed using only hand-held tools.


3.4.3 Stripping Topsoil

At the commencement of any excavation and prior to any filling the Contractor shall strip any humus topsoil capable of being used as soil conditioner and set it aside for subsequent use in the Works. Any topsoil surplus to the requirement of the Works shall be disposed of in accordance with Clause 7.5.9. Temporary stockpiles of topsoil shall not exceed 2 m in height.

3.4.4 Precautionary Measures

Demolition works shall not commence until all the required precautionary measures have been installed in accordance with Building (Demolition Works) Regulations, Code of Practice for Demolition Works, Technical Memorandum for Supervision Plans and Code of Practice for Site Safety Supervision issued by the Buildings Department; approved demolition plans by the Buildings Department, PNAP 71, all other relevant PNAP and all other relevant requirements issued by the HK Government and/or Statutory Authorities.

3.4.5 Prevention of Overloading

The Contractor shall;

(a) not overload the structure under demolition with demolition plant and/or resulting debris;

(b) comply with the propping requirements or temporary propping system during the operation of mechanical plant on suspension floor as stipulated in the Code of Practice for Demolition of Buildings;

(c) provide all temporary shoring, strutting and/or propping required;

(d) secure and wedge tight top and bottom supports to props. The props shall be braced to provide lateral restraints in at least 2 directions;

(e) not allow mobile equipment to move to within 2 m of the building edge, 1 m of any floor opening or on to any cantilevered structures; and

(f) provide adequate spreaders for props bearing on ground, where necessary, to avoid any undue settlement;

3.4.6 Warning Signs

The Contractor shall erect warning signs in prominent positions indicating demolition works are in progress in both Chinese and English.

3.4.7 Overhead Wires

The Contractor shall prevent damage to overhead wires during demolition operations.

3.4.8 Risk of Fire Explosion

The Contractor shall take precautions to prevent fire or explosion from gas or vapour release, electricity or any other source, especially when removing tanks or pipes which may have contained flammable liquids or gases.


3.4.9 Weatherproofing Retained Areas of Partially Demolished Buildings

(a) Where partially demolished buildings or structures are to be retained the Contractor shall protect the retained building structure and interiors exposed during the course of demolition works with a temporary weather-tight screen erected 1000 mm back from the perimeter edge of floors.

(b) Screens shall be constructed with close boarding fixed to framing and faced

outside with roofing felt of a type reviewed without objection. The exposed floor beyond the screening shall be covered with roofing felt of similar type to that used to face screens and a waterproof seal formed between floor and screen. Doors in the screens shall be constructed and fixed with secure fastenings and hanging devices as necessary to provide authorised access.

3.4.10 Partly Demolished Structures

The Contractor shall leave the Site and partly demolished structures in a safe condition at the end of each day’s work. No accumulation of debris shall be allowed, particularly at working floors and at ground floor, which causes excessive pressure on the floors, slopes, retaining structures, hoardings/covered walkways, catchfans and walls of adjoining structures.

3.4.11 Care of Electric Cables

The Contractor shall take every precaution to prevent damage and to exercise extreme care during execution of the work in the vicinity of live electrical cables.

3.4.12 Disused Drains

The Contractor shall disconnect and seal off all storm water drains or sewers from the last manhole to the Government storm water drain or sewer in accordance with the requirements of the Relevant Authorities.

3.4.13 Burning

The Contractor shall not burn any rubbish or materials arising from the demolition on Site.

3.4.14 Spoil Heaps

(a) The Contractor shall prevent excessive lateral pressure due to stockpiling of debris against walls, adjoining structures and steel hoardings adjoining the public footpaths or carriageways.

(b) Spoil heaps shall be not be placed on catch platforms or on top of covered

walkways. Spoil heaps shall be cleared away immediately to prevent overloading any part of the existing structure.

3.4.15 Reinstatement

(a) Areas affected by Site clearance shall be reinstated as follows:

(i) Fine fill material shall be deposited and compacted in voids which are

left in the ground.

(ii) Holes which are left in structures and pavements shall be made good using material similar to the material in the adjoining area.


(iii) The ends of fences, walls, structures, utilities and other items shall be

made good in such a manner that the affected parts will not corrode or deteriorate, and will remain stable.

(iv) Straining posts shall be fixed at the end of strained fences which have

been cut and the fences shall be restrained. 3.4.16 Materials and Equipment for Re-use and Storage

(a) Items to be re-used or taken to store shall be dismantled and removed by a

suitable method so as to avoid or minimise damage. The items shall be cleaned before taking to store.

(b) Items to be re-used in the Works shall be kept in stores provided by the

Contractor. (c) Items which are to be taken to the Employer's store shall be delivered by the

Contractor. (d) Materials or equipment which are to be reused or taken to store and which are

damaged due to the Contractor’s negligence shall be repaired by the Contractor by a method reviewed without objection by the Project Manager. Materials or equipment which are lost or which are not capable of being repaired satisfactorily shall be replaced by the Contractor. Except for items which are to be re-used or taken to store, demolished items, trees, shrubs, vegetation, boulders, debris, rubbish and other items arising from site clearance shall be disposed of by the Contractor and shall become the property of the Contractor when they are removed from the Site.

(e) All construction and demolition materials arising from or in connection with the

demolition work shall be sorted on-Site and separated into different groups for disposal at landfills, public filling areas, in filling areas provided by the Contractor, or recycling as appropriate.

(f) Unless otherwise stated in the Contract, all construction and demolition

materials arising from or in connection the demolition work shall become the property of the Contractor. The Contractor shall promptly remove all sorted and processed materials arising from or in connection with the demolition work from the Site on a regular basis as demolition work proceeds.

3.4.17 Remove debris

(a) All construction and demolition materials arising from or in connection with the

demolition work shall be sorted on-Site and separated into different groups for disposal at landfills, public filling areas, in filling areas provided by the Contractor, or recycling as appropriate.

(b) Unless otherwise stated in the Contract, all construction and demolition

materials arising from or in connection the demolition work shall become the property of the Contractor. The Contractor shall promptly remove all sorted and processed materials arising from or in connection with the demolition work from the Site on a regular basis as demolition work proceeds.


3.5 INSPECTION 3.5.1 Joint Inspections

Prior to the commencement of site clearance and demolition, and after completion, the Contractor shall undertake joint inspections with the Project Manager of all existing structures to be retained within the Site and produce a Condition Survey Report submitted to the Project Manager for review. Any damage noted to the structures during the second inspection shall be made good by the Contractor to the satisfaction of the Project Manager. Photographic records, taken by the Contractor and reviewed without objection by the Project Manager, shall be kept as part of the joint inspection.

General Materials & Workmanship Specification 1/20 January 2011 Issue No. 5, Volume 1 - Civil & Structural Works Section 4 – Landscaping Works

SECTION 4 LANDSCAPING WORKS 4.1. GENERAL 4.1.1 General Requirements

The works and materials specified below shall comply with the Sections stated, unless otherwise stated in this Section. (a) Site clearance shall comply with Section 3. (b) Earthworks shall comply with Section 7. (c) Landscape hardworks shall comply with Section 11. (d) Geotechnical works shall comply with Section 8.

4.1.2 Weather and Ground Conditions

Soiling, cultivation, planting and other similar landscape softworks and establishment works operations shall not be carried out at times when weather or ground conditions may adversely affect the Permanent Works.

4.1.3 Use of Chemicals

Chemicals shall not be used for landscape softworks and establishment works except with the permission of the Project Manager. Chemicals shall be used, stored, mixed and applied in accordance with the manufacturer's recommendations. Containers for chemicals shall be disposed of off-Site by methods reviewed without objection by the Project Manager.

4.2. DEFINITIONS AND ABBREVIATIONS 4.2.1 Landscape Softworks

Landscape softworks are all works of a horticultural nature, and shall include the placing, cultivation and preparation of topsoil and subsoil layers, and the supply and planting of trees, shrubs and other plant material, and any associated works.

4.2.2 Landscape Hardworks

Landscape hardworks shall include the paving, tree grilles, tree guards and tree rings and any other items stated as such in the Contract.

4.2.3 Establishment and Landscape Works

(a) Establishment works shall include the regular inspections, cultivation, watering, fertilizing and other operations specified to be performed during the period stated in the Contract for such inspections and operations.

(b) Landscape works means landscape softworks, landscape handworks and

establishment works.


4.3. RELEVANT CODES AND STANDARDS 4.3.1 British Standards Relevant to Landscape Softworks and Establishment

Works

A list of British Standards publications relevant to landscape softworks and establishment works is included as Appendix A4.1. Works shall comply with these standards.

4.4. MATERIALS 4.4.1 Seedling Trees

Seedling trees shall have the following characteristics: (a) less than 2 years old; (b) single slender stem; (c) well developed vigorous root system; (d) height above soil level of between 150 mm and 900 mm; and (e) grown in a container at least 50 mm diameter and 150 mm deep.

4.4.2 Whip Trees

Whip trees shall have the following characteristics: (a) less than 3 years old; (b) single central stem well furnished with side branches according to species; (c) well developed vigorous root system; (d) height above soil level of between 900 mm and 2000 mm; and (e) grown in a container at least 75 mm diameter and 150 mm deep.

4.4.3 Light Standard Trees

Light standard trees shall have the following characteristics: (a) sturdy straight stem at least 1500 mm high from soil level to the lowest

branch; (b) stem diameter of between 20 mm and 25 mm measured at a height of 1 m

from soil level; (c) according to species, either a well balanced branching head or a well defined

straight and upright leader with branches growing out from the stem with reasonable symmetry;


(d) total height above soil level of between 2000 mm and 3000 mm; and (e) rootball at least 300 mm diameter and 250 mm deep.

4.4.4 Standard Trees

Standard trees shall have the following characteristics : (a) sturdy straight stem at least 1800 mm high from soil level to the lowest

branch; (b) stem diameter of between 25 mm and 50 mm measured at a height of 1 m



(d) total height above soil level of between 2750 mm and 3500 mm; and (e) rootball at least 350 mm diameter and 300 mm deep.

4.4.5 Heavy Standard Trees

Heavy standard trees shall have the following characteristics : (a) sturdy, straight stem at least 2100 mm high between the soil level and the

lowest branch; (b) stem diameter of between 50 mm and 100 mm measured at a height of 1 m



(d) total height above soil level exceeding 3500 mm; and (e) rootball at least 400 mm diameter and 350 mm deep.

4.4.6 Small Shrubs

Small shrubs shall have the following characteristics : (a) at least two one-year old vigorous stems arising at or near the base; (b) well developed, vigorous root system; (c) according to species, height above soil level not less than the height stated in

the Contract; and (d) grown and supplied in a container at least 75 mm diameter and 125 mm deep.


4.4.7 Large Shrubs

Large shrubs shall have the following characteristics : (a) bush with at least three one-year old vigorous stems arising at or near the

base, with an overall diameter equal to 2/3 of the height; (b) well developed vigorous root system; (c) according to species height above soil level not less than the height stated in

the Contract; and (d) grown and supplied in a container at least 100 mm diameter and 125 mm

deep. 4.4.8 Conifers

Conifers shall have the following characteristics : (a) well developed stem well furnished with leaf or needle bearing side shoots; (b) well developed vigorous root system; (c) size not less than that stated in the Contract; and (d) grown and supplied in a container with dimensions not less than the dimensions stated in the Contract.

4.4.9 Palms

Palms shall have the following characteristics: (a) well developed upright habit with a well balanced, symmetrical head;

(b) well developed vigorous root system; (c) for single stem species, height above soil level to the growth point not less

than the height stated in the Contract; (d) for multi-stemmed species, height above soil level to the growth point not less

than the overall height stated in the Contract; and (e) rootball or grown and supplied in a container at least 300 mm diameter and

300 mm deep. 4.4.10 Bamboo

Bamboo shall have the following characteristics :

(a) well developed vigorous root system;

(b) for single stem species, a single shoot or trunk with height above soil level not less than the height stated in the Contract;


(c) for multi-stemmed species, a clump of at least three stems with height above soil level not less than the height stated in the Contract; and

(d) rootball or grown and supplied in a container at least 200 mm diameter and 200 mm deep.

4.4.11 Herbaceous Plants

Herbaceous plants shall have the following characteristics : (a) well developed vigorous shoots; (b) a well developed vigorous root system; (c) height above soil level or diameter of plant for clumps not less than the height or diameter stated in the Contract; and (d) healthy well developed bulbs, corms, rhizomes or tubers.

4.4.12 Containerised Plants

Containerised plants shall be grown in open ground and then lifted and placed in a rigid or semi-rigid container. Plants shall be left to grow in the containers for at least 3 months before being delivered to Site. The dimensions of containers shall not be less than the relevant rootball or container dimensions stated in Clauses 4.4.1 to 4.4.10.

4.4.13 Grass Seed

(a) Grass seed shall be supplied true to species and variety and shall not contain impurities except as stated in Clause 4.6.13(b). Containers shall be labeled with the origin of all seed contained therein and the name of the supplier.

(b) The quality of grass seed shall be gauged by purity, germination percentage

and freedom from weeds. The total weed seed content shall not exceed 0.5% by mass and the total content of other crop seeds shall not exceed 1% by mass.

4.4.14 Turf

(a) First quality turf shall consist of 75%-85% axonopus compressus and 15%-25% cynodon dactylon and other stoloniferous species unless otherwise stated in the Contract.

(b) The grass shall be of even density, forming a turf which is sufficiently fibrous

to hold together when handled. The grass shall be free from pest or disease. Turf shall consist of sods with soil and roots.

4.4.15 Sprigs

Sprigs shall consist of axonopus compressus, cynodon dactylon, paspalum distichum and other stoloniferous grasses. Axonopus compressus shall not be used on slopes exceeding 15° to the horizontal. Sprigs shall be at least 100 mm long.


4.4.16 Soil-mix

Soil-mix shall consist of friable, completely decomposed granite and soil conditioner in the proportions 3 : 1 by volume. Soil-mix shall be free from grass or weed growth, sticky clays, salt, stones exceeding 50 mm diameter, the materials stated in Clause 7.2.1(b) and other deleterious material.

4.4.17 Soil Conditioner

(a) Soil conditioner shall be organic material and shall be free from impurities and substances injurious to plants. Soil conditioner shall have the following properties :

(i) the pH value shall be between 5.0 and 7.5; (ii) the moisture content measured in accordance with Clause 7.5.11(b)

shall be between 30% and 50%; (iii) the consistency shall be fine and freely flowing; and (iv) the carbon/nitrogen ratio shall be between 25 and 70.

(b) Soil conditioner shall be peat moss or properly composted organic material.

Composted organic material shall be stable and shall not be liable to decompose further generating heat.

4.4.18 Mulch

Mulch shall be a composted organic material either as stated in Clause 4.4.17 for soil conditioner or granulated tree bark or wood shavings. The properties of mulch shall be as stated in Clause 4.4.17 for soil conditioner except that the consistency shall be coarser to avoid being blown away by wind.

4.4.19 Mulch for Hydroseeding

Mulch for hydroseeding shall be a proprietary type manufactured from cellulose or paper based materials and reviewed without objection by the Project Manager.

4.4.20 Fertilizer

(a) Pre-planting fertilizer shall be provided in the ratio of 15:9:15:2 (nitrogen / phosphorus / potassium / magnesium) slow release granular fertilizer.

(b) Post-planting fertilizer shall be 12:12:17 (nitrogen/phosphorus/potassium)

granular fertilizer.

(c) Hydroseeding fertilizer shall be 15:15:15 (nitrogen/phosphorus/potassium).

(d) Phosphate fertilizer shall be triple superphosphate powder.

(e) Fertilizer shall be supplied in sealed waterproof bags.


4.4.21 Soil Binder

Soil binder shall be a proprietary type reviewed without objection by the Project Manager and shall consist of a binding medium applied in aqueous suspension by spraying onto the surface of the soil to stabilise and condition the soil. The binding agent shall not be injurious to plant growth.

4.4.22 Stakes, Ties and Guys

(a) Steel stakes for heavy standard trees shall be 25 mm x 25 mm x 4 mm or 40 mm x 40 mm x 4 mm angle iron and shall have the appropriate lengths stated in Clauses 4.6.3(d), 4.6.3(h)(ii) and 4.6.3(i)(ii); steel stakes shall have all sharp edges removed to avoid damage to the tree.

(b) Ties shall be rot-proof rope or straps fitted with plastic, bamboo or other spacers and a protective sleeve to fit around the plant; ties shall be capable of adjustment after fixing.

(c) Guys shall be a multi-strand twisted galvanized steel wire of between 4 mm and 6 mm diameter. Each guy shall be fitted with a flexible rubber or plastic sleeve to prevent chafing, rubbing or abrasion of the plant, and a turnbuckle for adjustment.

4.4.23 Protective Fabric Material

Protective fabric material for hydroseeding shall be a proprietary type of degradable fabric reviewed without objection by the Project Manager. The fabric shall not degrade within 100 days after application or until the specified grass cover has been established.

4.5. SUBMISSIONS 4.5.1 Particulars of Seed Mixture, Turf, Sprigs, Soil Conditioner and Water

(a) The following particulars of the proposed materials for landscape softworks and establishment works shall be submitted to the Project Manager for review without objection:

(i) origin of trees, shrubs, turves, sprigs and other plant material; (ii) details of nurseries;

(iii) a certificate or a numbered seed analysis report for each seed mixture

issued within 6 months before the date of use of the seed showing the species and variety of the seed, the date of testing and including results of tests for; • percentage germination of pure seed in a fixed time under standard

laboratory conditions; and • percentage composition by weight, including details of impurities;


(iv) a certificate of analysis for soil conditioner including details of the composition and results of tests for; • pH value; • moisture content; and • carbon/nitrogen ratio; and

(v) source of water for watering.

4.5.2 Particulars of Hydroseeding

(a) The following particulars of the proposed materials and methods for hydroseeding shall be submitted to the Project Manager for review without objection:

(i) species and rate of application of grass seed; (ii) type and rate of application of fertilizer, mulch and soil binder; (iii) type and colour of dye; (iv) type of protective fabric material;

(v) details of the company employed to carry out the hydroseeding and the

equipment to be used; and

(vi) manufacturer and details of mulch for hydroseeding. 4.5.3 Representative Samples of Materials

(a) Representative samples of the following proposed materials shall be submitted to the Project Manager at the same time as particulars of the material are submitted:

(i) each seed mixture;

(ii) turf;

(iii) sprigs; and

(iv) soil-mix.

(b) Representative samples of materials for landscape works and establishment

works shall be made available for inspection by the Project Manager, at nurseries and other sources before the materials are delivered to the Site.

(c) A certificate of purity of the grass seed to be used in the Works shall be

submitted to the Project Manager. The batch number of the certificate shall be checked against that on the bag. The certificate shall not be more than 6 months operations, a 500 g seed sample shall be supplied and retained under refrigeration by the Project Manager until the viability of the seed is proven or disproven on Site. Impurities in the seed mix such as stores, soil, twigs and other foreign matter shall not be accepted.


(d) Before any turf is delivered to the Site, the Contractor shall provide a sample of at least 4 m2 from the source for review without objection by the Project Manager.

4.6. WORKMANSHIP 4.6.1 Handling, Storage and Transport

(a) Handling and storage of rootballed stock:

Plants grown in open ground shall be well watered before lifting and shall be lifted in such a manner that the specified rootball is obtained with minimum disturbance to the roots. The rootball shall be securely wrapped immediately after lifting to prevent loss of soil and moisture using hessian or straw. The wrapping material shall not be removed until the plant is required for planting.

(b) Handling and storage of container grown and containerised stock:

Container grown and containerised stock shall be well watered before despatch from the nursery and shall remain in the containers until required for planting.

(c) Transport of plants:

Plants shall be wrapped and protected to prevent mechanical damage during lifting and transportation. The trunk from soil level to the lower branches of trees in the light standard, standard and heavy standard categories shall be securely wrapped to prevent moisture loss using hessian or straw. All plants which are to be removed while in leaf shall be covered with tarpaulins during transport to reduce excessive transpiration.

(d) Storage of plants:

(i) Plants shall be protected from exposure to conditions which may affect the plant adversely.

(ii) Plants shall be protected from damage and damaged plants shall not be

used in the Permanent Works unless permitted by the Project Manager. If the Project Manager permits damaged plants to be used, damaged material shall be pruned and wounds shall be dressed as stated in Clause 4.6.5(g).

(e) Storage of trees and shrubs:

Trees and shrubs which are not immediately planted in their permanent positions shall be supported upright on level ground, regularly watered and maintained in good condition.

(f) Handling and storage of turf and sprigs:

Turf and sprigs shall not be lifted when waterlogged or very dry and shall be packed to avoid drying out. Turf and sprigs shall be stored by spreading out and shall not be stacked. Turf and sprigs shall be kept moist and in good condition and shall be delivered and laid within 72 hours of lifting.


(g) Storage of grass seed:

Grass seed shall be stored in bags off the ground in a clean, dry, well ventilated location free from vermin. Prolonged storage shall be carried out under controlled conditions of temperature and humidity.

(h) Storage of fertilizer:

Fertilizer shall be stored off the ground in sealed waterproof bags and shall be protected from exposure to conditions which may adversely affect the fertilizer.

4.6.2 Pre-planting Works

(a) Preparatory works:

Before soiling or planting for landscape softworks and establishment works starts, preparatory works shall be carried out by one or more of the treatments stated in Clauses 4.6.2(b) to 4.6.2(i), as appropriate or as stated elsewhere in the Contract.

(b) Cleaning ground:

Weeds, rubbish, litter, stones exceeding 50 mm diameter and all deleterious material shall be removed from the surface of the ground. Vegetation shall be cleared without using herbicide unless permitted by the Project Manager. If permitted, the herbicide shall be a proprietary type reviewed without objection by the Project Manager and shall be applied in accordance with the manufacturer's recommendations.

(c) Ripping:

The ground shall be ripped by drawing a tine through the soil to a depth of 300 mm at 500 mm centres. All obstructions to cultivation or deleterious material brought to the surface shall be removed and voids left by the ripping operation shall be filled with soil of the same type as existing. Ground at a slope exceeding 15° to the horizontal shall not be ripped.

(d) Contaminated ground:

Ground which is contaminated by oil, chemicals or other substances which may affect plant growth adversely shall be excavated to 300 mm below the contaminated depth and beyond the extent of the contamination. Voids left by excavation shall be filled with uncontaminated soil of the same type as existing.

(e) Soiling:

Soil-mix shall be spread and levelled to the depth stated in the Contract. The depth of uncompacted soil-mix shall be sufficient to allow the level of the area to comply with finished levels after natural settlement has taken place. The finished level of soil-mix over areas to be grassed shall be 25 mm above adjacent kerbs, paving, covers, frames and other hardware.


(f) Cultivation:

(i) Cultivation shall be carried out to a minimum depth of 150 mm or as stated in the Contract. Pre-planting fertilizer and soil conditioner shall be spread to a thickness of 50 mm over the surface before cultivation.

(ii) Stones exceeding 50 mm diameter shall be removed from the surface of

the soil after cultivation.

(g) Scarifying:

Scarifying shall be carried out by loosening the soil to a depth of between 10 mm and 20 mm using a pronged implement such as a rake but without turning the soil.

(h) Protection of prepared ground:

(i) Prepared ground shall be protected from compaction, erosion and siltation and shall not be used by Contractor's Equipment, other vehicles or pedestrian traffic.

(ii) Prepared ground which becomes compacted, eroded, silted up or

damaged shall be replaced or dealt with by methods reviewed without objection by the Project Manager.

(i) Removal of material:

Weeds, rubbish, litter, stones exceeding 50 mm diameter and deleterious material removed during ground preparation shall be disposed of by the Contractor by methods reviewed without objection by the Project Manager.

4.6.3 Planting

(a) General:

Planting shall be carried out between 1st March and 30th September unless otherwise specified in the Contract.

(b) Use of excavated material:

Material excavated from planting pits which complies with the specified requirements for decomposed granite shall be used for soil-mix. Material excavated from planting pits which does not comply with the specified requirements for decomposed granite shall be disposed of by the Contractor and shall be replaced by material which complies with the specified requirements for decomposed granite.

(c) Planting:

(i) Plants shall be well watered several hours before planting; the soil in the

container or rootball shall be moist and cohesive. Containers or rootball wrapping shall not be removed until the time of planting and the rootball shall not be disturbed by loosening or breaking.


(ii) Each plant shall be placed upright in the pit and set at the same level as planted in the nursery or container.

(iii) Soil-mix shall be deposited and compacted in layers around the rootball

until level with the surrounding ground in such manner that the rootball is not disturbed. Plant shall be well watered to soak the rootball and soil-mix immediately after planting.

(d) Staking, tying and guying:

(i) Stakes shall be driven into the ground after the pit has been excavated

and before planting in such a manner that the rootball and aerial parts of the plant are not damaged. The stake shall be secure after driving and shall be higher than 70% of the overall height of the plant.

(ii) Guys and sleeves shall be fixed to prevent chafing, rubbing and

abrasion of the plant and shall be secured to a well driven steel stake or other anchor. Each plant shall be fitted with three guys secured at a point not higher than 60% of the overall height of the plant. Turnbuckles shall be adjusted as necessary after planting.

(iii) Bamboo stakes shall be used in locations stated in the Contract.

Bamboo stakes shall be securely tied with "scaffold tie" to form a tripod not exceeding 60% of the overall height of the plant.

(e) Mulching:

After planting and watering, mulch shall be spread to a consolidated thickness of at least 50 mm on areas of bare ground as stated in the Contract.

(f) Notch planting of seedlings:

Notch planting of seedlings shall be carried out by forming a notch making two cuts at approximately 90° using a hand held pick or spade with the apex pointing up any slope; the notch shall be sufficiently deep to accommodate the root system of the seedling. The notch shall be opened on the second cut to receive the plant and shall then be pushed firmly back into place.

(g) Pit planting of seedlings, shrubs, whips and herbaceous plants:

(i) The size of pits for seedlings, shrubs, whips and herbaceous plants shall be 100 mm greater than the rootball or container diameter and 50 mm deeper than the rootball or container. 50g of pre-planting fertilizer shall be mixed into the soil-mix.

(ii) Whips which require staking shall be secured using one 2 m long stake

and one tie.


(h) Pit planting of light standard and standard trees:

(i) The size of pits for light standard trees and standard trees shall be 200 mm greater than the rootball or container diameter and 100 mm deeper than the rootball or container. The bottom of the pit shall be broken up to a depth of 150 mm. 150 g of pre-planting fertilizer shall be mixed into the soil-mix.

(ii) Each tree shall be secured using two 2.5 m long steel stakes and two

ties. (i) Pit planting of heavy standard trees:

(i) The size of pits for heavy standard trees shall be 300 mm greater than

the rootball or container diameter and 150 mm deeper than the rootball or container. The bottom of the pit shall be broken up to a depth of 150 mm. 250 g of pre-planting fertilizer shall be mixed into the soil-mix.

(ii) Each tree shall be secured using two 3 m long steel stakes and two ties.

Trees exceeding 4 m overall height shall be guyed.

(j) Pit planting of bamboos and palms:

Bamboos and palms shall be planted in accordance with the following :

(i) height not exceeding 2000 mm : Clause 4.6.3(g)

(ii) height exceeding 2000 mm and not exceeding 2500 mm : Clause 4.6.3(h)

(iii) height exceeding 2500 mm : Clause 4.6.3(i)

(k) Pit planting on slopes:

Pits excavated for planting on or adjacent to slopes shall not be left open during wet weather.

4.6.4 Grassing

(a) Hydroseeding:

Hydroseeding shall be carried out between 1st March and 30th September unless otherwise specified in the Contract.

(b) Hydroseeding cover:

Hydroseeding shall achieve a cover by grass species of at least 90% of the surface area of each 10 m² of the area to be hydroseeded within 100 days after the area has been hydroseeded. The grass cover shall be healthy, vigorous and free from perennials and other weeds. The method of determining the cover shall be as stated in Clauses 4.7.1(a) to 4.7.1(g).


(c) Surface conditions for hydroseeding:

The surface to be hydroseeded shall be finished to a coarse open textured surface and shall not be smooth or glazed. Finishing work on slopes by machines shall be carried out across the slope. Vehicle track marks and bucket teeth marks shall not be left parallel to the line of maximum gradient of the slope.

(d) Application of hydroseeding:

(i) Hydroseeding shall be carried out using a proprietary type of

hydroseeding equipment reviewed without objection by the Project Manager.

(ii) Materials for hydroseeding shall be well mixed on the Site in the

hydroseeding equipment immediately before spraying. Seed shall not be damaged from the hydroseeding process.

(iii) Soil binders shall be applied at the rate recommended by the

manufacturer, modified as necessary to suit conditions in Hong Kong. Dye shall be used to demonstrate that adequate cover has been achieved, unless in the opinion of the Project Manager runoff or water courses will be coloured to an unacceptable level.

(iv) The hydroseeding mixture shall be constantly agitated during spraying

to keep it homogeneous and avoid blockage to pipes. Measures shall be taken during application to ensure that material is not lost due to runoff.

(v) Walking on areas that have been hydroseeded shall be restricted to

access for fixing protective material and for patching up.

(e) Protective material:

Areas which have been hydroseeded shall be covered with protective material within 2 days after hydroseeding. The material shall be spiked or stapled to the soil surface with a minimum of 150 mm overlap.

(f) Patching up:

(i) Immediately after germination and a general greening of the

hydroseeded area is apparent, areas where germination has been unsuccessful shall be resprayed. Areas affected by repairs to washout and gullies and other erosion on slopes shall be resprayed.

(ii) Areas which in the opinion of the Project Manager are not accessible or

are too small for the use of a hydroseeder shall be patched up by broadcasting seed. The area shall be lightly scarified with a rake or similar implement and the seed and fertilizer shall be broadcast over the area at a rate of not less than 75 g/m². The seed shall be covered by lightly working into the surface or by spreading sufficient soil to just cover the seed. Broadcast seeding shall be carried out using Bermuda grass (cynodon dactylon) perennial ryegrass (lolium perenne) or carpet grass (axonopus compressus).


(g) Post-planting fertilizer:

Post-planting fertilizer shall be applied between 2 months and 9 months after application of hydroseed and shall be applied between 1st March and 30th September.

(h) Turfing:

(i) Turf shall not be laid on slopes exceeding 15° to the horizontal.

(ii) The area to be turfed shall be cultivated by applying pre-planting

fertilizer at a uniform rate of 40 g/m² and shall then be raked and consolidated to the required level. The finished level after turfing shall be 25 mm above adjacent kerbs, paving, covers, frames and other hardware.

(iii) The turves shall be laid on the prepared soil and shall be firmed into

position using wooden beaters; the beaters shall be frequently scraped clean of accumulated soil or mud. A top dressing of soil-mix shall be applied and well worked into joints and spaces. Irregularities in finished levels due to variation in turf thickness or uneven consolidation of the soil shall be adjusted.

(iv) Turfed areas shall be watered immediately after turf has been laid and

as often as is necessary to ensure establishment. If shrinkage occurs and the joints open, soil-mix shall be worked in and well watered.

(i) Sprigging:

(i) Sprigging shall not be used on slopes exceeding 45° to the horizontal.

(ii) The area to be sprigged shall be scarified before sprigging and sprigs

shall be evenly spread over the area at approximately 50 mm centres. The area shall be topdressed with soil-mix to just cover the sprigs and pre-planting fertilizer shall be applied at a uniform rate of 40 g/m².

(j) Completion of turfing and sprigging:

(i) Turfing and sprigging shall be considered to be complete when the

first flush of growth achieves 90% cover. The method of determining the cover shall be as stated in Clauses 4.7.1(a) to 4.7.1(g).

(ii) Bare patches or areas which fail to become established shall be returfed

or resprigged to maintain 90% cover throughout the establishment period. Areas affected by repairs to washouts and gullies and other erosion shall be returfed or resprigged.


4.6.5 Establishment Works

(a) Establishment works:

(i) The establishment period shall be 12 months. During the establishment period, the Contractor shall carry out regular inspections and cultivating operations to ensure that all grass, trees and other plants thrive and become established. The Contractor shall keep the Site neat and tidy at all times. Inspections with the Project Manager shall be carried out on a monthly basis. The Contractor shall report to the Project Manager before and after carrying out any establishment works and the associated records shall be submitted in duplicate to and of a style reviewed without objection by the Project Manager. The forms shall be countersigned by the Project Manager.

(ii) All necessary measures shall be taken to ensure that grass, trees and

other plants become established and to keep the landscape softworks neat and tidy and free from litter and rubbish.

(b) Replacement of plants and grass:

(i) Plant which are dead, dying or otherwise unsatisfactory shall be

replaced. Replacement planting shall be carried out in season as stated in Clause 4.6.3(a)(ii) using plant material of a similar size to that already established. Measures shall be taken to ensure satisfactory establishment of the replacement plants before the end of the period for establishment works.

(ii) 90% cover of the grass area shall be maintained throughout the period for establishment works and the grass shall provide effective cover of 90% of the area at the end of the period for establishment works. The grass shall be healthy, vigorous and free from perennials and other weeds. Areas which do not comply with this requirements of the Contract shall be reseeded by hydroseeding or broadcast seeding as stated in Clause 4.6.4(f)(ii) or returfed as stated in Clause 4.6.4(h) or sprigged as stated in Clause 4.6.4(i). Measures shall be taken to ensure satisfactory establishment of the replacement grass or turf before the end of the period for establishment works.

(c) Security of stakes and ties:

The Contractor shall be responsible for the security of stakes and ties throughout the establishment period. An inspection of stakes and ties shall be carried out each month by the Contractor; broken, damaged and other unsatisfactory stakes and ties shall be replaced and ties which are causing chafing or abrasion of the plant shall be adjusted.

(d) Firming up plants:

Plants which become loose as a result of wind, rock or other causes shall be firmed up.


(e) Watering:

(i) Fresh water shall be used for watering landscape softworks. Water shall be applied using a rose or sprinkler of a type reviewed without objection by the Project Manager and in such a manner that compaction, washout of soil or loosening of plants will not be caused; any damage caused shall be made good immediately.

(ii) All planted areas shall be watered to ensure successful establishment of

the plant. Any plant reaching permanent wilting point shall be watered immediately.

(iii) An inspection to determine water requirements shall be made in dry

weather by the Contractor and the Project Manager twice weekly.

(iv) The Contractor shall complete watering operations within 24 hours of an instruction from the Project Manager.

(f) Weeding:

(i) All grassed and planted areas shall be kept free from weeds throughout

the period for establishment works.

(ii) Weeding shall be carried out by hand or by mechanical methods reviewed without objection by the Project Manager provided in all cases that no damage to the grass and planted areas will be caused. All weeds, litter and other rubbish resulting from the weeding operation shall be disposed of by the Contractor.

(iii) Planted areas in bare ground shall be weeded to remove all unwanted vegetative growth including aerial parts and roots, over the complete area. Planted areas other than in bare ground shall be weeded to remove all competing and overhanging vegetative growth by cutting the growth down to not more than 50 mm above soil level.

(g) Pruning:

Pruning and removal of branches shall be carried out using sharp, clean implements. Pruning shall be carried out with the cut just above and sloping away from an outward facing healthy bud. Removal of branches shall be carried out by cutting outside of a line drawn between the branch bark ridge and the branch collar in such a way that no part of the stem is damaged or torn, and leaving no snags or stumps.

(h) Grass cutting:

(i) Grassed areas shall be cut by manual or mechanical methods reviewed

without objection by the Project Manager and in such a manner that does not cause pulling of roots or damage to planting in or near the grassed area. All cuttings shall be raked off and disposed of within 24 hours after cutting.

(ii) Category 1 grass shall be as stated in the Contract and shall be

reduced by cutting to a height of 50 mm when it reaches 100 mm high.


(iii) Category 2 grass shall be as stated in the Contract and shall be reduced by cutting to a height of 100 mm when it reaches 300 mm high.

(iv) Category 3 grass cutting shall be cutting of areas of hydroseeding which

are stated in the Contract to be subsequently maintained as mown grass.

(i) Litter collection:

All litter exposed by grass cutting shall be gathered up and disposed of within 24 hours.

(j) Post-planting fertilizer:

Post-planting fertilizer shall be applied not less than 100 days, and not more than 300 days, after grassing or planting. The fertilizer shall be applied at a rate of :

(i) 100 g/m² for amenity grass and shrub planting;

(ii) 100 g for each light standard, standard and heavy standard tree;

(iii) 50 g for each seedling and whip tree; and

(iv) 40 g/m² for grass on slopes and grass grown by hydroseeding.

(k) Control of pests and disease:

Pesticide or fungicide shall be applied in accordance with the manufacturer's recommendations to control pests and disease.

(l) Forking over:

Surfaces of bare ground which are subject to surface panning or compaction of the soil shall be forked over in such a manner that roots are not disturbed and plants are not loosened; plants which are disturbed or loosened shall be firmed up and well watered immediately.

(m) Mulching:

All mulch which is disturbed by replacement planting, weeding or watering shall be made good. The Contractor shall also provide additional mulching over areas of forking-over and over areas disturbed by others.

(n) Completion of work:

Immediately before the end of the period for establishment works :

(i) all tree and shrub planting shall be free from weeds;

(ii) all planted and grassed areas shall be free from litter;

(iii) all replacement planting and patching up of grass shall be completed;


(iv) all stakes and ties shall be secure; and

(v) all grassed areas shall be cut and the edges trimmed. 4.7. INSPECTION, TESTING AND COMMISSIONING 4.7.1 Testing : Grass Cover

(a) Tests shall be carried out to determine the grass cover. The tests shall be carried out 100 days after grassing and at the end of the period for establishment works. The grass shall be cut to a height of 300 mm if necessary over the parts of the area to be tested.

(b) The method and number of tests shall be reviewed without objection by the

Project Manager.

(c) Testing to determine the grass cover will be carried out by the Contractor in the presence of the Project Manager.

(d) Tests shall be carried out at locations which are representative of the grassed

area as a whole. At each test location an approximately square area of 10 m² shall be marked.

(e) The percentage of bare ground other than rock and other hard material in

each 10 m² test area shall be measured. (f) At least 90% of each test area shall be covered with grass. (g) If the result of any test for grass cover of landscape softworks and

establishment works does not comply with the specified requirements for gross cover the area shall be rehydroseeded or reseeded in accordance with Clause 4.6.4(f)(i) or (ii) determined by the Project Manager, depending upon the size of the defective area.

4.7.2 Inspection of Establishment Works

An inspection of landscape softworks and establishment works shall be carried out jointly by the Contractor and the Project Manager at monthly intervals to determine the establishment works which are required. The Project Manager shall instruct the Contractor to carry out establishment works which are necessary; the work instructed shall be completed within 14 days after the date of the Project Manager's instruction.


APPENDIX A4.1

BRITISH STANDARDS PUBLICATIONS

B.S. 1992 : Part 4 : 1984

Recommendation for landscape drawings

B.S. 3882 : 1965 (1978)

Recommendation and classification for top soil

B.S. 3936 :

Specification for nursery stock : Part 1 : 1980 Specification for trees and shrubs : Part 4 : 1980 Specification for forest trees : Part 9 : 1968 Bulbs, corms and tubers : Part 10 : 1981 Specification for ground cover plants

B.S. 3969 : 1968 (1975)

Recommendations for turf for general landscape purposes

B.S. 3975 :

Glossary for landscape work : Part 4 : 1966 Plant description : Part 5 : 1969 Horticultural, arboricultural and forestry practice

B.S. 3998 : 1989 Recommendations for tree work

B.S. 4043 : 1989 Recommendations for transplanting root-balled trees

B.S. 4156 : 1967 (1979) Peat

B.S. 4428 : 1989 Recommendations for general landscape operations (excluding hard surfaces)

B.S. 5236 : 1975 Recommendations for the cultivation and planting of trees in the advanced nursery stock category

B.S. 5551 : Fertilizers

B.S. 5837 : 1980

Code of practice for trees in relation to construction (under review)

HONG KONG GOVERNMENT PUBLICATIONS

SIL Technical Guide to Tree Planting and Maintenance

General Materials & Workmanship Specification 1/7 January 2011 Issue No. 5, Volume 1 – Civil & Structural Works Section 5 - Fencing

SECTION 5 FENCING 5.1 GENERAL

The Permanent Works and materials specified below shall comply with the Sections stated, unless otherwise stated in this Section:

(a) handrailing shall comply with Section 35; (b) earthworks shall comply with Section 7; (c) pedestrian guardrailing shall comply with Section 11; (d) formwork and finishes to concrete shall comply with Section 18; (e) reinforcement shall comply with Section 19; (f) concrete shall comply with Section 20; (g) steelwork shall comply with Section 22; and (h) vehicular parapets shall comply with Section 23.

5.2 DESIGN AND PERFORMANCE CRITERIA 5.2.1 Acrylic Sheet Sound Barriers

(a) The design working load for acrylic sheets shall be 6.9 kPa. Each panel shall be assumed to be simply supported unless the Contractor can demonstrate the amount of fixity that the support can offer either by test on Site which is acceptable to the Project Manager or by producing satisfactory test results performed under similar conditions.

(b) Movement joints shall be designed to allow for thermal movement of the

sheeting due to a temperature variation of ±50º and the movement of the structure without affecting their performance in any respect. Sealing compounds, taps and gaskets should be sufficiently flexible to permit movement of the sheeting.

5.3 MATERIALS 5.3.1 Wire

(a) Wire for fencing, including plastic coated wire, shall be galvanised mild steel complying with BS 4102.

(b) Barbed wire shall consist of two line wires and point wire formed in

accordance with BS 4102, Clause 4.1. (c) Galvanised coatings to steel wire shall comply with BS 443. (d) Plastic coatings to steel wire shall comply with BS 4102, Section 6.


5.3.2 Chain Link Fence

Chain link fence shall comply with BS 1722 Part 1. 5.3.3 Plywood

Plywood for hoardings shall comply with BS 6566 and shall have a grade 2 veneer. The bonding adhesive between veneer layers shall be phenol formaldehyde resin adhesive, classified as weather-proof and boil-proof in accordance with BS 1203.

5.3.4 Timber

(a) Timber for fencing shall be of mature growth and shall be seasoned and free from large, loose or dead knots, wood wasp holes, infestation, splits and other defects that will reduce the strength or produce blemishes. The moisture content in timber at the time of fabrication shall not exceed 20%.

(b) Hardwood shall be ‘San Cheung’ (Kapore) and shall have a minimum density

of 720 kg/m3 at 15% moisture content. (c) Softwood shall be cedar, spruce or China fir. (d) Timber that is not to be painted shall be preserved with coal tar creosote. The

creosote shall comply and be applied by pressure impregnation in accordance with BS 144.

5.3.5 Steel

(a) Steel for fencing shall comply with the following: (i) Hot rolled Sections BS 4 Part 1;

(ii) Hot rolled structural Sections:

- Equal and unequal angles BS 4848 : Part 4;

- Hollow Sections BS 4848 : Part 2; and

(iii) Metal washers for general engineering purposes

BS 4360.

5.3.6 Bolts, Nuts, Washers and Fittings

(a) Bolts, nuts and washers for fences shall comply with the following:

(i) ISO metric black hexagon bolts, screws and nuts BS 4190;

(ii) ISO metric black cup and countersunk head bolts and screws with hexagon nuts

BS 4933; and

(iii) Metal washers for general engineering purposes BS 4320.

(b) The length of bolts shall be such that the threaded portion of each bolt projects through the nut by at least one and not more than four, threads.

(c) Fittings, including eye bolt strainers, cleats, winding brackets, stretcher bars,

extension arms, hook bolts and base plates, shall be galvanised mild steel.


(d) Bolts, nuts, washers and fittings for fixing to concrete and timber shall be galvanised. Bolts, nuts, washers and fittings for fixing to steel shall have the same protective treatment as the steel.

(e) Staples shall be “D” Section galvanised wire.

5.3.7 Acrylic Sheet Sound Barriers

(a) Acrylic sheets for sound barriers shall be manufactured from polymethylmethacrylate resin and shall be supplied and erected by a proprietary manufacturer acceptable to the Project Manager.

(b) The light transmission measured in accordance with DIN 5036 shall not be

less than 90% for a 4 mm thick sample. (c) Acrylic sheets shall comply with BS 6262, and in no case be less than 15 mm

thick. The tolerance in thickness shall not exceed ±5%. (d) Acrylic sheets shall carry the manufacturer's guarantee under outdoor

conditions in Hong Kong on the following properties:

(i) Light transmittance; over a period of 10 years the light transmittance shall not decrease by more than 5% from the original value.

(ii) Modulus of elasticity; after 10 years the elastic modulus shall not be less

than 2800 MPa (iii) Tensile strength; after 10 years the tensile yield stress shall not be less

than 60 MPa.

(e) Acrylic sheets shall have impact strength in compliance with Class A materials according to BS 6206.

(f) All exposed edges of acrylic sheets shall be polished. (g) All steel fixings and accessories shall have corrosion protection treatment not

inferior to the structural steel frame shown on the Employer’s Drawings and they shall be painted to the same colour as the structural steel frame.

(h) All acrylic sheets shall be covered with a protective sheeting to the

manufacturer's recommendation during transport, storage on Site, and construction until the application for the Completion Certificate

(i) Fixing details, which require drilling holes in the acrylic sheets are not

acceptable.

5.3.8 Fabrication of Steelwork

Steelwork shall be fabricated in accordance with BS5950: Part 2.


5.3.9 Galvanising to Steel

(a) Steel to be galvanised shall be hot-dipped galvanised in accordance with BS 729 with a minimum coating thickness of 500 g/m2.

(b) Galvanising to steel shall be applied, as far as possible, after welding, drilling

and/or cutting are complete. 5.3.10 Welding Steel

(a) Welds to steel for fencing shall be in accordance with Clause 22.5.2. Weld surfaces shall be clean and flush before application of the protective coating.

(b) Steel shall not be welded after galvanising except with the express permission

of the Project Manager. If permitted, the welded areas shall be free from scale and slag and shall be treated after welding, with an alternative galvanising or zinc coating system, reviewed without objection by the Project Manager.

5.3.11 Concrete Posts

(a) Concrete posts and struts for fencing shall be precast units using Grade 30/10 concrete. The finish to formed surfaces shall be Class F4 and the finish to unformed surfaces shall be Class U5. The tops of posts and all arises shall be rounded or chamfered.

(b) Reinforcement for concrete posts and struts shall be Grade 250 plain round

steel bars. (c) No concrete posts shall be removed from the mould for a period of at least 24

hours and shall not be shifted or transported until at least seven days have elapsed since casting.

5.3.12 Gates

(a) Steel gates shall be of welded construction. The frame shall be square with the corners mitred or saddled.

(b) Chain link infilling in gates shall be of the same type and size as in the

adjoining fence and shall be attached to the framework by stretcher bars. 5.3.13 Storage of Fencing

(a) Plywood and timber posts, rails and struts for fencing shall be stored on level supports in a dry, weatherproof store.

(b) Gates, concrete and steel posts and struts for fencing shall be stored off the

ground on level supports. (c) Damaged fencing materials shall not be used in the Works.


5.4 SUBMISSIONS 5.4.1 Particulars of Fencing

The following particulars of the proposed fencing shall be submitted to the Project Manager for review:

(a) Contractor’s Drawings showing the fabrication details of fences and gates; (b) details of the source, type and properties of all fencing materials; and (c) Contractor’s Drawings showing details, fixings and movement joints (including

calculations) for all acrylic sheet sound barriers. 5.4.2 Samples

The following samples of the proposed materials shall be submitted to the Project Manager together with the particulars referred to Clause 5.4.1 above:

(a) each type of wire and fitting; (b) chain link; (c) acrylic sound barriers; (d) plywood; and (e) precast concrete, steel and timber posts.

5.5 WORKMANSHIP 5.5.1 Tolerances

Fencing shall comply with the following requirements:

(a) the position of posts shall be within 75 mm of the specified position; (b) the level of the top of posts shall be within 25 mm of the specified level; and (c) posts shall be vertical to within 5 mm over the height of the post.

5.5.2 Alignment of Fencing

Fencing shall be erected to a smooth alignment with no abrupt irregularities. The ground shall be trimmed or filled in such a manner that the bottom of the fence will approximately follow the level of the ground. The distance between the bottom of either chain link mesh or hoardings, and the ground, shall not exceed 100 mm.


5.5.3 Posts for Fencing

(a) Straining posts for fencing shall be provided at all ends and corners, at changes in direction, at abrupt changes in level, at gate posts and at intervals not exceeding 30 m along straight lengths of fencing. Struts shall be fitted to straining posts in the direction of each wire secured to the post.

(b) Intermediate posts shall be provided at intervals not exceeding 3.5 m.

5.5.4 Erecting Posts for Fencing

(a) Posts and struts for fencing shall be set in excavations for foundations and the excavations shall be filled with Grade 30/20 concrete up to 50 mm below ground level.

(b) Struts shall be fitted into slots in timber and concrete posts and bolted to steel

posts. (c) The ground surface around posts shall be made good with the same material

as in the adjoining area. 5.5.5 Fixing Wire for Fencing

(a) Line wire, chain link mesh and barbed wire for fencing shall be strained tightly between straining posts. Winding brackets shall be used for straining between steel posts. Winding brackets or eye bolt strainers shall be used for straining between concrete and timber posts. The tension in the wire on each side of straining posts shall be equal. Wire shall not be strained until at least 14 days after concrete has been placed in the foundation.

(b) Chain link mesh shall be secured at each straining post by a stretcher bar and

shall be tied to the line wire by tying wire at 150 mm intervals.

(c) Each line wire and each line of barbed wire shall be secured to each intermediate post by one of the following methods as stated in Table 5.1:

(i) a hairpin staple shall be passed through a hole in the post and secured

to the wire by three complete turns on each side of the post;

(ii) a stirrup shall be passed through a hole in the post and the ends bent over twice;

(iii) the wire shall be threaded through a hole in the post;

(iv) the wire shall be stapled to the post; or

(v) a hook bolt shall be passed through a hole in the post and secured with

a nut and washer.


Table 5.1: Method of Securing Wire to Intermediate Posts

Type of Fence

Type of Wire Type of Post Method of Securing Wire

Strained Wire Line wire Concrete (i), (ii) or (iii) Steel (i), (ii) or (iii) Timber (i), (ii) or (iv)

Barbed wire Concrete (i) or (ii) Steel (i) Timber (i) or (iv)

Chain link Line wire, mesh wire Concrete (i), (ii) or (v) Steel (i) or (iii) Timber (iv)

Barbed wire Concrete (i), (ii) or (v) Steel (i) Timber (iv)

5.5.6 Fixing Gates

Gates shall be hung plumb and shall not be installed until the wire has been strained.

5.5.7 Fixing Timber for Fencing

The ends of timber rails for fencing shall be closely butted together and the rails shall be securely nailed to each post. The ends of plywood sheets in hoardings shall be closely butted together and the sheets shall be securely nailed to each post and to the horizontal rails.

General Materials & Workmanship Specification 1/51 January 2011 Issue No. 5, Volume 1 - Civil & Structural Works Section 6 – Drainage Works

SECTION 6 DRAINAGE WORKS

6.1 GENERAL The Permanent Works and materials specified below shall comply with the Sections stated, unless otherwise stated in this Section. (a) Metalwork for handrailing, ladders, stairs, metal flooring, toe plates and safety

chains shall comply with Section 35 and Section 22.

(b) Earthworks shall comply with Section 7.

(c) Formwork and finishes to concrete shall comply with Section 18.

(d) Steel reinforcement shall comply with Section 19.

(e) Concrete shall comply with Section 20.

(f) Materials for grout shall comply with Section 20.

(g) Water supply pipeworks shall comply with Section 14.

(h) Cable duct systems for electrical and mechanical installations shall comply with Section 13.

6.2 GLOSSARY OF TERMS

6.2.1 Pipes Pipes for drainage works are pipes for conveying sewage, greywater and surface water.

6.3 MATERIALS

6.3.1 Precast Concrete Pipes and Fittings (a) Precast concrete pipes and fittings shall comply with BS 5911:Part 100.

(b) Precast concrete pipes and fittings shall have flexible spigot and socket joints.

6.3.2 Vitrified Clay Pipes and Fittings (a) Vitrified clay pipes and fittings shall comply with BS 65; the pipes and fittings

shall be glazed and shall be the chemical resistant type.

(b) Vitrified clay pipes and fittings shall have flexible mechanical joints.


6.3.3 DI Pipes and Fittings (a) DI pipes and fittings shall comply with BS 4772. Pipes and fittings shall be

lined internally with cement mortar in accordance with BS 4772, Appendix C. Pipes and fitting shall be coated externally with bituminous coating in accordance with BS 4772 Section 16.3.

(b) Flexible joints in DI pipes and fittings shall be the push-in type and shall be capable of withstanding a minimum angular deflection of 4°. Flexible joints shall also be capable of withstanding axial movements and shall allow a minimum withdrawal of 38 mm when there is no deflection of the joint.

(c) Flanged joints in DI pipes and fittings shall be PN 16 rating complying with BS

4504: Section 3.1.

(d) Pipes to be built in to structures shall have puddle flanges welded on.

6.3.4 Grey Iron Pipes and Fittings Grey iron pipes and fittings shall comply with BS 4622.

6.3.5 UPVC Pipes and Fittings (a) Unplasticised (UPVC) pipes and fittings shall comply with the relevant British

Standard stated in Table 6.1.

(b) UPVC pipes and fittings above ground shall have solvent welded spigot and socket joints. UPVC pipes and fittings below ground shall have either solvent welded spigot and socket joints or flexible spigot and socket joints with elastomeric joint rings as stated in the Contract.

(c) Joints and fittings for UPVC pressure pipes complying with BS 3506 shall

comply with the following:

(i) injection moulded UPVC fittings for solvent welding for use with pressure pipes, including water supply : BS 4346: Part 1;

and (ii) mechanical joints and fittings principally of UPVC : BS 4346: Part 2.

(d) Solvent cement for UPVC pressure pipes shall comply with BS 4346: Part 3. (e) The class of UPVC pressure pipes complying with BS 3506 shall depend on

the pressure rating.


6.3.6 GI Pipes and Fittings (a) GI pipes and fittings shall comply with the following:

(i) steel tubes and tubulars suitable for screwing to BS 21 pipe threads : BS 1387, medium grade; (ii) pipe threads for tubes and fittings where pressure-tight joints are made on the threads : BS 21; and (iii) wrought steel pipe fittings (screwed

BSP thread) : BS 1740: Part 1. (b) GI pipes and fittings shall be medium class thickness and shall be galvanized

in accordance with BS 729. Table 6.1: UPVC Pipes and Fittings Use Nominal diameter (mm) British Standard Gravity sewage pipes and fittings above ground

32 - 50 BS 5255 82 - 160 BS 4514

Gravity surface water pipes and fittings above ground

63 - 75 BS 4576: Part1 82 - 160 BS 4514

Gravity sewage and storm water pipes and fittings below ground

110 - 160 BS 4660 200 - 630 BS 5481

Pressure pipes and fittings above and below ground

10 - 600 BS 3506

6.3.7 Polyethylene Pipes and Fittings

(a) Polyethylene pipes and fittings shall comply with the requirements set out in the Appendix A6.6.

(b) Size of polyethylene pipes and fittings shall be designated by the nominal size

in millimeters. Nominal Size shall mean the minimum outside diameter of a pipe, or in the case of a fitting, the minimum outside diameter of the pipe with which the fitting is intended to use. For the purpose of connecting to pipes of other materials or connecting to other non-polyethylene standard fittings which are of the same nominal internal bore, the foIlowing equivalent sizes in DN shall be used:

Polyethylene nominal size Equivalent DN

400 355 450 399 500 443 560 497 630 559 710 630 800 709


6.3.8 Bolts, Nuts and Washers (a) Bolts, nuts and washers for flanged joints, detachable couplings and flange

adapters shall comply with the following:

(i) ISO metric black hexagon bolts, screws and nuts : BS 4190; (ii) metal washers for general engineering purposes : BS 4320; and (iii) the bolts, nuts and washers shall be hot-dip galvanised in accordance

with BS 729. (b) Stainless steel bolts and nuts shall comply with BS 6105, steel Grade A4 and

property Class 80. Washers shall be Grade 316 S 31 in the softened condition complying with BS 1449: Part 2.

(c) Spheroidal graphite iron bolts shall be Grade 500/7 metal complying with BS

2789. (d) Bolts, nuts and washers shall be insulated from electrochemically dissimilar

metal by non-metallic washers and sleeves. (e) Bolts and nuts shall be compatible with the type of joint and shall be obtained

from the same manufacturer as the joint. (f) The length of bolts shall be such that the threaded portion of each bolt

projects through the nut by at least one thread and by not more than four threads.

6.3.9 Elastomeric Joint Rings

(a) Elastomeric joint rings shall comply with BS 2494, Type D. The rings shall be

compatible with the type of joint and shall be obtained from the same manufacturer as the joint.

(b) Elastomeric joint rings for flanged pipes shall be the inside diameter bolt circle

type. The rings shall be natural rubber with a thickness of 3.2 mm and with other dimensions complying with BS 4865: Part 1.

6.3.10 Detachable Couplings and Flange Adapters

(a) Detachable couplings and flange adapters shall be a proprietary type

reviewed without objection by the Project Manager. (b) Detachable couplings and flange adapters shall accommodate the angular

deflection and straight draw stated in Table 6.2 for the different nominal diameters of pipes connected.


Table 6.2: Angular Deflection and Straight Draw Nominal diameter

Detachable coupling Flange adapter Angular

deflection Straight

draw Angular

deflection Straight

draw not exceeding 450 mm ± 6° ± 10mm ± 3° ± 5mm exceeding 450 mm and not exceeding 600 mm

± 5° ± 2.5°

exceeding 600 mm and not exceeding 750 mm

± 4° ± 2°


± 3° ± 1.5°


± 2° ± 1°

exceeding 1800 mm ± 1° ± 0.5°

6.3.11 Anticorrosion Tape (a) Anticorrosion tape shall be a proprietary type reviewed without objection by

the Project Manager. The tape shall be a rubber/bitumen compound with fabric reinforcement and shall be backed with PVC film. The tape shall have a high resistance to cathodic disbonding, acids and alkalis and shall have the minimum properties stated in Table 6.3.

(b) Anticorrosion tape shall be applied to valves, flanged joints, slip-on couplings

and flange adapters. Type 1 shall be used for pipes smaller than 700 mm diameter and Type 2 shall be used for pipes 700 mm diameter and above.

(c) Primer and mastic filler for use with anticorrosion tape shall be compatible

with the tape and shall be a type recommended by the manufacturer of the tape and reviewed without objection by the Project Manager.

Table 6.3: Properties of Anticorrosion Tape (except where stated the values shown are minimum values)

Property Value

Type 1 Type 2 Thickness of PVC backing (μm) 85 500 Tensile strength (N/mm) 8 10 Elongation (%) ≤ 26 ≤ 26 Tear strength (N) 20 36 Adhesion strength (N/mm) 2 2 Holiday test voltage (kV) - single layer - double layer

10 15

10 15

Impact strength (J) 3.5 8 Temperature range (°C) 5 - 60 8 - 60 Total thickness (mm) 1.6 2.0 Mass (kg/m2) 1.8 2.4


6.3.12 Bituminous Coatings (a) Bituminous coatings shall comply with the following:

(i) bitumen based hot applied coating material for protecting iron and steel including suitable primers where required : BS 4147, Type I, Grade C (ii) black bitumen coating solutions for cold application : BS 3416, Type II.

(b) Bituminous coatings used for repairing joints and coatings shall be compatible with the adjacent coating.

6.3.13 Aggregates for Granular Bed and Granular Fill

(a) Granular bed shall be Type A material and granular fill shall be Type B

material.

(b) Type A or Type B material shall consist of hard, clean, crushed slag, gravel, crushed rock, crushed concrete or crushed inert demolition material having a grading within the limits of Table 6.4. The ten percent fines values shall be at least 50kN. The material passing the 425μm BS test sieve shall be non-plastic when tested in accordance with BS1377.

(c) Type A and Type B material shall be obtained from a source reviewed without objection by the Project Manager.

(d) Aggregates for granular bed shall have the compacting fraction values stated in Clause 6.6.3(d).

Table 6.4: Type of Aggregates for Granular Bed BS test sieve Percentage by mass passing Metric Type A Type B 63 mm 37.5 mm 20 mm 10 mm 3.35 mm 600 mm 75 mm

- 100 - 45 – 100 25 – 80 8 – 45 0 – 10

100 85 – 100 0 – 20 0 – 5 - - -

6.3.14 Joint Filler and Compressible Padding

(a) Joint filler for joints in concrete bed, haunch and surround shall be a

proprietary type reviewed without objection by the Project Manager and shall be a firm, compressible, single thickness, non-rotting filler. The thickness of the filler shall be as stated in Table 6.5.


(b) Compressible padding between pipes and supports shall be bitumen damp-proof sheeting complying with BS 743.

Table 6.5: Joint Filler for Concrete Bed, Haunch and Surround Nominal diameter of pipe Thickness of joint filler (mm) less than 450 mm 18 450 mm - 1200 mm 36 exceeding 1200 mm 54

6.3.15 Polyethylene Sheeting

Polyethylene sheeting shall be impermeable and shall have a nominal thickness of 0.125 mm.

6.3.16 Precast Concrete Manholes Precast concrete manhole units shall comply with BS 5911: Part 200. Cover slabs and reducing slabs shall be reinforced as required to comply with the load test requirements stated in BS 5911: Part 200. The type of cement for the manufacture of precast concrete manhole units, cover slabs, and reducing slabs shall be as stated in BS 5911: Part 200, or combination of PFA and OPC complying with BS 12, or PPFAC. The PFA content shall not exceed 40% by mass of the cementitious content.

6.3.17 Chambers and Gullies (a) Precast concrete chambers and gullies shall comply with BS 5911: Part 2.

Cover slabs shall be reinforced as required to comply with the load test requirements stated in BS 5911: Part 2. The types of cement for the manufacture of precast concrete chambers and gullies, and cover slabs shall be as stated in BS 5911: Part 2, or a combination of PFA and OPC complying with BS 12, or PPFAC. The PFA content shall not exceed 40% by mass of the cementitious content.

(b) Vitrified clay gullies shall comply with BS 65.

6.3.18 Step Irons Step irons shall comply with BS 1247. Step irons shall be malleable cast iron complying with BS 6681 and shall be hot-dip galvanised in accordance with BS 729.

6.3.19 Manhole Covers, Gully Gratings and Kerb Overflow Weirs (a) Manhole covers, gully gratings and kerb overflow weirs shall be Grade 50 cast

iron complying with BS 1452; bolts and nuts shall comply with BS 4190.

(b) Covers, gratings and weirs shall be cleanly cast, free from air holes, sand holes, cold shuts and chill and shall be neatly dressed and fettled. Castings shall be free from voids whether due to shrinkage, gas inclusions or other causes. Bolts and nuts shall not be over tightened.


(c) The dimensions of the different types of covers, gratings and weirs shall be as stated in the Contract; the test loads which the covers and gratings are required to withstand, and the minimum masses of covers gratings and weirs, shall be as stated in Tables 6.6, 6.7 and 6.8.

(d) Covers, gratings and weirs shall have the manufacturer's name cast integrally

with the unit in a raised form and shall be protected with bituminous coating. Covers shall have a raised design on the top surface as stated in the Contract.

(e) The Contractor shall provide the Project Manager two keys for each pattern of

cover used. Table: 6.6: Details of Manhole Covers and Frames

Type of manhole cover and frame

Minimum mass (kg)

Grade

Test requirements

Diameter of block (mm)

Test load (t)

Double triangular manhole cover and frame

180 Medium duty 100 5

Double triangular manhole cover for sewers

130 Heavy duty 300 30

Frame 105 Heavy duty 300 30 Double triangular desilting manhole cover for sewers Frame

290

165

Heavy duty

Heavy duty

300

300

30

30 Double seal terminal manhole cover for sewers - Type MA2-29/29A & B - Type MA2-45/45A & B - Type MC2-29/29A & B - Type MC2-45/45A & B

- - - -

Heavy duty Heavy duty

Medium duty Medium duty

300 300 100 100

20 20 5 5


Table 6.7: Details of Gully Gratings and Frames

Type of gully grating and frame

Minimum mass (kg)

Grade

Test requirements Diameter of

block (mm)

Test load (t)

Grating for hinged gully grating Type GA2-325 Frame

28.0

24.5

Heavy duty

Heavy duty

300

300

20

20 Grating for double triangular gully grating Type GA1-450 Shallow frame - adjacent to kerb - away from kerb Deep frame - adjacent to kerb - away from kerb

57.5

33.5 36.5

40.5 44.0

Heavy duty



300

300 300

300 300

20

20 20

20 20

Grating for hinged gully grating Type GA2-450 Frame

61.5

37.0

Heavy duty

Heavy duty

300

300

20

20 Table 6.8: Details of Kerb Overflow Weirs Type of kerb overflow weir Minimum mass (kg) Type 1-325 39.5 Type 3-325 31.5 Type 1-450 44.0 Type 3-450 36.5 Type 4-450 33.0

6.3.20 Penstocks

(a) Penstocks shall comply with the following requirements:

(i) frames and gates shall be cast iron complying with BS 1452, Grade 220;

(ii) stems shall be stainless steel complying with BS 970: Part 1, Grade 316

S 31; (iii) operating nuts shall be gunmetal complying with BS 1400, Grade LG2; (iv) sealing faces shall be phosphor bronze complying with BS 2874, Grade

PB 102; (v) sealing strips at inverts of flush invert penstocks shall be elastomer

complying with ASTM D 2000; (vi) assembly and fixing nuts and bolts shall be stainless steel complying

with Clause 6.3.7(b); and (vii) adjustable wedges shall be phosphor bronze complying with BS 2874,

Grade PB 102 or stainless steel complying with BS 970: Part 1, Grade 316 S 31.


(b) Penstocks shall be designed for on-seating pressure or off-seating pressure or both on-seating and off-seating pressures as stated in the Contract.

(c) Sealing faces shall be of rectangular sections and shall be fixed to the frames

and gates using taperhead screws of the same material as the sealing faces. (d) Adjustable wedges shall have sufficient contact areas with the gates to

minimise wear. (e) Frames shall include guide rails or guide faces for gates. Clearance within

guides shall be as small as practicable such that the gates will not vibrate under flow conditions.

(f) Penstocks shall have rising stems unless otherwise stated in the Contract.

Rising stems shall have perspex protection tubes with open/close indicators.

6.3.21 Gate Valves (a) Gate valves shall comply with BS 5150 and with the following requirements:

(i) bodies and wedges shall be cast iron complying with BS 1452, Grade 220 and shall have renewable gunmetal seat rings;

(ii) gunmetal for renewable seat rings shall be Grade LG2 complying with

BS 1400; (iii) stem nuts shall be gunmetal complying with BS 1400, Grade LG2; (iv) stems shall be aluminium bronze complying with BS 2874, Grade CA

104; and (v) assembly and fixing nuts and bolts shall be stainless steel complying

with Clause 6.3.7(b). (b) Gate valves shall be double flange-ended solid wedge type with nominal

pressure designation PN 16. Flanges shall be PN 16 complying with BS 4504: Part 1.

(c) Gate valves shall have outside screw rising stems unless otherwise stated in

the Contract. Rising stems shall have perspex protection tubes with open/close indicators.

(d) Gate valves shall be fitted with a plate showing the operating position of the

valve in the closed, quarter closed, half closed, three-quarters closed and open positions.

(e) Chains for chain operated gate valves shall be mild steel complying with BS

970:Part 1 and hot-dip galvanized in accordance with BS 729. The chains shall be continuous.

(f) Gear boxes shall have enclosures effectively sealed against the intrusion of

foreign bodies and moisture to the degree IP68 (i.e. dust-tight and protection against complete and continuous submersion in water from 15m or 50ft) as defined in the standard IEC 60529.


6.3.22 Flap Valves (a) Flap valves shall comply with the following requirements:

(i) frames and flaps shall be cast iron complying with BS 1452, Grade 220; and

(ii) sealing faces and hinge pins shall be gunmetal complying with BS 1400,

Grade LG2. (b) The flap shall be hung with double hinges and secured with hinge pins. (c) Flanges for flange mounting types of flap valves shall be PN 16 complying

with BS 4504: Part 1.

6.3.23 Sludge Valves (a) Sludge valves shall comply with the following requirements:

(i) bodies and valve sections shall be cast iron complying with BS 1452, Grade 220;

(ii) sealing faces and stem nuts shall be gunmetal complying with BS 1400,

Grade LG2; and (iii) stems shall be aluminium bronze complying with BS 2874, Grade CA

104. (b) The stems of sludge valves shall operate through non-rising stem nuts

housed in bridges bolted over the body sections. (c) Outlet flanges of sludge valves shall be PN 16 complying with BS 4504:

Section 3.1.

6.3.24 Air Valves (a) Air valves shall be of the elongated body type and shall have a pressure

rating of 3 bars unless otherwise stated in the Contract.

(b) Dual orifice air valves shall have:

(i) a small orifice valve for releasing air at working pressure, and (ii) a large orifice valve for allowing air to pass at atmospheric pressure

during emptying and filling of pipework. (c) The bodies and covers of small and large orifice valves shall be cast iron

complying with BS 1452, Grade 220; the trim and float shall be stainless steel complying with BS 970:Part 1, Grade 316 S 31.

(d) Small orifice valves shall have an adjustable Vitron or equivalent orifice button

to ensure positive sealing. Large orifice valves shall have a Buna-N or equivalent seat.


(e) The valve inlet of small orifice valves shall be 75 mm diameter and the valve outlet shall be 25 mm diameter; the venting orifice shall be 5 mm diameter. The valve inlet and the valve outlet of large orifice valves shall be 75 mm diameter.

(f) Air valves shall be provided with isolating gate valves.

6.3.25 Fittings for Penstocks and Valves (a) Handwheels and tee keys for penstocks and valves shall turn in a clockwise

direction for closing. Handwheels shall have smooth rims and the direction of opening and closing shall be clearly cast on the handwheel. The opening effort required at any point on the handwheel rim shall not exceed 250 N when operated against the full unbalanced pressure.

(b) Extension stems for penstocks and valves shall be stainless steel of the same

grade as the stems. Extension stems shall be connected by muff couplings.

(c) Handwheels, tee keys, headstocks, guide brackets for stems, supporting brackets, surface boxes and other fittings for penstocks and valves shall be cast iron complying with BS 1452.

(d) Bolts and nuts for fixing penstocks and valves to structures shall be stainless

steel complying with Clause 6.3.7(b). Bolts shall be indented foundation bolts. (e) Grout for filling rebates and box-outs shall be a proprietary type reviewed

without objection by the Project Manager and shall contain a non-shrink admixture.

6.3.26 Foam Concrete

Foam concrete for filling abandoned pipes, culverts, manholes and voids shall be composed of OPC (or PPFAC), fine aggregate, water, admixtures for accelerating or retarding the setting time and foam to reduce the density and to produce a flowing self levelling material.

6.4 SUBMISSIONS

6.4.1 Particulars of Pipes, Joints and Fittings (a) The following particulars of the proposed pipes, joints and fittings for drainage

works shall be submitted to the Project Manager for review without objection:

(i) manufacturers' literature, including details of: • manufacturing process; • pressure and temperature ratings; • permissible values of straight draws and angular deflection of

flexible joints; • recommendations for handling, storage, laying, jointing and repair;

and • drilling and tapping equipment for connections to pipes; and


(ii) a certificate for each material showing the manufacturer's name, the date and place of manufacture and showing that the material complies with the requirements stated in the Contract and including results of tests required in accordance with the relevant British Standard.

6.4.2 Particulars of Anticorrosion Tape and Joint Filler

(a) The following particulars of the proposed anti-corrosion tape and joint filler for

drainage works shall be submitted to the Project Manager for review without objection:

(i) manufacturer's literature for the joint filler and anticorrosion tape; and

(ii) certificates for anticorrosion tape and joint filler showing the

manufacturers' name, the date and place of manufacture and showing that the material complies with the requirements stated in the Contract and including results of tests in accordance with the Contract.

6.4.3 Particulars of Aggregates for Granular Bed

A certificate for each type of aggregate showing the source of the aggregate and showing that the aggregate complies with the requirements stated in the Contract, and including the results of tests in accordance with the Contract, shall be submitted to the Project Manager for review without objection for the proposed aggregates for granular bed for drainage works.

6.4.4 Particulars of Manholes, Chambers and Gullies (a) The following particulars of the proposed materials for manholes, chambers

and gullies for drainage works shall be submitted to the Project Manager for review without objection:

(i) a certificate for each type of manhole and chamber unit and for each

type of gully showing the manufacturer's name, the date and place of manufacture and showing that the materials comply with the requirements stated in the Contract and including results of tests required in accordance with the relevant British Standard;

(ii) a certificate for step irons showing the manufacturer's name, the date

and place of manufacture and showing that the step irons comply with the requirements stated in the Contract, and including results of tests required in accordance with the Contract; and

(iii) a certificate for each type of manhole cover, gully grating and kerb

overflow weir showing the manufacturer's name, the date and place of manufacture and showing that the materials comply with the requirements stated in the Contract and including results of loading tests in accordance with the Contract.


6.4.5 Particulars of Penstocks and Valves (a) The following particulars of the proposed penstocks and valves for drainage

works shall be submitted to the Project Manager for review without objection:

(i) manufacturer's literature, including details of: • materials; • pressure ratings; and • recommendations for handling, storage and installation; and

(ii) Contractor’s Drawings showing details of the penstocks and valves, including lengths of stems and details of handwheels, tee keys, extension stems, headstocks, guide brackets for stems, supporting brackets, surface boxes and other fittings, and positions and sizes of rebates and box-outs.

6.4.6 Particulars of Foam Concrete and OPC/PFA Grout

(a) The following particulars of the foam concrete mix (or grout mix) and

procedure for filling abandoned pipes, culverts, manholes and voids shall be submitted to the Project Manager for review without objection:

(i) proportions of each constituent;

(ii) source of supply; (iii) details of mixing; (iv) setting time; (v) strength; (vi) shrinkage expected (for OPC/PFA grout); (vii) details of mixing and grouting equipment; and (viii) method of grouting, including details of trials.

6.4.7 Particulars of Tests

(a) The following particulars of the proposed procedures for tests on pipelines

and penstocks for drainage works shall be submitted to the Project Manager for review without objection:

(i) test equipment and method of setting up the equipment; (ii) calibration certificates for pressure gauges; (iii) procedure for carrying out the test; and (iv) programme for testing.


6.4.8 Particulars of CCTV Inspections (a) The following particulars of the proposed procedure for CCTV inspections

shall be submitted to the Project Manager for review without objection:

(i) names and experience of persons carrying out or supervising the inspections;

(ii) details of equipment; (iii) details of the format of report; and

(iv) examples of video films and photographs obtained from inspections

employing the same equipment.

6.4.9 Particulars of Diversions of Flow Particulars of the proposed procedures for diversions of existing flows shall be submitted to the Project Manager for review without objection.

6.5 WORKMANSHIP

6.5.1 Transport, Handling and Storage of Materials

(a) Transport, handling and storage of pipes, joints and fittings:

(i) Pipes, joints and fittings for drainage works shall be transported, handled and stored in accordance with the manufacturers' recommendations and in a manner which will not result in damage or deformation to the pipes, joints and fittings or in contamination of the pipes, joints and fittings.

(ii) Pipes, joints and fittings shall be protected from damage and damaged

pipes, joints and fittings shall not be used in the Permanent Works. Pipes, joints and fittings shall be securely packed and supported to prevent movement when being transported.

(iii) UPVC pipes, joints and fittings shall be protected from exposure to

conditions which may affect the material.

(iv) Bolts and nuts shall be packed in sealed metal containers.

(v) Elastomeric joint rings shall be packed in bags and lubricant for joints shall be stored in sealed containers marked to identify the contents. The rings and lubricant shall be protected from exposure to conditions which may affect the material.

(b) Handling of pipes and fittings:

(i) Pipes and fittings shall be handled manually or by using lifting appliances or chains, wire ropes or canvas slings of a type recommended by the pipe manufacturer and reviewed without objection by the Project Manager. Hooks shall not be used.


(ii) Slings shall be placed around the pipes and fittings and padding shall be provided at points of contact between pipes and fittings and metal lifting appliances or slings. Pipes and fittings shall not be handled by means of metal slings passed through the pipes.

(iii) Pipes and fittings shall not be subjected to rough handling, shock

loading or dropping. (c) Storage of pipes:

(i) Pipes shall be stored horizontally at least 75 mm above the ground on wedged timber bearers and shall not be strung out along the route of the pipeline. The pipes shall be securely wedged to prevent sideways movement.

(ii) Socket and spigot pipes shall be stored with the sockets alternating and

in such a manner that loads are not applied to the sockets.

(iii) The height of stacks of pipes shall not exceed the maximum height recommended by the pipe manufacturer.

(d) Storage of anticorrosion tape and joint filler:

Anticorrosion tape and joint filler shall be stored in accordance with the manufacturer's recommendations in a dry, weatherproof store with a raised floor.

(e) Handling and storage of aggregates for granular bed:

Aggregates for granular bed shall not be handled or stored in a manner which will result in mixing of the different types and sizes or in contamination of the aggregates. Different types and sizes of aggregates shall be stored in separate stockpiles.

(f) Handling and storage of units for manholes, chambers and gullies:

(i) Units for manholes, chambers and gullies shall be lifted only at the lifting points recommended by the manufacturer and shall not be subjected to rough handling, shock loading or dropping.

(ii) Units for manholes, chambers and gullies shall be stored off the ground

on level supports and in a manner which will not result in damage or deformation to the units or in contamination of the units. The units shall be protected from damage and damaged or deformed units shall not be used in the Permanent Works.

(g) Storage of covers, gratings, weirs, penstocks and valves:

Manhole covers, gully gratings, kerb overflow weirs, penstocks and valves, including fittings, shall be stored off the ground on level supports and in a manner which will not result in damage to the units or in contamination or deformation of the units. The units shall be protected from damage and damaged or deformed units shall not be used in the Permanent Works.


6.5.2 Excavation (a) Excavation for any section of a trench for drainage works shall not commence

until the nature, location and size of existing utilities which may be affected by the excavation have been ascertained and the setting out details have been reviewed without objection by the Project Manager.

(b) The effective trench width of trenches for drainage works shall not exceed the

relevant effective trench widths stated in Table 6.9 for the different diameters of pipe. Unless otherwise stated in the Contract, effective trench width for different trench profiles shall be measured in accordance with the requirements of the Hong Kong Government Drainage Services Department Standard Drawings.

Table 6.9: Effective Trench Widths

Nominal Diameter of pipe (mm)

Effective trench width (mm)

Nominal diameter of pipe (mm)

Effective trench width (mm)

100 550 1125 2200 150 600 1200 2300 225 700 1350 2450 300 750 1500 2600 375 1050 1650 2800 450 1150 1800 2950 525 1200 1950 3150 600 1350 2100 3350 675 1450 2250 3400 750 1500 2400 3500 825 1600 2550 3650 900 1900 2700 3800 975 2000 2850 3950

1050 2050 3000 4150 (c) The bottom of the excavation shall be formed to the levels and falls as stated

in the Contract and well rammed and consolidated. Any backfill in the areas of overbreak shall be provided by material reviewed without objection by the Project Manager.

(d) The sides of trenches, manholes and other excavations shall be adequately

supported at all times. Where shown on the Employer’s Drawings or directed by the Project Manager the supports shall be left in trenches or pits.

(e) The materials excavated in forming pipe drains shall, if containing materials

as defined in Clause 7.3.1(b), be disposed of off Site and replaced with fill material. Excavated fill material shall be set aside for use as fill.

(f) Surplus material shall be used for fill or disposed of in accordance with Clause

7.5.1 as agreed with, or directed by the Project Manager.


6.5.3 Laying and Bedding Pips (a) Laying pipes

(i) The Contractor shall allow the Project Manager to inspect trenches, bedding, pipes, joints, fittings and valves before pipelaying for drainage works starts. The Contractor shall notify the Project Manager before pipelaying starts in any part of the Permanent Works.

(ii) The Contractor shall inspect pipes, joints, fittings and valves, including

internal and external coatings, immediately before and after pipelaying; valves shall be inspected to ensure that they are in working order and are capable of being fully opened and closed. Deleterious material shall be removed and damage shall be repaired immediately before and after pipelaying.

(iii) The inside of pipelines shall be kept clean and free from water, dirt,

stones, debris and deleterious material. Except when pipes are being jointed, the open ends of pipelines shall be sealed with a wooden plug or stopper.

(iv) Measures shall be taken to prevent flotation of pipes.

(v) Pipelaying, testing and backfilling shall follow as closely as practicable

on excavation of the trench.

(vi) Pipelines shall be laid in an uphill direction with sockets facing uphill.

(vii) Pipes shall be laid in such a manner that water will not pond in locations with zero or shallow gradients and such that the pipes will comply with the specified tolerances.

(b) Bedding pipes

(i) Surfaces on which pipes for drainage works will be laid shall be cleaned and objects which may damage the pipes shall be removed before pipes are laid.

(ii) The bottom of trenches on which pipes will be laid directly shall be

shaped to support the pipes uniformly along the length of the barrel; holes shall be dug to prevent pipes resting on the sockets and to allow the pipes to be jointed.

(c) Laying of Polyethylene Pipe

(i) The laying of poIyethylene pipe shall comply with CP 3 12: Part 3: 1973.

(ii) Storage and jointing of polyethylene pipe and fittings shall be in strict

accordance with the manufacturer's recommendations and to the satisfaction of the Project Manager.

(iii) Hot bending of polyethylene pipe is not permitted.

(iv) Dragging of polyethylene pipe over trench bottom or over the ground is

not permitted.


(v) Polyethylene pipe and fittings to be surrounded by concrete shall be wrapped with three layers of polythene sheeting having a nominal film thickness of 0.1mm.

(vi) Naked flame inside trench shall not be used unless with the permission of the

(vii) Project Manager.

(viii) Before commencing laying of polyethylene pipe into trenches, the

Contractor

(ix) shall request the Project Manager to examine the trench if it is contaminated by strong acid, detergents and hydrocarbons including petrol and solvents. If in the opinion of the Project Managert the area is contaminated by such chemicals, the Contractor shall submit a remedial proposal to the Project Manager for review without objection before proceeding with the work.

6.5.4 Cutting Pipes

(a) Pipes for drainage works shall be cut and the ends shall be prepared in

accordance with the manufacturers' recommendations; purpose-made equipment recommended by the manufacturer and reviewed without objection by the Project Manager shall be used for cutting the pipes.

(b) Cut ends of pipes shall be square or cut to the correct angle and without

damage to the pipe or coating. Cut ends shall be trimmed and chamfered to suit the type of joint and in such a manner that elastomeric joint rings will not be damaged by the cut end.

(c) Pipes requiring to be cut to form closing lengths shall not be cut until adjacent

pipes have been laid and jointed and the length to be cut can be accurately measured.

(d) Reinforcement in precast concrete pipes which are cut shall be cut back flush

with the concrete and protected with epoxy resin.

(e) Pipes which terminate at the inside face of structures shall be cut such that the end of the pipe is flush with the face.

6.5.5 Jointing Pipes

(a) General:

(i) Pipes for drainage works shall be jointed in accordance with the manufacturers' recommendations and using jointing equipment and jointing materials recommended by the manufacturer and reviewed without objection by the Project Manager.

(ii) The Contractor shall inspect pipes, joints, fittings and valves, including

internal and external coatings, immediately before and after jointing. Deleterious material shall be removed and damage shall be repaired immediately before and after jointing. Surfaces which are to be jointed and jointing materials shall be cleaned immediately before jointing. Pipes shall be cleaned out with clean water.


(iii) All joints in pipelines shall be watertight.

(iv) The widths of gaps at joints shall be in accordance with the

manufacturers' recommendations and shall be achieved by marking the outside of the pipe by using metal feelers. The position of elastomeric joint rings shall be checked by using metal feelers after jointing.

(v) Gaps at joints in pipes shall be protected after jointing, by methods

reviewed without objection by the Project Manager, to prevent dirt, stones or other material entering the joint.

(b) Flanged joints:

(i) Flanged joints in pipes for drainage works shall be provided as stated in Clause 6.5.5(b)(ii).

(ii) Bolt holes in flanged joints shall be orientated symmetrically about the

vertical diameter with no bolt holes on the vertical diameter. Elastomeric joint rings shall be the correct size and shall not protrude into the bore of the pipe. The rings may be temporarily fixed to the face of the flange using a minimum amount of adhesive of a type recommended by the manufacturer; jointing compound or paste shall not be used for this purpose.

(c) Flexible collar joints:

(i) Flexible collar joints in pipes for drainage works shall be provided as stated in Clause 6.5.5(c)(ii) to (iv).

(ii) The elastomeric joint rings shall be placed in position inside the grooves

of the sleeve. The ends of the pipes shall be well smeared with lubricant over a distance of at least 100 mm from the end of the pipe.

(iii) The sleeve shall be placed on the end of the laid pipe and pushed home

to the location mark on the pipe. The location mark shall be at a distance of half the length of the sleeve minus 3 mm from the end of the pipe unless otherwise recommended by the manufacturer.

(iv) The pipe which is to be jointed to the laid pipe shall be placed in the

sleeve and pushed home to the location mark on the pipe. (d) Push-in joints:

Push-in joints in pipes for drainage works shall be made by smearing the elastomeric joint ring with lubricant and placing the ring in position on the spigot end of the pipe. The spigot shall be placed in the socket of the laid pipe and pushed home.

(e) Detachable joints:

(i) Detachable joints in pipes for drainage works shall be jointed as stated in Clause 6.5.5(e)(ii) and (iii).


(ii) Both CI flanges, the elastomeric joint rings and the central collar shall be placed over the ends of the pipes before the pipes are placed to the required line and level; a gap of between 5 mm and 6 mm shall be left between the ends of the pipes.

(iii) The flanges, elastomeric joint rings and central collar shall be moved

into position at the ends of the pipes; the central collar shall be positioned centrally over the gap between the ends of the pipe before the bolts are tightened.

(f) Flange adapters:

Joints with flange adapters in pipes for drainage works shall be made by placing the flange adaptor on the plain end before the bolts are tightened.

(g) Solvent welded joints:

Solvent welded joints in pipes for drainage works shall be made by applying solvent cement to the pipes to be jointed and pushing the pipes home. Surplus solvent shall be removed after jointing. Solvent welded pipes jointed outside the trench shall not be placed in the trench until the solvent setting period recommended by the manufacturer has elapsed. In addition, any material or thing contaminated by the solvent shall not be left in the pipe or trench.

(h) Screw joints:

(i) Screw joints in pipes for drainage works shall be made using a threaded coupler. The threaded surfaces of the pipes and coupler shall be cleaned and the threads shall be painted with two coats of bituminous paint. The pipe thread shall be wrapped with three turns of spun yarn and the joint tightened using purpose made tools. Coal tar compounds or white lead paint shall not be used. Locking nuts to branch connections shall be tightened. Branch connections shall not protrude inside the pipe.

(ii) Cast iron pipes shall be laid and bedded one at a time. Each cast iron

pipe should bear evenly on it’s bed. Joint holes shall be cut in the foundation for the purpose of making joints. The spigot of each pipe shall fit easily into the socket of the preceding pipe without any jamming or twisting and shall be pushed well home so that the inverts of the socket and spigot when joined shall be level. Joint gaskets shall be formed with about 2 turns of yarn caulked tightly to the bottom of the socket, a depth of at least 50 mm being left in the socket for lead jointing, which shall be run in molten and caulked into the edge of the socket. Proprietary joints may be proposed for review without objection by the Project Manager.


(i) Jointing Polyethylene Pipes (i) Jointing system permitted for polyethylene pipes are as follows:

• End-load-resistant, mechanical - metal flanged joint and flange adaptor - collar type with a metal body and metal or rubber compression

rings • Heat fusion

- butt fusion (with external debeading) - electro-fusion

• Heat fusion saddle

(ii) Site fusion jointing shall be made in accordance with WIS No. 4-32-08 using automatic equipment with data printout facilities

(iii) A specific joint number shall be assigned to each heat fusion joint and a sketch showing the location of the joint shall be prepared. In case of butt fusion joint, the removed beads shall be properly stored in a transparent plastic bag which shall be marked to indicate the joint number and whether the beads are external or internal beads. External and internal beads for the same joint shall be placed in two different plastic bags. The sketch, data printout, the name of the jointer, and all other information as required by the Project Manager together with beads (if the joint is a butt fusion joint) for each heat fusion joint shall be submitted to the Project Manager for review without objection within three calendar days after completion of the joint.

(iv) For socket fusion, electro-fusion and heat fusion saddle jointings, the

fusion areas of polyethylene pipes shall be cleaned by using isopropanol wipes before and after scrapping. The fusion areas of the fittings shall also be cleaned by using isopropanol wipes before connecting the polyethylene pipes to the fittings.

6.5.6 Protection of Joints

(a) Flanged joints, detachable couplings and flange adapters on buried pipes for

drainage works shall be protected as stated in Clause 6.5.6(b) to (d).

(b) The joint, including bolts and nuts, shall be cleaned to remove all moisture, dust, oil, grease and deleterious material. Bolts and nuts shall be painted with two coats of bituminous paint and the joint shall be coated with primer. Mastic filler shall be applied in such a manner that all depressions, corners and voids between the bolts and nuts are filled and a smooth surface is available on which to apply the anticorrosion tape.

(c) At least two layers anticorrosion tape shall be applied to all parts of the joint

and to the adjacent pipe for at least 200 mm beyond each end of the joint. The tape shall be applied in accordance with the manufacturer's recommendations and shall be wrapped spirally around the joint and pipe with at least 55% overlap per spiral.

(d) The tape shall be moulded manually after application to take up the contours

of the parts being protected.


6.5.7 Repairs to Coatings and Linings Damage to coatings and linings of pipes for drainage works shall not be repaired unless permitted by the Project Manager. If permitted, repairs shall be carried out using materials recommended by the manufacturer and reviewed without objection by the Project Manager.

6.5.8 Thrust and Anchor Blocks (a) Thrust or anchor blocks shall be used to resist forces at bends, branches and

stopends in pressure pipelines for drainage works except where self anchoring joints are used. Concrete for thrust and anchor blocks shall be Grade 20.

(b) The bearing face, and other faces stated in the Contract, of concrete anchor

and thrust blocks shall be cast directly against undisturbed ground; the faces of excavations shall be trimmed to remove loose material before concreting. Excavation required for the block beyond the trench width shall be carried out after the pipe or fitting has been jointed. Excess excavation beyond the face at the block shall be filled with concrete of the same grade as the block.

(c) Internal pressure shall not be applied to the pipeline until thrust and anchor

blocks have developed the specified grade strength.

6.5.9 Bed, Haunch and Surround

(a) Granular bed:

(i) Granular bed to pipelines for drainage works shall be constructed as stated in Clause 6.5.9(a)(ii) to (iv).

(ii) Aggregates for granular bed shall be deposited in the trench in layers

not exceeding 150 mm thick and for the complete width of the trench. Each layer shall be compacted using a plate vibrator or by other methods reviewed without objection by the Project Manager.

(iii) Holes shall be dug in the granular bed to prevent pipes resting on the

sockets and to allow the pipes to be jointed. The pipes shall be laid directly on the granular bed; temporary supports shall not be used.

(iv) After the pipes have been jointed, aggregate shall be deposited in

layers not exceeding 150 mm thick equally on both sides of the pipe to the specified level for the complete width of the trench. Each layer shall be compacted using a plate vibrator.

(b) Concrete bed, haunch and surround:

(i) Concrete bed, haunch and surround to pipelines for drainage works

shall be constructed as stated in Clause 6.5.9(b)(ii) to (vii).

(ii) Concrete for concrete bed, haunch and surround shall be Grade 20.

(iii) Polyethylene sheeting or a blinding layer shall be placed on the trench bottom before concreting.


(iv) Pipes shall be supported at the required level by Grade 20 precast concrete wedges, blocks or cradles. One support shall be placed adjacent to each end of each pipe and the spacing between supports shall not exceed 3 m. Compressible sheeting shall be placed between the pipes and supports.

(v) Flexible joints shall be formed in concrete bed, haunch and surround at

flexible joints in pipelines. Joint filler shall be placed next to the flexible joint in the pipeline and shall extend for the complete thickness of the bed, haunch and surround.

(vi) Concrete shall be placed evenly over the complete width of the bed and

over the complete length of the pipe being concreted up to a level of 25 mm below the underside of the pipe. Concrete shall then be placed on one side of the pipe only and worked under the pipe until the concrete spreads under the pipe. Concrete shall then be placed equally on both sides of the pipe to the specified level.

(vii) Pipes for drainage works which are 1 m or less below the surface of a

carriageway shall be protected with Grade 20 concrete surround.

(viii) The aggregate for Grade 20 concrete stated in Clause 6.5.9(b)(i) to (vii) shall be natural stone, crushed rock or crushed concrete. Such Grade 20 concrete shall have the following minimum cementitous content:

Exposure condition Minimum cememtitous content (kg/m3) Moderate 280 Severe 330

(c) Fill material surround:

(i) Fill material surround to pipelines for drainage works shall be deposited and compacted as stated in Clauses 7.4.34 and 7.4.35.

(ii) Fill material surround to underfloor drainage pipes and perforated

perimeter drain pipes shall be uniform, clean and free draining granular material with less than 5% passing 63 μm.

(d) Installation of drainage pipe support in structures:

(i) The locations of the brackets shall be determined by the Contractor and arranged to satisfy the following requirements:

- the maximum permitted spacing between brackets for pipe support

indicated on the Employer’s Drawings shall not exceeded; - minor reductions in the maximum permitted spacing may be made to

avoid clamps coinciding with pipe joints; and - a clear distance of at least 50 mm shall be maintained between

socket fixings and adjacent reinforcing bars or tendons.

(ii) The interface between the brackets and the concrete shall be protected by an inert layer of corrosion resisting tape reviewed without objection by the Project Manager.


6.5.10 Tolerances (a) Tolerances: pipelines drainage works:

(i) Except as stated in Clause 6.5.10(a)(ii), pipelines for drainage works shall comply with the following requirements: • the line of gravity pipelines shall be within 20 mm of the specified

line; • the invert level of gravity pipelines shall be within 6 mm of the

specified invert level and there shall be no backfall at any point; • the line of pressure pipelines shall be within 50 mm of the specified

line; and • the invert level of pressure pipelines shall be within 20 mm of the

specified invert level.

(ii) Termination pipes in pipelines for drainage works which are designed to connect to pipes or fittings laid by others shall comply with the following requirements: • the position of the centre of the termination face of the pipe in the

longitudinal direction shall be within 10 mm of the specified position;

• the position of the centre of the termination face of the pipe in the lateral direction shall be within 3 mm of the specified position;

• the gradient of the termination pipe shall be within 0.5° of the specified gradient; and

• the invert level at the termination face of the pipe shall be within 3 mm of the specified invert level.

6.5.11 Connections

(a) Connections to structures:

(i) The joints between pipes for drainage works and structures into which the pipes are built shall be watertight; protective coatings shall be removed over the length to be built in before the pipe is built in. Pipe collars and sockets shall not be built in to structures.

(ii) Two flexible joints shall be provided in pipelines adjacent to the outside

faces of structures into which pipes will be built. The distances from the outside face of the structure to the first joint and from the first joint to the second joint shall be as stated in Table 6.10.

(iii) The ends of pipes which are built in to structures shall be temporarily

sealed with a blank flange, brickwork or timber boarding. The temporary seals shall be left in position until the Project Manager permits their removal.


Table 6.10: Flexible Joints at Structures

Diameter of pipe Position of first flexible

joint from structure Distance of second flexible joint from first flexible joint Minimum Maximum

not exceeding 450 mm

150 mm 500 mm or

diameter of pipe, which-ever is less

450 mm - 800 mm exceeding 450 mm but not exceeding 1050 mm

900 mm - 1200 mm

exceeding 1050 mm

1500 mm - 1800 mm

(b) Connections to pipes:

(i) Pipe saddles shall be connected to concrete or vitrified clay pipes by bedding the saddle on a cement mortar bed and forming a cement mortar fillet to provide at least 50 mm cover to the base of the saddle. Cement mortar shall consist of cement and sand in the proportions 1:3 by mass.

(ii) UPVC pipe saddles shall be fixed to UPVC pipes using a purpose-made

mechanical clip or solvent cement of a type recommended by the manufacturer and reviewed without objection by the Project Manager.

(iii) Branch pipelines shall be connected to main pipelines using Y-junctions

of the same type and strength as the stronger of the pipes being jointed. The angle of the Y-junction shall be such that the angle between the direction of flow in the branch and main pipes shall be between 30° and 45°.

(iv) The positions of the pipe junctions relative to the manhole or structure

immediately downstream shall be measured and recorded before backfilling.

(v) The ends of connecting pipes not required for immediate use shall be

sealed with a blank flange or brickwork and the position measured and recorded before backfilling.

(vi) The Contractor shall allow for the existing flow of water when

connecting new sewers, drains and culverts to existing pipelines, culverts, manholes and other drainage chambers.

(vii) Prior to the connection to existing pipelines, culverts, manholes and

other drainage chambers the Contractor shall check the invert level of the existing drainage to which he has to connect and inform the Project Manager of any discrepancies between the actual level and the level specified on the Employer’s Drawings.


6.5.12 Manholes, Chambers, Gullies and Channels (a) Manholes, chambers and gullies:

(i) Bases, inverts and benching for precast concrete manholes shall be constructed in-situ using Grade 20 concrete, unless otherwise stated in the Contract.

(ii) Precast concrete units for manholes and chambers shall be set

vertically with step irons staggered and vertically aligned above each other. Joints between precast units shall be the rebated type and shall be sealed with cement mortar; lifting holes shall be filled with cement mortar. Surplus cement mortar shall be removed and joints shall be pointed.

(iii) Concrete surrounds to manholes, chambers and gullies shall be Grade

20 concrete. Joints in concrete surrounds shall be staggered by at least 150 mm from joints in the precast units. Concrete surrounds to gullies shall be placed up to the sides of the excavation.

(iv) The frames for manhole covers and gully gratings shall be set to the

same levels as the surrounding surface, allowing for falls and cambers, using brickwork and/or concrete. The number of courses of brickwork used below frames shall not exceed three and the minimum grade for concrete shall be Grade 20.

(v) Cement mortar for fixing manhole covers and gully gratings in position

and bonding brickwork shall consist of cement and sand in the proportions 1:3 by mass.

(vi) Excavations around manholes and chambers in carriageways shall be

filled using Grade 10 concrete up to the carriageway formation level. Fill material for excavations around other manholes and chambers shall be fine fill material.

(vii) Manholes, chambers and gullies shall be water tight on completion.

(b) Concrete open channels:

The top surfaces of side walls of concrete open channels shall be constructed to the same levels as the adjoining Permanent Works. Excess excavation beyond the channel walls shall be filled with Grade 10 concrete.

6.5.13 Marker Blocks

(a) The ends of pipes which do not terminate at a manhole, chamber, gully or

structure shall be marked with marker blocks. The blocks shall be 150 mm x 150 mm x 150 mm and shall be constructed using Grade 20 concrete.

(b) A wire shall be connected from a hook at the underside of the block to the

plug at the end of pipes.

(c) Marker blocks shall be set flush level with the adjacent Permanent Works and shall have the letters ‘CD’ marked on the upper surface.


6.5.14 Installation of Penstocks and Valves (a) Penstocks and valves shall be installed in accordance with the manufacturer's

recommendations and in the closed position.

(b) Frames for penstocks shall be fixed in position leaving a 20 mm gap between the frame and the concrete surface. Contact between the penstock door and frame shall be checked using a feeler gauge 0.1 mm thick or other size recommended by the manufacturer.

(c) Box-outs and rebates for penstock and valve frames and gaps between

frames and concrete surfaces shall be filled with cement mortar. (d) After installation, penstocks and valves shall be cleaned and moving parts

shall be lightly greased and checked for ease of operation. Penstocks and valves shall be left in a closed position.

6.5.15 Pipes and Manholes to be Abandoned

(a) Manholes, chambers and gullies which are to be abandoned shall be

demolished and removed unless otherwise stated in the Contract. Abandoned pipes, culverts, manholes, chambers and gullies shall be filled with foam concrete or grout, by pumping or by gravity. The lowest point of abandoned pipelines shall be sealed with concrete or bricks. Filling shall start from the lowest point and shall continue until all voids are completely filled.

(b) If the top of a pipe or culvert, or the bottom of a manhole, chamber or gully to

be abandoned is 1 m or less below the finished ground level, the pipe, manhole, chamber or gully shall be removed and disposed of by the Contractor. The void shall be filled with foam concrete, granular fill material or special fill material which has been reviewed without objection by the Project Manager.

(c) If the top of a pipe or culvert, or the bottom of a manhole, chamber or gully to

be abandoned is more than 1 m below the finished ground level, the pipe, culvert, manhole, chamber or gully shall be filled with foam concrete or grout as stated in Clause 6.3.25.

6.5.16 Cleaning of Pipelines

(a) Pipelines for drainage works shall be cleaned by pigging or by high pressure

water jetting; manholes and chambers shall be cleaned and washed. Cleaning shall be carried out:

(i) before and after the complete pipeline, or parts of the pipeline if

permitted by the Project Manager, have been tested; (ii) after the Temporary Works required for testing have been removed; and (iii) after parts of the pipeline removed for testing have been reconnected.

(b) Pipelines shall be cleaned not more than 7 days before the application for

Completion Certificate for the pipeline works is submitted.


6.5.17 Employment of Qualified Polyethylene Pipe Layers (a) A qualified polyethylene pipe layer shall mean a worker or supervisory staff

who has successfully completed the short course "Installation of Polyethylene Pipes" organized by Hong Kong Institute Vocational Education and passed the examination or equivalent.

(b) All connections or jointing of polyethylene pipe works must be carried out by

qualified polyethylene pipe layers. The Contractor shall employ sufficient number of qualified polyethylene pipe layers to suit the workload of polyethylene pipe works.

(c) The Contractor shall submit to the Project Manager within seven days a name

list and supporting document of the qualified polyethylene pipe layers employed after commencement of polyethylene pipe works.

(d) The Contractor shall keep records of the names and supporting documents of

the qualified polyethylene pipe layers employed and shall make such records available for inspection by the Project Manager when required.

(e) The Contractor shall demonstrate the competence of the qualified

polyethylene pipe layers by testing them periodically or whenever required by the Project Manager who may witness all such tests. The Contractor shall complete all necessary arrangements for the tests within seven days from the notification of the Project Manager. The pipe layers shall be required to carry out butt fusion, electrofusion and heat fusion saddle on site under the witness of the representatives of the Project Manager. If the Project Manager is not satisfied with the competence of the pipe layers, the pipe layers shall not be counted as qualified polyethylene pipe layers and shall be prohibited to carry out connections or jointing of polyethylene pipes works. The Contractor shall arrange further training for these pipe layers. These pipe layers shall be tested again after a minimum period of two months and counted as qualified polyethylene pipe layers if they pass the test. If the Project Manager is still not satisfied with the competence of these pipe layers, these pipe layers shall refresh their knowledge and techniques by successful completing another short course "Installation of Polyethylene Pipes" organized by the Hong Kong Institute Vocational Education or equivalent before further testing.

6.6 INSPECTION, TESTING AND COMMISSIONING

6.6.1 Testing of Pipelines (a) Inspection of pipelines

The cleanliness, bore, linearity and joints of pipelines of 450 mm diameter or less shall be checked by pulling a mandrel through the completed pipeline, or parts of the pipeline if permitted by the Project Manager, after cleaning. The mandrel shall be 750 mm long and 12 mm less in diameter than the nominal diameter of the pipe.


(b) Inspection of pipelines by CCTV

All pipelines shall be inspected internally by CCTV after cleaning in accordance with Clause 6.5.16. The procedure for internal inspection by CCTV shall be as stated in Appendix A6.1. The defects discovered by the CCTV inspection shall be rectified in accordance with Clause 6.6.8(b).

6.6.2 Testing of Pipes for Drainage Works

(a) Batch: pipes for drainage works

A batch of pipes or fittings for drainage works is any quantity of pipes or fittings of the same type and nominal diameter, manufactured by the same manufacturer, covered by the same certificates and delivered to the Site at any one time.

(b) Samples: pipes for drainage works

One sample of pipe for drainage works and each type of fitting shall be provided from each 50 pipes or fittings or part thereof in a batch.

(c) Testing: pipes for drainage works

(i) Each sample of pipes and fittings for drainage works shall be tested in accordance with the relevant British Standard.

(ii) The method of testing shall be in accordance with the following:

Concrete pipes and fittings : BS 5911: Part 100 Vitrified clay pipes, fittings and joints : BS 65 Ductile iron pipes and fittings : BS 4772 Grey iron pipes and fittings : BS 4622 UPVC pipes for industrial purposes : BS 3506 UPVC soil and ventilating pipes, fittings and accessories : BS 4514 UPVC rainwater goods : BS 4576:Part 1 UPVC underground drain pipes and fittings : BS 4660 Plastic waste pipes and fittings : BS 5255 UPVC pipes and fittings for gravity sewers : BS 5481

(d) Non-compliance: pipes for drainage works

(i) If the result of any test required in accordance with the relevant British Standard for pipes and fittings for drainage works does not comply with the specified requirements for the test, one additional sample shall be provided from the same batch and additional tests for the property shall be carried out.

(ii) The batch shall be considered as not complying with the specified

requirements for the property if the result of any additional test does not comply with the specified requirements for the property.


6.6.3 Testing of Aggregates for Granular Bed (a) Batch: aggregates for granular bed

A batch of aggregates for granular bed is any quantity of aggregates for granular bed of the same type, produced at the same time in the same place, covered by the same certificates and delivered to the Site at any one time.

(b) Samples: aggregates for granular bed

(i) One sample of aggregates for granular bed shall be provided from each batch of aggregates for granular bed delivered to the Site.

(ii) The size of each sample shall be 40 kg.

(iii) The method of sampling shall be in accordance with BS 812: Part 102.

(iv) The moisture content of the sample shall be representative of the

moisture content of the material in the batch. (c) Testing: aggregates for granular bed

Each sample of aggregates for granular shall be tested to determine the particle size distribution and ten percent fines value in accordance with BS 812:Part 103 and BS 812:Part 111, and the compaction fraction value in accordance with Appendix A6.2.

(d) Compliance criteria: compaction fraction value

The results of tests for compaction fraction value of aggregates for granular bed shall comply with the following requirements:

(i) The compaction fraction value for pipe bed not exceeding 300 mm

nominal diameter shall not exceed 0.3; and

(ii) The compaction fraction value for pipe bed exceeding 300 mm nominal diameter shall not exceed 0.15.

6.6.4 Testing of Precast Concrete Units for Manholes, Chambers and Gullies (a) Batch: manholes, chambers and gullies

A batch of precast concrete units for manholes, chambers or gullies is any quantity of precast concrete units for manholes, chambers or gullies of the same type and size, manufactured by the same manufacturer, covered by the same certificates and delivered to the Site at any one time.

(b) Samples: manholes, chambers and gullies

One sample of precast units for manholes, chambers or gullies shall be provided from each batch of 50 precast concrete units for manholes, chambers or gullies or part thereof delivered to the Site.


(c) Testing: manholes, chambers and gullies

(i) Each sample of precast concrete units for manholes, chambers or gullies shall be tested in accordance with the relevant British Standard.


Precast concrete units for manholes : BS 5911: Part 200 Inspection chambers and gullies : BS 5911: Part 2.

(d) Non-compliance: manholes, chambers and gullies

(i) If the result of any test required in accordance with the relevant British Standard for precast concrete units for manholes, chambers or gullies does not comply with the specified requirements for the test, one additional sample shall be provided from the same batch and additional tests for the property shall be carried out.



6.6.5 Testing of Manhole Covers, Gully Gratings and Kerb Overflow Weirs

(a) Batch: covers, gratings and weirs

A batch of manhole covers, gully gratings or kerb overflow weirs is any quantity of covers, gratings or weirs of the same type, manufactured by the same manufacturer, covered by the same certificates and delivered to the Site at any one time.

(b) Samples: covers, gratings and weirs

One sample of manhole covers, gully gratings or kerb overflow weirs shall be provided from each batch of 20 covers, gratings or weirs or part thereof delivered to Site.

(c) Testing: covers, gratings and weirs

(i) Each sample of manhole covers, gully gratings or kerb overflow weirs shall be weighed to determine the mass, a load test shall be carried out on each sample of covering and grating to determine the resistance to fracture.

(ii) The method of testing shall be as stated in Appendix A6.3. The test

loads shall be as stated in Table 6.6 and Table 6.7. (d) Compliance criterion: resistance to fracture of covers and gratings

Manhole covers and gully gratings shall withstand the test load without fracture or cracking.


(e) Non-compliance: mass of covers, gratings and weirs

(i) If the result of any test for mass of any manhole cover, gully grating or kerb overflow weir does not comply with the specified requirements for mass, every cover, grating and frame in the batch shall be weighed to determine its mass.

(ii) If any cover, grating or weir does not comply with the specified

requirements for mass, it shall not be used in the Permanent Works. (f) Non-compliance: resistance to fracture of covers and gratings

(i) If any manhole cover or gully grating does not comply with the specified requirements for resistance to fracture, two additional samples shall be provided from the same batch and tested to determine their resistance to fracture.


requirements for resistance to fracture if the result of either additional test does not comply with the specified requirements for resistance to fracture.

6.6.6 Testing of Watertightness of Penstocks

(a) Testing: watertightness of penstocks

(i) Penstocks shall be tested for watertightness after installation by applying pressure using a head of water applied to one face of the penstock and no head of water on the other face. The test pressure and the face on which the pressure is to be applied shall be as stated in the Contract.

(ii) The method of testing shall be as submitted for review without objection

by the Project Manager.

(iii) The test pressure shall be maintained for 24 hours. (b) Compliance criteria: watertightness of penstocks

The results of tests for watertightness of penstocks shall comply with the following requirements:

(i) there shall be no leaks through the penstock during the test; and

(ii) there shall be no leaks or damp patches visible at the joint between the

penstock and the structure during the test. (c) Non-compliance: watertightness of penstocks

If the result of any test for watertightness of penstocks does not comply with the specified requirements for the test, the Contractor shall investigate the reason. Remedial or replacement work reviewed without objection by the Project Manager shall be carried out and the penstock shall be re-tested.


6.6.7 Testing of Gravity Pipelines for Drainage Works (a) Gravity pipelines for drainage works shall be tested as stated in Clause

6.6.7.(b) to (h).

(b) Gravity pipelines for sewage shall be tested by the methods stated in Table 6.11 at the following times:

(i) after the pipes have been jointed and the bedding has been placed and

immediately before haunch or surround is placed or fill material is deposited;

(ii) after haunch and surround has been placed and fill material has been

deposited and compacted; and

(iii) not more than 7 days before a Completion Certificate for the pipeline works is applied for.

(c) Gravity pipelines for surface water shall be tested by the methods stated in

Table 6.11 at the following times:

(i) after the pipes have been jointed and the bedding has been placed and immediately before haunch or surround is placed or fill material is deposited; and


deposited and compacted. (d) Water tests and air tests on pipelines shall be carried out on the complete

pipeline between manholes, chambers and structures; pipelines shall not be tested in parts unless the specified test pressure will be exceeded. Short branch pipelines shall be tested with the main pipeline and long branch pipelines shall be tested separately.

(e) Infiltration tests shall be carried out on the complete pipeline between

manholes, chambers and structures, including manholes, chambers and branches within the pipeline system.

(f) The method of testing shall be in accordance with Appendix A6.4. (g) Visual inspections shall be carried out on the complete pipeline between

manholes, chambers and structures. (h) Visual inspections shall be carried out by the Contractor in the presence of the

Project Manager.


Table 6.11: Testing Gravity Pipelines Type of pipeline

Diameter of pipeline

Time of test

Method of testing

Sewage not exceeding 300 mm

as Clause 6.6.7(b) Water test

Sewage not exceeding as Clause 6.6.7(b)(i) Water test or air test 900 mm as Clause 6.6.7(b)(ii) Water test or air test as Clause 6.6.7(b)(iii) Infiltration test Sewage exceeding as Clause 6.6.7(b)(i) Visual inspection 900 mm as Clause 6.6.7(b)(ii) Water test or air test as Clause6.6.7(b)(iii) Infiltration test Surface Water

not exceeding 300 mm

as Clause 6.6.7(c) Water test

Surface not exceeding as Clause 6.6.7(c)(i) water 900 mm Or

as Clause 6.6.7(c)(ii) Water test or air test

Surface exceeding As Clause 6.6.7(c)(i) Visual inspection water 900 mm as Clause 6.6.7(c)(ii) Water test or air test

6.6.8 Compliance criteria: gravity pipelines for drainage works

(a) The results of tests on gravity pipelines for drainage works shall comply with

the following requirements:

(i) the leakage of water from the pipeline determined by the water test shall not exceed the permitted leakage calculated in accordance with Clause A6.4.8 of Appendix A6.4;

(ii) there shall be no discernable leakage from the pipe or from any joint

during the water test;

(iii) the air pressure shall remain above 75 mm head of water at the end of the air test; and

(iv) there shall be no infiltration or damage to pipes or joints as determined

by the visual inspection. (b) The Contractor shall investigate the reason for any non compliance.

Remedial or replacement work reviewed without objection by the Project Manager shall be carried out and the pipeline shall be re-tested.


6.6.9 Testing of pressure pipelines for drainage works (a) Pressure pipelines for drainage works shall be tested as stated in Clause

6.6.9(b) to (g).

(b) The pipeline shall be tested at the following times:

(i) after the pipes have been jointed and the bedding has been placed and immediately before haunch or surround is placed or fill material is deposited; and


deposited and compacted for the complete pipeline.

(c) The test stated in Clause 6.6.9(b)(i) shall not be carried out on parts of a pipeline unless permitted by the Project Manager. The test stated in Clause 6.6.9(b)(ii) shall be carried out on the complete pipeline.

(d) The test pressure shall be as stated in the Contract. If the test pressure is not

stated in the Contract, the test pressure shall be 1.5 times the maximum working pressure in the part of the pipeline tested.

(e) Tests shall not be carried out simultaneously on more than one pipeline in the same trench.

(f) The method of testing shall be in accordance with Appendix A6.5.

(g) Testing of pressure pipelines by means of tests on individual joints shall not be carried out instead of tests stated in Clause 6.6.9(b) to (f).

6.6.10 Compliance criteria: pressure pipelines for drainage works

(a) The results of tests on pressure pipelines for drainage works shall comply with

the following requirements:

(i) The leakage of water from the pipeline determined by the pressure test shall not exceed the permitted leakage calculated in accordance with Clause A6.5.4 of Appendix A6.5.

(ii) There shall be no discernable leakage of water from the pipeline or from

any joint during the pressure test. (b) If the result of any test on pressure pipelines for drainage works does not

comply with the specified requirements for the test, the Contractor shall investigate the reason. Remedial or replacement work reviewed without objection by the Project Manager shall be carried out and the pipeline shall be re-tested.


APPENDIX A6.1

CCTV INSPECTION OF PIPELINES A6.1.1 Scope

This method covers the internal inspection of pipelines by means of closed circuit television. (CCTV)

A6.1.2 Equipment (1) The equipment specified in Clauses A6.1.2(l) (a) to (g) shall be provided:

(a) A CCTV colour camera with integral lighting unit. The camera shall be a type designed and constructed for the specified purpose and shall be capable of operating in 100% relative humidity. The camera shall be fitted with a rotating mirror for complete circumferential viewing. The system shall be capable of producing a clear and high quality picture of the entire periphery of the pipe on the monitor screen and recording tape. The camera and lighting unit shall be mounted on a self-propelled crawler or on skids linked to a manual or power operated winch.

(b) A monitor screen which displays the camera view during the inspection.

The monitor screen shall be housed in covered accommodation with facilities for inspection by the Project Manager and others.

(c) A screen writer which displays on the monitor screen details of the

inspection including date, location, pipe material, diameter of pipe, direction of view and comments on the condition of the pipe.

(d) A linear measuring device which displays the chainage of the camera

position automatically on the monitor screen. The device shall be capable of measuring the chainage to within an accuracy of 0.1% of the length of the pipeline or ±0.3 m whichever is the greater.

(e) A control unit which controls camera movement, lighting intensity,

focusing and recording by a video system. (f) A VHS video recording system to record the inspection and information

displayed on the monitor screen.

(g) A 35 mm single lens reflex (SLR) camera capable of producing photographs with details of the date.


A6.1.3 Procedure (1) The procedure shall be as specified in Clause A6.1.3 (1) (a) – (d)

(a) The camera shall be moved through the pipeline in the direction directed by the Project Manager at a speed not exceeding 0.15 m/s. If the camera cannot pass through the complete pipeline in one operation, the inspection shall be carried out from both ends of the pipeline.

(b) The camera shall be stopped whenever directed by the Project Manager

to allow inspection by the Project Manager. (c) The video system shall be operated during the complete inspection to

provide a continuous record of the inspection and information on the monitor screen.

(d) Photographs of the monitor screen shall be taken whenever required by

the Project Manager.

A6.1.4 Recording of Results

(1) Records of the inspections shall be kept by the Contractor on the Site and a report shall be submitted to the Project Manager for review within 14 days of completion of the inspection. The report shall contain the following details:

(a) key map showing pipelines inspected and associated manholes,

chambers and structures, (b) tables listing details of inspection, including date, location, pipe material,

diameter of pipe, chainage, manholes, junctions and other features and the condition of pipes and joints; the condition of pipes and joints shall be illustrated by a coding systems in accordance with the `Manual of Sewer Condition Classification' (1980) published by the U.K. National Water Council, and

(c) a summary showing the number and type of defects in each pipeline

inspected. (2) The following items shall be submitted at the same time as the report:

(a) video film providing a continuous record of the inspection and information on the monitor screen together with an index showing the location on the video tape of commencement of each pipe inspection; and

(b) photographs of the monitor screen including date and chainage; the

photographs shall be 3R size and shall be mounted in photograph albums.


APPENDIX A6.2

DETERMINATION OF THE COMPACTION FRACTION VALUE OF AGGREGATES FOR GRANULAR BED

A6.2.1 Scope

This method covers the determination of the compaction fraction value of aggregates for granular bed.

A6.2.2 Apparatus

The following equipment shall be provided:

(1) a steel open-ended cylinder, 150 mm internal diameter by 250 mm high, with a wall thickness of not less than 3.5 mm;

(2) a steel rammer of 40 mm diameter weighing approximately 1 kg; and (3) a steel rule calibrated to 1 mm.

A6.2.3 Procedure

(1) The procedure shall be as described in Clauses A6.2.5 (1) (a) – (e)

(a) The sample shall be placed on a clean surface and shall be divided by quartering or by using a riffle box to obtain a specimen weighing approximately 10 kg.

(b) The cylinder shall be placed on a firm level surface and shall be filled

without tamping with material taken from the sample. Surplus material shall be struck off level with the top of the cylinder, and cleared from the area around the cylinder.

(c) The cylinder shall be lifted clear of the contents and placed alongside

the material. (d) Approximately one quarter of the material shall be placed in the cylinder

and compacted using the rammer until no further compaction can be achieved. The procedure shall be repeated for each of the remaining three quarters of the material. The top surface shall be compacted as level as practicable.

(e) The distance (d) from the top of the cylinder to the top surface of the

material shall be measured to the nearest 1 mm.


A6.2.4 Calculation

The compaction fraction value of the material shall be calculated from the equation: Compaction fraction value = d/h where: - d is the distance from the top of the cylinder to the top surface of the material

(mm), - h is the height of the cylinder (mm).

A6.2.5 Reporting of Results

The following shall be included in the report submitted to the Project Manager:

(1) identification of sample; (2) compaction fraction value to the nearest 0.01; (3) source and type of material; (4) date of test; and (5) statement that the test method used was in accordance with this General

Materials and Workmanship Specification.


APPENDIX A6.3

DETERMINATION OF THE RESISTANCE TO FRACTURE OF MANHOLE COVERS AND GULLY GRATINGS

A6.3.1 Scope

This method covers the determination of the resistance to fracture of manhole covers and gully gratings by means of a load test.

A6.3.2 Equipment


(1) manufacturer's recommended test frame for the manhole cover or gully grating or a fabricated test frame of a type reviewed without objection by the Project Manager which will simulate the normal conditions of use of the cover or grating;

(2) circular hardwood bearing block faced with hard rubber or other resilient

material. The diameter of the block shall be as stated in Table 6.6 or Table 6.7 for the relevant cover or grating. The block shall be sufficiently rigid to ensure that the load is equally distributed over the whole area of the block;

(3) test loads; and (4) equipment for measuring the loads applied, readable and accurate to 0.05 t or

2% of the specified test load, whichever is greater. A6.3.3 Procedure

The procedure shall be as follows:

(1) the full bearing area of the frame shall be rigidly supported; (2) the cover or grating shall be placed in the frame. The bearing block shall be

placed centrally on the cover or grating; (3) the specified test load as stated in Table 6.6 and 6.7 shall be applied without

shock; and (4) the specified test load shall be maintained for at least 30 seconds and

removed. A6.3.4 Reporting of Results The following shall be induced in the report submitted to the Project Manager:

(1) identification of sample; (2) the load applied, to the nearest 0.05 t or 2% of the specified test load,

whichever is greater; (3) details of any fracture or cracks; and (4) statement that the test method used was in accordance with this General



APPENDIX A6.4

TESTS ON GRAVITY PIPELINES FOR DRAINAGE WORKS

A6.4.1 Scope This method covers water tests, air tests, visual inspections and infiltration tests on

gravity pipelines for drainage works. A6.4.2 Equipment The following equipment shall be provided:

(1) expanding disc stoppers or air bags for sealing pipes; (2) struts and wedges; (3) force pump for water test; (4) standpipe for water test; (5) measuring vessel for water test, readable and accurate to 0.01 litre; (6) U-tube for air test; and (7) trolleys to obtain access inside pipelines for visual inspections. Mechanical

fans shall be provided to ensure that an adequate air supply is available; internal combustion engine driven fans shall be fitted with a flexible exhaust or other methods of keeping exhaust fumes clear of the fresh air intake.

A6.4.3 Procedure: before Tests and Inspections The procedure before tests and inspections shall be as follows:

(1) debris and water shall be removed from the pipeline; and (2) openings to the pipeline shall be sealed using expanding disc stoppers or air

bags and the seals secured against movement. A6.4.4 Procedure: Water Test The procedure for the water test shall be as follows:

(1) the pipeline shall be filled with water and shall be kept filled for two hours before testing starts to allow absorption to take place;

(2) test pressure of 1.2 m head of water above the soffit of the pipe at the high

end shall be applied at the standpipe and maintained for 30 minutes; the test pressure applied shall not exceed 6 m head of water at the invert of the low end of the pipe;

(3) the head of water at the standpipe shall be topped up at 5 minute intervals

during the test, and shall be filled to the specified head at the end of the test period; the amounts of water added to the standpipe shall be measured using the measuring vessel; and


(4) the leakage of water from the pipeline shall be measured as the amount of water added to maintain the specified head of water.

A6.4.5 Procedure: Air Test

The procedure for the air test shall be as follows:

(1) air shall be pumped into the pipeline until a test pressure of slightly more than

100 mm of water is registered on a U-tube manometer connected to the pipeline. Five minutes shall be allowed for stabilisation of the air temperature, and the air pressure shall then be adjusted to 100 mm of water; and

(2) the pressure shall be read from the U-tube at the end of a five-minute period

without further pumping.

A6.4.6 Procedure: Visual Inspection

The inside of the pipeline shall be inspected visually, and infiltration or damage to pipes or joints shall be recorded.

A6.4.7 Procedure: Infiltration Test

The procedure for the infiltration test shall be in accordance with BS 8005: Part 1

Clause 13.6.

A6.4.8 Calculation

The permitted leakage of water from the pipeline during the water test shall be calculated from the equation:

Permitted leakage = d x 1 x t x P litre 60

where: - d is the internal diameter of the pipe (m), - l is the length of pipeline tested (m), - t is the test period (min), - P is the average test pressure (m).


The following shall be included in the report submitted to the Project Manager:

(1) nominal internal diameter of the pipe to the nearest 1 mm; (2) location and length of pipeline tested to the nearest 0.3 m; (3) test pressure applied during the water test to the nearest 0.01 m, and during

the air test to the nearest 1 mm head of water; (4) test period to the nearest 1 min; (5) leakage and permitted leakage for the water test to the nearest 0.1 litre;


(6) amount of infiltration and permitted amount of infiltration for the infiltration test to the nearest 0.1 litre;

(7) details of any discernable leakage of water from the pipe or from any joint

during the water test; and (8) statement that the test method used was in accordance with this General



APPENDIX A6.5

TESTS ON PRESSURE PIPELINES FOR DRAINAGE WORKS

A6.5.1 Scope

This method covers the determination of the leakage of water from pressure pipelines for drainage works by means of a pressure test.

A6.5.2 Equipment


(1) blank flanges or caps; (2) struts and wedges; (3) temporary concrete blocks or other anchors; (4) force pump; (5) pressure gauge, readable and accurate to 0.01 m head of water. The gauge

shall be either a conventional circular type of at least 300 mm diameter or shall be a digital indicator type; and

(6) measuring vessel, readable and accurate to 0.01 litre.

A6.5.3 Procedure


(1) pipes and valves shall be cleaned and the operation of valves shall be

checked. Air valves shall be isolated. (2) blank flanges or caps shall be fixed to the ends of the pipeline, or part of the

pipeline, to be tested. Tests shall not be made against closed valves. (3) the blank flanges and caps and closed valves against which tests are made

shall be secured with struts and wedges against temporary concrete blocks or other anchors. The blocks shall be completed and shall have hardened sufficiently before testing starts. Thrust and anchor blocks, pipe straps and other devices required to prevent movement of pipes and fittings shall be completed before testing starts.

(4) the pipeline shall be filled with water and all air shall be removed; measures

shall be taken during filling to provide free outlets for air and to prevent water hammer.

(5) the pressure in the pipeline shall be increased to working pressure and the

pipeline shall remain filled at this pressure for 2 hours to allow absorption to take place and to achieve conditions which are as stable as practicable.

(6) the pressure in the pipeline shall be increased slowly by pumping water into

the pipeline using a force pump until the specified test pressure is reached at the lowest part of the pipeline being tested.


(7) the pressure in the pipeline shall be maintained at the specified test pressure, using the force pump if necessary, for a period of at least 1 hour.

(8) at the end of the 1 hour period the pressure shall be increased, if necessary,

to the specified test pressure and pumps and water supply points shall be disconnected.

(9) the pipeline shall be left in this condition for a test period of 1 hour; no water

shall be allowed to enter the pipeline during the test period. (10) at the end of the test period the pressure in the pipeline shall be recorded. (11) the pumps and water supply points shall be reconnected and the pressure

shall be increased to the specified test pressure. (12) water shall be drawn off from the pipeline until the pressure in the pipeline is

the same as at the end of the test period. The leakage of water from the pipeline shall be measured as the amount of water drawn off.

A6.5.4 Calculation

(1) The average test pressure (P) shall be calculated as the average of the specified test Pressure and the pressure at the end of the test period.

(2) The permitted leakage of water from the pipeline during the pressure test shall

be calculated from the equation:

Permitted leakage = d x 1 x t x P litre 12 where:

- d is the nominal internal diameter of the pipe (m), - l is the length of pipeline tested (km), - t is the test period (hr), - P is the average test pressure (m).

A6.5.5 Reporting of Results The following shall be included in the report submitted to the Project Manager:

(1) the nominal internal diameter of the pipe; (2) the location and length of pipeline tested to the nearest 0.3 m; (3) the test period to the nearest one minute; (4) the specified test pressure to the nearest 0.01 m head of water; (5) the pressure at the end of the test period to the nearest 0.01 m head of water; (6) the average test pressure to the nearest 0.01 m head of water;


(7) leakage and permitted leakage to the nearest 0.1 litre; (8) details of any discernable leakage of water from the pipeline during the test;

and (9) that the test method used was in accordance with this General Materials and

Workmanship Specification.


APPENDIX A6.6

SPECIFICATION FOR POLYETHYLENE PIPES AND FITTINGS 1. General

1.1 The manufacturer for the supply of polyethylene pipes and fittings shall operate a quality system relating to the relevant part(s) of the specification stated hereunder in accordance with BS EN ISO 9002 or similar equivalent standard. The manufacturer's quality assurance certificates issued by an independent third party certification body shall be submitted to the Project Manager for review without objection. Such certificates shall be valid at the time the pipes and fittings are manufactured.

1.2 Polyethylene pipes and fittings shall be used aboveground for the

conveyance of sewage discharge.

2. Definitions

2.1 Nominal outside diameter of a polyethylene pipe shall mean the minimum mean outside diameter of the pipe as described in Clause 3.1 of IS0 16 1-1.

2.2 Nominal wall thickness of a polyethylene pipe shall mean the minimum wall

thickness of the pipe as described in Clause 3.4.5 of BS IS0 11922-1. 2.3 The Standard Dimension Ratio (SDR) of a polyethylene pipe shall mean the

ratio of its nominal outside diameter to its nominal wall thickness as described in Clause 3.8 of IS0 161-1.

2.4 WIS shall mean the Water Industry Specification produced and published by WRc.

3. Polyethylene Pipes

3.1 PE80 and PE 100 pipes with nominal outside diameter from 90mm to 1000mm inclusive shall conform to IS0 4427.

3.2 PE80 and PE100 pipes shall have a SDR of 17.6 and have nominal pressure

rating as follows: PEl00 - 10 bar (PNl0)

3.3 The colour for polyethylene pipes shall be black within the range below:

Nominal Outside Diameter

Colour Range

90mm – 1000mm 20D44 to 20D45 or 20E53 to 20E56 of BS 5252

3.4 The tolerance on the nominal outside diameter of polyethylene pipes shall be

in accordance with Grade B of BS ISO 11922-1.


3.5 The end of the pipe shall be cut cleanly and square to the axis of the pipe to within the tolerances given below:

Nominal Outside Diameter

Maximum Tolerance (mm)

125mm 3

180mm or above 4

3.6 Standard length of polyethylene pipes shall be 5m. No reduction in the specified length shall be allowed unless reviewed without objection by the Project Manager.

3.7 Melt flow rate of PE80 and PE 100 pipes tested at a temperature of 190°C

under a nominal load of 5kg shall be within the range of 0.2g/10 min to 1.3g/10 min.

4. Fittings for Polyethylene pipes

4.1 All fittings for polyethylene pipes shall have a pressure rating the same as or higher than the nominal pressure rating of the pipes. The fittings shall be supplied with complete set of accessories including insert, liners, joint rings, flange gaskets, studs, bolts and nuts, etc. whatever appropriate.

4.2 The flanges of all fittings shall be constructed in such a way that they may be attached to flanges designated PN16 whose dimensions conform to Table 9 of BS EN 1092-2. One complete set of bolts and nuts and one gasket shall be supplied with each flange of flanged fittings. The strength of bolts shall be Grade 4.8 and the strength of nuts shall be Grade 4 complying with BS 4190. The bolts and nuts shall be hot dip galvanized or have other protective coatings reviewed without objection by the Project Manager.

4.3 Polyethylene Electrofusion Fittings

4.3.1 Polyethylene electrofusion fittings including couplers, reducers, socket ends

tees, caps and elbows, self tapping tee saddles and other electrofusion fittings shall comply with WIS 4-32-14. Polyethylene spigot fittings for electrofusion jointing including the spigot stub flange assembly shall comply with WIS 4-32-15. Stub flanges shall comply with WIS 4-24-01.

4.3.2 Melt flow rate of PE80 and PE100 electrofusion fittings tested at a

temperature of 190°C under a nominal load of 5kg shall be within the range of 0.2g/10 min to 1.3g/10 min.

4.3.3 Notwithstanding Clause 5.1.6 of WIS 4-32-14, the fittings shall be capable of

being fused in the tropics. 4.3.4 The design of fitting terminals and shrouds shall be similar to that stated in

Clause 5.2.3 of WIS 4-32-14. Other designs of terminals will only be considered if the Contractor can demonstrate that the appropriate lead adaptor is readily available such that electrofusion of their fittings can be conducted using common electrofusion control units available in the market.

4.3.5 All electrofusion fittings shall be black in colour within the range as specified

in Clause 3.3 of this Appendix A6.6.


4.4 Compression Fittings for Polyethylene Pipes

4.4.1 Compression fittings with external and/or internal threads shall be compatible with pipes and fittings threaded to BS 21.

4.5 Mechanical Fittings for Polyethylene Pipes

4.5.1 Mechanical fittings for polyethylene pipes of nominal outside diameter 90mm

and above shall be Type 1 fittings conforming to WIS 4-24-01. 4.5.2 Mechanical fittings shall be coated with a minimum thickness of 250 microns

of epoxy or plastic based coating complying with the performance requirement of WIS 4-52-01.

5. Samples and Submissions

5.1 A sample for each of the polyethylene pipes and fittings supplied shall be submitted to the Project Manager for review without objection before placing material order.

5.2 If required, a copy of the latest Manufacturer's type test reports required

under each of the above ISO and WIS shall be submitted to the Project Manager for information.

5.3 For all non-metallic components of the polyethylene pipes and fittings including coatings, certificates issued by an independent testing laboratory/inspection authority showing compliance with BS 6920 shall be submitted to the Project Manager for review without objection.

6. Markings

6.1 Markings on the polyethylene pipes and fittings shall be in accordance with the relevant clauses in the ISO or WIS appropriate to the pipes and fittings supplied.

6.2 Notwithstanding Clause 8 of ISO 4427, the pipes series in SDR shall be

marked on the pipes.

6.3 Notwithstanding Clause 10 of ISO 14236, the designation of the material (PE80 or PE100) and the number "ISO 14236" shall also be marked on the compression fittings.

7. Packaging of Fittings

7.1 All fittings (including electrofusion fittings) shall be delivered ex-factory together with all accessories such as bolts, ,nuts, washers, inserts, compression rings, gaskets and other things necessary for the completion of the joint in a complete set inside a separate polythene bag or equivalent packaging.


8. Testing and Inspection

8.1 The quality control tests listed in the following clauses of WIS shall be subject to inspection by an independent inspection agent: (a) Clause 5 of WIS 4-24-01 (b) Clause 7 of WIS 4-32-15 (c) Clauses 5.1.2 and 8 of WIS 4-32-14

8.2 For quality control on manufacturing of the pipes, the following tests listed in

ISO 4427 shall be subject to inspection by an independent inspection agent: (a) Clause 3.3 (b) Clause 3.7 - melt flow rate test only (c) Clauses 4.1 and 4.2 (d) Clause 5.1 - 100 hour at 20°C and 165 hour at 80°C only (e) Clause 6.3 b)

In addition, the internal and external surfaces of the pipes shall be smooth and free from defects which might otherwise impair their performance in service.

8.3 For quality control on manufacturing of the compression fittings, the following

tests listed in ISO 14236 shall be subject to inspection by an independent inspection agent:

(a) Clause 6.1 (b) Clauses 8.3.4.2 and 8.3.4.3

8.4 Polyethylene materials for both PE80 and PE100 shall be tested in

accordance with the Chlorine Water Test specified in Clause 9.8 of the Japanese Industrial Standard (JIS) K6762 and the performance of the polyethylene materials shall comply with the chlorine-water resistance for single wall pipe specified in Clause 5 of the JIS K6762. Test certificates shall be submitted to the Project Manager for review without objection.

General Materials & Workmanship Specification 1/37 January 2011 Issue No. 5, Volume 1 - Civil & Structural Works Section 7 - Earthworks

SECTION 7 EARTHWORKS 7.1 DEFINITIONS AND ABBREVIATIONS 7.1.1 Areas of Fill Areas of fill are areas within the Site, including areas in embankments, platforms

and slopes and in excavations for structures, pits and trenches, in which fill material is deposited and compacted as part of the Permanent Works.

7.1.2 Earthworks Final Surface and Formation “Earthworks final surface” is the surface to which the work included in Section 7 is

finished. “Formation” is that part of the earthworks final surface on which a pavement, structure or utility, is constructed, or on which the blinding or bedding for a pavement, structure or utility is placed.

7.1.3 Earthworks Material Earthworks material may consist of soil, rock, crushed concrete or crushed inert

demolition material which is on or below the Site at the commencement of the Contract, or which is imported to the Site to carry out the Works.

7.1.4 Topsoil “Topsoil” shall mean the surface material which contains humus and supports

vegetation. 7.1.5 Rock, Boulders and Materials other than Rock “Rock” shall mean all naturally occurring hard strata which would normally be

removed by blasting, by ripping, by chemical, gas or mechanical bursting agents, by hydraulic breaker, by pneumatic drills or by wedges and sledge hammers if removed by hand.

Boulders are isolated volumes of Rock which exceed 0.2m³ and are contained in a

matrix of “Material other than Rock”. “Material other than Rock” shall mean material which cannot be classified as

Topsoil or Rock. 7.1.6 Public Fill Public fill shall mean the inert material arising from construction and demolition

activities such as site clearance, excavation, construction, refurbishment, renovation, demolition and roadworks. Public fill comprises material including stone, rock, masonry, brick, concrete, soil and other inert material. There is no size limitation on the public fill, and a small amount of timber mixed with otherwise suitable material is permissible. The public fill may also consist of wet soil.


7.2 MATERIALS 7.2.1 Fill Material

(a) Fill material, other than public fill, shall consist of naturally occurring or processed material which at the time of deposition is capable of being compacted in accordance with the specified requirements to form stable areas of fill.

(b) Fill material shall not contain any of the following:

(i) material susceptible to volume change, including marine mud soil with a liquid limit exceeding 65% or a plasiticity index exceeding 35%, swelling clays and collapsible soils;

(ii) peat, vegetation, timber, organic, soluble or perishable material; (iii) dangerous or toxic material or material susceptible to combustion; (iv) metal, rubber, plastic or synthetic material; (v) material susceptible to volume change, marine mud or material from

swamps; or

(vi) other environmentally unacceptable contaminants.

(c) The different types of fill material shall have the particle size distributions within the ranges stated in Table 7.1.

(d) Special fill material shall consist of material which has a liquid limit not

exceeding 45%, a plasticity index not exceeding 20% and a coefficient of uniformity exceeding 50.

(e) Granular fill material shall consist of clean, hard, durable material. (f) Rock fill material shall consist of pieces of hard, durable rock of which not

more than 30% by mass is discoloured or shows other evidence of decomposition. Crushed rock or crushed concrete may be permitted subject to review without objection by the Project Manager.

(g) The Contractor will not be permitted to erect a crushing plant under the Contact. (h) The soluble sulphate content of fill material placed within 500 mm of concrete,

cement bound material or cementitious material shall not exceed 1.9 grams of sulphate, expressed as SO3, per litre.

(i) The total sulphate content, expressed as SO3, of fill material placed within

500 mm of metalwork shall not exceed 0.5% by mass.

(j) The use of public fill as fill material for earthworks shall only be permitted if the fill material complies with the particular requirements stated in the Contract and is reviewed without objection by the Project Manager.


(k) Well-graded material shall consist of material which has a coefficient of uniformity exceeding 10.

(l) Uniform-graded material shall consist of material which has a coefficient of

uniformity of 10 or less.

Table 7.1: Particle Size Distributions of Fill Material

Type of fill material Percentage by mass passing

Size BS test sieve 400 mm 200 mm 75 mm 20 mm 600 mm 63 mm

Fine fill material - - 100 - - -

General fill material - 100 75 - 100 - - -

Special fill material - - 100 - - 0 - 45

Granular fill material - - 100 - 0 - 5 -

Rock fill material (Grade 200) - 100 20 - 75 0 - 50 - -

Rock fill material (Grade 400) 100 20 - 75 10 - 30 0 - 25 - -

7.3 SUBMISSIONS 7.3.1 Particulars of Earthworks

(a) The following particulars of the proposed materials and methods of construction for earthworks shall be submitted to the Project Manager for review without objection:

(i) details of Contractor's Equipment and haulage vehicles;

(ii) methods of excavation and of deposition and compaction of fill material;

(iii) use of different types of excavated material and sources of imported fill

material;

(iv) arrangements for stockpiling excavated material and fill material and for disposing of earthworks material;

(v) methods of controlling the moisture content of fill material;

(vi) methods of controlling surface water and groundwater and of protecting

earthworks and earthworks material from damage due to water and from weather conditions which may affect the earthworks or earthworks material;

(vii) types of instrumentation and methods of monitoring groundwater levels;

(viii) types of instrumentation and methods of monitoring the ground and

structures for movements;


(ix) methods of dealing with existing water courses so as to maintain existing drainage path; and

(x) any special methods/sequence of work for earthworks adjacent to

structures.

(b) Where the Contractor proposes to form temporary slopes or proposes any form of temporary support to earthworks, then he shall submit full supporting calculations and the provisions of Section 2 of this General Materials and Workmanship Specification shall apply.

7.4 WORKMANSHIP 7.4.1 Ownership of Earthworks Material

(a) Earthworks material within the Site at the commencement of the Contract

shall remain the property of the Employer except as stated in Clause 7.4.1(b). (b) Earthworks material which is required to be disposed of by the Contractor

shall become the property of the Contractor when it is removed from the Site and shall be disposed of in accordance with the Employer’s guidelines for disposal of construction waste and Section 7 of the General Specification.

7.4.2 Temporary Works for Earthworks

The Contractor shall be fully responsible for the design, installation, dismantling and removal of all temporary supporting systems for earthworks. The Contractor shall submit to the Project Manager for review without objection the full supporting calculations for any proposed temporary slopes or any form of temporary support to earthworks and the provisions of Section 2 of this General Materials and Workmanship Specification shall apply.

7.4.3 Temporary Access and Drainage

The Contractor shall provide and maintain temporary access roads and temporary drainage and shall divert and reinstate permanent drainage systems. Temporary access roads shall be provided with drainage ditches over their full length. Details of any such temporary works shall be submitted to the Project Manager and his consent in writing shall be obtained before construction commences.

7.4.4 Handling and Storage of Earthworks Material

(a) Earthworks material shall not be handled or stored in a manner which will result in segregation, deterioration, erosion or instability of the material.

(b) Different types of earthworks material shall be kept separate from each other.

Earthworks material which is suitable for use as fill material shall be maintained in a suitable condition and shall not be contaminated.


7.4.5 Protection from Water and Weather and Protection of Existing Instruments

(a) Earthworks after site clearance, excavation or filling and earthworks material after excavation shall be kept free from water and shall be protected from damage due to water and from exposure to weather conditions which may affect the earthworks or earthworks material. The measures to be taken shall include the following:

(i) all safety measures stated in the Contract;

(ii) surfaces shall be maintained in a stable condition and shall be formed to

falls to shed water and to prevent ponding;

(iii) the area of exposed surfaces shall be kept to a minimum;

(iv) surface water flowing into the Site and within the Site shall be intercepted and diverted from the Site to a suitable discharge point;

(v) at each intersection and abrupt change of direction of surface drainage

channels an accessible catchpit shall be provided;

(vi) all drainage works shall be kept clear of debris and silt; and

(vii) where partially completed drainage works discharge within the Site a temporary conduit shall be provided to the discharge point.

(b) Excavations for structures, pits and trenches shall not be carried out on or

adjacent to slopes unless measures are taken to drain the excavation and to prevent water from the excavation entering the slope.

(c) Geotechnical Instrumentation

(i) The Contractor shall note the existence of any instrumentation, for

example, piezometers, inclinometers and surface movement monuments, and shall install a prominent marker post at each such instrument.

(ii) Instruments shall not be removed or disturbed in any way except in

accordance with sub-clauses (iii) and (iv) below. Any instrument damaged by the Contractor shall be reinstated by him immediately.

(iii) Certain instruments shall be maintained as the Works proceed around

them. Working methods shall take account of this requirement and piezometer / settlement marker / inclinometer tubes shall be shortened or lengthened as necessary. When the adjacent works have reached their final level, a protective concrete box or other surface structure shall be constructed and a prominent marker post shall be installed.

(iv) Certain instruments shall be removed as the Works proceed but not

until the Project Manager has confirmed that it is necessary for the progress of the Works in each case.


7.4.6 Earthworks Material Allowed to become Unsuitable or to Deteriorate

(a) Earthworks material which has been used, or is required for use, in the Permanent Works and which is allowed to become unsuitable such that in the opinion of the Project Manager it no longer complies with the specified requirements for that type of material shall be replaced or dealt with by methods reviewed without objection by the Project Manager.

(b) Earthworks material which is not stated in the Contract to be excavated and

which the Contractor causes or allows to deteriorate such that in the opinion of the Project Manager the Permanent Works will be affected shall be replaced or dealt with by methods reviewed without objection by the Project Manager.

(c) Material provided to replace earthworks material which has been allowed to

become unsuitable or which the Contractor causes or allows to deteriorate shall be an equivalent material reviewed without objection by the Project Manager. The replacement material shall have the same volume after compaction as the material replaced.

(d) The material which is to be replaced shall be disposed of by the Contractor.

7.4.7 Additional Excavation and Stabilisation

(a) Earthworks material which is not stated in the Contract to be excavated but which in the opinion of the Project Manager has inadequate strength, durability or stability shall be dealt with by additional excavation and filling as stated in Clause 7.4.7(b) or by stabilisation as stated in Clause 7.4.7(c).

(b) Additional excavation shall be carried out and the resulting voids shall be

dealt with as follows:

(i) general fill material, fine fill material or special fill material shall be deposited and compacted below areas of fill and below formations other than in rock;

(ii) Grade 15 concrete shall be placed and compacted below formations in

rock; and

(iii) granular fill material shall be deposited below standing water.

(c) Stabilisation shall be carried out using rock fill material (Grade 400) deposited directly into the original unstable material and compacted to form a stable foundation on which to construct the subsequent work.

(d) During the wet season where temporary bare earth slope faces are

unavoidable they shall be protected with impermeable sheeting well secured against the wind. Where slope faces steeper than 50º and higher than 5 m are to be temporarily exposed for more than two weeks temporary hard surfacing, such as chunam, shall be provided and temporary drains shall be installed.


7.4.8 Removal of Earthworks Material

Earthworks material which is required for use in the Permanent Works as fill material shall not be removed from the Site. The Contractor shall notify the Project Manager before any earthworks material is removed from the Site.

7.4.9 Disposal of Excavated Material

(a) Excavated material which cannot be selected, processed or mixed in a practical manner to make it suitable for use in the Permanent Works as fill material shall be disposed of by the Contractor unless otherwise stated in the Contract.

(b) The Contractor shall not dispose of any materials of any type obtained from within the Site without the permission of the Project Manager.

7.4.10 Disposal of Surplus Fill and Fill Containing Materials as Defined in Clause

7.2.1(b)

(a) Pursuant to Clause 7.4.10(b), excavated or imported materials (other than those dredged), surplus to the requirements of or unsuitable for use in the Works as defined in Clause 7.2.1(b) shall be disposed of by the Contractor as defined below. The Contractor shall, prior to disposal, screen the surplus materials to yield general fill materials and rock fill material.

(b) Rock fill material which cannot be incorporated in the Works shall be deposited

in the stockpiles designated by the Project Manager.

(c) Fill materials other than rock fill material and materials as defined in Clause 7.2.1(b)(i) to (vi) which cannot be incorporated in the Works shall be deposited and compacted in accordance with Clause 7.4.26 in the stockpiles designated by the Project Manager.

(d) Materials as defined in Clause 7.2.1(b)(i) to (vi) shall become the property of

the Contractor who shall dispose of such materials off-Site. 7.4.11 Use of Excavated Material

(a) Excavated material required for use in the Permanent Works which is capable of being selected, processed and mixed to make it suitable for use as fill material shall not be used for any other purposes.

(b) Such excavated materials shall be selected and/or processed by using a

suitable screening system. If necessary, the Contractor shall blend materials to obtain fill materials to meet the various requirements.

(c) Excavated material which is required for use in the Permanent Works as fill

material and which the Project Manager permits to be removed from the Site or used for other purposes shall be replaced by an equivalent material reviewed without objection by the Project Manager. The replacement material shall have the same volume after compaction as the material which is replaced.


7.4.12 Boulders in Excavations

Boulders which project through the earthworks final surface or formation shall be dealt with as excavation proceeds by methods reviewed without objection by the Project Manager. Boulders shall not be left protruding.

7.4.13 Excavation

(a) Temporary supports or other methods shall be used to maintain excavations in a stable condition and to prevent settlement of structures or utilities due to excavation or dewatering.

(b) Contractor's Equipment or other vehicles shall not be operated or parked

adjacent to excavations. Earthworks material or other materials shall not be placed adjacent to excavations unless this has been allowed for in the design of the Temporary Works for the support of the excavation.

(c) Temporary groundwater control of excavation shall be carried out in

accordance with the requirements stated in Clause 8.18.9 and Clauses 8.19.16 to 8.19.19 inclusively.

7.4.14 Excavations Adjacent to Structures and Utilities

(a) Excavations shall be carried out by hand adjacent to, and around utilities that are known, proven or suspected to exist.

(b) Excavations adjacent to existing structures shall be carried out by hand.

7.4.15 Excavations for Structures, Pits and Trenches

(a) Excavations for structures, pits and trenches shall be the minimum size necessary to construct the Permanent Works.

(b) The length of trench excavation left open at any one time shall not exceed

that permitted by the Project Manager. (c) Trenches for utilities in areas of fill shall not be excavated until the fill material

has been deposited and compacted up to the earthworks final surface or formation or up to 1 m above the top of the utility, whichever is lower.

(d) The sides of pits and trenches shall be adequately supported at all times.

Alternatively except where the Contract expressly requires otherwise they may be suitably battered.

(e) The bottom of all excavations shall be levelled carefully and stepped or

benched horizontally as shown on the Employer’s Drawings. Any pockets of soft material or loose rock in the bottoms of pits and trenches shall be removed and the resulting cavities and any large fissures filled with Grade 10 concrete. After the placing of any blinding concrete required by the Contract, no trimming of the side faces shall be carried out for 24 hours.


(f) The Contractor shall make good with fill material as defined in Clause 7.2.1 or concrete as directed by the Project Manager:

(i) Any excavation greater than the net volume required for the works as

described in the Contract.

(ii) Any additional excavation at or below the bottom of foundations to remove material which the Contractor allows to become unsuitable.

7.4.16 Rock Splitting Using a Special Technique

(a) Where shown on the Employer’s Drawings or directed by the Project Manager, non-explosive rock-splitting techniques shall be used to form the finished rock face. Such techniques include expanding chemical grout and uncharged drillholes.

(b) Parallel holes shall be drilled in the final excavation face. The spacing of the

holes shall be determined in relation to the diameter of the drillhole and shall be within the range of 400-1000 mm.

(c) Before starting splitting along the final excavation face in any given type and

condition of rock, trials shall be carried out at least 6 m away from the final face to produce results acceptable to the Project Manager, with a minimum trial length of 4 m. The following details of the procedures used shall be submitted to the Project Manager at least 24 hours before starting to drill in the final excavation face:-

(i) diameter, spacing, depth and subdrill of rock-splitting holes; and

(ii) when using expanding chemical grout, chemical composition of the

grout and mix ratio of chemical (kg): water (kg).

(d) After review without objection by the Project Manager of the trial results, the procedures used shall be the same in all respects as in the trial. Drilling a set of rock-splitting holes in the plane of the final rock-face shall not proceed until at least 50% of the face formed by the previous adjacent splitting has been exposed and the results assessed.

(e) If the rock-splitting results deteriorate because of changes in the jointing or degree of weathering of the rock mass, without a major change necessitating new trials as sub-clause (c) hereof, procedures shall be modified as necessary, with the agreement of the Project Manager, and rock splitting shall continue in lengths of not more than 6 m until fully satisfactory results are again achieved. If necessary in the opinion of the Project Manager, new proposals shall be submitted in accordance with Clause 7.4.16(c) and this Clause, before continuing.

(f) Chemical grout holes shall not be charged until the rock broken by previous

operations has been mucked out. (g) When the chemical grout has expanded fully, the rock in front of the plane of

the drillholes shall be broken out and all traces of the solidified chemical removed.

(h) After drilling the rock-splitting holes, (for uncharged drillholes) the rock in front

of the plane of the drillholes shall be broken out by a mechanical rock breaker.


7.4.17 Surface Preparation for Fill Material

Surfaces on which fill material is to be deposited shall be prepared after site clearance in accordance with the following requirements:

(a) topsoil, grass, and other organic matter shall be removed; (b) soft spots, boulders and other materials which are unsuitable or unstable shall

be removed; (c) watercourses shall be diverted in accordance with methods reviewed without

objection by the Project Manager; (d) benches shall be cut and sub-soil drainage systems installed as stated in the

Contract; (e) voids shall be dealt with as stated in the Contract or instructed by the Project

Manager; and (f) topsoil, soil, material other than rock and all material which is capable of being

scarified, shall be scarified to a depth of 200 mm and compacted to the same standard as the fill material which is to be deposited.

7.4.18 Commencement of Deposition of Fill Material

The Contractor shall notify the Project Manager before deposition of fill material starts in any area of fill.

7.4.19 Haulage of Fill Material

Haulage of fill material to an area of fill shall commence only when the specified requirements for relative compaction of the fill material have been achieved.

7.4.20 Deposition of Fill Material

(a) Fill material obtained from excavations within the Site shall be deposited in its final location as soon as practicable after it has been excavated.

(b) Fill material shall be deposited in layers of a thickness appropriate to the

compaction method to be used. (c) Layers of fill material shall be horizontal, except for any gradient required for

drainage, and the thickness of each layer shall be uniform over the area to be filled.

(d) Except in excavations for structures, pits and trenches, if the difference in

level between adjacent areas to be filled exceeds 1 m the edge of the higher area shall be benched before fill material is placed against it.

(e) The construction of the Works shall be controlled in such a manner that any

compaction of the fill material, including that resulting from the passage of Contractor's Equipment or haulage vehicles is uniform.


(f) Fill material shall not be deposited by end-tipping, by pushing loose material down slope faces or by other methods which may result in segregation or inadequate compaction of the fill material.

(g) Isolated boulders each within the range 0.015 cu m to 0.10 cu m in size may be

incorporated in embankments not of rockfill at the discretion of the Project Manager provided that the specified compaction requirements are met and no stone exceeding 0.015 cu m shall be placed less than 2 m below formation level of carriageways or hardshoulders.

(h) In reclamation, before any other material is dumped within 90 m of any seawall,

material shall first be dumped immediately behind the wall to a width of 15 m to 30 m by working outwards from the wall unless the Project Manager directs otherwise. If directed, the Contractor shall also dump material in bunds to form self-contained areas before filling the remaining area.

(i) An accurate and up-to-date record showing dates, weather conditions, approximate elevations, source of materials, compactive effort etc shall be kept by the Contractor showing when fill is placed in various locations within the Site. This record shall be available for inspection by the Project Manager. The Contractor shall also record the results of all compaction and in-situ density tests and shall identify these results with the various locations and elevations at which fill material has been placed and the location from which the fill material was obtained.

7.4.21 Overfilling

In areas of fill formed of fill material other than rock fill material, earthworks final surfaces sloping at a gradient exceeding 1 vertical to 3 horizontal shall be formed by overfilling and cutting back after compaction. Over-filling shall extend beyond the earthworks final surface by a horizontal distance of 0.5 m or two times the thickness of the compacted layer, whichever is greater.

7.4.22 Deposition of Fill Material Adjacent to Structures and Utilities

(a) Except as stated in Clause 7.4.22(d), fill material deposited within 0.5 m of a structure or utility shall be fine fill material unless otherwise stated in the Contract. In addition, the material may contain up to 5% by weight of fresh, slightly decomposed or moderately decomposed rock fragments of up to 200 mm provided that these do not cause any damage to structures, nor do they interfere with the compaction requirements.

(b) Fill material shall not be deposited adjacent to or above structures or utilities

until the construction of the structure or utility is sufficiently advanced to accept the imposed forces without disturbance or damage.

(c) Fill material shall be deposited evenly on all sides of structures and utilities

and in such a manner that the structure or utility is not disturbed or damaged. (d) Unless otherwise stated in the Contract, fill material around water, sewage

and drainage pipes which are constructed as part of the Permanent Works shall be special fill material as defined in Clause 7.2. Fill material shall be deposited in layers not exceeding 100 mm thick to a level of 300 mm above the top of the pipe. Fill material shall be deposited in such a manner that the layer on one side of the pipe is not more than 100 mm higher than the layer on the other side.


(e) Backfill material more than 300 mm above the top of the pipe should be general fill material compacted in layers not exceeding 250 mm thick.

(f) Fill material shall be brought up to original ground level or the earthworks final

level or as directed by the Project Manager. 7.4.23 Deposition of Rock Fill Material

(a) The final compacted thickness of each layer of rock fill material shall exceed 1.5 times and shall not exceed twice the nominal grade size of the rock fill material.

(b) The surface voids of each layer of rock fill material shall be filled with

fragments of rock before the next layer is deposited. The final surface of rock fill material shall also be blinded with fine fill material.

7.4.24 Deposition of Fill Material in Excavations for Structures, Pits and Trenches

If sheet piling, timbering or other temporary supports to excavations for structures, pits and trenches are not to be left in place, the sheet piling, timbering or supports shall be removed as deposition of fill material proceeds. The supports shall be removed in such a manner that the stability of the adjacent ground is maintained and the compacted fill material is not disturbed.

7.4.25 Deposition Compaction of Materials in Trenches and Pits in Carriageways and

Footways

(a) Trenches and pits cut in carriageways and footways, which are to remain open to traffic only during the term of the Contract, shall be backfilled and compacted, to the underside of the adjacent pavement construction or to a level 260 mm below the surface, whichever is the lower. The next layer of backfilling shall be sub-base to a level 60-100 mm, as directed by the Project Manager, below the surface of adjacent construction.

(b) A tack coat of bituminous emulsion shall be applied to the surface of the compacted sub-base and the edges of the existing pavement except the edges of the friction course exposed by the excavation. Tack coating shall be applied as specified in Clause 9.5.6(d).

(c) The backfilling shall be completed with 60-120 mm of bituminous roadbase,

as specified in Clause 9.3.2. 7.4.26 Compaction of Fill Material

(a) Fill material in areas of fill shall be compacted in layers to a stable condition as soon as practicable after deposition and in a manner appropriate to the location and to the material to be compacted.

(b) The Contractor shall notify the Project Manager before the next layer is

deposited on each layer of compacted fill material.


(c) Except as stated in Clauses 7.4.27(a), 7.4.29(b) and 7.4.32(b), fill material shall be compacted to obtain a relative compaction as determined by the modified Proctor test as defined in BS 1377-4;1990 and tests defined in Geospec 3 of at least:

(i) 95% throughout;

(ii) 98% within 200 mm of formations.

7.4.27 Compaction of General Fill Material with a Large Portion of Coarse Material

(a) General fill material with material of which less than 90% passes a 20 mm BS test sieve, where it is not possible to determine the moisture content and maximum dry density according to the testing methods stated in Appendices A7.1 to A7.5, shall be compacted to the requirements of Sub-Clauses (b), and (c), or (d) of this clause.

(b) Spread and level each horizontal layer of general fill material with a thickness

not less than 1.5 times of the maximum size of the general fill material and not exceeding the maximum depth of compacted layer in accordance with Table 7.2. If this criterion is not met due to the presence of over-sized coarse material in the general fill, the over-sized coarse material shall be removed or broken down to sizes acceptable to the Project Manager. Each layer shall be systematically compacted by a vibratory roller with the stipulated minimum number of passes corresponding to the minimum static load per 100 mm width of the roller.

(c) The number of passes of the roller shall only be counted when the roller has

travelled on the material to be compacted at a speed of not more than 2 km per hour with full vibration. Plant other than a vibratory roller used to carry out material spreading or to provide some preliminary compaction only to assist the use of heavier plant shall be disregarded in counting the number of passes.

(d) Variation from the method or the use of plant different from that specified in

Sub-Clause (b) of this Clause will be permitted only if the Contractor demonstrates by Site trials that equivalent compaction is achieved by the alternative method. The procedure to be adopted for these Site trials shall be agreed with and reviewed without objection by the Project Manager.

(e) Without prejudice to the General Conditions and in order that the Project

Manager may make proper provision for the supervision of compaction in the permanent work, the Contractor shall, not less than 48 hours before he proposes to carry out compaction processes, apply in writing to the Project Manager for permission to do so.

(f) When materials of widely divergent characteristics are used in embankments

and fill areas they shall be spread and compacted in separate clearly defined areas.

(g) If more than one class of material is being used in such a way that it is not

practicable to define the areas in which each class occurs, compaction plant shall be operated as if only the material which requires the greatest compactive effort is being compacted.


Table 7.2: Compaction Requirement for General Fill Material with a Large Portion of Coarse Material

Force per 100mm

width Well-graded material Uniform-graded material

(kN)

Maximum depth of

compacted layer (mm)

Minimum no. of passes

Maximum depth of

compacted layer (mm)

Minimum no. of passes

0.25-0.45 150 16 0.46-0.70 150 12 0.71-1.25 125 12 150 6 1.26-1.75 150 8 200 10 1.76-2.30 150 4 225 12 2.31-2.80 175 4 250 10 2.81-3.50 200 4 275 8 3.51-4.20 225 4 300 8 4.21-4.90 250 4 300 8

7.4.28 Moisture Content of Fill Material

Fill material other than rock fill material and material as stated in Clause 7.4.27(a) shall be at optimum moisture content during compaction. Fill material at a moisture content within ± 3% of the optimum moisture content, may be acceptable provided that it is capable of compaction, in accordance with the specified requirements, to form stable areas of fill.

7.4.29 Compaction of Fill Material Adjacent to Structures and Utilities

(a) Fill material shall be compacted in such a manner that structures or utilities are not disturbed or damaged.

(b) Fill material around water, sewage and drainage pipes which are constructed

as part of the Permanent Works shall be compacted by hand-rammers or manually operated power equipment. Fill material within 300 mm above the top of sewage and drainage pipes shall be compacted to obtain a relative compaction of at least 85% throughout.

7.4.30 Compaction of Rock Fill Material

(a) Every layer of rock fill material shall be compacted by at least eight passes of a vibrating roller or by other equivalent compaction method reviewed without objection by the Project Manager. The final surface of rock fill material shall be compacted by at least two additional passes of a vibrating roller or by other equivalent compaction method reviewed without objection by the Project Manager.

(b) Vibratory rollers used for the compaction of rock fill material shall have a static

load per 100 mm width of roll of at least 2 kN for layers with a compacted thickness not exceeding 500 mm and at least 4 kN for layers with a compacted thickness exceeding 500 mm.


7.4.31 Completion of Earthworks Final Surfaces

(a) Earthworks final surfaces shall be completed to a stable condition as soon as practicable after excavation or after deposition and compaction of fill material has been completed. The subsequent Permanent Works or surface protection shall be carried out as soon as practicable after the earthworks final surface has been completed.

(b) Earthworks final surfaces shall be completed to smooth alignments without

abrupt irregularities unless otherwise stated in the Contract. 7.4.32 Completion of Formations

(a) Formations above structures or utilities shall be completed after construction of the structure or utility.

(b) Except in excavations in rock and in areas of fill formed of rock fill material or

fill material as stated in Clause 7.4.27(a), formations shall be compacted to obtain a relative compaction of at least 98% to a depth of 200 mm below the formation.

(c) Proof rolling shall be carried out on formations unless otherwise reviewed

without objection by the Project Manager. The Project Manager shall be notified prior to commencement of proof rolling. The formation shall be rolled by at least two passes of a non-vibrating rubber tyred roller. The roller shall have a static load per 100 mm width of roll of at least 4 kN and shall travel at a speed not exceeding 2 km/h. Any defect in the formation which is revealed during proof rolling by deformation of the formation which in the opinion of the Project Manager is excessive shall be made good as directed by the Project Manager.

(d) After all other formation work and testing have been completed and damage

caused by testing reinstated, formations for pavements shall be rolled with one pass of a smooth steel-wheeled non-vibrating roller. The roller shall have a load per 100 mm width of roll of at least 2 kN.

(e) Formations which will not be immediately covered shall be protected by

methods reviewed without objection by the Project Manager. (f) Surface irregularities in formation after trimming of the rock excavation shall be

regulated to the requirements of this Section with granular fill material, no-fines concrete or lean concrete as determined by the Project Manager.

7.4.33 Protection of Earthworks Final Surfaces and Formations

(a) Earthworks final surfaces and formations shall be maintained in a stable condition and shall be protected from damage due to water or other causes and from exposure to conditions which may adversely affect the surface.

(b) Formations shall not be used by Contractor's Equipment or vehicles other

than those which are essential to construct the subsequent work.


(c) If the Contractor wishes to continue to use the surface of embankments for construction traffic before trimming to formation level he shall bring up and maintain the area between the extremities of the carriageway(s), including (if any) central reserve and hardshoulders to a level not less than 150 mm above formation level whereupon construction traffic will be allowed to use the surface so formed but any damage to the earthworks final surface caused by the use of such surface shall be made good by the Contractor.

(d) In areas of shallow filling where after removal of topsoil the ground level is

within 300 mm of the earthworks final surface level, construction traffic shall not use the surface unless the Contractor brings up and maintains the surface level at least 300 mm above the earthworks final surface level. Any damage to the subgrade arising from such use shall be made good by the Contractor with material having the same characteristics as the damaged material.

7.4.34 Tolerances: Earthworks Final Surfaces and Formations

(a) Earthworks final surfaces and formations shall be within the tolerances stated in Table 7.3 of the specified lines and levels. The tolerances for formations do not apply for pipes or preformed structures which require support over their complete length or area.

(b) In excavation, a positive tolerance refers to insufficient excavation and a

negative tolerance refers to excess excavation. In areas of fill, a positive tolerance refers to excess fill material and a negative tolerance refers to insufficient fill material.

Table 7.3: Tolerances for Earthworks Final Surfaces and Formations

Type of surface Method of forming surface Tolerance (mm)

+ -

Formations for structures and utilities

Excavation except in rock 0 25 Excavation in rock 0 150Deposition and compaction of fill material 0 25

Formations for pavements including carriageways, footways, cycletracks, paved areas, aircraft pavements and railway trackbeds.

Excavation except in rock 0 50 Excavation in rock 0 150 Deposition and compaction of fill material 0 50

Earthworks final surfaces other than formations, with a gradient not exceeding 1 vertical to 10 horizontal

Excavation except in rock 0 100Excavation in rock 0 200 Deposition and compaction of fill material 0 100

Other earthworks final surfaces

Excavation except in rock 100 100 Excavation in rock 100 200Deposition and compaction of fill material 100 100


7.4.35 General Ground Treatment: Vibrocompaction

Where treatment of the ground is to be carried out using methods of vibro-compaction and/or vibro-replacement, the Contractor shall submit to the Project Manager for his review without objection details of the method, Contractor's Equipment and materials he intends to use and, notwithstanding any other requirements of the Contract, the testing he intends to carry out to demonstrate that he has achieved the degree of ground improvement as specified. The Contractor shall demonstrate to the Project Manager's satisfaction that the persons carrying out the work are suitably experienced.

7.4.36 Existing Instrumentation

(a) The Contractor shall note the existence of any instrumentation (e.g. piezometers, inclinometers and surface movement monuments) shown on the Employer’s Drawings and shall install a prominent marker post at each such instrument.

(b) Instruments shall not be removed or disturbed in any way except in

accordance with Sub-Clauses (c) and (d) below. Any instrument damaged by the Contractor shall be reinstated by him immediately and at his own expense.

(c) Certain instruments, if so shown on the Employer’s Drawings, shall be

maintained as the Works proceed around them. Working methods shall take account of this requirement and piezometer/settlement marker/inclinometer tubes shall be shortened or lengthened as necessary. When the adjacent works have reached their final level, a protective concrete box (or other surface structure as shown on the Employer’s Drawings) shall be constructed and a prominent marker post shall be installed.

(d) Certain instruments, if so shown on the Employer’s Drawings, shall be

removed as the Works proceed but not until the Project Manager has confirmed that it is necessary for the progress of the Works in each case.

7.4.37 Excavation for Utilities Trenches in Hard Materials

The Contractor shall form trenches for the installation of utilities at locations where excavation is in hard materials. He shall programme the trench excavation so that it is completed in advance of the work by the utility undertaking. He shall backfill the trenches with fine fill material in horizontal layers and compact as directed by the Project Manager.

7.5 INSPECTION, TESTING AND COMMISSIONING 7.5.1 Batch: Fill Material

A batch of fill material is any quantity of fill material of the same type and which has similar properties throughout. For the purpose of testing for moisture content and relative compaction a batch shall, in addition to the above, be fill material which is deposited in a single layer in any area of fill presented by the Contractor for testing on one occasion.


7.5.2 Samples: Fill Material

(a) Each sample of fill material shall consist of at least four increments taken from different parts of the batch. The increments shall be combined and thoroughly mixed and shall then be divided by quartering or by using a riffle box to obtain specimens of an appropriate size to carry out the individual tests.

(b) The size of samples of fill material other than rock fill material shall be in

accordance with Section 2.5 in Geospec 3. Each sample of rock fill material of grade size not exceeding 200 shall have a mass of at least 250 kg and each sample of rock fill material of grade size exceeding 200 shall have a mass of at least 1000 kg.

7.5.3 Test – Fill Material General

All tests as required by the Project Manager shall be carried out by a HOKLAS accredited laboratory reviewed without objection by the Project Manager.

7.5.4 Samples: Particle Size Distribution, Liquid Limit, Plasticity Index, Coefficient

of Uniformity, Sulphate Content

Samples of fill material to be tested for particle size distribution, liquid limit, plasticity index, coefficient of uniformity and sulphate content shall be delivered at least 14 days, before deposition of the fill material starts. The number of samples to be provided from each batch shall be as stated in Table 7.4.

Table 7.4: Number of Samples to be Tested for Particle Size Distribution, Liquid Limit, Plasticity Index, Coefficient of Uniformity, Sulphate Content, Optimum Moisture Content and Maximum Dry Density

Description Size of batch No. of samples per batch

Special fill material 0 - 3,000 m³ 3

exceeding 3,000 m³ 1 for each 1,000 m³ or part thereof

Fill material other than special fill material

0 - 15,000 m³ 3

exceeding 15,000 m³ 1 for each 5,000 m³ or part thereof 7.5.5 Testing: Particle Size Distribution, Liquid Limit, Plasticity Index, Coefficient of

Uniformity, Sulphate Content

(a) Each sample of fill material taken as stated in Clause 7.5.4 shall be tested to determine the particle size distribution. In the case of special fill material testing shall include calculation of the coefficient of uniformity as stated in Clause 7.5.5(d). Each sample of fill material other than rock fill material shall be tested to determine the liquid limit and the plasticity index of that portion of the fill material passing a 425m BS test sieve. Each sample of fill material which will be deposited within 500 mm of concrete, cement bound material, cementitious material or metalwork shall be tested to determine the soluble sulphate content.


(b) The method of testing shall be in accordance with the following tests as stipulated in Geospec 3:

Particle size distribution : Clause 7.5.5(c) Liquid limit : test method 6.1 Plasticity index : test method 6.1 Soluble sulphate : test method 9.3 Total sulphate : test method 9.3

(c) The particle size distribution of fill material passing a 75mm BS test sieve shall be determined in accordance with a test specified in Section 3 in Geospec 3, whichever as instructed by the Project Manager. The size of particles of fill material which do not pass a 75 mm BS test sieve shall be taken as the largest dimension measured in any plane.

(d) The coefficient of uniformity (Cu) shall be calculated from the equation:

Cu = D60/D10

Where:

- D60 and D10 are the equivalent sieve sizes in millimetres, interpolated

from the particle size distribution curve, through which 60% and 10% of the fill material would pass respectively.

7.5.6 Non-compliance: Particle Size Distribution, Liquid Limit, Plasticity Index,

Coefficient of Uniformity, Sulphate Content

(a) If the result of any test for soluble sulphate content of fill material does not comply with the specified requirements for soluble sulphate content, each sample shall be tested to determine the total sulphate content.

(b) If the result of any test for particle size distribution, liquid limit, plasticity index,

coefficient of uniformity or total sulphate content of fill material does not comply with the specified requirements for the property, additional samples shall be provided from the same batch and additional tests for the property shall be carried out. The number of additional samples shall be as stated in Table 7.4.

7.5.7 Samples: Optimum Moisture Content, Maximum Dry Density

(a) Samples of fill material to be tested for optimum moisture content and maximum dry density shall be delivered at least 72 hours before deposition of the fill material starts. The number of samples to be provided from each batch shall be stated in Table 7.4

(b) The Contractor shall notify the Project Manager of the exact location in which

the fill material from which each sample is taken is to be deposited.


(c) Samples to be tested for optimum moisture content and maximum dry density shall also be taken after the fill material has been deposited in its final position, at intervals of not more than 28 days.

(d) Samples shall not be provided from fill material including rock fill material

which contains an insufficient proportion of particles passing a 20 mm BS test sieve to permit determination of the moisture content and maximum dry density.

7.5.8 Testing: Optimum Moisture Content, Maximum Dry Density

(a) Each sample of fill material taken as stated in Clause 7.5.7 shall be tested to determine the optimum moisture content and the maximum dry density.

(b) The method of testing shall be in accordance with the following:

Optimum moisture content: Geospec 3 – test method 10 Maximum dry density : Geospec 3 – test method 10 adjusted in

accordance with Appendix A7.5 where appropriate.

(c) If permitted by the Project Manager, the Hilf method stated in Appendix A7.4

may be used instead of the methods stipulated in Clause 7.5.8(b) to determine the optimum moisture content and maximum dry density.

(d) If in the opinion of the Project Manager there is any undue discrepancy

between the results of tests for optimum moisture content of fill material using methods stipulated in Clause 7.5.8(b) and the results of tests using the Hilf method, the results of tests using methods stipulated in Clause 7.5.8(b) shall prevail.

7.5.9 Consistency: Optimum Moisture Content, Maximum Dry Density

If the result of any test for optimum moisture content or maximum dry density of fill material indicates that the batch contains material which differs to such an extent that subsequent tests for relative compaction may be affected, the batch shall be divided into smaller batches; each of the smaller batches shall comprise material with similar properties throughout. Additional samples shall be provided from each of the smaller batches and additional tests for optimum moisture content and maximum dry density shall be carried out. The number of additional samples shall be as stated in Table 7.4.

7.5.10 Samples: Moisture Content

(a) Samples of fill material to be tested for moisture content shall be taken during deposition and compaction of fill material and shall be delivered to the laboratory not more than 1 hour after the fill material has been deposited in its final position.

(b) The number of samples to be provided from each batch shall be as stated in

Table 7.5. Samples shall not be provided if, in accordance with Clause 7.5.7 d(i) or (ii), the optimum moisture content has not been determined.


7.5.11 Testing: Moisture Content (a) Each sample of fill material taken as stated in Clause 7.5.10 shall be tested to

determine the moisture content. (b) The method of testing shall be in accordance with one of the following

methods:

(i) Method 1: Geospec 3 – Test Methods 5.1, 5.2 or 5.3, whichever as instructed by the Project Manager; or

(ii) Method 2: Microwave oven drying method as stated in Appendix A7.2.

Method 1 shall be used unless otherwise permitted by the Project Manager.

7.5.12 Compliance Criteria: Moisture Content

If in the opinion of the Project Manager there is any undue discrepancy between the results of tests for moisture content of fill material using Method 1 and the results of tests using Method 2 in Clause 7.5.11, the results of tests using Method 1 shall prevail.

7.5.13 Non-compliance: Moisture Content

If the result of any test for moisture content of fill material differs from the optimum moisture content by more than the specified amount, the moisture content of the whole of the batch of fill material shall be adjusted. Additional samples shall be provided from the same batch and additional tests for moisture content shall be carried out. The number of additional samples shall be as stated in Table 7.5.

Table 7.5: Number of Samples to be Tested for Moisture Content and Number

of Tests for Relative Compaction

Description Size of area of fill in batch

No. of samples/No. of tests per batch

Areas of fill in excavations for Structures, pits and trenches and on Formations

0 - 100 m² 3 100 - 500 m² 2 for each 100 m² or part thereof

exceeding 500 m² 1 for each 100 m² or part thereof

Other areas of fill

0 - 1 ha 4 for each 1000 m² or part thereof 2 - 10 ha 3 for each 1000 m² or part thereof

exceeding 10 ha 2 for each 1000 m² or part thereof 7.4.14 Testing: Relative Compaction

(a) Each batch of fill material shall be tested to determine the relative compaction. Tests shall be carried out after the fill material has been deposited and compacted in its final position. The number of tests on each batch shall be as stated in Table 7.5. Tests shall not be carried out on fill material including rock fill material which contains an insufficient proportion of particles passing a 20 mm BS test sieve to permit determination of the relative compaction.


(b) Tests shall be carried out at positions which in the opinion of the Project Manager are representative of the batch of compacted fill material as a whole.

(c) Testing shall be carried out by the Contractor. (d) The relative compaction of fill material shall be determined in accordance with

one of the following methods:

(i) Method 1: The relative compaction (RC) shall be calculated from the equation:

RC = IDD/MDD x 100%

where:

- IDD is the in-situ dry density, determined as stated in Clause

7.5.14(e) - MDD is the maximum dry density, determined as stated in Clause

7.5.8(b)

Method 2: The relative compaction (RC) shall be calculated from the equation:

RC = IBD/MCBD x 100% where:

- IBD is the in-situ bulk density determined as stated in Clause

7.5.14(e) - MCBD is the maximum converted bulk density determined by the

Hilf method as stated in Appendix A7.4


(e) The in-situ bulk density and the in-situ dry density of fill material shall be determined in accordance with one of the following methods:

(i) Method 1: GEO Report No. 36, Test 9.2.1or 9.2.2 as appropriate to

the grain size of the fill material; or (ii) Method 2: Nuclear densometer method as stated in Appendix A7.3.


(f) The maximum converted bulk density of fill material of which more than 5% is

retained on a BS 20 mm test sieve shall be adjusted as stated in Appendix A7.5.

7.5.15 Compliance Criteria: Relative Compaction

If in the opinion of the Project Manager there is any undue discrepancy between the results of tests for relative compaction of fill material using Method 1 and the results of tests using Method 2 in Clause 7.5.14, the results of tests using Method 1 shall prevail.


7.5.16 Non-compliance: Relative Compaction

If the result of any test for relative compaction of fill material does not comply with the specified requirements for relative compaction, additional tests for relative compaction shall be carried out on the same batch. The number of additional tests shall be as stated in Table 7.5.


APPENDIX A7.1

TEST METHODS FOR FILL MATERIAL A7.1.1 General

The definitions, terms, abbreviations, symbols, and grouping of materials stated in BS 1377: 1975 shall apply except as stated in Clauses A7.1.2 and A7.1.3.

A7.1.2 Terms and Symbols

Terms used in the Specification, and in BS 1377: 1975 are identified by the abbreviations and symbols stated in Table A7.1.1.

Table A7.1.1: Abbreviations and Symobls

Abbreviation/Symbol Term BD bulk density

CBD Converted bulk density DD dry density IBD In-situ bulk density IDD in-situ dry density

MDD Maximum dry density MCBD Maximum converted bulk density

RC Relative compaction w moisture content wi in-situ moisture content

wo Optimum moisture content A7.1.3 Grouping of Material

(1) Fine grained material is material of which at least 90% passes a 2 mm BS test sieve.

(2) Medium grained material is material of which at least 90% passes a 20 mm

BS test sieve and more than 10% is retained on a 2 mm BS test sieve.


APPENDIX A7.2

DETERMINATION OF THE MOISTURE CONTENT OF FINE GRAINED AND MEDIUM GRAINED MATERIAL

BY THE MICROWAVE OVEN DRYING METHOD A7.2.1 Scope This method covers the determination of the moisture content of fine grained and

medium grained material as a percentage of the mass of the dry material. A7.2.2 Apparatus The following apparatus is required:

(1) A microwave oven with a timer and an adjustable power setting.

(2) An airtight container of microwave safe and non-reflective material.

(3) A balance readable and accurate to 0.01 g.

(4) A desiccator containing anhydrous silica gel. A7.2.3 Procedure

(1) The container shall be cleaned, dried and weighed to the nearest 0.01 g (m1).

(2) A specimen shall be crumbled and placed loosely in the container and the lid shall be replaced. Each specimen of fine grained material shall be at least 30 g and each specimen of medium grained material shall be at least 300 g. Specimens of medium grained material may be tested in several parts each less than 300 g and the results aggregated.

(3) The container and contents shall be weighed to the nearest 0.01 g (m2).

(4) The lid of the specimen container shall be removed and the container with its

lid and contents shall be placed in the microwave oven and dried. The specimen shall be considered to be dry when, after an initial drying period, successive weighings at intervals of 1 minute produce results which are the same to the nearest 0.01 g. Alternatively, the oven may be set to an appropriate time and power setting to dry the specimen as determined by calibration of the oven on soil of a similar type.

(5) After drying, the container and contents shall be removed from the microwave

oven and placed in the desiccator to cool.

(6) The lid shall be replaced and the container and contents shall be weighed to the nearest 0.01 g (m3).


A7.2.4 Calculation

The moisture content of the material (w) shall be calculated as a percentage of the dry mass of the material from the equation:

w = (m2 - m3)/(m3 - m1) x 100% where: - m1 is the mass of the container (g) - m2 is the mass of the container and contents before drying (g) - m3 is the mass of the container and contents after drying (g)


The following shall be reported:

(1) source and identification of the soil;

(2) the moisture content of the material to the nearest 0.1%; and

(3) that the test method used was in accordance with this General Materials and



APPENDIX A7.3

DETERMINATION OF THE IN-SITU BULK DENSITY AND THE IN-SITU DRY DENSITY OF FINE GRAINED

AND MEDIUM GRAINED MATERIAL BY THE NUCLEAR DENSOMETER METHOD

A7.3.1 Scope

This method covers the determination of the in-situ bulk density of fine grained and

medium grained material by the attenuation of gamma rays and calculation of the in-situ dry density using a moisture content determined in accordance with either GEO Report No. 36, Test 2.3.2A or 2.3.2B or Appendix A7.2, whichever as instructed by the Project Manager.

A7.3.2 Apparatus

The following apparatus is required:

(1) A nuclear device for the measurement of density (densometer). The details of construction of the densometer may vary but the following general requirements shall apply:

- The probe shall be an adjustable probe containing a gamma source which

can be readily positioned in a preformed hole. The probe assembly shall be graduated in increments not exceeding 50 mm and shall be constructed in such a manner that it will be securely held in the test depth position.

- The instrumentation shall display the results directly in metric units.

(2) A reference standard of uniform and constant density to establish the

background count and count reproducibility.

(3) Site preparation equipment, such as spades, straight-edges, scoops and brushes, required to prepare a suitably cleared and level surface to accommodate the densometer.

(4) A hole forming device, such as an auger or steel pin, to form a hole to

accommodate the probe. The device shall have a nominal diameter which exceeds the probe diameter by not more than 3 mm and shall be graduated to indicate the depth of the hole. The device shall have a guide which will ensure that the hole is formed normal to the prepared surface.

(5) Sampling equipment, such as augers, spades, picks, small digging tools,

scoops, airtight containers and bags, to obtain samples of the material.

(6) Apparatus for the determination of the moisture content in accordance with either GEO Report No. 36, Test 2.3.2A or 2.3.2B or Appendix A7.2, whichever as instructed by the Project Manager.


A7.3.3 Procedure: Comparability of Test Methods

(1) Before using the densometer on material for which it has not previously been used, the results of determinations of in-situ bulk density using the densometer shall be compared with the results of determinations of in-situ bulk density in accordance with GEO Report No. 36, Test 9.2.2. The location of each determination in accordance with GEO Report No. 36, Test 9.2.2 shall correspond to the midpoint of the densometer probe and the gamma sensor. A minimum of ten pairs of determinations shall be carried out.

(2) If the difference between any pair of results does not exceed 0.08 Mg/m³ and

if the densometer produces results which are both higher and lower than those produced in accordance with GEO Report No. 36, Test 9.2.2, the densometer may be used without correction.

(3) If either of the criteria stated in Clause A7.3.3(2) is not met, the densometer

shall not be used.

A7.3.4 Procedure: Routine Denosometer Check

The procedure for carrying out a routine densometer check shall be as follows: (1) The densometer shall be warmed up in accordance with the manufacturer's

recommendations.

(2) A standard count shall be carried out in accordance with the manufacturer's recommendations. The standard count shall be carried out by placing the reference standard on a hard, level surface consisting of material with a density of at least 1.6 Mg/m³. The reference standard shall be placed at a distance of at least 10 m from any other nuclear device and at least 3 m from any large object. At least three count readings shall be taken and the mean of the three readings shall be determined. The mean shall be the standard count reading for the day.

(3) The standard count reading for the day shall be compared with the mean of

the standard count readings for the previous 4 days. If the difference is greater than that recommended by the manufacturer or if no recommendation is made and the difference is greater than 1%, the densometer shall not be used.

(4) The densometer shall be left switched on with the probe in the locked

position. If the densometer is switched off a further standard count shall be carried out in accordance with Clause A7.3.4(2) and (3).

A7.3.5 Procedure: Determination of In-Situ Bulk Density

The procedure for determination of the in-situ bulk density shall be as follows:

(1) A level surface of sufficient size to accommodate the densometer shall be

prepared and cleared of all disturbed and loose material. The depth of any depression below the densometer shall not exceed 3 mm. Depressions exceeding 3 mm in depth shall be filled using fine sand or material taken from the adjacent soil which passes a 600 μm BS test sieve.


(2) A suitable hole for the probe shall be prepared using the hole forming device. The hole shall be normal to the prepared test area and at least 50 mm deeper than the intended test depth. If a driven pin is used to form the hole, the pin shall be rotated every two or three blows to facilitate its removal.

(3) The test depth shall be the same as the maximum depth required for determination of the in-situ bulk density in accordance with GEO Report No. 36, Test 9.2.1 or 9.2.2 as appropriate to the grain size of the material.

(4) The probe shall be positioned and inserted into the hole in such a manner that

the gamma source is shielded at all times. The probe shall be seated firmly against the side of the hole nearest to the back of the densometer by gently pulling the densometer backwards until contact is achieved. The operator shall ensure that the densometer is correctly seated and the depth setting on the control panel is the same as the probe depth.

(5) The operator shall ensure that there are no other radioactive sources within

10 m of the densometer.

(6) Three readings of the in-situ bulk density shall be taken in accordance with the manufacturer's recommendations and the mean determined. If any one reading differs from any other reading by more than 0.015 Mg/m³, additional readings shall be taken until three consecutive readings which do not differ by more than 0.015 Mg/m³ are obtained and the mean determined. The mean of the three readings shall be taken as the in-situ bulk density (IBD). If the above criterion is not met after six readings, the densometer shall not be used.

(7) The densometer shall be removed and a minimum 500 g sample of the

material directly beneath the densometer position shall be taken for determination of the moisture content. The sample shall be obtained by augering or digging to the test depth. The sample shall be placed in a moisture tight container and the lid replaced. The moisture content (w) shall be determined in accordance with either GEO Report No. 36, Test 2.3.2A or 2.3.2B or Appendix A7.2, whichever as instructed by the Project Manager.

(8) If a sample of material at the same location as the densometer test is required

for determination of the maximum dry density or the maximum converted bulk density, the sample shall be obtained by digging to the test depth, keeping the sides of the excavation vertical and the bottom flat and level. The appropriate quantity of material required for the test shall be taken, placed in a moisture tight container and the container sealed.

A7.3.6 Calculation

The in-situ dry density of the material (IDD) shall be calculated from the equation:

IDD = IBD/(1 + w ) Mg/m³ 100 where: - IBD is the in-situ bulk density of the material (Mg/m³) - w is the moisture content of the material (%)


A7.3.7 Reporting of Results The following shall be reported:

(1) the location of the test; (2) the in-situ dry density to the nearest 0.01 Mg/m³; (3) the moisture content to the nearest 0.1%; and (4) that the test method used was in accordance with this General Materials and



APPENDIX A7.4

DETERMINATION OF THE MAXIMUM CONVERTED BULK DENSITY BY THE HILF METHOD

A7.4.1 Scope This method covers the determination of the maximum converted bulk density and

the difference between the optimum moisture content and the in-situ moisture content of a material by relating the converted bulk density and the moisture added.

A7.4.2 Apparatus The following apparatus is required:

(1) Apparatus in accordance with GEO Report No. 36, Test 4.3.3A or 4.3.3B,

whichever as instructed by the Project Manager.

(2) Apparatus for determination of the moisture content in accordance with either GEO Report No. 36, Test 2.3.2A or 2.3.2B or Appendix A7.2, whichever as instructed by the Project Manager.

(3) Apparatus to extract specimens from the mould.

(4) Apparatus, such as a warm air blower, for rapid drying of the material.

A7.4.3 Procedure


(1) A sample of material shall be taken immediately after completing the in-situ bulk density test at the same location as the test. The sample shall be obtained by digging to the same depth as that of the in-situ bulk density test, keeping the sides of the excavation vertical and the bottom flat and level. The size of the sample shall be sufficient to yield a minimum of 10 kg after screening over a 20 mm BS test sieve.

(2) The sample shall be weighed to the nearest 0.01 g.

(3) The sample shall be screened over a 20 mm BS test sieve, ensuring that

moisture loss is kept to a minimum and that any free moisture appearing in the containers is worked back into the sample.

(4) The amount retained on the sieve shall be weighed to the nearest 0.01g and

expressed as a percentage of the mass of the sample. If the percentage exceeds 5%, an adjustment for coarse material shall be made in accordance with Appendix A7.5. If the percentage does not exceed 5%, no adjustment is required.

(5) The material to be tested shall be thoroughly mixed and divided by quartering

or by using a riffle box to obtain a minimum of four specimens of at least 2500g each, ensuring that moisture loss is kept to a minimum. Alternatively, if it has previously been ascertained that the material is not susceptible to crushing, a single specimen of at least 2500 g may be used for repeat testing.


(6) Each specimen shall be weighed to the nearest 0.01g and the result shall be

taken as the mass of the specimen at the in-situ moisture content.

(7) Each specimen and any remaining material shall be placed in separate moisture-tight containers and the containers sealed.

(8) The converted bulk density of at least three specimens shall be plotted

against the amount of water added or removed as a percentage of the mass of the specimen at the in-situ moisture content (z) on a graph as shown in the Hong Kong Government Civil Engineering Department Standard Drawing No. C2006, in accordance with the procedure stated in Clause A7.4.3(9) to (15).

(9) The first point on the graph shall be obtained as follows:

- A specimen shall be compacted at its in-situ moisture content in

accordance with GEO Report No. 36, Test 4.3.3A, Clause 4.3.3A.4 or Test 4.3.3B, Clause 4.3.3B.4, whichever as instructed by the Project Manager.

- A diametrical slice of approximately 400 g to 500 g shall be cut from the

specimen along its entire length. The in-situ moisture content of the slice (wi) shall be determined in accordance with either GEO Report No. 36, Test 2.3.2A or 2.3.2B or Appendix 7.2, whichever as instructed by the Project Manager.

- The bulk density (BD1) shall be calculated as stated in Clause A7.4.4(1)

and plotted on the 0% ordinate of the graph as the converted bulk density (CBD1).

(10) The second point on the graph shall be obtained as follows:

- A second specimen shall be examined and, if the in-situ moisture

content obviously exceeds the optimum moisture content, the procedure stated in Clause A7.4.3(11) shall be followed.

- The moisture content of the specimen shall be increased by adding an

amount of water equal to 2% of the mass of the specimen. The specimen shall be thoroughly mixed and compacted in accordance with the method stipulated in Clause A7.4.3(9).

- The bulk density (BD2) shall be calculated as stated in Clause

A7.4.4(1), adjusted to converted bulk density (CBD2) as stated in Clause A7.4.4(2) and plotted on the +2% ordinate of the graph.

(11) If the in-situ moisture content of the second specimen obviously exceeds the

optimum moisture content, the specimen shall be dried until the amount of water removed is approximately 2% of the mass of the specimen and cooled. The specimen shall be thoroughly mixed and compacted in accordance with the method stipulated in Clause 7.4.3(9). The amount of water removed shall be determined. The bulk density (BD2) shall be calculated as stated in Clause A7.4.4(1), adjusted to converted bulk density (CBD2) as stated in Clause A7.4.4(2) and plotted on the negative ordinate of the graph at a point which corresponds to the amount of water removed.


(12) The third point on the graph shall be obtained as follows: - If the plotted value of CBD2 is equal to or greater than the plotted-value

of CBD1, the moisture content of a third specimen shall be increased by adding an amount of water equal to 4% of the mass of the specimens. Alternatively, if the procedure stated in Clause A7.4.3(11) has been followed, the specimen shall be dried until the amount of water removed is approximately 4% of the mass of the specimen after cooling.

- If the plotted value of CBD2 is less than the plotted value of CBD1, the

third specimen shall be dried until the amount of water removed is approximately 2% of the mass of the specimen after cooling. Alternatively, if the procedure stated in Clause A7.4.3(11) has been followed, the moisture content shall be increased by adding an amount of water equal to 2% of the mass of the specimen.

- The specimen shall be thoroughly mixed and compacted in accordance

with the method stipulated in Clause A7.4.3(9). The amount of water removed shall be determined.

- The bulk density (BD3) shall be calculated as stated in Clause

A7.4.4(1), adjusted to converted bulk density (CBD3) as stated in Clause A7.4.4(2) and plotted on the graph at a point which corresponds to the amount of water added or removed.

(13) If the centre point of the three points plotted is lower than one of the other two

points, or is higher than one point and equal to the other, an additional point or points shall be obtained by proceeding in 2% increments or decrements as appropriate.

(14) If it is apparent that the moisture condition of the material is such that a total

of five points will not result in the determination of the optimum moisture content, increments and decrements of 3% moisture content may be adopted for the entire procedure.

(15) A smooth approximately parabolic curve shall be drawn to the plotted points.

The peak value of the curve shall be determined as the maximum converted bulk density (MCBD).

(16) The amount of water added or removed as a percentage of the mass of the

specimen at the in-situ moisture content corresponding to the maximum converted bulk density shall be determined (zm).

(17) The value of the moisture correction curve passing through the peak value of

the plotted parabolic curve shall be determined (zc). If there is no moisture correction curve passing through the peak value of the curve, a moisture correction curve shall be drawn through the peak by interpolating to the nearest 0.1%.


A7.4.4 Calculation

(1) The bulk density (BD) shall be calculated from the equation:

BD = (m2 - m1)/V Mg/m³

where: - m1 is the mass of the mould and base (g) - m2 is the mass of the mould, base and wet material (g) - V is the volume of the mould (mL)

(2) The converted bulk density (CBD) shall be calculated from the equation:

CBD = BD/(1+z/100) Mg/m³

where: - z is the amount of water added or removed as a percentage of the mass

of the specimen at the in-situ moisture content - z is negative for values below the in-situ moisture content

(3) The difference between the optimum moisture content (wo) and the in-situ moisture content (wi) of the material shall be calculated from the equation:

wo - wi = zm + zc % where: - zm is the amount of water added or removed as a percentage of the

mass of the specimen at the in-situ moisture content corresponding to the maximum converted bulk density (%)

- zc is the value of the moisture correction curve passing through the

peak value of the plotted parabolic curve (%)

(4) The optimum moisture content (wo) shall be calculated from the equation:

wo = wi + (1 + wi/100) zm % where: - wi is the in-situ moisture content of the material (%)

(5) The maximum dry density (MDD) shall be calculated from the equation:

MDD = MCBD/(1 + wi/100) Mg/m³ where: - MCBD is the maximum converted bulk density of the material (Mg/m³)


(6) The relative compaction (RC), if required, shall be calculated from the equation:

RC = IBD/MCBD x 100% where: - IBD is the in-situ bulk density of the material determined in accordance

with GEO Report No. 36, Test 9.2.1 or 9.2.2 as appropriate to the grain size of the material or in accordance with Appendix A7.3


The following shall be reported;

(1) source and identification of the soil; (2) the graph showing the plotted points and the parabolic curve passing through

them; (3) the maximum converted bulk density to the nearest 0.01 Mg/m³; (4) the optimum moisture content to the nearest 0.1%; (5) the maximum dry density to the nearest 0.01 Mg/m³; (6) the relative compaction to the nearest 0.1%, if determined; (7) the percentage retained on the 20 mm BS test sieve and the percentage

retained on the 37.5 mm BS test sieve to the nearest 1%, if applicable; (8) whether the test was carried out using individual specimens or repeat testing

of a single specimen; (9) whether a manual or an automatic compaction rammer was used; and (10) that the test method used was in accordance with this General Materials and



APPENDIX A7.5

ADJUSTMENT OF THE MAXIMUM CONVERTED BULK DENSITY FOR THE DETERMINATION OF THE RELATIVE COMPACTION

A7.5.1 Scope

This method covers the adjustment of the maximum converted bulk density determined in accordance with Appendix A7.4 for the determination of the relative compaction of a material containing more than 5% of the mass of the material at the in-situ moisture content retained on a 20 mm BS test sieve.

A7.5.2 Apparatus


(1) Apparatus in accordance with Appendix A7.4.

(2) A 20 mm and a 37.5 mm BS test sieve.

(3) A mould with collar as used for determination of the California Bearing Ratio (CBR mould).

(4) An extrusion device as used for determination of the California Bearing Ratio.

A7.5.3 Procedure


(1) If the amount of material retained on the 20 mm BS test sieve exceeds 5% and does not exceed 20%, the material passing the sieve shall be compacted in accordance with Appendix A7.4. The maximum converted bulk density (MCBD20) shall be determined and adjusted as stated in Clause A7.5.4.

(2) If the amount of material retained on the 20 mm BS test sieve exceeds 20%,

the retained material shall be screened over the 37.5 mm BS test sieve. The procedure stated in either Clause A7.5.3(3) or Clause A7.5.3(4) as appropriate shall be followed.

(3) If the amount of material retained on the 37.5 mm BS test sieve does not

exceed 5%, the procedure stated in Clause A7.5.3(5) shall be followed.

(4) If the amount of material retained on the 37.5 mm BS test sieve exceeds 5% and does not exceed 20%, the retained material shall be replaced with an equal mass of material which is of a similar nature and which is retained on a 20 mm BS test sieve but passes a 37.5 mm BS test sieve. The procedure stated in Clause A7.5.3(5) shall be followed.

(5) The procedure stated in Appendix A7.4 shall be followed except that the

material shall be compacted into the CBR mould and each layer shall be subjected to 62 blows of the rammer.


A7.5.4 Calculation

The maximum converted bulk density (MCBD) shall be calculated from the equation:

MCBD = MCBD20 [1 + m (1 - MCBD20)] Mg/m³

1 + z Gs 100

where: - MCBD20 is the maximum converted bulk density of the material passing the

20 mm BS test sieve (Mg/m³) - z is the amount of water added as a percentage of the mass of the specimen

at the in-situ moisture content corresponding to the maximum converted bulk density (%)



(1) the source and identification of the soil;

(2) the results in accordance with Appendix A7.4;

(3) the mass of the original material not passing the 20 mm and 37.5 mm BS test sieve as a percentage of the mass of the material at the in-situ moisture content to the nearest 0.1%;

(4) the type of mould used;

(5) the number of blows per layer;

(6) whether the specific gravity was measured or assumed and, if measured, the

method used; and

(7) that the test method used was in accordance with this General Materials and Workmanship Specification, and the results have been adjusted in accordance with this Appendix.

General Materials & Workmanship Specification 1/75 January 2011 Issue No. 5, Volume 1 – Civil & Structural Works Section 8 – Geotechnical Works

SECTION 8 GEOTECHNICAL WORKS 8.1 GENERAL REQUIREMENTS

The Permanent Works and materials specified below shall comply with the Sections stated, unless otherwise stated in this Section:

(a) Site clearance shall comply with Section 3.

(b) Drainage works shall comply with Section 6.

(c) Earthworks shall comply with Section 7.

(d) Concrete shall comply with Section 20.

8.2 TRIALS FOR GEOTECHNICAL WORKS

(a) Details of trials to be carried out for geotechnical works shall be as stated in the Contract.

(b) The trials shall be carried out to demonstrate that the proposed materials and

methods of construction will produce work which complies with the specified requirements.

(c) Trials shall be carried out in sufficient time before commencement of the

relevant Permanent Works starts to allow the Project Manager a sufficient period to determine if the trial complies with the specified requirements.

(d) The Contractor shall notify the Project Manager before the trial starts.

(e) Trials shall be carried out using the materials and methods of construction

submitted to the Project Manager for review. Trials shall be carried out at locations reviewed without objection by the Project Manager.

(f) If work which complies with the specified requirements has not been produced

in the trial, particulars of proposed changes to the material or methods of construction shall be submitted to the Project Manager for review; further trials shall be carried out until work which complies with the specified requirements has been produced in the trial.

(g) Geotechnical works for which trials are required shall not commence until

work which complies with the specified requirements has been produced in the trial.

(h) The material and methods of construction used to produce work which

complies with the specified requirements in a trial shall not be changed.


8.3 DEFINITIONS AND ABBREVIATIONS - GROUND INVESTIGATION 8.3.1 Block sample

Block sample is an undisturbed sample recovered by in-situ hand trimming of a block of material from the surrounding soil.

8.3.2 Bulk sample

Bulk sample is a sample of at least 10 kg mass which is representative of the grading of the material at the point of sampling.

8.3.3 Inspection pit

Inspection pit is a pit for locating and identifying underground utilities and structures. 8.3.4 Jar sample

Jar sample is a disturbed sample of at least 0.7 kg mass contained in a transparent airtight jar which has a screw cap with an airtight sealing ring.

8.3.5 Mazier sample

Mazier sample is an undisturbed sample recovered by rotary drilling using a Mazier triple tube core barrel which has inner tubes protruding proud of the outer tube to protect the material being sampled from disturbance.

8.3.6 Sample

Sample is any quantity of material obtained from the ground for the purposes of inspection, logging or testing.

8.3.7 Slope surface stripping

Slope surface stripping is the removal of surface protection and vegetation from existing slopes to expose underlying soil or rock for inspection.

8.3.8 Trial pit

Trial pit is a pit for inspecting and logging the ground and in which to carry out in-situ testing and sampling.

8.3.9 U 100 and U 76 samples U 100 and U 76 samples are undisturbed samples recovered by advancing a

thin-walled tube with a cutting edge into the soil. 8.3.10 Undisturbed soil sample Undisturbed soil sample is a sample complying with Class 1 or Class 2 of BS 5930.


8.4 SUBMISSIONS – GROUND INVESTIGATION 8.4.1 Particulars of ground investigation

The following particulars of proposed materials and methods for ground investigation shall be submitted to the Project Manager for review:

(a) details of drilling and in-situ testing equipment; (b) details of sampling equipment; and (c) details of filter materials and fill materials for drilling and testing,

8.5 WORKMANSHIP - GROUND INVESTIGATION 8.5.1 Inspection pits Inspection pits shall be formed by manual methods. 8.5.2 Trial pits

(a) The plan dimensions at the bottom of a trial pit shall be at least 1.2 m x 1.2 m and the sides of trial pits shall be vertical.

(b) The sides of trial pits shall be trimmed by manual methods to remove all

disturbed material. Supports to the sides of trial pits shall be such that the cut surface is clearly visible throughout the height of each face.

(c) The Project Manager shall be notified before fill material is deposited in trial

pits.

8.5.3 Slope surface stripping (a) Slope surface stripping shall start at the top of the slope and shall proceed

downwards. All loose material remaining on the slope after stripping shall be removed.

(b) Access shall be provided for inspection by the Project Manager. (c) Stripped areas shall be covered up at the end of each working day and during

rainstorms to prevent the ingress of water into the slope. (d) Stripped areas shall be reinstated in form, colour and conditions similar to the

original. The Project Manager shall be notified before reinstatement starts. 8.5.4 Records of inspection pits Records of inspection pits shall be kept by the Contractor on Site and a report shall

be submitted to the Project Manager for review within 3 days after each inspection pit has been excavated. The report shall contain details of the positions, depths and dimensions of all utilities and structures encountered in each inspection pit.


8.5.5 Records of trial pits and slope surface stripping

(a) Each trial pit shall be photographed as soon as excavation is complete. The full face of each of the sides and the bottom of the trial pit shall be photographed individually. One copy of specimen prints of 127 mm x 76 mm size shall be submitted to the Project Manager for review before fill material is deposited in the trial pit. The photographs shall contain the following information:

(i) number of trial pit and site reference;

(ii) measuring scale bar; and

(iii) a suitable colour comparison chart placed alongside the trial pit face.

(b) Records of trial pits shall be kept by the Contractor on Site and a report shall

be submitted to the Project Manager for review within 24 hours after each trial pit has been excavated. The report shall contain the following:

(i) details shown, and in the format shown in Figure 7 of `Geoguide 2 :

Guide to Site Investigation', Hong Kong Government 1987;

(ii) details of depths and rate of groundwater seepage;

(iii) details of water levels, including dates and details of fluctuation; and

(iv) four sets of photographs or composite photographs as stated in Clause 8.5.5(a); the photograph of each face shall occupy the full height of an A4 size page.

(c) Records of slope surface stripping shall be kept by the Contractor on Site and

a report shall be submitted to the Project Manager for information within 24 hours of the surface stripping. The report shall contain a detailed geological description of the materials exposed, and details and locations of groundwater seepage.

8.5.6 Drilling rigs for ground investigation

(a) Drilling rigs for ground investigation shall be the hydraulic feed type and shall have a rating of at least 26.5 kW to drive a rotary tool tipped with diamonds or tungsten carbide. Drilling rigs shall be capable of drilling in the specified sizes and to the specified depths without excessive vibration.

(b) The weight of each rig shall be such that a force of 12 kN can be applied to

the drilling bit without movement of the rig.

(c) Drilling rigs shall be capable of providing stable drill-string rotation at speeds of between 50 rpm and 1250 rpm and have a ram stroke length of at least 600 mm. The rigs shall be fitted with a tachometer and a hydraulic feed pressure gauge, both of appropriate scales, and a device for measuring the rate of penetration of the drill strings.


(d) Triplex or similar type pumps shall be used when the flushing medium is water; the pumps shall be equipped with a gear box and shall be capable of delivering up to 2 L/s. The pumps shall incorporate a surge bottle to reduce fluctuations in water pressure and the suction hose shall be fitted with a suitable filter. The pumps shall have a by-pass system allowing full control of water flow at all pump delivery rates.

8.5.7 Drilling equipment for ground investigation

(a) Spare drill bits shall be available for use during drilling.

(b) The size of casings shall be appropriate to the drilling, coring, sampling, testing and other installation requirements.

(c) Core barrels for sampling soil shall be equipped with a sediment catcher tube.

The tube shall have the same external diameter as the core barrel and shall be approximately 0.75 m long.

(d) Casings shall be used to stabilize caving ground. The size of casing and drill

rod in use shall be appropriate to the size of core barrel in use. Casings and drill rods shall be straight and shall be clean at the time of drilling and free from scale, dirt and other loose material.

(e) Only regular lengths of casings and drill rods shall be used and imperial and

metric lengths shall not be mixed.

(f) Short lengths of drill rods shall be used to enable continuous coring to be carried out in such a manner that each core run can be completed within one ram stroke.

(g) Short lengths of casing not exceeding the ram stroke length shall be used to

enable casings to be advanced after each core run where necessary.

(h) Core barrels and drill rods shall be stored on steel frame trestles. 8.5.8 Drilling for ground investigation

(a) Drillholes for ground investigation shall be sunk by rotary methods. The methods and equipment used shall be such that:

(i) the overall hole alignment is within 2% for vertical drillholes and is within

5% of the specified alignment for non-vertical drillholes;

(ii) the soil encountered and the levels at which changes in ground conditions occur can be accurately identified;

(iii) the specified sampling requirements can be achieved;

(iv) in-situ tests can be carried out and field installations can be

incorporated at any depth in the drillhole; and

(v) consistency of measurement and minimal disturbance of the ground is achieved.


(b) Casings shall be advanced concurrently with the removal of material in such a manner that loss of ground is avoided.

(c) Larger casings shall be set concentric with drillholes which are being reamed.

(d) The flushing medium for drilling shall be clean water, air, air mist or air foam;

other substances or materials shall not be introduced into drillholes. The flushing medium for drilling shall be passed through a sedimentation basin and shall either be reused or be discharged to surface drains or natural stream courses. Measures shall be taken to prevent flushing mediums seeping through the ground.

(e) The flushing medium for drilling shall not be discharged to stream courses

which are used as a supply of drinking water. 8.5.9 Sampling from drillholes

(a) Jar samples from drillholes shall be taken from the cutting shoe of each undisturbed sample, from any anomalous material, from each standard penetration test and at other locations as directed by the Project Manager.

(b) All loose material and material disturbed by drilling or in-situ tests shall be

removed from the sides and bottom of the drillhole before each undisturbed sample is taken.

8.5.10 Filling drillholes

(a) Granular fill material of a type reviewed without objection by the Project Manager, or 4:1 cement bentonite grout where directed by the Project Manager, shall be deposited in drillholes for ground investigation and compacted to the same relative compaction as the surrounding ground. The casing shall be gradually withdrawn; the fill material shall be kept above the bottom of the casing during withdrawal. Subsequent depressions in the ground surface shall be filled and reinstated. The drillhole position shall be marked with a metal marker and flag or a 300 mm x 300 mm x 150 mm thick concrete block; the hole number shall be inscribed on the surface and highlighted in red paint.

(b) The Project Manager shall be notified before fill material is deposited in

drillholes and before the casing is withdrawn. The ground surface around drillholes shall be reinstated as soon as practicable after the fill material has deposited and compacted in each drillhole.

8.5.11 Records of drillholes

(a) Records of drillholes for ground investigation shall be kept by the Contractor on Site and two copies of a preliminary drillhole log, stamped PRELIMINARY, shall be submitted to the Project Manager for review within 24 hours after completion of each drillhole. Drillhole logs shall be comprehensive and shall be in a form similar to that shown in Figure 44 of 'Geoguide 2 : Guide to Site Investigation', Hong Kong Government, 1987; soil and rock descriptions shall comply with those stated in the insert titled 'Checklist for Soil Descriptions' and 'Checklist for Rock Descriptions' in 'Geoguide 3 : Guide to Rock and Soil Descriptions', Hong Kong Government, 1988.


(b) Drillhole logs shall be drawn to a constant vertical scale of 1:50 and shall contain the following details:

(i) information shown and in the format in Figure 44 and Paragraphs 40.2.6

(2), (4) and (5) of 'Geoguide 2 : Guide to Site Investigation', Hong Kong Government, 1987;

(ii) reduced levels of groundwater strike, observation well bases,

piezometer tips, and sand filter layers; and

(iii) details of utilities identified in the inspection pit excavated at the drillhole location.

8.5.12 Sampling equipment for ground investigation

Sampling equipment and containers for ground investigation shall comply with BS5930 and the following :

(a) For general purpose open tube samples and thin-walled samples, the sample

tube and cutting shoe shall be free from rust, pitting, burring or any other defect. The use of oil inside the sampler shall be limited to the minimum practical. Each sample tube shall have a unique reference number and the word 'TOP' engraved on its exterior at one end. The sample tube shall be driven with the end marked 'TOP' uppermost. The dimensions, construction and condition of each sample tube, cutting shoe and adaptor head shall be reviewed by the Project Manager prior to sampling. The adaptor head shall be fitted with a ball valve to permit the exit of air or water during driving and to assist in retaining the sample during withdrawal, and it shall have an allowance for over-driving. In soil of low cohesion such as silts and silty fine sands the sampler shall be equipped with a basket core retainer to enhance core recovery.

(b) U100, U76 and U40 thin-walled samplers shall be 102 mm (for U100), 78 mm

(for U76) and 42 mm (for U40) diameter open drive sample tubes made from thin-walled seamless cadmium plated or stainless steel not less than 450 mm (for U100), 350 mm (for U76) and 200 mm (for U40) in length fitted with a cutting shoe tapered at an angle not exceeding 20º. The area ratio of the sampler as defined in Figure 13 of 'Geoguide 2 : Guide to Site Investigation', Hong Kong Government, 1987 shall not exceed 30%.

(c) Piston samplers shall be a thin-walled fixed piston sampler. The piston

sampler shall be capable of operating to a depth of at least 20 m below ground level with no lateral movement during the actual sampling operation. The design and maintenance of the sampler shall be such that a partial vacuum is formed over the retained sample in the tube. The minimum recovered sample length shall be 900 mm. The thin-walled tube shall have an external diameter of 75 mm or 100 mm as directed by the Project Manager. The area ratio of the sampler as defined in Figure 13 of 'Geoguide 2 : Guide to Site Investigation', Hong Kong Government, 1987 shall not exceed 10%.


(d) Mazier samplers shall be a Mazier triple-tube core barrel fitted with a detachable rigid PVC inner tube, 2 mm thick, 74 mm internal diameter by 1000 mm long having a detachable projecting cutting shoe which perforates the soil and insulates the core sample from the drilling fluid. The internal diameter of the projecting shoe should not differ by more than 2 mm. The dimensions of the sampler shall not differ by more than ±0.50 mm from those shown in Table 8.1 basket core retainer shall be fitted at the bottom of the PVC inner tube to assist in recovery of the core. The length of the sample recovered shall not be less than 750 mm. A triple-tube core barrel of alternative design shall be submitted for the Project Manager's review.

(e) Split spoon samplers for the standard penetration test shall be provided with a

thin smooth stainless steel.

Table 8.1: Dimensions of Mazier Core Barrel Sampler

Item Dimension (mm) Inner Barrel Cutting Shoe ID OD

72.0 77.2

Core bit OD 101.1 Liner tube ID 74.0 Inner tube barrel ID OD

78.0 88.5

Outer tube barrel OD 98.5 8.5.13 Sampling for ground investigation

(a) A reference number shall be assigned to each soil sample taken from a drillhole or trial pit. The number shall be unique for that drillhole or trial pit and shall be in order of depth below ground level.

(b) The visible ends of each undisturbed sample shall be trimmed of any

disturbed material immediately after recovery from the ground. The sides of the tube or box shall be cleaned and the ends of the sample shall be coated with three successive thin films of just-molten microcrystalline wax. A metal foil disc or plate shall be added and followed by more molten wax to give a total thickness of at least 20 mm. Any space remaining in the ends of the sample tube or box shall be solidly filled with damp sawdust and the ends of the sample tube shall be covered with tight fitting rubber caps.

(c) Each sample shall be identified by a label. The label shall be written with

permanent ink and protected from moisture, damage and loss. The minimum labelling requirements shall be as follows:

(i) All labels shall contain the following information:

• name of Contract; • name or reference number of the site; • reference number, location and angle of borehole; • reference number of sample; • date of sampling; • brief description of the sample; • depth of the top and the bottom of the sample below ground level;

and • location and orientation of the sample if taken from a trial pit.


(ii) For jar samples, a stick-on label covered with a transparent plastic cover shall be secured with adhesive tape to the body of the jar.

(iii) For undisturbed and bulk samples, a permanent or stick-on label

covered with a transparent plastic sheet shall be secured with adhesive tape to the body of the container. An additional label giving the sample reference number and depth of sample shall be sealed in with the sample.

(iv) For core samples stored in core boxes, a stapled card, stick-on label or

permanent ink shall be used externally on the front of the box and repeated inside. The hole reference number shall be written in permanent ink or paint on each end of the core box.

8.5.14 Storage and delivery of samples for ground investigation

(a) Samples for ground investigation shall be delivered to, and stored at, a core store at a location reviewed without objection by the Project Manager. Samples shall be delivered to the testing laboratory at a time reviewed without objection by the Project Manager.

(b) Undisturbed soil samples shall be stored and delivered in a wooden crate of

appropriate dimensions. The samples shall be kept in an upright position with a separate compartment for each sample. The compartment shall be properly padded and the lower end of the sample shall be placed in the bottom of the compartment.

(c) The samples shall not be disturbed during transportation, handling and

storage.

8.5.15 Bulk samples Bulk samples shall be obtained from undisturbed ground. Each bulk sample shall

be sealed into a metal or plastic container immediately after it has been taken. 8.5.16 Mazier samples Mazier samples shall be taken by a Mazier sampler and in accordance with Clause

8.5.12. 8.5.17 U100 and U76 samples

(a) Sample tubes shall be advanced by jacking action. The jack shall be arranged to align with the sampler. Measures shall be taken to prevent lateral movement during the sampling operation.

(b) Each U100 sample shall contain at least 300 mm net length of undisturbed

material and each U 76 sample shall contain at least 200 mm net length of undisturbed sample.


8.5.18 Block samples

(a) Block samples shall be taken from the sides or bottom of trial pits at locations and orientations determined by the Project Manager.

(b) Each block sample shall be at least 230 mm x 230 mm x 230 mm and shall be

excavated, trimmed, cut, wrapped, waxed and packed in metal or wooden boxes in accordance with the procedure stated in Part A of Des. E-2 of the United States Bureau of Reclamation Earth Manual.

8.5.19 Rock cores

(a) Rock cores obtained from drillholes shall be removed from the core barrel without damage by gentle hammering with a wooden mallet on the side of the core barrel to free wedges pieces; other methods shall not be used.

(b) As the rock core is extruded, it shall be arranged in the box in sequence

starting with the shallowest core on the left side of the box against the hinge and working along the slat and subsequently outwards towards the staple. The depths at which each core run started and finished shall be recorded within the box by painting on wooden blocks which fit between the dividing slats. Fractured rock core shall be spread throughout its length and packed securely. Rock core losses shall be shown by wooden blocks or polystyrene of a square cross section to fill the core box; the length of the wooden block or polystyrene shall be equal to the length of core lost.

8.5.20 Standard penetration tests

(a) The apparatus and procedure for standard penetration tests shall comply with BS1377:1975, Test 19. The drive hammer shall be a type incorporating an automatic trip mechanism to ensure free fall. The 60º solid core shoe shall be used in soil containing coarse gravel.

(b) A thin smooth stainless steel or aluminum liner of 35 mm internal diameter

shall be fitted in the split-spoon sampler during the standard penetration test. After the sampler has been withdrawn from the drillhole, the liner and the retained soil shall be treated in the same manner as an undisturbed sample.

(c) Standard penetration tests shall be carried out below the level of the casing.

The base of the drillhole shall be fully cleaned before the test starts. Jar samples shall be taken from the split-barrel shoe after each test.

(d) The number of blows of the drive hammer required to achieve each 75 mm of

shoe penetration until a total penetration of 450 mm has been achieved shall be recorded. The N-value shall be recorded as the sum of the number of blows of the drive hammer required to achieve the last 300 mm of shoe penetration. The number of blows recorded for the initial 150 mm of shoe penetration shall not be included in the N-value calculation. If any increment of 75 mm of shoe penetration is not achieved after 100 blows of the drive hammer, the number of blows and the penetration achieved shall be recorded and the test shall be terminated.


8.5.21 GEO probe tests

GEO probe tests shall be carried out in accordance with Appendix A8.1. The GEO probe hole shall be sealed with cement grout on completion of the test for at least the top 600 mm of the hole. The grout shall consist of cement and water in the proportions 0.4:1 by mass.

8.5.22 In-situ density tests

(a) In-situ density tests shall be carried out by the sand replacement method in accordance with Clause 7.5.14 (e) and (f).

(b) A jar sample shall be taken at each location where an in-situ density test is

carried out. 8.5.23 Rising and falling head permeability tests

(a) Rising and falling head permeability tests shall be carried out using the apparatus described in Figure 27 of 'Geoguide 2: Guide to Site Investigation', Hong Kong Government, 1987. The method of testing shall be in accordance with Figure 30 of 'Geoguide 2: Guide to Site Investigation', the method of flushing of the bottom of the drillhole stated in Clause 8.5.23(d) shall be used. The type of filter material and sand to be used shall be in accordance with Clause 8.24.10(b), and shall be placed in the drillhole using a tremie pipe.

(b) Rising head permeability tests shall be carried out by lowering the water level

in the standpipe by approximately 3 m. The water level in the standpipe shall be allowed to rise to equalise with the ground water level and the time for each 0.2 m rise in water level shall be recorded.

(c) Falling head permeability tests shall be carried out by raising the water level in

the standpipe by approximately 3 m. The water level in the standpipe shall be allowed to fall to equalise with the ground water level and the time for each 0.2 m drop in water level shall be recorded.

(d) The method of flushing of the bottom of the hole for field permeability tests shall be as follows:

(i) Clean water shall be introduced to the cased hole through a 38 mm

diameter pipe fed from a storage tank. The feed pipe shall contain a perforated section 480 mm in length consisting of 20 rings of holes, at 25 mm centres, each containing 4 holes of 6 mm diameter. The complete perforated section shall be positioned such that it is just below the existing ground water level in the borehole. The end of the perforated section of pipe shall be capped.

(ii) The flushing water shall be withdrawn from the casing through a 38mm

diameter pipe positioned with its open end between 150 mm and 200 mm above the base of the borehole. The discharge shall be by means of a pump of sufficient capacity to extract the flushing water from the base of the borehole. Control of the flow of clean water and discharge water shall be by means of valves positioned on the inflow pipe and the discharge pipe.


8.5.24 Constant head permeability tests

(a) Constant head permeability tests shall be carried out using the apparatus described in Clause 8.5.23(a). Clean water shall be fed into the standpipe at a constant rate and the time for each 0.2 m rise in water level shall be recorded until either a constant water level is established or until the water level is 0.3 m below the top of the casing. The constant rate of inflow which is required to maintain a constant head shall be recorded.

(b) After a constant water level has been achieved as stated by Clause 8.5.24(a),

the cumulative inflow readings required to maintain the constant head shall be recorded in the following sequence:

(i) 4 readings at 15 second intervals;

(ii) 9 readings at 1 minute intervals;

(iii) 4 readings at 5 minute intervals; and

(iv) readings at 10 minute intervals until two consecutive readings differ by

less than 0.5 litre. 8.6 INSPECTION, TESTING AND COMMISSIONING – GROUND INVESTIGATION 8.6.1 Records of in-situ testing

(a) Records of each in-situ test shall be kept by the Contractor on Site. The Project Manager shall be notified before test apparatus is dismantled.

(b) The results of standard penetration tests shall be recorded on drillhole logs as

stated in Clauses 8.5.11 and 8.6.2. (c) The results of GEO probe tests shall be recorded as stated in Clause 8.5.21

and shall be submitted to the Project Manager for review within 24 hours after the test.

(d) The results of in-situ density tests shall be recorded in a form reviewed

without objection by the Project Manager and shall be submitted to the Project Manager for review within 24 hours after the test.

(e) The results of rising, falling and constant head permeability tests shall be

recorded as stated in Clauses 8.5.23 and 8.5.24 and shall be submitted to the Project Manager for review within 24 hours after the test. The results of the rising and falling head permeability tests shall be recorded in the format shown in Figure 30 of 'Geoguide 2 : Guide to Site Investigation', Hong Kong Government, 1987.


8.6.2 Reports for ground investigation

(a) Daily records of ground investigation operations shall be kept by the Contractor on Site and two copies of the records shall be submitted to the Project Manager for review within 3 days after the ground investigation operation to which they refer. The daily records shall contain the following information in a form reviewed without objection by the Project Manager:

(i) Contractor's name, and Contract number, borehole reference number

and inclination, site name, rig type and number, operator, hours worked with times, date, weather, ground level at borehole and measured water levels in the borehole at various times;

(ii) for each sample, drilling or core run for each test, installation or strata

encountered, the following where applicable: • start and finish depths below ground level; • start and finish times; • casing diameter and depth; • bit number and type; • sample reference number and type; • SPT test result in number of blows recorded; • percentage water returns and core recovery; • a description of the soil and rock strata or sample; and • a description of field tests or instruments installed.

(b) A final report on ground investigation operations shall be prepared by the

Contractor and shall be submitted to the Project Manager for review within 15 days after all comments on the preliminary drillhole logs have been received from the Project Manager. The report shall contain the drillhole logs and test records.

8.7 MATERIALS - SLOPE TREATMENT WORKS 8.7.1 Cement mortar

(a) Cement mortar for in-filling joints in rock faces, for bedding rock for masonry infilling and for surfacing slopes shall consist of OPC and sand in the proportions 1:3 by volume.

(b) OPC shall comply with BS 12. (c) Sand shall be natural sand or crushed natural stone complying with BS 1200.

8.7.2 Rock for masonry infilling

Rock for masonry infilling shall not exceed 300 mm in size and shall be obtained from a source reviewed without objection by the Project Manager.


8.7.3 Soil-cement (a) Soil-cement shall consist of OPC, sand and inorganic soil in the proportions

1:3:12 by mass. (b) OPC shall comply with BS 12. (c) Sand shall comply with BS 1200. (d) Inorganic soil shall be free from organic matter and shall contain not more

than 30% of soil particles passing a 63 μm BS test sieve.

8.7.4 Chunam

(a) Chunam for surfacing shall consist of OPC, hydrated lime and inorganic soil in the proportions 1:3:20 by mass.

(b) OPC shall comply with BS 12. (c) Hydrated lime shall comply with BS 890, Type 1. (d) Inorganic soil shall be as stated in Clause 8.7.3(d).

8.7.5 Aggregates for sprayed concrete

The nominal maximum aggregate size of aggregates for sprayed concrete shall not exceed 10 mm.

8.7.6 Reinforcement for sprayed concrete

Fabric reinforcement for sprayed concrete shall comply with BS 4483. 8.7.7 Protective mesh and fixings

(a) Protective mesh for slopes shall be PVC coated galvanized steel wire woven into a double twist hexagonal mesh; each hexagon shall be 80 mm x 60 mm. The steel wire shall be at least 2.2 mm diameter and the PVC coating shall be at least 0.4 mm thick.

(b) Tying wire for protective mesh shall be 2.2 mm diameter PVC coated

galvanized soft annealed steel wire. (c) Bolts for fastening protective mesh to rock shall be galvanized mild steel

hooks as stated in the Contract. (d) Bolts for permanent protective screens shall be galvanized to a minimum

average mass coating of 610 g/m². (e) Galvanizing shall comply with BS 729.


8.7.8 Rock bolts

(a) Rock bolts shall be a proprietary type reviewed without objection by the Project Manager. Rock bolts shall comply with CS2 and shall be mild steel or high yield deformed steel as stated in the Contract. Rock bolts shall be galvanized to a minimum average mass coating of 610 g/m² in accordance with BS 729.

(b) The rated working load of rock bolts shall not exceed 50% of the ultimate

tensile strength. A reduction of 4 mm in the diameter of the bolt shall be taken into account for corrosion when calculating the ultimate tensile strength.

8.7.9 Grout for rock bolts

Grout for rock bolts shall be as stated in Clauses 8.11.2 and 8.14.5 except that the water cement ratio shall not exceed 0.45.

8.7.10 Rock dowels

Rock dowels shall comply with CS2 and shall be high yield deformed steel as stated in the Contract.

8.7.11 Grout for rock dowels

Grout for rock dowels shall be as stated in Clauses 8.11.2 and 8.14.5 with a water cement ratio not greater than 0.45.

8.8 SUBMISSIONS – SLOPE TREATMENT WORKS 8.8.1 Particulars of access

Particulars of the proposed means of access for slope treatment works, including access structures and reinstatement, shall be submitted to the Project Manager for review.

8.8.2 Particulars of sprayed concrete

(a) The following particulars of the proposed materials and methods of construction shall be submitted to the Project Manager for review:

(i) type and performance of mixing and spraying plant;

(ii) details of water sprays and associated pumps for surface spraying;

(iii) method of curing;

(iv) details of trial panels and test panels;

(v) methods of measuring surface temperature and moisture content of the

soil; and

(vi) methods of achieving the specified thickness of sprayed concrete and the specified cover to reinforcement and methods of measuring the thickness and cover after spraying.


8.8.3 Particulars of rock bolts

(a) The following particulars of the materials and methods of construction for rock bolts shall be submitted to the Project Manager for review:

(i) details of rock bolts, anchorages and centralizers;

(ii) methods of tensioning and grouting;

(iii) proposed working loads;

(iv) previous performance records; and

(v) details of equipment for testing rock bolts, including test and calibration

certificates. 8.8.4 Representative samples of materials

A representative sample of a complete rock bolt shall be submitted to the Project Manager for review of the source and type of rock bolt at the same time as particulars of rock bolts are submitted.

8.9 WORKMANSHIP – SLOPE TREATMENT WORKS 8.9.1 Access to slopes

(a) Means of access consisting of materials reviewed without objection by the Project Manager shall be installed to enable the Project Manager to examine slope treatment works. The means shall allow access to within 0.8 m of the slope face; hand and foot holds for climbing shall be provided by members at centres not exceeding 0.5 m vertically and 0.8 m horizontally.

(b) A system of safety ropes shall be installed on the means of access; safety

ropes shall be 12 mm diameter and shall have a breaking force of at least 22 kN. The system of safety ropes shall consist of:

(i) vertical ropes at not more than 3 m centres horizontally securely

anchored to the crest of the slope; and

(ii) horizontal ropes at not more than 3 m centres vertically. The system of safety ropes shall be constructed in such a manner that the ropes are tied at not more than 3 m spacings in both directions to form a net.

8.9.2 Protection fences and barriers

(a) Protection fences and barriers for slope treatment works shall be constructed as stated in the Contract before slope treatment work starts.

(b) Damage to protection fences and barriers shall be repaired immediately. The

Contractor shall notify the Project Manager before protection fences and barriers are dismantled.


8.9.3 Preparation for slope treatment works

(a) Vegetation shall be cleared and existing impermeable surfaces and topsoil shall be removed from existing soil slopes before slope treatment works start.

(b) Loose material shall be removed from the surface of new soil slopes and the

surface shall be trimmed and scarified before slope treatment works start. The surface shall be moistened immediately before the slope surface treatment works start.

(c) Rock faces and joints, and the surface and joints of retaining walls shall be

cleaned of moss, vegetation and loose material, immediately before slope treatment works start, and surplus water shall be removed by an air jet. Water flowing from or across the rock face shall be diverted by relief drains before the application of impermeable surfaces. All vegetation and loose material shall be removed from rock joints. Moss and loose materials shall be removed by wire brushing or scraping.

8.9.4 Scaling and trimming of rock slopes

(a) Scaling and trimming of rock slopes shall be carried out in such a manner that soil and rock is removed from the slope face without affecting the stability and integrity of the slope. Measures shall be taken to prevent uncontrolled falls of debris arising from scaling and trimming works. Scaling and trimming of rock slopes shall be carried out using hand-held tools, pneumatic tools or feather and wedge.

(b) All material removed or excavated by scaling and trimming and loose

fragments of soil and rock shall be removed from the slope. Rock faces shall be cleaned using a water jet coupled to compressed air after scaling and trimming is complete.

8.9.5 Rock splitting

Rock splitting shall be carried out using percussive hammers, drills, hydraulic splitters, chemical expanding agents or hand-tools. Explosive shall not be used.

8.9.6 Removal of boulders

Boulders which are to be removed from slopes shall be broken down by means of line drilling, expansive grouts or rock breakers. Explosives shall not be used.

8.9.7 Sealing and infilling & rock joints

Joints in rock faces shall be sealed with Grade 20/20 concrete, cement mortar or masonry. Rock for masonry infilling shall be bedded in cement mortar. Relief drains directed by the Project Manager shall be installed before rock joints are sealed or infilled.


8.9.8 Concrete buttresses

(a) Concrete for buttresses shall be Grade 20/20 unless otherwise stated in the Contract.

(b) Drainage which is required behind buttresses shall consist of relief drains

connected to 50 mm diameter PVC outlet pipes laid at a gradient of at least 1 in 50; the PVC pipes shall be securely fixed to the formwork before concreting starts.

8.9.9 Mixing soil-cement

Soil-cement shall be thoroughly mixed in a concrete mixer; small quantities of soil-cement shall not be hand mixed. The constituents of the mix shall be as reviewed without objection by the Project Manager on the basis of the results of field trials.

8.9.10 Deposition and compaction of soil-cement fill

(a) Soil-cement fill shall be deposited in its final position and compacted within 30 minutes after the cement has been added to the mix.

(b) Soil-cement fill shall be compacted as stated in Clauses 7.4.26 and 7.4.29,

using the layer thickness and compactive effort successfully demonstrated in the field trials and reviewed without objection by the Project Manager.

(c) The moisture content of the soil cement mix shall not be less than the

optimum value as determined by the vibrating compaction method of BS 1924 : Part 2, nor more than 2% above this optimum value.

(d) The relative compaction of the soil cement fill will be as reviewed without

objection by the Project Manager following review of the results of the field trials, but in any case will not be less than 95% of the maximum dry density for the agreed mix as determined by the vibrating compaction method of BS 1924 : Part 2.

(e) The in-situ density of compacted soil cement fill shall be determined using the

sand replacement method of BS 1924 : Part 2. 8.9.11 Mixing chunam

The cement and lime for chunam shall be mixed dry before adding the soil. The materials shall then be mixed thoroughly, with water sprinkled, until the colour and consistency are uniform.

8.9.12 Placing and compacting chunam (a) Bamboo dowels shall be driven into the face of the slope on which chunam

will be placed at 1.5 m centres on a staggered pitch to leave a 25 mm projection from the slope face to receive the chunam. Bamboo dowels shall be at least 25 mm in diameter and shall be 150 mm long. Bamboo dowels shall not be used on slopes less than 30º to the horizontal.

(b) The chunam shall be laid to a total thickness of 50 mm in two equal layers;

the layers shall be well compacted by ramming. The bottom layer of chunam shall be left with a rough finish to provide bonding for the top layer.


(c) The top layer of chunam shall be thoroughly wetted and rubbed with sacks to fill any cracks immediately before the chunam hardens. The surface shall be sprinkled with water and finished by trowelling to form a smooth uniform surface.

8.9.13 Joints in chunam

Joints in chunam shall be neat and straight and panels shall be rectangular. Joints in the top and bottom layers shall not coincide.

8.9.14 Weepholes in chunam

50 mm diameter PVC weepholes shall be constructed at 1.2 m staggered centres in each direction before chunam is placed; the weepholes shall penetrate at least 50 mm into the soil.

8.9.15 Temporary chunam surfaces

Temporary chunam surfaces to the faces of slopes or excavations shall consist of a single layer of chunam 20 mm thick, without bamboo dowels. Temporary chunam drainage channels shall be constructed by building up the chunam to an appropriate shape or by cutting a channel into the slope and lining with chunam. Temporary chunam shall be removed in stages before deposition of fill material or slope treatment works start.

8.9.16 Preparation of slope surfaces for sprayed concrete

(a) Weak material along joints or seams in slope surfaces to which sprayed concrete will be applied shall be removed to a depth equal to the width of the weak zone.

(b) When the soil surface temperature exceeds 25°C or the moisture content is

less than 10%, the surface to be sprayed shall be watered using sprays. Hoses without sprays shall not be used. Spraying of water onto the slope surface shall be carried out not more than 1 hour before spraying of concrete starts.

8.9.17 Fixing reinforcement

Fabric reinforcement for sprayed concrete shall be fixed securely to the slope by steel nails or rawl bolts and shall be laid without sharp bends or creases. The cover to the reinforcement shall be at least 20 mm and laps between adjacent sheets shall be at least 150 mm.

8.9.18 Weepholes in sprayed concrete

50 mm diameter weepholes shall be constructed at 1.2 m staggered centres in each direction; the weepholes shall extend to the full thickness of the sprayed concrete.

8.9.19 Equipment for spraying concrete

Equipment for spraying concrete shall be the dry mix delivery type with water added at the nozzle. The equipment shall be fitted with weighbatching facilities. The equipment shall be capable of projecting a mixture of cement, fine and coarse aggregate and water at high velocity on to the surface of the slope to produce a dense homogeneous cover.


8.9.20 Spraying concrete

(a) The surface temperature and moisture content of the soil shall be measured, and the results submitted to the Project Manager for review, immediately before sprayed concrete is applied.

(b) The aggregate and sand for sprayed concrete shall be kept dry before mixing.

The water shall be added at the nozzle at the instant of application. The air and water supply, the rate of application and all other factors affecting the quality of the work shall be adjusted to produce dense concrete with no sloughing. Rebound material shall not be reused and shall be removed within 8 hours after spraying.

(c) Sprayed concrete shall be applied in layers not exceeding 50 mm thick to the

total thickness stated in the Contract. The maximum panel dimension shall not exceed 15 m.

8.9.21 Curing sprayed concrete

Sprayed concrete shall be cured for at least 4 days after application by either Method 1, Method 2 or Method 3 as stated in Clause 20.7.15.

8.9.22 Fixing protective mesh for slopes

Protective mesh for slopes shall be suspended down the rock face and bolted into the slope face at 250 mm centres at the top and sides of the mesh and at 5 m intervals at the toe of the slope. Laps in the mesh shall be at least 300 mm and each side of the lap shall be tied at 125 mm centres with galvanised and PVC coated binding wire.

8.9.23 Trials for rock bolts

The design bond length of rock bolts with bonded anchorages shall be determined for each rock type by a pull-out trial. The proof load of a pull-out trial shall be twice the working load. Pull-out trials shall be carried out on two bolts for each combination of rock bolt and rock type. The bolts used in trials shall be discarded and shall not form part of the Permanent Works, and the hole shall be sealed by grouting.

8.9.24 Drilling, preparing and testing rock bolt holes

(a) Holes for rock bolts shall be drilled at the locations and to depths directed by the Project Manager. The diameter of the hole shall be at least 20 mm larger than the diameter of the rock bolt or the outer diameter of the connectors, whichever is larger. The method of drilling shall be rotary or rotary percussive with water flush or air flush accompanied by the operation of an effective dust extraction and filtering device. Holes shall be drilled to provide 50 mm cover to the end of bolts for which cement grout is used to form the bond length.

(b) Holes for rock bolt shall be flushed with clean water before rock bolt

installation starts until the return water runs clear. Standing water shall be blown out from the hole using compressed air after flushing.

(c) Holes for rock bolts shall be tested by the Packer test as stated in Clauses

8.10.11, 8.10.12 and 8.10.13 and the results of the tests shall be submitted to the Project Manager for review, before installation of rock bolts starts.


8.9.25 Fixing rock bolts

(a) The Project Manager shall be notified before installation of rock bolts starts. (b) Rock bolts shall be installed in accordance with the manufacturer's

recommendations. (c) Rock bolts shall be fully grouted after stressing. (d) Installation of rock bolts, including grouting of the free length and installation

of head protection, shall be completed as soon as practicable and not more than 14 days after completion of the drillhole.

(e) Rock bolts with a grouted anchorage shall not be stressed until the grout

crushing strength has attained a value of 21 MPa when tested in accordance with Clauses 8.15.9, 8.15.10 and 8.15.11.

8.9.26 Grouting rock bolts

(a) Grouting for rock bolts shall be in accordance with the requirements stated in Clauses 8.11 to 8.15 except as stated in Clause 8.9.26(b) and (c).

(b) Grout shall be introduced at the lower end of drillholes with downward

inclinations and shall displace all air and water through the top of the drillhole. (c) Packers and return ducts which maintain a head on the grout until the grout

has set shall be used for drillholes with upward inclinations or with inadequate downward inclinations. The packers and ducts shall be such that separate grouting of the anchorage zone and free-length zone of the drillhole can be carried out. The head to be maintained on the grout shall be as reviewed without objection by the Project Manager.

8.9.27 Proving rock bolts

Each installed rock bolt shall be proved as stated in Clauses 8.10.14 to 8.10.16 Rock bolts shall be locked off at 1.1 times the working load after proving. The complete bolt head assembly shall be encased by a concrete block after locking off.

8.9.28 Records of rock bolts

Records of installation of rock bolts shall be kept by the Contractor on Site and a copy shall be submitted to the Project Manager for review within 7 days after each installation operation. Records shall contain the following:

(a) rock bolt identification number;

(b) drilling details, including:

(i) date and time drilling started and finished;

(ii) machine and operator identification;

(iii) location, level, inclination, bearing, length and diameter of drillhole; and

(iv) rate of penetration at 0.5 m intervals;


(c) watertightness of drillhole, including:

(i) date and time water test started and finished;

(ii) details of any pre-grouting and redrilling;

(iii) length of test zone;

(iv) water pressure applied;

(v) duration of test; and

(vi) measured water absorption rate;

(d) details of steel bolts, including:

(i) type and diameter;

(ii) bond length;

(iii) overall length;

(iv) number and type of centralising spacers; and

(v) stressing record and lock-off load;

(e) details of grouting, including: (i) date and time grouting started and finished; (ii) details of any packers used and length of grouted zones;

(iii) head maintained on grout during setting;

(iv) volume of grout accepted; and

(v) identification marks of grout cubes.

8.9.29 Drilling and preparation of rock dowel holes

The drilling and preparation of holes for rock dowels shall be as stated in Clause 8.9.24(a) and (b).

8.9.30 Grouting rock dowels

(a) Grouting for rock dowels shall be in accordance with the requirements stated

in Clauses 8.11 to 8.15 except as stated in Clause 8.9.30(b). (b) Rock dowels shall be grouted over the complete length of the drillhole in

which the dowel is installed. Centralisers shall be fitted to rock dowels before grouting to ensure an even annulus of grout.


8.9.31 Records of rock dowels

Records of installation of rock dowels shall be kept by the Contractor on Site and a copy shall be submitted to the Project Manager for review within 7 days after each installation operation. The records shall contain at least the following details:-

(a) rock dowel identification number;

(b) drilling details, including:

(i) date and time drilling started and finished;

(ii) machine and operator identification;

(iii) location, level, inclination, bearing, length and diameter of drillhole; and

(iv) rate of penetration at 0.5m intervals;

(c) watertightness of drillhole, including:

(i) date and time water test started and finished;

(ii) details of any pre-grouting and redrilling;

(iii) length of test zone;

(iv) water pressure applied;

(v) duration of test; and

(vi) measured water absorption rate;

(d) details of steel dowels, including:

(i) type and diameter;

(ii) bond length;

(iii) overall length; and

(iv) number and type of centralising spacers; and

(e) details of grouting, including:

(i) date and time grouting started and finished; (ii) details of any packers used and length of grouted zones;

(iii) head maintained on grout during setting;

(iv) volume of grout accepted;

(v) identification marks of grout cubes; and

(vi) results of cube tests on grout.


8.10 INSPECTION, TESTING AND COMMISSIONING – SLOPE TREATMENT WORKS 8.10.1 Chunam Surface Trial panel

A trial panel 50 mm thick and at least 3m x 3m shall be constructed for chunam surfaces.

8.10.2 Trial panel

A trial panel at least 50 mm thick and at least 3m x 3m shall be constructed for sprayed concrete on the surface to be treated. The average percentage rebound shall be estimated for each trial panel and shall be used in the calculations of the cement content of the applied concrete.

8.10.3 Inspection of sprayed concrete

Completed areas of sprayed concrete shall be sounded using a wooden mallet; areas which in the opinion of the Project Manager are substandard or hollow shall be removed and resprayed.

8.10.4 Records of sprayed concrete

Records of sprayed concrete operations shall be kept by the Contractor on Site and shall be submitted daily to the Project Manager for review. The records shall contain details of the quantities of all materials used at each location.

8.10.5 Testing: Optimum moisture content and maximum dry density of soil-cement fill

The maximum dry density and optimum moisture content of soil-cement fill shall be tested as stated in Clauses 7.5.7 to 7.5.13 except that the method of testing shall be the Vibrating Hammer Test Method in accordance with BS 1924.

8.10.6 Testing: test panels for sprayed concrete

(a) The strength of sprayed concrete shall be determined from concrete cores cut from a test panel constructed at the same time as sprayed concrete is applied.

(b) One test panel shall be constructed for each area of sprayed concrete of

500m² or part thereof. (c) The test panel shall be 250 mm thick and shall be at least 1 m x 1 m. The

mould shall be securely fixed in position at the same height and inclination as the surface being sprayed. The panel shall be constructed by spraying concrete into the mould at the same time as the concrete to be tested is applied. The test panel shall be cured by the same method as the sprayed concrete.


8.10.7 Samples: concrete cores from sprayed concrete

(a) Three concrete cores shall be provided from each test panel; cores shall not be taken within 125 mm from the edges of the panel.

(b) Concrete cores shall be 100 mm diameter and shall be the full depth of the

test panel. (c) The method of taking concrete cores shall be in accordance with CS 1.

8.10.8 Testing: concrete cores from sprayed concrete (a) Each concrete core shall be tested to determine the compressive strength and

density. (b) The method of preparing and testing the cores to determine the compressive

strength shall be in accordance with CS 1; the method of testing the cores to determine the density shall be in accordance with CS 1. Three concrete cores shall be tested at 28 days.

8.10.9 Compliance criteria: concrete cores from sprayed concrete

The results of tests for compressive strength of concrete cores shall be interpreted in accordance with BS 6089. Adjustments to the measured strength in respect of the age of the core when tested shall not be made. The minimum compressive strength of concrete cores, converted to estimated in-situ cube strength in accordance with BS 6089 shall be 20 MPa at 28 days.

8.10.10 Non-compliance: concrete cores from sprayed concrete

If the result of any test for compressive strength or density of concrete cores from sprayed concrete does not comply with the specified requirements for the property, particulars of proposed changes to the materials, mix design, methods of production or methods of construction shall be submitted to the Project Manager for review; further trial mixes shall be made and further trial panels shall be constructed.

8.10.11 Testing: Packer test

(a) The water loss from drillholes for rock bolts shall be determined by the Packer test. The number of drillholes to be tested will be directed by the Project Manager.

(b) The Packer test shall be carried out on the bond length of the drillhole at a

test pressure of 100 kPa. The method of testing shall be as stated in Clause 8.15.12.

8.10.12 Compliance criteria: Packer test

The water loss determined by the Packer test in the grouted hole shall not exceed 5 Lugeons when measured over a 10 minute period.


8.10.13 Non-compliance: Packer test

If the result of any Packer test on drillholes for rock bolts does not comply with the specified requirements for the test, the drillhole shall be grouted, re-drilled and retested. Grouting, re-drilling and retesting shall be continued until the result of the Packer test complies with the specified requirements for the test.

8.10.14 Testing: rock bolts

Each installed rock bolt shall be tested to determine the loss in stress by applying a test load of 1.5 times the working load for 5 minutes.

8.10.15 Compliance criteria: rock bolts

The loss in stress in installed rock bolts shall not exceed 5% of the test load in 5 minutes.

8.10.16 Non-compliance: rock bolts

(a) If the result of any test for loss in stress of installed rock bolts does not comply with the specified requirements for the test, an additional test for loss of stress shall be carried out on the rock bolt.

(b) If the result of any additional test for loss of stress of installed rock bolts does

not comply with the specified requirements for the test, the rock bolt shall be replaced.

8.11 DEFINITIONS AND ABBREVIATIONS - GROUTING FOR GEOTECHNICAL

WORKS 8.11.1 Ground

Ground, for the purpose of grouting for geotechnical works, is fill material, soil and rock and the interfaces between fill material, soil and rock and any structures.

8.11.2 Grout

Grout, for the purpose of grouting for geotechnical works, is cement grout, cement-sand grout, cement-bentonite grout and proprietary grout reviewed without objection by the Project Manager.

8.11.3 Grouting

Grouting, for the purpose of grouting for geotechnical works, is the mixing and injection of grout through predrilled or preformed holes.

8.11.4 Grouting stage

Grouting stage, for the purpose of grouting for geotechnical works, is the discrete length of drillhole into which grout is to be injected in a continuous operation.


8.11.5 Lugeon

Lugeon is a water loss of 1 litre per minute per metre length of hole tested at an effective pressure of 1 MPa.

8.11.6 Batch: grout for geotechnical works

A batch of grout for geotechnical works is any quantity of grout used for grouting geotechnical works in one continuous operation in one day.

8.12 MATERIALS – GROUTING FOR GEOTECHNICAL WORKS 8.12.1 Materials for grout Materials for grout shall comply with Section 20 except as stated in this Section. 8.12.2 Grout for geotechnical works

(a) Cement grout for geotechnical works shall consist of OPC, sand and water. Admixtures shall not be used.

(b) Sand for grout shall be clean dry sand complying with BS 1200 and shall have

a particle size distribution such that 100% passes a 2 mm BS test sieve and not more than 30% passes a 0.2 mm BS test sieve.

(c) Water for grout shall be clean fresh water having a temperature not exceeding

30°C or less than 5°C. (d) Unless otherwise stated in the Contract, cement grout shall have a minimum

crushing strength of 30 MPa at 28 days.

(e) The amount of bleeding of grout shall not exceed 0.5% by volume 3 hours after mixing or 1.0% maximum when measured at 23 ±2°C in a covered glass or metal cylinder of 100 mm internal diameter and with a grout depth of approximately 100mm. In addition, the water shall be reabsorbed by the grout within 24 hours.

(f) The flow cone efflux time of grout shall not be less than 15 seconds.

8.12.3 Standpipes

Standpipes for grouting shall be standard black metal pipe complying with BS 1387.


8.13 SUBMISSION – GROUTING FOR GEOTECHNICAL WORKS 8.13.1 Particulars of grouting for geotechnical works

(a) The following particulars of the proposed materials and methods of construction for grouting for geotechnical works shall be submitted to the Project Manager for review:

(i) details of drilling, grouting and testing equipment;

(ii) details of grout mix, including admixtures;

(iii) methods of storing, mixing and injecting grout;

(iv) methods of drilling, cleaning, capping and sealing grout holes;

(v) methods of grouting, including grouting stages, order of working and

regrouting methods; and

(vi) methods of controlling surface water, groundwater, leakage and ground movement, including methods of monitoring and instrumentation.

8.14 WORKMANSHIP – GROUTING FOR GEOTECHNICAL WORKS 8.14.1 Drilling for grouting for geotechnical works

(a) Holes in rock for grouting for geotechnical works shall be drilled using rotary or percussion type drills. The tolerance for the holes shall be as stated in Clause 8.5.8(a). Grease and other lubricants shall not be used in the flushing medium or on the rods, except around the threads at the ends of the rods. Drilling methods which result in drill cuttings causing blockages such that grouting cannot be performed satisfactorily shall not be used.

(b) The flushing medium for drilling shall be air, air mist, clean water or air

accompanied by the operation of an effective dust extraction and filtering device.

(c) The minimum size of hole for grouting in rock shall be 40 mm. (d) Holes in soil for grouting for geotechnical works shall be drilled by a method

which is suitable to the ground conditions and which is reviewed without objection by the Project Manager.

(e) The location of all underground obstructions and utilities shall be determined by the Contractor before drilling starts and the drilling pattern shall take account of the location of obstructions and utilities.

(f) Casings required to prevent the collapse of grout holes shall be as stated in Clause 8.5.7. Casings shall be removed immediately before or simultaneously with the grouting or sleeve grouting operation in such a manner that the grout hole will not collapse and the injection of grout will not be hindered.

(g) Grout holes shall be flushed clean with water or compressed air introduced at

the bottom of the hole after drilling is complete. The holes shall be protected with capping pipes or standpipes to prevent subsequent collapse or clogging after flushing.


(h) Grout holes which have been drilled more than one day before grouting of the hole starts shall be reflushed with water or compressed air immediately before grouting is commenced and excess flushing water shall be removed by air jet. Holes drilled in soft ground or in ground other than rock and in which sleeve grouts are proposed as part of the grouting operation shall be sleeve grouted as soon as practicable after drilling.

8.14.2 Standpipes and capping pipes

(a) Grout holes shall be capped after drilling and before grouting. Capping shall be by a suitably sealed grout connection, standpipe or packer. The cap shall seal the hole to prevent contamination or clogging of the hole until grouting operations start.

(b) Standpipes, if stated in the Contract, shall be installed in holes after drilling.

The pipe shall be sealed into the hole using cement grout consisting of OPC and water in the proportions 1:1 by volume.

8.14.3 Monitoring of grouting operations

(a) Instrumentation shall be installed to monitor heave, bulging, settlement, lateral movement, deformation or fracturing of the ground or structures due to grouting operations. Records of monitoring shall be kept by the Contractor on Site and a copy submitted to the Project Manager for review. Arrangements for installing instruments and taking measurements inside and outside the Site shall be made by the Contractor.

(b) The accuracy of the instruments shall be checked before grouting starts and

at regular intervals reviewed without objection by the Project Manager. 8.14.4 Grouting equipment

(a) Standby grouting equipment shall be available at all times and shall be capable of being brought into operation immediately in the event of breakdowns during grouting operations.

(b) Grout mixers shall be high speed colloidal mixers having a rotor speed of at

least 1000 rpm and capable of producing a colloidal grout mix. Mixers shall be fitted with a water volume measuring device for batching purposes.

(c) Holding tanks shall be fitted with an agitator to provide continuous agitation of

the grout at 100 rpm. The tank shall be fitted with a dipstick to allow continuous measurement of the volume of grout in the tank. A 2.36 mm removable screen shall be provided between the tank and the pump or grout lines.

(d) Grout pumps shall be a positive displacement type. Pumps shall be fitted with

bypass valves to allow a standby pump to be brought into operation.


(e) Working pressure gauges shall be accurate to within 3% and shall be calibrated against a test gauge before grouting starts and at weekly intervals. A test gauge with accompanying calibration certificates shall be kept on Site for the purpose of calibrating working gauges. Working gauges shall be numbered and a record shall be kept of gauge number, shifts worked, calibration dates and repairs undertaken; records shall be kept on Site and shall be available for inspection by the Project Manager at all times.

(f) Packers shall be such that they seal holes in rock at the specified level and

shall be capable of withstanding the maximum grout or water pressure to be used at that level without leakage. Packers shall be of the mechanical or inflatable rubber type. A sufficient number of packers of a size to suit the holes shall be available on Site.

(g) Grout hoses shall be of sufficient length and shall be arranged in such a

manner to allow continuous circulation of the grout from the pump to the hole and back to the agitator and holding tank. Circulation hose lengths shall be kept to a minimum and sufficient spare hose shall be available in the event of ruptures.

8.14.5 Mixing grout

(a) Grout for geotechnical works shall be batched by weight. The mix proportions may be adjusted if permitted by the Project Manager depending on the results of the trial grouting, water tests in the hole or the results of previously grouted holes.

(b) Grout shall be mixed by adding approximately two-thirds of the cement to the

water adding any admixture and adding the remaining one-third of cement. Other mixing procedures shall not be used.

(c) The time for which grout shall be mixed in high speed mixers shall be suitable

for the type of mixer used. Grout shall be continuously agitated in a holding tank after mixing and shall be screened before being circulated in the grout lines. Mixed grout shall be continuously circulated in such a manner that grout which is not taken in a hole can be returned to the holding tank.

(d) Grout to which a retarding agent has not been added, and which is not used

within 2 hours after mixing, shall not be used for grouting. 8.14.6 Pressure grouting

(a) Holes in rock shall be grouted in grouting stages not exceeding 3 m. Grouting shall be carried out in either an upstage or a downstage sequence.

(b) Ground other than rock shall be grouted in such a manner that grout can be

injected at various points along the grout hole in a multi-stage operation. The grouting method shall employ perforated pipes with rubber sleeve valves.

(c) Grouting pressures shall initially be 100 kPa per 4 metre depth of hole and

shall not exceed the overburden pressure. (d) Holes shall be grouted in a continuous operation at the grouting stages and

pressures stated in the Contract. Grouting shall be carried out by injecting the grout under pressure into each grouting stage of the hole until the grouting stage refuses to take further grout.


(e) If grouting of any hole or grouting stage has not been completed due to excessive grout takes, low pressures, excessive leakage or other causes, the hole shall be redrilled or flushed out with water and re-injected with grout.

8.14.7 Loss or leakage of grout

(a) If during the grouting of any hole, grout is found to flow from adjacent grout holes in quantities which interfere with the grouting operation or to cause appreciable loss of grout, the holes shall be temporarily capped. If capping is not essential, ungrouted holes shall be left open to allow air and water to escape.

(b) If during the grouting of any hole grout is found to flow from joints in the

geological formation at the Site or any other location, the leaks shall be plugged or caulked in a manner reviewed without objection by the Project Manager.

(c) If during the grouting of any hole the grout take increases suddenly by a

significant amount, the Project Manager shall be notified immediately. 8.14.8 Making good holes

(a) Grout holes through concrete shall be made good using concrete reviewed without objection by the Project Manager. The concrete shall be firmly compacted and shall be finished to match the adjacent surface.

(b) Uncapped holes in rock shall be topped up after grouting using cement grout

consisting of OPC and water in the proportions 1:1 by volume, or 1:3 cement sand mortar.

8.15 INSPECTION, TESTING AND COMMISSIONING – GROUTING FOR

GEOTECHNICAL WORKS 8.15.1 Trials for grouting

A grouting trial shall be carried out. The extent and depth of holes for grouting trials and the tests to be carried out shall be as stated in the Contract or as directed by the Project Manager.

8.15.2 Records of grouting for geotechnical works

(a) Records of grouting for geotechnical works shall be kept by the Contractor on Site and shall be available for inspection by the Project Manager at all times. Records shall include the following details:

(i) hole location and reference number;

(ii) depth of hole;

(iii) type of grout and grout mix proportions;

(iv) volume of grout injected;


(v) grouting pressures; and

(vi) times and details of any interruptions, leakages and equipment malfunctions.

(b) A record of grouting for each hole shall be submitted to the Project Manager

for review within 24 hours after completion of grouting of the hole. The record shall contain the following details:

(i) hole location and reference number; (ii) grouting stage numbers and lengths;

(iii) collar level and hole inclination;

(iv) details of grout injections including the information stated in Clause

8.25.7(a); and

(v) details of the grouting procedure, including any stoppages, leaks to other holes, surface leaks and ground movement.

(c) A record of the testing for each hole, including test results, shall be submitted

to the Project Manager for review within 24 hours after completion of testing of a hole. Records of Packer tests shall contain the following details:

(i) hole location and reference number;

(ii) depth of packer in the hole;

(iii) date and time of test;

(iv) type of gauge or meter and identifying reference number;

(v) test readings for each 5 minute period;

(vi) calculated test results in Lugeons; and

(vii) details of any equipment malfunctions, sudden water losses or

blockages, surface leakage or other variations in test procedure.

(d) A report of grouting for each part of the Works as stated in the Contract, including record drawings and logs of holes, shall be submitted to the Project Manager for review within one week after completion and testing of grouting for that part of the Works. The form of records, logs and record drawings shall be submitted to the Project Manager for review.

8.15.3 Samples: bleeding of grout

(a) One sample of grout shall be provided from each batch of grout for geotechnical works to determine the amount of bleeding of the grout.

(b) Samples shall be provided not more than 30 minutes after the grout has been

mixed and shall be protected from moisture content changes before the tests for amount of bleeding are carried out.


8.15.4 Testing: bleeding of grout (a) Each sample of grout taken as stated in Clause 8.15.3 shall be divided into

three specimens; each specimen shall be tested to determine the amount of bleeding.

(b) Grout for geotechnical works shall be tested for bleeding in accordance with

Clause 21.6.24. 8.15.5 Non-compliance: bleeding of grout

If the result of any test for amount of bleeding of grout for geotechnical works does not comply with the specified requirements for amount of bleeding, particulars of proposed changes to the materials, grout mix or methods of production shall be submitted to the Project Manager for review; further grouting trials shall be carried out.

8.15.6 Samples: flow cone efflux time of grout

One sample of grout shall be provided from each batch of grout for geotechnical works to determine the flow cone efflux time of the grout.

8.15.7 Testing: flow cone efflux time of grout

Each sample of grout taken as stated in Clause 8.15.6 shall be tested to determine the flow cone efflux time. The method of testing shall be in accordance with Appendix A8.2.

8.15.8 Non-compliance: flow cone efflux time of grout

If the result of any test for flow cone efflux time of grout does not comply with the specified requirements for flow cone efflux time, particulars of proposed changes to the materials, grout mix or methods of production shall be submitted to the Project Manager; further grouting trials shall be carried out.

8.15.9 Samples: crushing strength of grout

(a) One sample of grout shall be provided from each batch of grout for geotechnical works to determine the crushing strength of the grout.

(b) Samples shall be provided not more than one hour after the grout has been

mixed and shall be protected from moisture content changes before test cubes are made.

8.15.10 Testing: crushing strength of grout

(a) Nine 100 mm test cubes shall be made from each sample of grout taken as

stated in Clause 8.15.9. Three test cubes shall be tested to determine the crushing strength at 3 days, three test cubes shall be tested to determine the crushing strength at 7 days and three test cubes shall be tested to determine the crushing strength at 28 days.

(b) The method of making, curing and testing the test cubes shall be as stated in

Clause 20.8.12(b), (c) and (d).


8.15.11 Non-compliance : crushing strength of grout

If the result of any test for crushing strength of grout for geotechnical works does not comply with the specified requirements for grout, particulars of proposed changes to the materials, grout mix or method of production shall be submitted to the Project Manager for review. Further trial mixes shall be made and further grouting trials shall be carried out.

8.15.12 Testing: Packer tests

(a) The water loss from drillholes for grouting and from grouted and regrouted drillholes shall be determined by the Packer test.

(b) The number of drillholes for grouting to be tested to determine the water loss

shall be proposed by the Contractor and reviewed without objection by the Project Manager.

(c) Every grouted drillhole and every regrouted drillhole shall be tested to determine the water loss.

(d) Packer tests shall be carried out in accordance with BS 5930, Chapter 21.5,

and Clauses 8.15.12(e) to (h). (e) Tests shall be carried out using clean water, in grouting stages not exceeding

3 m in length. The rate of flow of water in the test shall be determined to an accuracy of 10% for flows exceeding 1 L/min.

(f) The test pressure shall be equal to the overburden pressure and shall not

exceed the specified maximum grouting pressure for the grouting stage being tested.

(g) The test shall be carried out between a packer and the base of the hole for

grouting stages at the base of a hole and shall be carried out between two packers in other cases.

(h) The test shall be carried out by pumping water at the specified pressure into

the grouting stage being tested and measuring with a volume meter the water loss over three consecutive 10 minute periods. The result shall be calculated in Lugeons for each 10 minute period.

8.15.13 Compliance criteria : Packer tests

The water loss determined by the Packer test in the grouted hole shall not exceed 5 Lugeons when measured over a 10 minute period.

8.15.14 Non-compliance: Packer test on drillholes for grouting

If the result of any Packer test on drillholes for grouting does not comply with the specified requirements for the test, the drillhole shall be grouted, re-drilled and retested. Grouting, re-drilling and retesting shall continue until the result of the Packer test complies with the specified requirements for the test.


8.15.15 Non-compliance: Packer test on grouted and regrouted drillholes

If the result of any Packer test on grouted drillholes or regrouted drillholes does not comply with the specified requirements for the test, the grout shall be removed and the drillhole shall be regrouted and retested. Removal of grout, regrouting and retesting shall continue until the result of the Packer test complies with the specified requirements for the test.

8.16 DEFINITIONS AND ABBREVIATIONS - GROUNDWATER DRAINAGE AND

CONTROL 8.16.1 Caisson drain

Caisson drain is an excavated vertical shaft, with or without raking drains, to provide drainage by intercepting and lowering the groundwater level in the vicinity.

8.16.2 Geotextile filter

Geotextile filter is a permeable sheet of synthetic material used like a granular filter for filtration and in-plane drainage.

8.16.3 Filter pipe

Filter pipe is a perforated or non-perforated pipe used for draining groundwater. 8.16.4 Granular filter

Granular filter is a graded sand or gravel placed against soil to prevent the migration of fine particles out of the soil caused by water flow, and graded such that free discharge of water flowing into the filter is allowed.

8.16.5 Prefabricated band drain

Prefabricated band drain is a synthetic drain which, when installed in a soil strata, acts as a drainage medium for dissipation of pore water pressure.

8.16.6 Raking drain

Raking drain is a drillhole, with or without perforated filter pipes and geotextile filter sheath, installed generally at an upward inclination for groundwater lowering by gravity flow.

8.16.7 Relief drain

Relief drain is a synthetic drain installed on slope surfaces or in excavations to divert water seepage before applying sprayed concrete, chunam, masonry dentition or other construction.

8.16.8 Trench drain

Trench drain is a trench wholly or partly filled with granular material or clean crushed rock, with or without filter pipes and geotextile filter.


8.17 MATERIALS – GROUNDWATER DRAINAGE AND CONTROL 8.17.1 Granular filter material

Granular filter material for granular filter, trench drains and caisson drains shall consist of durable, inert, natural material free from clay, organic material and other impurities. Granular filter material shall have the particle size distribution stated in the Contract.

8.17.2 Geotextile filter

Geotextile filter shall be a proprietary type reviewed without objection by the Project Manager and unless otherwise stated in the Contract shall have the following properties :

- Trapezoidal tear resistance (ASTM D4533-85) : 0.225kN; - CBR puncture resistance (DIN 54307) : 1.0kN;

- Piping limit : non-cohesive soil : 090 ≤ D85 Soil; and : cohesive soil : 090 ≤ 0.12mm; and - Permeability limit : 090 ≥ D15 Soil; and : 090 ≥ 0.05mm. where :-

090 is the pore size below which lies 90% of the pore sizes in the geotextile; D85, D15 is the particle sizes below which lie 85% and 15% by weight of the soil to be

filtered (only fraction smaller than 5mm to be considered) 8.17.3 Filter pipes

(a) Filter pipes shall comply with the following: Precast concrete pipes : BS 5911 Vitrified clay pipes : BS 65 DI pipes : BS 4772 Steel pipes : BS 534 Porous concrete pipes : BS 1194 Perforated concrete pipes : BS 5911 Pitch fibre pipes : BS 2760 UPVC pipes : BS 4660 or BS 3506 Corrugated polyethylene tubing : AASHTO Designation M252


(b) Class O UPVC pipes shall not be used. (c) The perforations in perforated pipes shall be cleanly cut and shall be uniformly

spaced along the length and circumference of the pipe. (d) UPVC plastic pipes shall be jointed by couplers.

8.17.4 Raking drains

(a) Type O raking drains shall be unlined raking drains; drain holes shall be at least 40 mm diameter.

(b) Type 1 raking drains shall be single pipe raking drains consisting of a single

perforated pipe with a non-perforated invert. (c) Type 2 raking drains shall be single pipe raking drains consisting of a single

perforated pipe with a non-perforated invert and enclosed within a geotextile filter sheath.

(d) Type 3 raking drains shall be double pipe raking drains consisting of an outer

permanent pipe and an inner removable pipe enclosed within a geotextile filter sheath; the outer and inner pipes shall be perforated pipes with a non-perforated invert.

(e) Pipes for raking drains shall be as stated in Clause 8.17.3 (a) and (b); the

openings and slots in pipes with non-perforated inverts shall cover approximately two-thirds of the circumference of the pipe.

(f) Geotextile filter sheaths for raking drains shall be formed of woven or

non-woven geotextile filter complying with Clause 8.17.2.

8.17.5 Fill material for trench drains

(a) Fill material to be used with geotextile filter in trench drains shall be clean crushed rock. Type A and Type B fill material shall have the particle size distributions stated in Table 8.2.

(b) Fill material passing a 425 μm BS test sieve shall be non-plastic. (c) The D15 particle size of Type A fill material for use with perforated pipes shall

be at least 15% larger than twice the maximum dimension of the perforations, where D15 is the equivalent sieve size in millimetres, interpolated from the particle size distribution curve, through which 15% of the fill material would pass.

(d) The Contractor shall check if the fill material to be used as a filter medium is in

the following relationship with the base soil, including any necessary soil testing:-

(i) D15Fc shall be less than 5 x D85Sf.

(ii) D15Ff shall be greater than 5 x D15Sc.

(iii) Uniformity Coefficient )(D10FD60F shall be greater than 4 and less than 20.


(iv) Material shall not be gap graded.

(v) All material shall be less than 50 mm in size.

(vi) Not more than 5% of the material shall pass the 63 micron sieve and that fraction shall be cohesionless.

(vii) Within 48 hours of completion of the checking and testing, the

Contractor shall submit to the Project Manager the results of these checks and tests.

Legend (I) D15F is used to designate the fifteen percent size of the filter

material, that is, the size of the sieve that allows fifteen percent by weight of the filter material to pass through. Similarly, D85S designates the size of sieve that allows eighty-five percent by weight of the base soil to pass through. The subscript ‘c’ denotes the coarse side of the envelope; the subscript `f' denotes the fine side.

(II) If the filter grading Type A or B in Table 8.2 does not satisfy

Clause 8.17.5(d), the Contractor shall design the filter material so as to comply with this Clause. The Contractor shall submit the relevant details to the Project Manager at least four weeks in advance of the commencement of laying of filter material on Site.

(III) The Contractor shall also design the filter so as to prevent filter

material being washed into the pipe as defined in Clause 8.17.5(c).

(e) Filter material shall be placed and compacted in such a manner as to avoid

segregation of the various grain sizes.

Table 8.2: Particle Size Distribution of Fill Material for Trench Drains

Type of fill material

Percentage by mass passing BS test sieve 63 mm 37.5 mm 20 mm 10 mm 3.35 mm 600 μm 63 μm

Type A - 100 - 45-100 25-80 8-25 0 – 5 Type B 100 85-100 0-20 0-5 - - -

8.17.6 Caisson liners

Caisson liners shall be concrete tapered rings at least 100 mm thick and not exceeding 1 m deep. The liners shall be constructed with well-compacted concrete of Grade 20/20 or greater.

8.17.7 Prefabricated band drains

(a) Prefabricated band drains shall consist of a core and a filter. The drains may be manufactured as a single unit or the filter may be wrapped around the core, and overlapped and sealed to contain the core. The drains shall be made from chemically treated paper, polyethylene, polyester, polyolefine or other synthetic material or combination of such materials.


(b) Prefabricated band drains shall be provided with an outer casing or mandrel of rhomboidal or rectangular cross section for use during installation. The drains shall also be provided with an anchor to ensure embedment of the drain during extraction of the mandrel.

(c) The strength of the materials in prefabricated band drains shall be such that

the drains will withstand all forces resulting from handling and installation. (d) The filter jacket for prefabricated band drains shall be a type which:

(i) has been previously proved effective under similar soil and pressure

conditions,

(ii) is in all cases able to prevent excessive migration of soil particles into the core, and

(iii) has a permeability not less than that of the surrounding soil.

(e) Prefabricated band drains shall be able to conform to soil deformation without

buckling or crimping of the core. (f) Prior to the installation of the drains within the designated areas, the

Contractor shall demonstrate that his equipment, method and materials produce a satisfactory installation in accordance with the Specification. The Contractor shall install trial drains at locations designated by the Project Manager.

(g) The end of each drain shall be provided with a suitable disposable shoe of an

acceptable type to ensure that the drain is securely anchored at its base level. 8.18 SUBMISSIONS – GROUNDWATER DRAINAGE AND CONTROL 8.18.1 Particulars of granular filters

(a) The following particulars of the proposed materials and methods of construction for granular filters shall be submitted to the Project Manager for review: (i) whether granular filter material is to be supplied ready mixed or is to be

mixed on the Site;

(ii) source of supply, including name of supplier of ready mixed material;

(iii) quantity of each constituent if the material is to be mixed on Site;

(iv) Contractor's Equipment and methods of mixing for material mixed on Site;

(v) method of storage and location of storage areas on Site;

(vi) methods of deposition and compaction of material; and

(vii) results of three tests for particle size distribution of the fill material

against which the granular filter is to be placed.


8.18.2 Particulars of geotextile filter

(a) The following particulars of the proposed materials and methods of construction for geotextile filter shall be submitted to the Project Manager for review:

(i) manufacturer's name and source of supply;

(ii) details of geotextile filter including manufacturer's literature;

(iii) a certificate for the geotextile filter showing the manufacturer's name,

the date and place of manufacture and showing that the geotextile filter complies with the requirements stated in the Contract, and including results of the following tests :

- particle size distribution of sub-grade (BS 1377 : 1975 : Part 3); and - determination of pH of sub-grade and sub-ballast (BS 1377 : 1975 :

Part 2);

(iv) calculations showing that the geotextile filter complies with the filtration characteristics stated in the Contract;

(v) details of previous uses of the geotextile filter;

(vi) details of quantities to be supplied in each delivery;

(vii) method of storage;

(viii) methods of cutting and jointing geotextile filter;

(ix) method of repairing small batches; and

(x) methods of laying and holding in position.

8.18.3 Particulars of trench drains

(a) The following particulars of the proposed materials and methods of construction for trench drains shall be submitted to the Project Manager for review: (i) method of excavation of trench and installation of geotextile filter;

(ii) details of granular fill material as stated in Clause 8.17.5; and

(iii) details of geotextile filter as stated in Clause 8.18.2.


8.18.4 Particulars of raking drains

(a) The following particulars of the proposed materials and methods of construction for raking drains shall be submitted to the Project Manager for review:

(i) method of connecting adjacent sections of pipes;

(ii) proportions of sealant mix; and

(iii) details of geotextile filter sheath.

8.18.5 Particulars of relief drains

(a) The following particulars of the proposed materials and methods of construction for relief drains shall be submitted to the Project Manager for review:

(i) details of relief drains and outlets; and

(ii) method of fixing relief drains to the slope face.

8.18.6 Particulars of caisson drains

(a) The following particulars of the proposed materials and methods of construction for caisson drains shall be submitted to the Project Manager for review:

(i) methods of excavation and installation and removal of caisson liners;

(ii) method of compaction of fill material;

(iii) details of granular filter material as stated in Clause 8.18.1; and

(iv) details of geotextile filter as stated in Clause 8.18.2.

8.18.7 Particulars of prefabricated band drains

(a) The following particulars of the proposed materials and methods of construction for prefabricated band drains shall be submitted to the Project Manager for review: (i) details of type of drain, including manufacturer's literature;

(ii) a certificate showing the manufacturer's name, the date and place of

manufacture and showing that the drains comply with the requirements stated in the Contract;

(iii) details of previous installations by the Contractor using similar drains;

(iv) method of installation; and

(v) details of installation mandrel, drain anchor, method of penetration and

method of recording depth of installation.


(b) Subject to a satisfactory installation of trial drains the Contractor shall submit to the Project Manager for review the following particulars of his proposal:-

(i) a detailed layout of drains with reference numbers, which shall comply

with the spacing requirements shown on the Employer’s Drawings. In his proposed layout, the Contractor shall take into account all foreseeable obstructions to the installation of drains (e.g. transition pile caps, retaining wall etc) and shall include proposals to revise the area limits of drains as necessary to avoid such obstructions;

(ii) the base level of each vertical drain which shall comply with the

requirements shown on Employer’s Drawings; and

(iii) the supporting calculations and ground investigation logs on which his proposal is based.

(c) The Contractor shall carry out confirmatory drilling before the installation of

pneumatic piezometer tips and drains.

8.18.8 Particulars of filter pipes

(a) The following particulars of the proposed materials and methods of construction for filter pipes shall be submitted to the Project Manager for review: (i) details of type of pipes, including manufacturer's literature;

(ii) a certificate showing the manufacturer's name, the date and place of

manufacture and showing that the pipes comply with the requirements stated in the Contract;

(iii) details of previous installations by the Contractor using similar pipes;

and

(iv) method of installation. 8.18.9 Particulars of groundwater control, drawdown and monitoring

(a) The following particulars of the proposed materials and methods of construction for groundwater control, drawdown and monitoring shall be submitted to the Project Manager for review :- (i) Contractor's Equipment and materials for dewatering; (ii) timing and sequence of dewatering operations;

(iii) details of silt traps;

(iv) methods of monitoring flow rates and volumes of silt, including

monitoring intervals; and

(v) methods and locations for discharging groundwater.


8.18.10 Representative samples of materials

Representative samples of the following proposed materials shall be submitted to the Project Manager for review at the same time as particulars of the material (Clause 8.18.9) are submitted:

(a) granular filter material; (b) geotextile filter and two pieces of geotextile filter joined in accordance with the

manufacturer's recommendations for each type of joint; and (c) relief drains.

8.18.11 Handling and storage of granular filter material

(a) Granular filter material shall not be handled or stored in a manner which will result in mixing of the different types and sizes or in segregation, contamination, deterioration or erosion of the material.

(b) Stockpiles of granular filter material shall be placed on well-drained, prepared

areas and shall be separated by dividing walls of sufficient height to keep the different materials separate.

8.18.12 Delivery and storage of geotextile filter

(a) Geotextile filter shall be delivered in secure wrappings to ensure that the geotextile filter is dry and protected from damage, contamination and exposure to conditions which may adversely affect it.

(b) Geotextile filter shall be stored on a level surface and shall be kept in a secure

and dry condition, which will not result in damage to the fabric or in contamination of the fabric.

(c) Geotextile filter which is damaged shall not be used in the Permanent Works.

8.18.13 Storage of filter pipes

Coils of plastic tubing for filter pipes shall be stored flat.

8.18.14 Delivery and storage of prefabricated band drains

(a) Prefabricated band drains shall be supplied in rolls, securely packed in light-proof wrappings.

(b) Prefabricated band drains shall be stored in a clean, dry environment.

8.19 WORKMANSHIP – GROUNDWATER DRAINAGE AND CONTROL 8.19.1 Mixing granular filter material

Granular filter material shall be thoroughly mixed by the method reviewed without objection by the Project Manager. Material which has been stockpiled shall be remixed before deposition.


8.19.2 Deposition and compaction of granular filter material (a) Granular filter material shall be deposited and compacted as stated in

Clauses 7.4.20 to 7.4.29. (b) Granular filter material shall be deposited in a manner which will not result in

segregation or contamination of the material. (c) Granular filter material shall be deposited in such a manner that a continuous

free draining zone is formed. The surface of each layer shall be cleaned and scarified before the next layer is deposited.

8.19.3 Damage to geotextile filter

(a) The total period for which geotextile filter is exposed to daylight or other sources of ultra-violet radiation during handling, delivery, storage and installation shall not exceed 7 days.

(b) Geotextile filter which has been damaged or exposed to daylight or other

sources of ultra-violet radiation for longer than the period stated in Clause 8.19.3(a) shall not be used in the Permanent Works.

(c) Repairs to geotextile filter which has been torn or damaged during installation

shall be carried out using a patch of the same material extending at least 300 mm beyond the edge of the damaged area. Repairs shall not be carried out on geotextile filter which has been damaged during storage or storage before installation.

8.19.4 Laying geotextile filter

(a) Geotextile filter shall be installed in such a manner that the individual yarns, webs or layers of the fabric retain their intended orientation and relative positions with respect to each another.

(b) Geotextile filter shall be installed, cut and jointed in accordance with the

manufacturer's recommendations. (c) Fabric reinforcement stated in the Contract not to be jointed shall be lapped

by at least 300 mm. 8.19.5 Protection of geotextile filter

Contractor's Equipment and other vehicles shall not operate on installed geotextile filter unless it is adequately protected by a cover of fill material.

8.19.6 Installation of raking drains

(a) The length of raking drains assembled before installation shall not exceed 12.5 m. Connections between adjacent pipes shall be secured in such a manner that the cumulative longitudinal extension of a 12.5 m assembled length of pipe does not exceed 5 mm when pulled by hand.


(b) Pipes for Type 2 and Type 3 raking drains which are to be wrapped in a geotextile filter sheath shall be placed along the centre of a strip of geotextile filter of sufficient width to allow a lap of at least 50 mm. The strip of geotextile filter shall be drawn around the pipe and fixed to the pipe along the pipe invert with non-metallic ties at 300mm centres to prevent dislocation during installation. The ends of pipes shall be marked to ensure that the impermeable invert is correctly positioned during installation.

8.19.7 Drilling for raking drains

(a) Drilling lubricants other than clean air or fresh water shall not be used for drilling holes for raking drains. Casings shall be used to prevent collapse of the hole and to permit unobstructed insertion of the pipes and geotextile filter sheath.

(b) The drillhole entry point shall be positioned within a tolerance of ±75 mm.

Deviation in alignment shall not exceed 1 in 20. Deviation from straight shall not exceed 20 mm in any 3 m length of drillhole. A positive gradient shall be maintained throughout the complete length of the hole. The inclination of holes shall be measured by a method reviewed without objection by the Project Manager.

(c) Drilling and sampling for undisturbed soil samples and rock cores directed by

the Project Manager to be recovered from drillholes shall be as stated in Clauses 8.5.6 to 8.5.19.

(d) Drillholes shall be temporarily plugged or otherwise protected to prevent entry

of deleterious material after drilling. 8.19.8 Excavation for trench drains

The width of trench drains shall be at least 450 mm. The width of trench drains with filter pipes not exceeding 150 mm diameter shall be at least four times the nominal diameter of the pipe. The width of trench drains for pipes exceeding 150 mm diameter shall be at least the same as the external diameter of the pipe plus 450 mm.

8.19.9 Geotextile filter surround for trench drains

Geotextile filter surround for trench drains shall be installed as stated in Clause 8.19.4.

8.19.10 Bed for trench drains

(a) Concrete bed for filter pipes in trench drains shall be at least 75 mm thick and

shall be Grade 20/20 concrete. (b) Granular bed for filter pipes for trench drains shall have a thickness at least

the same as the diameter of the pipe or 150 mm, whichever is greater.


8.19.11 Deposition and compaction of fill material for trench drains

(a) The material for granular bed for trench drains shall be deposited in the trench in layers not exceeding 150 mm thick and for the complete width of the trench. Each layer shall be compacted with six passes of a plate vibrator or by other method reviewed without objection by the Project Manager.

Trench drains shall be backfilled with Type A or Type B material of Table 8.2. Type A or Type B material shall consist of hard, clean, crushed rock, crushed slag or gravel having a grading within the limits of Table 8.2. The aggregate crushing value of the material shall not exceed 30 per cent. The material passing the 425 μm BS sieve shall be non-plastic when tested in accordance with BS 1377.

(b) Fill material around filter pipes in trench drains shall be deposited and compacted as stated in Clauses 7.4.20(b) and (c) and 7.4.27. The Project Manager shall be notified before fill material is deposited around filter pipes.

8.19.12 Fixing relief drains

Relief drains shall be fixed in position before surface protection or remedial measures are applied. Fixing shall be carried out in a manner which will not affect the serviceability of the relief drains or outlets. Water collected in relief drains shall be discharged to outlets reviewed without objection by the Project Manager.

8.19.13 Construction of caisson drains

(a) Excavation for caisson drains shall be carried out by manual methods in

stages not exceeding 1.0 m depth. Dewatering shall be carried out for excavation below the groundwater level so that work shall be carried out, as near as practicable in the circumstances, in dry conditions. Dewatering shall be carried out as stated in Clauses 8.19.16 and 8.19.17.

(b) The caisson drain shaft shall be supported at all times during construction

using concrete liners. Voids between liners and excavated faces shall be filled with no fines concrete. Caisson liners for each 1.0 m stage shall be installed on the same day as that stage is excavated.

(c) Softened and loose material shall be removed from the base of the caisson

drain immediately before granular filter material is deposited in the caisson drain.

(d) Part or all of the concrete liner adjacent to the granular filter layer shall be

removed before granular filter material or fill material is deposited. Debris from the concrete liner shall be removed from the caisson drain.

(e) Granular filter material shall be deposited in layers not exceeding 500 mm and

shall be compacted by methods reviewed without objection by the Project Manager.

8.19.14 Discharge of water from caisson drains

Water collected in caisson drains shall be discharged to the outlets stated in the Contract or reviewed without objection by the Project Manager


8.19.15 Installation of prefabricated band drains

(a) The installed location of prefabricated band drains shall be within 300 mm of the specified location in plan on the ground surface and the drain shall be within 2% of the installed length to the vertical.

(b) Each prefabricated band drain shall be installed in one continuous length

without joints. (c) The depth of penetration of prefabricated band drains shall be as stated in the

Contract, modified as directed by the Project Manager during installation based on the resistance of the soil to penetration. The Contractor shall notify the Project Manager immediately of any sudden change in the penetration resistance to the mandrel.

(d) Augering, hammering, vibration or other methods may be used to assist vertical

drain installation through the filter drains and the reclamation fill. Such augering, hammering, vibration or other methods shall not extend into the underlying marine clay stratum.

(e) Where obstructions above the marine clay stratum are encountered which

cannot be penetrated using normal and accepted procedures mentioned above, the Contractor shall complete the drain from the elevation of the obstruction to its top level and notify the Project Manager. At the discretion of the Project Manager, the Contractor shall then install a new drain at a location as directed by him.

(f) The Contractor shall keep daily records of the drains installed. Copies of these

shall be submitted to the Project Manager on the day following the installation. The records shall give the date, the reference no. of each drain and the depth of placement below its top level. Brief notes on any unexpected conditions or problems encountered shall be included.

8.19.16 Drawdown of groundwater table

The groundwater table shall not be drawn down to more than 2 m below the earthworks final surface as defined in Clause 7.1.2 for excavation.

8.19.17 Dewatering

(a) Dewatering shall be carried out in such a manner that no loss of fines from the ground occurs.

(b) Silt traps shall be provided and shall be regularly maintained; all dewatering

pumps shall discharge into silt traps. (c) Pumped groundwater shall not be discharged onto roads, footpaths, kerb

channels or adjacent land. The Contractor shall make all arrangements with, and obtain the necessary approvals and consents from the Relevant Authorities and the Project Manager for discharging water to drainage systems, watercourses or the sea. Dewatering shall not start until the permitted arrangements for disposal of the water have been implemented. Water entering the Site shall not be discharged into the same silt traps as are used for dewatering.


(d) The total capacity of pumps available on the Site for dewatering shall be at least equal to twice the rate of flow measured through the silt traps at any time when the groundwater table is maintained at maximum drawdown.

(e) Half of the total pump capacity shall be equipped with a secondary motive

power source in addition to the primary motive power. The secondary motive power source shall commence operation automatically in the event of failure of the primary motive power source or an effective alarm system shall be set up which will warn of failure of the primary motive power source. The maximum allowable delay between failure of the primary motive power source and full operation of the secondary motive power source shall not exceed 15 minutes.

(f) A full-time attendant shall be available on the Site at all times to execute the

changeover if manual operation of equipment is required to bring the secondary motive power into operation.

(g) The operation of the changeover of motive power equipment shall be

demonstrated before the relevant work starts. 8.19.18 Groundwater recharge

(a) If groundwater recharge is to be carried out to maintain the specified groundwater levels at any location, the groundwater recharge system shall have the means to regulate and measure the rate of recharge and to provide an adequate continuous supply of water for recharge. Only clean fresh water shall be used.

(b) The capacity of pumps and the power sources which are to be used for

groundwater recharge shall be as stated in Clause 8.19.17(d) except that the rate of flow shall refer to the maximum rate of groundwater recharge required.

(c) The groundwater table at any location shall not be raised above the

background groundwater table measured before the relevant work starts. 8.19.19 Monitoring of groundwater control and drawdown

(a) Monitoring of groundwater levels shall be carried out at locations stated in the Contract or instructed by the Project Manager at all times when groundwater control and drawdown is carried out. Arrangements for installing instruments and taking measurements both inside and outside the Site shall be made by the Contractor.

(b) The survey marks for monitoring shall be located in position and level to the

Hong Kong standard survey grid and to PD to within 10 mm in every direction. (c) Monitoring stations and monitoring shall be as stated in Clauses 8.21.1 to

8.24.11. (d) Groundwater levels shall be measured to an accuracy of 20 mm. Settlements

shall be measured to an accuracy of 3 mm. (e) The Contractor shall notify the Project Manager immediately if any increment

settlement reading exceeds 5 mm or if the accumulated settlement exceeds the maximum allowable settlement stated in the Contract.


8.20 INSPECTION, TESTING AND COMMISSIONING – GROUNDWATER DRAINAGE AND CONTROL

8.20.1 Records of geotextile filter

Records of installation of geotextile filter shall be kept by the Contractor on Site and a copy shall be submitted to the Project Manager for review each day. Records shall contain the following details:

(a) identification of structures and sections of work where geotextile filter is

installed; (b) type of geotextile filter, including identification of batch; (c) date of first exposure of geotextile filter to ultra-violet radiation before

installation; (d) type of joint, amount of overlap, method of holding in place and any repairs to

geotextile filter carried out during installation; (e) date of installation of geotextile filter; and (f) date of final covering of geotextile filter.

8.20.2 Records of drillholes for raking drains

Records of drillholes for raking drains shall be kept by the Contractor on Site and a drillhole log for each drillhole shall be submitted to the Project Manager for review before installation of the raking drain starts. The borehole log shall contain the following details:

(a) drain reference number; (b) location, inclination, bearings, diameter and length of hole; (c) details of drilling progress; (d) details of water seepage related to drilling progress; and (e) details of samples taken.

8.20.3 Trials for relief drains A trial length of relief drains of at least 2 m shall be constructed.


8.20.4 Records of caisson drains

(a) Records of caisson drains shall be kept by the Contractor on Site and a copy shall be submitted to the Project Manager for review within 14 days after completion of construction of caisson drains. The records shall contain the following details:

(i) record of work carried out each day; and

(ii) drawings showing the exact locations of caisson drains and the final

depths relative to PD.

(b) Detailed face logs of caisson drains shall be kept by the Contractor on Site and shall be available for inspection by the Project Manager at all times. The logs shall contain the information required in Clause 8.5.5(b)(ii), (b)(iii) and (b)(iv) and the format shall be as shown in Figure 10 of 'Geoguide 2: Guide to Site Investigation', Hong Kong Government 1987.

8.20.5 Records of settlement, groundwater control and drawdown

Records of monitoring of settlement, groundwater control and drawdown shall be kept by the Contractor on Site and a copy shall be submitted to the Project Manager for review within 24 hours of taking readings.

8.20.6 Batch: granular filter material

A batch of granular filter material is any quantity of granular filter material of the same type and grading delivered to Site at any one time.

8.20.7 Samples: granular filter material

(a) One sample of granular filter material shall be provided from each 500 m3 or part thereof of the material delivered to Site.

(b) One sample of granular material shall be provided from each 500 m3 or part

thereof of granular filter material which has been deposited and compacted.

(c) The size of each sample taken as stated in Clause 8.20.7(a) shall be 10 kg. The method of sampling shall be in accordance with BS 812:Part 102.

(d) Samples taken as stated in Clause 8.20.7(b), shall consist of material

excavated from the compacted layer to form a flat bottomed, steep sided hole of approximately 0.13 m2 to the complete depth of the compacted layer; a template shall be used to fix the edges of the hole if necessary. The sides and bottom of the hole shall be at least 50 mm from other types of fill material.

8.20.8 Testing: granular filter material

(a) Each sample of granular filter material shall be tested to determine the particle size distribution.

(b) The method of testing shall be in accordance with the wet sieving method

stated in Geospec 3, Test Method 8.1 or 8.2 as appropriate.


8.20.9 Non-compliance: granular filter material

(a) If the result of any test for particle size distribution on a sample of granular filter material taken as stated in Clause 8.20.7(a) does not comply with the specified requirements for particle size distribution, additional samples shall be provided from the same batch and additional tests for particle size distribution shall be carried out.

(b) The batch shall be considered as not complying with the specified

requirements for particle size distribution if the result of any additional test for particle size distribution does not comply with the specified requirements for particle size distribution.

(c) If the result of any test for particle size distribution on a sample of granular

filter material taken as stated in Clause 8.20.7(b) does not comply with the specified requirements for particle size distribution, additional samples shall be provided from the same batch and additional tests for particle size distribution shall be carried out.

(d) The batch shall be considered as not complying with the specified

requirements for particle size distribution if the result of any additional test for particle size distribution does not comply with the specified requirements for particle size distribution.

8.20.10 Batch: fill material for trench drains

A batch of fill material for trench drains is any quantity of fill material for trench drains of the same type delivered to Site at any one time.

8.20.11 Samples: fill material for trench drains

(a) One sample of fill material for trench drains shall be provided from each batch

of fill material for trench drains delivered to Site. (b) The size of each sample and the method of sampling shall be in accordance

with Clause 8.20.7(c). 8.20.12 Testing: fill material for trench drains

(a) Each sample of fill material for trench drains shall be tested to determine the particle size distribution; fill material passing a 425 μm BS test sieve shall also be tested to determine the plasticity index.

(b) The method of testing to determine the particle size distribution shall be in accordance with Geospec 3, Test Method 8.1 or 8.2 as appropriate. The method of testing to determine the plasticity index shall be in accordance with Geospec 3, Test Method 6.1.


8.21 DEFINITIONS AND ABBREVIATIONS - GEOTECHNICAL INSTRUMENTATION 8.21.1 Datum station Datum station is a mark for which horizontal or vertical values, or both, have been

fixed, and which is used as a datum for monitoring or control surveys. 8.21.2 Geotechnical instrumentation

Geotechnical instrumentation is the installation and monitoring of instruments in the ground or structures to provide information on soil and rock parameters, and to monitor specific variations in the condition of the ground or structures for the purposes of geotechnical design, construction control and performance monitoring.

8.21.3 Monitoring mark

Monitoring mark is a mark, fixed or installed, on a structure to be monitored. 8.21.4 Reference point

Reference point is a mark placed close to another important survey mark to aid recovery or replacement.

8.21.5 Survey station

Survey station is a mark on a stone, concrete, metal or wooden block, pipe, peg or other item defining a surveyed position.

8.22 MATERIALS – GEOTECHNICAL INSTRUMENTATION 8.22.1 Instruments for geotechnical instrumentation

(a) Instruments for geotechnical instrumentation and their accessories shall be provided complete with all appropriate tubing, connections, monitoring equipment, read-out units and any other tools necessary for the installation, calibration, setting to work and maintenance of the instruments.

(b) Instruments shall be manufactured by companies with proven experience and

only instruments which are well proven and have been in successful use shall be used.

(c) Instruments shall be handled, stored, installed and used in accordance with

the manufacturer's recommendations and in such a manner that the performance of the instruments will not be impaired.

(d) Instruments shall be protected from damage and measures shall be taken to

ensure that the instruments suffer the minimum practicable amount of disturbance.

(e) Instruments shall be calibrated by a laboratory reviewed without objection by

the Project Manager. Instruments shall be calibrated at intervals recommended by the manufacturer and at other intervals directed by the Project Manager. Calibration certificates shall be provided to the Project Manager for review within 24 hours after calibration.


(f) Installation, testing and monitoring of the instruments shall be carried out

under the supervision of a suitably qualified geotechnical engineer who shall have a minimum of five-years experience of the installation and monitoring of field instrumentation. Particulars of the geotechnical engineer, including qualifications and experience, shall be submitted to the Project Manager for review.

8.22.2 Standpipe piezometers

Standpipe piezometer tips for geotechnical instrumentation shall be porous ceramic or plastic material at least 200 mm long and with a bore of at least 19 mm. Permeability shall be at least 10

-4 m/s. The piezometer tip shall be connected to

rigid PVC standpipes with a bore of at least 19 mm and with a wall thickness of at least 3 mm. The standpipes shall be jointed together and to the porous tips in such a manner that the joints remain leak-proof under the anticipated head of water.

The general layout of the apparatus shall conform to the details shown in Geoguide 2 Figures 19 and 21.

8.23 SUBMISSIONS – GEOTECHNICAL INSTRUMENTATION 8.23.1 Particulars of geotechnical instrumentation

(a) The following particulars of the proposed geotechnical instrumentation shall be submitted to the Project Manager for review:

(i) details of instruments ;

(ii) manufacturer's specifications;

(iii) test and calibration certificates;

(iv) method of installation;

(v) method of acceptance testing;

(vi) details of ancillary measuring equipment;

(vii) schedule for installing instrumentation in relation to progress of the

Works;

(viii) documents showing that the instruments are capable of measuring within the ranges and accuracies stated in the Contract;

(ix) name and experience of persons responsible for installation, testing and

monitoring of instruments;

(x) details of standpipe piezometer tips, including manufacturer's specification; and

(xi) details of the form of records.


8.24 WORKMANSHIP – GEOTECHNICAL INSTRUMENTATION 8.24.1 Location and arrangement of instruments

(a) The locations and arrangement of instruments for geotechnical instrumentation shall be as stated in the Contract or as reviewed without objection by the Project Manager before installation.

(b) The positions and alignments of instruments shall be recorded after

installation and surveys shall be carried out at times and frequencies reviewed without objection by the Project Manager to detect any displacement of the instruments.

(c) At least two reference points shall be established for each survey station or

monitoring mark. (d) The survey station which has the least chance of being disturbed shall be

selected as datum station. The datum station shall be stainless steel. At least three reference points shall be established for each datum station.

(e) The survey network shall be related to the master survey stations provided by

the Project Manager. 8.24.2 Installation of instruments

(a) The Contractor shall notify the Project Manager before the installation of each instrument for geotechnical instrumentation starts.

(b) Tests shall be carried out after installation to demonstrate that the instruments

have been correctly installed and are functioning correctly. Instruments which are not correctly installed or are not functioning correctly shall be reinstalled or replaced as directed by the Project Manager.

(c) All installed instruments, tubes and wires shall be clearly marked with a

unique and conspicuous identification number. 8.24.3 Tubes and cables for instruments

(a) Tubes and cables attached to instruments for geotechnical instrumentation for remote reading shall be impervious to air and water, and shall have sufficient strength and stiffness to withstand the internal and external pressures. Tubes and cables shall be protected from mechanical damage and from the harmful effects of direct sunlight, heat and ultra violet radiation at all times.

(b) Tubes and cables shall be marked with identification colours and numbers at

5 m intervals. The tubes and cables shall be wound onto reels in such a manner that kinks are not formed and strain is not induced. Open ends of tubes and cables shall be blocked with stop ends at all times.

(c) Tubes and cables shall be buried at least 0.5 m below ground level.


(d) Tubes and cables shall be laid with sufficient slack, loops and bends to allow for settlement and other ground movements. The routing of tubes and cables shall be as reviewed without objection by the Project Manager. The radius of bends shall be at least 300 mm. Each tube or cable shall be laid from the measuring instrument to the terminal duct in one continuous length without joints.

8.24.4 Maintenance of instruments

(a) Instruments for geotechnical instrumentation shall be maintained in good working order until the expiry of Defects Liability Period. Instruments, survey marks and stations shall be protected by suitable barricades, notices, signs or marker-buoys.

(b) The Contractor shall notify the Project Manager immediately of any

instruments found damaged or instruments found not to be in working order. Replacements shall be installed for read-out units which are faulty or under repair.

8.24.5 Records of geotechnical instrumentation

(a) Records of activities relating to installation of geotechnical instrumentation shall be kept by the Contractor on Site and a copy shall be submitted to the Project Manager for review within 24 hours after installation of the instrument is complete.

(b) Contractor’s Drawing showing the locations and identification of installed

instruments shall be submitted to the Project Manager for review within 24 hours after installation of the instrument is complete.

(c) Contractor’s Drawing showing the locations and details of survey stations,

monitoring marks and reference points shall be submitted to the Project Manager for review within 3 days after the survey network has been established.

8.24.6 Recording readings

(a) Instrument readings and processed data for geotechnical instrumentation shall be recorded by the Contractor on agreed record sheets, and shall be submitted to the Project Manager for review within 24 hours after recording. The form of record sheets shall be as reviewed without objection by the Project Manager. Readings shall be taken in the presence of the Project Manager.

(b) Initial readings shall be taken immediately after the instruments have been

installed and after the effects of installation have subsided. The initial readings shall be submitted to the Project Manager for record and shall form the basis of comparison of subsequent readings. The instruments and the initial readings shall be replaced if the initial readings are not repeatable.

(c) The frequencies for reading instruments shall be as reviewed without

objection by the Project Manager. The Contractor shall notify the Project Manager immediately of sudden or significant changes in the readings.


(d) All installed instruments shall be left in correctly functioning condition after final readings have been taken or at the end of the Defects Liability Period. Keys for locks shall be tagged to identify the instrument number and shall be handed over to the Project Manager.

8.24.7 Installation of settlement plates

(a) Settlement plates for geotechnical instrumentation shall be securely founded on level ground free from obstructions and shall be immediately surveyed for level and position and plotted on a plan.

(b) Settlement plates shall be protected from damage and shall be kept in

position by a 600 mm thick layer of granular fill material or bags of sand which shall be placed by manual methods and shall extend 600 mm beyond the edges of the plate. The initial survey of levels and positions shall be taken immediately after the fill material or bags of sand have been placed.

(c) The metal rod fixed to the centre of the plate shall be in an upright position,

and protected by a tubular sleeve. The sleeve and the metal rod shall be extended as fill material is placed such that at any time the sleeve and rod are at least 500 mm above the level of the surrounding fill material or high water mark, and the metal rod is within 2% of the embedded length to the vertical.

(d) The level of the top of the metal rod shall be recorded immediately before and

immediately after each extension piece is added. Marker-buoys shall be fixed to the tops of tubular sleeves installed in water.

8.24.8 Installation of tiltmeter system

(a) Tilt-plates for geotechnical instrumentation shall be orientated to correspond with the specified direction of measurement and fixed in place on the rock or structure. The installed direction shall be recorded to an accuracy of ±3°.

(b) A protective cap or cover shall be fitted to protect the tilt-plates from damage. (c) Tilt-plates and the tiltmeter shall be cleaned and inspected for damage before

readings are taken. The tiltmeter shall be accurately located on the tilt-plate and a reading taken. The tiltmeter shall then be removed and the contact surface recleaned. The procedure shall be repeated until consistent readings are obtained. The tiltmeter shall then be rotated through 180° and the procedures repeated.

(d) The accuracy of the tiltmeter and its readout system shall be checked both

before and after the readings taken each day. Instrument errors shall be investigated and immediately corrected; a record of calibrations and adjustments shall be submitted to the Project Manager for review together with the monitoring data.

8.24.9 Installation of telltales

Telltales for geotechnical instrumentation shall be as shown in Figure 10.5 of 'The Geotechnical Manual for Slopes', Hong Kong Government, 1984. Telltales shall be rigidly fixed across cracks to enable any movement across the cracks to be determined. Telltales shall be labeled and marked with the date of installation.


8.24.10 Installation of standpipe piezometers

(a) Standpipe piezometers for geotechnical instrumentation shall be installed in drillholes at the depths as stated in the Contract or as directed by the Project Manager.

(b) The sand filter surrounding the piezometer tip shall be between 1000 mm and

1500 mm long and shall consist of sand between the sizes of 200 μm and 1210 μm. Measurements shall be made to determine the actual location of the sand filter column.

(c) A seal shall be formed above the sand filter by placing 500 mm of bentonite

pellets of between 10 mm and 15 mm in size. The pellets shall be placed in the hole and tamped with a suitably shaped tamper to form a homogeneous plug to the hole.

(d) If the depth of the completed hole is greater than the depth at which the

piezometer tip and sand filter are to be placed, the bottom of the drillhole shall be grouted with grout consisting of cement and bentonite in the proportions 1:1 by mass together with sufficient water to achieve the required workability. The drillhole above the plug shall be grouted with the same type of material.

(e) The water level in the piezometer shall be measured after the standpipe

piezometer has been installed and the standpipe shall be topped up with clean water. The rate of drop of water level or pressure head shall be recorded at times of 0, 1/4, 1/2, 1, 2, 4, 8, 15, 30 minutes or until the water has returned to its initial level.

(f) The water level shall be measured by an electrical type water level probe

reviewed without objection by the Project Manager. The water may be salted if necessary for response to the probe.

(g) Measurements of the depth of piezometer tip and sand filter and the readings

taken as stated in Clause 8.24.10(f) shall be submitted to the Project Manager for review within 24 hours after completion of installation of the piezometer standpipe.

(h) Surface boxes as shown in Geoguide 2 Fig 21 shall be constructed within 2

days of completion of the piezometer installation and backfilling of the hole. (i) The hole reference number shall be permanently inscribed on the surface box

either by welding a numbered steel plate to the box cover or by inscribing the number in the concrete surround.


8.24.11 Observation wells

(a) Where shown on the Employer’s Drawings or as otherwise instructed by the Project Manager, the Contractor shall provide and install an observation well.

(b) The observation well shall consist of rigid PVC tubing to the dimensions and

installation details as described in Clause 8.24.10 except that the tube shall be capped at its lower end and perforated with 6 mm diameter holes for a minimum of 5% of its surface area over a length of 1.5 m or as instructed by the Project Manager. The upper end of the tube shall be set in concrete and fitted with a surface box as shown in Geoguide 2 Figure 21. The perforated length shall be wrapped with two layers of nylon mesh. The granular surround to the perforated length shall be 10 to 16 mm washed aggregate.

(c) The elevation of the base and the top of the granular surround shall be

recorded on the log. The depth to the base of the observation well shall be confirmed by dipping on completion of the installation.

8.25 GENERAL - LABORATORY WORK 8.25.1 General

(a) The Contractor shall, when instructed by the Project Manager, carry out soil tests specified in this Section at a HOKLAS accredited laboratory reviewed without objection by the Project Manager.

(b) The laboratory shall hold current HOKLAS accreditation for tests according to

Geospec 3. (c) The “Laboratory Work” shall be completed within four weeks of the completion

of the “Field Works”.

8.25.2 Work on General Holidays

No testing shall be carried out on general holidays without permission in writing by the Project Manager.

8.25.3 Contractor’s supervision

Laboratory testing shall be carried out under the continuous supervision of a competent engineer or senior technician who is experienced in soils testing procedures. This person shall certify the accuracy, correctness and completeness of the test results supplied to the Project Manager by the Contractor.

8.25.4 Staff - definitions

For laboratory testing the following definitions shall apply:- Senior technician - a person with at least 10 years experience gained in a soil testing laboratory and fully familiar with triaxial testing procedures.


8.25.5 Results, samples and original sample containers property of the Employer

The results of the tests shall become the property of the Employer and shall not be divulged by the Contractor except to the Employer or the Project Manager. Samples and the original sample containers are the property of the Employer and the Contractor shall not dispose of any samples, original sample containers or parts thereof except as directed by the Project Manager.

8.26 WORKMANSHIP – LABORATORY WORK 8.26.1 Extrusion of ‘Mazier’ samples for testing

For testing purposes, 'Mazier' samples shall be cut to the appropriate length for testing and then extruded in the direction of the top of the sample in a manner reviewed by the Project Manager.

8.26.2 Retention of samples

When laboratory tests are carried out on only part of a soil sample, the remainder of the soil in the sampler or container shall be resealed with wax as soon as possible and retained. Soil on which laboratory tests have been carried out, including that wasted during the preparation of test specimens, shall be retained in airtight containers until the presentation of the “Final Report”.

8.26.3 Classification and chemical test procedures

The following laboratory soil classification tests shall where applicable be carried out in accordance with the procedures described in Geospec 3 :-

(a) determination of moisture content (Test Method 5.1 or 5.2 as appropriate); (b) determination of liquid limit (Test Method 6.1). The sample shall not be

completely dried before testing; (c) determination of plastic limit, plasticity index and liquidity index (Test Method

6.1 and 6.2). The soil shall not be completely dried before testing; (d) determination of particle density for soils containing gravel sized particles

(Test Method 7.1). Samples at natural moisture content of dry weight approximately equal to that specified in BS 1377 shall be used. The sample shall not be dried prior to testing but shall be oven dried and weighed on completion of the test. The test shall be carried out using distilled water; and

(e) determination of particle size distribution on:

(i) essentially cohesionless soil down to the fine sand size (Test Method

8.1 or 8.2 as appropriate); and

(ii) coarse sand to clay size (Test Method 8.3, 8.4, 8.5 or 8.6 as appropriate).


8.26.4 Triaxial test procedures “Triaxial Test Procedures” as specified in Clauses 8.26.5, 8.26.21 and 8.26.22 shall be based upon "The Measurement of Soil Properties in the Triaxial Test" (Second edition, 1962) by A.W. Bishop and D.J. Henkel, unless otherwise instructed by the Project Manager.

8.26.5 Use of ceramics

When necessary, as determined by the Project Manager, high air-entry ceramics shall be used to separate the soil specimen from the base drain (Bishop and Henkel p. 221). For any test where pore pressure is measured from the top of the specimen, it shall be permissible to use low air-entry ceramics for separating the specimen from the top cap. Porous ceramics shall be de-aired (Bishop and Henkel p. 185).

8.26.6 Calibration of pressure gauges

Equipment capable of providing and maintaining steady cell pressures of up to 850 kPa shall be used. Pressure gauges (i.e. those used for cell pressure, pore pressure and back pressure measurements) shall be calibrated against an accurate dead load tester or alternative method agreed by the Project Manager unless calibrated within the three months preceding the start of any test. The Contractor shall provide the Project Manager with calibration charts showing the corresponding values of the dead weight tester(s) and the pressure gauges. Results shall be presented in increments of 50 kPa up to and including 850kPa. Calculations shall be based on the pressure gauge readings reduced to their calibrated values.

8.26.7 De-aired water De-aired water shall be used to saturate soil specimens and for cell water. Adequate provision shall be made at any air/water interfaces in the pressure application system to minimise air contamination of the water.

8.26.8 Specimen diameter

The size of specimen to be tested shall normally be 76 mm in diameter. Test specimens shall be prepared from undisturbed samples (Bishop and Henkel p. 83), or disturbed samples compacted or remoulded at a specified moisture content to a specified density (Bishop and Henkel p. 87) in a manner reviewed by the Project Manager.

8.26.9 Jacketing gritty soils

In the case of gritty soils two membranes shall be used for jacketing the soil specimen, unless agreed otherwise with the Project Manager. Membranes shall be checked for leakage before use.


8.26.10 Saturation of specimens by back-pressure

Test specimens shall be saturated by the application of back-pressure before the consolidation stage. The saturation procedure shall be as follows:-

(a) application of an undrained 50 kPa increment in cell pressure (σ3). Adequate

time shall be allowed for pore-water pressure response (Δu) to stabilise. If the ratio Δu/ σ3 (hereafter called B) is less than 0.97 or as decided by the Project Manager, then

(b) the back-pressure shall be brought up to the value of the cell pressure minus

5 kPa with the drain closed. The drain shall then be opened and the volume change shall be noted and adequate time shall be allowed for this change to cease. Procedure (1) shall then be repeated.

If B exceeds 0.97, then

(c) the cell pressure shall be taken up in undrained increments of 50 kPa or less

to the value of the test cell pressure allowing pore water stabilization at each increment, and the pore water pressure shall be recorded immediately after application of each additional increment of pressure.

8.26.11 Saturation by flooding

When instructed by the Project Manager samples shall be saturated by flooding. The procedure for single-stage and for the first stage of multi-stage testing shall be as follows:- (a) if saturation by back-pressure has been attempted, the cell pressure shall be

reduced to 50 kPa and simultaneously the back-pressure shall be reduced to 40 kPa. If saturation by back-pressure has not been attempted, cell pressure shall be set at 50 kPa and back-pressure at 40 kPa; and

(b) maintaining these pressures, the drain shall be opened from the sample top

cap to the atmosphere and de-aired water shall be allowed to flow through the sample until bubbling ceases. The drain shall then be closed and the sample saturated by back-pressure as specified in sub-clause (a) above.

8.26.12 Corrections to be applied to the value of deviator stress

The following corrections, where appropriate, shall be applied when calculating the deviator stress and shall be indicated in the results:-

(a) change in cross-sectional area (Bishop and Henkel, p. 28); (b) restraint from the rubber membrane and filter paper drains (Bishop and

Henkel, p. 167); and (c) friction on the loading ram (Bishop and Henkel, p. 174).


8.26.13 Definition of shear failure

Shear failure for single stage triaxial tests shall be defined in terms of maximum principal stress difference (σ1 - σ3). Shear failure for multi-stage triaxial tests shall normally be defined in terms of maximum principal effective stress ratio (σ 1'/ σ3') unless otherwise instructed by the Project Manager.

8.26.14 Shear plane failure

For specimens which fail along a shear plane, the axial strain at which the shear plane becomes apparent shall be recorded.

8.26.15 Required sketches of specimen failure

A sketch shall be made of the mode of specimen failure. The angle of any distinct shear planes shall be measured with respect to the horizontal and noted both before splitting and after splitting the specimen.

8.26.16 Consolidated-undrained single-stage triaxial tests (a) “Consolidated-undrained Single-Stage Triaxial Tests” (Bishop and Henkel

(1962) pp. 106 and 192) shall be carried out with pore-water pressure measurement and using back-pressure for saturating the sample. At the end of the consolidation stage a suitable rate of axial strain shall be agreed with the Project Manager to ensure that the results obtained shall lead to a true measure of the physical properties of the soil. The rate shall be sufficiently low to ensure equalisation of pore-water pressure throughout the specimen and shall not exceed 0.2 mm/min.

(b) The report of each test shall include the following information:-

(i) sample and specimen number;

(ii) location and depth of the sample;

(iii) description of the test specimen;

(iv) method of preparation and dimensions of the specimen;

(v) initial and final moisture content, volume and bulk density and specified effective cell pressure;

(vi) pore-pressure parameter B for each increment of back-pressure;

(vii) maximum pore-pressure parameter Bmax (being the maximum B value

calculated for the 50 kPa increments in cell pressure);

(viii) final back-pressure;

(ix) standard increment of cell pressure (50 kPa, unless otherwise specified by the Project Manager); and

(x) final value of pore-water pressure generated by the final undrained

increment in cell pressure;


Consolidation:

(xi) volume change/square-root of time plot; and

(xii) computed coefficient of consolidation, coefficient of permeability and coefficient of volume compressibility;

Shearing Stage:

(xiii) rate of axial strain;

(xiv) deviator stress/axial strain plot;

(xv) principal effective stress ratio/axial strain plot;

(xvi) pore water pressure/axial strain plot;

(xvii) maximum deviator stress and corresponding axial strain;

(xviii) maximum principal effective stress ratio and corresponding axial strain;

8.26.17 Consolidated-undrained multi-stage triaxial tests

“Consolidated-Undrained Multi-Stage Triaxial Tests” shall be carried out in 3 stages with pore-water pressure measurement in accordance with procedures defined in the Clause 8.26.16 relating to single-stage tests except that:-

(a) B values recorded during saturation by back-pressure shall be determined as

described in Clauses 8.26.10 or 8.26.11 and in addition by measuring the Δu/σ3 ratio as the cell pressure is increased between stages.

(b) If failure has not occurred in a particular stage, shearing for that stage shall be

stopped at the following cumulative strains, subject to the Project Manager’s agreement:

(i) initial loading 15%;

(ii) second loading 20%; and

(iii) third loading 25%.

8.26.18 Consolidated-drained single-stage triaxial tests

(a) “Consolidated-Drained Single-Stage Triaxial Tests” (Bishop and Henkel, pp. 124 and 204) shall be carried out as directed by the Project Manager. At the end of the consolidation stage the Contractor shall calculate a suitable rate of axial strain acceptable to the Project Manager. This rate shall be sufficiently low as to ensure at least 95 per cent dissipation of excess pore-pressure at failure.

(b) The report of each test shall include the requirements listed in

Clause 8.26.16(b) together with a volume change/axial strain plot.


8.26.19 Unconsolidated-undrained triaxial tests

(a) “Unconsolidated-Undrained Single-Stage Triaxial Tests” without the measurement of pore-water pressure shall be carried out using back-pressure for saturating the sample.

The tests shall be carried out in accordance with Part 7 Method 8 of BS 1377. (b) The report of each test shall include the following information:

(i) sample and specimen number;

(ii) location and depth of the sample;

(iii) description of the test specimen;

(iv) method of preparation and dimensions of the specimen;

(v) initial and final moisture content, volume and dry/bulk density;

(vi) specified effective cell pressure;

(vii) pore-pressure parameter B for each increment of back-pressure;

(viii) maximum pore-pressure parameter Bmax (being the maximum B value calculated for the 50 kPa increments in cell pressure);

(ix) final back-pressure;

(x) standard increment of cell pressure (50 kPa, unless otherwise specified

by the Project Manager); and

(xi) final value of pore-water pressure generated by the final undrained increment in cell pressure; and

(xii) Shearing Stage:

(xiii) rate of axial strain;

(xiv) deviator stress/axial strain plot; and

(xv) maximum deviator stress and corresponding axial strain.

8.26.20 Plotting of results

A Mohr stress circle diagram shall be prepared for results of a series of tests on the same sample or for results of one multi-stage test providing plastic failure has occurred in each specimen or planar failure has been on planes included at approximately (45 degrees +0/ '/2) to the horizontal. The apparent cohesion (c') and angle of shearing resistance (0/ ') with respect to changes in effective stress shall be determined by the "least-squares" fitting technique. For failure of specimens on planes not inclined at an angle of approximately (45 degrees +0/ '/2) to the horizontal, the Project Manager shall decide on the mode of presentation of the results.


8.26.21 Photographing of triaxial test specimens

(a) A colour photographic record shall be kept of triaxial test specimens after testing. The Contractor shall take all photographs required by the Project Manager.

(b) A reference label, scale and colour chart from the manufacturer applicable to

the type of film and paper used shall be placed together with the specimen in the camera's field of view and a photograph shall be taken at a magnification agreed with the Project Manager.

(c) The photographs shall be processed so as to ensure accurate reproduction of

colours, as shown by the colour chart. One print of each photograph, and a copy of the colour chart, shall be attached to each copy of the “Draft Final Report” and to each copy of the “Final Report”. The set of negatives shall be attached to the master copy of the “Final Report”.

8.26.22 Drained modulus tests

(a) “Drained Modulus Tests” shall be carried out in a triaxial testing machine. The test specimens shall be prepared, saturated and consolidated prior to the application of axial strain in accordance with procedures relating to “Consolidated-Drained Single Stage Triaxial Tests” (Clause 8.26.18). The specimen shall then be loaded to a deviator stress as instructed by the Project Manager before being unloaded. The rate of application of axial strain during loading/unloading shall be sufficiently low to ensure at least 95 per cent dissipation of excess pore-pressure. The above loading/unloading procedures shall be repeated for four other cycles to different deviator stresses instructed by the Project Manager.

(b) The report of each test shall include the requirements given in Clause

8.26.16(b) except that items (xiii) to (xviii) shall be replaced by:

Loading/Unloading Stage:

(i) rate of axial strain;

(ii) deviator stress/axial strain plot;

(iii) volume change/axial strain plot; and

(iv) pore-water pressure/axial strain plot. 8.26.23 Consolidated-drained shear box tests on soil

(a) Consolidated-drained single-stage and multi-stage direct shear box tests shall be carried out on samples of soil containing relict joints or discontinuities in accordance with the requirements specified in this Clause. The Contractor shall submit to the Project Manager for review:

(i) the proposed testing equipment; and

(ii) the proposed method of specimen preparation.


(b) Samples shall be handled with great care at all times. The jointed specimens shall be prepared in such a way that shearing occurs along a continuous joint surface.

(c) After applying the initial normal pressure (30 kPa), water shall be added to the

carriage to a level such that the specimen is completely immersed. Then the normal pressure shall be increased to the required value for shearing and maintained for a minimum period of 12 hours for consolidation. Any settlement of swelling taking place during the process shall be measured by dial gauge at suitable time intervals. The specimen shall be maintained in a soaked condition throughout the test.

(d) The rate of testing shall be not greater than 0.1 mm/min, and the suitability of

the rate shall be checked from consolidation stage data. Shearing shall be continued for the full travel of the shear box.

(e) Colour photographs shall be taken of all specimens before and after testing.

A reference label, scale and colour chart from the manufacturer applicable to the type of film and paper used shall be placed together with the specimen in the camera's field of view and a photograph shall be taken at a magnification agreed with the Project Manager. The photographs shall be processed so as to ensure accurate reproduction of colours, as shown by the colour chart. One print of each photograph, and a copy of the colour chart, shall be attached to each copy of the “Draft Final Report” and to each copy of the “Final Report”. The set of negatives shall be attached to the master copy of the “Final Report”.

(f) Testing shall otherwise be carried out in accordance with the procedure given

in "Laboratory Testing in Soil Engineering" by T.N.W. Akroyd. (g) Preparation of specimens for testing shall be carried out in the presence of an

experienced geotechnical engineer. (h) The report on each test shall include the following information:-

(i) sample no.;

(ii) description of the test specimen including sketches, with special attention to features such as tightness, nature of joint surface, nature of infilling material, waviness, asperities etc.;

(iii) initial and final moisture content and bulk density;

(iv) shear force/horizontal displacement plot;

(v) shear force/vertical displacement plot;

(vi) maximum shear force for each shear stage;

(vii) horizontal displacement corresponding to maximum shear force; and

(viii) when instructed by the Project Manager, a shear force/effective normal

load diagram shall be prepared corresponding to maximum shear force determined on a number of test specimens or stages from one sample, and the cohesion (c') and angle of shearing resistance (0/ ') with respect to effective stresses shall be determined.


8.26.24 Permeability tests

Falling head permeability tests (Akroyd p. 147) and constant head permeability tests (Akroyd p. 154) shall be carried out on specimens of up to 110 mm in length and diameter. The report of each test shall include the following information:-

(a) sample no.; (b) location and depth of the sample; (c) description of the test specimen; (d) method of preparation of the specimen; (e) moisture content and bulk density; and (f) coefficient of permeability.

8.26.25 California bearing ratio tests

(a) “California Bearing Ratio” (CBR) Tests shall be carried out in accordance with the procedures described in BS 1377 Part 4 Method 7. The test shall be carried out on each sample over a range of moisture contents so that the relationship of CBR to moisture content can be determined. The test shall include at least 5 determinations with moisture contents chosen from the results of the “Soil Compaction Test” and including optimum moisture content and the values of moisture content corresponding to a dry density of 95 per cent of the maximum.

(b) The results shall be recorded on forms similar to Forms 4E to 4G, BS 1377

and acceptable to the Project Manager. 8.26.26 Soil compaction tests

(a) Soil Compaction Tests shall be carried out in accordance with the procedures described in BS 1377 Part 4 Method 3.3 or 3.4 as appropriate (2.5 Kg rammer)(at least 5 determinations per test are required).

(b) In the case of density determinations carried out at moisture contents less

than the natural moisture content in a compaction test, the soil shall not be allowed to dry to a moisture content lower than the moisture content at which the density determination is to be made.

(c) The results shall be recorded on a form similar to Form 4A, BS 1377 and

acceptable to the Project Manager. 8.26.27 One dimensional consolidation tests

“One Dimensional Consolidation Tests” shall be carried out in accordance with the procedures described in BS 1377 Part 5 Method 3. The results shall be recorded on a form similar to Forms 5A to 5D, BS 1377 and acceptable to the Project Manager.

8.26.28 Rock Compression Tests Uniaxial rock compression tests shall be conducted according to ASTM D2938-86. Test results shall be presented according to relevant ASTM Standard, or according to an alternative reviewed without objection by the Project Manager.


8.26.29 Elastic Moduli and Poisson’s Ratio of Intact Rock Elastic moduli of intact rock core specimens shall be determined according to ASTM D3148-86. Test results shall be presented according to the relevant ASTM Standard, or according to an alternative reviewed without objection by the Project Manager. A plot of compressive stress versus axial diametral strain shall also be presented.

8.26.30 Point Load Tests (a) Point load tests shall be conducted and reported according to the “Suggested

Method of Determining Point Load Strength” by ISRM (1985). Test results shall be presented according to relevant ISRM figures, or according to an alternative reviewed without objection by the Project Manager.

(b) When testing core samples, each test specimen shall first be tested with the

direction of loading perpendicular to the axis of the core (i.e. the diametral test), and secondly with the direction of loading either along the axis of the core or perpendicular to observable planes of anisotropy (i.e. the axial test). When testing irregular specimens that show anisotropy, one-half of the test specimens shall be tested with the load perpendicular to the planes of anisotropy, and the remaining half of the test specimens shall be tested with the load parallel to the planes of anisotropy.

8.26.31 Rock Joint Shear Tests

Rock joint shear tests shall be conducted according to “Suggested Methods for Determining Shear Strength” by ISRM (1974), as modified by the following: (a) rock joint shear tests shall be conducted using either a Golder or Roberston

Shear Box. The choice of shear box shall be as directed by the Project Manager;

(b) except as otherwise instructed, multi-stage tests shall be used;

(c) the following items shall be included for rock joint shear tests, with test results

presented according to relevant ISRM figures, or according to alternatives reviewed without objection by the Project Manager:

(i) the dimensions of the top and bottom shear surfaces shall be

determined and recorded;

(ii) the actual area of contact between the top and bottom shear surfaces shall be estimated: areas that have regular shapes shall be calculated: areas that have irregular shapes shall be estimated using graph paper;

(iii) the roughness profile shall be recorded, before and after shear, with the

aid of a profilometer. A description of the rock joint shall also be made, including colour, tightness and nature of joint infill materials, if any;

(iv) photographs of top and bottom joint surfaces, before and after shear,

shall be taken according to Clause 8.26.21;


(v) the horizontal displacements, vertical displacements, shear loads and normal loads shall be recorded during the tests; and

(vi) the specimen shall be soaked in water overnight before testing, unless

otherwise instructed by the Project Manager.

(d) the following corrections shall be made when calculating stresses:

(i) hydraulic ram springs: when hydraulic ram springs have been used a correction shall be applied to gauge readings to account for the resistance provided by the ram return springs;

(ii) cross-sectional area: the reduction in cross-sectional area during the

shearing process shall be accounted for; and

(iii) contributions to normal load, such as the self-weight of the loading system and the weight of the upper box and sample shall be accounted for.

(e) the following plots shall be prepared according to the relevant ISRM, or

according to an alternative reviewed without objection by the Project Manager:

(i) shear stresses versus horizontal displacement;

(ii) shear stresses and vertical displacement shall use the same abscissa that represents the horizontal displacement; and

(iii) peak shear stresses versus normal stress, uncorrected and corrected for dilation; and

(f) the variations to the above procedure for testing tight joints shall be as reviewed without objection by the Project Manager.

8.26.32 Velocity of Sound in Rock

The determination of the velocity of sound in rock shall be made according to “Suggested Methods of Determining Sound Velocity” Method 1 or 2 (for P-wave and S-wave), by ISRM in “Rock Characterisation Testing and Monitoring” by E.T. Brown (editor) (1981).

8.26.33 Porosity and Dry Density of Rock The determination of porosity and dry density of rock shall be made according to “Suggested Method for Porosity/Density Determination Using Saturation and Calliper Techniques” Method 2, or “Suggested Method for Porosity/Density Determination Using Saturation and Buoyancy Techniques” Method 3, by ISRM in “Rock Characterisation Testing and Monitoring” by E.T. Brown (editor)(1981).


8.27 INSPECTION, TESTING AND COMMISSIOINING – LABORATORY WORK 8.27.1 Presentation of test results

(a) The test results shall be presented in tabular and/or graphical form as appropriate and on forms acceptable to the Project Manager. Examples of suitable forms for presentation are given in BS 1377 and also in Manual of Soil Laboratory Testing by K H Head Published by Pentech Press Limited, Graham Lodge, Graham Road, London NW4 3DG, England.

(b) Four preliminary copies of the results of each test complete with test data and

photographs shall be submitted to the Project Manager within two days of completion of the test. The records shall be legible and intelligible and shall be stamped PRELIMINARY.

8.27.2 Progress reports

Whilst laboratory testing is in progress, the Contractor shall inform the Project Manager without delay of any unusual or irregular occurrences observed during any of the laboratory tests ordered.

8.27.3 Draft final report

Within three days of completion of the “Laboratory Work” the Contractor shall submit three copies of the “Draft Final Report”. The contents and standard of presentation shall be as proposed for the “Final Report”. The presentation shall be neat, clear and intelligible. Each page, and the cover, shall be stamped “DRAFT”. The Project Manager will return one copy of the “Draft Report” to the Contractor with his comments within three weeks of receipt of the report.

8.27.4 Final report

(a) The “Final Report” shall contain the information described in the following sub-clauses relevant to the Works. In preparing the “Final Report”, account shall be taken of comments made by the Project Manager after examining the “Draft Final Report”.

The information on the cover page shall include:

(i) names of Employer, Contractor, Project Manager;

(ii) title and number of Contract; and

(iii) date of report (month and year).

The introductory text shall include:

(iv) description of Site location;

(v) dates of investigation;

(vi) methods used in making holes, taking samples and carrying out in-situ

tests;


(vii) methods used in carrying out laboratory tests;

(viii) details of any bench marks and/or survey beacons to which the “Field Work” is referenced; and

(ix) any other relevant information.

(b) The location of holes and tests shall be shown on a plan or plans of the Site. (c) Final logs and any photographs specified shall be appended. The master

copy of each final log together with the negatives of all photographs specified shall be included with the master of the “Final Report”. Logs shall be ring bound to facilitate photocopying.

(d) The results of in-situ tests shall be presented on the logs of holes and/or in

tabular and/or graphical form, as appropriate. The information given shall include that provided for by the relevant test procedure in accordance with Clause 8.6.1 together with other information necessary for a full understanding of the results.

(e) The results of laboratory tests on earthworks materials shall be presented in

accordance with Section 7. The information given shall include that provided for by the relevant test procedure and any other information necessary for a full understanding of the results.

(f) Page size shall be A4. (Tables and figures shall be A4 height but greater

width, folded in such a way that the essential titles can be read without opening).

(g) One master and ten bound copies of the “Final Report” shall be submitted. (h) The “Final Report” shall be submitted within 2 weeks of the return to the

Contractor of the “Draft Report” with the Project Manager’s comments.


APPENDIX A8.1

"GEO" PROBE TEST A8.1.1 Scope This method covers the determination of the penetration resistance of soil using the

GEO probe. A8.1.2 Apparatus The following apparatus is required: (1) GEO Probe as shown in Figure 36 of 'Geoguide 2 : Guide to Site

Investigation,' Hong Kong Government 1987. The anvils shall be rigidly fixed to the guide rod, the lower anvil shall also be rigidly fixed to the extension rods. The mass of the lower anvil shall be between 1.5 kg and 1.8 kg. The combined mass of the lower anvil, guide rod and upper anvil shall not exceed 5.0 kg.

(2) Extension rods with a length of 1000 mm ±10 mm. The rods shall be attached

to bear against each other by means of external couplers. A8.1.3 Procedure The procedure shall be as follows: (1) The lower end of the probe shall be rested against the ground at the test

location, with the first extension rod and guide rod in a vertical position. (2) The hammer shall be raised to bear against the upper anvil, and shall be

allowed to fall freely. It shall not be connected to objects which may influence its acceleration and deceleration, and shall be stationary when released in the upper position. The fall shall be 300 mm ± 5 mm.

(3) The hammer shall be used to drive the probe into the ground, with a rate of

driving between 20 and 60 blows per minute. (4) Additional extension rods shall be added as necessary. The rods shall be

rotated clockwise one full turn each time a rod is added to ensure that screw joints are tight.

(5) The blow count for every 100 mm of penetration shall be recorded, or at

refusal the penetration distance for 50 blows of the hammer. Interruptions exceeding 5 minutes shall be recorded.


The following shall be reported: (1) Blow count for every 100 mm penetration or at refusal the penetration

distance for 50 blows of the hammer. (2) Interruptions exceeding 5 minutes.


(3) GEO probe record as shown in Figure 37 of 'Geoguide 2 : Guide to Site Investigation,' Hong Kong Government 1987.

(4) That the test was carried out in accordance with this General Materials and



APPENDIX A8.2

DETERMINATION OF THE FLOW OF GROUT

A8.2.1 Scope This method covers the determination of the flow of grout by measuring the time of

efflux of a specified volume of grout from a standard flow cone. A8.2.2 Apparatus The following apparatus is required :- (1) A flow cone reviewed without objection by the Project Manager (2) A stop watch with a least reading of not more than 0.2s. (3) A thermometer. A8.2.3 Procedure : Calibration The procedure for calibrating the flow cone shall be as follows :- (1) The flow cone shall be firmly mounted in such a manner that the top will be

level and the cone will be free from vibration. (2) The discharge tube shall be closed by placing the finger over the lower end.

A quantity of 1725 mL ± 1 mL of water shall be introduced to the cone. (3) The point gauge shall be adjusted to show the level of the water surface. A8.2.4 Procedure : Flow Test The procedure for determination of the flow of the grout shall be as follows : (1) Two specimens of grout shall be taken from the sample of grout. The size of

each specimen shall be 1725 mL ± 1 mL. (2) The inside surface of the flow cone shall be wetted by filling the cone with

water and allowing the water to drain from the cone 1 minute before the specimen of grout is introduced to the cone.

(3) The temperature of the grout shall be recorded. (4) The discharge tube shall be closed by placing the finger over the lower end.

The specimen shall be introduced to the cone until the surface of the grout is in contact with the point gauge.

(5) The stop watch shall be started and the finger removed from the discharge

tube simultaneously.


(6) The stop watch shall be stopped at the first break in the continuous flow of grout from the discharge tube. The time shall be recorded to the nearest 0.2s as the time of efflux.

(7) The cone shall be thoroughly cleaned and the procedure stated in Clauses

A8.2.3 and A8.2.4 (1) to (6) shall be repeated for the second specimen. A8.2.5 Calculation The average time of efflux of the 2 specimens shall be calculated. A8.2.6 Reporting of Results The following shall be reported : (1) The times of efflux of each specimen to the nearest 0.2s. (2) The average time of efflux to the nearest 0.2s. (3) The temperature of the specimens. (4) The ambient temperature. (5) Composition of the sample.

(6) Description of physical characteristics of the sample. (7) That the test was carried out in accordance with this General Materials and


General Materials & Workmanship Specification 1/25 January 2011 Issue No. 5, Volume 1 – Civil & Structural Works Section 9 – Carriageways: Sub-base Material & Bituminous Materials

SECTION 9 CARRIAGEWAYS: SUB-BASE MATERIAL AND BITUMINOUS MATERIALS 9.1 DEFINITIONS AND ABBREVIATIONS 9.1.1 Nominal maximum aggregate size

Nominal maximum aggregate size is the smallest BS sieve size for which the upper limit of the percentage of the aggregate by mass passing is 100%.

9.2 DESIGN AND PERFORMANCE CRITERIA 9.2.1 Design procedure for sub-base material and bituminous materials

(a) Sub-base material and bituminous roadbase materials shall be recipe mixes. Laboratory design mixes other than those for sub-base material and bituminous roadbase materials shall be made and tested as part of the design procedure at a laboratory reviewed without objection by the Project Manager.

(b) Mix designs and associated tests shall be carried out by the Contractor in the

presence of the Project Manager. The Contractor shall notify the Project Manager at least 7 days before carrying out the mix designs.

9.2.2 Design of bituminous materials

(a) Bituminous materials shall consist of coarse and fine aggregates complying with Clause 9.3.2, filler complying with Clause 9.3.3 and bitumen complying with Clause 9.3.4. The different types of bituminous materials shall have particle size distribution and bitumen content within the limits stated in Table 9.4.

(b) The properties of the different types of bituminous materials shall be as stated

in Table 9.1. (c) Bituminous materials of all aggregate sizes, other than bituminous roadbase

material, shall be designed in accordance with the “Marshall Method of Mix Design” stated in The Asphalt Institute Handbook 'MS-2 Mix Design Methods for Asphalt Concrete and other Hot-mix Types,' 1984. The compaction standard shall be 75 blows per side.

(d) Design procedures for bituminous friction course material shall be as stated in

Clause 9.2.2(c) except that the mixing and compaction temperatures shall be consistent with bitumen viscosities of 900 ± 100 centistokes and 2000 ± 200 centistokes respectively.


Table 9.1: Properties of Designed Bituminous Materials

Properties

Type of bituminous material Base course Wearing course Friction course

Nominal maximum aggregate size (mm) 37.5 28 20 10 10

Minimum Marshall Stability (kN)

10.0 10.0 -

Maximum flow value (mm)

4.0 4.0 -

Minimum voids in mineral aggregate as a percentage of total bulk volume

12.5 13.0 14.0 16.0 25.0

Air voids in mix as a percentage of total bulk volume

3.0 - 5.0 3.0 - 5.0 18.0 - 25.0

9.3 MATERIALS 9.3.1 Sub-base material

Sub-base material shall be crushed rock and shall have the properties stated in Table 9.2. Sub-base material passing the 425 μm BS test sieve, when tested in accordance with Clause 9.6.10(c) shall be non-plastic.

Table 9.2: Properties of Sub-base Material

Properties BS test sieve Percentage by mass passing

Particle size distribution 75 mm 100 37.5 mm 85 - 100 20 mm 60 - 85 10 mm 40 - 70 5 mm 25 - 45 600 μm 8 - 22 75 μm 0 - 10

Ten percent fines value > 50 kN 9.3.2 Aggregates for bituminous materials

(a) Coarse aggregate for bituminous materials shall be crushed rock all retained on a 5 mm BS test sieve and shall have the properties stated in Table 9.3.

(b) Fine aggregate for bituminous materials shall be crushed rock, river sand or a

mixture of crushed rock and river sand all passing 5 mm BS test sieve. The water absorption of fine aggregate shall not exceed 2.0%.


(c) For the purpose of mix design, the combined grading of aggregates for bituminous materials shall be such that the particle size distribution lies within the limits stated in Table 9.4 for the relevant bituminous material.

Table 9.3: Properties of Coarse Aggregate for Bituminous Materials

Nominal maximum aggregate size (mm)

Properties

37.5 28 20 10

Flakiness index

≤ 25.0% ≤ 26.0% ≤ 27.0% ≤ 30.0%

Ten percent fines value > 100 kN Water absorption ≤ 2.0%

Table 9.4: Design Limits for Particle Size Distribution and Bitumen Content for Bituminous Materials

Properties

Type of bituminous material Roadbase

(recipe mix)

Base course Wearing course

Friction course

Nominal maximum aggregate size (mm)

37.5 37.5 28 20 10 10

Particle size distribution

BS test sieve Percentage by mass passing

50mm 100 100 - - - - 37.5mm 90-100 91-100 100 - - - 28mm 70 - 94 70 - 94 91-100 100 - - 20mm 62 - 84 62 - 84 85 - 95 91-100 - - 14mm - 55 - 76 72 - 87 78 - 90 100 100 10mm 49 - 67 49 - 67 55 - 75 68 - 84 87-100 85-100 5mm 37 - 55 37 - 55 35 - 53 54 - 72 62 - 80 20 - 40 2.36mm 27 - 43 27 - 43 25 - 40 42 - 58 42 - 58 5 - 15 1.18mm - 20 - 35 15 - 30 34 - 48 34 - 48 - 600μm 13 - 28 13 - 28 12 - 24 24 - 38 24 - 38 - 300μm 7 - 21 7 - 21 8 - 18 16 - 28 16 - 28 - 150μm - 4 - 14 5 - 12 8 - 18 8 - 18 - 75μm 2 - 8 2 - 8 3 - 6 4 - 8 4 - 8 2 - 6

Bitumen content as percentage of total mass including binder

min. 3.0 4.0 4.5 5.0 6.0 4.5 max. 4.0 4.5 5.0 5.5 7.0 5.5


9.3.3 Filler for bituminous materials

(a) Filler for bituminous materials shall be crushed rock filler, OPC, PPFAC, PFA or hydrated lime. Filler shall be free-flowing and dry before addition to the bituminous mixture.

(b) Filler for bituminous friction course material shall contain hydrated lime; the

amount of hydrated lime, expressed as a percentage by mass of the total aggregates, shall be at least 1.5%.

(c) OPC shall comply with BS 12. PPFAC shall comply with BS 6588. (d) PFA shall comply with BS 3892 : Part 1 except that the criterion for maximum

water requirement shall not apply. (e) Crushed rock filler and hydrated lime shall comply with ASTM D 242.

9.3.4 Bitumen

Bitumen for bituminous materials shall comply with ASTM D 946, Grade 60-70 and shall have a softening point exceeding 44°C and less than 55°C. Blending or mixing of bitumen shall be carried out at a refinery reviewed without objection by the Project Manager.

9.3.5 Bituminous emulsion

Bituminous emulsion shall be anionic bituminous emulsion complying with BS 434 : Part 1, Table 1, Class A1-40 or cationic bituminous emulsion complying with BS 434 : Part 1, Table 2, Class K1-40.

9.3.6 Bituminous priming material

Bituminous priming material shall be medium curing-grade cutback bitumen complying with ASTM D 2027, Table 1, Class MC-30.

9.3.7 Handling and storage of sub-base material and bituminous materials

(a) Cement and PFA shall be stored as stated in Clause 20.33. (b) Sub-base material and bituminous materials shall not be handled or stored in a

manner which will result in mixing of the different types and sizes or in segregation or contamination of the materials.

(c) Bituminous materials shall not be stored in heated surge bins for more than 12

hours or in transport vehicles for more than 3 hours. (d) Bituminous friction course material shall not be stored in surge bins for more

than 30 minutes.


9.3.8 Transport of sub-base material and bituminous materials

(a) Sub-base material and bituminous materials shall be protected by covers while being transported and before laying. Covers for bituminous materials shall be heavy canvas or a similar insulating material; the covers shall completely cover the material and shall be securely fixed to minimise loss of heat and to protect the materials from contamination by dust or other deleterious material.

(b) Sub-base material and bituminous materials shall be transported in clean

vehicles with smooth trays and sides. (c) The trays of vehicles transporting bituminous materials may be lubricated with

soap solution or light oil sprayed on the trays. Vehicles transporting bituminous friction course material shall not be lubricated with light oil.

9.4 SUBMISSIONS 9.4.1 Particulars of filler and bitumen for bituminous materials

(a) The following particulars of the proposed filler and bitumen for bituminous materials shall be submitted to the Project Manager for review:

(i) a certificate from the manufacturer for each type of filler showing the

manufacturer's name, the date and place of manufacture and showing that the filler complies with the Specification and including results of tests for particle size distribution; and

(ii) a certificate from the manufacturer for bitumen showing the

manufacturer's name, the date and place of manufacture and showing that the bitumen complies with the Specification, including a temperature-viscosity relationship for the bitumen, and including results of tests for: • relative density; • softening point; • penetration; • ductility; • retained penetration after thin film oven test; • solubility; • viscosity; and • loss on heating.

(b) Further certificates showing that the materials comply with the Specification

shall be submitted at intervals reviewed without objection by the Project Manager.


9.4.2 Particulars of mixes for sub-base material and bituminous materials

(a) The following particulars of sub-base material and bituminous roadbase materials shall be submitted to the Project Manager for review:

(i) source and type of aggregates;

(ii) grading details in tabular and graphical form; and

(iii) details of each mixing plant proposed.

(b) The following particulars of bituminous materials shall be submitted to the

Project Manager for review:

(i) certified copies of work sheets for mix designs, which shall include the relative density of the mixed aggregates;

(ii) source of bitumen; and

(iii) past test records of the same mix produced in the same plant.

9.4.3 Particulars of supplier of sub-base material and bituminous materials

The name of the supplier and the location of each plant from which the Contractor proposes to obtain sub-base material and bituminous materials shall be submitted to the Project Manager for review, together with a certificate of origin and certificate of quality.

9.4.4 Particulars of methods of laying and compacting sub-bases and bituminous

materials

(a) The following particulars of the proposed methods of laying and compacting sub-bases and bituminous materials shall be submitted to the Project Manager for review:

(i) details of Contractor's Equipment; and

(ii) programme and rate of working.

9.4.5 Representative samples of sub-base material, aggregate, filler and bitumen

One representative sample of each type of sub-base material, and one representative sample of each type of aggregate, filler and bitumen for bituminous material of each proposed suppliers shall be submitted to the Project Manager at the same time as particulars are submitted.

9.5 WORKMANSHIP 9.5.1 Mixing of sub-base material and bituminous materials

Mixing of sub-base material and mixing of bituminous materials shall be carried out before delivery to Site at mixing plants reviewed without objection by the Project Manager. The plants shall be designed and operated to produce uniform mixes which comply with the specified requirements.


9.5.2 Mixing plant for bituminous materials

(a) The mixing plant for bituminous materials shall have at least four separate cold feed bins for preliminary cold batching of the coarse and fine aggregates, and a rotary drum dryer which will continuously agitate the aggregates during the heating and drying processes. After passing through the dryer, the aggregates shall be screened into at least four hot storage bins before mixing.

(b) Bitumen heating and storage tanks shall be fitted with circulating pumps to

ensure an even temperature throughout the tanks. (c) The mixing plant shall be provided with sampling devices to enable samples of

hot aggregates, filler and bitumen to be taken before mixing. (d) Insulated surge bins, if fitted to the mixing plant, shall be designed and

operated to prevent segregation occurring in the mix. Heating devices fitted to surge bins shall be capable of maintaining the temperature of the mix to within the specified limits.

(e) Measuring and weighing equipment shall be maintained in a clean, serviceable

condition. The equipment shall be set to zero daily and calibrated before mixes for the Permanent Works are produced, and at regular intervals not exceeding 6 months.

9.5.3 Mixing bituminous materials

(a) Aggregates and filler for bituminous materials shall be measured to an accuracy of ±3.0% by mass. The aggregate moisture content after drying shall not exceed 0.4% by mass.

(b) Mixing of bituminous materials shall continue after the addition of all

constituents for such period as is necessary to ensure that the aggregates and filler are uniformly coated with bitumen.

(c) Bituminous materials shall comply with the temperature requirements as

stated in Table 9.5 during and after mixing.

Table 9.5: Temperature Requirements for Bituminous Materials

Type of bituminous material

Roadbase, base course and wearing

course

Friction course

Aggregate temperature at mixing ( °C) Min. 130 115 Max. 175 135 Binder temperature at mixing ( °C) Min. 135 115 Max. 165 165 Bituminous mixture temperature Min. 130 115 after mixing ( °C) Max. 165 135 Bituminous mixture temperature Min. - 110 at laying ( °C) Max. - 135 Bituminous mixture temperature Min. - 85 at start of compaction ( °C)


9.5.4 Installation of utilities

(a) Pipes, cables, manholes, chambers, gullies and other utilities below carriageways shall be completed and fill material shall be deposited and compacted in trenches before the carriageway is constructed. Openings to manholes, chambers and gullies shall be protected by temporary covers.

(b) Covers, frames and other hardware which will prevent continuous laying of

bituminous materials for roadbase and base course shall not be fixed in position until such work is complete.

(c) After the penultimate layer of bituminous material has been laid and

compacted, the layers of asphalt shall be cut out, temporary covers shall be removed and the permanent covers, frames and other hardware shall be installed.

(d) Finishing around covers, frames and other hardware shall be carried out using

bituminous material of the same type as that in the adjacent surface. The material shall be compacted in layers not exceeding 50 mm thick using handrammers or mechanical equipment up to the underside of the wearing course or friction course.

9.5.5 Laying and compaction of sub-base material

(a) Sub-base material shall be laid and compacted in a manner which will not result in segregation of the material and at a moisture content which allows the compaction stated in Clause 9.5.5(f) to be achieved. The moisture content shall not be less than 2%.

(b) Sub-base material shall be laid in layers and compacted. The thickness of

each compacted layer shall not exceed 225mm. The minimum thickness of each layer shall be 100mm and, if the layers are of unequal thickness, the lowest layer shall be the thickest.

(c) Each layer of sub-base material shall be evenly spread immediately after

placing in position and shall be compacted immediately after spreading. (d) The minimum compaction plant to be used for compaction of sub-base

material shall be of the type as stated in Clause 9.5.9(a). (e) The Project Manager shall be notified before the next layer is placed on each

layer of compacted sub-base material. (f) Sub-base material shall be compacted to obtain a relative compaction of at

least 95% maximum dry density throughout. (g) The surface of each layer of sub-base shall be maintained in a compacted

condition until the next layer of sub-base material or roadbase material is laid; the surface shall not be disturbed by Contractor's Equipment or other vehicles, and shall be free from ridges, cracks, loose material, pot-holes, ruts or other defects.


9.5.6 Laying and compaction of bituminous materials

(a) Bituminous materials shall not be laid during periods of wet weather or when ponded water is present on the underlying surface.

(b) Bituminous wearing course material shall not be laid when the ambient air

temperature is below 8°C and bituminous friction course material shall not be laid when the ambient air temperature is below 10°C. Temperatures shall be measured in the shade near to the surface on which laying is to be carried out.

(c) Surfaces on which bituminous materials are laid shall be clean and free from

mud, grit and other deleterious material. (d) A tack coat of bituminous emulsion shall be applied to surfaces on or against

which bituminous materials will be laid. The tack coat shall be evenly applied at a rate of between 0.4 L/m² and 0.6 L/m² using a spray machine complying with BS 434 : Part 2. Bituminous materials shall not be laid until the tack coat has cured. Contractor's Equipment and other vehicles shall only run on the tack coat as necessary to lay the bituminous materials.

(e) If permitted by the Project Manager, surfaces of existing carriageways may be

regulated before the overlying bituminous material is laid; bituminous regulating course material shall be a material reviewed without objection by the Project Manager complying with the requirements for the 10 mm nominal maximum aggregate size wearing course material as specified in Table 9.3. Regulating course material shall be laid by paving machines.

(f) Bituminous materials shall comply with the temperature requirements as

stated in Table 9.5 during laying and compaction. (g) Where paved hard shoulders are provided, friction course shall be left proud of

the immediate underlying layer and in line with the front edge of the gully gratings or drainage channel, provided the friction course extends more than 0.5 m beyond the lane edge.

9.5.7 Laying bituminous materials by paving machine

(a) Bituminous materials shall be placed and spread using a self-propelled paving machine with a screw auger and attached screed capable of spreading and laying the material to the full width required. The paving machine shall be capable of giving initial compaction to the material and finishing it to a level suitable for subsequent compaction.

(b) Paving machines may be fitted with cut-off shoes or extensions to limit or

extend the width of the screed; screed extensions shall not be used unless the screw auger is extended in accordance with the manufacturer's recommendations. The surface texture produced by paving machines shall be free from segregation and from pushing or dragging marks.

(c) Bituminous materials laid by paving machines shall be placed directly from the

vehicles transporting the material into the hopper of the paving machine. Delivery of materials to the paving machine and laying of the materials shall be at a uniform rate appropriate to the capacity of the paving machine and compaction plant.


(d) If any delay in laying operations occurs, the paving machine shall be removed, the uncompacted cold material shall be removed and a transverse joint shall be formed as stated in Clause 9.5.10.

(e) Paving machines working in echelon shall be as close as practicable; the

machines shall be not more than 30 m apart unless a longitudinal joint is formed as stated in Clause 9.5.10.

(f) Manual placing of materials on freshly laid surfaces shall only be used for the

purpose of locally correcting levels as paving operations proceed, before compaction by rolling is commenced.

9.5.8 Laying bituminous materials by manual methods

Bituminous materials shall be laid by manual methods only if in the opinion of the Project Manager the use of a paving machine is impracticable. If permitted by the Project Manager, bituminous materials may be laid by manual methods:

(a) in courses of irregular shape and varying thickness;

(b) in confined locations;

(c) adjacent to expansion joints, covers, frames and other hardware; and

(d) in reinstatements to trenches.

9.5.9 Compaction of bituminous materials and sub-base material

(a) The minimum compaction plant to be used to compact bituminous roadbase, base course, regulating course, wearing course and sub-base material shall be:

(i) a smooth three-wheeled steel-wheeled roller with a mass of between 6 t

and 12 t, or a vibratory tandem steel-wheeled roller with an effective mass of between 6 t and 12 t, and a smooth pneumatic tyred-roller with a mass of between 12 t and 25 t, and with not less than seven overlapping wheels which have tyres that are capable of having pressures varying between 300 MPa and 800 MPa, and suitable mechanical rammers and hand-tools; or

(ii) other types of rollers, vibrating plates and rammers reviewed without

objection by the Project Manager, or other similar plant reviewed without objection by the Project Manager, necessary to produce the required degree of compaction.

(b) Bituminous roadbase, base course, regulating course and wearing course

materials shall be initially rolled using a steel-wheeled roller operated in a longitudinal direction along the carriageway with the driving wheels nearest the paving machine.

(c) All roller marks shall be removed from the surface of bituminous roadbase,

base course and wearing course materials using either a smooth-wheeled dead-weight roller or a smooth-wheeled vibratory roller in non-vibrating mode.


(d) Bituminous friction course material shall be compacted using rollers as stated in Clause 9.5.9(a)(i) without the application of vibration; rollers shall not have an excessive film of water over the front and rear wheels. Bituminous friction course material shall be compacted until all roller marks are removed and the required degree of compaction is achieved.

(e) Rollers shall not be parked on newly laid or compacted bituminous materials. (f) Bituminous materials immediately adjacent to kerbs, covers, frames and other

hardware where rollers cannot operate effectively shall be compacted using hand-operated mechanical compaction plant.

9.5.10 Joints in bituminous materials

(a) The screed of the paving machine shall overlap previously laid strips of bituminous material by at least 50 mm and shall be sufficiently high that compaction will produce a smooth dense flush joint. Bituminous materials overlapping the previously laid strip shall be pushed back to the edge of the previously laid strip and the excess material shall be removed.

(b) Longitudinal joints in friction course or wearing course shall be formed

coincident with the specified position of the lane-markings. (c) A prepared joint shall be formed between hot bituminous material and cold

material or existing bituminous material which is at a temperature below the minimum specified laying temperature.

(d) The distance between prepared longitudinal joints in different layers shall be at

least 150 mm and the distance between prepared transverse joints in different layers shall be at least 500 mm.

(e) Prepared joints in base course and wearing course shall be formed by cutting

back the face of the cold material or existing bituminous material for a minimum distance of twice the depth of the layer or 100 mm, whichever is greater; a vertical face shall be cut for the full depth of the layer. All loosened materials shall be removed and the face shall be coated with bituminous emulsion; the bituminous emulsion shall not be applied beyond the edges of the joint. The hot bituminous materials shall be laid and compacted against the coated face with a joint formed as stated in this sub-section.

(f) Friction course joints shall not be coated with bituminous emulsion. 9.5.11 Protection of surfaces of sub-base material and bituminous materials

(a) The surface of each layer of sub-base material and bituminous materials shall be kept clean and free from deleterious material. Bituminous priming coat shall be applied to the final surface of the sub-base layer at a rate of between 0.9 L/m² and 1.1 L/m².

(b) Layers of carriageways under construction shall not be used by Contractor's

Equipment or vehicles other than those which are essential to construct the work.

(c) Bituminous courses shall not be used by Contractor's Equipment or other

vehicles until 6 hours after the material has been laid and compacted.


9.5.12 Tolerances: alignment of carriageway

The line of the edges of carriageways shall be within 25 mm of the specified line, except at the edges of structures where it shall be within 6 mm.

9.5.13 Tolerances: level of carriageway

(a) The levels of the surface of each layer of sub-base, roadbase, base course, wearing course and friction course shall be determined on a grid at 10 m centres in the longitudinal direction and at 2 m centres in the transverse direction.

(b) The level of the surface of each layer of sub-base, roadbase, base course,

wearing course and friction course shall be within the tolerances stated in Table 9.6.

(c) The difference in level of the surface of wearing course and friction course

across joints shall not exceed 3 mm. (d) The combination of permitted tolerances in levels shall not result in a reduction

in the thickness of the pavement, excluding the sub-base, of more than 15 mm from the specified thickness nor a reduction in the thickness of the bituminous wearing course or friction course of more than 5 mm from the specified thickness.

Table 9.6: Tolerances in Level

Type of surface Permitted tolerance in level (mm)

Sub-base + 10 - 20

Roadbase course + 8 - 15

Base course

Wearing course ± 6

Friction course 9.5.14 Tolerances: covers, frames and other hardware

The level of covers, frames and other hardware shall be not lower than, and shall not be more than 5 mm higher than the surface of the carriageway. The level of gully gratings shall not be higher than, and shall not be more than 5 mm lower than, the surface of the carriageway.


9.6 INSPECTION, TESTING AND COMMISSIONING 9.6.1 Trial areas

(a) The Contractor shall produce trial areas of each type and layer of bituminous materials to demonstrate that the proposed materials, mixes, methods of production and methods of construction are capable of producing a carriageway which complies with the specified requirements. Unless otherwise stated in the Contract, the trial areas shall be constructed as part of the Permanent Works at locations reviewed without objection by the Project Manager. The width of each trial area shall be at least one lane of carriageway, and the length shall be at least 60 m.

(b) Trial areas shall be constructed using the materials, mixes, methods of

production and methods of construction submitted to and reviewed without objection by the Project Manager. Materials shall be delivered in not less than two loads.

(c) The Contractor shall notify the Project Manager 48 hours before constructing

trial areas. (d) The Contractor shall notify the Project Manager before each layer of material

is placed in the trial area. (e) The Contractor shall not proceed placing materials of the same type in the

permanent carriageway until he obtains a notice of no objection from the Project Manager.

Table 9.7: Sampling and Testing Bituminous Materials

Type of material Properties Methods of sampling

Methods of testing

Bituminous base course and wearing course material

Particle size distribution Bitumen content Rice's specific gravity Void content

Clause 9.6.13(b) Clause 9.6.13(b) Clause 9.6.13(b) Clause 9.6.15(a)

Clause 9.6.13(c) Clause 9.6.13(c) Clause 9.6.13(c) Clause 9.6.15(b)

Bituminous friction course material

Particle size distribution Bitumen content Texture depth and permeability

Clause 9.6.14(b)

Clause 9.6.14(b)-

Clause 9.6.14(a) Clause 9.6.14(a) Clause 9.6.16(a)

9.6.2 Samples: trial areas

(a) One sample of bituminous materials, excluding bituminous roadbase materials, shall be provided from each mix used in trial areas. The method of sampling shall be as stated in Table 9.7

(b) Ten cores shall be cut from each layer of base course and wearing course in

trial areas. The method of taking cores shall be as stated in Clause 9.6.15 (a).


9.6.3 Testing: trial areas

(a) Each sample of bituminous material taken as stated in Clause 9.6.2, shall be tested to determine the properties stated in Table 9.5. The method of testing shall be as stated in Table 9.5.

(b) If the layer is to form part of the Permanent Works, each layer of bituminous

material in trial areas, excluding bituminous roadbase material, shall be tested as stated in Clause 9.5.13 to determine the level of the surface.

(c) The layer which is to be the final layer of the carriageway in each trial area

shall be tested as stated in Clauses 9.6.9 (a) and 9.6.9 (b) to determine the surface regularity, if the layer is to form part of the Permanent Works.

(d) The layer of friction course in each trial area shall be tested as stated in

Clauses 9.6.16 (a) to 9.6.16 (c) to determine the texture depth and permeability.

(e) Cores shall be tested as stated in Clauses 9.6.15 (a) to 9.6.15 (d) to determine

the compacted layer thickness and air void content. 9.6.4 Compliance criteria: trial areas

The properties of the materials, the levels of the surface, compaction, surface regularity, texture depth and permeability of bituminous materials laid in the trial areas shall comply with the specified requirements for the permanent carriageway.

9.6.5 Non-compliance: trial areas

(a) If the result of any test on trial areas does not comply with the specified requirements for trial areas, particulars of proposed changes to the materials, mixes, methods of production or methods of construction shall be submitted to the Project Manager for review and further trial areas shall be constructed until the result of every test on trial areas complies with the specified requirements for the trial areas.

(b) Trial areas, or parts of trial areas, which do not comply with the specified

requirements for the trial area shall be removed. 9.6.6 Acceptable mix for bituminous materials other than bituminous roadbase

material

(a) A mix for bituminous materials other than bituminous roadbase material which complies with the specified requirements for designed mixes and for trial areas is defined as an "Acceptable Mix".

(b) The "Acceptable Gradation Envelope" for bituminous materials other than

bituminous roadbase material is defined as the gradation envelope found by applying the tolerances stated in Table 9.8 to the particle size distribution of the "Acceptable Mix".

(c) The "Acceptable Bitumen Content Range" for bituminous materials other than

bituminous roadbase material is defined as the bitumen content range formed by applying a tolerance of ±0.5% to the bitumen content of the "Acceptable Mix".


Table 9.8: Tolerances for Particle Size Distribution from Acceptable Mix

Tolerance of particle size distribution in percentage By mass of total mix passing BS test sieve

BS test sieve Nominal maximum aggregate size (mm) 37.5 28 20 10

50 mm 0 - - - 37.5 mm ± 4 0 - - 28 mm ± 7 ± 4 0 - 20 mm ± 7 ± 7 ± 4 - 14 mm ± 7 ± 7 ± 7 0 10 mm ± 7 ± 7 ± 7 ± 4 5 mm ± 7 ± 7 ± 7 ± 7 2.36 mm ± 7 ± 7 ± 7 ± 7 1.18 mm ± 7 ± 7 ± 7 ± 7 600 μm ± 5 ± 5 ± 5 ± 5 300 μm ± 5 ± 5 ± 5 ± 5 150 μm ± 3 ± 3 ± 3 ± 3 75 μm ± 2 ± 2 ± 2 ± 2

9.6.7 Commencement of placing bituminous materials

Bituminous material shall not be placed in the Permanent Works until the mix has been reviewed without objection by the Project Manager.

9.6.8 Changes in materials and methods of construction

The materials and methods of production used in producing the mixes and the methods of construction used in trial areas shall not be changed after having been reviewed without objection by the Project Manager.

9.6.9 Testing: surface regularity

(a) Testing method

The surface regularity of the final layer of the pavement shall be determined as stated in Clause 10.5.8(a).

(b) Compliance criteria: surface regularity

The results of tests for surface regularity shall comply with Clause 10.5.8(b)

9.6.10 Testing : Sub-Base Material

(a) Batch: sub-base material

A batch of sub-base material is a quantity not exceeding 250 m³ of sub-base material of the same type and same mix produced at the same mixing plant, and delivered to Site at any one time.

(b) Samples: sub-base material

(i) One sample of each type of sub-base material shall be provided from

each batch of sub-base material delivered to Site. (ii) The size of each sample shall be at least 50 kg. The method of

sampling shall be in accordance with BS 812 : Part 102.


(c) Testing: sub-base material

(i) Each sample of sub-base material shall be tested to determine the particle size distribution, ten percent fines value, maximum dry density, optimum moisture content and plasticity index of the portion passing a 425μm BS test sieve.

(ii) The method of testing for particle size distribution shall be in accordance

with BS 812:Part 103.1.

(iii) The method of testing for ten percent fines value shall be in accordance with BS 812:Part 111, except that the sample shall be soaked in water at room temperature for 24 hours and shall not be oven-dried before testing.

(iv) The method of testing for plasticity index shall be in accordance with

GEO Report No. 36, Tests 2.4.3 and 2.5.3, except that sample preparation shall be by wet sieving the material over a 425 μm BS test sieve.

(v) The method of testing for maximum dry density and optimum moisture

content shall be in accordance with BS 1377 : 1975, Test 13, and Appendix 7.5 of this General Materials and Workmanship Specification.

9.6.11 Testing : Relative Compaction Of Sub-Base

(a) Testing methodology

(i) Each area of sub-base which contains sub-base material of the same type and same mix produced at the same mixing plant and which is laid and compacted in a single layer in one day shall be tested to determine the relative compaction. Tests shall be carried out after the sub-base material has been laid and compacted in the final position.

(ii) Two tests shall be carried out on each area of 1000 m² or part thereof

laid and compacted each day.

(iii) Tests shall be carried out at positions which are representative of the area of compacted sub-base as a whole.

(iv) The method of testing for relative compaction shall be as stated in

Clause 7.6.17(d) Method 1 for fill material, except that the determination of maximum dry density shall be in accordance with Clause 9.6.10(c)(v), and the in-situ density in accordance with Clause 7.6.17(e).

(b) Compliance criteria: relative compaction of sub-base

The results of tests for relative compaction of sub-base shall comply with the requirements stated in Clause 9.5.5(f).

(c) Non-compliance: relative compaction of sub-base

If the result of any test for relative compaction of sub-base does not comply with the specified requirements for relative compaction of sub-base, the area shall be re-compacted and two additional tests for relative compaction of sub-base shall be carried out on the area.


9.6.12 Testing : Aggregates, Filler And Bitumen For Bituminous Materials

(a) Batch: aggregates, filler and bitumen for bituminous materials

A batch of aggregate, filler or bitumen for bituminous materials is any quantity of aggregate, filler or bitumen for bituminous materials of the same type, manufactured or produced in the same place and covered by the same certificates delivered to Site at any one time.

(b) Samples: aggregates, filler and bitumen for bituminous materials

(i) One sample of each type of aggregate, filler and bitumen for bituminous

materials shall be provided from each batch.

(ii) The size of each sample and the method of sampling shall be as stated in Table 9.9.

Table 9.9: Size of Samples and Method of Sampling for Aggregates, Filler and Bitumen

Material Minimum size

of sample Method of sampling

Aggregate, nominal maximum aggregate size exceeding 28 mm 50 kg

BS 812:Part 102 Aggregate, nominal maximum aggregate size 5 mm to 28 mm 25 kg

Aggregate, nominal maximum aggregate size less than 5 mm 10 kg

Filler 5 kg ASTM D 242 Bitumen 2 litres ASTM D 140

(c) Testing: aggregates, filler and bitumen for bituminous materials

Each sample of aggregate, filler and bitumen for bituminous materials shall be tested to determine the properties stated in Table 9.10. The method of testing shall be as stated in Table 9.10.


Table 9.10: Testing Aggregates, Filler and Bitumen for Bituminous Materials

Material Property Method of testing Coarse aggregate Relative density

Water absorption BS 812 : Part 2

Ten percent fines value BS 812 : Part 111 Particle size distribution BS 812 : Part 103.1 Flakiness index BS 812 : Part 105 Fine aggregate Relative density

Water absorption BS 812 : Part 2

Particle size distribution GEO Report No. 36, test 2.9.2B

Filler Relative density BS 4550 : Part 3 Particle size distribution BS 812 : Part 103.1 Bitumen Relative density ASTM D 3289 Softening point BS 2000 Penetration ASTM D 5 Ductility ASTM D 113 Retained penetration

after thin film oven test ASTM D 1754

Solubility ASTM D 2042 Viscosity ASTM D 2171 or BS 2000 Loss on heating BS 2000

9.6.13 Testing : Bituminous Materials Other Than Bituminous Friction Course

Material

(a) Batch: bituminous materials other than bituminous friction course material

A batch of bituminous materials other than bituminous friction coarse material is a quantity not exceeding the limits stated in Table 9.11 of bituminous materials of the same type and same mix produced at the same mixing plant in one day.

Table 9.11: Maximum Size of Batch for Bituminous Materials other than

Bituminous Friction Course Material

Material Maximum batch size (t)

Wearing course 100

Base course 150

Road base 200

(b) Samples: bituminous materials other than bituminous friction course material

(i) One sample of bituminous material other than bituminous friction course material shall be provided from each batch unless otherwise required by the Project Manager.


(ii) The size of each sample shall be as stated in Table 9.12.

(iii) Samples shall be taken at the mixing plant or at the location where the bituminous material will be laid as directed by the Project Manager. Samples taken at the mixing plant shall be taken from the delivery vehicle immediately after loading from the plant or from the surge bin. Samples taken at the location where the bituminous materials will be laid shall be taken from the delivery vehicle.

(iv) The method of sampling shall be in accordance with ASTM D 979.

Table 9.12: Size of Samples for Bituminous Materials other than Bituminous

Friction Course Material

Material Minimum size of sample (kg) Wearing course (10mm nominal maximum aggregate size)

10

Wearing course (20mm nominal maximum aggregate size)

16

Base course 24 Roadbase 24

(c) Testing: bituminous materials other than bituminous friction course material

(i) Each sample of bituminous materials taken as stated in Clause 9.6.13(b)

(i) shall be tested to determine the particle size distribution, bitumen content and Rice's specific gravity.


Particle size distribution : ASTM C 136 with modifications and

ASTM C 117, Method B Bitumen content : ASTM D 2172, Method A Rice's specific gravity : ASTM D 2041, Weighting-in-water

method Bulk specific gravity : ASTM D 2726


(iii) For particle size distribution tests in accordance with ASTM C 136, the modifications are:

Sieves to BS410 instead of sieves to ASTM E11 shall be used. Each sample of bituminous materials taken as stated in Clause 9.6.13(b) shall be reduced to test specimen of suitable size as follows:

Nominal Maximum Minimum Sample Size (kg) Aggregate Size (mm)

37.5 2.5 28.0 2.0 20.0 1.5 10.0 1.0

(iv) The residual pressure manometer specified in ASTM D 2041 shall be

replaced by a vacuum gauge.

(d) Compliance criteria : bituminous materials other than bituminous friction course material The results of tests on bituminous materials other than bituminous friction course material shall comply with the following requirements:

(i) The particle size distribution shall be such that not more than two points

on the particle size distribution curve are outside the "Acceptable Gradation Envelopes" determined as stated in Clause 9.6.6(b). The percentage passing the 75 μm BS test sieve shall not exceed the acceptable design value by more than 3%.

(ii) The bitumen content shall be within the "Acceptable Bitumen Content

Range" determined as stated in Clause 9.6.6(c). 9.6.14 Testing : Bituminous Friction Course Material

(a) Batch: bituminous friction course material

A batch of bituminous friction course material is a quantity not exceeding 100 t of bituminous friction course material of the same mix produced at the same mixing plant in one day.

(b) Samples: bituminous friction course material

(i) One sample of bituminous friction course material shall be provided from

each batch of bituminous friction course material.

(ii) The size of each sample shall be at least 15 kg.

(iii) Samples shall be taken at the mixing plant from the delivery vehicle immediately after loading from the plant or from the surge bin.

(iv) The method of sampling shall be in accordance with ASTM D 979.


(c) Testing: bituminous friction course material

(i) Each sample of bituminous friction course material shall be tested to determine the particle size distribution and bitumen content.


Particle size distribution : ASTM C 136 with modifications and ASTM C 117, Method B Bitumen content : ASTM D 2172, Method A

(iii) For particle size distribution tests in accordance with ASTM C 136, the

modifications are:

Sieves to BS410 instead of sieves to ASTM E11 shall be used. Each sample of bituminous materials taken as stated in Clause 9.6.14(b) shall be reduced to test specimen of suitable size as follows:

Nominal Maximum Minimum Sample Size (kg) Aggregate Size (mm)

37.5 2.5 28.0 2.0 20.0 1.5 10.0 1.0

(d) Compliance criteria: bituminous friction course material

The results of tests on bituminous friction course material shall comply with the following requirements:

(i) The particle size distribution shall be within the "Acceptable Gradation

Envelopes" as determined in Clause 9.6.6(b).

(ii) The bitumen content shall be within the "Acceptable Bitumen Content Range" as determined in Clause 9.6.6(c).

9.6.15 Testing : Bituminous Material Cores

(a) Samples: bituminous material cores

(i) Each area of roadbase, base course and wearing course which contains bituminous material of the same type and same mix produced at the same mixing plant and which is laid and compacted in a single layer in one day shall be tested to determine the compacted layer thickness.

(ii) Each area of bituminous material to be tested shall be divided into

approximately equal sub-areas as stated in Table 9.13. One core shall be taken at random from each sub-area.

(iii) Cores shall not be taken from within 300 mm of covers, frames and other

hardware, or construction joints in the bituminous material.


(iv) Cores shall be taken by a mechanically operated coring machine.

(v) Cores shall be 150 mm diameter for bituminous material with a designed layer thickness of 40 mm or greater and shall be 100 mm diameter for bituminous material with a designed layer thickness of less than 40 mm.

(vi) Cores shall be taken as soon as practicable but not later than 48 hours

after completion of the paving operation.

(vii) If permitted by the Project Manager, the sampling rate for roadbase may be applied to wearing course and base course.

(viii) Holes formed by taking cores shall be filled with compatible bituminous

material as soon as practicable after the core has been taken.

Table 9.13: Rate of Sampling for Bituminous Material Cores

Area of bituminous material laid and compacted in one day

No. of sub-areas/cores

Roadbase Wearing course and Base course

< 5 000 m² 4 10 5 000 - 10 000 m² 10 15 > 10 000 m² 20 20

(b) Testing: bituminous material cores

(i) Each bituminous material core shall be measured to determine the

compacted layer thickness of the bituminous material and tested to determine the air void content.

(ii) The method of testing for air void content shall be in accordance with

ASTM D 3203.

(c) Compliance criteria: bituminous material cores

The results of tests on bituminous material cores shall comply with the following requirements:

(i) The average air void content of the cores taken from an area of

bituminous base course or wearing course material shall be not less than 3.0% and not greater than 6.0%.

(ii) The air void content of each core taken from an area of bituminous base

course or wearing course material shall be not less than 2.5% and not greater than 7.5%.

(iii) The air void content of each core taken from an area of bituminous

roadbase material shall be not less than 3.0% and not greater than 9.0%.

(iv) The compacted layer thickness as measured from each core shall

comply with the thickness requirements stated in Clause 9.5.13(d) and shall be compatible with the level tolerances stated in Table 9.6.


(d) Non-compliance: bituminous material cores

(i) If the result of any test for air void content of cores does not comply with the specified requirements for air void content, the following procedure shall apply:

• Four additional cores, shall be taken from each sub-area for which the original core did not comply with the specified requirements for air void content. The cores shall be taken at locations evenly spaced throughout the sub-area such that they are representative of the sub-area as a whole.

• Each additional core shall be tested to determine the air void content and the test results of the additional cores from the same sub-area shall be averaged.

• The average air void content of the sub-area thus obtained shall replace the original air void content of the respective sub-area. The new average air void content of the area of bituminous material tested shall then be calculated for compliance checking.

(ii) If the air void content of any of the four additional cores determined as

stated in Clause 9.6.15(b)(ii) is less than 2.5% or greater than 7.5% for bituminous base course material and bituminous wearing course material, or less than 3.0% or greater than 9.0% for bituminous roadbase material, the sub-area from which the cores were taken shall be considered as not complying with the specified requirements.

(iii) The area of bituminous material tested shall be considered as not

complying with the specified requirements for average air void content if the average air void content of the cores taken from the area does not comply with the specified requirements for average air void content.

(iv) If the result of any test for compacted layer thickness of cores is not

compatible with the requirements of Table 9.6 or Clause 9.5.13(d), four additional cores shall be taken from the same sub-area and the results averaged to determine the average compacted layer thickness. The cores shall be taken at locations evenly spaced throughout the sub-area such that they are representative of the sub-area as a whole.

(v) If the average compacted layer thickness determined as stated in Clause

9.6.15(d)(iv) is not in accordance with the permitted compacted layer thickness stated in Clause 9.6.15(c)(iv), the sub-area from which the cores were taken shall be considered as not complying with the specified requirements.

9.6.16 Testing : Texture Depth And Permeability

(a) Testing: texture depth and permeability

(i) Each area of friction course to be tested shall be divided into approximately equal sub-areas as stated in Table 9.14. Tests for texture depth and permeability shall be carried out on each sub-area at positions which are representative of the sub-area of friction course as a whole. No measurement shall be taken within 300 mm of the longitudinal edge of the carriageway.

(ii) If permitted by the Project Manager the number of tests for texture depth

and permeability may be reduced to the minimum stated in Table 9.14.


(iii) Tests shall be carried out before the area of friction course is used by Contractor's Equipment or other vehicles.

(iv) Testing to determine the texture depth will be carried out by the

Contractor in the presence of the Project Manager. The method of testing shall be by the sand patch test in accordance with Appendix 10.1.

(v) Testing to determine the permeability will be carried out by the

Contractor in the presence of the Project Manager. The method of testing shall be in accordance with Appendix A9.1.

(b) Compliance criteria: texture depth

The results of tests for texture depth on an area of course shall comply with the following requirements:

(i) the average texture depth shall not be less than 1.5 mm; and

(ii) not more than one of the tests for texture depth shall give a result of less

than 1.2 mm.

(c) Compliance criteria: permeability

The time for 150 mL of water to drain into the friction course in the permeability test stated in Clause 9.6.16(a)(v) shall not exceed 30 seconds.

Table 9.14: Rate of Testing for Texture Depth and Permeability

Area of bituminous material laid and compacted in one day

No. of sub-areas/tests

Normal Minimum< 5 000 m² 10 45 000 – 10 000 m² 15 10> 10 000 m² 20 20


APPENDIX A9.1

DETERMINATION OF THE PERMEABILITY OF FRICTION COURSE MATERIAL

A9.1.1 Scope This method covers the determination of the permeability of friction course material

by measuring the time taken for 150 mL of water to drain into the material. A9.1.2 Apparatus The following apparatus is required:

(1) a non-porous ring with an opening of internal diameter of 150 mm ± 2 mm, and a minimum height of 20 mm;

(2) suitable sealant for sealing one end of the ring onto the friction course

surface;

(3) a measuring cylinder for measuring 150 mL of water to an accuracy of 1 mL;

(4) two containers, each suitable for containing and pouring 150 mL of water; and

(5) a stop watch. A9.1.3 Procedure


(1) carefully inspect the specified test location and record any unusual features;

(2) place one end of the ring on the friction course at the location to be tested, and seal the interface with sealant to prevent any leakage of water;

(3) prepare two volumes of water of 150 mL each using the measuring cylinder

and the two containers;

(4) pour one 150 mL measure of water into the ring quickly and steadily without spillage;

(5) as soon as all of the water has drained into the friction course, pour the

second 150 mL of water into the ring quickly and steadily without spillage, and at the same time start the stop watch;

(6) record the time taken for the second 150 mL of water to drain into the friction

course surface. A9.1.4 Reporting of Results


(1) the test location; and

(2) the time taken for the second 150 mL of water to drain into the friction course surface, to the nearest one second.

General Materials & Workmanship Specification 1/20 January 2011 Issue No. 5, Volume 1 – Civil & Structural Works Section 10 – Concrete Carriageways

SECTION 10 CONCRETE CARRIAGEWAYS

10.1 GENERAL 10.1.1 General requirements

The Permanent Works and materials specified shall comply with the Sections stated, unless otherwise stated in this Section. (a) Formwork and finishes to concrete for concrete carriageways shall comply

with Section 18. (b) Steel reinforcement for concrete carriageways shall comply with Section 19. (c) Concrete for concrete carriageways shall comply with Section 20. (d) Curing compound for concrete carriageways shall comply with Section 20. (e) Earthworks for concrete carriageways shall comply with Section 7.

10.2 MATERIALS 10.2.1 Reinforcement

(a) Fabric reinforcement shall be steel fabric complying with BS 4483; the fabric shall be manufactured from steel wire which complies with BS 4482 and which has a type 2 bond classification.

(b) Dowel bars, tie bars, cradles and tie bars for cradles shall be Grade 250 plain

round steel bars complying with CS2. Dowel bars and tie bars shall be straight; both ends of dowel bars and one end of tie bars shall be sawn square with all burrs removed.

10.2.2 Cement mortar for cradles

Cement mortar for supporting cradles shall consist of 1 part of cement to 3 parts of fine aggregate together with the minimum amount of water necessary to achieve a consistency suitable for the required work. Fine aggregates shall be sand or crushed rock to BS 1200 and shall pass a 5 mm BS test sieve.

10.2.3 Fine aggregate

Fine aggregate for concrete shall be natural river-deposited sand consisting of at least 95% by mass of quartz grains.

10.2.4 Polyethylene sheeting



10.2.5 Joint filler

Joint filler shall be a proprietary type reviewed without objection by the Project Manager and shall be a firm, compressible, single thickness, non-rotting filler.

10.2.6 Joint sealant

(a) Joint sealant shall be of a grade suited to the climatic conditions of Hong Kong and shall perform effectively over a temperature range of 0°C to 60°C.

(b) Joint sealant shall be a cold poured two-part polymer-based sealant complying

with BS 5212, Type N. (c) Primers and caulking material for use with joint sealant shall be proprietary

types recommended by the joint sealant manufacturer and reviewed without objection by the Project Manager.

10.2.7 Bond breaker tape

Bond breaker tape shall be a proprietary type recommended by the joint sealant manufacturer and reviewed without objection by the Project Manager. The tape shall be a polyethylene film with adhesive applied on one side and shall be the full width of the groove.

10.2.8 Groove forming strip

(a) Groove forming strip shall be a proprietary type reviewed without objection by the Project Manager. The strip shall be a firm compressible strip of either ethylene vinyl acetate foam with a density of at least 90 kg/m³ or synthetic rubber. The strip shall be 25 mm deep and 5 mm thick and shall be sufficiently rigid to remain in position during concreting without deforming or stretching.

(b) Adhesive for groove forming strip shall be a proprietary type recommended by

the groove forming strip manufacturer and reviewed without objection by the Project Manager.

10.2.9 Sleeves for dowel bars and tie bars

Sleeves for dowel bars and tie bars shall be PVC and shall have a nominal wall thickness not exceeding 1.5 mm; the sleeves shall fit tightly to the bars.

10.2.10 Epoxy resin grout

Epoxy resin grout shall be a proprietary type reviewed without objection by the Project Manager.


10.2.11 Concrete mix

Concrete for concrete carriageways shall comply with the following requirements:

(a) concrete shall be Grade 40/20 and shall be a designed mix; (b) the concrete mix shall contain either PPFAC or a minimum of 265 kg of OPC

plus a minimum of 85 kg of PFA per m³ of compacted concrete; (c) the percentage by mass of fine aggregate to total aggregate shall be at least

30%; and (d) the workability in terms of designed slump value shall not exceed 25 mm.

10.2.12 Cementitious content of concrete

The minimum cementitious content of concrete for concrete carriageways shall be 350 kg/m³.

10.3 SUBMISSIONS 10.3.1 Particulars of materials for joints

(a) The following particulars of the proposed materials for joints in concrete carriageways shall be submitted to the Project Manager:

(i) manufacturer's literature and a certificate for joint filler showing the

manufacturer's name, the date and place of manufacture and stating that the joint filler complies with the Specification, including results of tests for: • disintegration and shrinkage; • recovery value and reduction in mass; and • extrusion;

(ii) manufacturer's literature for joint sealant, including details of the method

and time required for mixing the different components, and a certificate showing the manufacturer's name, the date and place of manufacture and stating that the sealant complies with the Specification, including results of tests for: • application life; • tack-free time; • resistance to flow; • recovery; • adhesion and cohesion in tension and compression; and • resistance to heat ageing;

(iii) manufacturer's literature and a certificate for groove forming strip

showing the manufacturer's name, the date and place of manufacture and stating that the groove forming strip complies with the Specification, including results of tests for density; and


(iv) particulars of primers and caulking material for joint sealant, adhesive for groove forming strip, bond breaker tape and sleeves for dowel bars and tie bars.

(b) The particulars, including certificates, shall be submitted to the Project

Manager at least 14 days before the first delivery of the material to Site. Certificates shall be submitted for each batch of the material delivered to Site.

10.3.2 Particulars of methods of construction

Particulars of proposed methods of construction for concrete carriageways shall be submitted to the Project Manager at least 21 days for review before the trial length is constructed.

10.3.3 Representative samples of materials

Representative samples of the following proposed materials shall be submitted to the Project Manager at the same time as particulars of the material are submitted:

(a) polyethylene sheeting; (b) joint filler; (c) bond breaker tape; (d) groove forming strip; and (e) sleeves for dowel bars, including compressible filler, and for tie bars.

10.4 WORKMANSHIP 10.4.1 Installation of utilities

(a) Pipes, cables, manholes, chambers, gullies and other utilities below concrete carriageways shall be completed and fill material shall be deposited and compacted in trenches before the carriageway is constructed. Openings to manholes, chambers and gullies shall be protected by temporary covers.

(b) Box-outs shall be formed in concrete carriageways for covers, frames and

other hardware; the covers, frames and other hardware shall be fixed in position after the main slab has been concreted and before the infill slab is concreted.

10.4.2 Preparation of formation and sub-base

Construction of concrete carriageways shall start as soon as practicable after the formation or sub-base has been completed. The formation shall be protected as stated in Clause 7.4.33 and the sub-base shall be protected as stated in Clause 9.5.11 until construction of the carriageway starts.


10.4.3 Laying polyethylene sheeting

Polyethylene sheeting below concrete carriageways shall be laid flat without creases. Laps shall be at least 300 mm and there shall be no gaps at the edges of bays.

10.4.4 Formwork

(a) Formwork for concrete carriageways shall be steel. The finish to concrete surfaces for transverse and longitudinal joints shall be Class F3; the finish to concrete surfaces for other edges of the carriageway shall be Class F2.

(b) Concrete shall not be placed against excavated surfaces or against kerbs. (c) Formwork shall not be loosened or removed until at least 7 hours after

concreting has been completed. 10.4.5 Forming joints

(a) Materials for joints in concrete carriageways shall be used in accordance with the manufacturers' recommendations or as otherwise specified in the Specification.

(b) Dowel bars, tie bars and their sleeves shall be securely fixed in position

through holes in the formwork before concreting. The bars shall be parallel to the top surface of the slab and to each other. Bars at transverse joints shall be parallel to the adjacent longitudinal joint or to the longitudinal axis of the carriageway if there is no longitudinal joint or to other lines directed by the Project Manager.

(c) Joint filler shall be cut to size before fixing and shall be securely fixed in

position to the existing concrete surface before concreting. There shall be no gaps between the joint filler and the formation. Holes in joint filler for dowel bars shall be cut to form a sliding fit to the sleeved bar.

(d) Joints shall be formed perpendicular to the top surface of the slab.

10.4.6 Transverse joints

(a) Transverse joints in concrete carriageways shall be straight and perpendicular to the longitudinal axis of the carriageway.

(b) Transverse expansion joints and transverse contraction joints shall be formed

only at the specified positions. The joints shall be continued across longitudinal joints and shall be in line and of the same type on both sides of the longitudinal joint. The joints shall be continued through kerbs, edgings and quadrants and their foundation and backing; the joint dimensions and materials shall be the same as the transverse joints with the omission of dowel bars. The location of additional contraction joints in accordance with Clause 11.5.15(c) shall be as directed by the Project Manager.

(c) The joint filler and groove for joint sealant at transverse expansion joints shall

provide complete separation of adjacent slabs.


10.4.7 Longitudinal joints

Longitudinal joints in concrete carriageways shall be formed only at the specified positions.

10.4.8 Isolation joints

Isolation joints shall be formed in concrete carriageways at manholes and chambers.

10.4.9 Forming grooves

(a) Grooves in concrete carriageways for joint sealant shall be straight, shall have parallel sides and shall be perpendicular to the top surface of the slab. The bottom of the groove shall be flat and shall be parallel to the top surface of the slab.

(b) Grooves at transverse expansion joints and at isolation joints at manholes and

chambers shall be formed by sawing the groove to the specified width and depth not less than 7 days after concreting. The grooves shall be located over the joint filler such that the upper surface of the joint filler is entirely contained in the groove.

(c) Grooves at transverse contraction joints shall be formed using one of the

following methods: (i) Method 1 :

An initial groove shall be sawn as soon as practicable after concreting without causing spalling of the edges. The width of the initial groove shall be less than the specified width of the final groove and the depth of the initial groove shall be between 1/4 and 1/3 of the thickness of the slab. The final groove shall be sawn to the specified width and depth not less than 7 days after concreting; or

(ii) Method 2 :

The final groove shall be sawn to the specified width and depth as soon as practicable after concreting without causing spalling of the edges. The centre lines of the initial and final grooves shall coincide.

(d) Grooves at transverse construction joints shall be formed by fixing groove

forming strip with adhesive to the concrete already placed before concreting the adjacent slab.

10.4.10 Protection of grooves

Before permanent sealing, grooves in concrete carriageways for joint sealant shall be protected from contamination by a temporary sealing strip.


10.4.11 Sealing joints

(a) The permanent sealing of joints in concrete carriageways shall be carried out at least 7 days after concreting.

(b) Immediately before permanent sealing, groove forming strips, temporary

seals, dirt and loose material shall be removed from the groove and the sides of the groove shall be cleaned and roughened by water jetting or sand blasting.

(c) Caulking material shall be firmly packed in the bottom of the groove if the joint

sealant is not required to extend to the bottom of the groove. (d) Bond breaker tape shall be fixed continuously and evenly along the bottom of

the groove for the full width and length of the groove. (e) Primer for the joint sealant shall be applied to the sides of the groove in

accordance with the manufacturer's recommendations. (f) Joint sealant shall be applied between the minimum and maximum drying

times of the primer recommended by the manufacturer. The components of the sealant shall be thoroughly mixed in accordance with the manufacturer's recommendations using a power operated paddle mixer for sufficient time to produce a homogeneous mass without entrapped air. The sealant shall be dispensed into the groove as soon as practicable after mixing and within the time recommended by the manufacturer.

(g) The groove shall be clean and dry at the time of applying the primer and joint

sealant. (h) Excess joint sealant shall be removed by using a purpose made finishing tool

such that the finished surface of the sealant is between 4 mm and 6 mm below the surface of the slab.

10.4.12 Placing and compacting concrete

(a) Concrete shall be placed continuously between the joints in concrete carriageways.

(b) Concrete shall be compacted by internal vibrators to produce a dense

homogenous mass. The number and types of vibrators shall be sufficient to ensure full compaction of the concrete at the rate at which it is placed. Sufficient vibrators in serviceable condition shall be kept on Site so that spare equipment is always available in the event of breakdowns.

(c) Concrete in unreinforced slabs shall be placed and compacted to the full

thickness of the slab in one operation.


(d) Unless otherwise permitted by the Project Manager, concrete in reinforced slabs shall be placed and compacted to the specified level of the fabric reinforcement; the fabric reinforcement shall be placed in position and concrete shall be placed and compacted to the remaining thickness of the slab. The time between compaction of the first layer and placing of the remaining layer shall not exceed 30 minutes unless in the opinion of the Project Manager the concrete already placed is sufficiently workable and the permission of the Project Manager has been obtained. Otherwise a construction joint shall be formed as stated in Clause 20.7.14; concrete shall not be placed against the concrete already placed for at least 24 hours.

(e) Concrete in infill slabs at covers, frames and other hardware shall be placed

and compacted after the covers, frames and hardware have been fixed in position and shall not be placed at the same time as the concrete in the main slab.

10.4.13 Construction joints

(a) Construction joints shall be formed in concrete carriageways only where permitted by the Project Manager or in cases of emergency if concreting is interrupted by adverse weather, plant breakdown or similar circumstances. Construction joints shall not be formed within 2.5 m of an existing or planned expansion or contraction joint.

(b) Transverse construction joints shall be formed by either:

(i) using formwork and cast-in tie bars; or

(ii) breaking back from an unformed edge and fixing the tie bars and

sleeves with epoxy resin grout in drilled holes. 10.4.14 Surface regulation

(a) Unless combined double beam compactor-levellers are used, after compaction the concrete in concrete carriageways shall be struck off to slightly above the levels of the formwork and the surface shall be regulated by a regulating machine or a vibrating beam.

(b) Regulating machines shall be purpose made and shall span the full width of

the slab either transversely or obliquely. The machine shall be equipped with at least two oscillating-type transverse screeds and shall be supported on a carriage.

(c) Vibrating beams shall have a steel or aluminium surface and shall be mounted

on a separate carriage. The beam shall be driven by a motor to provide a vibration frequency of at least 3500 cycles per minute.

(d) After regulation by the regulating machine or vibrating beam, the surface of

the carriageway shall be regulated by at least two passes of a scraping straight-edge with a blade length of at least 1.8 m. Scraping straight-edges which operate in conjunction with regulating machines shall pass across the surface at right angles to the longitudinal axis of the carriageway. If the surface is torn by the straight-edge, the surface shall be regulated again by the regulating machine or vibrating beam and by the scraping straight-edge.


(e) Wooden floats shall not be used to tamp and regulate small areas of the carriageway unless permitted by the Project Manager; steel floats or trowels shall not be used.

10.4.15 Surface texturing

(a) After the surface of the concrete carriageway has been regulated and before the curing compound is applied, the surface, other than the surface of channels and edges of slabs which do not require to be textured, shall be textured by brushing with a wire broom.

(b) The wire broom shall be at least 450 mm wide and shall have two rows of

tufts. The rows shall be 20 mm apart and the tufts in each row shall be at 10 mm centres and in line with the centre of the gaps between the tufts in the other row. The tufts shall contain an average of 14 wires, each of 32 gauge and initially 100 mm long. The broom shall be replaced if any tuft wears down to a length of 90 mm.

(c) The surface texture shall be produced by brushing evenly across the slab in

one direction at right angles to the longitudinal axis of the carriageway. Brushing shall be carried out after the moisture film has disappeared from the concrete surface and before the initial set is complete.

10.4.16 Curing concrete

The surface and edges of concrete carriageways shall be protected by one of the methods stated in Clause 20.7.15 except that covering with hessian, sacking, canvas or other absorbent material as stated in Method 2 shall not be used. If Method 1 is used, the curing compound shall be applied to the surface immediately after the surface has been textured and shall be applied to the edges immediately after the formwork has been removed.

10.4.17 Protection of concrete carriageway

(a) Immediately after the curing system has been applied, the concrete carriageway shall be fenced off from pedestrian traffic and covered with protective sheeting for at least 24 hours. The sheeting shall be lapped and securely held in position in such a manner that the surface of the carriageway will not be damaged.

(b) Loads from materials not forming part of the Permanent Works or from

Contractor's Equipment or other vehicles shall not be applied to the concrete carriageway until at least 7 days after concreting has been completed and until all grooves at joints have been temporarily or permanently sealed or protected.

(c) When Contractor's Equipment or other vehicles will turn on the concrete

carriageway the Contractor shall lay a 100 mm thick protection layer of mesh reinforced 30/20 concrete over the turning area. The protection concrete shall be separated from the concrete carriageway by two layers of polythene and it shall be removed by the Contractor without damage to the concrete carriageway when construction traffic ceases.


10.4.18 Tolerances: sub-base

(a) The level of the formation below concrete carriageways shall not be more than 10 mm higher, and shall not be more than 40 mm lower, than the specified level.

(b) The level of the sub-base below concrete carriageways shall not be more than

10 mm higher, and shall not be more than 20 mm lower, than the specified level.

10.4.19 Tolerances: formwork

(a) The line of formwork for concrete carriageways shall be within 10 mm of the specified line of the concrete carriageway.

(b) The level of the top of the formwork shall be within 3 mm of the specified level

of the concrete carriageway. (c) Abrupt irregularities in the line of the formwork and in the level of the top of

formwork shall not exceed 3 mm. 10.4.20 Tolerances: reinforcement

The cover to fabric reinforcement in concrete carriageways shall be within 10 mm of the specified cover.

10.4.21 Tolerances: dowel bars and tie bars

(a) Dowel bars at joints in concrete carriageways shall be within 20 mm of the mid-depth of the slab.

(b) Dowel bars shall be parallel to within 3 mm in half the length of the bar to:

(i) the longitudinal joint, or the longitudinal axis of the concrete carriageway

if there is no longitudinal joint;

(ii) the top surface of the slab; and

(iii) adjacent dowel bars. 10.4.22 Tolerances: grooves

The depth of grooves for joint sealant in concrete carriageways shall be within 3 mm of the specified depth.

10.4.23 Tolerances: covers, frames and other hardware

The level of covers, frames and other hardware shall not be higher than, and shall not be more than 3 mm lower than, the surface of the adjacent carriageway.


10.4.24 Tolerances: alignment of concrete carriageway

(a) The best fit straight line of straight joints and of straight edges of concrete carriageways shall be within 25 mm of the specified line. The line of straight joints and of straight edges of concrete carriageways shall be within 10 mm of the best fit straight line.

(b) The best fit curved line of curved joints and of curved edges of concrete

carriageways shall be within 25 mm of the specified line. The line of curved joints and of curved edges of concrete carriageways shall be within 10 mm of the best fit curved line.

(c) Joints in concrete carriageways shall be continuous across intersections of

joints to within 5 mm of the best fit straight lines or best fit curved lines of each joint.

10.4.25 Tolerances: level of concrete carriageway

(a) The levels of the surface of concrete carriageways shall be determined 200 mm from the edges of each bay at 10 m centres in the longitudinal direction and at 2 m centres in the transverse direction.

(b) The level of the surface of concrete carriageways shall be within 6 mm of the

specified level. In low lying and flat areas the Contractor shall pay special attention to level control to ensure that falls on the surface of the carriageway are in the specified direction.

(c) The difference in level of the surface of concrete carriageways across joints

shall not exceed 3 mm. (d) The thickness of concrete carriageway slabs shall not be less than the

specified thickness minus 10 mm. 10.4.26 Rectification

(a) Where any tolerance is exceeded, the Project Manager will determine the full extent of the area which is out of tolerance and the Contractor shall make good the surface of the concrete carriageway as detailed in Clause 10.4.26(c).

(b) Where any joint tolerance is exceeded or joint construction does not meet

requirements stipulated elsewhere, the Project Manager will determine the full extent of the area to be made good and rectification shall comprise a minimum depth of 50 mm from the carriageway surface and a minimum distance of 50 mm from the area determined as requiring repair. Cut lines shall either be parallel to transverse joints or parallel to longitudinal joints and shall be sawn the full depth of the 50 mm. The remaining area shall be broken out by a method, reviewed without objection by the Project Manager and the repair shall be undertaken using thin bonded concrete.

(c) High areas shall be ground or milled down to within tolerance or regularity and

the surface texture to comply with Section 11. Low areas shall be rectified by cutting out the surface to a depth not less than 25 mm and replacing it with concrete of a mix and method of placement reviewed without objection by the Project Manager. Surface texture shall be restored to comply with Section 11.


10.5 INSPECTION, TESTING AND COMMISSIONING 10.5.1 Compliance criteria: trial mix concrete

The results of the tests on trial mix concrete for concrete carriageways shall comply with the following requirements: none of the six slump values shall not exceed 35 mm, and the average of the six slump values shall not exceed 30 mm.

10.5.2 Trial length

(a) A trial length of concrete carriageway shall be constructed to demonstrate that the proposed materials, mix design, methods of production and methods of construction will produce a concrete carriageway which complies with the Specification.

(b) The trial length shall be constructed using the materials, mix design, methods

of production and methods of construction submitted to and reviewed without objection by the Project Manager.

(c) Unless otherwise stated that the trial length shall be constructed in a location

separate from the permanent carriageway, the trial length shall comprise the first 30 m of the permanent carriageway. The trial length shall be constructed over a width of two bays and shall include at least one expansion joint, one contraction joint and the longitudinal joint between the bays.

(d) The Contractor shall notify the Project Manager at least 48 hours before

constructing the trial length. (e) The trial length shall be completed in sufficient time before the permanent

carriageway is constructed to allow the Project Manager a period of at least 7 days to determine if the specified requirements have been complied with in the trial length.

10.5.3 Testing: trial length

(a) The trial length shall be tested to determine the accuracy of the alignment and level, the surface regularity and the texture depth. The method of testing the surface regularity shall be as stated in Clause 10.5.8. The method of testing the texture depth shall be as stated in Clause 10.5.9.

(b) Concrete cores shall be cut from the trial length to determine the thickness of

the slab, the position of the reinforcement and joint components, the amount of segregation of the constituents and the presence of voids. The method of taking, preparing, inspecting and testing concrete cores shall be as stated in Clauses 10.5.11.

10.5.4 Compliance criteria: trial length

The results of tests on trial lengths shall comply with the following requirements:

(a) The alignment, levels and thickness of the carriageway shall comply with Clauses 10.4.24 and 10.4.25.

(b) The surface regularity shall comply with Clause 10.5.8(b).


(c) The texture depth shall comply with Clause 10.5.9(b). (d) The positions of the reinforcement and joint components shall comply with

Clauses 10.4.20, 10.4.21, 10.4.22 and 10.4.24. (e) The amount of segregation of the constituents and the presence of voids shall

comply with Clause 10.5.11(c). 10.5.5 Non-compliance: trial length

(a) If the result of any test on the trial length does not comply with the specified requirements for the trial length, particulars of proposed changes to the materials, mix design, methods of production or methods of construction shall be submitted to the Project Manager for review; further trial lengths shall be constructed until the result of every test on the trial length complies with the specified requirements for the trial length.

(b) Trial lengths, or parts of trial lengths, which do not comply with the specified

requirements for the trial length shall be removed. 10.5.6 Commencement of concreting

(a) Concrete shall not be placed in the permanent carriageway other than in a trial length until the result of every test on the trial length complies with the specified requirements for the trial length.

(b) Concrete shall not be placed in the permanent carriageway before the results

of tests for compressive strength of the trial mix are available unless the result of every other test on the trial mix and trial length complies with the specified requirements for trial mix concrete and for the trial length.


Unless permitted by the Project Manager, the materials, mix design, methods of production and methods of construction used to produce a trial length which complies with the specified requirements shall not be changed.

10.5.8 Testing: surface regularity

(a) Testing methodology: surface regularity

(i) Surface regularity of concrete carriageways shall be determined by measuring the number of irregularities in the surface. An irregularity means that the gap between the surface of the carriageway, and a 3 m straight-edge placed on the surface of the carriageway, exceeds the specified amount. Irregularities shall be measured in millimetres perpendicular to the straight-edge.

(ii) The longitudinal surface regularity of carriageways with a total length of

75 m or more shall be measured using a rolling straight-edge of the type designed by the UK Transport and Road Research Laboratory. The longitudinal surface regularity of carriageways with a total length of less than 75 m and the transverse surface regularity of carriageways shall be measured using a 3 m straight-edge.


(iii) The longitudinal surface regularity shall be measured along lines parallel to the longitudinal axis of the carriageway at approximately 0.75 m and 2.25 m from the nearside edge of each carriageway lane. The transverse surface regularity shall be measured along lines at right angles to the longitudinal axis of the carriageway at 10 m intervals along the length of the carriageway.

(iv) Testing to determine the surface regularity shall be carried out by the

Contractor in the presence of the Project Manager.

(b) Compliance criteria: surface regularity

The results of tests for surface regularity of carriageways shall comply with the following requirements:

(i) the size and number of irregularities in the longitudinal direction shall not

exceed the size and permitted number of irregularities stated in Table 10.1; and

(ii) there shall be no irregularity exceeding 4 mm in a 3 m length in the

transverse direction for Category A roads and there shall be no irregularity exceeding 7 mm in a 3 m length in the transverse direction for Category B roads.

Table 10.1: Permitted Irregularities in the Longitudinal Direction

Total length

of carriageway

Size of irregularity

Permitted number of irregularities

(Category A road)

Permitted number of irregularities

(Category B road)

< 75 m > 4 mm (9 x total length)/75 (18 x total length)/75 > 7 mm 1 2

75 m - 300 m > 4 mm 9 in any 75 m length 18 in any 75 m length > 7 mm 1 in any 75 m length 2 in any 75 m length

> 300 m > 4 mm

20 in any 300 m length 40 in any 300 m length 9 in any 75 m length 18 in any 75 m length

> 7 mm 2 in any 300 m length 4 in any 300 m length 1 in any 75 m length 2 in any 75 m length

Category A roads are roads with a legal speed limit greater than 70 km/hour; all other roads are Category B roads. Irregularities greater than 7 mm shall also be counted as greater than 4 mm. No irregularity greater than 10 mm shall be permitted.


10.5.9 Testing : Texture Depth

(a) Testing: texture depth

(i) The texture depth of concrete carriageways shall be determined by the sand patch test. Tests shall be carried out at least 2 days after the surface texturing has been carried out and before the area is used by Contractor's Equipment or other vehicles.

(ii) Each carriageway lane shall be divided into sections of equal length not

exceeding 150 m. Tests shall be carried out at ten locations on each section at approximately equal spacings as directed by the Project Manager. No measurement shall be taken within 300 mm of the longitudinal edges of the sections.

(iii) Testing to determine the texture depth shall be carried out by the

Contractor in the presence of the Project Manager. The method of testing shall be in accordance with Appendix A10.1.

(b) Compliance criteria: texture depth

The results of tests for texture depth for each section of concrete carriageway

lane shall comply with the following requirements:

(i) the average texture depth shall not be less than 0.7mm; and

(ii) not more than one out of the ten measured texture depths shall be less than 0.6 mm.

10.5.10 Testing : Concrete

(a) Testing: workability and compressive strength of concrete

Testing to determine the workability and compressive strength of concrete in concrete carriageways shall be as stated in Clauses 20.8.5 to 20.8.15 except as stated in Clauses 10.5.10 (b) and (c).

(b) Compliance criteria: workability of concrete

The average slump value of the two specimens taken from one sample of concrete shall not exceed the specified slump value by more than 10 mm.

(c) Samples: compressive strength of concrete

One sample of concrete shall be provided from each 25 m³ or 25 batches of concrete or from the amount of concrete produced each day, whichever is less.


10.5.11 Testing : Concrete Cores From Trial Lengths

(a) Samples: concrete cores from trial lengths

(i) Two concrete cores shall be provided from each bay, and one core shall be provided from each joint, of concrete carriageway in the trial length. The positions from which the cores are taken shall be as directed by the Project Manager.

(ii) Concrete cores shall be 150 mm diameter and shall be the full depth of the slab. Cores shall be taken as soon as the concrete has hardened sufficiently for the core to be taken.

(iii) The method of taking concrete cores shall be in accordance with CS 1.

(iv) Holes formed by taking concrete cores from trial lengths which form part

of the permanent carriageway shall be reinstated using the concrete mix previously reviewed without objection by the Project Manager; joints shall be repaired in accordance with the method submitted to and reviewed without objection by the Project Manager.

(b) Testing: concrete cores from trial lengths

(i) Each concrete core from trial lengths in concrete carriageways shall be

inspected to determine the thickness of the slab and the positions of the reinforcement and joint components. Each core shall be inspected for evidence of segregation of the constituents and for the presence of voids.

(ii) The method of preparing and inspecting concrete cores shall be in

accordance with CS 1.

(c) Compliance criteria: concrete cores from trial lengths

Concrete cores from trial lengths in concrete carriageways shall not show evidence of segregation. The extent of voids in the core shall be "few" in accordance with Table 4 of CS 1 and there shall be no honeycombing.

10.5.12 Testing : Materials For Joints

(a) Batch: joint filler, joint sealant

A batch of joint filler or joint sealant shall comply with Clause 20.8.24.

(b) Samples: joint filler, joint sealant

Samples of joint filler or joint sealant shall comply with Clause 20.8.25.

(c) Testing: joint filler, joint sealant

Testing of joint filler and joint sealant for joints in concrete carriageways shall be as stated in Clauses 20.8.26 and 20.8.27 except as stated in Clause 10.5.12 (d).


(d) Testing: joint sealant

Each sample of joint sealant shall be tested to determine the application life, tack-free time, resistance to flow, recovery, adhesion and cohesion in tension and compression and resistance to heat ageing. The method of testing shall be in accordance with BS 5212.


APPENDIX A10.1

DETERMINATION OF THE TEXTURE DEPTH OF CARRIAGEWAYS A10.1.1 Scope This method covers the determination of the texture depth of carriageways by the

sand patch test. A10.1.2 Materials The following material is required: dry natural sand, with a rounded particle shape, which has been washed and then

screened such that it meets the grading stated in table 10.1.1.

Table 10A.1.1 : Grading of Sand

BS test Sieve

Percentage by mass passing

600 μm 100

300 μm 95 - 100

150 μm 0 - 6 A10.1.3 Apparatus The following apparatus is required: (1) a soft brush; (2) a robust measuring cylinder having an internal diameter of 20 mm ± 2 mm and

a flat top surface such that its internal volume is 25 mL ± 0.1 mL; (3) a flat wooden disc of 65 mm diameter with a 1.5 mm thick hard rubber disc

attached to one face and a handle fixed to the other face; (4) a steel rule calibrated to 1 mm; (5) a suitable wind shield; (6) a funnel with an outlet tube at least 100 mm long with a bore of between 4 mm

and 6 mm, and capable of accepting a volume of at least 200 mL; (7) a steel straight edge for screeding off the measuring cylinder; and (8) a steel-wire brush.


A10.1.4 Procedure The procedure shall be as follows:

(1) the test location shall be at least 300 mm square. It shall be vigorously brushed ten times in two directions at right angles using the steel wire brush, and then dried and swept clean with the soft brush;

(2) sand shall be poured into the measuring cylinder to fill it to overflowing, and

any excess sand shall be screeded off using the straight edge. All sand on the outside of the cylinder shall be removed, taking care not to drop any sand onto the test location. Alternatively, this step in the procedure shall be carried out in a laboratory, and the sand transferred to a suitable container ready for pouring;

(3) the measured volume of sand shall be poured onto the centre of the test

location through the funnel to form a heap. The wind shield shall be used to protect the test location if required;

(4) the sand shall be spread outwards with a circular motion over the test location,

using the rubber-faced disc with its face parallel to the surface of the carriageway. This shall be continued until the patch of sand is approximately circular and will spread outwards no more;

(5) the size of the circular patch of sand shall be measured to the nearest 1 mm

along three diameters which are aligned at approximately 120 degrees to each other;

(6) if the difference between the maximum and minimum of the three

measurements exceeds 20% of the average of the three measurements, then all the measurements shall be discarded and the test repeated at an adjacent location; and

(7) the test shall be repeated for all the ten test locations for each section of

carriageway lane. A10.1.5 Calculation

(1) The texture depth (T) for each test shall be calculated from the equation: T = 31000 / D2 mm where: D is the average of the three diameter measurements of the sand patch

calculated to the nearest 1 mm. (2) The average texture depth for the ten tests shall be calculated.


A10.1.6 Reporting of Results The following shall be reported: (1) test location; (2) average diameter of the sand patch for each test to the nearest 1 mm;

(3) texture depth for each test to the nearest 0.1 mm; and (4) average texture depth to the nearest 0.1 mm.

General Materials & Workmanship Specification 1/24 January 2011 Issue No. 5, Volume 1 - Civil & Structural Works Section 11 – Miscellaneous Roadworks

SECTION 11 MISCELLANEOUS ROADWORKS



(a) Earthworks shall comply with Section 7. (b) Sub-base material and bituminous materials shall comply with Section 9. (c) Joints in concrete shall comply with Section 10. (d) Formwork and finishes to concrete shall comply with Section 18. (e) Steel reinforcement shall comply with Section 19. (f) Concrete shall comply with Section 20. (g) Steelwork shall comply with Section 22.

11.1.2 Unit

Unit is a term used to describe a precast concrete paving slab or an interlocking block.

11.2 DESIGN AND PERFORMANCE CRITERIA 11.2.1 Design of pedestrian guard-railing

Pedestrian guard-railing which is proposed by the Contractor as an alternative to that stated in the Contract or which is erected as Temporary Works shall be designed in accordance with BS 3049, Table 1, Class C.

11.3 MATERIALS 11.3.1 Cement mortar

Cement mortar shall consist of one part of cement to three parts of fine aggregate by volume together with the minimum amount of water necessary to achieve a consistency suitable for the required work. Fine aggregates shall be sand or crushed rock to BS 1200 and shall pass a 5 mm BS test sieve.




11.3.3 Concrete mix : profile barriers

Concrete for concrete profile barriers shall be Grade 30/20.

11.3.4 Steel: pedestrian guard-railing

Steel for pedestrian guard-railing shall comply with the following:

Hot finished seamless tubes : BS 6323:Part 3 Steel tubes and tubulars suitable for screwing to BS 21 pipe threads : BS 1387 Hot rolled sections : BS 4:Part 1 Hot rolled structural steel sections - equal and unequal angles : BS 4848:Part 4 Weldable structural steels : BS 4360.

11.3.5 Stainless steel: pedestrian guard-railing

Stainless steel for pedestrian guard-railing shall be Grade 316 S 31 and shall comply with the following:

General inspection and testing procedures and specific requirements for carbon, carbon manganese and stainless steels : BS 970:Part 1 Stainless steel tubes suitable for threading in accordance with BS 21 : BS 6362.

11.3.6 Aluminium: pedestrian guard-railing

(a) Aluminium for pedestrian guard-railing shall be H 30 TF and shall comply with the following:

Wrought aluminium and aluminium alloys for general engineering purposes

(i) plate, sheet and strip : BS 1470 (ii) drawn tube : BS 1471 (iii) bars, extruded round tubes and sections : BS 1474.

(b) Aluminium shall be anodised to Grade AA 25 in accordance with BS 1615.


11.3.7 Bolts, nuts, screws, washers and rivets

(a) Bolts, nuts, screws, washers and rivets for pedestrian guard-railing shall comply with the following:

ISO metric black hexagon bolts, screws and nuts : BS 4190 ISO metric black cup and countersunk head bolts and screws with hexagon nuts : BS 4933 Metal washers for general engineering purposes : BS 4320 Rivets for general engineering purposes : BS 4620 Wrought aluminium and aluminium alloys for general engineering purposes - rivet, bolt and screw stock : BS 1473. (b) The length of bolts shall be such that the threaded portion of each bolt


(c) Rag and indented bolts shall comply with BS1494 : Part 2. Expansion bolts

and resin bonded bolts shall be proprietary types reviewed without objection by the Project Manager and shall be capable of withstanding the design loading.

(d) Galvanized bolts, nuts, screws, washers and rivets shall be used with

galvanized pedestrian guard-railing unless shown otherwise in the Contract. Non-ferrous or stainless steel components shall be insulated from ferrous materials by a non-conductive insulator of a type reviewed without objection by the Project Manager.

11.3.8 Mesh infill Mesh infill for pedestrian guard-railing shall comply with BS 4483. The mesh infill

shall be free from surface defects, surface irregularities and mesh misalignment. 11.3.9 Storage of pedestrian guard-railing Pedestrian guard-railing shall be stored off the ground on level supports and in a

manner which will not result in damage or deformation to the guard-railing or in contamination of the guard-railing. Pedestrian guard-railing shall be protected from damage and damaged guard-railing shall not be used in the Permanent Works.

11.3.10 Beams for untensioned beam barriers

(a) Beams for untensioned beam barriers shall be formed from steel plates complying with BS 1449 : Part 1, type BHR, grade 43/25.

(b) The beams shall be capable of withstanding a tensile force of at least 300 kN

and shall not deflect by more than 40 mm when loaded centrally with a point load of 1 tonne over a simply supported span of 3 m.


(c) Beams shall comply with the following requirements:

(i) the base metal thickness shall be within 0.2 mm of the specified thickness;

(ii) the strip width shall be within + 2.5 mm and - 0 mm of the specified

width;

(iii) the camber of the strip length shall be within 8 mm of the specified camber;

(iv) the beam shall be straight to within 1.5 mm in a 1.5 m length; and

(v) angles at bends shall be within 2° of the specified angle.

(d) Bolt slots in beams for connection to posts shall be prepared in the workshop

by cold saw-cutting. The spacing of the slots shall be such that posts will be spaced at either 4 m or 2 m.

(e) Beams shall be hot-dip galvanized in accordance with BS 729 to a coating

thickness of at least 460 g/m². (f) Welds for end beam sections shall be full-penetration butt welds. (g) Beams shall be shaped so as to present no sharp edges to traffic and except

where shown on the Employer’s Drawings shall be straight and of uniform cross-section within manufacturing tolerances.

(h) The beams shall be separated from the posts by blocking-out pieces which

are fabricated from materials of the same quality as the posts. (i) Posts and blocking-out pieces shall be drilled to take the specified post bolts

for affixing the beams. 11.3.11 Posts for untensioned beam barriers

(a) Posts for untensioned beam barriers shall be formed from Grade 43A steel

complying with BS 4360. (b) Posts and blocking-out pieces shall be hot-dip galvanized in accordance with

BS 729 to a coating thickness of at least 610 g/m². (c) Posts fabricated from hollow sections shall be sealed by welding mild steel

sealing plates over the open ends; the plates shall be at least 3 mm thick. (d) Posts shall be within the tolerances stated in BS 4.

11.3.12 Anchorages for untensioned beam barriers

(a) End beam sections shall be cut and welded with full-strength butt welds. (b) Anchor blocks shall be constructed of concrete which shall be cast directly

against the sides of the excavation.


11.3.13 Cleats and struts for untensioned beam barriers

(a) Cleats and struts for untensioned beam barriers shall be fabricated from angle sections complying with BS 4 and shall be weldable structural steel complying with BS 4360, Grade 43A.

(b) Cleats and struts shall be hot-dip galvanized in accordance with BS 729 to a

coating thickness of at least 610 g/m². (c) The dimensional tolerances of steel angles for cleats and struts shall comply

with BS 4. 11.3.14 Bolts and nuts for untensioned beam barriers

(a) Bolts for untensioned beam barriers shall be M 16 size and strength grade 4.6 complying with BS 4190. Bolts for beam splicing, bolts for connecting beams to posts and bolts for connecting beams to cleats shall be round or button-headed with oval shoulders; other bolts shall be ISO metric black hexagon type.

(b) Nuts for untensioned beam barriers shall be of strength grade 4 or 5

complying with BS 4190. (c) Bolts and nuts shall be hot-dip galvanized in accordance with BS 729 to a

coating thickness of at least 375 g/m². (d) Nuts shall be tapped 0.4 mm oversize to accommodate the galvanized

coating. (e) The length of bolts shall be such that the threaded portion of each bolt


(f) Rag and indented bolts shall comply with BS1494 : Part 2. Expansion bolts

and resin bonded bolts shall be proprietary types reviewed without objection by the Project Manager and shall be capable of withstanding the design loading.

11.3.15 Washers

(a) Washers for untensioned beam barriers shall be black mild steel and shall comply with BS 4320, Form E, F or G; washers shall be manufactured from steel complying with BS 1449 : Part 1, grade 250.

(b) Plain washers shall be 2 mm thick and shall be of dimensions suitable for use

with M 16 bolts and nuts. (c) Plain washers shall be hot-dip galvanized in accordance with BS 729 to a

coating thickness of at least 375 g/m². (d) Shaped washers shall have a thickness of at least 5 mm and shall be cast

iron complying with BS 3468; the washers shall be shaped to fit the curvature of circular hollow sections used as posts.


11.3.16 Storage of beams and posts Beams and posts for untensioned beam barriers shall be stored off the ground on

level supports and in a manner which will not result in damage or deformation to the beams and posts or in contamination of the beams and posts. Beams and posts shall be protected from damage and damaged beams and posts shall not be used in the Permanent Works.

11.3.17 Concrete kerbs, edgings and quadrants

(a) Concrete for kerbs, edgings and quadrants shall be Grade 30/20. Concrete for foundations and backings to kerbs, edgings and quadrants shall be Grade 20/20.

(b) Precast concrete kerbs, edgings and quadrants shall comply with BS 7263 :

Part 1 except that the requirement for testing of water absorption shall not be applied. The nominal length of kerbs shall be 1 m and the nominal length of edgings shall be 750 mm.

11.3.18 Supply of precast concrete kerbs type K1 and K2

(a) The Contractor shall, within 6 weeks from the date for commencement of Works, submit a programme prepared to such detail as the Project Manager may require showing a month by month batch forecast of the total kerb requirements. The Project Manager will forward this programme to the Superintendent of the Tai Lam Correctional Institute who will advise whether he will be able to fulfil the order to the programme required.

(b) The Contractor shall update this programme from time to time and shall

provide the Project Manager with 3 months notice of his requirements for any particular batch. The Project Manager will forward a copy of this notice to the Superintendent who will confirm within 1 month of the date of the notice whether or not he will be able to supply the particular batch.

(c) Having regard to the progress of the Works and upon receipt of confirmation

from the Correctional Services Department that a particular batch or part thereof can be supplied the Project Manager will issue a copy of the Requisition Order to the Contractor who shall thereafter be responsible for agreeing with the Superintendent of Tai Lam Correctional Institute a suitable date and time for collection of the kerbs.

(d) If the Superintendent is unable to confirm within 1 month, as stated in

paragraph (c), that he will be able to supply any batch or part thereof or if the Project Manager so instructs the Contractor shall provide kerbs from his own source. Appropriate items are included in the Bill of Quantities for this eventuality.

11.3.19 Granite kerbs, edgings and quadrants

(a) Granite kerbs, edgings and quadrants shall be worked straight or circular. Corners shall be square and the top front and back edges shall be parallel. The length of granite kerbs and edgings shall be at least 600 mm.


(b) The ends of the kerbs, edgings and quadrants shall be chisel-dressed square to form a close butt-joint with adjacent kerbs. Kerbs shall be chisel-dressed to a depth of at least 140 mm on the front face, at least 75 mm on the back face and for the full width of the top face.

11.3.20 Concrete for footways, cycletracks and paved areas

Concrete for footways, cycletracks and paved areas shall be Grade 30/20. 11.3.21 Cobble stone paving

Cobble-stone paving shall consist of stones placed in a 100 mm thick grade 30/20 concrete bed. The stones shall be roughly elliptical and have a maximum dimension not exceeding 150mm and a minimum dimension not less than 100mm.

11.3.22 Rubble stone facing and paving Rubble stone facing and paving shall consist of random stone whose maximum

dimension on the exposed face shall not be less than 300 mm, whose minimum dimension on the exposed face shall not be less than 200 mm and whose thickness shall not be less than 200 mm.

11.3.23 Paving slabs and interlocking blocks

(a) Concrete for precast concrete paving slabs shall be Grade 30. (b) Concrete for precast concrete interlocking blocks in footways and cycletracks

shall be Grade 30; concrete for precast concrete interlocking blocks in carriageways or areas to which vehicles will have access shall be Grade 45.

(c) The nominal maximum aggregate size of aggregate for concrete in precast

units shall be 10 mm. (d) The dimensions of the precast units shall be within 3 mm of the specified

dimensions; chamfers shall not exceed 8 mm. (e) Paving slabs shall be square or rectangular and interlocking blocks shall be

rectangular unless otherwise selected in the Contract. (f) The colour of precast units shall be consistent over the area to be paved.

11.3.24 Sand for precast paving and blocking

(a) Sand for bedding precast units shall have the particle size distribution stated in Table 11.1. The sand shall have a moisture content exceeding 4% and not exceeding 8% at the time of laying.

(b) Sand for filling joints between precast units shall have the particle size

distribution stated in Table 11.2. The sand shall have a moisture content of less than 0.5% at the time of filling joints.


Table 11.1: Particle Size Distribution of Sand for Bedding Precast Units

BS test sieve size

Percentage by mass passing 10 mm 100 5 mm 85 - 100

2.36 mm 65 - 100 1.18 mm 40 - 98

600 μm 25 - 72

300 μm 10 - 35

150 μm 0 - 15

75 μm 0 - 10

Table 11.2 : Particle Size Distribution of Sand for Filling Joint between Precast Units

BS test sieve size Percentage by mass passing

2.36 mm 100

1.18 mm 90 - 100

600 μm 60 - 90

300 μm 30 - 60

150 μm 15 - 30

75 μm 5 – 10

11.3.25 Handling and storage of units Units shall be handled and stored on pallets to avoid damage to corners and

chamfer edges. Pallets shall be stored on a level base and in a manner which will not result in damage to the units or in contamination of the units. The units shall be protected from damage and damaged units shall not be used.

11.3.26 Storage of sand Sand for filling joints between units shall be stored in waterproof bags and shall be

kept under cover until used.


11.4 SUBMISSIONS 11.4.1 Particulars of concrete profile barriers

(a) The following particulars of the proposed methods of construction for concrete profile barriers shall be submitted to the Project Manager for review without objection:

(i) particulars of formwork as stated in Clause 18.5.1 for in-situ

construction using fixed forms;

(ii) details of slip-form machine for in-situ construction between sliding forms; and

(iii) methods of manufacture, handling, transport, storage and fixing in

position of precast units. 11.4.2 Particulars of pedestrian guard-railing

(a) The following particulars of the proposed pedestrian guard-railing shall be submitted to the Project Manager for review without objection:

(i) a certificate from the manufacturer showing the manufacturer's name,

the date and place of manufacture and showing that the materials comply with the requirements stated in the Contract; and

(ii) details of alternative designs proposed by the Contractor, including

drawings, showing the proposals and that the pedestrian guard-railing has been designed in accordance with Clause 11.2.1.

11.4.3 Representative samples of materials Representative samples of the following proposed materials shall be submitted to

the Project Manager for review without objection of the source and type of each material at the same time as particulars of the pedestrian guard-railing are submitted:

(a) each type of pedestrian guard-railing; (b) mesh infill; and (c) each type of bolt, nut, and washer.

11.4.4 Particulars of untensioned beam barriers

(a) The following particulars of the proposed materials and methods of construction for untensioned beam barriers shall be submitted to the Project Manager for review without objection:

(i) a certificate from the manufacturer for beams in the format stated in

BS 4360 showing the manufacturer's name, the date and place of manufacture and showing that the beams comply with the requirements stated in the Contract and including carbon equivalent values; and

(ii) details of installation method.


11.4.5 Representative samples of materials for untensioned beam barriers Representative samples of the following proposed materials shall be submitted to

the Project Manager for review without objection of the source and type of each material at the same time as particulars of the material are submitted:

(a) Beams; (b) posts, cleats and struts; and (c) bolts, nuts and washers.

11.4.6 Particulars of units

(a) The following particulars of the proposed materials and methods of construction for paving slabs and interlocking blocks shall be submitted to the Project Manager for review without objection:

(i) name and address of manufacturer;

(ii) a certificate from the manufacturer showing the manufacturer's name

and the date and place of manufacture and including results of tests for: • compressive strength of concrete cubes at 28 days; and • compressive strength of interlocking blocks; and

(iii) Contractor’s Drawings showing the layout of the units within the paved

area. 11.4.7 Representative samples of materials Representative samples of each type of unit shall be submitted to the Project

Manager for review without objection of the source and type of each unit at the same time as particulars of the unit are submitted.

11.5 WORKMANSHIP 11.5.1 Formwork: Concrete profile barriers

(a) Formwork for concrete profile barriers shall be steel. The Contractor shall take measures, reviewed without objection by the Project Manager, to avoid retention of air bubbles on the inside face of the formwork.

(b) Formwork shall not be loosened or removed until at least 7 hours after

concreting has been completed. 11.5.2 Finishes to concrete: Concrete profile barriers

(a) The finish to unformed concrete surfaces of concrete profile barriers shall be Class U5.

(b) The finish to concrete surfaces for transverse joints shall be Class F3 and the

finish to exposed concrete surfaces shall be Class F5.


11.5.3 Joints in concrete profile barriers

(a) Joints shall be formed in concrete profile barriers at locations which coincide with expansion or construction joints in the adjoining structure or carriageway or at intervals not exceeding 12 m, whichever is less.

(b) Joints in concrete profile barriers shall comply with Section 20.

11.5.4 Construction of concrete profile barriers

(a) Construction by slip-form machine

Construction of concrete profile barriers by slip-form machine between sliding forms shall be carried out in accordance with BS 5931. Slip-form machines shall comply with BS 5931, Appendix A.

(b) Construction using precast units

Precast concrete profile barriers shall be laid on a cement mortar regulating layer of between 10 mm and 40 mm thick.

11.5.5 Protection of concrete profile barriers Immediately after the formwork has been removed or the curing compound has

been applied, concrete profile barriers shall be protected by polyethylene sheeting for at least 24 hours from exposure to conditions which may affect the concrete. The sheeting shall be lapped and securely held in position in such a manner that the surface of the concrete will not be damaged.

11.5.6 Tolerances: concrete profile barriers

Concrete profile barriers shall comply with the following requirements:

(a) The horizontal dimensions of cross-sections shall be within 5 mm of the specified dimensions.

(b) The vertical dimensions of cross-sections shall be within 10 mm of the

specified dimensions. (c) The horizontal alignment along the centreline shall be within 10 mm of the

specified centreline. (d) The level of the formation shall be within 10 mm of the specified level. (e) The level of the top of the barriers shall be within 10 mm of the specified level. (f) The barriers shall form a smooth alignment.


11.5.7 Galvanizing to steel

(a) Steel components forming pedestrian guard-railing shall be hot-dip galvanized in accordance with BS 729 to a coating thickness of at least:

(i) 500g/m2 for railing other than on highway structures (ii) 600 g/m2 for highway structures

(b) Galvanizing to steel shall be applied after welding, drilling and cutting are complete.

11.5.8 Welding steel

(a) Welding for fabrication of pedestrian guard-railing shall be fillet welds. Welded surfaces shall be full depth clean and flush before application of the protective coating.

(b) Steel shall not be welded after galvanizing unless permitted by the Project

Manager; if permitted, the welded areas shall be free from scale and slag and shall be treated with a zinc-coating system reviewed without objection by the Project Manager.

11.5.9 Installation of pedestrian guard-railing

(a) Pedestrian guard-railing shall be installed to a smooth alignment to within 10 mm of the specified position and height or as directed by the Project Manager.

(b) Pedestrian guard-railing which is to be installed to a radius of less than 45 m

shall be curved in the workshop and shall not be made up of a series of straight lengths.

(c) Pedestrian guard-railing shall be fixed to concrete using rag, indented,

expansion or resin bonded bolts and shall be bolted to metalwork. Bolts for fixing to concrete shall be fitted into pockets filled with cement mortar or resin grout.

11.5.10 Installation of untensioned beam barriers

(a) Untensioned beam barriers shall be ready for assembly when delivered to Site. Beams and posts shall be free from blisters, flux, uncoated spots and other defects.

(b) The horizontal alignment of fences shall not depart from the road alignment by

more than (+ or -) 30mm nor deviate from the straight by more than 12mm in any two section lengths. The horizontal centre line of the beam shall be 600mm above the edge of the adjacent carriageway or above the datum level shown on the Employer’s Drawings, within a tolerance of (+ or -) 30mm. In addition the deviation from the straight shall not exceed (+ or -) 6mm in any two section lengths.

(c) Beams which are to be installed to a radius of less than 45 m shall be curved

in the workshop.


(d) Adjacent beams shall not connected by lap joints made in the direction of the adjacent traffic movement to avoid vehicles striking beam ends. Bolts are to be so located that they present no projection to traffic.

(e) Untensioned beam barriers shall be fixed to concrete using rag, indented,

expansion or resin bonded bolts and shall be bolted to metalwork. Bolts for fixing to concrete shall be fitted into pockets filled with cement mortar or resin grout.

11.5.11 Compacted earth footings

(a) Sub-base material shall be deposited and compacted in the bottom 250 mm of pits for foundations of untensioned beam barriers with compacted earth footings. Fine fill material shall be deposited and compacted to the remainder of the pit. The sub-base material and fill material shall be compacted to obtain a relative compaction of at least 95% throughout.

(b) Posts for untensioned beam barriers shall be securely fixed in position during

deposition and compaction of fill material. 11.5.12 Concrete footings

(a) Concrete for concrete footings shall be Grade 20/20. (b) The top surface of concrete footings shall be finished level with the adjoining

ground unless otherwise shown on the Employer's Drawings; the finish to the concrete surface shall be Class U5.

(c) Posts shall be surrounded with polyethylene sheeting before concrete is

placed and shall be securely fixed in position during concreting. 11.5.13 Anchor blocks

(a) Concrete for anchor blocks shall be Grade 20/20. (b) The finish to concrete surfaces of anchor blocks shall be Class F5 for formed

finishes and Class U5 for unformed finishes. 11.5.14 Construction of precast concrete and granite kerbs, edgings and quadrants

(a) Precast concrete and granite kerbs, edgings and quadrants shall be laid and bedded on a regulating layer of cement mortar; the thickness of the layer shall be at least 10 mm and shall not exceed 40 mm.

(b) Except as stated in this Clause, joints between each kerb, edging and

quadrant shall not exceed 10 mm in width and shall be filled and flush pointed with cement mortar. Joints in kerbs, edgings and quadrants at expansion joints on bridge decks shall be as stated in the Contract. Transverse expansion and contraction joints in kerbs, edgings and quadrants laid on or adjacent to concrete carriageways shall be in accordance with Clause 10.4.6(b).

(c) Radius kerbs shall be used for curves less than 10 m external radius.


11.5.15 Construction of in-situ kerbs, edgings and quadrants

(a) In-situ concrete kerbs, edgings and quadrants shall be constructed in accordance with BS 5931 and shall be laid by an automatic extrusion machine of a type reviewed without objection by the Project Manager.

(b) In-situ concrete kerbs, quadrants and edgings shall have regular sides,

edges, arrises and chamfers; the finish to the concrete surface shall be Class U5. Kerbs, edges and quadrants shall not be finished or dressed with cement mortar.

(c) Contraction joints shall be formed at intervals not greater than approximately 4 m. Transverse expansion and contraction joints in kerbs, edgings and quadrants which are laid on or adjacent to concrete carriageways shall be in accordance with Clause 10.4.6(b). Joints shall be flush pointed with cement mortar.

11.5.16 Tolerances: kerbs, edgings and quadrants

(a) The line of kerbs, edgings and quadrants shall be within 3 mm of the specified line.

(b) The level of the top of kerbs, edgings and quadrants shall be within 3 mm of

the specified level.

11.5.17 In-situ concrete footways, cycletracks and paved areas

(a) In-situ concrete for footways, cycletracks and paved areas shall be laid in areas not exceeding 20 m². The finish to the concrete surface shall be Class U4.

(b) Expansion joints shall be formed in concrete footways and cycle tracks at a

spacing of not more than 8 metres. 11.5.18 Flexible surfacing to footways, cycletracks and paved areas

(a) Bituminous materials for footways, cycletracks and paved areas shall be laid and compacted with steel-wheeled and pneumatic-tyred rollers. Compaction shall start before the temperature of the newly laid material falls below 100°C and shall continue until all roller marks have been removed. For locations where rollers cannot operate effectively, the bituminous material can be compacted by hand-operated mechanical compaction plant reviewed without objection by the Project Manager.

(b) Cores shall be taken in accordance with Clause 9.6.15(a) for the checking of

air void content and compacted layer thickness of the bituminous material for works with area of not less than 200 m2. For works with area smaller than 200 m2 but greater than 50 m2, at least 2 cores shall be taken from each layer of bituminous material laid. For works with area less than 50 m2, no coring is required unless otherwise instructed by the Project Manager.


(c) The cores taken in accordance with Clause 11.5.18(b) shall be tested to determine the air void content. The average air void content of the cores shall be not less than 3% nor greater than 9%. If the test result does not comply with the specified requirement, 2 additional cores shall be taken at locations agreed by the Project Manager and the average air void content determined from these 2 cores shall replace the original value for compliance checking. Notwithstanding this, no cores shall have an air void content of less than 2.5% nor greater than 10%.

(d) Each core taken from the final surfacing layer shall also be measured to

determine the compacted layer thickness that shall not deviate by more than 5 mm from the specified thickness. If the measured thickness does not comply with the requirement, 2 additional cores shall be taken at locations agreed by the Project Manager and the average thickness determined from these 2 cores shall replace the original measured value for compliance checking.

(e) If no bulk sample is taken for determination of the Rice’s specific gravity, the corresponding value obtained from the mix design shall be used in determining the air void content of the core unless other value is suggested by the Contractor and agreed by the Project Manager.

11.5.19 Protection of footways, cycletracks and paved areas Footways, cycletracks and paved areas shall not be used by Contractor's

Equipment or vehicles other than those which are essential to construct the subsequent work.

11.5.20 Cobble stone paving construction

The stones shall be placed on the concrete bed to such a depth that the nominal line of the horizontal diameter of the stones is about 10 mm below the finished concrete level. The clearance between each stone shall be 75 mm maximum and 40 mm minimum. Cement wash shall not coat the exposed surface of the stones. Before the Contractor places any cobble-stone paving in the Permanent Works he shall prepare, for review without objection by the Project Manager, a 2 m square trial panel of finished cobble-stone paving.

11.5.21 Rubble stone facing and paving construction

Stones shall be carefully shaped to obtain as close a fit as possible at beds and joints. When placed on the ground the stones shall be placed on material trimmed and compacted to make a firm bed.

Rubble stone paving stones shall be bedded on 100 mm of concrete Grade 20/40 and sufficient space shall be left between stones to allow the joints to be filled completely with concrete or mortar. The stones shall be bedded on the concrete while it is still fresh, or alternatively the concrete shall be left with a rough finish and the stones shall be bedded on a thin layer of mortar after the concrete has set. No cavities shall be left under or between the stones.


11.5.22 Laying paving slabs and interlocking blocks

(a) Laying units

(i) Paving slabs and interlocking blocks shall not be laid until the layout of the units within the paved area has been reviewed without objection by the Project Manager.

(ii) Kerbs and edgings shall be completed before the units are laid; the

compressive strength of the concrete used for in-situ concrete kerbs and edgings shall be at least 20 MPa before units are laid.

(iii) Measures shall be taken to prevent water draining across or through the

area during laying, bedding and compaction of the units.

(iv) Laying of units shall start as soon as practicable after the formation has been completed. The formation shall be protected as stated in Clause 7.4.33 until laying starts.

(v) Interlocking blocks for carriageways and paved areas to which vehicles

will have access shall be laid in a herring-bone pattern unless otherwise stated in the Contract.

(vi) Units shall be cut to size where required using mechanical cutting

devices. The cut edge shall be similar to that of an uncut unit and shall be true to line and free from chips and cracks.

(vii) On circular work where the radius is 12 m or less all flags shall be

radially cut on both edges to the required line.

(b) Laying sand

(i) A layer of sand shall be laid and shall be screeded and tamped to a uniform depth over the complete width of the area to be paved. The quantity of sand shall be sufficient to permit screeding to waste and to achieve a tamped thickness which exceeds 20 mm and does not exceed 30 mm.

(ii) The sand layer shall not be disturbed by additional compaction, foot-

marks or other damage after the layer has been screeded and tamped to the required level and before the units are laid.

(iii) Sand shall not be screeded and tamped more than 1 m in advance of

the units which have been laid.

(c) Bedding paving slabs

(i) Paving slabs shall be laid on the prepared sand layer immediately after screeding and tamping in such a manner that the sand is not disturbed.

(ii) Paving slabs shall be adjusted to form uniform joints between 2 mm and

3 mm wide and shall be bedded into the final position using a wooden mallet or a plate vibrator fitted with a rubber base-pad.


(iii) Paving slabs shall not be bedded closer than 1 m behind the laying edge other than on completion of the paved area against a kerb or edging.

(iv) Final levelling of the slabs shall be carried out as soon as practicable

after bedding and before changes in the moisture content of the prepared sand layer occur.

(v) Damaged paving slabs shall be immediately removed and replaced.

(d) Bedding interlocking blocks

(i) Interlocking blocks shall be laid on the prepared sand layer immediately

after screeding and tamping in such a manner that the sand is not disturbed. Interlocking blocks shall be individually laid on the prepared sand layer by manual methods or in clusters by mechanical methods.

(ii) Interlocking blocks shall be laid in such a manner that the blocks are not

in direct contact with each other and that uniform joints of between 2 mm and 3 mm wide are formed. Interlocking blocks shall be bedded flush by at least two passes of a heavy-duty plate compactor fitted with a rubber base-pad.

(iii) Interlocking blocks shall not be bedded closer than 1 m behind the

laying edge other than on completion of the paved area against a kerb or edging.

(iv) Final levelling of the blocks shall be carried out as soon as practicable

after bedding and before changes in the moisture content of the prepared sand layer occur.

(v) Damaged interlocking blocks shall be immediately removed and

replaced.

(e) Filling joints and compaction of units

(i) After the units have been bedded, sand for filling the joints shall be spread over the surface of the units and brushed into the joints in such a manner that all joints are completely filled.

(ii) Joints shall be filled as soon as practicable after bedding and on the day

the units are laid and bedded.

(iii) Paved areas shall be further compacted by at least two passes of a plate compactor fitted with a rubber base-pad after filling the joints to ensure that the joints are completely filled. Sand shall be added as required and compacted into the joints.

(iv) Carriageways and paved areas to which vehicles will have access shall

be compacted by at least ten evenly-spaced passes of a pneumatic tyred roller having a gross weight of between 10 t and 12 t. Sand shall be added as required and brushed and compacted into the joints.


(v) Excess sand shall be removed after completion of compaction.

(vi) Damaged units shall be immediately removed and replaced.

(f) Mortar and concrete seal Pigmented mortar or concrete shall be placed to the full depth of the unit to

form a seal between units and adjacent kerbs, edgings, quadrants, covers, frames and other hardware. The pigment shall match the colour of the adjacent units.

(g) Reinstatement of units

(i) If excavation is to be carried out in paved areas constructed using

paving slabs or interlocking blocks, the units shall be extracted by manual methods for a distance of at least 300 mm beyond the limit of the excavation.

(ii) Unbroken units shall be thoroughly cleaned to remove all sand and

deleterious material. The units shall be stacked on pallets for re-use.

(iii) Units to be re-used shall be re-laid in accordance with Clauses 11.5.22(a) to 11.5.22(f).

(h) Tolerances: paving slabs and interlocking blocks

The level of paved areas constructed using paving slabs or interlocking

blocks shall be within 3 mm of the specified level. The difference in level of adjacent slabs shall not exceed 2 mm.

11.6 INSPECTION, TESTING AND COMMISSIONING 11.6.1 Trials : Concrete profile barriers

(a) Trial length concrete profile barriers

(i) A trial length of concrete profile barrier shall be constructed to demonstrate that the proposed materials, mix design, methods of production and methods of construction will produce a concrete profile barrier which complies with the specified requirements. If it is not stated in the Contract that the trial length is to be constructed in a location separate from the permanent concrete profile barrier, the trial length shall be the first 25 m of the permanent barrier.

(ii) The trial length shall be constructed in sufficient time before the

permanent barrier is constructed to allow the Project Manager a period of at least 7 days to determine if the specified requirements have been produced in the trial length.

(iii) The Contractor shall notify the Project Manager at least 24 hours before

constructing the trial length.


(iv) The trial length shall be constructed using the materials, mix design, methods of production and methods of construction submitted to and reviewed without objection by the Project Manager.

(v) The trial length shall be used as a means of comparison against which

the Project Manager shall determine the compliance or otherwise of the permanent concrete profile barrier. The trial length shall be protected from damage and shall be left in position unless the Project Manager directs its removal. A trial length which forms part of the permanent barrier and which complies with the specified requirements shall not be removed.

(b) Testing: trial length

(i) The trial length shall be tested to determine the accuracy of the

alignment and level and the finish of the concrete surface.

(ii) Concrete cores shall be cut from the trial length to determine the amount of segregation of the constituents and the presence of voids. The method of taking, preparing, inspecting and testing concrete cores shall be as stated in Clause 11.6.2.

(c) Compliance criteria : trial length

The results of tests on trial lengths shall comply with the following requirements:

(i) The alignment and levels of the barrier shall comply with Clause 11.5.6.

(ii) The finish of concrete surfaces shall comply with Clause 18.44.

(iii) The amount of segregation of the constituents and the presence of

voids shall comply with Clause 10.5.11 for concrete carriageways.

(d) Non-compliance: trial length

(i) If the result of any test on the trial length does not comply with the specified requirements for the trial length, particulars of proposed changes to the materials, mix design, methods of production or methods of construction shall be submitted to the Project Manager for review without objection; further trial lengths shall be constructed until the result of every test on the trial length complies with the specified requirements for the trial length. Further trial mixes shall be made unless non-compliance of the trial length was not due to the concrete mix.

(ii) Trial lengths, or parts of trial lengths, which do not comply with the

specified requirements for the trial length shall be removed.

(e) Commencement of concreting

(i) Except as stated in Clause 11.6.1(e)(ii) concrete shall not be placed in the permanent barriers until the result of every test on the trial length complies with the specified requirements for the trial length.


(ii) Concrete may be placed in the permanent barriers before the results of tests for compressive strength of the trial mix are available provided that the result of every other test on the trial mix and trial length complies with the specified requirements for trial mix concrete and for the trial length.

(f) Changes in materials and methods of construction

The materials, mix design, methods of production and methods of

construction used to produce a trial length which complies with the specified requirements shall not be changed. Further trial lengths shall be constructed to demonstrate any proposed changes.

11.6.2 Testing concrete profile barriers: concrete cores from trial lengths

(a) Two concrete cores shall be provided from each trial length of concrete profile barriers. The positions from which the cores are taken shall be as directed by the Project Manager.

(b) Samples, testing and compliance criteria for concrete cores from trial lengths

shall be as stated in Clauses 10.5.11(a)(ii) to (iv), 10.5.11(b) & (c) for concrete carriageways.

11.6.3 Testing : Characteristic compressive strength of interlocking blocks

(a) Batch: interlocking blocks

A batch of interlocking blocks is any quantity of interlocking blocks of the same type and size, of the same concrete grade, manufactured in the same place, covered by the same certificates and delivered to the Site at any one time.

(b) Samples: interlocking blocks

(i) One sample of each type of interlocking blocks shall be provided from

every 1000 interlocking blocks or part thereof.

(ii) The number of interlocking blocks in each sample shall be five. (c) Testing: interlocking blocks

(i) Each sample of interlocking blocks shall be tested to determine the

characteristic compressive strength at 28 days.

(ii) The method of testing shall be as stated in Appendix 11.1.

(d) Compliance criteria : interlocking blocks

The characteristic compressive strength of a sample of interlocking blocks shall be:

(i) 30 MPa for blocks in footways and cycletracks; and

(ii) 45 MPa for blocks in carriageways and paved areas to which vehicles

will have access.


11.6.4 Testing: Grading of bedding and filling sand

(a) Batch: bedding sand

A batch of bedding sand is any stockpiled quantity of sand not exceeding a maximum batch size of 25t. Each batch shall be of the same type produced at the same time, and delivered to Site at any one time.

(b) Batch: filling sand

A batch of filling sand is any quantity of bags of filling sand of the same source, covered by the same certificate and delivered to Site at any one time.

(c) Sample: bedding or filling sand

(i) One sample of bedding or filling sand shall be provided from each batch. The method of sampling shall comply with BS 812 Part 102.

(ii) The size of each sample shall be 10 kg.

(d) Testing

(i) Each sample shall be tested to confirm compliance with the grading requirements of Table 11.1.

(ii) The method of testing shall be in accordance with BS 812 Part 103.


APPENDIX A11.1

DETERMINATION OF CHARACTERISTIC COMPRESSIVE STRENGTH OF INTERLOCKING BLOCKS

A11.1.1 Scope

This method covers the determination of the characteristic compressive strength at 28 days of interlocking blocks by means of a load test.

A11.1.2 Apparatus


(1) A compression test machine complying with CS 1. Bearing faces of the platens on the test machine shall be at least as large as the interlocking blocks and shall have a flatness tolerance of 0.05 mm.

(2) If a test machine with platens smaller than the interlocking blocks is used,

auxiliary plates of adequate size shall be placed centrally between the platens and the interlocking block to be tested. The flatness tolerance of the bearing faces of the auxiliary platens measured in accordance with CS1 shall not be more than 0.05 mm and the thickness of the plates shall be at least 25 mm.

(3) Two pieces of packing, each with a thickness of between 5 mm and 6 mm and

dimensions exceeding the interlocking block by between 15 mm and 25 mm. The packing shall be plywood, chipboard or medium density hardboard.

A11.1.3 Procedure


(1) The interlocking block shall be capped on the running surface and underside with a suitable capping material in accordance with Clause 15.5.2 of CS 1 and immersed in water for at least 24 hours before compression.

(2) The interlocking block shall be placed symmetrically on the lower platen of the

test machine, between the two pieces of packing with the running surface facing upwards.

(3) Load shall be applied without shock and shall be steadily increased at a

constant rate within a stress range of between 150 kPa/s and 700 kPa/s. (4) The load at which the interlocking block fractures shall be recorded as the

breaking load. (5) The test shall be repeated for the other four blocks.


A11.1.4 Calculation

(1) The compressive strength (C) of each interlocking block shall be calculated from the equation: W 2.5 C = __ x _______ MPa A 1.5 + L

H where:

− W is the breaking load (N) − A is the nominal gross plan area based on the manufacturing dimensions

of the interlocking blocks or the area of the tested portion if the interlocking block size is reduced for testing (mm²)

− L is the lesser of the two plan dimensions (mm) − H is the thickness of the block (mm)

(2) The unbiased standard deviation (s) shall be calculated from the following

equation: _____________ √ ΣC² - 5(Cm)² s = _______________ Mpa 4

where:

− ΣC² is the sum of the compressive strengths of the five interlocking blocks

(MPa) − Cm is the average of the compressive strengths of the five interlocking

blocks

(3) The characteristic strength (Cc) of the batch shall be calculated from the following equation: Cc = Cm - 1.65s MPa where: − Cm is the average of the compressive strengths of the five interlocking

blocks as stated in Clause A11.1.4(2) − s is the unbiased standard deviation as stated in Clause A11.1.4(2)



(1) Source, name of manufacturer and type of blocks. (2) Identification marks of blocks.

(3) Date of manufacture of blocks. (4) Nominal gross plan area of each block to the nearest 100 mm². (5) Nominal height of each block to the nearest mm. (6) Breaking load of each block to the nearest kN. (7) Compressive strength of each block to the nearest MPa. (8) Average of the five compressive strengths to the nearest MPa. (9) Unbiased standard deviation to the nearest MPa. (10) Characteristic compressive strength to the nearest MPa. (11) That the test method used was in accordance with this General Materials and


General Materials & Workmanship Specification 1/11 January 2011 Issue No. 5, Volume 1 – Civil & Structural Works Section 12 – Traffic Signs, Road Markings & Road Studs

SECTION 12 TRAFFIC SIGNS, ROAD MARKINGS AND ROAD STUDS


(a) The works and materials specified shall comply with the Sections stated, unless otherwise stated in this Section.

(i) Steelwork shall comply with Section 22.

(b) Traffic signs shall be externally illuminated, internally illuminated,

retroreflective, non-retroreflective or a combination of these types as stated in the Contract.

12.2 DEFINITIONS AND ABBREVIATIONS 12.2.1 Road Markings

Road markings are white or yellow continuous or intermittent lines, letters, characters, figures, arrows or symbols marked on the carriageway to guide road users and pedestrians.

12.3 RELEVANT CODES AND STANDARDS 12.3.1 Traffic signs

(a) Traffic signs shall comply with the Road Traffic Ordinance, Cap 374 and its subsidiary legislation. Traffic signs for road tunnels shall comply with the Road Tunnels (Government) Ordinance, Cap 368 and its subsidiary legislation.

(b) The design of traffic signs, including letters, characters, numbers, symbols and borders, shall be in accordance with conditions and restrictions imposed by the Commissioner for Transport.

(c) Unless otherwise stated in the Contract, traffic signs shall comply with the following:

Internally illuminated signs and external lighting luminaires

: BS 873 : Part 5

Retroreflective and non-retroreflective signs : BS 873 : Part 6

Posts and fittings : BS 873 : Part 7

except that the requirements for marking signs shall not apply.


12.4 MATERIALS 12.4.1 Steel

Steel for traffic signs shall comply with the following:

Hot finished seamless tubes : BS 6323 :Part 3

Hot rolled sections : BS 4 : Part 1

Hot rolled structural steel sections - equal and unequal angles

: BS 4848 : Part 4

Weldable structural steels : BS 4360 12.4.2 Stainless steel

Stainless steel for traffic signs shall be Grade 316 S 31 and shall comply with the following:

General inspection and testing procedures and specific requirements for carbon, carbon manganese and stainless steels

: BS 970 : Part 1

Stainless steel tubes suitable for threading in accordance with BS 21

: BS 6362

12.4.3 Aluminium

(a) Aluminium for traffic signs shall be H 30 TF and shall comply with the following:

Wrought aluminium and aluminium alloys for general engineering purposes (i) plate, sheet and strip

(ii) drawn tube (iii) bars, extruded round tubes and sections

: : :

BS 1470 BS 1471 BS 1474

(b) Aluminium shall be anodised to Grade AA 25 in accordance with BS 1615. (c) Aluminium sheet shall be free from twisting, warping and buckling and the

surfaces shall be free from blemishes and other defects.


12.4.4 Bolts, nuts, screws, washers and rivets

(a) Bolts, nuts, screws, washers and rivets for traffic signs shall comply with the following:

ISO metric black hexagon bolts, screws and nuts : BS 4190

ISO metric black cup and countersunk head bolts and screws with hexagon nuts

: BS 4933

Metal washers for general engineering purposes : BS 4320

Rivets for general engineering purposes : BS 4620

Wrought aluminium and aluminium alloys for general engineering purposes - rivet, bolt and screw stock

: BS 1473

General inspection and testing procedures and specific requirements for carbon, carbon manganese and stainless steels

: BS 970 : Part 1

(b) The length of bolts shall be such that after assembly the threaded portion of

each bolt projects through the nut by at least one thread and by not more than four threads.

(c) Rag and indented bolts shall comply with BS 1494 : Part 2. Expansion bolts

and resin bonded bolts shall be a proprietary type reviewed without objection by the Project Manager and shall be capable of withstanding the design loading.

(d) Galvanised bolts, nuts, screws, washers and rivets shall be used with traffic

signs secured to galvanised pedestrian guard-railing. Aluminium materials shall be insulated from ferrous materials including any coated ferrous materials by a non-conductive insulator at least 2 mm thick of a type reviewed without objection by the Project Manager.

12.4.5 Materials for faces of traffic signs

(a) Retroreflective sheeting shall be Class 1 material complying with BS 873 : Part 6, Tables 1 and 2.

(b) Non-retroreflective sheeting shall comply with BS 873 : Part 6. (c) Plastic sheeting shall be a proprietary type reviewed without objection by the

Project Manager. (d) All materials and finishes shall be mutually compatible.


12.4.6 Hot applied thermoplastic material

(a) Hot applied thermoplastic material shall comply with BS 3262 : Part 1 except that:

(i) the softening point measured in accordance with BS 3262 : Part 1,

Appendix E, shall not be less than 85°C; and

(ii) the flow resistance shall be such that a cone made and tested in accordance with BS 3262 : Part 1 shall not slump by more than 25% after 48 hours at 40°C ±2°C.

(b) Solid glass beads shall be included in the supplied mixture of hot applied

thermoplastic material.

(c) Binder for thermoplastic material shall be synthetic hydrocarbon resin or natural resin based as stated in the Contract.

12.4.7 Cold applied preformed material

(a) Cold applied preformed material for road markings shall be a proprietary type reviewed without objection by the Project Manager

(b) Solid glass beads shall be applied to cold applied preformed material at the

place of manufacture.

12.4.8 Paint for road markings

Paint for road markings shall comply with BS 6044. 12.4.9 Solid glass beads

Solid glass beads shall comply with BS 6088, Class B. 12.4.10 Delivery and storage of thermoplastic material

Hot applied thermoplastic material shall be delivered and stored in accordance with BS 3262 : Part 1, Clauses 9 and 10 and the manufacturer's recommendations.

12.4.11 Road studs

(a) Road studs shall comply with the Road Traffic Ordinance, Cap 374 and its subsidiary legislation.

(b) Road studs shall be a proprietary type reviewed without objection by the

Project Manager. (c) Permanent reflecting road studs to be used as lane line markers on dual

carriageway trunk roads and primary distributor roads shall be a type to which traffic cylinders of a type reviewed without objection by the Project Manager can be attached. The method of attachment shall be such that the traffic cylinder can be easily detached from the road stud.


(d) Temporary reflecting road studs to be used as markers for temporary traffic routes shall be yellow.

12.4.12 Bitumen grout

(a) Bitumen grout for road studs shall consist of bitumen and filler. The bitumen content shall be 25% to 30% of the total mass.

(b) Bitumen shall be tropical grade filled bitumen, oxidised grade R 85/25. (c) Filler shall be hydrated lime; the percentage by mass of hydrated lime passing

a 75 m BS test sieve shall be at least 85%.　 (d) The properties of bitumen grout for road studs shall comply with the following

requirements:

(i) the penetration at 25°C shall be 12±4;

(ii) the softening point shall be 105°C ± 5°C; and

(iii) the specific gravity shall not exceed 1.80. 12.5 SUBMISSIONS 12.5.1 Particulars of traffic signs

(a) The following particulars of the proposed traffic signs shall be submitted to the Project Manager for review:

(i) name of manufacturer; and

(ii) details of materials and finishes to be used in the manufacture of the

signs. 12.5.2 Particulars of road markings

The following particulars of the proposed materials for road markings shall be submitted to the Project Manager for review:-

(a) certificates for thermoplastic material, paint and solid glass beads showing the

manufacturer's name, the date and place of manufacture and showing that the material complies with the requirements stated in the Contract and including results of tests for softening point and flow resistance of thermoplastic material.


12.6 WORKMANSHIP 12.6.1 Posts for traffic signs

(a) Posts for beacons at zebra crossings shall be painted with alternate black and white stripes. Other posts shall be painted grey in accordance with BS 5252F, Code 18B19 or shall be galvanized in accordance with BS 729.

(b) Galvanised areas affected by cutting and drilling shall be treated using a

method reviewed without objection by the Project Manager. (c) Posts other than posts supporting an external luminaire shall not protrude

above the top of signs. The length of posts supporting external luminaries protruding above the top of signs shall be as short as practicable.

12.6.2 Backing plates for traffic signs

(a) Backing plates for traffic signs shall be fabricated from 3 mm aluminium sheet. Backing plates for traffic signs not exceeding 1200 mm high x 2400 mm wide shall be fabricated from a single sheet. If more than one sheet is used, the number of sheets shall be kept to a minimum; the separate sheets shall be rectangular and shall be approximately the same size.

(b) Holes in backing plates shall be drilled before the plate is painted and before

retroreflective or non-retroreflective sheeting is applied. 12.6.3 Spill screens for traffic signs

(a) Top and bottom light spill screens shall be fabricated from the same material as the backing plate. The spill screens shall extend for the complete width of the backing plate and the corners shall be cut to the same radius as the corners of the backing plate.

(b) Spill screens shall be considered as part of the backing plate and stiffeners

and mountings shall be designed to accommodate the combined size. 12.6.4 Faces for traffic signs

(a) Faces for traffic signs shall be formed using retroreflective or non-retroreflective plastic sheeting. Unless otherwise permitted by the Project Manager, a single piece of sheeting shall be used. If more than one sheet is used, the number of sheets shall be kept to a minimum. Sheeting shall be fixed in accordance with the manufacturer's recommendations.

(b) Materials for faces of traffic signs, including the background, letters,

characters, numerals, symbols and borders, shall be matched for colour in accordance with the sheeting manufacturer's recommendations at the time of fabrication to provide a uniform appearance by day and by night.

(c) Letters, characters, numerals, symbols and borders shall be clear cut and

sharp-edged and shall have no cracks. (d) Sheeting material, including letters, characters, numerals, symbols and

borders shall be fully fixed using adhesive; there shall be no air bubbles, creases, cracks or other blemishes.


12.6.5 Lacquer coatings

Lacquer coatings to faces for traffic signs shall be uniform and continuous and shall be applied at the time of manufacture of the face.

12.6.6 Painting to faces for traffic signs

(a) Faces of traffic signs to which a painted or stoved finish is to be applied shall be thoroughly cleaned and pre-treated before painting and stoving.

(b) Pre-treatment shall be by anodising or by using an etching primer. (c) At least one undercoat and at least one finishing coat of paint shall be applied

and stoved to a thickness of between 0.0315 mm and 0.0375 mm of enamel over a minimum thickness of 0.025 mm of primer. If light colours are to be applied over dark colours, at least two coats of the light colour shall be applied. The final surface shall have a uniform thickness and an egg-shell flat finish and shall be smooth and free from defects.

(d) The colours of the finished coating shall be uniform. The colours, including

white, shall comply with the chromaticity co-ordinates of BS 873 : Part 6, Table 4 and, for comparative purposes, shall comply with the following gloss paint colours in accordance with BS 381C:

(i) red : No. 537 - signal red;

(ii) orange : No. 557 - light orange;

(iii) yellow : No. 355 - lemon yellow;

(iv) blue : No. 109 - middle blue; and

(v) green : No. 225 - light brunswick green.

(e) Parts of faces coloured black shall be non-retroreflective and shall have a

luminance factor not exceeding 0.05 as measured in accordance with BS 873 : Part 6.

12.6.7 Construction and assembly of traffic signs

(a) Fittings for traffic signs shall be non-corrodible material reviewed without

objection by the Project Manager. (b) Joints for framework and stiffeners which are not an integral part of the

backing plate shall be welded or joined using brackets, nuts, bolts and washers.

(c) Materials for rivets and other fixings for joining backing plates to framework

and stiffeners shall be compatible with the materials to be joined. The spacing of rivets and other fixings shall be uniform; the spacing shall not exceed 150 mm around the outside edge of sheets and shall not exceed 300 mm on cross braces.


(d) An additional washer of neoprene or nylon shall be used to protect the faces of traffic signs from metal nuts, bolts, washers and screws.

(e) Backing plates shall be connected to posts by a method reviewed without

objection by the Project Manager. Banding systems shall be stainless steel. Drilling of holes in ferrous components shall be completed before finishes are applied.

(f) A lacquer coating shall be applied to the edges of holes drilled in plates with

plastic sheeting immediately before rivets and bolts are inserted. The surfaces of rivets and bolts on the faces of traffic signs shall be covered with a material coloured to match the part of the face with which it is in contact.

(g) Fixings for traffic signs erected on road lighting columns shall be compatible

with the column cross section. Columns shall not be drilled. 12.6.8 Covering of traffic signs

(a) Traffic signs which are to be blanked out shall be covered by the following methods:

(i) Plate signs shall be covered using a 1.5 mm thick sheet which is

compatible with the material in the sign.

(ii) Plate signs which are to be blanked out for a period not exceeding one year shall alternatively be covered using a self-adhesive plastic film.

(iii) Other signs shall be covered using a loose cover sheet of material

reviewed without objection by the Project Manager.

(b) Cover sheets shall be fixed using 5 mm diameter stainless steel bolts, washers and nuts or non-ferrous rivets at spacings not exceeding 600 mm. Bolts shall pass through 5 mm x 12 mm diameter plastic distance pieces between the face of the sign and the cover plate. Holes which remain on the finished face of the sign shall be filled using blocked rivets; the face of the rivets shall be coloured by a method reviewed without objection by the Project Manager.

(c) Self-adhesive plastic film shall be compatible with the material in the face of

the sign and shall be fixed and removed in accordance with the manufacturer's recommendations.

(d) Loose covers shall be securely fastened to the back of the sign. Tape or

other adhesive material shall not be applied to the faces of signs. (e) Coverings to traffic signs shall be sufficiently opaque to prevent reflection from

the covered sign and shall not be removed until the Project Manager so directs.

(f) The faces of traffic signs which have been erected and which do not relate

either wholly or in part to the traffic situation which applies at that time shall be blanked out as stated in this Clause.


12.6.9 Preparation of surfaces for Road markings

(a) Road markings shall not be laid over loose detritus, mud or similar extraneous matter. Oil and grease shall be removed from the surface of carriageways on which road markings will be laid.

(b) Curing compound shall be removed from the surface of new concrete

carriageways on which road markings will be laid, by wire brushing or by other methods reviewed without objection by the Project Manager.

(c) Existing road markings which are to be replaced by a different type of material

shall be removed by high pressure water jetting, shot blasting or rotary grinding; the existing markings shall not be masked using black paint or similar methods.

(d) Existing road markings which are to be renewed using a similar type of

material shall be roughened by a method reviewed without objection by the Project Manager until the thickness of the existing material is reduced by approximately 50%.

(e) A tack coat shall be applied to the surface of concrete carriageways before

hot thermoplastic material is laid. The tack coat shall be compatible with the road marking material and shall be applied in accordance with the manufacturer's recommendations.

(f) Rotary grinding machines shall not be used to remove or roughen existing

road markings within 100 mm of longitudinal or transverse joints on concrete carriageways.

12.6.10 Laying hot applied thermoplastic material

(a) Hot applied thermoplastic material shall be prepared and laid in accordance with BS 3262 : Part 3, Clauses 4 and 5. The material shall not be laid when the surface of the carriageway is wet, or the air ambient temperature in the shade is less than 10°C.

(b) Hot applied thermoplastic material shall be laid by machine or by screeding

methods. The machine or apparatus shall be capable of producing a marking to a uniform thickness and width; the marking shall have clean edges and shall be free from streaks and blisters.

(c) The thickness of road markings, not including surface applied solid glass

beads, shall comply with the following:

(i) screed markings : 4 mm;

(ii) sprayed lines other than yellow edge lines : ≥ 1.5 mm; and

(iii) sprayed yellow edge lines : ≥ 0.8 mm.

The thickness shall be measured in accordance with BS 3262 : Part 3, Appendix B.

(d) Traffic shall not be permitted to run over road markings until they are dry and

set.


12.6.11 Laying cold applied preformed material

(a) Cold applied preformed material shall be laid in accordance with the manufacturer's recommendations. The material shall not be laid when the surface of the carriageway is wet.

(b) The thickness of road markings shall be at least 1.5 mm. (c) Traffic shall not be permitted to run over road markings until they are dry and

set. 12.6.12 Use of road marking paint

Road marking paint shall not be used other than for temporary road markings. 12.6.13 Reflectorisation

Solid glass beads shall be applied to the surface of hot applied thermoplastic material and road marking paint immediately after the material or paint has been applied, to enhance the reflectivity of the surface. The solid glass beads shall be uniformly applied by a mechanical method at a rate of between 400 g/m² and 500 g/m².

12.6.14 Temporary road markings

(a) Temporary road markings shall be used at locations directed by the Project Manager. Cold applied preformed material shall be used for temporary road markings which are to be removed.

(b) Temporary road markings shall be disposed of by the Contractor after

removal. All traces of tape shall be removed from the surface of the carriageway and existing permanent road markings shall be made good such that it is safe to allow traffic to use the road.

12.6.15 Skid resistance level

The skid resistance level of road markings measured in accordance with BS 3262 : Part 1 shall be at least 45.

12.6.16 Tolerances: road markings

The lengths, thicknesses and widths of hot applied thermoplastic material road markings shall comply with the following requirements:

(a) The thickness of screed markings shall be within 1 mm of the specified

thickness. (b) The length and width of screed markings and sprayed lines shall be within

+10%, -5% of the specified dimension.


12.6.17 Installation of road studs

(a) Road studs shall be installed in accordance with the manufacturer's recommendations.

(b) Depressible road studs shall be installed using bitumen grout. (c) Road studs shall not be installed on concrete carriageways until the concrete

has reached the specified grade strength. (d) Surfaces to which bonded road studs are to be fixed shall be clean and all

dust, grease and other deleterious material shall be removed immediately before the studs are installed.

12.7 INSPECTION, TESTING AND COMMISSIONING 12.7.1 Testing : traffic signs

(a) The number of traffic signs to be tested shall be as stated in the Contract or as directed by the Project Manager.

(b) The number and type of tests to be carried out on the traffic signs shall be as

stated in the Contract or as directed by the Project Manager. (c) Testing shall be carried out in such a manner that the traffic sign will not be

damaged. (d) Testing shall be carried out by the Contractor at a laboratory reviewed without

objection by the Project Manager. 12.7.2 Compliance criteria : traffic signs

The compliance criteria for testing traffic signs shall be in accordance with BS 873:Part 1.

General Materials & Workmanship Specification 1/10 January 2011 Issue No. 5, Volume 1 - Civil & Structural Works Section 13 – Work for E & M Installations

SECTION 13 WORK FOR ELECTRICAL AND MECHANICAL INSTALLATIONS

13.1 GENERAL

13.1.1 General requirements

(a) The works and materials specified in the following sub-clauses shall comply with the Sections stated, unless otherwise stated in this Section.

(i) Earthworks shall comply with Section 7.

(ii) Structural steelwork shall comply with Section 22.

(b) For the purposes of this Section 13 of the General Materials and

Workmanship Specification, the term electrical and mechanical work shall consist of all mechanical and electrical services, systems and equipment including but not limited to the following :

(i) heating, ventilation and air-conditioning systems; (ii) refrigeration systems;

(iii) gas systems;

(iv) electrically powered systems;

(v) high and low voltage electrical distribution systems;

(vi) lighting systems;

(vii) lightning protection systems;

(viii) earthing systems;

(ix) fire services systems;

(x) hydraulic, plumbing and drainage systems;

(xi) video, data and voice communication systems;

(xii) control, supervisory and monitoring systems; (xiii) baggage handling systems;

(xiv) utility services;

(xv) lifts, escalators and moving walkway systems; and

(xvi) automatic people movement systems.


13.1.2 Concealed electrical conduit system

Concealed electrical conduit system is an electrical conduit system, including all bends, couplers, bushes, saddles, boxes, covers, plugs, draw wires and other conduit fittings, which is cast into concrete or fixed in chases in brickwork with a minimum cover of 20 mm or which is laid directly in the ground.

13.1.3 Requirements for electrical and mechanical installations

(a) The principle requirements for electrical and mechanical installations will be as shown on the Employer's Drawings. Confirmation of these provisions and identification of any other requirements, including holes, sleeves and recesses, shall be carried out in accordance with the requirements of the Section 11 of the General Specification.

(b) Where holes, sleeves and recesses are to be provided in concrete structures

they shall be formed prior to placing of concrete and shall not be cut through hardened concrete.

(c) Where pipework, cables, cable trunking or trays, ducts or fire dampers or

other elements of electrical and mechanical system pass through structural or non-structural elements, the requirements of Sections 44-60 of the General Materials and Workmanship Specification shall apply.

(d) Holes, sleeves and recesses in internal floors, stairways and platforms shall

be protected with temporary covers until the electrical and mechanical installation starts. Holes, sleeves and recesses in roofs, external walls and external floors shall be sealed with watertight temporary covers reviewed without objection by the Project Manager until the electrical and mechanical installation starts.

13.2 MATERIALS 13.2.1 Electrical conduits and fittings

(a) Electrical conduits and fittings shall comply with BS 4568 : Parts 1 and 2 and shall have Class 4 heavy protection inside and outside. Conduits shall be heavy gauge with screw-end construction in steel and shall have an external diameter of at least 20 mm; conduits shall be longitudinally welded.

(b) Metal boxes for enclosing electrical accessories shall comply with BS 4662

and shall have heavy protection inside and outside; the boxes shall be of preferred sizes and shall be 35 mm or 47 mm deep as appropriate. Circular ceiling boxes of deep pattern shall comply with BS 4568 : Part 2 and shall have Class 4 heavy protection inside and outside; the boxes shall be at least 60 mm deep internally.

(c) Circular boxes, dome covers and hook covers shall be cast iron. Bushes and

plugs shall be brass.


13.2.2 Cable ducts and fittings

(a) UPVC cable ducts for installation above ground or for casting into concrete shall be Class 0 UPVC pipes complying with BS 3506. Cable ducts for installation below ground shall be Class B UPVC pipes complying with BS 3506. For road lighting systems, the colour of the underground UPVC pipe shall be purple.

(b) Joints and fittings for use with UPVC cable ducts shall comply with BS 4346 :

Part 1 and BS 4346 : Part 2. Solvent cement for UPVC pipes and fittings shall comply with BS 4346 : Part 3.

(c) Steel cable ducts shall be steel tubes complying with BS 1387, medium

series, screwed and socketed tubes and shall have screwed sockets suitable for screwing to BS 21, Table 2 pipe threads. The tubes, sockets, clamps and saddles for ducts shall be galvanized in accordance with BS 729.

13.2.3 Paint for conduit and duct systems

(a) Bituminous paint for steel conduits and steel cable ducts shall comply with BS 3416, type 1.

(b) Anti-rust paint for concealed electrical conduit systems shall be a proprietary

type reviewed without objection by the Project Manager. (c) Zinc chromate primer for cable duct systems shall comply with BS 4652. (d) Galvanizing paint for cable duct systems shall be a proprietary type reviewed

without objection by the Project Manager. 13.2.4 Fire barriers

Internal fire barriers shall be a type offering adequate fire resistance for the application. The material shall be reviewed without objection by the Project Manager in compliance with Fire Services Department requirements and shall be resistant to fire, smoke, gas and water.

13.2.5 Cement grout for electrical and mechanical installations

(a) Materials for grout shall comply with Section 20. (b) The different types of cement grout for electrical and mechanical installations

shall consist of ordinary Portland cement, sand and PFA in the proportions by mass stated in Table 13.1 together with the minimum amount of water necessary to achieve a consistency suitable for completely filling the voids. The mix shall contain a non-shrink admixture.


Table 13.1: Mix Proportions of Cement Gout

Type Mix proportions by mass Cement Sand PFA

G1 1 - - G2 1 3 - G3 1 10 - G4 1 - 7

13.2.6 Cables

(a) PVC insulated cables shall be single core of copper conductors, 450/750V grade and flame retardant PVC insulation to BS 6004.

(b) The current carrying capacity shall be in accordance with IEE Wiring

Regulations. Minimum size of cables shall be as follows unless other specified:

Lighting 2.5 sq mm Control 1.5 sq mm

(c) All wiring shall be carried out on the loop-in system and the wires shall be

drawn into the conduits after the whole of this installation has been completed. No joints or connectors will be allowed in any such cable, except that connectors may be used in accessible positions with lighting fittings.

(d) All PVC insulated cables shall be installed in galvanized conduit. (e) All PVC/SWA/PVC cables shall be installed as shown on the Employer’s

Drawings and terminated in brass glands fitted with amour clamps. 13.3 WORKMANSHIP 13.3.1 Construction of conduit systems

(a) Concealed electrical conduit systems which are shown diagrammatically in the Contract shall be constructed as stated in Clause 13.3.1(b) to (g).

(b) Concealed electrical conduit systems shall be mechanically continuous and

where metallic conduits are used they shall also be electrically continuous and effectively earthed.

(c) Principal conduit runs shall be either vertical or horizontal. Tee pieces and

elbows, including those with provision for inspection, shall not be used.

(d) Joints shall be made using coupler units into which the ends of the conduits shall be inserted and tightened. Running couplings shall not be used unless permitted by the Project Manager; if permitted, the couplings shall be made by screwing each of the conduits half way into the coupler with a hexagonal lock nut against each end of the coupler.


(e) Adaptable boxes shall be provided at:

(i) every second bend;

(ii) after a bend and a straight run of 10 m or less; and

(iii) every 15 m in straight runs.

(f) Adaptable boxes for conduits installed in floor screeds shall have the lids set flush with the adjacent floor; the boxes shall be covered with the same material as the remainder of the floor and shall remain accessible at all times.

(g) The clearance between conduits entering adaptable boxes and between

adjacent or parallel conduits shall be at least the nominal maximum coarse aggregate size of the concrete plus 5 mm.

13.3.2 Installation of conduit systems

(a) Concealed electrical conduit systems shall be arranged and installed in accordance with best trade practice and in such a manner that all cables can be drawn with ease and without damage.

(b) All conduit systems shall be installed fully in accordance with the

requirements of the current IEE Wiring Regulation. (c) Bends in concealed electrical conduit systems shall be formed by using

proprietary bending equipment of a type reviewed without objection by the Project Manager; connections and other work shall be carried out using purpose made equipment.

(d) Conduits shall not be bent by more than 90° and the internal radius at bends

shall be at least 2.5 times the external diameter of the conduit. Conduits shall not be flattened at bends.

(e) Burrs and sharp edges shall be removed from the ends of conduits before

installation. (f) Concealed electrical conduit systems which are to be cast into concrete shall

be fastened to the reinforcement with tying wire of the same type used for the reinforcement. The conduit systems shall not be positioned between the reinforcement and the outside face of the concrete.

(g) Conduit boxes shall be of a compatible size and shall have a single extension

ring of the required depth if the plaster finish exceeds 13 mm thick; multiple extension rings shall not be used.

13.3.3 Terminations of conduit systems

Screw fitting couplers shall be provided at each end of conduits which terminate in distribution boards, busbar chambers, motor starters, cable ducts, boxes or similar termination points. The item at which the conduit terminates shall be drilled with an unthreaded clearance hole to receive a brass male bush; the bush shall be screwed into the coupler from the inside of the item in such a manner that the surface of the item is gripped between the coupler and the bush. The threads shall be at least half the length of the coupler.


13.3.4 Protection of conduit systems

(a) Concealed electrical conduit systems shall have special arrangements designed by the Contractor to permit movement of conduits to take place on each side of movement joints in structures. A separate circuit protective conductor shall be installed to maintain effective electrical continuity across the joint. The protective conductor shall have a cross-sectional area rated to suit the largest live conductor to be drawn into the conduit.

(b) Steel conduit systems laid in contact with or adjacent to other metal work shall

have efficient and permanent metallic connection made between the conduit and the metal work.

(c) Underground steel conduits and conduits in contact with soil shall be painted

with two coats of bituminous paint before installation. (d) Exposed threads and damage to protective coatings of conduit systems shall

be painted with two coats of anti-rust paint. (e) Conduits shall be laid in such a manner that accumulation of condensed

moisture in the conduit system is prevented; measures shall be taken to prevent water from entering the system.

(f) Water, moisture and deleterious material shall be prevented from entering

permanent and temporary terminations in concealed electrical conduit systems, including conduit boxes, by using conduit stopping plugs of a type reviewed without objection by the Project Manager; paper or rags shall not be used.

13.3.5 Cleaning of conduit systems

After installation, concealed electrical conduit systems shall be swabbed out with draw-in tapes and absorbent cloth of a type reviewed without objection by the Project Manager; all obstructions shall be removed and draw wires shall be installed. After cleaning, exposed conduit ends shall be sealed as stated in Clause 13.3.4(f).

13.3.6 Installation of cable duct systems

(a) Changes in direction in cable duct systems shall be constructed in such a manner that the cables in the duct will have radii of curvature of at least 800 mm. Ducts entering draw-in pits shall be on the same horizontal plane as the draw-in pit.

(b) UPVC cable ducts shall be jointed in accordance with the manufacturer's

recommendations. (c) Steel cable ducts shall be jointed using screwed galvanized sockets and spun

yarn such that the jointed pipes abut; the threads shall be painted with two coats of bituminous paint. Internal rags and burrs shall be removed to provide a smooth bore through joints in the cable duct system.

(d) Surface mounted cable ducts shall be secured by galvanised steel clamps or

saddles at spacings not exceeding 3 m.


(e) Ducts laid in the ground shall be kept at least 150 mm clear of gas and water mains and all other utility services. In the case of any type of electricity supply the following minimum separating distance shall be provided:-

(i) High Voltage single core cables (exceeding 650 Volts) .............. 450 mm

(ii) High Voltage multi-core cables (exceeding 650 Volts) ................ 300 mm

In cases where it is not possible to provide the required clearance, a layer of concrete not less than 50 mm thick shall be provided between the duct and the electricity supply cable.

(iii) Low and Medium Voltage cables (not exceeding 650 Volts) ....... 150 mm

where the duct and electricity supply cable cross with minimum separation a layer of concrete 50 mm thick shall be provided.

(f) To ensure the correct alignment of ducts, a wooden mandrel shall be drawn

forward as the ducts are laid. 13.3.7 Protection of cable duct systems

(a) After jointing, exposed bare metal in cable duct systems shall be cleaned and painted with two coats of zinc chromate primer and two coats of galvanizing paint.

(b) Surface mounted galvanized steel cable ducts shall be cleaned and painted

after fittings and jointing have been completed. 13.3.8 Cleaning of cable duct systems

After jointing, cable duct systems shall be cleaned internally by scrubbing with a cylindrical brush of a type reviewed without objection by the Project Manager. The ends of ducts, including ends of ducts in draw-in pits and spare ducts, shall be fitted with tapered hardwood plugs to prevent water, moisture and deleterious material from entering the system and a 6 mm diameter nylon draw line shall be installed. The plugs shall be centrally drilled for the draw line and the draw line shall be secured by a knot tied on the outer face of the plug to leave at least 1500 mm of surplus line at each plug.

13.3.9 Electrical earthing systems

(a) Pits and trenches for electrical earthing systems shall be excavated at

positions and at the times directed by the Project Manager. (b) After the electrical earthing systems have been installed fill material shall be

deposited and compacted in the pits and trenches to a depth of 300 mm above the electrical earthing system. Fill material shall be sand or fine fill material which has been selected from the excavated material, and which is free from stones retained on a 20 mm BS test sieve. Fill material shall be compacted by handrammers in a manner reviewed without objection by the Project Manager.


(c) The Contractor shall supply and install 1 no. 16mm diameter copper earth rod, with sufficient length for the pillar box, to ensure earth continuity complete with concrete lined pits with removable lids to enable access to the connection between the earthing electrode and earth lead to be obtained. The earth pits shall be at ground level sited as close as possible to the pillar box and the earth lead shall be 25 x 3mm copper tape.

13.3.10 Grouting for electrical and mechanical installations

(a) Grouting to structural steelwork, machine bases, crane rails, electrical and mechanical equipment and other electrical and mechanical installations shall comply with the requirements stated in Clause 13.3.10(b) to (g).

(b) The Contractor shall notify the Project Manager before items or equipment are

grouted. (c) Concrete surfaces shall be scabbled to remove laitance and loose material

and to expose the aggregate before the item or equipment is installed in position.

(d) The voids to be grouted shall be cleaned and thoroughly wetted immediately

before grouting. Excess water shall be removed by using a compressed air jet.

(e) Grout shall be mixed and placed by methods reviewed without objection by

the Project Manager. (f) If grouting is to be carried out in two operations, holding down bolts shall be

grouted into preformed pockets and sufficient time shall be allowed for the grout to cure and for the bolts to be tensioned before the remaining voids are grouted.

(g) Exposed grout surfaces shall have a uniform, dense and smooth surface free

from trowel marks and which is produced by steel trowelling the surface under firm pressure. The exposed surfaces shall be cured by either:

(i) using a liquid curing compound applied to the surface by a low-pressure

spray until a continuous visible covering is achieved; or

(ii) covering the surface with hessian or sacking; the hessian or sacking shall be lapped and securely held in position and shall be kept damp for at least 4 days.

13.3.11 Completion of work for electrical and mechanical installations

(a) Unless otherwise stated in the Contract work shall be completed to the conditions stated in Clause 13.3.11(b) to (g) inclusive before structures are made available to Other Contractors for electrical and mechanical installations.

(b) Structures shall be clean, dry and free from dust. Work which will produce

large quantities of dust shall be complete.


(c) Holes and recesses, concealed electrical conduit systems and cable duct systems required for the installation shall be complete. Concrete surfaces on which items and equipment are to be installed shall be scabbled.

(d) Plinths, trenches, louvres, openings and similar work shall be complete and

shall have hardened sufficiently to allow the installation to proceed. (e) Floors and slabs shall be complete to the specified finishes except that floor

tiles shall not be laid until after the installation is complete. (f) Plant rooms shall be complete, including fixtures and fittings, to a secure and

weatherproof condition. Two sets of door keys for each plant room shall be provided for the Project Manager.

(g) Paintwork and similar finishes in plant rooms shall be complete to undercoat

level; final coats shall not be applied until after the installation is complete. 13.3.12 Protection of work for electrical and mechanical installations

(a) Structures in which electrical and mechanical installations are being carried out shall be maintained in a clean, dry condition, free from dust, during the installation.

(b) The dust level in plant rooms shall be kept to a minimum by using industrial

dust extractors of a type reviewed without objection by the Project Manager during and after the installation. Temporary screens shall be installed to separate dust-affected areas from the installations or temporary covers shall be installed around the installation.

13.4 INSPECTION, TESTING AND COMMISSIONING 13.4.1 Inspection of work for electrical and mechanical installations

(a) The Contractor shall allow the Project Manager to inspect the following work for electrical and mechanical installations:

(i) completed concealed electrical conduit systems, cable duct systems,

electrical earthing systems and items and equipment which are to be grouted or covered up;

(ii) items and equipment which are to be tested; and

(iii) structures which are to be made available for electrical and mechanical

installations.

(b) The Contractor shall notify the Project Manager three days, before work is covered up, tested or made available.


13.4.2 Testing: earthing continuity

(a) Concealed electrical conduit systems shall be tested to determine the earthing continuity. The system shall be tested:

(i) before the system is cast in concrete or covered up;

(ii) after the system is cast in concrete or covered up; and

(iii) after electrical wiring which is installed by the Contractor is complete.

(b) The method of testing shall be in accordance with the 16th Edition of IEE

Wiring Regulations issued by the Institution of Electrical Engineers. (c) The results of tests for earthing continuity shall comply with the 16th Edition of

IEE Wiring Regulations issued by the Institution of Electrical Engineers. 13.4.3 Testing: load tests on beams and joists

(a) Load tests shall be carried out on lifting beams, rolled steel joists, lifting hooks, eyes and anchorage points which are installed by the Contractor for electrical and mechanical work or other Permanent Works.

(b) Testing shall be carried out by an independent testing authority reviewed

without objection by the Project Manager and by using methods reviewed without objection by the Project Manager.

(c) A certificate showing the results of the load tests and signed by the testing

authority shall be submitted to the Project Manager for review without objection within 7 days of the test.

(d) The results of tests on lifting beams, rolled steel joists, lifting hooks, eyes and

anchorage points shall comply with the Factories and Industrial Undertakings (Lifting Appliances and Lifting Gear) Regulations, 1978 issued by the Labour Department.

General Materials & Workmanship Specification 1/23 January 2011 Issue No. 5, Volume 1 - Civil & Structural Works Section 14 – Water Supply Pipeworks

SECTION 14 WATER SUPPLY PIPEWORKS 14.1 GENERAL 14.1.1 General requirements

The Permanent Works and materials specified below shall comply with the Sections stated, unless otherwise stated in this Section.

(a) Drainage works shall comply with Section 6. (b) Earthworks shall comply with Section 7. (c) Formwork and finishes to concrete shall comply with Section 18. (d) Concrete shall comply with Section 20.

14.2 DEFINITIONS AND ABBREVIATIONS 14.2.1 Fitting

Fitting is a component fitted to a pipe for jointing or connecting or for changing the direction or bore of a pipe.

14.2.2 Flexible joint

Flexible joint is a connection between pipes and fittings which provides angular deflection or axial movement or a combination of both in service without impairing the efficiency of the connection.

14.2.3 Mechanical joint

Mechanical joint is a flexible joint in which an elastomeric joint ring is located in the socket and the joint sealed by applying pressure to the joint ring by means of a gland bolted to the socket.

14.2.4 Nominal size

Nominal size is a numerical designation of size which is common to all components in a pipework system. The nominal size is stated as a convenient round number in millimetres and is related to, but not normally the same as, the actual internal diameter of the pipework; dn designates the nominal size of tees and tapers which are less than DN.

14.2.5 Push-in joint

Push-in joint is a flexible joint in which an elastomeric joint ring is located in the socket and the joint is effected by entering the spigot through the joint ring into the socket.


14.2.6 Special fitting

Special fitting is a fitting which is made from a manipulated or fabricated pipe.

14.2.7 Thin walled pipe

Thin walled pipe is a pipe, including pipes of DN 1200 or greater, which has a ratio of nominal size to wall thickness, excluding linings and coatings, exceeding 125.

14.2.8 Nominal outside diameter of a polyethylene pipe

Nominal outside diameter of a polyethylene pipe shall mean the minimum mean outside diameter of the pipe as described in Clause 3.1 of ISO 161-1.

14.2.9 Nominal wall thickness of a polyethylene pipe

Nominal wall thickness of a polyethylene pipe shall mean the minimum wall thickness of the pipe as described in Clause 3.4.5 of BS ISO 11922-1.

14.2.10 Standard Dimension Ratio

The Standard Dimension Ratio (SDR) of a polyethylene pipe shall mean the ratio of its nominal outside diameter to its nominal wall thickness as described in Clause 3.8 of ISO 161-1.

14.2.11 WIS

WIS shall mean the Water Industry Specification produced and published by WRC. 14.3 MATERIALS 14.3.1 Materials for water supply pipeworks

Materials for water supply pipeworks for potable water shall be non-toxic, shall not promote microbial growth and shall not impart a taste, odour, cloudiness or discolouration to the water after disinfection and washing out of the pipelines as stated in Clause 14.6.8. Water supply pipework shall be either ductile iron or polyethylene unless otherwise reviewed without objection by the Project Manager.

14.3.2 DI pipes and fittings

(a) DI pipes and fittings shall comply with BS 4772. Pipes and fittings other than collars, caps and blank flanges shall be lined internally with cement mortar in accordance with BS 4772, Clause 3.2. Linings shall be made with sulphate-resisting Portland cement complying with BS 4027.


(b) Pipes shall be externally coated with metallic zinc in accordance with BS 4772, Clause 3.1. Fittings shall be externally coated with zinc rich paint in accordance with BS 4772, Clause 3.1.5(b). After zinc coating pipes and fittings shall be externally coated with a finishing coat of one of the following materials as stated in BS 4772, Clause 3.3:

(i) bitumen based hot applied coating material complying with

Clause 23.22 and BS 4147 : Type I, Grade C; or

(ii) bitumen based cold applied coating material complying with Clause 23.22 and BS 3416 : Type II.

14.3.3 Flanges

(a) DI flanges shall be cast-on or welded-on standard flanges complying with BS 4772.

14.3.4 Bolts and nuts

(a) Bolts and nuts for flanged joints shall comply with BS 4504 : Section 3.1, Section 6.

(b) Bolts and nuts shall be compatible with the type of joint and shall be obtained

from the same manufacturer as the joint. (c) Bolts shall be sufficiently long and shall be suitably threaded for jointing the

relevant flanges. 14.3.5 Elastomeric joint rings

Elastomeric joint rings for DI pipes and fittings shall comply with BS 4772, Clause 2.3.4. The dimensions of rings for use with flanged joints shall comply with BS 4865 : Part 1. The rings shall be compatible with the type of joint and shall be obtained from the same manufacturer as the joint.

14.3.6 Polyethylene Pipes

(a) Polyethylene pipes shall be either PE80 or PE100 grade pipes in accordance with Clauses 14.3.6 (b) to (h)

(b) PE80 pipes with nominal outside diameter from 20mm to 63mm inclusive and

PE100 pipes with nominal outside diameter from 90mm to 180mm inclusive shall conform to ISO 4427.

(c) PE80 and PE100 pipes shall have a SDR of 11 and have nominal pressure

rating as follows:

(i) PE80 – 12.5 bar (PN12.5); and (ii) PE100 – 16 bar (PN16).


(d) The colour for polyethylene pipes shall be blue within the range below:

Nominal Outside Diameter Colour Range 20mm – 63mm 18E51 to 18E53 of BS 4901 90mm – 180mm 20D44 to 20D45 or 20E53 to 20E56 of BS 5252

(e) The tolerance on the nominal outside diameter of polyethylene pipes shall be

in accordance with Grade B of BS ISO 11922-1. (f) The end of the pipe shall be cut cleanly and square to the axis of the pipe to

within the tolerances given below:

Nominal Outside Diameter Maximum Tolerance (mm) 90mm and below 2

125mm 3 180mm 4

(g) Standard length of polyethylene pipes supplied shall be 6 m. For pipes of

nominal outside diameter from 20 mm to 63 mm, 50 m coils may be specified. No reduction in the specified length shall be allowed unless reviewed without objection by the Project Manager.

(h) Melt flow rate of PE80 and PE100 pipes tested at a temperature of 190°C

under a nominal load of 5 kg shall be within the range of 0.2 g/10 min to 1.3 g/10 min.

14.3.7 Fittings for Polyethylene pipes

(a) All fittings for polyethylene pipes shall have a pressure rating the same as or

higher than the nominal pressure rating of the pipes. The fittings shall be supplied with complete set of accessories including insert, liners, joint rings, flange gaskets, studs, bolts and nuts, etc. whatever appropriate.

(b) The flanges of all fittings shall be constructed in such a way that they may be

attached to flanges designated PN16 whose dimensions conform to Table 9 of BS EN 1092-2. One complete set of bolts and nuts and one gasket shall be supplied with each flange of flanged fittings. The strength of bolts shall be Grade 4.8 and the strength of nuts shall be Grade 4 complying with BS 4190. The bolts and nuts shall be hot dip galvanized or have other protective coatings reviewed without objection by the Project Manager.

14.3.8 Polyethylene Electrofusion Fittings

(a) Polyethylene electrofusion fittings including couplers, reducers, socket ends

tees, caps and elbows, self tapping tee saddles and other electrofusion fittings shall comply with WIS 4-32-14. Polyethylene spigot fittings for electrofusion jointing including the spigot stub flange assembly shall comply with WIS 4-32-15. Stub flanges shall comply with WIS 4-24-01.

(b) Melt flow rate of PE80 and PE100 electrofusion fittings tested at a

temperature of 190°C under a nominal load of 5kg shall be within the range of 0.2 g/10 min to 1.3 g/10 min.


(c) Notwithstanding Clause 5.1.6 of WIS 4-32-14, the fittings shall be capable of being fused in the tropics.

(d) The design for fitting terminals and shrouds shall be similar to that stated in

Clause 5.2.3 of WIS 4-32-14. Other designs of terminals will only be considered if the Contractor can demonstrate that appropriate lead adaptor is readily available such that electrofusion of their fittings can be conducted using common electrofusion control units available in the market.

(e) Unless otherwise reviewed without objection by the Project Manager, all electrofusion fittings shall be blue in colour within the range as specified in Clause 14.3.6(d).

14.3.9 Compression Fittings for Polyethylene Pipes

(a) Compression fittings for polyethylene pipes in a range of nominal outside diameter 20 mm to 63 mm inclusive, shall be Class 1 end-load bearing fittings conforming to ISO 14236.

(b) Compression fittings with external and/or internal threads shall be compatible

with pipes and fittings threaded to BS 21. 14.3.10 Mechanical Fittings for Polyethylene Pipes

(a) Mechanical fittings for polyethylene pipes of nominal outside diameter 90 mm

and above shall be Type 1 fittings conforming to WIS 4-24-01. (b) Mechanical fittings shall be coated with a minimum thickness of 250 microns

of epoxy or plastic based coating complying with the performance requirement of WIS 4-52-01.

14.3.11 Markings on Polyethylene Pipes and Fittings

(a) Markings on the polyethylene pipes and fittings shall be in accordance with

the relevant Clauses in the ISO or WIS appropriate to the pipes and fittings supplied.

(b) Notwithstanding Clause 8 of ISO 4427, the pipes series in SDR shall be

marked on the pipes. (c) Notwithstanding Clause 10 of ISO 14236, the designation of the material

(PE80 or PE100) and the number “ISO 14236” shall also be marked on the compression fittings.

14.3.12 Anticorrosion tape

(a) Anticorrosion tape shall be a propriety type reviewed without objection by the Project Manager. The tape shall either be a petrolatum tape with fabric reinforcement or a bituminous tape with PVC backing. Petrolatum tape shall be used for valves, flanged joints, slip-on type couplings and flange adaptors of all sizes. Bituminous tape shall be used in buried or non-exposed condition for welded joints of steel pipe, repair of steel pipe sheathing and other applications as specified on the Employer’s Drawings.


(b) Anticorrosion tapes shall have a high resistance to cathodic disbondment, acids and alkalis. Colour of bituminous tape shall be black. Anticorrosion tapes shall have as a minimum the properties stated in Table 14.1.

(c) Primer and mastic filler for use with anticorrosion tape shall be compatible

with the tape and shall be a type recommended by the manufacturer of the tape and reviewed without objection by the Project Manager.

(d) Bituminous tapes shall be stored in a cool dry place away from the sun’s rays.

The tape shall be free of dirt or grit immediately prior to application.

Table 14.1: Properties of Anticorrosion Tape

Properties Petrolatum Tape Bituminous Tape Thickness of PVC backing (mm) - 0.75 Total thickness (mm) 1.1 1.65 Mass (kg/m2) 1.4 2.0 Tensile strength (N/mm) 4 10 Adhesion strength (180° peel)

Self Steel

0.5 0.5

2.5 2.5

Dielectric strength (2 layers) (kV) 15 30 Elongation (at break) (%) - 260

Temperature range (°C) Wrapping Service

-5 to +45 -5 to +45

+5 to +50 -20 to +75

14.3.13 Bituminous coatings

(a) Bituminous coatings shall comply with the following: (i) Bitumen based hot applied coating

material for protecting iron and steel including suitable primers where required

: BS 4147, Type I, Grade C

(ii) Black bitumen coating solutions for cold application : BS 3416, Type II.

(b) Bituminous coatings used for repairing joints and coatings shall be compatible

with the adjacent coating. (c) Bituminous coatings shall be made from petroleum or asphaltic bitumen.

14.3.14 Zinc-based paint

(a) Zinc-based paint shall be a proprietary type reviewed without objection by the Project Manager.

(b) Primers for zinc-based paint shall comply with BS 4652. (c) Rust inhibitor shall be a chemical agent which is capable of converting rust

into iron phosphate.


14.3.15 Joint filler and compressible padding

(a) Joint filler for joints in concrete bed, haunch and surround shall be a proprietary type reviewed without objection by the Project Manager and shall be a firm, compressible, single thickness, non-rotting filler. The thickness of the filler shall be as stated in Table 14.2.

(b) Compressible padding between pipes and supports shall be bitumen

damp-proof sheeting complying with BS 743.

Table 14.2: Joint Filler for Concrete Bed, Haunch and Surround

Nominal diameter of Pipe Thickness of joint filler (mm) less than 450 mm 18 450 mm – 1200 mm 36 exceeding 1200 mm 54



14.3.17 Extension keys

Extension keys and clamps for valves shall be Grade 43A steel complying with BS 4360 and shall be hot-dip galvanised in accordance with BS 729 after fabrication.

14.3.18 Transport, handling and storage of pipes, joints and fittings

(a) Pipes, joints and fittings for water supply pipeworks shall be transported, handled and stored in accordance with the manufacturers' recommendations and in a manner which will not result in damage or deformation to the pipes, joints and fittings or in contamination of the pipes, joints and fittings.

(b) Pipes, joints and fittings shall be protected from damage and damaged pipes,

joints and fittings shall not be used in the Permanent Works. Pipes, joints and fittings shall be securely packed and supported to prevent movement when being transported.

(c) Bolts and nuts shall be packed in sealed metal containers. (d) Elastomeric joint rings shall be packed in bags and lubricant for joints shall be

stored in sealed containers marked to identify the contents. The rings and lubricant shall be protected from exposure to conditions which may affect the material.

(e) Boxed or crated materials or those in sealed containers shall remain in their

original boxes, crates or containers.


14.3.19 Handling of pipes and fittings

(a) Pipes and fittings other than thin walled pipes shall be handled by manual methods or by using lifting appliances or chains, wire rope or canvas slings of a type recommended by the pipe manufacturer and reviewed without objection by the Project Manager. Hooks shall not be used.

(b) Slings shall be placed around the pipes and fittings and padding shall be

provided at points of contact between pipes and fittings and metal lifting appliances or slings. Pipes and fittings shall not be handled by means of metal slings passed through the pipes.

(c) Pipes and fittings shall not be subjected to rough handling, shock loading or

dropping. 14.3.20 Storage of pipes

(a) Pipes other than thin walled pipes shall be stored horizontally at least 75 mm above the ground on wedged timber bearers. The pipes shall be securely wedged to prevent sideways movement.

(b) Socket and spigot pipes shall be stored with the sockets alternating and in

such a manner that loads are not applied to the sockets. (c) The height of stacks of pipes other than thin walled pipes shall not exceed the

maximum height recommended by the pipe manufacturer. (d) Pipes shall not be strung out along the route of the pipeline.

14.3.21 Transport of thin walled pipes

When being transported, thin walled pipes shall be supported on three rubber covered saddles shaped such that the pipes are supported over at least one-quarter of the circumference. The pipes shall be securely fixed in position at each saddle by straps tightened by turnbuckles. One saddle shall be placed at the mid-point of the length of the pipe and the other two saddles shall be placed at distances of one-fifth of the length of the pipe from each end of the pipe.

14.3.22 Handling and storage of thin walled pipes

(a) When being handled and stored, thin walled pipes shall be protected from deformation by means of at least two screw jack cruciform struts with rubber padded ends shaped to fit the circumference of the pipes. The struts shall be fitted inside the pipes; any temporary struts fixed by the manufacturer shall be left in position until the cruciform struts have been fixed.

(b) Thin walled pipes shall be handled by using two reinforced canvas slings at

least 300 mm wide. The slings shall be suspended from a lifting beam and shall be placed at a distance of one-fifth of the length of the pipe from each end of the pipe.

(c) Thin walled pipes shall not be rolled.


(d) Thin walled pipes shall be stored on timber bearers padded with hessian or straw to provide continuous support over at least one-third of the circumference of the pipe. The pipes shall be securely fixed in position with wedges placed at a distance of one-fifth of the length of the pipe from each end of the pipe.

(e) Thin walled pipes shall not be stacked on top of each other.

14.4 SUBMISSIONS 14.4.1 Particulars of independent inspection authority

Particulars of the proposed independent inspection authority for pipes, joints, fittings and valves for water supply pipeworks, including name and address, previous experience, and names of inspectors, shall be submitted to the Project Manager for review without objection.

14.4.2 Particulars of pipes, joints and fittings

(a) The following particulars of the proposed pipes, joints and fittings for water supply pipeworks shall be submitted to the Project Manager for review without objection:

(i) manufacturer's literature, including details of:

• manufacturing process; • pressure and temperature ratings; • permissible values of straight draws and angular deflection of

flexible joints; • re-commendations for handling, storage, laying, jointing and repair;

and • drilling and tapping equipment for connections to pipes;

(ii) a certificate for each material showing the manufacturer's name, the

date and place of manufacture and showing that the material complies with the requirements stated in the Contract and including results of tests required in accordance with the relevant British Standard;

(iii) three copies of Contractor’s Drawings showing details of the pipes,

joints and fittings, including the materials used and the mass of each item; and

(iv) a certificate of inspection of the manufacture and testing signed by the

independent inspection authority reviewed without objection by the Project Manager.


14.4.3 Particulars of pressure tests

(a) The following particulars of the proposed procedures for pressure tests on pipelines for water supply pipeworks shall be submitted to the Project Manager for review without objection:

(i) test equipment and method of setting up the equipment;

(ii) calibration certificates for pressure gauges;

(iii) procedure for carrying out the test; and

(iv) programme for testing.

14.4.4 Particulars of Anticorrosion tape

The following particulars of the proposed anticorrosion tape for water supply pipeworks shall be submitted to the Project Manager:

(a) manufacturer’s literature for anticorrosion tape; and (b) certificate for anticorrosion tape showing the manufacturer’s name, the date

and place of manufacture and showing that the material complies with the requirements stated in the Contract and including results of tests in accordance with the Contract.

14.5 WORKMANSHIP 14.5.1 Access to pipelines

(a) Rubber wheeled trolleys shall be provided to obtain access inside pipelines exceeding DN 500 for water supply pipeworks in order to joint pipes, repair joints, coatings and linings and inspect the pipeline. Persons entering pipelines shall wear clean soft-soled footwear.

(b) Mechanical fans shall be provided to ensure that an adequate air supply is

available to those entering pipelines for inspection. Engine driven fans shall be fitted with a flexible exhaust or other methods of keeping exhaust fumes clear of the fresh air intake.

14.5.2 Laying pipes

(a) The Contractor shall notify the Project Manager before pipelaying starts in any part of the Permanent Works.

(b) The Contractor shall inspect pipes, joints, fittings and valves, including internal

and external coatings, immediately before and after pipelaying; valves shall be inspected to ensure that they are in working order and are capable of being fully opened and closed. Deleterious material shall be removed and damage shall be repaired immediately before and after pipelaying; potable water shall be used for washing.


(c) The inside of pipelines shall be kept clean and free from water, dirt, stones, debris and deleterious material. Except when pipes are being jointed, the open ends of pipelines shall be sealed with a wooden plug or stopper.

(d) Measures shall be taken to prevent flotation of pipes.

(e) Pipelaying shall follow closely on excavation of the trench. Lengths of trench

which in the opinion of the Project Manager are excessive shall not be left open.

(f) Pipelines with a gradient steeper than 1 in 20 shall be laid in an uphill

direction with sockets facing uphill. (g) Pipes shall be laid in such a manner that water will not pond in locations with

either zero or shallow gradients, and the line and level of pipes shall comply with the specified tolerances.

14.5.3 Laying pipes with flexible joints

The degree of the curve of pipes for water supply pipeworks with flexible joints which are to be laid to a curve shall be equally distributed over all joints within the curved section. The deflection at a completed joint shall not exceed 3° or three-quarters of the maximum deflection recommended by the manufacturer whichever is less.

14.5.4 Installation of valves

(a) Operating gear and associated fittings shall be installed and fixed at the same time as valves, for water supply pipework, are installed. After installation, valves shall be cleaned inside and outside and left in a closed position.

(b) Extension keys and clamps shall be fixed to valves in valve chambers if the

vertical distance between the top of the valve spindle and the finished ground level exceeds 600 mm. The length of extension keys shall be such that the top of the extension key is not more than 300 mm below the finished ground level.

14.5.5 Bedding pipes

(a) Surfaces on which pipes for water supply pipeworks will be laid shall be cleaned and objects which may damage the pipes shall be removed before pipes are laid.

(b) The bottom of trenches on which pipes will be laid directly shall be shaped to

support the pipes uniformly along the length of the barrel; holes shall be dug to prevent pipes resting on the sockets and to allow the pipes to be jointed.

14.5.6 Cutting pipes

(a) Pipes for water supply pipeworks shall be cut and the ends shall be prepared in accordance with the manufacturer's recommendations. Pipes shall be cut using purpose made equipment recommended by the manufacturer and reviewed without objection by the Project Manager.


(b) Cut ends of pipes shall be square and even, without damage to the pipe or coating. Cut ends, including cut ends of the piece not immediately required, shall be trimmed and chamfered to suit the type of joint and in such a manner that elastomeric joint rings will not be damaged by the cut end.

(c) Pipes requiring to be cut to form closing lengths shall not be cut until adjacent

pipes have been laid and jointed and the length to be cut can be accurately measured.

14.5.7 Drilling pipes

Drilling in water pipelines for pipe connections shall be prohibited..

14.5.8 Jointing pipes

(a) Pipes for water supply pipeworks shall be jointed in accordance with the manufacturer's recommendations and using jointing equipment and jointing materials recommended by the manufacturer and reviewed without objection by the Project Manager.

(b) The Contractor shall inspect pipes, joints, fittings and valves, including internal

and external coatings, immediately before and after jointing. Deleterious material shall be removed and damage shall be repaired immediately before and after jointing; potable water shall be used for washing. Surfaces which are to be jointed and jointing materials shall be cleaned immediately before jointing.

(c) All joints in pipelines shall be watertight. (d) The widths of gaps at joints shall be in accordance with the manufacturer's

recommendations and shall be achieved by marking the outside of the pipe or by using metal feelers. The position of elastomeric joint rings shall be checked by using metal feelers after jointing.

(e) Gaps at joints in pipes shall be protected after jointing by methods reviewed

without objection by the Project Manager to prevent dirt, stones or other material entering the joint.

(f) Bolt holes in flanged joints and joints incorporating bolted components shall

be correctly orientated before the bolts are tightened. The correct size of bolts and nuts shall be used. Bolt threads shall be lubricated and bolts shall be tightened using the correct size of spanner. Bolts shall be tightened in diametrically opposite pairs working around the bolt circle until all bolts are tightened to the torque recommended by the manufacturer.

(g) Bolt holes in flanged joints shall be orientated symmetrically about the vertical

diameter with no bolt holes on the vertical diameter. Elastomeric joint rings shall be the correct size and shall not protrude into the bore of the pipe. The rings may be temporarily fixed to the face of the flange using a minimum amount of adhesive of a type recommended by the manufacturer; jointing compound or paste shall not be used.


14.5.9 DI pipes with push-in joints

DI pipes with push-in joints for water supply pipeworks shall be jointed by smearing the spigot end of the pipe with lubricant and placing the elastomeric joint ring in position inside the groove of the socket end of the laid pipe. The spigot end of the pipe shall be placed in the socket end of the laid pipe and pushed home.

14.5.10 DI pipes with mechanical joints

(a) DI pipes with mechanical joints for water supply pipeworks shall be jointed as stated in Clauses 14.5.10(b) to (d).

(b) The elastomeric joint ring and the ends of the pipe shall be smeared with

lubricant over a distance recommended by the manufacturer. (c) The gland and the elastomeric joint ring shall be placed in position on the

spigot end of the pipe. (d) The spigot end of the pipe shall be placed in the socket end of the laid pipe

before the bolts are tightened. 14.5.11 Repairs to joints, coatings and linings

(a) Joints and damage to coatings and linings of pipes, joints and fittings for water supply pipeworks shall be repaired as stated in Clauses 14.5.11 to 14.5.13.

(b) Repairs to joints, coatings and linings shall be carried out using materials of

the same type and grade as in the pipe, joint or fitting. (c) External repairs shall be completed before internal repairs are carried out. (d) Internal repairs and adjacent areas shall be washed with potable water after

the repair is complete. 14.5.12 Repairs to DI pipes with bitumen coatings

Internal and external repairs to joints and coatings of DI pipes with bitumen coatings shall be carried out using bituminous paint. The area to be repaired shall be cleaned to bare metal and dried. The area to be repaired shall be painted with bituminous paint to the same thickness as the adjacent coating; the paint shall be finished to a smooth uniform surface.

14.5.13 Internal repairs to DI pipes with cement mortar lining

(a) Internal repairs to joints and linings of DI pipes with cement mortar linings shall be carried out as stated in Clause 14.5.13(b) to (d).

(b) The area to be repaired shall be cut back to leave clean, bright metal. The

area surrounding the area to be repaired shall be wetted.


(c) The cement mortar shall be worked into the area to be repaired and compacted to the same thickness as the adjacent lining; the cement mortar shall be finished to a smooth uniform surface. The repaired area shall be cured with curing compound as stated in Clause 20.5.6.

(d) The inside of pipe sockets and the faces of flanges shall be kept free from

cement mortar.

14.5.14 Thrust and anchor blocks

(a) The bearing face, and other faces stated in the Contract, of concrete thrust and anchor blocks for water supply pipeworks shall be cast directly against undisturbed ground; the faces of excavations shall be trimmed to remove loose material before concreting. Excess excavation and working space shall be filled with concrete of the same grade as the block.

(b) Internal pressure shall not be applied to the pipeline until thrust and anchor

blocks have developed the specified grade strength. 14.5.15 Concrete bed, haunch and surround

(a) Concrete bed, haunch and surround to pipelines for water supply pipeworks

shall be constructed as stated in Clause 14.5.15(b) to (e). (b) Pipes shall be supported at the required level by Grade 20 precast concrete

wedges, blocks or cradles. One support shall be placed adjacent to each end of each pipe and the spacing between supports shall not exceed 3 m. Compressible sheeting shall be placed between the pipes and supports.

(c) Flexible joints shall be formed in concrete bed, haunch and surround at

flexible joints in pipelines. Joint filler shall be placed next to the flexible joint in the pipeline and shall extend for the complete thickness of the bed, haunch and surround.

(d) Polyethylene sheeting shall be placed on the trench bottom before concreting. (e) Concrete shall be placed evenly over the complete width of the bed and over

the complete length of the pipe being concreted up to a level of 25 mm below the underside of the pipe. Concrete shall then be placed on one side of the pipe only and worked under the pipe until the concrete spreads under the pipe. Concrete shall then be placed equally on both sides of the pipe to the specified level.

14.5.16 Tolerances : pipelines

The line and level of pipelines for water supply pipeworks shall be within 25 mm of the specified line and level.

14.5.17 Tolerances : manholes and chambers

The finished level of manholes and chambers shall be within 5mm of the specified level.


14.6 INSPECTION, TESTING AND COMMISSIONING 14.6.1 Inspection of manufacture and testing

(a) The manufacture and testing of pipes, joints, fitting and valves for water supply pipeworks shall be inspected by an independent inspection authority reviewed without objection by the Project Manager.

(b) The inspections shall be carried out at the manufacturer's works or at other

locations stated in the Contract or directed by the Project Manager. The facilities and equipment required for inspections shall be provided by the Contractor.

14.6.2 Pipe jointing trials

(a) Trials shall be carried out to demonstrate that the pipes, joints and fittings for water supply pipeworks fit correctly.

(b) The trials shall be carried out at least 6 weeks before the materials are

proposed to be incorporated in the Permanent Works. (c) The Contractor shall notify the Project Manager before carrying out trials. (d) The Contractor shall immediately notify the Project Manager of any pipes,

joints or fittings which do not fit correctly. Modifications shall be made to pipes, joints and fittings which do not fit correctly or replacements shall be provided as directed by the Project Manager.

14.6.3 Trials for drilling and tapping

(a) Trials shall be carried out to demonstrate that the proposed equipment and methods of drilling and tapping pipes for water supply pipeworks will produce connections which comply with the specified requirements.

(b) The trials shall be carried out at least 14 days before drilling and tappingis

programmed to commence. (c) The Contractor shall notify the Project Manager before carrying out trials.

14.6.4 Polyethylene pipe manufacturing quality control

(a) For quality control on manufacturing of the pipes, the following tests listed in ISO 4427 shall be subject to inspection by the independent inspection authority:

(i) Clause 3.3; (ii) Clause 3.7 – melt flow rate test only;

(iii) Clauses 4.1 and 4.2;

(iv) Clause 5.1 – 100 hour at 20°C and 165 hour at 80°C only; and

(v) Clause 6.3(b).


(b) For quality control on manufacturing of the compression fittings, the following tests listed in ISO 14236 shall be subject to inspection by the independent inspection authority:

(i) Clause 6.1; and (ii) Clauses 8.3.4.2 and 8.3.4.3.

(c) Polyethylene materials for both PE80 and PE100 shall be tested in

accordance with the Chlorine Water Test specified in Clause 9.8 of the Japanese Industrial Standard (JIS) K6762 and the performance of the polyethylene materials shall comply with the chlorine-water resistance for single wall pipe specified in Clause 5 of the JIS K6762. Test certificates shall be submitted to the Project Manager for review without objection.

14.6.5 Sampling polyethylene pipes

(a) Sampling procedures for inspection shall be in accordance with BS6001 : Part

1 unless specified otherwise and shall meet the following requirements: (b) Sample size for dimensional, appearance, casting quality and BS21 threading

checks on pipe materials shall be determined in accordance with BS6001 : Part 1 at Inspection Level II for single sampling plan. Materials from different sources shall be sampled as isolated batches. Normal inspection shall be used at the start of inspection. Inspection may be switched to tightened or reduced inspection and switched back to normal inspection in accordance with the procedures stipulated in Clause 9.3 of BS6001:Part 1. Acceptable Quality Level (AQL) shall be 4.0.

(c) For material and marking checks, one sample shall be selected from each

type and size of pipe materials in each batch. Materials from different sources shall be sampled as isolated batches.

14.6.6 Testing Polyethylene Pipes

(a) Water/Hydrostatic Pressure Test

(i) Notwithstanding Clause 6.1 of BS6001 : Part 1, each batch shall, as far as practicable, consist of units of pipes of a single type, grade, class and composition, of different sizes, manufactured under essentially the same conditions, and at essentially the same time. Two samples shall be selected from each size of the pipes in each batch.

(ii) Duration of tests shall be in accordance with the relevant specification. (iii) Tests shall be witnessed before any finishing treatment. (iv) Acceptance criteria shall be no failure of witnessed water/hydrostatic

pressure tests.


14.6.7 Testing Polyethylene Fittings

(a) Water/Hydrostatic Pressure Test

(i) Notwithstanding Clause 6.1 of BS6001 : Part 1, each batch shall, as far as practicable, consist of units of pipes of a single type, grade, class and composition, of different sizes, manufactured under essentially the same conditions, and at essentially the same time. Two samples shall be selected from each size of the pipes in each batch.

(ii) Duration of tests shall be in accordance with the relevant specification. (iii) Tests shall be witnessed before any finishing treatment. (iv) Acceptance criteria shall be no failure of witnessed water/hydrostatic

pressure tests. 14.6.8 Cleaning and sterilisation of pipelines

(a) Fresh water and potable water pipelines for water supply pipeworks shall be cleaned and flushed through with potable water. Cleaning and flushing shall be carried out:

(i) before and after the complete pipeline, or part thereof permitted by the

Project Manager, has been tested; (ii) after the Temporary Works required for testing have been removed; and

(iii) after parts of the pipeline removed for testing have been reconnected.

(b) The pipeline shall be completely filled with water that has been dosed with a

homogeneous solution of sterilising chemicals such that the final concentration of free chlorine in the water is at least 30 ppm. The water shall be left in the pipeline for at least 24 hours.

(c) After the 24 hour period, the pipeline shall be drained down and the sterilising

water shall be flushed out using potable water until the concentration of the remaining chlorine is less than 1 ppm.

(d) Pipelines shall be cleaned and sterilised not more than 7 days before the

application for Completion Certificate. (e) Swabbing shall be carried out to the pipes not exceeding DN600.


(f) Swabs shall be of a proprietary brand obtained from a manufacturer reviewed without objection by the Project Manager and used in accordance with the manufacturer's instructions. They shall be of a compressible hard grade polyurethane foam in cylindrical shape and shall have the following diameters:

DN OF PIPE Diameter of Swab

Up to 300 mm Pipe DN + 25%

Above 300 mm Pipe DN + 75 mm

Swabs shall be suitable for clearing out new pipelines and removing dirt and materials inadvertently left in the pipeline during construction. Swabs may be fitted with a signalling device to enable the swab to be located within the pipeline.

(g) The Contractor shall be responsible for the supply of water to the place where swabbing work is required and if necessary, pressurize the water to a level sufficient for the swabbing work.

(h) The swab shall be inserted into a short plain ended pipe at ground level

adjacent to the trench and the pipe shall then be fitted, by means of flange adaptors, into position in the pipeline between two gate valves which shall then be opened to allow the swab to pass through the pipeline.

(i) The swab shall be fully immersed in water during the entire operation using

water as the driving medium. Foam swabs shall not be air driven and the water must not drain away from the swab on downhill sections. The velocity of the swab, which shall be controlled by the rate of flow of water downstream of the swab, shall be kept within a range of 300 mm/sec to 1200 mm/sec.

(j) All air valves and valves on tees/branches from the pipeline shall be closed

before swabbing work commences. (k) At least 14 days before the swabbing operation is to be carried out, the

Contractor shall submit the following information for review without objection by the Project Manager:

(i) Name and address of supplier of swab, (ii) Place and name of manufacturer, (iii) Type and grade of swab, (iv) Manufacturer's recommended instructions for use, (v) Details of previous applications of the proposed type of swab, (vi) Programme and details of swabbing operation, and (vii) Means of recovering swab from pipeline at the end of the swabbing run.


14.6.9 Testing: pressure pipelines for water supply pipeworks

(a) Pressure pipelines for water supply pipeworks shall be tested as stated in Clause 14.6.9(b) to (f).

(b) The pipeline shall be tested in sections as stated in the Contract unless

otherwise permitted by the Project Manager; if testing in sections other than those stated in the Contract is permitted, the section to be tested shall be as long as practicable provided that the specified test pressure will not be exceeded. Final tests on complete pipelines which have been tested in sections shall not be carried out unless stated in the Contract.

(c) The test pressure shall be as stated in the Contract. If the test pressure is not

stated in the Contract, the test pressure shall be:

(i) 1.5 times the maximum working pressure if the maximum working pressure does not exceed 1.5 Mpa; or

(ii) 1.3 times the maximum working pressure if the maximum working

pressure exceeds 1.5 MPa.

(d) Unless otherwise permitted by the Project Manager, pressure tests shall not be carried out until fill material has been deposited and compacted over the complete length of the pipeline to be tested; if permitted, sufficient fill material shall be deposited to restrain the pipeline in position during the test.

(e) Tests shall not be carried out simultaneously on pipelines in the same trench. (f) The method of testing shall be in accordance with Appendix A14.1. (g) The pipeline shall be left charged with water at a head of at least 15 m after

testing and until the pipeline has been sterilized. 14.6.10 Compliance criteria: pressure pipelines for water supply pipeworks

The results of tests on pressure pipelines for water supply pipeworks shall comply with the following requirements:

(a) the leakage of water from the pipeline determined by the pressure test shall

not exceed the permitted leakage calculated in accordance with Clause A14.1.4 in Appendix A14.1; and

(b) there shall be no discernable leakage of water from the pipeline or from any

joint during the pressure test. 14.6.11 Non-compliance: pressure pipelines for water supply pipeworks

If the result of any test on pressure pipelines for water supply pipeworks does not comply with the specified requirements for the test, the Contractor shall investigate the reason. Remedial or replacement work reviewed without objection by the Project Manager shall be carried out and the pipeline shall be retested.


14.6.12 Testing: water sterilisation

After the pressure test on fresh water and potable water pipelines have been completed, samples of the water in the pipelines shall be taken by the Contractor in the presence of the Project Manager. The number of samples and locations of sampling shall be as directed by the Project Manager. Testing shall be carried out as stated in Clauses 24.6.11 to 24.6.12 for water sterilisation of water retaining structures. The colour, odour, appearance, turbidity, conductivity, free residual chlorine, E.Coli, total coliforms, total bacterial count and pH values of the water samples shall be tested to demonstrate the quality of each sample of water is comparable to that drawn from the supply point and the results shall be reviewed without objection by the Project Manager.


APPENDIX A14.1

PRESSURE TESTS ON PIPELINES A14.1.1 Scope This method covers the determination of the leakage of water from pipelines for

water supply pipeworks by means of a pressure test. A14.1.2 Equipment The following equipment is required:

(1) blank flanges or caps; (2) struts and wedges; (3) temporary concrete blocks or other anchors; (4) force pump and pump feed tank; (5) pressure gauge, readable and accurate to 0.01 m head; and (6) continuous pressure recorder and purpose made charts.

A14.1.3 Procedure The procedure shall be as follows:

(1) pipes and valves shall be checked for cleanliness and the operation of valves shall be checked;

(2) blank flanges or caps shall be fixed to the ends of the pipeline, or section of

the pipeline, to be tested. Tests shall not be made against valve gates; (3) the blank flanges and caps shall be secured with struts and wedges against

temporary concrete blocks or other anchors. The blocks and anchors shall be completed and shall have hardened sufficiently before testing starts;

(4) thrust and anchor blocks, pipe straps and other devices required to prevent

movement of pipes and fittings shall be completed before testing starts; (5) the pipeline shall be filled with water and all air shall be removed; (6) the pipeline shall remain filled for 3 days before testing starts to allow

absorption to take place and to achieve conditions which are as stable as practicable;

(7) the pressure in the pipeline shall be increased slowly to the specified test

pressure by pumping water into the pipeline using a force pump; (8) the pressure in the pipeline shall be maintained within +0% and -5% of the

specified test pressure for a test period of at least 2 hours;


(9) at the beginning and end of the test period and at 30 minute intervals during the test period, readings shall be taken from the pressure gauge and the pressures (p) shall be recorded. The pressure shall be adjusted to the specified test pressure each time a reading is taken;

(10) the pressure shall be adjusted to within the specified tolerances for the test

pressure at any time during the test period if the pressure falls outside the specified tolerances;

(11) the pressure shall be monitored during the test by means of a continuous

pressure recorder with purpose made charts; and (12) the leakage of water from the pipeline shall be measured as the amount of

water required to maintain the specified test pressure in the pipeline; the amount of water shall be determined from the fall in level of water in the pump feed tank.

A14.1.4 Calculation

(1) The average test pressure (P) shall be calculated as the average of the pressures (p) recorded during the test.

(2) The permitted leakage of water from the pipeline during the pressure test

shall be calculated from the equation: t P Permitted leakage = 0.02 x d x l x x litre 24 10 where:

- d is the nominal diameter of the pipe (mm) - l is the length of pipeline tested (km) - t is the test period (hr) - P is the average test pressure (m)


The following shall be reported: (1) the internal diameter of the pipe to the nearest 1 mm; (2) the length of pipeline tested to the nearest 1 m; (3) the test period to the nearest 0.01 hr; (4) the pressures recorded during the test to the nearest 0.01 m; (5) the average test pressure to the nearest 0.01 m; (6) the leakage and permitted leakage of water to the nearest 0.1 litre;


(7) details of any discernable leakage of water from the pipeline during the test;

(8) charts obtained from the continuous pressure recorder; and (9) that the test method used was in accordance with this General Materials and


General Materials & Workmanship Specification 1/1 January 2011 Issue No. 5, Volume 1 – Civil & Structural Works Section 15 – Not Used

SECTION 15 NOT USED

General Materials & Workmanship Specification 1/1 Janaury 2011 Issue No. 5, Volume 1 – Civil & Structural Works Section 16 – Not Used

SECTION 16 NOT USED

Materials & Workmanship Specification 1/40 January 2011 Issue No. 5, Volume 1 – Civil & Structural Works Section 17 – Piling Works

SECTION 17 PILING WORKS

17.1 GENERAL 17.1.1 General Requirements


(a) Earthworks shall comply with Section 7. (b) Steel reinforcement shall comply with Section 19. (c) Concrete shall comply with Section 20. (d) Materials for grout for piling works shall comply with Section 20. (e) Grouting for piling works shall comply with Section 21. (f) Prestressing shall comply with Section 21. (g) Steelwork shall comply with Section 22.

17.2 DEFINITIONS AND ABBREVIATIONS 17.2.1 Barrette

A barrette is a pile formed by excavation using grabs and chisels through a thixotropic suspension of bentonite or other agent which supports the sides of the shaft as excavation proceeds, and which is concreted in one continuous operation.

17.2.2 Bored Piles

Bored piles are cast-in-situ concrete piles formed by boring or grabbing. Piles with a diameter 600 mm or less are commonly referred to as small diameter piles, while piles with a diameter greater than 600 mm are referred to as large diameter piles.

17.2.3 Minipiles

A minipile is a pile with a diameter of less than 400 mm in which the load bearing element consists of one or more steel reinforcement bars. Permanent steel casing above rockhead level is used to contain the grout.

17.2.4 Rock-Socketted Steel H-piles

A rock socketted steel H-pile is a pile formed by inserting a steel H-pile in a pre-bored hole sunk into Grade III or better rock, with a temporary steel casing above the rock head level and subsequent filling of the holes with cement grout.

17.2.5 Driven Steel H-piles

A driven steel H-pile is a H-section steel pile installed by percussive methods.


17.2.6 Continuous Flight Augur Piles

A continuous flight augur pile is a pile formed by a flight augur and subsequent pressurized injection with cement-sand grout through the augur’s stem as it is being withdrawn.

17.3 RELEVANT CODES AND STANDARDS 17.3.1 Regulations, Codes of Practice, Design and Quality Supervision Guidelines

and Site Safety Supervision

Piling works shall comply with the Building (Construction) Regulations of Hong Kong, Practice Notes for Authorised Persons and Registered Structural Engineers (PNAP) and other codes and standards set out below.

17.3.2 Pile Caps

Pile caps shall comply with the Hong Kong Code of Practice for the Structural Use of Concrete in respect of all materials and workmanship for reinforced concrete pile caps and for structural concrete above piles. Where BS 8110 is used, specific requirements as specified in PNAP 187 shall be followed. Editions of BS 8110 other than the 1985 version shall not be used unless otherwise reviewed without objection by the Project Manager.

17.3.3 Safety of Piling Works

Piling works shall comply with the following;

(a) Code of practice for site safety supervision

(b) Technical memorandum for site safety

(c) BS 8004: Code of practice for foundations (d) BS 5573: Code of practice for safety precautions in the construction of large

diameter boreholes for piling and other purposes

17.3.4 Specialist Foundation Contractor

All piling works shall be carried out by a Registered Specialist Contractor (Foundation Works) under the Buildings Ordinance except where exempted in PNAP 214.

17.4 MATERIALS 17.4.1 Steel Piles

(a) Steel bearing piles shall be of a proprietary section reviewed without objection by the Project Manager.

(b) Steel sheet piles shall be of a proprietary section reviewed without objection

by the Project Manager.


(c) Steel bearing piles and steel sheet piles shall be manufactured from Grade 50B steel and comply with BS 4360 and BS 5950:Part 2.

(d) Steel pipe piles shall comply with BS 3601 or BS 6232:Parts 1 and 2, except

for the requirements of hydraulic pressure tests. (e) All steel piles shall be free from loose scale and rust.

17.4.2 Pile Shoes

(a) Pile shoes for driven cast-in-place piles shall be manufactured from durable materials capable of withstanding driving stresses without damage. The shoes shall be designed to provide a watertight joint with permanent casings.

(b) Cast steel pile shoes for steel bearing piles shall be manufactured from steel

complying with BS 3100, Grade A. (c) Welded fabricated pile shoes for steel bearing piles shall be manufactured

from steel complying with BS 4360, Grade 43A. 17.4.3 Epoxy Paint

Epoxy based paint for epoxy coatings to steel piles shall be a proprietary type reviewed without objection by the Project Manager.

17.4.4 Bituminous Coating Material

Bituminous coating material for steel piles shall be hot-applied filled or unfilled bituminous material complying with BS 4147.

17.4.5 Grout for Piling Works

(a) Grout for piling works shall consist of OPC and water. Sand, PFA and admixtures may be used subject to review without objection by the Project Manager.

(b) The minimum cementitious content of grout shall be 600 kg/m3. (c) Grout used to fill core holes shall be non-shrink grout and have a minimum

characteristic compressive strength of not less than the specified grade strength of the concrete surrounding the core hole.

(d) Grout used to fill minipiles and pre-bored rock socketted steel H-piles shall be

non-shrink grout and have a minimum characteristic compressive strength of 30 MPa at 28 days.

(e) Water used in the grout must be clean and fresh with a temperature not

exceeding 30°C nor less than 5°C. (f) The maximum amount of bleeding of grout shall not exceed 2% in the first 3

hours and shall not exceed 4% in total; the water shall be reabsorbed by the grout during the 24 hours after mixing.

(g) Free expansion of grout shall not exceed 10% at the ambient temperature.


(h) The chloride ion content of admixtures for concrete containing embedded metal or for concrete made with SRPC shall not exceed 2% by mass of the admixture or 0.03% by mass of the cementitious content, whichever is less.

(i) The maximum total chloride content of grout, expressed as a percentage

relationship between the chloride ion and the cementitious content by mass in the grout, shall not exceed 0.1%.

(j) Admixtures shall be chloride free and comply with BS 5075 and shall be

submitted for review without objection by the Project Manager before use.

17.4.6 Reinforcement Connectors

(a) Reinforcement connectors shall be of a proprietary type reviewed without objection by the Project Manager.

(b) Connectors shall be capable of transmitting the total pile load in tension or

compression as appropriate. (c) Connectors for tension joints shall be:

(i) cold swaged or threaded type; (ii) capable of developing the full tensile strength of the parent bar; and

(iii) comprised of high tensile studs and seamless steel tubes fitted with

protective plastic caps.

(d) Connectors for compression joints, shall be wedge locking, bolted sleeve type. 17.4.7 Surface Treatment of Steel Piles

(a) Surface preparation and application of protective coatings other than bituminous coatings to steel piles shall be carried out in a fully enclosed well-ventilated workshop.

(b) The method of application of protective coatings to steel piles, the ambient

temperature and humidity at the time of application and the time interval between the application of successive coats shall be in accordance with the manufacturer's recommendations. The complete coating shall be applied in and around clutches.

17.4.8 Surface Preparation of Steel Piles

The surfaces of steel piles to which protective coatings will be applied shall be prepared by blast cleaning to either: (a) second quality of surface finish in accordance with BS 4232; or

(b) Sa21/2 in accordance with Swedish Standard SIS 05 59 00.


17.4.9 Epoxy Coatings to Steel Piles

(a) Epoxy coatings to steel piles shall consist of three coats of epoxy based paint, each coat having a minimum dry film thickness of 75 μm. The first coat shall be applied within two hours of blast cleaning.

(b) The finished surface of epoxy coatings shall be smooth with a dense and

uniform texture and shall be free from sharp protuberances and pinholes. The thickness and continuity of completed epoxy coatings shall be measured using a magnetic thickness gauge.

(c) Damaged areas of epoxy coatings shall be repaired by cleaning the damaged

areas to bare metal, feathering back the adjacent areas with coarse grade sand-paper and re-applying the coatings.

17.4.10 Bituminous Coatings to Steel Piles

(a) Bituminous coating material, or primer if the bituminous coating consists of a built-up system, to steel piles shall be applied within two hours of blast cleaning. The thickness of bituminous coatings shall be at least 300 μm.

(b) Damaged areas of bituminous coatings shall be cleaned back and overcoated

with the same bituminous coating material to restore the specified thickness. (c) Steel H-piles shall be protected with a bituminous coating for eight (8) metres

below cut-off level.

17.4.11 Surface Treatment of Extended Steel Piles

The splice areas of steel piles which are extended in-situ shall be prepared by blast cleaning prior to splicing. The protective coating shall be re-applied to the splice area before the piles are driven.

17.4.12 Removal of Protective Coatings to Steel Piles

Protective coatings shall be removed from the heads of steel piles which will be encased in concrete by blast cleaning or flame cleaning. The coatings shall be removed to a level of 75 mm above the underside of the concrete into which the pile will be encased.

17.4.13 Handling and Storage of Piles

(a) The identification number, grade of steel and length of pile shall be marked on steel piles.

(b) Piles shall be stored horizontally off the ground on level supports and in a

manner which will not result in damage to the coatings. Bituminous coated piles shall not be stacked.

(c) Different types and sizes of piles shall be stored separately.


17.4.14 Handling and Storage of Bentonite

Bentonite shall be handled and stored in a manner which will not result in spillages on Site. It shall be stored in cool dry conditions and particular care shall be taken with bulk storage to prevent balling of the bentonite powder due to damp, or deterioration of properties due to damp and heat.

17.5 SUBMISSIONS 17.5.1 Particulars of Piling Works

(a) The following particulars of the proposed materials and methods of construction for piling works shall be submitted to the Project Manager for review without objection:

(i) details of Contractor's Equipment;

(ii) methods and sequence of installation of piles, including methods of

avoiding damage to adjacent piles, structures and utilities and measures to be taken to deal with hard material and obstructions;

(iii) details of material for steel piles, including mill certificates;

(iv) calculations of driving stresses;

(v) methods of jointing and lengthening piles;

(vi) details of reinforcement splices;

(vii) methods of controlling groundwater, or groundwater treatment;

(viii) anticipated ground vibration, ground movement and groundwater

drawdown, methods of instrumentation and monitoring, and details of monitoring and measurement instrumentation;

(ix) methods and sequence of excavation, including methods of supporting

excavations and of cleaning the excavation;

(x) methods of concreting or grouting;

(xi) details of protective coatings to steel piles, including manufacturers' literature;

(xii) details of preliminary piles; and

(xiii) methods of testing , including details of the specialist firm, independent

from the Contractor, proposed to carry out non-destructive testing of welds and the programme for integrity testing.


17.5.2 Particulars of Construction using Bentonite Slurry

(a) The following particulars of the proposed materials and methods of construction using slurry containing bentonite or other similar agent shall be submitted to the Project Manager for review without objection:

(i) a certificate for bentonite showing the type, the manufacturer's name,

the date and place of manufacture and including details of the apparent viscosity range in Pa.s and the gel strength range in N/m2 for solids in water;

(ii) characteristics of the bentonite slurry in a freshly mixed condition and in

the excavation immediately before concreting;

(iii) methods of quality control, sampling, testing, mixing, storing, recirculating, removing silt and sand, preventing spillages and disposal from Site;

(iv) head of bentonite slurry, including stability calculations;

(v) details of guide walls;

(vi) methods of placing concrete by tremie; and

(vii) sequence of construction.

17.5.3 Particulars of Minipiles

(a) The following particulars of the proposed materials and methods of construction for minipiles shall be submitted to the Project Manager for review without objection:

(i) details of pile head, reinforcement and permanent steel casing including

spacers and couplings;

(ii) details of grout mix as stated in Clause 21.4.3 including fine aggregate and admixtures as appropriate;

(iii) sequence and timing of grouting, including details of secondary pressure

grouting;

(iv) method of installation including equipment to be used, sequence of operations, drilling methods, casing installation and time of grouting; and

(v) minimum length of rock socket for each pile.


17.5.4 Particulars of Rock-Socketted Steel H-piles in Pre-Bored Holes

(a) The following particulars of the proposed materials and methods of construction for rock-socketted steel H-piles shall be submitted to the Project Manager for review without objection:

(i) details of pile head, steel H-pile and the external casing, including splice

joint and welding details;

(ii) details of grout mix as stated in Clause 21.4.3 including fine aggregate and admixtures as appropriate;

(iii) sequence and timing of grouting, including details of secondary pressure

grouting;

(iv) method of installation including equipment to be used, sequence of operations, drilling methods, casing installation and time of grouting; and

(v) minimum length of rock socket for each pile.

17.5.5 Particulars of Continuous Flight Auger Piles

(a) The following particulars of the proposed materials and methods of construction for continuous flight auger piles shall be submitted to the Project Manager for review:

(i) details of reinforcement including spacers and couplings;

(ii) details of grout mix as stated in Clause 21.4.3 including fine aggregate

and admixtures as appropriate;

(iii) sequence and timing of grouting, including details of secondary pressure grouting;

(iv) method of installation including equipment to be used, sequence of

operations, drilling methods, casing installation and time of grouting; and

(v) length of piles when designed as friction piles or rock socket detail when designed as end bearing piles.

17.6 WORKMANSHIP 17.6.1 Commencement of Piling Works

Piling works, including groundwater control and ground treatment for piling works, shall not commence until:

(a) “Site Safety Supervision Plan” and “Quality Supervision Plan” as stipulated in

the PNAP 242 are submitted to the satisfaction of the Buildings Department and the Project Manager;


(b) consent to the commencement of piling works has been given by the Buildings Department; and

(c) proposed materials and methods of construction, including construction and

testing of preliminary piles, have been reviewed without objection by the Project Manager.

17.6.2 Prevention of Damage due to Piling Works

(a) Piling works shall not damage any structure, utility service or previously

installed pile. The position of existing utilities shall be determined and underground utilities adjacent to the piles shall be exposed or otherwise accurately located before piling works start.

(b) All necessary measures shall be taken to minimise the settlement of the

ground and adjacent structures and utilities and to prevent the formation of cavities in the ground resulting from piling works.

(c) The vibrations due to piling works at previously installed piles measured in

terms of peak particle velocity shall not exceed 25 mm/s. (d) The vibrations due to piling works at other structures and installations in terms

of peak particle velocity shall not exceed the values stated in Table 17.1 or such limits imposed by the Project Manager or the Buildings Department.

(e) Instruments for monitoring purposes shall be installed as required by the

Project Manager and the Buildings Department prior to commencement of piling works.

Table 17.1 : Restrictions on Peak Particle Velocity

Type of structure or installation Peak particle velocity (mm/s)

Water retaining structures 13

Water mains 25

Passenger terminal complex 15

Sha Lo Wan directional beacon 1

For all other structures 25

17.6.3 Monitoring of Noise, Vibration, Ground Movement and Groundwater Level

(a) Measurements of noise level, vibration, ground movement and groundwater level shall be taken when piling works are being carried out, at locations and time intervals as stated in the Contract or as proposed by the Contractor and reviewed without objection by the Project Manager. Records of the measurements shall be kept on Site by the Contractor, and a copy of the records submitted to the Project Manager for review. The Contractor shall submit a copy of the records to the Buildings Department as necessary. Arrangements for installing instruments and taking measurements both inside and outside the Site shall be made by the Contractor.

(b) Measurements of noise level and vibration shall be made with instruments of a

type reviewed without objection by the Project Manager.


(c) Sufficient numbers of piezometers and survey points shall be installed to allow the changing groundwater levels and the effects on structures, utilities and previously installed piles to be measured. Measurements shall be taken at regular intervals as specified in the Contract when groundwater control is carried out and until such time as the groundwater has resumed its natural regime.

(d) The Contractor shall inform the Project Manager immediately of any

unanticipated change in measurements. (e) If the specified limits on vibration, groundwater movement or groundwater

level are exceeded, the work causing the limits to be exceeded shall be stopped immediately and particulars of proposed changes to the methods of construction shall be submitted to the Project Manager for review without objection. Work shall not recommence until the revised methods have been reviewed without objection by the Project Manager.

17.6.4 Ground Investigation for Piling Works

(a) Prior to the commencement of piling, pre-drilling of boreholes of minimum Nx size shall be sunk by a Registered Specialist Contractor (Ground Investigation Field Work) in accordance with PNAP 66, PNAP 132, PNAP 242 and all other relevant PNAPs to determine the soil and/or rock characteristics and to determine the appropriate founding level of non-displacement cast-in-situ piles.

(b) The Contractor shall ensure that the Registered Specialist Contractor (Ground

Investigation Field Work) (RSC (GIFW)) accurately logs and places cores in the correct order in specially constructed core boxes. The RSC (GIFW) shall clearly mark the corehole numbers on the cores and the boxes. Logging of cores shall be preformed by a suitably qualified person in accordance with PNAP 132. The Contractor shall notify the Project Manager before the start and at the completion of core drilling.

(c) Core logs and photographic records of cores shall be submitted to the Project

Manager for review within 7 days of completion of the drilling and shall be in a format suitable for submission to Buildings Department.

(d) The Contractor shall store the cores on Site during the Contract and shall

relocate or dispose of the cores and boxes as directed by the Project Manager.

(e) Unless otherwise stated in this section, drilling for ground investigation for

piling works shall be carried out in accordance with the requirements of Section 8 of this General Materials and Workmanship Specification.

(f) Soil samples and rock samples shall be taken by the Contractor from pile

excavations for visual inspection and testing. The method of sampling and testing shall be as stated in Section 8 of this General Materials and Workmanship Specification.


17.6.5 Founding Levels and Obstructions

(a) Prior to commencement of piling founded on rock, pre-boring should be carried out by a RSC (GIFW), such that the quality of the founding rock can be identified and the appropriate founding levels can be determined.

(b) Pre-boring

(i) The RSC (GIFW) shall pre-bore each pile location in accordance with PNAP 66 and the cores shall be minimum Nx size.

(ii) The RSC (GIFW) shall accurately log and place the cores in the correct

order in properly constructed core boxes supplied by the RSC (GIFW) and clearly mark the corehole numbers on the cores and boxes. The logging of the core shall be carried out by a suitably qualified person in accordance with PNAP 132 and the Contractor shall notify the Project Manager before the start and at the completion of core drilling.

(iii) Core logs and a photographic record of all cores shall be submitted to

the Project Manager for review without objection within seven (7) days of completion of core drilling, in a format suitable for submission to Buildings Department.

(iv) The Contractor shall store the cores on Site during the Contract and shall relocate or dispose of these cores and boxes as directed by the Project Manager.

(c) Pile shafts shall be excavated to founding levels in accordance with founding

criteria shown on the Employer's Drawings. This shall be established at each pile location by means of the site investigation pre-bore as specified in Clause 17.6.5(b)(i).

(d) Unless otherwise stated in the Contract, the pile base shall be levelled and

shall fully penetrate the founding stratum in the case where it is on an inclined plane.

(e) The Contractor shall notify the Project Manager immediately the pile founding

level is reached. The Contractor shall also submit, for the Project Manager’s review, a sample of the material taken from the arisings at the proposed pile founding level.

(f) Unless otherwise stated in the Contract, bored cast-in-situ piles shall be

founded on and continue into rock in accordance with the founding criteria shown on the Employer’s Drawings, or for a minimum depth of 800 mm, whichever is the greater.

(g) Obstructions are objects encountered during installation of piles that impede

or stop the pile being installed in accordance with the founding criteria shown on the Employer’s Drawings or specified strata. Obstructions shall be broken out or drilled through to enable the pile to be installed in accordance with the founding criteria shown on the Employer’s Drawings or specified strata.


17.6.6 Preliminary Piles

(a) Preliminary piles shall be constructed using the materials and methods of construction proposed for the working piles and which have been submitted to the Project Manager for review without objection. The installation of preliminary piles shall be as follows:

(i) drill a borehole adjacent to the proposed location of each preliminary

pile, before it is driven, to determine the geotechnical conditions;

(ii) install the piles at a location outside the permanent structure and to the anticipated founding depth;

(iii) test the preliminary pile by “Pile Driving Analyser” with CAPWAP

analysis after installation to the founding depth reviewed without objection by the Project Manager;

(iv) carry out loading testing on the preliminary piles in accordance with

PNAP 66 and PNAP 242 immediately after driving to determine the ultimate shaft friction and end bearing capacity of each of the piles; and

(v) cut off each preliminary pile two metres below the finished ground level,

or as directed by the Project Manager, after completion of the loading test.

(b) The relevant piling works shall not commence until the construction, testing

and records of the preliminary piles have been reviewed without objection by the Project Manager.

17.6.7 Support for Driven Piles

(a) Driven piles shall be supported and restrained by means of leaders, trestles, temporary supports or other guide arrangements in such a manner that :

(i) the piles are maintained in position and alignment;

(ii) the piles are not loosened in the ground; and

(iii) damage resulting from oscillation, vibration or movement of free-

standing piles does not occur. (b) The supports and restraints shall be maintained at all times during driving and

until the piles are self supporting. 17.6.8 Followers

(a) Followers or long dollies shall not be used unless reviewed without objection

by the Project Manager and permitted by the Buildings Department. If permitted, the set shall be revised by the Contractor and submitted to the Project Manager in a format suitable for submission to the Buildings Department for review, to allow for the reduction in effectiveness of the hammer blows.

(b) Whenever followers are used, the Contractor shall assess the energy

reduction factor of each follower for each pile size and submit the calculations to the Project Manager, in a format suitable for submission to the Buildings Department, for review without objection.


(c) The energy reduction factor of the follower shall be taken as :-

=

Energy imparted to the pile immediately after the introduction of follower Energy imparted to the pile immediately before the introduction of follower

(d) The energy reduction factor for every combination of follower and pile size

shall be determined by averaging the results of 5 sets of dynamic pile tests performed at or near to the set of 5 different piles of the same size.

17.6.9 Marking of Piles

Piles, including temporary and permanent casings, shall be marked at 1 m intervals before pitching.

17.6.10 Driving Piles

(a) Each pile, other than sheet piles, shall be driven without interruption until the required depth or set has been achieved. If a minimum depth of penetration is stated in the Contract, the Contractor shall submit to the Project Manager for review his proposals for achieving this requirement. The Contractor shall ensure that the minimum penetration and set are achieved without causing damage to the pile.

(b) The sequence and method of driving piles shall minimise the detrimental

effects of heave and lateral displacement of the ground and cause the least possible displacement to previously installed piles. The Contractor shall drive piles from the centre of the pile group and work outwards. Piles, including casings, shall not be driven within a centre to centre distance of 3 m or five times the diameter of the pile or casing, whichever is less, from an unfilled excavation or from an uncased concrete pile which has been cast for less than 48 hours.

(c) The Contractor shall inform the Project Manager without delay of any sudden

change in driving characteristics. The Contractor shall investigate the cause of any sudden change in driving characteristics and further driving shall not continue until these investigations have been completed and the results reviewed without objection by the Project Manager

17.6.11 Precast Concrete Piles

The use of precast concrete piles is not permitted. 17.6.12 Displaced Piles

Piles which have been displaced as a result of driving adjacent piles shall be corrected. Particulars of the method of correction and measures to be taken to avoid displacement in subsequent driving shall be submitted to the Project Manager for review without objection.


17.6.13 Re-drive Checks

(a) Re-drive checks shall be carried out on all preliminary piles and as directed by the Project Manager. The pile driving formula proposed by the Contractor shall be revised if the final set on re-driving is more than the final set achieved during the initial driving.

(b) Preliminary piles which fail the re-drive check shall be deemed unacceptable.

Additional preliminary piles shall be proposed together with the revised pile driving formula for the review without objection of the Project Manager.

(c) No re-drive checks shall be carried out within 24 hours of completion of first

driving. 17.6.14 Lengthening Driven Piles

(a) Pile Joints

The strength of piles at joints shall not be less than the strength at any normal section of the pile. Lengthened piles shall not be driven until the joint has developed the designed strength. Pile joints shall be tested as stated in the Contract.

(b) Splicing and Welding

(i) Splicing of H-piles shall be carried out in accordance with the requirements shown on the Employer’s Drawings.

(ii) Welding for splicing of H-piles shall be carried out in accordance with

Section 22 of this General Materials and Workmanship Specification. (iii) Testing of welding for splicing of H-piles shall be carried out in

accordance with Sections 17.7.8(a) and 17.7.8(b).

(iv) Piles shall be accurately located and aligned during welding. The Contractor shall ensure that the straightness of the complete pile shall not deviate by more than 3 mm along a 3 m straight edge or by 1 in 1,000 overall.

17.6.15 Measurement of Set and Working Load Capacity of Driven Piles

(a) Set shall be measured for each driven pile in the presence of the Project Manager and reviewed without objection by the Project Manager. The final set shall be measured as either:

(i) penetration per 10 blows; or

(ii) the number of blows required to produce 25 mm penetration.

(b) If driving is interrupted for more than 30 minutes, set shall not be measured

after driving restarts until at least 20 blows of the same driving energy as at final set have been struck.


(c) When final set is measured:

(i) the exposed part of the pile shall be in good condition without damage or distortion;

(ii) the dolly and packing shall be in sound condition;

(iii) the final hammer blows shall be in line with the axis of the pile and the

impact surfaces shall be flat and at right angles to the axes of the pile and hammer; and

(iv) the hammer shall be in good condition and operating correctly.

(d) The temporary compression of each driven pile shall be measured.

(e) The Contractor shall notify the Project Manager at least 1 hour before final set

and temporary compression are to be measured.

(f) Piles shall be driven by hydraulic hammer. The Contractor shall assess the pile working load capacity according to a pile-driving formula (e.g. the modified Hiley Formula with the adoption of a single efficiency factor for hydraulic hammer, Kh, multiplied by the impact energy. The value of Kh shall be reviewed without objection by the Project Manager and the Buildings Department). The factor of safety shall not be less than two (2) for ultimate driving resistance against working load.

(g) The pile-driving formula shall be calibrated against load tests carried out on

preliminary piles and checked as other piles are tested. The pile-driving formula and correlation with test loading data shall be submitted to the Project Manager for review without objection prior to carrying out piling works other than preliminary piles

(h) The pile shall not be considered to have attained the theoretical calculated

safe loading capacity should the penetration at final set be in excess of the value reviewed without objection by the Project Manager.

(i) The temporary compression of the driving cap shall be taken as not less than 7.5 mm when hardwood packing at the pile head and in the dolly are 100 mm thick.

17.6.16 Excavation for Cast-In-Situ Piles

(a) Excavation for cast-in-situ concrete piles shall be carried out by mechanical methods; blasting and compressed air shall not be used.

(b) The stability of excavation for cast-in-situ concrete piles shall be maintained

where necessary by:

(i) temporary casings;

(ii) permanent casings; or

(iii) a thixotropic slurry containing bentonite or other similar agent reviewed without objection by the Project Manager.

(c) The bottom of casings shall be kept sufficiently deep to prevent the flow of soil

into the casing.


(d) Permanent casings shall not be used within temporary casings.

(e) Drilling fluids shall not be used.

(f) Where an enlarged base of a cast-in-situ concrete pile is required, this shall be formed by under-reaming with reverse circulation heads.

17.6.17 Excavation for Barrettes

(a) Excavation for barrettes shall be carried out by mechanical methods; blasting shall not be used.

(b) The stability of excavations for barrettes shall be maintained by a thixotropic

slurry containing bentonite or other similar agent reviewed without objection by the Project Manager.

(c) The height of guide walls for barrettes shall be such that the head of slurry

shall ensure the stability of excavations and prevent movement of the adjacent ground in excess of that specified in the Contract. The position, alignment and level of guide walls shall be checked at regular intervals and submitted for review without objection by the Project Manager.

17.6.18 Excavation for Minipiles

The Contractor shall install minipiles without the use of bentonite slurry or other drilling muds. The stability of excavations for minipiles shall be maintained where necessary by permanent casings which shall :

(a) be manufactured from Grade 43 mild steel;

(b) have a minimum thickness of 4.5 mm; (c) have an internal diameter of not less than the finished pile diameter shown or

as scheduled on the Employer’s Drawings; (d) be free from distortion and internal projections throughout the whole length

which might prevent the proper formation of the piles; and (e) be of uniform cross-section throughout the whole length.

17.6.19 Design and Construction of Minipiles

The design and construction of minipiles shall be in accordance with guidelines provided in PNAP 66, PNAP 242 and all other relevant PNAPs.

17.6.20 Grouting Trials for Minipiles

Grouting trials shall be carried out to demonstrate accurate control of water/cement ratio, consistency of mixing, satisfactory workability and achievement of strength requirements. The trial shall be carried out on one minipile which is considered representative of those which are to be constructed in the Permanent Works and at a location reviewed without objection by the Project Manager.


17.6.21 Inclination of Piles

The Contractor shall check the inclination of every inclined pile at each stage, during installation. The Contractor shall arrange for a number of piles, as directed by the Project Manger, to be checked by the use of an inclinometer or other method reviewed without objection by the Project Manager, before grouting. The Contractor shall record the inclination and orientations of the holes and submit the records to the Project Manager for review.

17.6.22 Excavation for Socketted Steel H-piles

(a) The prebored holes shall be large enough to allow a minimum cover of 40 mm to the steel H-piles.

(b) A temporary casing, the quality of which has been reviewed without objection,

shall be provided in the pre-boring process down to at least 500 mm or such depth as required, below rockhead level, to prevent soil from falling into the pre-bored hole.

(c) Before the steel H-pile is inserted in the pre-bored hole, the hole should be

cleaned with air flushing to ensure that is free from debris and soil. (d) Extraction of the temporary casing shall be carried out while the grout is

sufficiently workable to ensure that the grout is not lifted with the casing. A vibratory extractor, which has been reviewed without objection by the Project Manager, may be used.

17.6.23 Construction using Bentonite Slurry

(a) Excavation using bentonite slurry

(i) Excavations for piles using bentonite slurry shall be filled with slurry from the time that excavation commences until concreting is complete. The slurry shall be maintained at a level of at least 1 m above the level of the external groundwater and such that the slurry pressure exceeds the pressure exerted by the soil and ground water.

(ii) If there is a loss of bentonite slurry from the excavation which is

sufficient to result in a lack of stability, the excavation shall be immediately filled with material previously reviewed without objection by the Project Manager. The cause of the loss of slurry shall be investigated and excavation shall not recommence until remedial action, reviewed without objection by the Project Manager, has been taken.

(b) Mixing of bentonite slurry

(i) Bentonite shall be thoroughly mixed with water in a colloidal mixer. The

water for bentonite shall be clean, uncontaminated and from a source reviewed without objection by the Project Manager. The Contractor shall test the water in accordance with the requirements of Section 20.8.3. The water shall be at a temperature of at least 5oC. The temperature of the bentonite slurry shall be at least 5oC when supplied to the excavation.


(ii) If the groundwater is excessively saline or chemically contaminated, the bentonite shall be pre-hydrated or the bentonite slurry shall be modified such that the slurry is suitable to support the excavation.

(c) Disposal of benetonite slurry

Any remaining bentonite slurry shall be removed from the Site and disposed in

accordance with Section 7. 17.6.24 Fixing Reinforcement for Piles

(a) Fixing reinforcement for large diameter bored piles and continuous flight augur piles

Prefabricated reinforcement cages for piles shall be marked and fitted with spacers to ensure that the cage is correctly orientated and positioned within the pile.

(b) Fixing reinforcement to minipiles

Reinforcement shall be lengthened by staggering the couplers using methods reviewed without objection by the Project Manager. Each reinforcement bar shall be separated by spacers at regular intervals.

17.6.25 Cleaning and Drying Excavations for Piles

(a) The bases of excavations for piles shall be cleaned by air lifting before concrete is placed. If excavation is carried out under water, cleaning shall continue until the water is clear and free from particles of soil. Measures shall be taken to prevent the accumulation of silt and other material at the base of the excavation.

(b) If the excavation for piles is supported by bentonite slurry:

(i) the Contractor shall take measures to remove all silt or other material at

the base of the boring. The Contractor shall remove heavily contaminated bentonite suspension, which could impair the free flow of concrete from the pipe of the tremie, from the bottom of the hole; and

(ii) the Contractor shall take a sample of the bentonite suspension from the

base of the boring using a sampling device reviewed without objection by the Project Manager. If the specific gravity of the suspension exceeds 1.25 the placing of concrete shall not proceed, and the bentonite shall be replaced.

(c) Provided the rate of ingress of water does not exceed 0.3 l/s, the base of

excavations for piles shall be dried immediately before concrete is placed.


17.6.26 Placing Concrete in Piles

(a) Each pile shall be concreted as soon as practicable. Concrete shall be placed without interruption until the complete pile is concreted.

(b) In the event that excavations for piles are supported by bentonite slurry or if

the rate of ingress of water exceeds 0.3 l/s, the Contractor shall comply with the following :

(i) concrete shall be placed by tremie;

(ii) the hopper and pipe of the tremie shall be clean and watertight

throughout. The pipe shall extend to the base of the boring and a sliding plug or barrier shall be placed in the pipe to prevent direct contact between the first charge of concrete in the pipe of the tremie and the water or drilling fluid. After the first charge of concrete the pipe shall at all times penetrate the concrete which has previously been placed and shall not be withdrawn from the concrete until completion of the concreting. Sufficient concrete shall be maintained within the pipe to ensure that the pressure from it exceeds that from the water or drilling fluid. The internal diameter of the pipe of the tremie shall be not less than 150 mm for concrete made with 20 mm aggregate. It shall be so designed that external projections are minimized, allowing the tremie to pass through reinforcing cages without causing damage. The internal face of the pipe of the tremie shall be free from projections;

(iii) the minimum cement content of the concrete shall be 375 kg/m3;

(iv) the level of the top of the concrete in piles shall be at least 1 m above

the specified cut-off level; and

(v) if the top of the guide wall of barrettes is at the specified cut-off level, concrete shall continue to be placed until the top of the pile is free from contamination.

(c) Operations which in the opinion of the Project Manager are likely to disturb or

affect the concrete or placing of the concrete shall not be carried out. (d) For piles concreted in dry conditions, the concreted level shall be not less than

150 mm and not more than 500 mm above the specified cut-off level. For piles cast using tremie concrete, the concrete level shall be not less than 1 m and not more than 2 m above the specified cut-off level.

(e) The Contractor shall trim back the concrete of all piles to final cut-off level.

Trimming back shall be carried out at least 7 days after placing the concrete. 17.6.27 Grouting for Piling Works

(a) Grout material shall be mixed by weight batching. The amount of water used shall be measured by a calibrated flowmeter or a measuring tank. The mixing time in high speed mixers shall be suitable for the type of mixer used. After mixing, the grout shall be continuously agitated in a holding tank and screened before injection.

(b) Before grouting, the bottom of the hole shall be flushed by high pressure air.


(c) The grout intake volume should be measured with a flowmeter accurate to ±1 litre. The Contractor shall calibrate the flowmeter and submit a calibration report to the Project Manager 7 days before trial mix of grout is made. Each pile shall be cast-in one continuous operation and under no circumstances shall a pile be left partially grouted.

17.6.28 Removal of Temporary Casings to Piles

(a) A sufficient quantity of concrete shall be maintained within temporary casings being withdrawn to ensure that the pressure from external water or soil is exceeded and that the pile is not reduced in section or contaminated.

(b) Temporary casings in contact with concrete and not withdrawn before the

initial set of the concrete shall be left in place. (c) The Contractor shall take precautions reviewed without objection by the

Project Manager in all cases where excess heads of water or drilling fluid could be caused as the casing is withdrawn due to the displacement of water or fluid by the concrete as it flows into its final position against the walls of the shaft.

(d) Where two or more discontinuous lengths of casing (double casing) are used in the construction, the proposed method of working shall be reviewed without objection by the Project Manager.

17.6.29 Empty Bores above Piles

Empty bores and shafts which remain above the pile after concrete has been placed shall be temporarily protected or filled with material, of a type which has been reviewed without objection by the Project Manager as soon as practicable.

17.6.30 Tolerances: Steel Bearing Piles

Dimensional tolerances of steel bearing pile sections shall comply with the BS 4360, BS 5950 and BS 5400 as stated in Section 22.3.1. Fabrication tolerances for steel bearing piles and related steelwork shall comply with BS 5950:Part 2.

17.6.31 Tolerances: Pile Installation

(a) Piles, including mini-piles, shall be installed to within the tolerances stated in Table 17.2.

(b) Piles which do not comply with the specified tolerances shall not be forcibly

corrected.

Table 17.2: Tolerances of Installed Piles

Description Tolerance Deviation from specified position in plan, measured at cut-off level 75 mm Deviation from vertical (a) all piles except bored piles (b) bored piles

1 in 75 1 in 300

Deviation of raking piles from specified batter Deviation from specified cut-off level

1 in 25 -25 mm, +0

The diameter of cast in-situ piles shall be at least 97% of the specified diameter at all points.


17.6.32 Remedial Works to Out of Tolerance Piles

(a) In the event that one or more piles are identified as being outside the tolerances for installed piles, the Contractor shall submit proposals for remedial works to the Project Manager for review without objection, in a format suitable for submission to the Buildings Department, within 10 days of the completion of the piling work survey.

(b) The Contractor’s remedial works proposals shall include design calculations

and Contractor’s Drawings prepared by a registered structural engineer. The proposals shall show the extent of additional reinforcement necessary such that stresses in the pile and related structure are within acceptable limits.

(c) Remedial works shall be carried out upon approval and consent by the

Buildings Department and review without objection by the Project Manager, prior to commencing any works over the affected pile.

17.7 INSPECTION TESTING AND COMMISSIONING 17.7.1 Quality Supervision for Piling Works

The Contractor shall comply with the requirements for quality supervision in accordance with PNAP 242.

17.7.2 Inspection of Piling Works

(a) Where pile bores or excavations are retained by bentonite slurry, the Contractor shall arrange Koden tests to be carried out on each pile by an independent testing body reviewed without objection by the Project Manager. The Contractor shall submit the test report to the Project Manager prior to placing concrete in piles.

(b) The Contractor shall notify the Project Manager before placing concrete in

piles. 17.7.3 Inspection of Installed Piles

(a) If directed by the Project Manager, installed piles shall be exposed for inspection or testing. Excavations for exposing piles shall be of a depth reviewed without objection by the Project Manager, and the face of the excavation shall be at least 750 mm from the face of the pile. The excavation shall be maintained in a stable condition and kept free from water.

(b) The surface of the pile shall be washed clean of all silt, mud or other adhering materials to permit inspection.

(c) After inspection, excavations for exposing piles shall be filled using suitable fill

material, of a type reviewed without objection by the Project Manager, which shall be compacted to obtain a relative compaction of at least 95% above the groundwater table.


17.7.4 Post Construction Proof Drilling

(a) Post construction proof drilling shall be carried out after the construction of piles in accordance with PNAP 66, PNAP 132 and PNAP 242.

(b) For large diameter bored piles and barrettes where core-drilling at the

concrete/rock interface is to be carried out at each pile, the concrete shall be in contact with rock at the interface. If imperfections such as a thin layer of sediment, segregated concrete, honeycomb are found, the Contractor shall submit remedial proposals to the Project Manager, for review without objection, in a format suitable for submission to the Buildings Department.

17.7.5 Testing: Load Tests on Piles

(a) Testing: load tests on piles

(i) The number of piles to be tested by load testing shall be as stated in the Contract or as required by the Buildings Department, whichever is the greater.

(ii) The piles shall be tested to determine the settlement of the pile under

load. Testing shall be carried out in accordance with the method of testing as stated in PNAP 66 and requirements imposed by the Buildings Department.

(iii) Piles shall not be tested until the concrete or grout has attained sufficient

strength to withstand the tests. The Contractor shall notify the Project Manager 7 days prior to the commencement of the test.

(iv) Records of pile load tests shall be kept by the Contractor and submitted to the Project Manager within 24 hours of each test completion. The records shall be kept on the standard forms as shown in Appendix A17.6.

(b) Compliance criteria: load tests on piles

Unless otherwise stated in the Contract, the results of load tests on piles shall comply with criteria described in PNAP 66 and requirements imposed by the Buildings Department.

(c) Non-compliance: load tests on piles

If the result of any load test on piles does not comply with the specified requirements for settlement, the Contractor shall submit remedial proposals to the Project Manager for review without objection. In the event the remedial proposal involves any change of design, the design calculations and Contractor’s Drawings shall be prepared by a registered structural engineer and shall be submitted to the Project Manager for onward submission to Buildings Department for approval. No remedial works shall be undertaken, before review without objection by the Project Manager and approval by the Buildings Department.


17.7.6 Testing: Concrete Cores from Piles

(a) Samples : concrete cores from piles

(i) The number of concrete cores to be provided for testing from concrete piles shall be the larger of, the number required to satisfy the Buildings Department, and the number stated in the Contract. The positions from which the cores are taken shall be as directed by the Project Manager.

(ii) Concrete cores shall be 100 mm diameter.

(iii) The method of taking concrete cores shall be in accordance with CS1.

(iv) Holes formed by taking concrete cores from piles shall be reinstated

using non-shrink concrete or grout, of the same characteristic compressive strength as the concrete of the pile and reviewed without objection by the Project Manager.

(b) Testing: concrete cores from piles

(i) Each concrete core from a pile shall be inspected for evidence of

segregation of the constituents and for the presence of voids. Specimens selected from each core shall be tested to determine the compressive strength.

(ii) The method of preparing, inspecting and testing concrete cores shall be

as stated in Section 20.8.17.

(c) Compliance criteria: concrete cores from piles

The compliance criteria for concrete cores from piles shall be as stated in PNAP 66 and Section 20.8.18.

(d) Non-compliance: concrete cores from piles

(i) If the result of any test on a concrete core from a pile does not comply

with PNAP 66 and/or Clause 20.8.18, additional cores shall be taken from the same pile and additional tests shall be carried out.

(ii) Additional concrete cores shall be 100 mm diameter for concrete of 20

mm nominal maximum aggregate size and 150 mm diameter for concrete of 40 mm nominal maximum aggregate size. The number of additional cores shall be as directed by the Project Manager.

(iii) If the result of any additional test does not comply with the compliance

criteria for concrete cores the Contractor shall submit remedial proposals to the Project Manager for review without objection. The number of additional piles and additional tests shall be as directed by the Project Manager.


17.7.7 Testing: Non-destructive Tests on Welds in Piles

(a) Testing: non-destructive tests on welds in piles

(i) The number and type of non-destructive tests on welds in piles shall be as stated in the Contract or as required by the Buildings Department, whichever is the greater.

(ii) Radiographic tests shall comply with BS 2600:Part 1 and ultrasonic tests

shall comply with BS 3923:Part 2.

(b) Non-compliance : non-destructive tests on welds in piles

If the result of any test on a weld in a pile does not comply with the specified requirements, the complete weld shall be cut out, the joint shall be re-welded and the weld shall be retested.

17.7.8 Testing: Integrity Tests

(a) Testing: sonic and vibration tests on piles

(i) In all bored cast-in-situ piles excavated by machine the Contractor shall install three 50 mm and one 150 mm internal diameter steel tubes securely tied to the reinforcement cage. The tubes shall be extended to the full depth of the pile and terminate above the finished concrete level. The tubes shall be watertight, corrosion free, continuous with sealed joints and with the top and bottom sealed with a 2.0 mm thick steel plate welded to the tube. The tubes shall be equally spaced around the piles. The Contractor shall submit details of the proposed method of installation of the tubes for the Project Manager's review without objection.

(ii) The Contractor shall carry out sonic tests at cast-in-situ pile at locations

reviewed without objection by the Project Manager to verify the integrity and homogeneity of the pile.

(iii) The Contractor shall carry out vibration tests at all cast-in-situ piles

which have not been sonic tested to verify the integrity and homogeneity of these piles.

(iv) Sonic and vibration testing shall be carried out by an independent testing

company. (v) The Contractor shall submit the details of the proposed independent

testing company and the proposed procedures for sonic and vibration testing to the Project Manager for review without objection.

(vi) All reports, and photographic traces from sonic and vibration tests shall

be submitted to the Project Manager for review without objection within 48 hours of completion the test.

(vii) All tubes shall be cut-off flush with the concrete and filled with non-shrink grout having the same characteristic compressive strength as the concrete on completion of all testing.


(b) Non-compliance : sonic and vibration testing

If the results of any sonic or vibration test indicate that the pile does not comply with the specified requirements or indicate any weakness or discontinuity in the pile, additional tests shall be carried out by the Contractor to confirm that the quality and bearing capacity of the pile satisfy the requirements of the Contract and the Buildings Department. In the event that the additional tests show that the pile does not comply, the Contractor shall propose remedial measures for review without objection by the Project Manager.

17.7.9 Testing: Bentonite Slurry

(a) Samples: bentonite slurry

(i) Samples of bentonite slurry shall be provided for testing at a frequency reviewed without objection by the Project Manager. Samples for testing to determine the density of the slurry shall be provided each day. A sample of bentonite slurry taken from the base of the excavation shall be tested to determine the density of the slurry before placing of concrete.

(ii) The method of sampling and the sampling apparatus shall be reviewed

without objection by the Project Manager.

(b) Testing: bentonite slurry

(i) Each sample of bentonite slurry shall be tested to determine the density, viscosity, shear strength and pH value.

(ii) The method of testing shall be as stated in Table 17.3.

(iii) The measuring device for testing density shall be readable and accurate

to ±0.005 g/mL.

(iv) Samples to be tested for viscosity using the Fann viscometer shall be screened before testing using a 300 μm BS test sieve.

(c) Compliance criteria : bentonite slurry

(i) The results of tests on bentonite slurry shall be as stated in Table 17.3.

(ii) Tests to determine the shear strength and pH value shall be

discontinued if the results of tests indicate that a consistent working pattern has been established, taking account of the mixing process, blending of freshly mixed and previously used slurry and processes used to remove impurities from previously used slurry. If there is a subsequent change in the established working pattern, the tests to determine shear strength and pH value shall be re-introduced.


(d) Non-compliance : bentonite slurry

If the results of tests for density and viscosity do not comply with the specified requirements, or if the results of tests for shear strength or pH value do not indicate a consistent working pattern, the bentonite slurry shall be deemed unsuitable for the work and concrete shall not be placed in the slurry. The slurry shall be replaced or its composition adjusted before concrete is placed.

Table 17.3: Properties of Bentonite Slurry and Methods of Testing

Property at 20°C Test Results Method of Testing Density as supplied to excavation ≤ 1.10 g/mL Mud density balance Density at base of excavation before placing concrete

≤ 1.25 g/mL Mud density balance

Viscosity 30 – 50 seconds Marsh cone method or ≤ 0.02 Pa.s Fann viscometer

Shear strength (10 minute gel strength)

1.4 – 10 N/m2 Shearometer or 4 – 40 N/m2 Fann viscometer

pH value 8 – 12 pH indicator paper strips or electrical pH meter

17.7.10 Testing of Grout

(a) Definition of batch

A ‘batch’ of grout is any quantity of grout used for grouting in one continuous operation in one day.

(b) Test for bleeding and free expansion

(i) One sample of grout from each batch shall be provided for testing not

more than 30 minutes after mixing and protected from changes in moisture content before tests are carried out.

(ii) Each sample shall be divided into 3. Each third shall be placed in a

covered cylinder with a diameter of 100 ± 10 mm to a depth of 100 ± 5 mm and the amount of bleeding and free expansion shall be measured by a scale fixed to the outside of the cylinder.

(iii) If the result of any test for the amount of bleeding or free expansion of

the grout does not comply with the specified requirements, proposed changes to the materials, grout mix or method of production shall be submitted to the Project Manager for review without objection.

(c) Flow cone efflux test

(i) One sample from each batch shall be taken and tested in accordance

with ASTM C939-94 to determine the “Flow Cone Efflux” time.

(ii) Grout mixes containing additives with an efflux time of less than 15 seconds shall be rejected.


(d) Test for crushing strength

(i) One sample of the grout shall be taken from each grouting operation after mixing and protected from changes in moisture content before making test cubes.

(ii) Cubes shall be prepared using 100 mm cube moulds.

(iii) Strength compliance requirements shall comply with Section 20.8.14.

17.7.11 Testing: Dynamic Pile Test

(a) Testing: dynamic pile test

(i) In addition to load tests on piles, dynamic testing on driven piles shall be carried out by the Contractor. The dynamic pile test is a test applied to the pile by means of a falling weight, hammer or other percussive device. The response of the pile to the impact force is measured in terms of pile strain, acceleration and displacement. The results of the dynamic pile test shall allow a determination to be made by the Contractor on the load capacity of the pile. The Contractor shall take measurements at one level on the pile surface near the pile cap.

(ii) The dynamic pile testing method shall be reviewed without objection by

the Project Manager prior to carrying out testing.

(iii) The number of dynamic pile tests shall be as stated in the Contract and the tests shall be carried out on piles selected by the Project Manager.

17.7.12 Records of Piling Works

(a) Records of piles delivered

Records of prefabricated piles shall be kept by the Contractor on Site and submitted to the Project Manager for review at the time the piles are delivered to Site. The records shall include test certificates, analyses and mill sheets for steel piles and proprietary piles.

(b) Records of pile installation

Records of pile installation shall be kept by the Contractor on Site and

submitted to the Project Manager for review without objection within 24 hours after the driving or installation of each pile has been completed. The records shall be kept on standard forms as shown in Appendices A17.2 to A17.4. The records and Form BA 14 shall be submitted to the Project Manager for onward submission to the Buildings Department upon completion of piling works.

(c) Records of bentonite slurry

Records of tests of bentonite slurry shall be kept by the Contractor on Site and

a report shall be submitted to the Project Manager at frequencies reviewed without objection by the Project Manager. The records shall be kept on standard forms as shown in Appendix A17.5.


(d) Records of load tests on piles

Records of load tests on piles shall be kept by the Contractor on Site and a report shall be submitted to the Project Manager for review without objection within 48 hours after the test has been completed. The records shall be kept on standard forms as shown in Appendix A17.6. The records shall include graphs showing load and settlement versus time, plotted in the format shown in BS 8004, Figure 15(a).

(e) Records of integrity tests on piles

Records of integrity tests on piles shall be prepared by an experienced

engineer reviewed without objection by the Project Manager and shall be kept by the Contractor on Site and a report shall be submitted to the Project Manager for review without objection within 48 hours after the test has been completed. The records shall be available to the Project Manager for inspection at all times. The report shall contain the following details:

(i) pile reference numbers;

(ii) measured pile length;

(iii) defects such as cracks, fractures or discontinuities; and

(iv) pile stiffness.

The Contractor shall submit the records to the Project Manager for onward submission to the Buildings Department.

17.7.13 Record Drawings

(a) Record drawings of installed piles shall be prepared by the Contractor and four copies shall be submitted to the Project Manager for review within 14 days of completing each group of the piles.

(b) The drawings shall include a plan showing characteristic features of the Site,

the as-constructed co-ordinates of the centre of each pile at cut-off level, the final depth and cut-off level and size of each pile as constructed and other information to the satisfaction of the Buildings Department and the Project Manager.

(c) The Contractor shall submit record drawings and Form BA 14 to certify

completion of piling works, to the Project Manager for onward submission to the Buildings Department. For the avoidance of doubt, these record drawings are in addition to the as-constructed drawings required under the Contract.


APPENDIX A17.1

DETERMINATION OF THE LOAD DEFLECTION CHARACTERISTICS OF PILES BY LOAD TEST

A17.1.1 Scope This method determines the load deflection characteristics of piles. A17.1.2 Equipment The following equipment is required:

(a) Kentledge, anchor piles or other anchorages supported or installed at suitable locations to provide adequate reactions against jacking.

(b) A load measuring device which shall consist of a load column, pressure cell,

or other appropriate system, calibrated before and after each series of tests, or whenever adjustments are made to the device, or at time intervals recommended by the manufacturer of the equipment.

(c) Four deflectometers accurate to 0.025 mm. (d) Precision levelling equipment accurate to 0.25 mm. (e) A reference frame for supporting deflectometers and providing a datum for

deflectometer measurements. (f) Working platforms. (g) Screens and protection from exposure to conditions which may affect the test. (h) Hydraulic loading equipment.

A17.1.3 Procedure: Before Testing The procedure before testing shall be as follows:

(a) The kentledge, anchor piles or other anchorages shall be installed. The centre of each anchor pile shall be at least 2 m or three times the pile diameter, whichever is greater, from the centre of the pile to be tested and from the centre of any adjacent pile.

(b) If required, the pile to be tested shall be extended from cut-off level to ground

level. The strength of piles at joints shall not be less than any normal section of the pile.

(c) A temporary square pile cap designed by the Contractor shall be constructed. (d) Working platforms, screens and protection shall be installed. (e) The reference frame shall be set up on supports which are at least 2 m or

three times the pile diameter, whichever is greater, from the test pile and anchor pile. The four deflectometers shall be mounted on the reference frame to measure the deflection of the four corners of the temporary pile cap.


A17.1.4 Procedure : Load Test The procedure for the load test shall be as follows:

(a) Preliminary piles shall be tested to not less than twice the working load of the pile. Working piles shall be tested to not less than 1.8 times working load. Reductions for group or boundary effects shall not be made in determining the test loads.

(b) Test loads shall be applied and removed in three stages as stated in Table

A17.1.1. (c) The test loads shall be applied in increments, and removed in decrements, of

25% of the working load. Increments of load shall not be applied until the rate of settlement of the pile is less than 0.1 mm in 20 minutes.

(d) The full test loads for Stage I, defined in Table A17.1.1, shall be applied in

increments and shall then be maintained for at least 24 hours after the rate of settlement has reduced to less than 0.1 mm per hour. The test loads shall be removed in decrements and the recovery of the pile determined before loading is resumed.

(e) The procedure stated in Clause A17.1.4 (d) shall be repeated for Stage II,

defined in Table A17.1.1, loading. (f) The procedure stated in Clause A17.1.4 (d) shall be repeated for Stage III,

defined in Table A17.1.1, loading unless the Project Manager directs the loading to be maintained for a longer period.

(g) The settlement of the pile shall be measured at hourly intervals. The

settlement of the pile under each increment and decrement of loading shall be measured. The exact times at which increments are applied and decrements are removed shall be recorded. Settlements shall be measured and times shall be recorded in the presence of the Project Manager.

(h) The level of the reference beam shall be checked at regular intervals, as

reviewed without objection by the Project Manager during the test. Table A17.1.1 : Test Loading Stages

Stages Test load I 25% of max. test load II 50% of max. test load III 100% of max. test load

A17.1.5 Procedure: After Testing After testing, equipment shall be removed, temporary pile caps shall be demolished

and pile extensions shall be removed to cut-off level. Anchor piles shall be withdrawn.



(a) The loads applied to the nearest 0.05 t. (b) The settlement of the pile to the nearest 0.05 mm at hourly intervals and

under each increment and decrement of loading. (c) The exact times at which increments were applied and decrements removed. (d) The levels of the reference beam, to the nearest 0.05 mm.


APPENDIX A17.2

PILE DRIVING RECORD

(Prefabricated Steel and Driven Cast-in-place Piles) Contract No. Title Contractor Pile data Reference No. Location Type Size Rake For steel piles; Length ____________________________________ Drive system data Hammer: type mass kg drop (at set) mm rated energy kJ Helmet, dolly & anvil : type mass kg Packing : type condition thickness mm Levels Commencing ground/sea bed* level (PD/CD)* Depth of overburden/height of working platform above ground/sea bed level Reference working level/platform level* Date & Time

Drop (m)

Depth penetrated (m)

No. of blows+

Cumulative No. of blows

Length of individual segments, location of splices and tests carried out

Remarks (State details of obstruction, delays, interruptions and location of concrete samples++)

+ per 0.25 m for top 3.0 m of pile ++ for cast in place piles (*delete as appropriate)


PILE DRIVING RECORD

(Prefabricated Steel and Driven Cast-in-place Piles) Temporary compression record (on graph paper graduated in millimetres to be pasted in

space below)

Final penetration depth mm Top of pile level Temporary compression mm Cut off level Final set mm/last 10 blows Pile head level or blows/25 mm Final toe level Deviation from plumb or rake 1 in Deviation at cut-off level x-x mm y-y mm For driven cast-in place piles: Length of temporary Length of permanent Length of cage casing casing reinf. m Concrete grade Date of concreting Theoretical volume of concrete required m

3

Actual volume of concrete placed m

3

Reported by Verified by Contractor's Representative Project Manager's Representative Date Date (* delete as appropriate)


APPENDIX A17.3

PILE RECORDS

(Bored Cast-in-place Piles) Contract No. Title Contractor Pile data Reference No. Location Type Diameter mm Design Length mm Rake 1 in Bore hole record Commencing ground/sea bed* level (P.D./C.D.)* Depth of overburden/height of working platform above ground/sea bed level m Casing/drilling fluid* type Reference working level/platform level* Date & Time

Depth penetrated

Details of strata penetrated/ground water level

Details of soil testing, proving of bedrock and under-ream

Remarks (State details of obstruction, delays interruptions, and location of concrete samples)

Deviation from plumb or rake 1 in Deviation at cut-off level x-x mm y-y mm Length of temporary casing m Length of permanent casing m (*delete as appropriate)


PILE RECORDS

(Bored Cast-in-place Piles)

Bore hole condition prior to concreting Bottom visible/invisible*Measured depth of bore m Depth of water/drilling fluid* m Damage and debris observations Concrete record Concreting in dry/by tremie* Water inflow rate litres/second Concrete grade Slump Actual concreted level Cut off level Lt

Overall __ = % La Length of cage reinforcement m Date & Time

Delivery note No./ Truck load No.

Quantity (m3)

Theore- tical length filled Lt(m)

Actual Length Placed La (m)

Lt %La

Cumulative length placed (m)

Remarks (Interruptions in placing, cause of excessive Lt ± %, Location of

La concrete samples, Ref. No. of cubes taken, etc.)

Reported by Verified by Contractor's Representative Project Manager's Representative Date Date Note : The Project Manager shall be informed of any deviation greater than ± 10%

from the expected (theoretical) level of concrete placed. (* delete as appropriate)


APPENDIX A17.4

PILE RECORDS

(Barrettes)

Contractor No. Title Contractor Pile data Reference No. Location Size of barrette Shape Design Length m Excavation data Commencing ground level (PD) Depth of overburden m Guide wall levels: top bottom Date Depth

reached (m)

Details of Strata penetrated/surrounding ground water level

Details of soil testing, proving of bedrock, and under-ream

Remarks (State details of obstructions, interruptions and delays)

Deviation from plumb 1 in Deviation at cut-off level x-x mm y-y mm Base level of excavation m Depth of base from top of guide wall m


PILE RECORDS

(Barrettes)

Concrete record Concrete grade Slump Actual concreted level Cut off level Lt

Overall __ = % La Length of cage reinforcement m Date & Time

Delivery note No./ Truck load No.

Quantity (m

3)

Theore- tical length filled Lt (m)

Actual Length Placed La (m)

Lt %

La

Cumulative length placed (m)

Remarks (Interruptions in placing, cause of excessive Lt ± %, Location of

La concrete samples, Ref. No. of cubes taken, etc.)

Report by Verified by Contractor's Representative Project Manager's Representative Date Date Note The Project Manager shall be informed of any deviation greater than ± 10% from the

expected (theoretical) level of concrete placed. (*delete as appropriate)


APPENDIX A17.5

BENTONITE SLURRY RECORDS

Contract No. Title Contractor Sample data Ref. No. of pile Location Sources of test sample: (a) freshly mixed slurry* (b) as supplied to excavation* (c) from bottom of excavation prior to placing concrete* Date & time of sampling Test Method and

Apparatus Used

Test Result Density (g/mL) Viscosity (seconds) pH Sand Content (%) Fluid Loss (mL) Temperature (°C)

Remarks : - Reported by Verified by Contractor's Representative Project Manager's Representative Date Date (* delete as appropriate)


APPENDIX A17.6

PILE LOAD TEST RECORD

(Test Result)

Contract No. Title Contractor Pile data Reference No. Location Type Size Pile dia/diagonal width (D) Gross pile length (Lp) Sectional area (A) Young's modulus (E) Testing data Design working load (P) Test load (Q) = 2 (P) Pressure gauge No. Calibration Certificate ref. Date Dial gauge number 1 2 3 4 Serial number Calibration certificate ref. Date of calibration

Level of fixed point on load reaction system: before testing ___ after testing ground settlement =

Date &

Time

Load (kN)

Pressure Gauge

Reading

Dial Gauge Readings

Cumulative Settlement

(mm) Remarks

Dial 1 Dial 2 Dial 3 Dial 4 Average


PILE LOAD TEST RECORDS

(Test Result) Load in kN

1000 2000 3000 4000 5000 6000

0

--

5

--

10

--

15

--

Settlement

in

20

--

mm

25

--

30

--

35

--

40

--

Maximum settlement at working load: (Allowable = 20 mm for buildings and 10 mm for all

other structures) Actual = Settlement at maximum test load (S1): (Allowable = S1 less than twice settlement at 90% of

maximum test load (2S2).) Actual S1 = 2S1 = Reported by Verified by Contractor's Representative Project Manager's Representative Date Date (delete as appropriate)

General Materials & Workmanship Specification 1/19 January 2011 Issue No. 5, Volume 1 – Civil & Structural Works Section 18 - Formwork & Finishes to Concrete

SECTION 18 FORMWORK AND FINISHES TO CONCRETE 18.1 GENERAL 18.1.1 General requirements

The works and materials specified herein shall comply with the Sections stated, unless otherwise stated in this Section: (a) surface finish to concrete carriageways shall comply with Section 10; (b) cover spacers for steel reinforcement shall comply with Section 19; and

(c) materials for cement mortar shall comply with Section 20.

18.2 DEFINITIONS AND ABBREVIATIONS 18.2.1 Class

“Class” is a term used to identify the different types and standards of formed, unformed and treated finishes.

18.2.2 Falsework

Falsework is a temporary structure used to support formwork and the permanent structure until the permanent structure is self-supporting.

18.2.3 Formed finish

Formed finish is the finish of the concrete surface produced by the use of formwork. 18.2.4 Formwork

Formwork is the mould against which concrete is cast and which gives the shape and finish to the concrete surface.

18.2.5 Permanent formwork

Permanent formwork is formwork designed to remain in position as part of the Permanent Works.

18.2.6 Profiled formwork, trough moulds and waffle moulds

(a) Profiled formwork is formwork designed to produce a ribbed or patterned finish on the concrete surface.

(b) Trough mould is the mould used with complementary moulds to create an

elongated recess in the underside of a slab. (c) Waffle mould is the mould used with complementary moulds to create square

recesses in a concrete slab.


18.2.7 Sealed plywood

Sealed plywood is plywood which has been sealed with a factory-applied film of phenolic resin or plastic material.

18.2.8 Spatterdash

Spatterdash is a mixture of cement, coarse sand, granite fines and water, used as a rendering on concrete surfaces.

18.2.9 Treated finish

Treated finish is the finish of the concrete surface produced by a treatment applied to a formed or unformed finish.

18.2.10 Unformed finish

Unformed finish is the finish of the concrete surface produced without formwork and by working the concrete surface before the concrete has hardened.

18.3 DESIGN AND PERFORMANCE CRITERIA 18.3.1 Design of falsework and formwork

(a) Falsework and formwork shall be designed, in accordance with the Specification, to maintain the position and shape of the formwork such that the hardened concrete surface complies with the characteristics of finish stated in Table 18.1.

(b) Falsework and formwork shall be capable of being dismantled and removed

without shock, disturbance, damage or loading to the concrete and in such a manner that the specified requirements for removing or leaving in position side formwork, soffit formwork and falsework will be achieved without disturbing other formwork or falsework.

(c) Formwork shall be used to form the top surface of concrete inclined at a slope

exceeding 15° to the horizontal unless it can be demonstrated that the specified finish will be produced without the use of formwork. Formwork to top surfaces shall be anchored to prevent floatation.

18.4 MATERIALS 18.4.1 Formwork

(a) Formwork shall be timber, metal, plastic, fibreglass or other material which will produce the specified finish. Materials used as formers for profiled formwork, chamfers, splays, rebates and other features shall be such that they produce the same finish as the main formwork.

(b) Plywood for formwork shall have a close, uniform grain and the edges shall be

sealed with barrier paint, polyurethane varnish or other impermeable material.


(c) The faces of formwork for Class F3, F4, F5 and F6 finishes shall have a uniform texture and a matt, not a shiny or polished, surface. The edges of the formwork shall be straight and square.

(d) The formwork used for F3, F4 and F5 finished surfaces shall be formed of one

material only. All make up pieces shall be of that material to ensure the same finish is obtained across the whole surface.

(e) All concrete to receive a waterproof membrane shall have a surface finish

either formed or unformed that is compatible with the membrane to be applied.

(f) The surface finish of floor slabs in toilet and kitchen areas where the

waterproofing is to be laid by others shall be unformed finish type U3 unless shown otherwise.

18.4.2 Formwork class of finish

(a) The characteristics of each class of finish shall be as stated in Tables 18.1, 18.2 and 18.3.

(b) Formwork of the type stated in Table 18.1 shall produce a concrete surface

which complies with the characteristics of finish stated in Table 18.1. (c) Unless otherwise shown on the Employer's Drawings, the class of formed and

unformed finish required for different concrete surfaces shall be as stated in Table 18.4. The higher class of finish shall start at least 150 mm below the finished ground level for concrete surfaces which are partly buried.

18.4.3 Release agents

(a) Release agents shall be a proprietary type reviewed without objection by the Project Manager. Release agents containing mineral oils shall not be used. Barrier paint, polyurethane varnish, wax or other materials shall not be used instead of a release agent.

(b) Release agents shall not:

(i) stain or colour the concrete; (ii) affect the bond between the concrete and subsequent coverings; or

(iii) have an adverse effect on any finishes to be applied to the concrete.

(c) Release agents other than those which incorporate a surface retarder to

produce a Class T1 finish shall not affect the hardening of the concrete.

(d) Release agents used on formwork for water retaining structures for potable and fresh water shall be non-toxic and shall not impart a taste to the water.

(e) Release agents used on steel formwork shall contain a rust-inhibiting agent. (f) Release agents used on formwork for Class F4, F5 and F6 finishes shall be a

chemical release agent.


(g) On areas of formwork which are likely to be affected by pedestrian traffic, rain or dust, release agents for Class F4, F5 and F6 finishes shall be a type which evaporates to leave a dry film on the formwork, unless protection from such effects is provided.

Table 18.1 : Formed Finishes

Class of

finish

Type of formwork normally

used

Characteristics of finish

Formwork pattern

Abrupt irregularities

permitted

Gradual irregularities

permitted Specific

requirements

F1 Sawn timber Not required < 10 mm < 15 mm in 2 m No specific requirements

F2 Plywood Pattern of formwork joints and tie holes as

< 5 mm < 10 mm in 2 m Even surface No grout runs

F3 Sealed plywood or fibreglass or steel

stated in Clause 18.6.4 (a) and (b)

< 3 mm < 5 mm in 2 m Even surface No grout runs No grain pattern No fins or other projections

F4 Sealed plywood or fibreglass or steel

< 2 mm < 5 mm in 2 m Uniform, dense and smooth surface No grout runs No grain pattern No crazing No major blemishes No staining or discolouration No fins or other projections Blowholes up to 5 mm dia.

F5 Sealed fibreglass or Steel

< 1 mm < 5 mm in 2 m Uniform, dense and smooth surface No grout runs No grain pattern No crazing No blemishes No staining or discolouration No fins or other projections Blowholes up to 3 mm dia. No holes or embedded metal parts

F6 Sealed plywood

Pattern of formwork stated in Clause 18.6.4.(a)

< 3 mm < 5 mm in 2 m As F4 but no internal ties and/or embedded metal parts allowed


Table 18.2 : Unformed Finishes

Class of

finish

Method of producing

finish

Characteristics of finish Abrupt

irregularities permitted

Gradual irregularities

permitted

Specific requirements

U1 Levelling the surface of the compacted concrete with a screed board

Screed marks < 5 mm

< 10 mm in 2 m No specific requirements

U2 Forming a Class U1 finish and tamping the surface

Tamp marks < 10 mm

Not applicable Ridged surface

U3 Forming a Class U1 finish and wood floating, steel trowelling or power floating the surface

Float marks < 3 mm

< 10 mm in 2 m Uniform, dense and smooth surface

U4 Forming a Class U3 finish and brushing the surface with a stiff brush

Brush marks < 3 mm

< 10 mm in 2 m Rough texture

U5 Forming a Class U3 finish and steel trowelling the surface under firm pressure or power floating the surface

Nil < 5 mm in 2 m Uniform, dense and smooth surface, free from trowel marks No staining or discolouration

Table 18.3 : Treated Finishes

Class of

finish Type of finish

Method of

producing finish Characteristics of finish

T1 Exposed aggregate

Washing and brushing the concrete surface

Cement matrix removed and coarse aggregate exposed to a depth not exceeding one-third of the nominal maximum coarse aggregate size

T2 Point tooled

Point tooling the concrete surface

Cement matrix and aggregate surface removed sufficiently to expose the aggregate with a minimum penetration into the matrix between aggregates T3 Bush

hammered Bush hammering the concrete surface

T4 Broken rib Hammering or chiselling the edges and faces of the concrete surface

Cement matrix and aggregate surface removed Fragments of concrete ribs removed

T5 Light blasting

Blasting the concrete surface by abrasives

Cement matrix removed and coarse aggregate exposed to a minimum depth

T6 Heavy blasting

and compressed air or by water jetting

Cement matrix removed and coarse aggregate exposed to a depth not exceeding one-third of the nominal maximum coarse aggregate size


Table 18.4 : Class of Finish

Description of surface Class of finish Formed Unformed

Surfaces to be covered − screeded − rendered, plastered − tiled − painted

- F2 F2 F4

U2 -

U3 U5

Surfaces for treated finishes F3 U3

Surfaces for pedestrian traffic - U4

Construction joints (for Class T1 finish)

F2 U3

Movement joints F3 U3

Benching, screeds F3 U5

Blinding, foundations, pile caps F1 U1

Piers, blocks, pipe surrounds - below FGL - above FGL

F1 F2

U1 U3

Manholes, chambers - external below FGL

- external above FGL - internal

F1 F2 F2

U1 U3 U3

Culverts, channels - external below FGL


F1 F2 F4

U1 U3 U5

Water retaining structures - external below FGL


F2 F4 F4

U3 U5 U5

Buildings - external below FGL F1 U1 - internal and external surfaces not

exposed to view F2 U3

- exposed to view in plant rooms F3 U3 - exposed to view in non-public

areas F4 U5

- exposed to view in public areas F5 U5

Bridges, retaining walls, walls - below FGL - above FGL, not exposed to direct

public view - above FGL, exposed to direct

public view - internal, not exposed to direct

public view

F1 F4

F5

F2

U1 U5

U5

U1


18.4.4 Formwork ties

(a) Formwork ties shall not be used in any structure which bears against the ground or retains water.

(b) Formwork ties and components shall be a type such that any removable part

can be removed without damaging the concrete; any part left in the concrete shall be at least 40 mm or the specified nominal cover to the reinforcement, whichever is greater, from the concrete surface.

(c) Formwork ties and components used with profiled formwork shall be a type

such that holes left by the ties and components are small enough to be located completely within the recesses in the concrete surface.

18.4.5 Cement mortar for concrete surfaces

(a) All formwork ties and component holes including blowholes shall be filled. (b) Cement mortar for filling blowholes shall consist of cement and fine aggregate

together with the minimum amount of water necessary to achieve a consistency suitable for completely filling the blowholes.

(c) Cement mortar for filling holes left by formwork ties and components shall

consist of 1 part of cement to 3 parts of fine aggregate together with the minimum amount of water necessary to achieve a consistency suitable for compacting the mortar into the holes. The mix shall contain a non-shrink admixture.

(d) Cement mortar for filling blowholes and holes left by formwork ties and

components in concrete surfaces with Class F4, F5 and F6 finishes shall be the same colour as the hardened concrete; light-coloured sand or white cement may be used for this purpose.

18.4.6 Surface retarder

Surface retarders shall be a proprietary type reviewed without objection by the Project Manager and shall not stain or colour the concrete.

18.4.7 Abrasives

Abrasives for blasting shall be grit and shall not contain any silica, iron, clay or other materials which will stain or colour the concrete.


18.5 SUBMISSIONS 18.5.1 Particulars of formwork and finishes to concrete and samples of materials

(a) Particulars and samples of the proposed materials and methods of construction for Class F3, F4, F5, F6, U5 and T finishes shall be submitted to the Project Manager for review without objection as marked 'x' in Table 18.5. The same particulars shall be submitted for other classes of finish if required by the Project Manager. For formwork Class F5 and F6, the extent of each pour shall be proposed by the Contractor and reviewed without objection by the Project Manager so that no visible difference occurs in concrete surfaces in the same general plan.

(b) The particulars and samples submitted for formed, unformed and treated finishes shall include details for trial panels.

(c) Design calculations for formwork and falsework, in accordance with the

requirements of Section 2 of this General Materials and Workmanship Specification, shall be submitted to the Project Manager for review without objection.

Table : 18.5 : Particulars to be Submitted

Particulars to be submitted Formed finishes

Unformed finishes

Treated finishes

Formwork drawings : Panel/trough/waffle construction - Layout and pattern of

panels/troughs/waffles, joints, rebates and formwork ties

X

-

X

: Column construction - Layout and pattern of column

moulds, joints rebates and formwork ties

X

-

X

Design calculations : Check on formwork, falsework, Permanent Works

X

Method statement : Method statement of formwork and falsework erection, including sequence for floor slab and columns

X X X

Samples : Formwork, F3, F4 and F5 Formwork ties Cover spaces

X X X

- - -

- X X

Brand name and manufacturer's literature

: Release agent Curing compound Surface retarder

X X -

- X -

X X X

Programme : Removing formwork Applying treated finishes

X -

- -

- X

Details : Sources of formwork, formwork ties and cover spacers Curing method Filling blowholes Filling formwork tie holes Protecting finishes

X X X X X

- X - - X

X X - X X


18.6 WORKMANSHIP 18.6.1 Trial panels

(a) A trial panel shall be constructed for each Class F4, F5, F6, U5 and T finish to demonstrate that the proposed materials, mix design, methods of production and methods of construction, including curing and removal of formwork, shall produce the specified finish.

(b) Trial panels for Class F4, F5 and F6 finishes shall be constructed before the

relevant formwork for the Permanent Works is erected, and trial panels for Class U5 and T finishes shall be constructed before the relevant Permanent Works is concreted. The trial panels shall be completed at least 4 weeks before the relevant Permanent Works are programmed to commence.

(c) The Contractor shall notify the Project Manager before constructing trial

panels. (d) Trial panels shall be constructed using the materials, mix design, methods of

production and methods of construction, including curing and removal of formwork, submitted to and reviewed without objection by the Project Manager.

(e) Trial panels shall be horizontal, vertical or inclined as appropriate and shall be

constructed at locations reviewed without objection by the Project Manager. Unless otherwise stated in the Contract each trial panel shall be not less than 2 m by 2 m by 300 mm thick, and shall contain reinforcement representative of the most congested reinforcement which will be used in the Permanent Works. Trial panels shall incorporate formwork ties and components, horizontal joints, vertical joints, chamfers, splays, rebates and other features representative of those which will be used in the Permanent Works, including the filling of formwork ties, components and blowholes.

(f) The Contractor shall submit the trial panels to the Project Manager for review

without objection. When the Project Manager has issued a notice of no objection for the trial panels, they shall become a benchmark against which all subsequent finishes of concrete surfaces shall comply. Benchmarks shall be protected from damage and shall be left in position until the Project Manager directs their removal.

18.6.2 Non-compliance: trial panels

If the Project Manager determines that the specified finish has not been produced in the trial panel, particulars of proposed changes to the materials, mix design, methods of production or methods of construction shall be submitted to the Project Manager for review without objection and further trial panels shall be constructed until the specified finish is produced in the trial panel. Further trial mixes shall be made unless the Project Manager directs otherwise.

18.6.3 Commencement of formwork and concreting

Formwork for Class F4, F5 and F6 finishes shall not be erected and elements with Class U5 and T finishes shall not be concreted until the Project Manager has determined that the specified finish has been produced in the trial panel.



The materials, mix design, methods of production or methods of construction, including curing and removal of formwork, used to produce the specified finish in the benchmarks shall not be changed unless reviewed without objection by the Project Manager.

18.6.5 Storage of formwork

(a) Formwork shall be stored off the ground on level supports and in a manner which will not result in damage, deformation or contamination of the formwork.

(b) Formwork for Class F3, F4, F5 and F6 finishes shall be covered and protected

from exposure to conditions which may affect the formwork. 18.6.6 Storage of release agents and surface retarders

Release agents and surface retarders shall be stored in sealed containers marked to identify the contents and protected from exposure to conditions which may affect the material. The materials shall be stored in accordance with the manufacturers' recommendations and shall not be used after the recommended shelf life has been exceeded.

18.6.7 Construction of formwork

(a) Formwork shall not have any splits, cracks or other defects. The faces and edges of formwork shall be clean and formwork faces shall be free of projections.

(b) Formwork which has been previously used shall be repaired and the edges

resealed before it is erected. (c) Formwork shall be firmly supported and individual panels shall be rigid. Joints

between formwork panels, stop ends and adjoining concrete shall be tight and shall not permit grout loss.

(d) Formwork shall be cut in such a manner that reinforcement and built-in

components passing through the formwork are maintained in position; the joints shall be tight and shall not permit grout loss.

(e) Formers for profiled formwork, chamfers, splays, rebates and other features

shall be rigidly and evenly fixed to the formwork along the complete length and shall not permit grout loss.

(f) Formwork ties and components shall be fixed in such a manner that they do

not touch reinforcement or built-in components. Formwork ties and components shall fit tightly against formwork faces and shall not permit grout loss.

(g) If required for compaction, cleaning or inspection, temporary openings shall

be provided in the formwork.


18.6.8 Construction of formwork for Class F2, F3, F4, F5 and F6 finishes

(a) Formwork panels for Class F2, F3, F4, F5 and F6 finishes shall be the same size and shall form a regular pattern as shown on the Employer's Drawings and/or reviewed without objection by the Project Manager. The lines of joints between panels shall be straight and continuous, horizontal and vertical, or inclined to suit the pattern of profiled formwork, and shall be coincident with construction joints and other joints and with recesses in the concrete surface. The number of make-up pieces shall be kept to a minimum and shall be the same material as the formwork system.

(b) Holes left by formwork ties and components in concrete surfaces with

Class F2, F3 and F4 finishes shall be in line horizontally and vertically and shall form a regular pattern reviewed without objection by the Project Manager. Holes in profiled formwork shall be located in such a manner that the holes are completely within recesses in the concrete surface.

(c) Chamfers shall be provided for all external angles of 90° or less in concrete

surfaces with Class F2, F3, F4, F5 and F6 finishes. (d) Formwork for curved concrete surfaces with Class F2, F3, F4, F5 and F6

finishes shall not be made up of a series of flats or straights. 18.6.9 Construction of formwork for Class F3, F4, F5 and F6 finishes

(a) Each type of formwork for either Class F3, F4, F5 and F6 finishes shall be obtained from one source and different types of formwork shall not be mixed. Damaged formwork shall not be used. Parts of steel formwork which will be in contact with concrete shall be free from rust.

(b) For concrete surfaces with Class F3, F4, F5 and F6 finishes, joints between

formwork panels shall be sealed with foamed rubber strips. The foamed rubber strips shall be sufficiently compressible to form a grout-tight joint. The width of the resulting gap between the panels shall not be greater than 1 mm and the sealing strips shall not protrude proud of the surface of the formwork panels. Joints between formwork panels shall not be sealed by tape fixed to the formwork faces.

(c) For concrete surfaces with Class F3, F4, F5 and F6 finishes, joints between

the formwork and its ends, adjoining concrete and built-in components shall be sealed with gaskets of rubber or flexible foamed polyurethane; the gaskets shall be fixed firmly and evenly to the formwork. The joints shall not be sealed by tape fixed to the formwork faces, putty or other sealants.

(d) Formwork for Class F3, F4, F5 and F6 finishes shall be protected from

spillages, rust marks and stains.

(e) For concrete surfaces with Class F3, F4 and F5 finishes, the formed face at all joints between formwork panels and moulds shall be flush.


18.6.10 Built-in components

(a) Built-in components, void formers and box-outs shall be fixed in position before concreting. Void formers and box-outs shall not be used instead of built-in components. Polystyrene shall not be used for void formers and box-outs.

(b) Hardened concrete shall not be cut or broken to provide holes or chases

without being reviewed without objection by the Project Manager. (c) Pipe sleeves, inserts and ducts shall be securely and correctly located within

the specified tolerances. (d) Formwork for openings, chases and holes shall not interfere with the

reinforcement.

(e) Cast-in items shall be temporarily sealed where necessary to ensure that no unintended seepage of grout occurs into channels or recesses of the cast-in item.

18.6.11 Application of release agents

(a) A release agent shall be used on all formwork other than permanent formwork and formwork on which a surface retarder is used to produce a Class T1 finish. The release agent shall be applied by the method and at the rate of application recommended by the manufacturer or as demonstrated to be satisfactory by use in the trial panel.

(b) Formwork faces shall be cleaned before release agents are applied. Concrete, reinforcement and built-in components shall not be contaminated by release agents.

(c) Each type of release agent used on formwork for Class F3, F4, F5 and F6

finishes shall be obtained from one manufacturer and different types of release agent shall not be used on formwork for the same element.

(d) Release agents shall be applied to formwork for Class F3, F4, F5 and F6

finishes after the formwork has been erected and before the reinforcement is fixed or, if this is not practicable, immediately before the formwork is erected. The release agent covering shall be complete and uniform.

18.6.12 Times for removal of falsework and formwork

(a) Falsework and formwork shall not be loosened or removed before the minimum times stated in Table 18.6 have elapsed. The times stated are for a minimum ambient temperature of 15°C, for elements without superimposed loads and for concrete containing OPC, PPFAC or both OPC and PFA.

(b) For the purpose of determining the minimum times for loosening or removing

falsework and formwork, copings at the top of columns in water retaining structures shall be classified as slabs and roof slabs in water retaining structures shall be classified as beams.

(c) For the purpose of Table 18.6, ‘props left in’ shall include a minimum of 4

props over any one span in each orthogonal direction.


(d) Concrete which has a durability exposure of “Very Severe” as indicated on the Employer’s Drawings, shall have the formwork left in place for a minimum period of seven days.

Table 18.6 : Minimum Times for Loosening or Removing Falsework

Type of falsework or formwork Class F1, F2, F3, F4 and F6 finishes Class F5 finish

Concrete without PFA

Concrete with PFA

Concrete with or without PFA

Vertical (non-profiled) (profiled)

12 hours 7 days

15 hours 7 days

48 hours 7 days

Inclined to top surfaces 12 hours 15 hours 48 hours

Soffits of slabs and ribs (props left in) 4 days 4 days 7 days

Soffits of beams (props left in) 7 days 7 days 14 days

Props to slabs and ribs (unloaded) 10 days 10 days 14days

Props to beams (unloaded) 14 days 14 days 14days

Props to cantilevers 28 days 28 days 28 days

18.6.13 Removal of falsework and formwork

(a) Formwork shall be removed without hammering or levering the concrete and in such a manner that there is no shock, disturbance, damage or loading to the concrete or damage to the specified finish. Side formwork shall be removed without disturbing soffit formwork. Soffit formwork shall be removed without disturbing props except where the Contractor has previously submitted a method statement, reviewed without objection by the Project Manager, that demonstrates that the intended prop removal or replacement sequence can be achieved without overstressing the structure, giving due consideration to the strength of the concrete at the time.

(b) Falsework and formwork shall be loosened and removed in a continuous operation and in accordance with a method reviewed without objection by the Project Manager. All formwork shall be loosened before individual panels are removed. Individual panels or make-up pieces shall not be left in position.

(c) Formwork shall be thoroughly cleaned to remove all traces of concrete and

made good to the original standard before any reuse.

(d) Unless formwork has been left in place for curing requirements it must be fully removed immediately after initial loosening so that curing may be carried out.


18.6.14 Unformed finishes

(a) Unformed finishes shall be produced by the methods stated in Table 18.2. (b) Brushing to produce a Class U4 finish shall be carried out in straight lines in a

direction reviewed without objection by the Project Manager. Brushing shall be carried out when the concrete has hardened sufficiently for the float marks to be removed and for the ridges to be formed without displacing the aggregate.

(c) Floating and trowelling shall not be carried out until the concrete has

hardened sufficiently to allow the specified finish to be produced with the minimum amount of floating and trowelling. Excess laitance shall not be produced.

18.6.15 Treated finishes

(a) Treated finishes shall be produced by constructing a concrete surface with a Class F3 or U3 finish as appropriate and applying the treatment to the surface by the methods stated in Table 18.3. Abrupt irregularities in the concrete surface shall be removed before the treatment is applied.

(b) The treatment shall be applied in a continuous operation in accordance with a

programme reviewed without objection by the Project Manager. 18.6.16 Class T1 finish

(a) Washing and brushing to produce a Class T1 finish shall not be carried out until the concrete has hardened sufficiently for the cement matrix to be removed without disturbing the coarse aggregate. After washing and brushing have been completed and the concrete surface has hardened, the surface shall be cleaned.

(b) The cement matrix shall not be removed or the aggregate exposed by

mechanical methods.

(c) Class T1 finishes may be produced by using a surface retarder applied to the formwork or to the concrete surface. The surface retarder shall be applied by the method and at the rate of application recommended by the manufacturer, or as demonstrated to be satisfactory by use on the trial panel.

(d) Plywood to which a surface retarder is to be applied shall be sealed with

barrier paint or polyurethane varnish. The formwork shall be removed in small sections and the coarse aggregate exposed by washing and brushing the concrete surface.

(e) Formwork to which a surface retarder has been applied shall not be re-used

unless a surface retarder is to be used again on the formwork. Formwork to which a surface retarder has been applied and which is to be re-used shall be cleaned before the retarder is reapplied.

18.6.17 Class T2 and T3 finishes

Point tooling to produce Class T2 finishes and bush hammering to produce Class T3 finishes shall be carried out evenly in small areas and not in distinct lines. Tooling and hammering shall not start until at least 7 days after concreting.


18.6.18 Class T4 finish

Hammering or chiseling to produce a Class T4 finish shall be applied from only one direction and only either hammering or chiseling shall be applied, on any one face. Hammering and chiseling shall not start until at least 14 days after concreting.

18.6.19 Class T5 and T6 finishes

(a) Blasting to produce Class T5 and T6 finishes shall not be carried out until the concrete has hardened sufficiently for the cement matrix to be removed without disturbing the coarse aggregate. Adjacent surfaces shall be protected from blasting and dust shall be controlled by screens and by water-spraying.

18.6.20 Remedial and repair work on concrete surfaces

(a) Remedial or repair work shall not be carried out on concrete surfaces unless reviewed without objection by the Project Manager.

(b) Prior to any mechanical work being carried out to any concrete surface, a trial

repair panel shall be offered to the Project Manager for review without objection.

(c) Abrupt irregularities shall be removed from concrete surfaces which will be

painted or to which tiles will be fixed with adhesives. (d) For slipformed surfaces, as the concrete emerges from the shutter, any drag

cracks shall immediately be closed by means of a wooden float. The surface of the concrete shall then be gently brushed horizontally to produce a light uniform texture. Any necessary cutting out of concrete shall be carried out immediately and made good as soon as possible thereafter using concrete taken from the slipforming mix with the coarse aggregate sieved out as necessary.

18.6.21 Filling blowholes and formwork tie holes

(a) Blowholes exceeding 3 mm in size in water retaining structures and watertight structures, and blowholes exceeding 10 mm in size in other structures shall be filled with cement mortar. The size of blowholes shall be the maximum dimension measured across the hole on the concrete surface. If the number and size of blowholes in concrete surfaces with Class F3 and F4 finishes is greater than in the trial panel the blowholes shall be filled.

(b) Holes left by formwork ties and components shall be cleaned and filled by

ramming cement mortar into the holes in layers. Holes in concrete surfaces with a Class F4 finish shall be filled to a level slightly below the concrete surface; the holes shall not be overfilled and rubbed down.

(c) Filling of blowholes and holes left by formwork ties and components shall be

carried out as soon as practicable after the Project Manager has inspected the finish and with the minimum interruption to curing. Filling of blow holes in Class F5 finish shall not be permitted.


18.6.22 Spatterdash and bonding agents

(a) Spatterdash shall consist of cement and coarse sand or granite fines in the proportions 1:2 by volume mixed with the minimum amount of water necessary to achieve the consistency of a thick slurry. Spatterdash shall be thrown with a hand trowel onto the surface to a thickness not exceeding 6 mm and shall cover at least 60% of the area which is to be plastered or rendered. Spatterdash shall be wetted one hour after application and shall be allowed to cure and harden before under coats are applied.

(b) Spatterdash shall be applied as soon as practicable after the Project Manager

has inspected the finish and after the concrete surface has been cleaned and wetted.

(c) Bonding agents for attaching finishes to concrete surfaces shall be a

proprietary type reviewed without objection by the Project Manager and shall be applied by the method and at the rate recommended by the manufacturer.

18.6.23 Construction Tolerances

(a) Except where otherwise specified in the Contract, deviation of concrete surfaces from the specified lines, grades and dimensions shown on the Employer's Drawings shall comply with the tolerances set-out in this sub-section. The dimensions shown on the Employer’s Drawings show the required as-constructed position after deflections due to self weight and superimposed dead loads.

(b) Final measurements to confirm that the Works are within the specified

tolerances shall be made at 28 days after casting for in-situ construction. (c) The specified tolerances shall not be cumulative.


(d) The permitted deviations for in-situ concrete construction shall be as follows :

(i) Variation in equivalent positions, in plan, of a concrete surface of a column or wall, between two successive pours at floor level

+5 mm in any direction

(ii) Variation from the vertical: - In the lines and surfaces of concrete

columns and walls - In the lines and surfaces of conspicuous

items such as corners of columns, architectural rebates, etc.

No more than 1:300, up to 15 mm maximum measured horizontally from true vertical No more than 1:500, up to 10 mm maximum, measured horizontally from true vertical

(iii) Variation in normal level of floor slab, as shown on the drawings

± 5 mm

(iv) Variation from the horizontal (Refer Table 18.2 for unformed surfaces other than slab surfaces)

No more than 1:500, up to +10 mm, -5 mm maximum for upper slab surfaces No more than shown in Table 18.1, up to -10 mm, +0 mm maximum for slab and rib soffits, measured vertically from true level

(v) Variation from true plan position and from correct lines

No more than 1:300, up to 15 mm maximum measured horizontally from true plan position

(vi) Variation in cross section and linear dimensions

Members up to 1500 mm dimension; +5 mm, -0 mm Members over 1500 mm; +10 mm, -0 mm

(vii) Openings, sleeves and embedded fixtures:

- Variation of location 6 mm

- Variation of size ± 3 mm (viii) Variation in steps:

- In a flight, maximum accumulative tolerance,

rise ± 3 mm tread ± 6 mm

- In consecutive steps, rise ± 2 mm tread ± 3 mm


(e) The permitted deviation for in-situ concrete items associated with mechanical and electrical plant shall be as follows:

(i) Variation from verticality:

- Plinths and machine bases

± 3 mm in 8 m (± 3 mm max)

- Cable and pipe trenches ± 6 mm per 8 m (± 6 mm max)

(ii) Variation from level or specific gradient or batter:

- Plinths and machine bases ± 3 mm in 8 m (± 3 mm max)

- Cable and pipe trenches ± 6 mm per 8 m (± 6 mm max)

(iii) Variation from specified centre lines or setting out lines:

- Plinths and machine bases ± 3 mm

- Cable and pipe trenches ± 6 mm

(iv) Variation from specified cross-sectional dimensions:

- Plinths and machine bases ± 3 mm

- Cable and pipe trenches ± 6 mm

- Variation from specified position for bolt

boxes

6 mm

- Variation from specified position for foundation bolts

6 mm

(v) The plan distance between ends and sides of escalator and moving walkway

voids and pits shall be within +10mm/-0mm.

(f) Notwithstanding the maximum tolerances specified in the preceding sub-sections, there shall be no misalignment at vertical or horizontal joints on exposed faces. Also, any exposed concrete face which shows an undulating or irregular surface, even though it may be within the stated tolerances, will not be accepted.

(g) Note that where a tolerance is related to a given length, the tolerance for any lesser length shall be in linear proportion thereto, subject to review without objection by the Project Manager. For verticality, the tolerance for each lift of concrete shall be calculated on the same basis with a normal maximum of 3 mm deviation from true vertical.

(h) The Contractor shall determine the amount of pre-set deflection and/or pre-

camber that may be necessary in formwork to ensure that the as constructed position of the concrete is within the specified tolerances.


18.6.24 Temporary fixings left in

Temporary fixings left in the completed concrete structure shall be left with a minimum of 40mm cover and filled over with a polymer modified mortar, reviewed without objection by the Project Manager. Temporary fixings shall not be left in on concrete surfaces that are exposed to public view or in water retaining structures.

18.7 INSPECTION, TESTING & COMMISSIONING 18.7.1 Inspection of formwork and reinforcement

(a) The Contractor shall allow sufficient time for the Project Manager to inspect the completed formwork and reinforcement, including trial panels, before carrying out any work, including fixing reinforcement adjacent to formwork and erecting formwork adjacent to reinforcement, which will make access to the formwork faces or reinforcement difficult.

(b) The Contractor shall allow sufficient time for the Project Manager to inspect

formwork for Class F3, F4, F5 and F6 finishes before it is erected and shall notify the Project Manager before erecting the formwork.

18.7.2 Inspection of finishes

(a) Before any subsequent work is carried out on a concrete surface, the surface will be inspected by the Project Manager to determine if the specified finish has been produced. Formed finishes shall be inspected as soon as the formwork has been removed.

(b) Blowholes or holes left by formwork ties and components shall not be filled

and spatterdash or other coverings shall not be applied before the inspection. 18.7.3 Compliance of finishes

(a) Concrete surfaces shall have the characteristics stated in Tables 18.1 and 18.2 for the different classes of formed and unformed finish before any subsequent work is carried out on the concrete surface and shall have the characteristics stated in Table 18.3 for the different classes of treated finish.

(b) The Project Manager will determine if the specified finish has been produced

and will use the trial panels as a benchmark. (c) Abrupt irregularities shall be measured by direct measurement. Gradual

irregularities shall be measured using a 2 m long straight edge on surfaces intended to be flat and by a method reviewed without objection by the Project Manager on other surfaces.

(d) All exposed in-situ and pre-cast concrete surfaces shall match for colour and

surface texture.

Materials & Workmanship Specification 1/14 January 2011 Issue No. 5, Volume 1 – Civil & Structural Works Section 19 – Steel Reinforcement

SECTION 19 STEEL REINFORCEMENT

19.1 DEFINITIONS AND ABBREVIATIONS 19.1.1 Reinforcement Connector

“Reinforcement connector” is a coupler or sleeve designed to transmit the force between two bars in tension or compression.

19.1.2 Bar Reinforcement

“Bar reinforcement” is hot rolled steel bar or cold worked steel bar or cold reduced wire reinforcement.

19.1.3 Fabric Reinforcement

Fabric reinforcement is a mesh or grid of bar reinforcement welded in the factory in accordance with BS 4483.

19.1.4 Batch: Reinforcement

A batch of bar reinforcement, fabric reinforcement or reinforcement connectors for tension joints is any quantity of bar reinforcement, fabric reinforcement or reinforcement connectors for tension joints of the same type, size and grade, manufactured by the same mill, covered by the same mill and testing certificates and delivered to Site at any one time. In addition, for epoxy coated reinforcement and galvanized reinforcement, the coatings shall have been applied at the same coating factory and shall be covered by the same testing certificates.

19.2 MATERIALS 19.2.1 Bar Reinforcement and Fabric Reinforcement

(a) Except where noted on the Employer's Drawings, bar reinforcement and fabric reinforcement shall comply with the following:

Hot rolled steel bars : Construction Standard CS2

Cold worked steel bars : BS 4461 Steel fabric : BS 4483 Cold reduced steel wire : BS 4482 Deformed high yield steel bars : BS 4449, Type 2 bond classification

(b) All reinforcement shall comply with the requirements of Practice Note for Authorised Persons and Registered Structural Engineers (PNAP) 122 issued by the Buildings Department.


19.2.2 Epoxy Coatings to Reinforcement

(a) Epoxy coatings to reinforcement and patching material for epoxy coatings shall comply with ASTM A775M except as stated in Sections 19.2.2 (b), 19.4.5, 19.5.3, 19.5.4 and 19.5.8. The coatings shall be applied by the electrostatic spray method in accordance with ASTM A775M at a factory reviewed without objection by the Project Manager.

(b) The film thickness of the coating after curing shall be at least 0.15 mm and

shall not exceed 0.25 mm over the complete periphery including deformations and ribs. The bond classification of coated bars determined in bond performance tests shall not be less than that of uncoated bars.

19.2.3 Galvanizing to Reinforcement

(a) Galvanizing to reinforcement shall comply with BS 729. Galvanized reinforcement shall be chromate passivated as part of the galvanizing process by quenching the bars immediately after galvanizing in a solution containing at least 0.2% sodium dichromate in water. The galvanizing shall be applied after cutting and bending of the reinforcement.

(b) Metallic zinc-rich priming paint for repairs to galvanized reinforcement shall

comply with BS 4652. 19.2.4 Reinforcement Connectors

(a) Reinforcement couplers shall be of proprietary type, accepted by the Buildings Department and reviewed without objection by the Project Manager.

(b) Reinforcement connectors for tension joints shall be a cold swaged or threaded type. The connectors shall develop the full tensile strength of the parent bar and shall comprise high tensile steel studs and seamless steel tubes fitted with protective plastic caps.

(c) Reinforcement connectors for compression joints shall be wedge locking or

bolted sleeve type. (d) The concrete cover to reinforcement connectors shall not be less than the

specified minimum.

(e) Reinforcement connectors shall not be used with galvanized or epoxy coated reinforcement.

19.2.5 Cover Spacers

(a) Cover spacers for reinforcement shall be concrete blocks or a proprietary plastic or concrete type. Proprietary cover spacers shall be reviewed without objection by the Project Manager.

(b) Cover spacers for Class F3, F4, F5 and F6 finishes shall be a proprietary

plastic or concrete type. Cover spacers for epoxy coated reinforcement and galvanized reinforcement shall be a proprietary plastic type.


(c) Cover spacers shall be as small as practicable consistent with their purpose and shall be designed to maintain the specified cover to reinforcement. Cover spacers shall be capable of supporting the weight of reinforcement and construction loads without breaking, deforming or overturning.

(d) The strength and durability of concrete blocks and proprietary concrete cover

spacers shall not be less than that of the surrounding concrete. (e) Cover spacers for Class F3, F4, F5 and F6 finishes shall be of a colour similar

to that of the surrounding concrete and shall not cause indentations in the formwork.

(f) The use of Site manufactured concrete spacer blocks will only be permitted if the Project Manager has reviewed without objection the method of manufacture and quality of the block.

19.2.6 Chairs, Supports and Spacers

Chairs, supports and spacers other than cover spacers for reinforcement shall be steel. The steel shall be coated with nylon, epoxy, plastic or other dielectric material for epoxy coated reinforcement and shall be galvanized for galvanized reinforcement.

19.2.7 Tying Wire

Tying wire for reinforcement adjacent to and above Class F4, F5 and F6 finishes shall be 1.2 mm diameter stainless steel wire. Tying wire for epoxy coated reinforcement shall be 1.6 mm diameter soft annealed steel wire coated with nylon, epoxy, plastic or other dielectric material. Tying wire for galvanized reinforcement shall be 1.6 mm diameter galvanized soft annealed steel wire. Tying wire for other reinforcement shall be 1.6 mm diameter soft annealed steel wire.

19.2.8 Tying Devices and Clips

Tying devices and clips for reinforcement shall be a proprietary steel type reviewed without objection by the Project Manager. Tying devices and clips for reinforcement adjacent to and above Class F4, F5 and F6 finishes shall be stainless steel. Tying devices and clips for epoxy coated reinforcement shall be coated with nylon, epoxy, plastic or other dielectric material. Tying devices and clips for galvanized reinforcement shall be galvanized.

19.3 SUBMISSIONS 19.3.1 Particulars of Bar Reinforcement and Fabric Reinforcement

The following particulars of the proposed bar reinforcement and fabric reinforcement shall be submitted to the Project Manager for review: (a) for Class 1 bar reinforcement, a mill certificate from the quality assured

stocklist in accordance with CS2 Cl.4.1.3 and a copy of the manufacturer's third party certificate;

(b) for Class 2 bar reinforcement, a mill certificate from the quality assured

stocklist in accordance with CS2 Cl.4.1.4 and a copy of the manufacturer’s third party certificate;


(c) for Class 3 bar reinforcement, a mill certificate from the supplier in accordance with CS2 Cl.4.2;

(d) Upon delivery of bar reinforcement the Contractor shall submit a test report

containing the details specified in CS2, Cl.3.3.3 and Cl.3.3.5; and (e) for fabric reinforcement, a certificate form the manufacturer showing the

manufacturer's name, the date and place of manufacture and showing that the reinforcement complies with the requirements stated in the Contract including details of: (i) bond classification of deformed bar reinforcement and of fabric

reinforcement; (ii) cast analysis; (iii) carbon equivalent value; (iv) results of tensile, bend and rebend tests, including the effective

cross-sectional area for tensile tests;

(v) results of bond performance tests for deformed bar reinforcement and for fabric reinforcement; and

(vi) results of weld tests for fabric reinforcement.

19.3.2 Particulars of Epoxy Coatings to Reinforcement

The following particulars of the proposed epoxy coatings to reinforcement shall be submitted to the Project Manager for review without objection:

(a) name and location of the coating factory; (b) coating material and method of application; and (c) a certificate from the manufacturer showing the date and place of application

of the coating and showing that the epoxy coatings comply with the requirements stated in the Contract and including results of tests for:

(i) thickness of coating; (ii) chemical resistance;

(iii) resistance to applied voltage;

(iv) chloride permeability;

(v) adhesion of coating;

(vi) bond strength to concrete;

(vii) abrasion resistance;

(viii) impact strength; and (ix) hardness.


19.3.3 Particulars of Galvanized Coatings to Reinforcement

The following particulars of the proposed galvanized coatings to reinforcement shall be submitted to the Project Manager for review:

(a) name and location of the coating factory; and (b) a certificate from the manufacturer showing the date and place of application

of the coating and showing that the galvanized coatings comply with the requirements stated in the Contract and including results of tests for: (i) weight of coating; and (ii) uniformity of coating.

19.3.4 Particulars of Reinforcement Connectors

Particulars of the proposed materials and methods of installation for reinforcement connectors, including the manufacturer's literature, and tensile test results, shall be submitted to the Project Manager for review without objection.

19.3.5 Particulars Suitable for Submission to Buildings Department

All submissions under Clauses 19.3.1 – 19.3.4 shall be in a form suitable for submission to the Buildings Department.

19.3.6 Bending Schedules

(a) Unless otherwise stated in the Contract, for works designed in detail by the Employer, any bending schedules by the Employer are provided for the information of the Contractor but are not guaranteed correct. The Contractor shall check the schedules and submit to the Project Manager for review without objection, any amendments, additions or deductions as may be necessary to conform to the Employer's Drawings and the Specification at least 28 days before bending of the reinforcement commences.

(b) Should any alterations to the bending schedules be required by the Contractor

to facilitate his sequence of construction, location of construction joints, box-outs, openings and the like, then the revised bending schedules together with explanatory notes and diagrams shall be submitted to the Project Manager for review without objection at least 28 days before bending of the reinforcement commences.

19.3.7 Representative Samples of Materials

Representative samples of the following proposed materials shall be submitted to the Project Manager at the same time as particulars of the material are submitted:

(a) bar and fabric reinforcement; (b) epoxy coated bar and fabric reinforcement; (c) galvanized bar and fabric reinforcement; (d) reinforcement connectors for tension joints and compression joints;


(e) cover spacers; and (f) tying wire, tying devices and clips.

19.4 WORKMANSHIP 19.4.1 Handling of Reinforcement

(a) Reinforcement shall not be subjected to rough handling, shock loading or dropping from a height.

(b) Nylon, rope or padded slings shall be used for lifting epoxy coated

reinforcement and galvanized reinforcement; bundles shall be lifted with a strongback or with multiple supports to prevent abrasion.

19.4.2 Storage of Reinforcement

(a) Reinforcement shall be stored off the ground on level supports and in a manner which will not result in damage or deformation to, or in contamination of, the reinforcement. Fabric reinforcement shall be stored horizontally. Where conditions of saline water exist the Contractor shall provide hard standing reviewed without objection by the Project Manager for steel storage and bending and shall prevent contact between steel and saline water.

(b) Different types and sizes of reinforcement shall be stored separately. (c) Reinforcement shall not be stored on or adjacent to concrete surfaces which

form part of the Permanent Works or existing structures. (d) Epoxy coated reinforcement and galvanized reinforcement shall be stored on

wooden or padded cribbing. 19.4.3 Cutting and Bending Reinforcement

(a) Reinforcement shall be cut and bent in accordance with BS 4466 to the specified shapes and dimensions and shall be bent at temperatures of at least 5°C and not exceeding 100°C.

(b) Epoxy coated reinforcement shall be bent cold. Bar cutting and bar bending

equipment for epoxy coated reinforcement shall have padded supports and contact areas shall be fitted with nylon or plastic mandrels.

(c) Grade 460 reinforcement shall not be rebent or straightened after bending,

with the exception of reinforcement of 20mm diameter (or less) which projects from hardened concrete or is out of position. Such reinforcement and Grade 250 reinforcement which projects from hardened concrete may be bent aside and rebent provided that the internal radius of the bend is at least three times the diameter of the bar for Grade 460 and twice the diameter of the bar for Grade 250, and that bending is not carried out by levering against the concrete or by other methods which will damage the concrete.

(d) The ends of bars to be used with reinforcement connectors for compression

joints shall be sawn square with all burrs removed.


19.4.4 Surface Condition of Reinforcement

(a) Reinforcement shall be clean at the time of fixing and shall be free from loose mill scale, loose rust or any substance which is likely to reduce the bond or affect the reinforcement or concrete chemically. Reinforcement shall be maintained in this condition until concrete is placed around it.

(b) If the surface condition of the reinforcement deteriorates such that it does not

comply with the requirements stated in Section 19.4.4(a), the reinforcement shall be cleaned or dealt with by other methods reviewed without objection by the Project Manager, prior to being used.

19.4.5 Repairs to Epoxy Coatings and Galvanized Coatings

(a) If the coating to epoxy coated reinforcement is delaminated or split at any point or if the coating to epoxy coated reinforcement or galvanized reinforcement is damaged:

(i) at any point by an amount exceeding 25 mm² in area or 50 mm in

length;

(ii) at more than three points in a 1 m length by amounts each not exceeding 25 mm² in area or 50 mm in length; or

(iii) at more than six points in the cut and bent length of a bar by amounts

each not exceeding 25 mm² in area or 50 mm in length,

then that part of the reinforcement shall not be used in the Permanent Works. (b) Damaged areas not exceeding 25 mm² in area or 50 mm in length and cut

ends of epoxy coated reinforcement, other than that rejected under Section 19.4.5(a) shall be repaired using patching material applied in accordance with the manufacturer's recommendations.

(c) Damaged areas not exceeding 25 mm² in area or 50 mm in length and cut

ends of galvanized reinforcement shall be repaired by applying two coats of metallic zinc-rich priming paint. Sufficient paint shall be applied to provide a zinc coating of at least the same thickness as the galvanized coating.

(d) Repairs to epoxy coatings and galvanized coatings shall be carried out within

8 hours of cutting or damage. Traces of rust shall be removed from the surface of the reinforcement before the repair is carried out.

19.4.6 Fixing Reinforcement

(a) Bar reinforcement, fabric reinforcement and reinforcement connectors for tension joints from each batch shall not be fixed until testing of the batch has been completed.

(b) Reinforcement shall be fixed rigidly in position and secured against

displacement. (c) A sufficient number of intersecting and lapping bars shall be tied using tying

wire, tying devices or clips to prevent movement of the reinforcement. The ends of tying wire, tying devices and clips shall not encroach into the cover to reinforcement.


(d) Laps and joints in reinforcement shall be made only at the positions specified on the Employer's Drawings and by the specified methods except where otherwise reviewed without objection by the Project Manager in accordance with Section 19.3.5(b).

(e) Sufficient numbers of cover spacers, chairs, supports and spacers other than

cover spacers shall be provided to maintain the reinforcement in the correct location and to maintain the specified cover at all positions. Cover spacers, chairs, supports and spacers other than cover spacers shall be placed at a maximum spacing of 1.5 m. Chairs, supports and spacers other than cover spacers shall be positioned adjacent to or above cover spacers and shall have at least the same cover as that specified for the reinforcement.

(f) Prefabricated reinforcement cages shall be rigidly supported and braced

before moving. (g) Reinforcement which is free-standing shall be secured in position and braced

to prevent movement due to wind and other loads. 19.4.7 Fixing Reinforcement Connectors

Reinforcement connectors shall be fixed in accordance with the manufacturer's recommendations and using equipment recommended by the manufacturer.

19.4.8 Welding of Reinforcement

Reinforcement shall not be welded. 19.4.9 Exposed Reinforcement

Reinforcement which is to be left exposed shall be protected by coating with cement slurry. The bars shall be cleaned and recoated by the same method if the original coating has begun to deteriorate.

19.4.10 Access Over Reinforcement

Reinforcement shall not be contaminated or displaced as a result of access over the reinforcement; access shall be obtained by using planks and ladders.

19.4.11 Tolerances: Reinforcement

(a) Tolerances on cutting and bending reinforcement shall comply with BS 4466, Table 1, 2 and 4.

(b) Unless otherwise stated on the Employer's Drawings, reinforcement shall not

be out of the designed position by more than 5 mm and shall not encroach into the minimum specified cover.

(c) Reinforcement bars may be moved as necessary to avoid interference with

other reinforcing steel or embedded items. If bars are moved more than one bar diameter or enough to exceed the above tolerance, the resulting arrangement of bars shall be subject to review without objection by the Project Manager.


19.5 INSPECTION TESTING AND COMMISSIONING 19.5.1 Inspection of Reinforcement

The Contractor shall allow sufficient time for the Project Manager to inspect the completed reinforcement before carrying out any work, including erecting formwork adjacent to reinforcement, which will make access to the reinforcement difficult. The Contractor shall notify the Project Manager before carrying out such work.

19.5.2 Samples: Reinforcement

(a) Samples of bar reinforcement, fabric reinforcement and reinforcement connectors for tension joints from each batch of the material delivered to Site, at least 14 days before fixing of the reinforcement starts, shall be submitted to the Project Manager for review without objection. The number of samples to be provided from each batch shall be as stated in Table 19.1.

(b) The number of specimens in each sample shall be as follows:

(i) bar reinforcement (without epoxy coating or in accordance with CS2

galvanized coating) Table 9

(ii) epoxy coated bar reinforcement and 2 additional specimens to galvanized bar reinforcement those specified in CS2

Table 9 for bar reinforcement

(iii) fabric reinforcement (without epoxy coating 3

or galvanized coating)

(iv) epoxy coated fabric reinforcement and 4 galvanized fabric reinforcement

(v) reinforcement connectors for tension joints 3 (c) The list of bars currently acceptable for abbreviated testing are given in

Construction Standard CS2. (d) Each specimen of bar reinforcement shall be 1 m long. Each specimen of

fabric reinforcement shall be 1.2 m long by 1.2 m wide and shall contain at least three wires in each direction. Each specimen of reinforcement connectors shall consist of one reinforcement connector joined to two lengths of bar each 500 mm long; the bars shall be the same type, size, grade and source of manufacture as the bars to which the reinforcement connector will be fixed in the Permanent Works. The assembly shall be prepared in the same manner as that to be used for the Permanent Works.

(e) Each specimen of bar reinforcement and fabric reinforcement shall be taken

from different bars or sheets in the batch. The ends of specimens shall be cut square and loose mill scale and rust shall be removed by wire brushing before delivery to the laboratory.


(f) For epoxy coated bar reinforcement, two additional specimens shall be selected from each batch of reinforcement, as directed by the Project Manager, for epoxy coating tests on thickness, adhesion and continuity in addition to the requirements of tensile tests, bend tests and rebend tests. Each specimen shall be a 2 m length piece cut at least 1m from the ends of a 12 m length bar. Specimens shall be selected from different bundles of the reinforcement batch.

Table 19.1 : Rate of Sampling of Reinforcement and Reinforcement

Connectors for Tension Joints

Description Size of Batch No. of samples

per batch

Bar reinforcement In accordance with

Table 9 of CS2

Fabric reinforcement 0 – 50 tonnes 1

exceeding 50 tonnes 1 for each 50 tonnes or part thereof

Reinforcement connectors

for tension joints

less than 100 No. 1

100 – 500 No. 2

exceeding 500 No. 3

19.5.3 Testing: Reinforcement

(a) Testing of reinforcement shall be in accordance with Practice Note for Authorized Persons and Registered Structural Engineers No. 122. All verification tests shall be carried out by testing laboratories accredited by HOKLAS

(b) Each sample of bar reinforcement and fabric reinforcement shall be tested to

determine the yield stress, elongation, tensile strength, bending and rebending properties and unit mass. Each sample of fabric reinforcement shall also be tested to determine the weld shear strength. Each sample of epoxy coated reinforcement shall also be tested to determine the thickness, adhesion and continuity of the coating. Each sample of galvanized reinforcement shall also be tested to determine the weight and uniformity of coating.

(c) Each sample of reinforcement connectors for tension joints shall be tested to

determine the tensile strength and the slip between the reinforcement connector and the parent bars.

(d) The number of tests on each sample shall be as stated in Table 19.2.


(e) The method of testing shall be in accordance with the following:

Hot rolled steel bars : Construction Standard CS2; Cold worked steel bars : BS 4461; Cold reduced steel wire : BS 4482; Steel fabric : BS 4483; and Galvanized coating : BS 729.

(f) The method of testing epoxy coatings shall be in accordance with ASTM A775

except that the test for adhesion of coating shall be carried out on 180° bends to design radii in accordance with BS 4466, Table 1. Bends shall be performed at a uniform rate and shall be capable of being completed within 15 seconds without visual distress to the coating.

(g) Tests shall be carried out on specimens having a temperature of between 5°C

and 30°C. 19.5.4 Compliance Criteria: Epoxy Coatings to Reinforcement

The results of tests for thickness, adhesion and continuity of epoxy coatings to reinforcement shall comply with the following requirements: (a) at least 90% of measurements taken to determine the thickness of the coating

shall be within the specified limits. The thickness of the coating shall be at least 0.10 mm and shall not exceed 0.30 mm at any point, other than at repaired areas of coating;

(b) cracking or debonding of the coating shall not be visible to the unaided eye on

any part of the bent bar; and (c) the continuity of the coating shall comply with ASTM A775, Clause 7.2.


Table 19.2 : Number of Tests on Each Sample of Reinforcement

Description

Type and number of tests

Yield, Elongation and Tensile

Bend Rebend Unit Mass

Weld Shear Stress

Thickness, Adhesion

and Continuity

Weight and Uniformity

of Galvanized

Coating

Pitch, Dimension

Bar reinforcement

No. of tensile, bend and rebend tests in accordance with CS2 Table 9 and one unit mass test accompanied with each tensile test.

- - - - - - - -

Cold reduced steel wire

3 - 1 3 - - - -

Steel fabric - fabric sheet - - - 3 1 - - - - longitudinal wire 3 - 1 - - - - 1 - transverse wire 3 - 1 - - - - 1 Epoxy coating - - - - - 2 - - Galvanized coating

- - - - - 2 -

Reinforcement connectors for tension joints

3 - - - - - - -

19.5.5 Non-compliance: Characteristic Strength

(a) A batch of bar reinforcement or fabric reinforcement shall be considered as not complying with the specified requirements for characteristic strength if the yield stress in any tensile test carried out on any sample taken from the batch is less than 93% of the specified characteristic strength.

(b) If the yield stress in any tensile test is less than the specified characteristic

strength but equal to or greater than 93% of the specified characteristic strength, additional samples shall be provided from the same batch and additional tests for yield stress shall be carried out. The number of samples shall be as stated in Clause 5.1.4 of the Construction Standard CS2. The batch shall be deemed to comply with the Specification if the test specimens meet the requirements of Clause 5.1.2 of the Construction Standard CS2.

(c) The number of specimens in each additional sample shall be seven. (d) The number of tests on each additional sample of bar reinforcement shall be

seven. The number of tests on the longitudinal wires and on the transverse wires of each additional sample of fabric reinforcement shall be seven.

(e) The batch shall be considered as not complying with the specified

requirements for characteristic strength if the yield stress in any additional test is less than 93% of the specified characteristic strength.


19.5.6 Non-compliance: Elongation, Tensile Strength, Bending, Rebending, Unit Mass, Weld Shear Strength If any test specimen fails to meet the tensile strength, elongation, bend or rebend test requirements as stipulated in Construction Standard CS2, two additional test specimens may be taken from different bars of the same batch and be subjected to the test or tests which the original specimen failed. If both additional test specimens pass the retests the batch from which they were taken shall be deemed to comply with this Specification. If either of them fails, the batch shall be deemed not to comply with this Specification.

19.5.7 Non-compliance: Thickness, Adhesion and Continuity of Epoxy Coatings

(a) If the result of any test for thickness, adhesion or continuity of epoxy coatings to reinforcement does not comply with the specified requirements for the property, additional samples shall be provided from the same batch and additional tests for the property shall be carried out. The number of additional samples shall be as stated in Table 19.1.

(b) The number of specimens in each additional sample shall be as follows:

(i) epoxy coated bar reinforcement 4 (ii) epoxy coated fabric reinforcement 2

(c) The number of tests on each additional sample shall be four.



19.5.8 Non-compliance: Weight and Uniformity of Galvanized Coatings

(a) If the result of any test for weight or uniformity of galvanized coatings to reinforcement does not comply with the specified requirements for the property, additional samples shall be provided from the same batch and additional tests for the property shall be carried out. The number of additional samples shall be as stated in Table 19.1.

(b) The number of specimens in each additional sample shall be as follows:

(i) galvanized bar reinforcement 4 (ii) galvanized fabric reinforcement 2

(c) The number of tests on each additional sample shall be four.




19.5.9 Compliance Criteria: Reinforcement Connectors for Tension Joints

The results of tensile tests on specimens of reinforcement connectors for tension joints shall comply with the following requirements:

(a) the tensile strength shall not be less than the specified requirements for the

parent bar; and (b) the slip between the reinforcement connector and the parent bars shall not

exceed 0.2 mm in 2 minutes at the specified characteristic strength. 19.5.10 Non-compliance: Slip of Reinforcement Connectors

(a) If the result of any test for slip of reinforcement connectors for tension joints

does not comply with the specified requirements for slip, additional samples shall be provided from the same batch and additional tests for slip shall be carried out. The number of additional samples shall be as stated in Table 19.1.

(b) The number of specimens in each additional sample shall be six. (c) The number of tests on each additional sample shall be six. (d) The batch shall be considered as not complying with the specified

requirements for slip if the result of any additional test does not comply with the specified requirements for slip.

Materials & Workmanship Specification 1/53 January 2011 Issue No. 5, Volume 1 – Civil & Structural Works Section 20 – Concrete & Joints in Concrete

SECTION 20 CONCRETE AND JOINTS IN CONCRETE

20.1 GENERAL 20.1.1 Sprayed Concrete

Sprayed concrete shall comply with Section 8 except as stated in this section. 20.1.2 Joints in Concrete Carriageways

Joints in concrete carriageways shall comply with Section 10. 20.1.3 Movement Joints

(a) Movement joints shall be positioned as shown on the Employer's Drawings and shall comply with this section.

(b) Movement joint bearings shall be designed by the Contractor.

20.1.4 Prestressed Concrete Prestressed concrete shall comply with Section 21.

20.2 DEFINITIONS & ABBREVIATIONS 20.2.1 Cementitious Content

“Cementitious content” or “cement content” is the mass of cement per cubic metre of compacted concrete or, if cement and PFA are used as separate constituents, the combined mass of cement and PFA per cubic metre of compacted concrete.

20.2.2 Grade

“Grade” is a term used to identify the different concrete mixes in terms of grade strength or in terms of grade strength and nominal maximum aggregate size.

20.2.3 Grade Strength

Grade strength is the compressive strength of concrete stated in the Contract. For designed mix concrete, compliance with the grade strength shall be ascertained in accordance with Clause 20.8.14.

20.2.4 Designation of Concrete Mixes

(a) Designed mix concrete shall be designated by the grade strength in MPa followed by the nominal maximum aggregate size in mm and the suffix D.

(b) Standard mix concrete shall be designated by the grade strength in MPa

followed by the nominal maximum aggregate size in mm and the suffix S.


(c) Designed mix concrete or standard mix concrete of the same grade strength but with different constituents, workabilities or other properties shall be designated as such by the addition of a suitable description. If the Grade of concrete is designated by one number only, the number shall be the grade strength in MPa.

(d) Prescribed mix concrete shall be designated by the grade strength in MPa

followed by the nominal maximum aggregate size in mm and the suffix P. 20.3 RELEVANT CODES AND STANDARDS 20.3.1 Cement

(a) Cement shall comply with the following:

(i) Ordinary and rapid hardening Portland cement : BS 12:1996 (ii) Sulphate resisting Portland cement : BS 4027 (iii) Portland pulverised-fuel ash cement : BS 6588.

20.3.2 PFA PFA shall comply with BS 3892:Part 1 except as specified herein.

20.3.3 Aggregates

(a) Fine aggregate shall be clean, hard, durable crushed rock, or natural sand,

complying with BS 882 except as specified herein. (b) Coarse aggregate shall be clean, hard, durable crushed rock complying with

BS 882.

20.3.4 Admixtures (a) Admixtures shall comply with the following:

(i) Pigments for Portland cement and Portland cement products : BS 1014 (ii) Accelerating admixtures, retarding admixtures and water-reducing admixtures : BS 5075:Part 1 (iii) Superplasticising admixtures : BS 5075:Part 3 (iv) Corrosion inhibitor admixtures : BS 5075 Part 1 : 1982 or STMC -494 Type C


20.4 DESIGN & PERFORMANCE CRITERIA

20.4.1 Concrete Mix

(a) Concrete shall be a designed mix unless the Project Manager reviews without objection the use of a standard or prescribed mix. Designed mixes shall be designed by the Contractor. The Contractor shall select the mix proportions with due regard to workability, strength, durability, temperature control and other requirements stated in the Specifications and on the Employer's Drawings. Prescribed mixes shall be in accordance with the requirements of the Hong Kong Building (Construction) Regulations.

(b) The minimum design slump value for designed mix concrete for reinforced

elements, after the addition of superplasticiser if used, shall be as shown in Table 20.1. Should the Contractor wish to use designed mix concrete with a design slump value less than that shown in Table 20.1 in reinforced elements, the Contractor shall submit his proposal to the Project Manager for review without objection to demonstrate that such concrete can be satisfactorily placed and compacted in trial sections simulating the appropriate sections of the Works.

(c) Cement, PFA, aggregates, water and admixtures for concrete shall comply

with Clauses 20.5.1 to 20.5.5. All-in aggregate shall not be used. (d) SRPC shall only be used if stated in the Contract. PFA shall not be used with

SRPC. (e) PFA shall not be used in addition to PPFAC. (f) Microsilica admixtures shall be used in conjunction with water reducing

admixtures. (g) Corrosion inhibitor admixtures shall be added separately with other

admixtures.

Table 20.1 : Workability

Degree of Workability

20 mm max. size

aggregate

40 mm max. size

aggregate Uses of which Concrete is

suitable Slump (mm) Slump (mm)

Low 12-25 25-50 Simply reinforced large sections with vibration

Medium 25-50 50-100 Moderately reinforced sections with vibration, such as ordinary beams and slabs

High 50-125 100-175 Sections with heavily congested reinforcement where vibration is difficult


20.4.2 Chloride and Sulphate Content of Concrete

(a) The maximum total chloride content of concrete, expressed as a percentage relationship between the chloride ion and the cementitious content by mass in the concrete mix, shall be as stated in Table 20.2. If the concrete is of more than one of the types stated, then the lower value of maximum chloride content shall apply.

(b) The total acid-soluble sulphate content of the concrete mix, expressed as

SO3, shall not exceed 4% SO3 by weight of the cement in the mix. The sulphate content should be calculated as the various constituents of the mix. The 4% limit does not apply to concrete made with supersulphated cement complying with BS 4248.

Table 20.2: Maximum Total Chloride Content of Concrete

Type of concrete Maximum total

chloride content (%)

Prestressed concrete. Steam-cured structural concrete

0.1

Concrete with reinforcement or other embedded metal and made with ordinary or rapid hardening Portland cement.

0.35

Concrete made with SRPC 0.2

20.4.3 Cementitious Content of Designed Mix Concrete

(a) The minimum cementitious content of designed mix concrete of Grade 20 or above using 20 mm nominal maximum aggregate size shall be as stated in Table 20.3, the minimum cementitious content shall be increased by 40 kg/m³ for 10 mm nominal maximum aggregate size and decreased by 30 kg/m³ for 40 mm nominal maximum aggregate size.

(b) Except as otherwise stated on the Employer's Drawings, the maximum

cementitious content of any mix shall be 550 kg/m³ and the maximum cement content of any mix shall be 440 kg/m³.

(c) The maximum cementitious content of designed mix concrete for water

retaining structures and watertight structures shall be 400 kg/m³ for concrete containing OPC and shall be 450 kg/m³ for concrete containing either OPC and PFA or PPFAC. The maximum cementitious content of designed mix concrete other than for water retaining structures and water tight structures shall be 550 kg/m³.

(d) The cementitious content of designed mix concrete may be varied during

routine production at the discretion of the Contractor by an amount not exceeding 20 kg/m³, provided that the total cementitious content is not less than the specified minimum value and does not exceed the specified maximum value.


(e) When PFA is incorporated in the concrete as a separate material, at least 75% of the specified minimum cementitious content shall be OPC.

(f) The designed free-water/cementitious material ratio of designed mixes shall

not exceed:

(i) 0.40 for concrete of Grade 40 or above;

(ii) 0.45 for concrete of Grade 30; and

(iii) 0.60 for concrete below Grade 30.

(g) When microsilica and corrosion inhibitor admixtures are incorporated in the concrete, mixing water used in the designed mix shall be adjusted in accordance with the manufacturer’s recommendations.

(h) For prestressed concrete, the minimum cementitious content shall be 360

kg/m3 for 10 mm nominal maximum aggregate size and 300 kg/m3 for 40 mm nominal maximum aggregate size.

Table 20.3 : Minimum Cementitious Content of Designed Mix concrete of

Grade 20 or Greater with 20mm Nominal Maximum Aggregate Size

Grade strength (MPa) 20 25 30 35 40 45 50

Minimum cementitious content (kg/m3) 290 290 310 330 350 375 400

20.4.4 Standard Mix Concrete

Standard mix concrete shall comply with the following requirements: (a) cement shall be OPC or PPFAC; (b) the total mass of dry aggregate to be used with 100 kg of OPC or with 110 kg

of PPFAC shall be as stated in Table 20.4; (c) the percentage by mass of fine aggregate to total aggregate shall be as stated

in Table 20.5; and (d) admixtures other than water-reducing admixtures shall not be used unless

reviewed without objection by the Project Manager.


Table 20.4 : Mass of Total Aggregate for Standard Mix Concrete

Grade Strength

(MPa)

Nominal maximum aggregate size

(mm) 40 20 10

Slump value (mm) 85 –170 75 – 150 65 – 130 10

Mass of total aggregate (kg)

800 690 - 20 550 500 400 25 490 440 360 30 440 380 300

Table 20.5 : Percent by Mass of Fine Aggregate to Total Aggregate for

Standard Mix Concrete

Grade strength

(MPa)

Grading of fine aggregate

(BS 882: Table 5)

Nominal maximum

aggregate size (mm)

40 20 10

10 C, M or F Percentage by mass

of fine aggregate to total aggregate

(%)

30 - 45 35 - 50 -

20, 25 or 30

C 30 - 40 35 - 45 45 - 55 M 25 - 35 30 - 40 40 - 50 F 25 - 30 25 - 35 35 - 45

20.4.5 No-fines Concrete

(a) No-fines concrete shall comply with the following requirements:

(i) cement shall be OPC or PPFAC;

(ii) the nominal maximum aggregate size shall be 20 mm; not more than 15% by mass shall be retained on a 20 mm BS test sieve and not more than 10% by mass shall pass a 10 mm BS test sieve;

(iii) aggregate/cement ratio by mass shall be at least 10 and shall not

exceed 15; and

(iv) the cement content shall be such that each particle of aggregate is coated with cement paste but the compacted concrete has an open texture which permits the flow of water through the hardened concrete.

(b) If the Project Manager requires cubes to be made of the no-fines concrete,

these shall be prepared and cured in accordance with the instructions given in BS 1881: Part 113 and shall achieve a strength of 10 MPa when crushed.

(c) No-fines concrete shall be placed with the minimum of punning. No traffic

shall be allowed on the finished work and the surface shall be kept clean. (d) Before placing normal concrete over no-fines concrete a layer of polyethylene

sheet of 500 grade or 0.5 mm thickness shall be laid over it and it shall be well lapped to ensure that no mortar from the overlying concrete penetrates to the no-fines concrete.


20.5 MATERIALS 20.5.1 Materials Permitted

(a) The only materials permitted to be used to make concrete are:

(i) cement; (ii) pulverised fuel ash; (iii) natural stone aggregates including crushed rock and natural sand; (iv) liquid admixtures reviewed without objection by the Project Manager ;

and (v) water.

(b) Exceptionally special additives such as silica fume or ground granulated blast

furnace slag may be required to be incorporated in mixes, but if so required this will be specified in the Specification.

(c) All materials used in concrete shall be fully identified and shall be traceable to

their sources of extraction or manufacture.

(d) Cement shall comply with the following:

(i) Ordinary and rapid hardening Portland cement : BS 12 : 1996 (ii) Sulphate resisting Portland cement : BS 4027 (iii) Portland pulverised-fuel ash cement (PPFAC) : BS 6588.

(e) Portland cements having a tricalcium aluminate (C3A) content for the previous 6 months production, which when calculated according to the procedure given in ASTM-C-150 exceeds either 11.5% for any individual test result or an average value of 11.0% shall not be used.

(f) The PFA content of PPFAC shall not exceed 25% by mass of the PPFAC.

20.5.2 PFA

PFA shall comply with BS 3892:Part 1 except that the criterion for maximum water requirement shall not apply.

20.5.3 Aggregates

(a) Aggregates shall be obtained from a source reviewed without objection by the Project Manager.

(b) Fine aggregate shall be clean, hard, durable crushed rock, or natural sand,

complying with BS 882, except that the note in Table 5 of BS 882 shall not apply.

(c) Coarse aggregate shall be clean, hard, durable crushed rock complying with

BS 882. The ten percent fines value shall be at least 100 kN. The water absorption shall not exceed 0.8%. The flakiness index shall not exceed 35%.


20.5.4 Water

(a) Water for concrete and for curing concrete shall be clean, uncontaminated and from a source reviewed without objection by the Project Manager. The Contractor shall test water proposed to be used to produce concrete in accordance with the requirements of Clause 20.8.3.

(b) The use of recycled water for concrete is not permitted.

20.5.5 Admixtures

(a) Admixtures will normally only be permitted if they are liquids and they shall be measured by volume or weight. If the Project Manager has reviewed without objection the use of a solid or paste admixture this shall be thoroughly dispersed or dissolved in at least 10 times its weight of water so that it will be distributed uniformly in the concrete before any concrete is placed. The water used for dispersing the admixture shall be considered as part of the mixing water in the concrete and shall be included in the calculation of the water/cement ratio of the concrete.

(b) Admixtures shall comply with the following:

(i) Pigments for Portland cement and Portland cement products : BS 1014 (ii) Accelerating admixtures, retarding admixtures

and water-reducing admixtures : BS 5075:Part 1 (iii) Superplasticising admixtures : BS 5075:Part 3 (iv) Corrosion inhibitor admixtures : BS 5075:Part 1 : 1982 or ASTMC -494 Type C

(c) The chloride ion content of admixtures for concrete containing embedded

metal or for concrete made with SRPC shall not exceed 2% by mass of the admixture or 0.03% by mass of the cementitious content, whichever is less.

20.5.6 Curing Compound

(a) Curing compounds shall be a proprietary type reviewed without objection by the Project Manager and shall have an efficiency index of at least 80%.

(b) Curing compounds shall contain a fugitive dye. Curing compounds containing

organic solvents shall not be used. The curing compound shall become stable and achieve the specified resistance to evaporation of water from the concrete surface within 60 minutes after application. Curing compounds shall not react chemically with the concrete to be cured and shall not crack, peel or disintegrate within one week after application. Curing compounds shall degrade completely within three weeks after application and the concrete surface so treated shall not impair the bonding of applied finishes.

(c) Curing compounds for use on concrete surfaces against which potable or

fresh water will be stored or conveyed shall be non-toxic and shall not impart a taste to the water.


20.5.7 Materials for Joints in Water Retaining Structures and Water Tight Structures (a) Materials for joints in water retaining structures and water tight structures for

sewage shall be resistant to aerobic and anaerobic bacteriological attack and to attack by petrol, diesel oil, dilute acids and alkalis.

(b) Materials for joints in water retaining structures for potable and fresh water

shall be non-toxic and shall not impart taste and colour to the water. 20.5.8 Joint Filler

Joint filler shall be a proprietary type reviewed without objection by the Project Manager and shall be a firm, compressible, single-thickness, non-rotting filler. Joint filler for joints in water retaining structures and watertight structures shall be non-absorbent.

20.5.9 Bitumen Emulsion

Bitumen emulsion for joints in water retaining structures and watertight structures shall comply with BS 3416. Bitumen emulsion for surfaces against which potable or fresh water will be stored or conveyed shall comply with BS 3416, Type II.

20.5.10 Joint Sealant

(a) Joint sealant shall be a grade suited to the climatic conditions of Hong Kong and shall perform effectively over a temperature range of 0°C to 60°C. The colour of all sealants in exposed areas shall be reviewed without objection by the Project Manager. Joint sealant for exposed joints in water retaining structures shall be grey.

(b) Joint sealant other than cold-applied bitumen rubber sealant shall be:

(i) a gun grade for horizontal joints 15 mm wide or less and for vertical and

inclined joints; and

(ii) a pouring grade for horizontal joints wider than 15 mm.

(c) Polysulphide-based sealant shall be a cold-applied two-part sealant complying with BS 4254. Polysulphide-based sealant for expansion joints in water retaining structures shall have a transverse butt-joint movement range of at least 20%.

(d) Polyurethane-based sealant shall be a cold-applied two-part sealant

complying with the performance requirements of BS 4254. (e) Hot-applied bitumen rubber sealant shall comply with BS 2499, Type A1. (f) Cold-applied bitumen rubber sealant shall be a proprietary type reviewed

without objection by the Project Manager. (g) Joint sealant for joints in water retaining structures and watertight structures

shall be as stated in Table 20.6.


(h) Primers and caulking material for use with joint sealant shall be a proprietary type recommended by the joint sealant manufacturer and reviewed without objection by the Project Manager.

(i) Different types of joint sealant and primers which will be in contact, shall be

demonstrated as being compatible.

Table 20.6: Joint Sealant for Water Retaining Structures and Water Tight Structures

Type of water retaining

structure Type of joint Type of joint sealant

Sewage All joints Polyurethane-based

Other than sewage

Expansion joints Polysulphide-based

Horizontal joints other than expansion joints

Hot-applied bitumen rubber

Vertical and inclined joints other than expansion joints

Polysulphide-based or cold-applied bitumen rubber

20.5.11 Bond Breaker Tape

Bond breaker tape shall be a proprietary type recommended by the joint sealant manufacturer and reviewed without objection by the Project Manager. The tape shall be a polyethylene film with adhesive applied on one side and shall be the full width of the groove.

20.5.12 Strip and Pad Bearings

(a) Strip bearings shall be used where specified on the Employer's Drawings. The preferred type of bearings shall consist of a polished stainless steel sliding against a P.T.F.E. coated natural rubber strip blocked out either side with expanded polystyrene spacer strips. Bearings shall be continuous over the length of joint as indicated on the Employer's Drawings. Other proprietary types of strip bearings may be submitted for review without objection by the Project Manager.

(b) Pad bearings shall be used where specified on the Employer's Drawings. The

preferred type of bearings shall consist of a stainless steel top plate roughened on the upper surface and polished on the lower, sliding against a P.T.F.E. coated natural rubber/reinforced rubber pad, blocked out all around with expanded polystyrene spacer blocks. Bearings shall be placed at the centres indicated on the Employer's Drawings. Other proprietary types of pad bearings may be submitted for review without objection by the Project Manager.

20.5.13 Waterstops

(a) Waterstops, including intersections, reducers and junctions, shall be a proprietary type reviewed without objection by the Project Manager, or as shown on the Employer's Drawings and shall be natural or synthetic rubber or extruded polyvinyl chloride with the properties stated in Table 20.7.


(b) Unless otherwise stated on the Employer's Drawings, the size of waterstops shall be as follows:

Wall or Slab Thickness (mm) Waterstop Size (mm) ≥ 250 250 200 - 250 200 < 200 150

(c) Hydrophilic waterstops shall be installed where shown on the Employer's Drawings. They shall be made from a preformed elastomeric strip which can integrate into existing waterstop networks and shall be free from rubber, bentonite or other inclusions. The waterstop shall have an unrestrained volumetric expansion of not less than 170% and must not deteriorate under prolonged wet/dry cycling and must be able to withstand a hydrostatic head of 50 m. The waterstop shall be installed in accordance with the manufacturer's instructions.

Table 20.7: Properties of Waterstops

Property Rubber waterstops PVC waterstops

Density 1100 kg/m³ (± 5%) 1300 kg/m³ (± 5%)

Hardness 60 - 70 IRHD 70 - 90 IRHD

Tensile strength ≥ 20 N/mm² ≥ 13 N/mm²

Elongation at break point ≥ 450% ≥ 285%

Water absorption ≤ 5% by mass after 48 hours immersion

≤ 0.15% by mass after 24 hours immersion

Softness number - 42 – 52

20.6 SUBMISSIONS 20.6.1 Particulars of Materials for Concrete

(a) The following particulars of the proposed cement, PFA and aggregates shall be submitted to the Project Manager for review without objection:

(i) a certificate applicable to the material to be supplied and not older than

6 months for each type of cement showing the manufacturer's name, the date and place of manufacture and showing that the cement complies with the requirements stated in the Contract and including results of tests for:

• chemical composition; • fineness; • compressive strength at 3, 7 and 28 days; • initial and final setting times; • soundness; and • proportion by mass of PFA contained in PPFAC.


(ii) a certificate applicable to the material to be supplied and not older than 6 months for PFA showing the source of the PFA and showing that the PFA complies with the requirements stated in the Contract and including results of tests for:

• chemical composition; • fineness; and • moisture content.

(iii) a certificate applicable to the material to be supplied and not older than

6 months for each nominal maximum aggregate size showing the source of the aggregate and showing that the aggregate complies with the requirements stated in the Contract and including results of tests for:

• grading; • silt content; • chloride content; • flakiness index of coarse aggregate; • ten percent fines value; and • water absorption.

(b) The following particulars of the proposed admixtures shall be submitted to the

Project Manager for review without objection:

(i) manufacturers' literature;

(ii) description of physical state, colour and composition;

(iii) recommended storage conditions and shelf life;

(iv) method of adding to the concrete mix;

(v) any known incompatibility with other admixtures or cement;

(vi) recommended dosage;

(vii) effects of under-dosage and over-dosage; and

(viii) a certificate which is applicable to the material to be supplied and not older than 6 months for each type of admixture showing the manufacturer's name, the date and place of manufacture and showing that the admixture complies with the requirements stated in the Contract and including results of tests for:

• uniformity; • chloride content; and • details of toxicity.


(c) The following particulars of the proposed curing compound shall be submitted to the Project Manager for review without objection:

(i) manufacturer's literature;

(ii) description of physical state, colour and composition;

(iii) recommended storage conditions and shelf life;

(iv) method of application;

(v) recommended rate of application; and

(vi) a certificate showing the manufacturer's name, the date and place of

manufacture and showing that the curing compound complies with the requirements stated in the Contract and including results of tests for efficiency index.

20.6.2 Particulars of Concrete Mix

(a) The following particulars of each proposed designed concrete mix shall be submitted to the Project Manager for review without objection:

(i) quantity of each constituent per batch and per cubic metre of

compacted concrete, with required tolerances on quantities of aggregates to allow for minor variations in grading, silt content etc. The maximum permitted variation in the quantity of fine aggregate shall be ± 20 kg of fine aggregate per 100 kg of cement;

(ii) type and source of cement and PFA;

(iii) type and quantity of admixture;

(iv) the type and source of fine and coarse aggregates;

(v) grading details in tabular and graphical form of coarse and fine

aggregates, including combined grading curves; and

(vi) grading details, in tabular and graphical form, of the combined aggregates, together with details of the proportions in which the fine and coarse aggregates are to be combined;

(vii) workability in terms of designed slump value before and after the

addition of superplasticisers;

(viii) method of placing concrete;

(ix) method of controlling the temperature of the concrete, if required;

(x) test or trial mix data for designed mix concrete of the same Grade and with similar constituents and properties, if available;

(xi) test data for designed mix concrete of the same or other grade produced in the plant or plants proposed to be used, if available; and

(xii) total chloride ion content of the mix.


20.6.3 Particulars of Ready-mixed Concrete Supplier

(a) The name of the suppliers and the location of each plant, including a back-up plant, from which the Contractor proposes to obtain ready-mixed concrete shall be submitted to the Project Manager at least 14 days before trial mixes are made or, if trial mixes are not required, at least 30 days before the ready-mixed concrete is programmed to be placed in the Permanent Works.

(b) The plant producing the concrete shall be operated in accordance with the Quality Scheme for the Production and Supply of Concrete (QSPSC) of the Hong Kong Quality Assurance Agency (HKQAA).

(c) Ready mix concrete shall be as defined in BS 5328.

20.6.4 Particulars of Batching and Mixing Plant

Particulars of the proposed batching and mixing plant to be used on Site, including a layout plan and the output of the plant, shall be submitted to the Project Manager for review without objection at least 28 days before the plant is delivered to Site.

20.6.5 Particulars of Precast Concrete Units

(a) The method of manufacture of precast concrete units on or off Site shall be reviewed without objection by the Project Manager before work commences. No changes shall be made thereafter without prior review without objection by the Project Manager.

(b) The following particulars of the proposed precast concrete units shall be

submitted to the Project Manager for review without objection:

(i) Contractor’s Drawings showing the full details of the elements including dimensions, fixings, lifting points, reinforcement and chases;

(ii) method of manufacture which must include details of :

• place of manufacture; • proposed formwork systems and materials; • method of placing and compacting concrete; • method of curing concrete; • proposed quality control procedures; and • details of lifting points and methods of handling;

(iii) date of commencement of manufacture and casting of each type of

member;

(iv) details of precasting yards;

(v) procedure for testing precast units;

(vi) not more than seven days after the transfer of stress, a certificate showing the force and extension in the tendons after anchorage, the strength and age of the test cubes cast as described in this section and the minimum age in hours of the concrete at the time the stress was applied to the member; and


(vii) a certificate showing the manufacturer's name, the date and place of manufacture, the identification number of the precast concrete units and including results of tests for:

• compressive strength of concrete cubes at 28 days; and • routine tests, including loading tests, carried out at the precast yard;

(c) The following particulars of the constructed precast concrete units shall be submitted to the Project Manger for onward submission to the Buildings Department: (i) the date and place of manufacture, the identification numbers of the

precast concrete units and including results of tests for compressive strength of concrete cubes at 28 days tested by a HOKLAS accredited testing laboratory;

(ii) a detailed method statement including the design, drawings and

installation procedures for all the temporary support works for erection of the precast concrete elements;

(iii) the names and qualifications of the supervisory personnel supervising

the fabrication, erection and examination of the precast concrete units; and

(iv) a copy of the site log book recording the date and time of inspections

and details of Site activities. 20.6.6 Particulars of Construction Joints

Particulars of the proposed positions and details of construction joints in concrete shall be submitted to the Project Manager for review without objection. This submission shall include details of any material which is to remain permanently in the Works as part of forming the joint.

20.6.7 Particulars of AAR in Concrete

(a) The following particulars of the proposed concrete mix shall be submitted to the Project Manager for review without objection:

(i) HOKLAS endorsed test certificates not older than 6 months giving the

results of tests required in Section 20.8.4(c)(ii) to (vi); and (ii) calculation of the reactive alkali of the proposed mix.

(b) New HOKLAS endorsed test certificates giving the results of tests required in

Section 20.8.4(c)(ii) to (vi) shall be submitted at quarterly intervals together with any necessary further calculations to demonstrate that the mix continues to comply with the limit on reactive alkali.


20.6.8 Trial Mix Concrete

(a) Trial mixes are not required for designed mix concrete of Grade 20 and below, for standard mix concrete or for prescribed mix concrete.

(b) If test data for designed mix concrete of the proposed Grade and with similar

constituents and properties and produced in the plant or plants proposed to be used are submitted in accordance with Section 20.6.2, and are reviewed without objection by the Project Manager, no trials for that designed mix will be required.

(c) If test data for designed mix concrete of the proposed Grade and with similar

constituents and properties produced in plant other than that proposed to be used are submitted in accordance with Section 20.6.2, and are reviewed without objection by the Project Manager, the Project Manager may require plant trials to be carried out in accordance with Section 20.6.9.

(d) If test data for designed mix concrete produced in the plant or plants proposed

to be used, but of a Grade or with constituents and properties other than those proposed, are submitted in accordance with Section 20.6.2, and are reviewed without objection by the Project Manager, the Project Manager may require laboratory mix trials to be carried out in accordance with Section 20.6.10.

(e) If no test data for designed mix concrete are submitted or if test data

submitted in accordance with Section 20.6.2 does not in the opinion of the Project Manager demonstrate the suitability of the proposed plant and mix design, the Project Manager may require both plant trials and laboratory mix trials in accordance with Sections 20.6.9 and 20.6.10 respectively.

(f) Plant trials and laboratory mix trials shall be completed at least 35 days before

the concrete mix is programmed to be placed in the Permanent Works. (g) The Contractor shall notify the Project Manager before conducting plant trials

or laboratory mix trials. 20.6.9 Plant Trials

(a) Plant trials shall be made using the plant or plants proposed and the mix designs and constituents submitted to and reviewed without objection by the Project Manager.

(b) One batch of concrete of a proposed designed mix shall be made on each of

three days in each plant proposed to be used. The batch shall be at least 60% of the mixer's nominal capacity. If the concrete is batched in a central plant and mixed in a truck mixer, three different truck mixers shall be used.

(c) Three samples of concrete shall be provided from each batch at

approximately 1/6, 1/2 and 5/6 of the discharge from the mixer. Each sample shall be of sufficient size to perform a slump test and make two 150 mm test cubes. The method of sampling shall be as stated in CS1.


(d) Each sample taken in accordance with Section 20.6.9(c) shall be tested to determine its slump value in accordance with CS1.

(e) Two 150 mm test cubes shall be made from each of the three samples taken

in accordance with Section 20.6.9(c) and stored, cured and tested to determine the compressive strength at 28 days in accordance with CS1.

20.6.10 Laboratory Mix Trials

(a) Laboratory mix trials shall be made in the Contractor's laboratory using the mix designs and constituents submitted to and reviewed without objection by the Project Manager.

(b) Laboratory mix trials shall be carried out in accordance with Section 11 of

CS1. Three separate batches shall be made, each of sufficient size to provide samples for two slump tests and to make six 150 mm test cubes.

(c) Two slump tests in accordance with CS1 shall be performed on separate

specimens from each batch of laboratory trial mix concrete. (d) Six 150 mm test cubes shall be made from each batch of laboratory trial mix

concrete, stored, cured and tested for compressive strength at 28 days in accordance with CS1.

20.6.11 Compliance Criteria : Plant trials

(a) The results of tests on concrete taken from plant trials in accordance with Section 20.6.9 shall comply with the following requirements :

(i) the average of the three slump values shall be within 20mm or 25%,

whichever is the greater, of the designed slump value;

(ii) the range of the three slump values for each batch of concrete shall not exceed 20% of the average of the three slump values for that batch;

(iii) the average compressive strength at 28 days of the 6 test cubes shall

exceed the Grade strength by at least 10 MPa and the compressive strength of each individual test cube shall exceed the Grade strength by at least 4 Mpa; and

(iv) the range of the compressive strength of the six test cubes from each

batch of concrete shall not exceed 20% of the average compressive strength of the six test cubes from that batch.

20.6.12 Compliance Criteria: Laboratory Mix Trials

(a) When test data relating to the proposed plant or plants submitted in accordance with Section 20.6.2 show that the plant standard deviation exceeds 5 MPa, or in the absence of acceptable data, the results of tests on laboratory trial mix concrete shall comply with the following requirements:

(i) the average of the six slump values shall be within 20 mm or 25%,

whichever is the greater, of the design slump value; and


(ii) the average compressive strength at 28 days of the 18 test cubes shall exceed the Grade strength by at least 12 MPa and the compressive strength of each individual test cube shall exceed the Grade strength by at least 6 MPa.

(b) When test data relating to the proposed plant or plants submitted in

accordance with Section 20.6.2 show that the plant standard deviation does not exceed 5 MPa, the results of tests on laboratory mix trial concrete shall comply with the following requirements :

(i) the average of the six slump values shall be within 20 mm or 25%,

whichever is the greater, of the design slump value; and

(ii) the average compressive strength at 28 days of the 18 test cubes shall exceed the Grade strength by at least 8 MPa and the compressive strength of each individual test cube shall exceed the Grade strength by at least 2 MPa.

20.6.13 Trial Lengths and Trial Panels

Trial lengths required in accordance with Sections 10.5.2 to 10.5.5 and trial panels required in accordance with Sections 18.5.2 and 18.5.3 shall be constructed for each concrete mix as appropriate.

20.6.14 Non-compliance: Trial Mix Concrete

(a) If the result of any test for workability or compressive strength of laboratory mix trial and plant trial concrete does not comply with the specified requirements for the property, particulars of proposed changes to the materials, mix design or methods of production shall be submitted to the Project Manager for review without objection. Further laboratory mix trials or plant trials shall be made until the result of every test complies with the specified requirements for workability and compressive strength of laboratory mix trial and plant trial concrete.

(b) If trial lengths or trial panels are constructed using the non-complying trial mix,

further trial lengths or trial panels shall be constructed.

20.6.15 Acceptable Concrete Mix

(a) A concrete mix which complies with the specified requirements for laboratory mix trials, plant trials and for trial lengths or trial panels is defined as an "Acceptable Concrete Mix". The designed slump value used to produce an "Acceptable Concrete Mix" shall become the "Acceptable Slump Value".

(b) If laboratory mix trials or plant trials are not required, a concrete mix submitted

as stated in Section 20.6.12 and which complies with the specified requirements for trial lengths or trial panels shall become an "Acceptable Concrete Mix". The designed slump value of the concrete mix shall become the "Acceptable Slump Value".


20.6.16 Records of Concrete

(a) Each delivery of concrete to Site shall be accompanied by a certificate giving full details of its origin and composition. The weights of materials in each batch of concrete shall be recorded automatically by the batching equipment and the printed records shall be available to the Project Manager for inspection at all times. Manually prepared records of batch composition are not acceptable. Delivery notes shall contain the following details:

(i) serial number of delivery note;

(ii) date and time of loading;

(iii) name and location of batching and mixing plant;

(iv) registration number of delivery vehicle;

(v) name of purchaser;

(vi) name and location of the Site;

(vii) designation of concrete mix and "Acceptable Slump Value";

(viii) type name and quantity of admixture;

(ix) quantity of concrete;

(x) quantity of water in litres per cubic metre of concrete and the time of

introduction of water to the concrete;

(xi) moisture content of fine aggregate and amount of water subtracted from the batch quantities to compensate for this;

(xii) type of cementitious material, weight in kilograms per cubic metre of

concrete and time of introduction to the concrete mix; and

(xiii) type of aggregate and weights of fine and coarse aggregates in kilograms per cubic metre of concrete.

(b) Records of concreting operations shall be kept by the Contractor on Site.

Records shall contain the following details:

(i) date;

(ii) designation of concrete mix and "Acceptable Slump Value";

(iii) total quantity of each concrete mix produced that day;

(iv) serial number of delivery note;

(v) arrival time of delivery vehicle;

(vi) time of completion of discharge;

(vii) position where concrete was placed;


(viii) results of slump tests;

(ix) details of test cubes made; and

(x) temperature of concrete.

(c) The Contractor shall submit to the Project Manager for review without objection a statement covering the method of placing concreting at any one location. The statement shall cover all items of plant to be used and their respective layout and shall include the extent of bays, sequence of concreting and proposals for stop ends. With respect to concrete temperature, the Contractor shall submit to the Project Manager for review without objection a detailed method statement of his proposed temperature control and monitoring strategy and the substantiation of this strategy. The information to be submitted shall include, but shall not be limited to, the following:

(i) concrete mix details including heat of hydration and specific heat

characteristics of the proposed constituents;

(ii) formwork type and insulation;

(iii) curing details related to temperature effects; and

(iv) calculations of the forecast concrete temperature, temperature gradients and resulting stresses. The calculation of temperature in concrete shall be in accordance with the Construction Industry Research and Information Association Report No. 91, "Early Age Thermal Crack Control in Concrete"

20.6.17 Particulars of Materials for Joints

(a) The following particulars of the proposed materials for joints shall be submitted to the Project Manager for review without objection:

(i) manufacturer's literature and a certificate for joint filler showing the

manufacturer's name, the date and place of manufacture and showing that the joint filler complies with the requirements stated in the Contract and including results of tests for;

• disintegration and shrinkage; • recovery value and reduction in mass; and • extrusion;

(ii) manufacturer's literature and a certificate for bitumen emulsion showing the manufacturer's name, the date and place of manufacture and showing that the bitumen emulsion complies with the Specification;

(iii) manufacturer's literature for joint sealant, including details of the method

and time required for mixing the different components, and a certificate showing the manufacturer's name, the date and place of manufacture and showing that the sealant complies with the Specification and including results of tests as appropriate for:

• rheological properties; • plastic deformation; • adhesion and tensile modulus;


• application life; • adhesion in peel; • loss of mass after heat ageing; • staining; • transverse butt joint movement range; • extension; • flow; • penetration; • degradation; and • fire rating, where appropriate;

(iv) manufacturer's literature and a certificate for strip and pad bearings for

sliding joints showing the manufacturer's name, the date and place of manufacture and showing that the strips comply with the Specification and including results of tests for:

• vertical load; • coefficient of friction; and • a descriptions of the method of installation of bearings;

(v) manufacturer's literature for waterstops, including details of

intersections, reducers and junctions, and a certificate showing the manufacturer's name, the date and place of manufacture and showing that the waterstops comply with the requirements stated in the Contract and including results of tests for:

• density; • hardness; • tensile strength; • elongation at break point; • water absorption; • softness number of PVC waterstops; and • hydrophilic properties, where appropriate; and

(vi) particulars of primers and caulking material for joint sealant and of bond

breaker tape. 20.6.18 Representative Samples of Materials

(a) Representative samples of the following proposed materials shall be submitted to the Project Manager at the same time as particulars of the material are submitted:

(i) joint filler and joint sealant;

(ii) bond breaker tape;

(iii) bearing strip for sliding joints; and

(iv) waterstops, including intersections, reducers and junctions.


20.7 WORKMANSHIP 20.7.1 Storage of Cement and PFA

(a) Cement in bags shall be stored in a dry, weatherproof store with a raised floor. Each delivery shall be identified and kept separate and shall be used in the order of delivery.

(b) Bulk cement and PFA shall be stored in dry, weatherproof silos. Cement and

PFA of different types and from different sources shall be stored in separate silos clearly marked to identify the different contents of each.

(c) The loading, unloading, transfer, handling or storage of bulk cement or dry

PFA during or after the debagging process must be done in a totally enclosed system or facility. Any vent or exhaust shall be fitted with fabric filter or equivalent air pollution control system or equipment.

(d) Consignments of cement and PFA shall be used in order of delivery. Any

cement stored for longer than one month shall be re-tested for moisture content, soundness and setting time. Any PFA stored for longer than one month shall be re-tested for moisture content.

20.7.2 Handling and Storage of Aggregates

(a) Aggregates shall not be handled or stored in a manner which will result in mixing of the different types and sizes or in segregation or contamination of the aggregates.

(b) Different types and sizes of aggregates shall be stored in separate hoppers or

in separate stockpiles. The stockpiles shall have well drained concrete floors and shall have dividing walls of sufficient height to keep the different aggregates separate.

20.7.3 Storage of Admixtures and Curing Compounds

Admixtures and curing compounds shall be stored in sealed containers marked to identify the contents and protected from exposure to conditions which may affect the material. The materials shall be stored in accordance with the manufacturers' recommendations and shall not be used after the recommended shelf life has been exceeded.

20.7.4 Handling and Storage of Precast Concrete Units

(a) The identification number, date of casting and lifting points shall be marked on precast concrete units in a manner reviewed without objection by the Project Manager.

(b) Precast concrete units shall be lifted and supported only at the designed lifting

points and shall not be subjected to rough handling, shock loading or dropping.

(c) Precast concrete units shall be stored off the ground on level supports and in

a manner which will not result in damage or deformation to the units or in contamination of the units. Precast concrete units shall be protected from damage and damaged units shall not be used in the Permanent Works.


(d) At all stages of construction, precast concrete units and other associated concrete shall be adequately protected to prevent damage to permanently exposed concrete surfaces, particularly any decorative features.

(e) Precast units shall not to be lifted until at least 24 hours after casting or until

concrete has attained a strength adequate to resist the resultant stresses without inducing cracking or other damage to the concrete.

20.7.5 Batching Concrete

(a) Concrete shall be produced at a plant certified, registered and operated in accordance with the Quality Scheme for the Production and Supply of Concrete (QSPSC) of the Hong Kong Quality Assurance Agency (HKQAA). The requirements of the Specification shall prevail over those of the QSPSC.

(b) Measuring and weighing equipment for batching concrete shall be maintained

in a clean, serviceable condition and their accuracy shall be maintained within the tolerances given in BS 1305. The equipment shall be checked regularly at intervals reviewed without objection by the Project Manager and at a minimum in accordance with the requirements of Appendix A20.4, Part 1. The accuracy of the measuring equipment shall be within 3% of the quantity of cementitious materials, total aggregates or water being measured and within 5% of the quantity of admixtures being measured.

(c) The quantities of cement, PFA and fine and coarse aggregates shall be

measured by mass except that cement supplied in bags may be measured by using a whole number of bags in each batch. The mass of aggregates shall be adjusted to allow for the free moisture content of the aggregates.

(d) Separate weighing equipment shall be used for cementitious material and

aggregates. (e) The quantity of water shall be adjusted for the free moisture content of the

aggregates and shall be measured by mass or volume. (f) Liquid admixtures shall be measured by mass or volume and powdered

admixtures shall be measured by mass. 20.7.6 Mixing Concrete

(a) The quantities of concrete mixed and the speed of operation of a mixer shall comply with the manufacturer's recommendations.

(b) A mixer shall not be loaded in excess of its rated capacity and shall be

emptied before being re-charged. A mixer which has been out of use for more than 30 minutes shall be cleaned before fresh concrete is mixed in it. Mixers shall be cleaned whenever there is a change in the type of cement being used.

(c) Mixing times or the number and rate of revolutions of mixer drums shall be in

accordance with the recommendations of the manufacturer unless the Contractor can demonstrate otherwise. Constituents shall be thoroughly mixed and admixtures shall be uniformly distributed throughout the concrete.

(d) Water shall be added to truck mixed concrete at the batching plant and shall

not be added in transit or be added at Site.


(e) Superplasticising admixtures used with concrete mixed off Site shall be added

at Site.

(f) Water shall not be added to partially hardened concrete.

(g) Partially hardened concrete shall not be remixed, with or without additional cement, aggregate or water.

20.7.7 Transportation of Concrete

(a) Concrete shall not be transported in a manner which will result in contamination, segregation, loss of constituents or excessive evaporation.

(b) Concrete batched off Site shall be transported to Site in purpose-made

agitators operating continuously. (c) Where an agitator is used for transporting concrete, the discharge shall be

completed within a period reviewed without objection the Project Manager. The time of contact between cement and water shall be deemed to be the loading time recorded on the delivery ticket.

(d) Where concrete is transported in non-agitating equipment, discharge shall be

completed within a period reviewed without objection the Project Manager. The time at which mixing was completed shall be deemed to be the loading time recorded on the delivery ticket.

(e) Transportation equipment shall be checked regularly at intervals reviewed

without objection by the Project Manager in accordance with the requirements of Appendix A20.4, Part 2.

20.7.8 Commencement of Concreting

Concrete shall not be placed in the Permanent Works until the concrete mix has been reviewed without objection by the Project Manager.

20.7.9 Changes in Materials and Methods of Construction

The materials, mix design, methods of production or methods of construction used to produce an "Acceptable Concrete Mix" shall not be changed except that the variations of cement content as stated in Section 20.4.3(d), and variations in aggregate quantities within the permitted tolerances, will be allowed.

20.7.10 Concrete Placing and Temperature

(a) The Contractor shall notify the Project Manager before concrete is placed in any part of the Permanent Works, allowing sufficient time for the Project Manager to inspect the works which are to be concreted.

(b) Concrete shall be compacted in its final position within 1 hour of discharge

from the mixer unless carried in purpose made agitators, operating continuously, when the time shall be within 2½ hours of the introduction of cement to the mix and within 30 minutes of discharge from the agitator.

(c) Concrete which does not satisfy the compliance criteria for workability as

stated in Section 20.8.9 shall not be placed in the Permanent Works.


(d) Where it is necessary to deposit concrete under water, details of the methods, equipment, materials and proportions of the mixes to be used shall be submitted to the Project Manager for review without objection before the work is commenced. Where the concrete is placed by a tremie, its size and method of operation shall be in accordance with BS 8004. During and after concreting under water, pumping or dewatering operations in the immediate vicinity shall be suspended for a period which has been reviewed without objection by the Project Manager.

(e) All formwork and reinforcement contained within it shall be clean and free

from standing water immediately before the placing of the concrete. (f) Concrete shall be placed as close as practicable to its final position and shall

not be moved into place by vibration. Trunking or chutes shall be used to place concrete which would otherwise fall more than 2.0 m. When trunking or chutes are used they shall be kept clean and used in such a way as to avoid segregation.

(g) Concrete shall be placed in such a manner that the formwork, reinforcement

or built-in components are not displaced. (h) Concrete unless placed by tremie, shall be placed in horizontal layers to a

compacted depth of not more than 450 mm if internal vibrators are used and to a compacted depth of not more than 150 mm in other cases.

(i) Concrete shall be placed continuously within the element to be concreted.

Fresh concrete shall not be placed against concrete which has been in position for more than 30 minutes. Otherwise a construction joint shall be formed as stated in Section 20.7.14.

(j) Concrete shall not be placed in ground or water which has a temperature

below 5°C. (k) Where the ambient temperature is greater than 32°C full hot weather

concreting techniques as described in ACI document ACI 305R-89, Clauses 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 4.1, 4.2 and 4.3 shall be implemented.

(l) No concrete shall be placed in free-flowing water. Cofferdams or forms shall

be sufficiently tight to reduce the flow or current of water through the space where the concrete is to be deposited to a velocity or flow rate, reviewed without objection by the Project Manager. Cofferdams or forms in still water shall be sufficiently tight to prevent loss of mortar through the walls.

(m) Before concrete is placed on a rock foundation the rock surface shall be clean

and free from soft rock and loose rock, dust or other debris. The final cleaning shall be done with air and/or water jets and excavation with hand held tools.

(n) After the rock surface has been prepared and reviewed without objection by

the Project Manager and immediately before placing blinding or other concrete, the surface of the rock shall be covered with a layer of grout 6 mm thick. The grout shall have the consistency of a stiff paste and it shall be well brushed over the rock and into all crevices.


(o) The temperature of concrete at the time of placing shall be measured and controlled. The Contractor shall take measures to ensure that after placing, the maximum temperature attained in the concrete and the temperature gradient does not exceed specified levels.

(p) The temperature of concrete at the time of placing in the forms shall not be

more than 32°C. The Contractor shall submit details of the proposed measures to ensure that this temperature will not be exceeded.

(q) The temperature shall be measured by placing a calibrated probe-type

thermometer into the concrete at the time of discharge from the vehicle transporting it or not later than 15 minutes thereafter.

(r) The Contractor shall employ effective means such as pre-cooling the

aggregates and mixing water, as necessary, to maintain the temperature of the concrete below 32°C prior to placing.

(s) After concrete has been placed its temperature shall not be permitted to rise

above 70°C. (t) The maximum temperature gradient within any structure due to heat of

hydration taken at any two points one metre apart shall not exceed 15°C. Irrespective of the thickness of a section the maximum temperature differential between the core and the surface shall not exceed 20°C overall.

(u) Prior to laying slabs on ground a damp proof membrane shall be laid. The

damp proof membrane shall be a polythene sheet at least 0.3mm thick. Each sheet of damp proof membrane shall be lapped at least 300mm at the edges and sealed and taped to adjacent sheets. Sealing shall be achieved with double sided mastic tape or similar as recommended by the manufacturer. All punctures and tears shall be repaired prior to placing concrete.

(v) Damp proof membranes shall be lapped and sealed to vertical faces of walls

and slab edges by a minimum of 300mm or as shown on the Employer’s Drawings.

20.7.11 Placing Concrete by Pumping

(a) Concrete pumps shall be operated and maintained in accordance with the manufacturer's recommendations. The pumps and pipelines shall be maintained in a clean condition. Internal surfaces of pipelines shall not be aluminum. Joints in pipelines shall not permit grout loss.

(b) Concrete pumps shall be positioned such that pipelines are as short and

straight as practicable and require as little repositioning as practicable. Bends in pipelines shall be arranged in such a manner that the concrete, formwork, reinforcement or built-in components are not disturbed.

(c) Pipelines shall be lubricated by passing cement grout or concrete through the

pipeline before the Permanent Works concrete is pumped. This initial lubricating grout or concrete shall not be placed in the Permanent Works.


20.7.12 Placing Concrete by Tremie

(a) Tremies used to place concrete shall be securely supported in position and the joints shall be watertight. A temporary seal of a type reviewed without objection by the Project Manager shall be used to keep the water and the concrete separate at the start of concreting.

(b) After the concrete is flowing, the tremie shall be raised in a manner reviewed

without objection by the Project Manager; the lower end of the tremie shall be kept immersed in the concrete to a depth of at least 1 m. Water, mud and other deleterious material shall be prevented from entering the tremie after concreting has started.

(c) If the tremie becomes blocked or is removed from the concrete, concreting

shall be stopped immediately. Concreting shall not recommence for at least 24 hours; contaminated concrete shall be removed before concreting recommences.

(d) Concrete placed by tremie shall be placed above the specified level by an

amount to allow for the removal of concrete, including laitance and excess cement slurry. Contaminated concrete shall be removed.

20.7.13 Compacting Concrete

(a) Concrete shall be compacted to form a dense homogeneous mass. (b) Concrete shall be compacted by means of internal vibrators of suitable

diameter. A sufficient number of vibrators shall be maintained in serviceable condition on Site to ensure that spare equipment is available in the event of breakdown.

(c) Vibrators shall be used in such a manner that vibration is applied continuously

and systematically during placing of the concrete until the expulsion of air has practically ceased. Vibrators shall not be used in a manner which will result in segregation. Internal vibrators shall be inserted to the full depth of the concrete placed and shall be withdrawn slowly.

(d) Vibration shall not be applied by way of the reinforcement, and contact

between internal vibrators and formwork, reinforcement or built-in components shall be avoided as far as possible. Concrete shall be vibrated in such a manner that the formwork, reinforcement or built-in components shall not be displaced.

(e) Concrete which has been in position for more than 30 minutes shall not be

vibrated. (f) No-fines concrete shall be compacted using a minimum amount of punning.


(g) Vibrating equipment shall comply with BS 2769:Part 2 and the following:

(i) internal vibrators operating at a minimum of 10,000 cycles per minute; (ii) external vibrators operating at a minimum of 3,000 cycles per minute;

(iii) vibrating tables operating at a minimum of 5,000 oscillations per minute

may be used for precast elements subject to review without objection by the Project Manager; and

(iv) external clamp-on type, vibrators shall not be used.

20.7.14 Construction Joints

(a) The position and details of construction joints shall be arranged in such a manner that the possibility of cracking due to shrinkage is minimized. The Contractor shall submit a detailed method statement of its proposed pour strategy and substantiation of this strategy to the Project Manager for review without objection.

(b) Construction joints shall be normal to the axis or plane of the element being

constructed. (c) Waterstops shall be provided at construction joints in water retaining

structures, tunnels and at any other locations as shown on the Employer's Drawings.

(d) Laitance and loose material shall be removed from the surface of construction joints and the aggregate shall be exposed by a method reviewed without objection by the Project Manager. The work shall be carried out as soon as practicable after the concrete has hardened sufficiently for the cement matrix to be removed without disturbing the coarse aggregate. The surface of the construction joint shall be cleaned after the matrix has been removed.

(e) The surface of the construction joint shall be clean and dry before fresh

concrete is placed against it.

20.7.15 Curing Concrete

(a) Concrete shall be protected against harmful effects, including those due to weather, running water and drying out by one of the following methods:

(i) Method 1 : A liquid curing compound shall be applied to the concrete

surface by a low-pressure spray at the rate recommended by the manufacturer until a continuous visible covering is achieved;

(ii) Method 2 : The concrete surface shall be covered with hessian,

sacking, canvas or with a layer of fine aggregate at least 25 mm thick; the hessian, sacking, canvas or fine aggregate shall be kept constantly wet;

(iii) Method 3 : The concrete surface shall be covered with polyethylene

sheeting; concrete surfaces which have become dry shall be thoroughly wetted before the sheeting is placed; or


(iv) Method 4 : Unformed concrete surfaces shall be covered with polyethylene sheeting until the concrete has hardened sufficiently for water curing to be carried out. Water curing shall be carried out by spraying the concrete surface continuously with cool water or by ponding immediately after the sheeting is removed. If in the opinion of the Project Manager water curing is impracticable, Method 2 shall be used instead of water curing.

(b) Method 1 shall not be used on concrete surfaces against which concrete will

be placed or which will have a Class T1 finish or which will be painted or tiled.

(c) Methods 1, 2, 3 or 4 shall be used on unformed concrete surfaces immediately after the concrete has been compacted and finished. Methods 1, 2 or 3 shall be used on formed concrete surfaces immediately after the formwork has been removed.

(d) Polyethylene sheeting shall be impermeable and shall have a nominal thickness of 0.125 mm.

(e) Hessian, sacking, canvas and polyethylene sheeting shall be lapped and

securely held in position in such a manner that the concrete surface will not be damaged.

(f) Cold water shall not be applied to concrete surfaces or formwork.

(g) The different methods of protection shall be maintained for the minimum

periods stated in Table 20.8 after the concrete has been placed. The minimum periods may, subject to review without objection by the Project Manager, be reduced by the number of days during which formwork is left in position.

(h) When the ambient temperature exceeds 32°C full hot weather curing

techniques as described in ACI document ACI 305R-89, shall be implemented. Absorptive wood forms remaining in place shall not be considered a satisfactory means of curing in hot dry weather. Such forms shall be covered and kept moist.

Table 20.8: Minimum Periods of Protection for Concrete

Type of Structure Method of protection

Minimum period of protection (days)Concrete not

containing PFA or PPFAC

Concrete containing

PFA or PPFAC Water retaining structures, tunnels, and water tight structures

1 7 7

2, 3 or 4 7 9

Others 1 7 7 2, 3 or 4 4 5


20.7.16 Manufacture of Precast Concrete Units

(a) For all prestressed pretensioned members the length, cross section dimensions and straightness of precast concrete shall be measured at 28 ± 2 days after casting;

(b) Unless otherwise stated in the Contract the allowable dimensional variations

for precast concrete units shall not exceed those given in Table 20.9.

Table 20.9 Allowable Dimensional Variations

Length Variation Up to 3 m ± 6 mm 3 to 4.5 m ± 9 mm 4.5 to 6 m ± 12 mm Additional for every subsequent 6 m ± 6 mm Cross Section Variation (each direction) Up to 500 mm ± 6 mm 500 to 750 mm ± 9 mm Additional for every subsequent 250 m ± 3 mm Straightness or bow Deviation (deviation from intended line) Up to 3 m 6 mm 3 to 6 m 9 mm 6 to 12 m 12 mm Additional for every subsequent 6 m 6 mm

(c) Where the Project Manager requires tests to be carried out on members

manufactured off-Site, no members to which the tests relate shall be dispatched to Site until the tests have been completed and the results reviewed without objection by the Project Manager.

(d) All members shall be indelibly marked to show the description of the member

as shown on the Employer's Drawings, the production line on which they were manufactured, the date on which the concrete was cast and, if they are of symmetrical section, the face that will be uppermost when the member is in its correct position in the Permanent Works. The markings shall be so located that they are not exposed to view when the member is in its permanent position.

(e) Unless otherwise specified the vibrated top surface of precast concrete

members which will subsequently receive in-situ concrete shall be further prepared by the following methods:

(i) when the concrete is self-supporting but still sufficiently green the

concrete surface shall be sprayed with a fine spray of water or brushed with a stiff brush just sufficiently to remove the outer mortar skin and expose the larger aggregate without disturbing it; or

(ii) alternatively where this preparation proves impracticable the hardened

surface skin and laitance shall be removed by sand blasting or a needle gun.


(f) Hardened surfaces shall not be hacked.

(g) Retarding agents shall not be used.

(h) The joint surface shall be clean and damp but free of standing water immediately before any fresh concrete is placed against it.

20.7.17 Installation of Precast Concrete Units

(a) Contact surfaces between in-situ concrete and precast concrete units shall be prepared as stated in the Contract. Dimensional tolerances shall be checked before the precast concrete units are lifted into position.

(b) Temporary supports and connections shall be provided as soon as practicable

during installation of precast concrete units.

(c) Final structural connections shall be completed as soon as practicable after the precast concrete units have been installed.

(d) Levelling devices which have no load bearing function in the finished structure

shall be slackened, released or removed after the precast concrete units have been installed.

20.7.18 Loading of Concrete

(a) Loads which will induce a compressive stress in the concrete exceeding one-third of the compressive strength of the concrete at the time of loading or exceeding one-third of the grade strength, whichever is less, shall not be applied to concrete; allowance shall be made for the weight of the concrete in determining the loading. The strength of the concrete and the stresses produced by the loads shall be assessed by a method reviewed without objection by the Project Manager.

(b) Loads from materials not forming part of the Permanent Works or from

Contractor's Equipment or other vehicles, shall not be applied to no-fines concrete.

20.7.19 Storage of Materials for Joints

(a) Bitumen emulsion, joint sealant and primer for joint sealant shall be stored in sealed containers marked to identify the contents and protected from exposure to conditions which may affect the material. The materials shall be stored in accordance with the manufacturers' recommendations and shall not be used after the recommended shelf life has been exceeded.

(b) Joint filler, bond breaker tape and waterstops shall be stored in accordance

with the manufacturers' recommendations in a dry weatherproof store with a raised floor. Absorbent joint filler shall be stored in sealed plastic bags and shall not be exposed to moisture or air.


(c) Bearing strip for sliding joints supplied in rolls of 5 m length or less shall be unrolled immediately after delivery and shall be stored flat at full length on an even surface. Bearing strip supplied in rolls of more than 5 m length may be left in the original packing. Bearing strip shall be stored in accordance with the manufacturer's recommendations and shall be protected from mechanical damage and creasing; the two layers of strip shall be kept free from deleterious material.

20.7.20 Forming Joints

(a) Materials for joints shall be mixed and used in accordance with the manufacturers' recommendations.

(b) Joint filler shall be cut to size before fixing and shall be securely fixed in

position to the existing concrete surface before concreting. There shall be no gaps between the joint filler and formation.

(c) Waterstops shall be securely fixed in position to formwork in such a manner

that compaction of the concrete will not be affected. In-situ joints in waterstops shall be made using methods and equipment recommended by the manufacturer. Exposed waterstops shall be protected from exposure to conditions which may affect the waterstop and shall be kept free from rust, hydrocarbons and other deleterious material.

(d) Joints shall be formed in straight lines perpendicular to the surface of the

concrete unless otherwise stated in Contract.

(e) Saw-cut joints shall be formed where shown on the Employer's Drawings, in slab-on-ground areas. Joints shall be formed by use of a rotary-concrete saw to the depths shown on the Employer's Drawings.

20.7.21 Forming Grooves

(a) Grooves for joint sealant shall be straight and shall be perpendicular to the surface of the concrete. The bottom of the groove shall be flat and shall be parallel to the surface of the concrete.

(b) Grooves shall be formed by using timber or other formers reviewed without

objection by the Project Manager and shall not be formed by cutting back or raking out the joint filler. The grooves shall be located over the joint filler such that the upper surface of the joint filler is entirely contained in the groove.

20.7.22 Protection of Grooves

Before permanent sealing, grooves for joint sealant shall be protected from contamination by a temporary sealing strip or cover.

20.7.23 Sealing Joints

(a) The permanent sealing of joints shall be carried out at least 7 days after concreting.

(b) Immediately before permanent sealing, timber formers, temporary seals, dirt

and loose material shall be removed from the groove and the sides of the groove shall be cleaned and roughened by water jetting or sand blasting.


(c) Caulking material shall be firmly packed in the bottom of the groove if the joint sealant is not required to extend to the bottom of the groove.

(d) Bond breaker tape shall be fixed continuously and evenly along the bottom of

the groove for the full width and length of the groove. (e) Concrete surfaces within 75 mm of the edges of the joint shall be masked with

tape before the primer is applied and until the sealing of the joint is complete. (f) Primer for the joint sealant shall be applied to the sides of the groove in

accordance with the manufacturer's recommendations. (g) Joint sealant shall be applied between the minimum and maximum drying

times of the primer recommended by the manufacturer. The components of the sealant shall be thoroughly mixed in accordance with the manufacturer's recommendations using a power operated paddle mixer for sufficient time to produce a homogeneous mass without entrapped air. The sealant shall be dispensed into the groove as soon as practicable after mixing and within the time recommended by the manufacturer.

(h) The groove shall be clean and dry at the time of applying the primer and joint

sealant. (i) Excess joint sealant shall be removed by using a purpose made finishing tool

such that the finished surface of the sealant is between 4 mm and 6 mm below the face of the concrete.

20.7.24 Strip and Pad Bearing Installation

(a) The concrete surface shall be prepared with a mortar pad as specified on the Employer's Drawings. The mortar pad should be a minimum of 10 mm thick. The top surface of the mortar pad must not deviate by more than 3 mm in 1 m for strip bearings and no more than 2 mm across the mortar seating for pad bearings. The thickness of the mortar pad shall be such as to allow the bearing to be seated within the nominal 50 mm distance between concrete bearing faces, without intrusion into the upper concrete element concrete cover. The maximum thickness of mortar pad shall be 30 mm.

(b) The bearing shall be placed in position on the mortar pad and fixed in position

with epoxy adhesive of a type recommended by the bearing manufacturer and reviewed without objection by the Project Manager.

(c) The areas around the bearing must be blocked out with a void former to

ensure that concrete, when poured in the upper element cannot contact the lower concrete element.

20.7.25 Tolerances: Joints

(a) The line of straight joints shall be within 10 mm of the true line. (b) The line of curved joints shall be within 10 mm of the true curved line. (c) Joints shall be continuous across intersections of joints to within 5 mm of the

joint opposite. (d) The depth of grooves for joint sealant shall be within 3 mm of the specified

depth.


20.7.26 Drilled in bolts

The Contractor shall survey by cover meter, chipping of the concrete cover or trial drilling to the depth of the anchor bolt or bar anchorage to accurately identify the positions of the reinforcement in the vicinity of the required drill holes. Where holes clash with existing reinforcement, the Contractor shall submit this survey to the Project Manager for his review without objection four weeks prior to the commencement of fabrication of the base plates or other follow on work. The Contractor shall repair all redundant drill holes and chipped concrete with a non-shrink grout of equivalent strength to the concrete being investigated.

20.8 INSPECTION, TESTING & COMMISSIONING 20.8.1 Batch: Cement, PFA, Aaggregate, Admixture, Curing Compound

A batch of cement, PFA, aggregate, admixture or curing compound is any quantity of cement, PFA, aggregate, admixture or curing compound of the same type, manufactured or produced at the same time in the same place, covered by the same certificates and delivered to Site, or stored at the ready-mixed concrete plant, at any one time.

20.8.2 Samples: Cement, PFA, Aggregate, Admixture, Curing Compound, Water

(a) One sample of each type of cement, PFA, aggregate, admixture, curing compound and water shall be provided at the same time as particulars of the material are submitted to the Project Manager for review without objection.

(b) The size of each sample and the method of sampling shall be as stated in

Table 20.10. 20.8.3 Testing: Cement, PFA, Aggregate, Admixture, Curing Compound, Water

(a) Each sample of cement, PFA, aggregate, admixture, water and curing compound shall be tested to determine the properties stated in Table 20.11.

(b) The method of testing shall be as stated in Table 20.11. (c) The maximum total sulphate and chloride content of concrete shall be

determined on the basis of the results of tests for chloride content of each constituent.

20.8.4 Control of Alkali-aggregate Reaction in Concrete

(a) Measures to control the occurrence of alkali-aggregate reaction (AAR) in concrete shall be in accordance with Practice Note for Authorized Persons and Registered Structural Engineers No. 180 and submitted for review without objection by the Project Manager. Such control shall be achieved by limiting the reactive alkali content of the concrete as described in Clauses (b) - (d) unless in the opinion of the Project Manager the concrete element will not be subjected to moisture ingress throughout its design life.

(b) The reactive alkali content of concrete expressed as the equivalent sodium

oxide per cubic metre of concrete shall not exceed 3.0 kg.


(c) The equivalent sodium oxide (Na2O) content of concrete shall be calculated from the following expression:

Equivalent Na2O = A + B + C

(i) where A is the sum of the acid-soluble alkalis (expressed as equivalent

Na2O) of cement, admixtures and water; B is equal to 1/6 of the total alkalis of PFA (expressed as equivalent Na2O); and C is equal to 0.76 times the chloride ion (Cl) of the aggregate;

(ii) the acid-soluble alkali content of the cement shall be determined in

accordance with BS 4550:Part 2:1970 (excluding amendment AMD 7285, July 1992) and shall be taken as the average of the latest 25 daily determinations of equivalent sodium oxide plus twice the standard deviation of the results;

(iii) the acid-soluble alkali content of admixtures shall be determined in

accordance with BS 1881:Part 124:1988;

(iv) the acid-soluble alkali content of water shall be determined in accordance with APHA (17ed. 1989) Sections 3500-K and 3500Na;

(v) the total alkali content of the pulverised fuel-ash shall be determined in

accordance with BS 4550:Part 2:1970 (excluding amendment AMD 7285, July 1992) and shall be taken as the average of the latest 25 daily determinations of equivalent sodium oxide plus twice the standard deviation of the results; and

(vi) the equivalent sodium oxide content of the coarse and fine aggregates

shall be calculated from the quantity of chloride ion present which shall be measured in accordance with BS 812:Part 4:1976.

(d) The following particulars of the proposed concrete mix shall be submitted for

review without objection by the Project Manger:

(i) HOKLAS endorsed test certificates not older than 6 months giving the results of tests required in Clauses 20.8.4 (c) (ii)-(vi), with new HOKLAS test certificates submitted at quarterly intervals together with any necessary further calculations to demonstrate that the mix continues to comply with the limit on reactive alkali; and

(ii) calculations of the reactive alkali of the proposed mix.

Table 20.10: Size of Samples and Method of Sampling Cement, PFA,

Aggregate, Admixture, Curing Compound and Water

Material Size of sample Method of Cement 20 kg BS 4550:Part 1 PFA 20 kg BS 4550:Part 1 PPFAC 20 kg BS 4550 Coarse aggregate 25 kg BS 812:Part 102 Fine aggregate 10 kg BS 812:Part 102 Water 10 L BS 3148 Admixture (powdered) 1 kg BS 5075:Part 1 Admixture (liquid) 1 L BS 5075:Part 1 Curing compound 5 L BS 5075:Part 1


Table 20.11 : Methods of Testing Cement, PFA, Aggregate, Admixture, Curing Compound and Water

Material Property Method of testing OPC, RHPC, SRPC, PPFAC

Chemical composition BS 4550:Part 2 Fineness Compressive strength at 3, 7 and 28 days Initial and final setting times Soundness

BS 4550:Part 3

PPFAC Proportion by mass of PFA BS 6588

PFA Chemical composition BS 3892:Part 1 Fineness Moisture content

BS 3892:Part 1

Coarse aggregate, fine aggregate

Grading BS 812:Part 103 Silt content BS 812:Part 1 Chloride content BS 812:Part 117

Coarse aggregate

Flakiness index Ten percent fines Water absorption

BS 812:Part 105.1 PS 812:Part 111 BS 812:Part 2

Admixture Chloride content BS 5075 : Part 1 Curing compound Efficiency index Appendix 20A.1

Water

Initial setting times of cement compressive strength of test cubes

BS 3148

Organic content By inspection Inorganic impurities content APHA 209A Chloride content ASTM D512-81,

Method B Sulphide content ASTM D516-80,

Method A Alkaline carbonate and bicarbonate content

AOAC 1984, Text 33.076

pH value ASTM D1293-78 20.8.5 Batch: Concrete

A batch of concrete is any quantity of concrete produced in one cycle of operations of a batch mixer, or conveyed ready-mixed in a delivery vehicle, or discharged during one minute from a continuous mixer.

20.8.6 Reduction of Resting Frequency

The number of tests for workability or compressive strength of standard mix concrete may be reduced if after review without objection by the Project Manager it is confirmed that the standard of quality control is satisfactory.


20.8.7 Samples: Workability of Concrete

(a) One sample of concrete shall be provided from each batch of concrete to determine the workability of the concrete.

(b) The size of each sample and the method of sampling shall be in accordance

with CS1 except that if a superplasticising admixture is included in the concrete mix to produce flowing concrete, the sample shall be taken before the superplasticiser is added.

20.8.8 Testing: Workability of Concrete

(a) Each sample of concrete taken as stated in Section 20.8.7 shall be divided into two specimens; each specimen shall be tested to determine the workability of the concrete. The method of testing shall be the slump test in accordance with CS1.

(b) The average of the two slump values shall be calculated and referred to as

the average slump value. 20.8.9 Compliance Criteria: Workability of Concrete

(a) The average slump value of the two specimens taken from one sample of standard mix concrete shall be within the appropriate range stated in Table 20.1.

(b) The average slump value of the two specimens taken from one sample of

designed mix concrete shall be within 25 mm or 33% of the "Acceptable Slump Value", whichever is the greater.

20.8.10 Non-compliance: Workability of Concrete A batch of concrete shall be considered as not complying with the specified

requirements for workability if the result of any test for workability, carried out on a sample taken from the batch, does not comply with the specified requirements for workability.

20.8.11 Samples: Compressive Strength of Concrete

(a) For each concrete mix, one sample of concrete shall be provided from each amount of concrete as stated in Table 20.12 or from the amount of concrete produced each day, whichever is less. The sample shall be selected at random as follows:

(i) at the point of discharge from the mixer; or (ii) in the case of ready-mixed concrete, at the point of discharge from the

delivery vehicle; or

(iii) elsewhere as directed by the Project Manager; and

(iv) in no case to be from the first 0.3 m3 of concrete discharged from the truck.


(b) If the Contractor requests, or if the Project Manager directs, that the concrete be tested for compressive strength at ages other than 28 days, additional samples shall be provided. The number of additional samples shall be as stated in Section 20.8.11(a).

(c) The size of each sample and the method of sampling shall be in accordance

with CS1. If a superplasticising admixture is included in the concrete mix, the samples shall be taken after the superplasticiser is added and after the concrete is remixed.

Table 20.12: Rate Sampling of Concrete

Type of structure Amount of concrete

Masts Cantilevers 3 m or more in length Columns Shear walls Prestressed elements Other critical elements

10 m3 or 10 batches, whichever is less

Solid rafts Pile caps Mass concrete Retaining walls

100 m3 or 100 batches, whichever is less

Other types 25 m3 or 25 batches, whichever is less

20.8.12 Testing: Compressive Strength of Concrete

(a) Two 150 mm test cubes shall be made from each sample of concrete taken as stated in Section 20.8.11. Each pair of test cubes shall be tested to determine the compressive strength at 28 days.

(b) The method of making test cubes shall be in accordance with CS1. (c) The method of storing test cubes shall be in accordance with CS1. Test

cubes which are cured on Site shall be delivered to the HOKLAS accredited testing laboratory at least 48 hours before the tests are due to be carried out.

(d) The method of testing shall be in accordance with CS1. (e) For the purpose of assessing compliance of designed mix concrete as stated

in Sections 20.8.14 and 20.8.15, the average of the two compressive strengths of the pair of test cubes shall be calculated and referred to as the test result.

20.8.13 Non-compliance : Compressive Strength of Standard Mix Concrete

If the result of any test for compressive strength at 28 days of standard mix concrete is less than the grade strength, the Project Manager may direct that tests as stated in Sections 20.8.16 to 20.8.19 be carried out on concrete cores or on samples taken from the hardened concrete.


20.8.14 Compliance Criteria : Compressive Strength of Designed Mix Concrete

The results of tests for compressive strength at 28 days of designed mix concrete shall comply with Clause 59 of the Building (Construction) Regulations of Hong Kong.

20.8.15 Non-compliance : Compressive Strength of Designed Mix Concrete

If designed mix concrete is considered as not complying with the specified requirements for compressive strength as stipulated in Clause 59 of the Building (Construction) Regulations of Hong Kong, the Project Manager may direct that tests as stated in Sections 20.8.16 to 20.8.19 are carried out on concrete cores or on samples taken from the hardened concrete.

20.8.16 Samples: Hardened Concrete and Concrete Cores

(a) The number of samples, including cores, of hardened concrete to be provided for testing shall be as stated in the Contract or, if testing is to be carried out as a result of the concrete not complying with the Specification, shall be as directed by the Project Manager and to the satisfaction of the Buildings Department. In the event testing is directed as a result of concrete not complying with the Specification, all the concrete being investigated shall be divided as directed by the Project Manager into separate test locations. The number of samples taken from each location shall be as directed by the Project Manager and the quality of concrete at each location shall be assessed separately. The positions from which the samples are taken shall be as directed by the Project Manager.

(b) The size of samples and the method of sampling shall be in accordance with

CS1. (c) Cores shall be set out to avoid cutting steel reinforcement. .

(d) After coring, all coring locations shall be made good with non-shrink cementitious grout with the same minimum compressive strength as at the core location.

20.8.17 Testing: Concrete Cores

(a) Each concrete core shall be inspected for evidence of segregation of the constituents and for the presence of voids. Specimens selected from each core shall be tested to determine the compressive strength.

(b) The method of preparing and inspecting concrete cores and of testing the

cores to determine the compressive strength shall be in accordance with CS1. Concrete cores shall not be tested for compressive strength until the concrete has reached an age of 28 days.

20.8.18 Compliance Criteria: Concrete Cores

(a) Concrete cores shall not show evidence of segregation. The extent of voids in the core shall not be more than 'few' in accordance with Table 4 of CS1 and there shall be no honeycombing.


(b) The results of tests for compressive strength of concrete cores shall be interpreted in accordance with BS 6089. Adjustments to the measured strength in respect of the age of the core when tested shall not be made. The estimated equivalent cube strength of each core specimen shall be calculated in accordance with CS1. Subject to the approval of the Buildings Department, for any set of cores representing a test location, the average estimated equivalent cube strength shall be at least 85% of the specified grade strength, and each individual estimated equivalent cube strength shall be at least 75% of the specified grade strength.

20.8.19 Analysis of Hardened Concrete

(a) Each sample of hardened concrete shall be tested to determine the properties or the composition of the concrete as stated in the Contract or, if testing is to be carried out as a result of the concrete not complying with the specified requirements, shall be tested as directed by the Project Manager.

(b) Tests on hardened concrete shall be carried out within 14 days of the Project

Manager's request for the test.

(c) The method of testing shall be in accordance with CS1.

(d) When directed by the Project Manager, in-situ rebound hammer tests to determine the strength of hardened concrete shall be undertaken in accordance with BS EN 12504-2:2001.

20.8.20 Batch: Precast Units

A batch of precast units is any quantity of precast units, including prestressed units, of the same type and size, of the same concrete mix, manufactured in the same place, covered by the same certificates and delivered to Site at any one time.

20.8.21 Samples: Precast Units

The number of precast units to be provided for testing from each batch shall be as stated in the Contract.

20.8.22 Testing: Precast Units

(a) Load tests shall be carried out to determine the deflection and recovery of each precast unit, including prestressed units, provided for testing and to determine the resistance to cracking of each prestressed unit provided for testing.

(b) Load tests shall be carried out in accordance with a procedure submitted to

and reviewed without objection by the Project Manager. The age at which the units are to be tested, the test load, the points at which the loads are to be applied and the points at which the unit is to be supported shall be as stated in the Contract or as proposed by the Contractor and reviewed without objection by the Project Manager.

(c) The method of testing shall be as stated in Appendix A20.2. (d) Post-tensioned units shall not be tested until at least 7 days after the ducts

have been grouted.


20.8.23 Compliance Criteria: Precast Units

The results of load tests on precast units shall comply with the requirements stated in the Contract.

20.8.24 Batch: Joint Filler, Joint Sealant, Waterstops

A batch of joint filler, joint sealant or waterstop is any quantity of joint filler, joint sealant or waterstop of the same type, manufactured by the same manufacturer, covered by the same certificates and delivered to Site at any one time.

20.8.25 Samples: joint filler, joint sealant, waterstops

(a) One sample of each type of joint filler, joint sealant or waterstop shall be provided at the same time as particulars of the material are submitted to the Project Manager for review without objection. One sample of each type of material shall be provided from each batch of the material delivered to Site. One sample of mixed joint sealant shall be provided on each day that joints are sealed.

(b) The size of each sample of joint filler shall be sufficient to permit all tests

stated in Appendix A20.3 to be carried out. (c) Samples of unmixed joint sealant and primers for joint sealant shall be taken

from sealed containers delivered to Site. Samples of mixed joint sealant shall be taken immediately before the sealant is applied to the joint. The method of sampling shall be as stated in BS 2499, Appendix A. The size of each sample shall be as follows:

(i) unmixed joint sealant : 1 kg; (ii) mixed joint sealant : 1.5 kg; and

(iii) primer for joint sealant : 1 L.

(d) The size of each sample of waterstop shall be 1 m.

20.8.26 Testing: Joint Filler, Joint Sealant, Waterstops

(a) Samples of joint filler shall be tested to determine the disintegration and shrinkage, the recovery value and reduction in mass and the extrusion. The method of testing shall be in accordance with Appendix A20.3.

(b) Samples of joint sealant shall be tested to determine the properties stated in

Table 20.13. The method of testing shall be as stated in Table 20.13. (c) Samples of waterstop shall be tested to determine the properties stated in

Table 20.14. The method of testing shall be as stated in Table 20.14.


Table 20.13: Testing Joint Sealant

Type of joint sealant Properties to be tested Method of testing Polysulphide-based sealant Polyurethane-based sealant

Rheological properties Plastic deformation Adhesion and tensile modulus Application life Adhesion in peel Loss of mass after heat ageing Staining

BS 4254

Hot-applied bitumen rubber sealant

Extension Flow Penetration Degradation

BS 2499

Table 20.14 : Testing Waterstops

Property Method of testing

Rubber waterstops PVC waterstops

Density BS 903:Part A1 BS 2782:Part 6, Methods 620A to 620D

Hardness BS 903:Part A26 BS 2782:Part 3, Method 365D

Tensile strength BS 903:Part A2 and BS 903:Part A5

BS 2782:Part 3, Methods 320A to 320F

Elongation at break point

BS 903:Part A2 and BS 903:Part A5

BS 2782:Part 3, Methods 320A to 320F

Water absorption BS 903:Part A18 BS 2782:Part 4, Methods 430A to 430D

Softness number - BS 2782:Part 3, Method 365A

20.8.27 Compliance Criteria: Joint Filler

(a) The results of tests on joint filler shall comply with the following requirements:

(i) none of the three specimens in the weathering test shall show any sign of disintegration or shrinkage;

(ii) each of the four specimens in the compression and recovery test shall

have a recovery value of at least 70%, and the reduction in mass of each of the two new specimens shall not exceed 1%; and

(iii) the extrusion of the free edge of the specimen shall not exceed 6 mm as

determined by the extrusion test.


APPENDIX A20.1

DETERMINATION OF THE EFFICIENCY INDEX OF CURING COMPOUNDS

A20.1.1 Scope This method covers the determination of the efficiency index of membrane forming

curing compounds for concrete. A20.1.2 Materials (a) The following materials are required:

(i) Ordinary Portland cement complying with BS 12, specially selected for testing admixtures and identified as 'CAA/BS 5075:Part 1 Reference Portland Cement'; the cement shall be stored in an airtight container;

(ii) oven-dry natural sand with a rounded particle shape complying with

BS 882 and with the grading stated in Table A20.1.1; and (iii) petroleum jelly, mineral oil or a proprietary release agent.

Table A20.1.1 : Grading of Sand

BS test sieve Percentage by mass passing

1.18 mm 100

600 μm 90 - 100 300 μm 12 - 40 150 μm 0 - 6

A20.1.3 Apparatus

(a) The following apparatus is required:

(i) moulds constructed of corrosion resistant metal. The moulds shall be watertight, tapered and constructed so as to prevent distortion and shall have the following dimensions:

− internal size (top): 150 mm (0 mm to +5 mm) x 300 mm (0 mm

to +5 mm); − internal size (bottom): 145 mm (0 mm to +5 mm) x 295 mm (0 mm

to +5 mm); − internal depth: 50 mm ± 2 mm; − side and end slope: 5% ± 1%; and − top flange width: at least 12 mm;

(ii) a balance readable and accurate to 0.1 g;


(iii) a cabinet complying with BS 2648 capable of storing specimens at a temperature of 38°C ± 1°C and at a relative humidity of 35% ± 5%. The cabinet shall have three perforated or mesh shelves each capable of supporting two specimens during the test so as to ensure a clear space of at least 40 mm on all sides of individual specimens. The cabinet shall be equipped to circulate air over the specimens at an approximate rate of 0.5 m/s;

(iv) spray equipment, such as the Wagner model W320 electric spray gun,

designed to permit the curing compound to be aspirated and applied evenly to the specimen;

(v) an electrically driven mixer complying with Clause 8.3 of BS 4551 and

having a nominal capacity of 12 kg; (vi) a vibrating table or a vibrating hammer with a 40 mm square foot or a

compacting bar made of non-absorbent material, approximately 200 mm long and with a 40 mm square foot;

(vii) a metal screed, 148 mm long, of L-shaped section 50 mm x 25 mm with

the shorter side having a sharpened leading edge. The screed shall be supported across the top of the mould by a 200 mm long rigid member which can slide on the flanges of the mould while holding the screed horizontal. The height of the screed shall be adjustable to give a uniformly flat surface finish to the mortar 7 mm ± 1 mm below the top of the mould;

(viii) a metal tray with sides at least 3 mm high and an area equal to the

surface area of the specimen; (ix) a hydrometer complying with BS 718; (x) a float, 250 mm x 140 mm ± 5 mm; and (xi) a medium soft 50 mm paint brush.

A20.1.4 Procedure: Preparation of Specimens

(a) The procedure for preparation of the specimens shall be as follows:

(i) three pairs of specimens shall be prepared, each pair comprising one test specimen and one control specimen;

(ii) mixing shall be carried out in a room having a temperature of 27°C ± 3°

C. The materials shall be brought to room temperature before mixing. A mortar mix shall be prepared comprising one part by mass of cement, three parts by mass of sand and 0.44 parts by mass of water;

(iii) the sand and cement shall be placed in the mixer and mixed for

1 minute. The water shall be added and mixing continued for a further 4 minutes;

(iv) the two moulds shall be cleaned, lightly coated with the petroleum jelly,

mineral oil or release agent and weighed to the nearest 0.1 g (m1);


(v) the specimens shall be prepared 20 minutes after completion of mixing and shall be cast in pairs;

(vi) a layer of mortar approximately 25 mm deep shall be placed in each

mould and tamped 50 times with the compacting bar. A second layer of mortar, sufficient to overfill the moulds slightly, shall be placed in each mould and tamped 50 times with the compacting bar. Indentations formed by tamping shall be filled and the surface shall be levelled by vigorous compaction by manual methods. Alternatively, each layer shall be compacted by using the vibrating table or vibrating hammer and levelled using the float;

(vii) a uniform surface, free from undulations and surface defects, shall be

produced using the minimum number of passes of the metal screed working along the length of the mould in both directions. The finished surface shall be 7 mm ± 1 mm below the top of the mould;

(viii) the surface shall be brushed lightly with the paint brush to give an even

texture; and (ix) The moulds and specimens shall each be weighed to the nearest

0.1 g (m2) immediately before the curing compound is applied. A20.1.5 Procedure: Determination of Efficiency Index (a) The procedure for determination of the efficiency index shall be as follows:

(i) a sample of the curing compound shall be taken by the method for sampling admixtures in accordance with BS 5075:Part 1, Appendix A;

(ii) the sample shall be agitated thoroughly and the relative density

determined at room temperature with the hydrometer. The mass required to give the coverage rate stated in Section A20.1.5(c) shall be calculated from the relative density. The mass of the curing compound applied shall be within ± 0.5 g of that required to give the specified coverage rate;

(iii) the curing compound shall be applied at the coverage rate

recommended by the manufacturer, or at a rate of 0.2 L/m² ± 0.01 L/m² if no rate is recommended;

(iv) the curing compound shall be applied to the test specimen one hour

after the specimen has been prepared, using the spray equipment or in accordance with the manufacturer's recommendations. The curing compound shall be shaken well before and during application. The spray gun shall be held so that the nozzle is as near vertical as possible and at a height which will result in uniform application and minimum overspray. The specimen shall be coated uniformly by applying several layers over the whole surface until the specified coverage is reached, checked by repeated weighing. Over spray shall be wiped from the exposed faces and edges of the mould. The whole application procedure shall be completed in not more than 2 minutes;


(v) the test specimen and the control specimen shall each be weighed to the nearest gram (m3) and placed immediately on the lowest shelf of the cabinet. After the second pair of specimens has been prepared and weighed, the first pair shall be moved up one shelf and the second pair placed on the lowest shelf. After the third pair of specimens has been prepared and weighed, the first two pairs shall be moved up one shelf and the third pair placed on the lowest shelf;

(vi) the total time for making the specimens, coating the test specimen and

placing the pair in the cabinet shall not exceed 2 hours; (vii) the specimens shall be kept in the cabinet for 72 hours ± 15 minutes

after application of the curing compound. Each specimen shall be weighed to the nearest 0.1 g at 24 hours ± 15 minutes and 48 hours ± 15 minutes. Each specimen shall be weighed to the nearest 0.1 g (m4 and m5) at 72 hours ± 15 minutes; and

(viii) the metal tray shall be weighed to the nearest 0.1 g (m6) and coated

with the same quantity ± 0.5 g of curing compound used on the test specimen. The coated tray shall be weighed to the nearest 0.1 g (m7) and placed in the cabinet for 72 hours ± 15 minutes after application of the curing compound. The tray shall be removed from the cabinet and weighed to the nearest 0.1 g (m8).

A20.1.6 Calculation

(a) The proportion of solvent lost (V) by the curing compound during the test period shall be calculated from the equation:

(m7 - m8)

V = ________ (m7 - m6) where:

− m6 is the mass of the tray measure in grams; − m7 is the mass of the tray after coating measured in grams; and − m8 is the mass of the tray after 72 hours in the cabinet measured in grams.


(b) The loss of water from the test specimen (Wt) and the loss of water from the control specimen (Wc) shall be calculated for each pair of specimens from the following equations:

(m3 - m4) - V(m3 - m2)

Wt = ___________________ x 100% (m2 - m1) (m2 - m5)

Wc = _______ x 100% (m2 - m1) where:

- m1 is the mass of the mould measured in grams; - m2 is the mass of the mould and test or control specimen as appropriate

measured in grams; - m3 is the mass of the mould and test specimen after coating measured in

grams; - m4 is the mass of the mould and test specimen after 72 hours in the cabinet

measured in grams; and - m5 is the mass of the mould and control specimen after 72 hours in the

cabinet measured in grams.

(c) The efficiency index (Et) of the curing compound shall be calculated for each test specimen from the equation:

(Wc - Wt)

Et = ________ x 100% Wc

The efficiency index (E) of the curing compound shall be calculated as the average of Et for the three test specimens.

A20.1.7 Reporting of Results (a) The following shall be reported:

(i) details of the sample of curing compound including identification, source, size, date received and age at test;

(ii) method of compacting the mortar;

(iii) method of applying the curing compound and the type of spray gun

used;

(iv) rate of application of the curing compound to the nearest 0.01 L/m²;

(v) duration of the test; and

(vi) efficiency index of the curing compound to the nearest 0.1%.


APPENDIX A20.2

DETERMINATION OF THE DEFLECTION, RECOVERY AND RESISTANCE TO CRACKING OF PRECAST UNITS

A20.2.1 Scope This method covers the determination of the deflection and recovery of precast

units, including prestressed units, and the resistance to cracking of prestressed units by means of a load test.

A20.2.2 Equipment (a) The following equipment is required:

(i) rigid supports;

(ii) test loads;

(iii) equipment for measuring the loads applied, readable and accurate to 2% of the specified test load; and

(iv) equipment for measuring the deflection and recovery, readable and

accurate to 0.5 mm. A20.2.3 Procedure (a) The procedure shall be as follows:

(i) precast unit shall be supported at the specified points of support;

(ii) upward deflection at mid-span due to the prestressing force in a prestressed unit and the deflection at mid-span due to the self-weight of a non-prestressed unit shall be measured;

(iii) specified test load shall be applied at the specified loading points in not

less than ten approximately equal increments;

(iv) specified test load shall be maintained for 5 minutes and removed in not less than five approximately equal decrements;

(v) deflection at mid-span shall be measured for each load increment and

each load decrement and 5 minutes after the loads have been removed;

(vi) steps (iii) to (v) shall be repeated; and

(vii) load-deflection graphs shall be plotted.



(a) The following shall be reported:

(i) details of the precast unit, including place of manufacture;

(ii) the age of the concrete in the precast unit at the time of the test;

(iii) loads applied to the nearest 2% of the specified test load;

(iv) deflections measured to the nearest 0.5 mm;

(v) load-deflection graphs; and

(vi) details of any cracks.


APPENDIX A20.3

DETERMINATION OF THE DISINTEGRATION AND SHRINKAGE, THE RECOVERY VALUE AND

REDUCTION IN MASS, AND THE EXTRUSION OF JOINT FILLER A20.3.1 Scope This method covers the determination of the disintegration and shrinkage of joint

filler, by weathering test, the recovery value and reduction in mass of joint filler by the compression and recovery test, and the extrusion of joint filler by the extrusion test.

A20.3.2 Apparatus (a) The following apparatus is required:

(i) equipment for measuring the size of the joint filler, readable and accurate to 0.5mm;

(ii) ventilated drying oven;

(iii) water bath;

(iv) watertight weathering test pan with a ribbed bottom and a fitted slotted

lid designed to hold 3 specimens of joint filler vertically on edge; (v) refrigerator; (vi) equipment for measuring the thickness of the joint filler readable and

accurate to 25 μm; (vii) balance readable and accurate to 0.01 g; (viii) compression test machine complying with BS 1610 : 1985 with

auxiliary platens 100 mm x 100 mm and a minimum thickness of 13 mm; and

(ix) extrusion mould open on one side only and rigidly fixed to a base

plate. The mould shall be 100 mm x 100 mm (+ 0.5 mm, - 0 mm) internally and shall be of sufficient depth to test the specimen. The mould shall be provided with a close fitting pressure plate which shall fit without binding and with a horizontal measuring dial gauge or device readable and accurate to 25 μm.

A20.3.3 Procedure : Weathering Test (a) The procedure for determination of the disintegration and shrinkage by the

weathering test shall be as follows:

(i) 3 specimens from the sample shall be prepared, each 115 mm x 115 mm (± 2.5 mm);


(ii) specimens shall be placed in the oven and maintained at a temperature of 55°C, ± 5°C for 7 days. The specimens shall be removed from the oven and immediately immersed in water at room temperature for 24 hours;

(iii) specimens shall be placed in the test pan and the pan shall be filled

with water to half the depth of the specimens;

(iv) specimens shall be subjected to 5 cycles of freezing and thawing as follows:

- test pan and specimens shall be placed in a refrigerator and the

water frozen to minus 7°C or below for a period of at least 4 hours after initial freezing; and

- test pan shall be removed from the refrigerator and placed in the bath without disturbing the specimens for a period of one hour after thawing of the water in the test pan is complete. The water in the bath shall be maintained at a temperature of between 18°C and 38°C;

(v) after the fifth cycle, the specimens shall be removed from the test pan

and air dried at room temperature for 48 hours; and

(vi) specimens shall be inspected for evidence of disintegration or shrinkage.

A20.3.4 Procedure: Compression and Recovery Test

(a) The procedure for determination of the recovery value and reduction in mass by the compression and recovery test shall be as follows:

(i) four specimens from the sample shall be prepared, each

100 mm x 100 mm (± 2.5 mm); (ii) thickness (t1) of the four specimens shall be measured to the nearest

0.1 mm, and two specimens shall be weighed to within 0.1% of their mass (m1);

(iii) each specimen shall be subjected to three applications of load in the

compression test machine at 24 hour intervals. During each application of load the specimen shall be compressed to 50% of its original thickness at a rate of strain of 1.3 mm per minute. The load required to achieve the compression shall be at least 0.07 N/mm² and shall not exceed 10 N/mm². The load shall be released immediately the specified amount of compression is reached;

(iv) after the third application of load, a recovery period of 30 minutes shall

be allowed and the thickness (t2) of each specimen shall be measured to the nearest 0.1 mm; and

(v) two previously weighed specimens shall be re-weighed to within 0.1%

of their mass (m2).


A20.3.5 Procedure: Extrusion Test

(a) The procedure for determination of the extrusion by the extrusion test shall be as follows:

(i) one 100 mm x 100 mm (± 0.5 mm) specimen shall be prepared;

(ii) thickness of the specimen shall be measured to the nearest 0.1 mm;

and

(iii) specimen shall be placed in the extrusion mould and subjected to one application of load as stated in Section A20.3.4(c). The extrusion at the open side of the mould shall be measured to the nearest 0.1 mm with the gauge or device when the specimen is compressed to 50% of the original thickness and before the load is released.

A20.3.6 Calculation

(a) The recovery value (R) of each specimen shall be calculated from the equation:

R = t 2/t1 x 100 % where:

- t1 is the original thickness of the specimen (mm) - t2 is the thickness of the specimen after the third application of load (mm)

(b) The reduction in mass (M) of each specimen shall be calculated from the

equation: M = (m1 - m2)/m1 x 100 % where:

- m1 is the original mass of the specimen (g) - m2 is the mass of the specimen after the third application of load (g)



(i) type and source of filler; (ii) any evidence of disintegration or shrinkage as a result of the

weathering test; (iii) recovery values to the nearest 0.5%; (iv) reductions in mass to the nearest 0.1%; and (v) extrusion to the nearest 0.1 mm.


APPENDIX A20.4

ROUTINE CHECKS FOR PLANT AND EQUIPMENT

PART 1 BATCHING AND MIXING EQUIPMENT A20.4.1 Daily Routine Adjust tare weights and clean weighing dials. Ensure weighing hoppers empty properly. Wash-out central mixer drum or pan. A20.4.2 Weekly Routine Maintain all hoppers and doors in clean and efficient working order. Remove any cement or concrete build-up in mixer. Shake out cement silo filler sock and maintain in efficient working order. Clean knife edges on weighing equipment. Check calibration of moisture meter. A20.4.3 Monthly Routine Check calibration of all weigh scales. Check calibration of water meter. Check calibration of admixture dispenser. A20.4.4 Quarterly Routine Inspection and testing of all weigh scales over their complete range. PART 2 TRANSPORTING EQUIPMENT - MIXER AND AGITATOR UNITS A20.4.5 Daily Routine Wash out truck mixer drum. A20.4.6 Monthly Routine Check operation of revolution counters. Check calibration of mixer truck water meter.

General Materials & Workmanship Specification 1/17 January 2011 Issue No. 5, Volume 1 – Civil & Structural Works Section 21 - Prestressing

SECTION 21 PRESTRESSING 21.1 GENERAL 21.1.1 Materials for Grout

Materials for grout for prestressing systems shall comply with Section 20 except as stated in this Section.

21.2 DEFINITIONS AND ABBREVIATIONS 21.2.1 Duct

Duct is a void formed in the concrete to accommodate a prestressing tendon. 21.2.2 Prestressing Components

Prestressing components are the components used in a prestressing system, including anchorages, grips, tendon deflectors, couplers, wedges, swages, nuts and other devices used to grip the prestressing tendon.

21.2.3 Prestressing Tendon

(a) Prestressing tendon is:

(i) an individual steel wire, wire strand or alloy steel bar in a duct, or

(ii) an individual steel wire, wire strand or alloy steel bar not in a duct, or

(iii) a group of steel wires or wire strands in a duct used in a prestressing system.

21.2.4 Sheath

Sheath is a tube or lining which is used to form a duct and which is left in place. 21.3 MATERIALS 21.3.1 Prestressing Tendons

(a) Prestressing tendons shall comply with the following: High tensile steel wire and strand for the prestressing of concrete : BS 5896 Hot rolled and processed high tensile alloy steel bars for the prestressing of concrete : BS 4486.

(b) Steel wire and wire strand shall be in coils of sufficiently large diameter to allow the steel wire and wire strand to pay off straight, without any permanent set or bends.

(c) Alloy steel bars shall be straight.


21.3.2 Prestressing Components

(a) Prestressing components shall be a proprietary type reviewed without objection by the Project Manager.

(b) Prestressing anchorages shall comply with BS 4447 and shall allow a

minimum of 25 mm cover to cropped ends of prestressing tendons. 21.3.3 Sheaths

(a) Sheaths shall be a proprietary type reviewed without objection by the Project Manager and shall be steel or other material reviewed without objection by the Project Manager. Sheaths shall be rigid and strong enough to retain their shape during fixing and concreting and to withstand forces from the prestressing tendons without damage.

(b) The design of ducts shall allow for grout to be injected from either end. There

shall be no sudden changes in the diameter of the duct. 21.3.4 Grout Vents and Taps

Taps for grout vents in ducts shall be a proprietary type reviewed without objection by the Project Manager and shall allow closure of the vents without loss of pressure in the duct. Vents to be used as grout entry points shall be threaded or fitted with screw connectors or other similar devices for connection to grout pumps.

21.3.5 Grout for Prestressing Systems

(a) Grout for prestressing systems shall consist of ordinary Portland cement and water. Sand, PFA and admixtures shall not be used unless otherwise specified in the Contract, or reviewed without objection by the Project Manager.

(b) Grout shall have a minimum crushing strength of 25 MPa at 7 days. (c) The amount of bleeding of grout shall not exceed 2% in the first 3 hours and

shall not exceed 4% in total; the water shall be reabsorbed by the grout during the 24 hours after mixing.

(d) Free expansion of grout shall not exceed 10% at the ambient temperature. (e) The maximum total chloride content of grout, expressed as a percentage

relationship between the chloride ion and the cementitious content by mass in the grout, shall not exceed 0.1%.

(f) Admixtures for grout shall not contain chlorides.

(g) Grout shall have a water cement ratio as low as possible consistent with the

necessary workability and under no circumstances shall the water cement ratio exceed 0.45.

21.3.6 Handling of Prestressing Tendons

Prestressing tendons shall not be subjected to rough handling, shock loading or dropping from a height.


21.3.7 Handling of Prestressing Components

Prestressing components shall be handled in accordance with the manufacturers' recommendations.

21.3.8 Storage of Materials for Prestressing Systems

(a) Each prestressing tendon shall be tagged with a number to identify the coil or bundle number of the prestressing tendon used.

(b) Prestressing tendons and sheaths shall be stored off the ground on level

supports and in a manner which will not result in damage or deformation to the materials or in contamination of the materials.

(c) Different types and sizes of prestressing tendons, prestressing components

and sheaths shall be stored separately. (d) Prestressing tendons, prestressing components and sheaths shall not be

stored on or adjacent to concrete surfaces which form part of the Permanent Works.

(e) Prestressing tendons, prestressing components and sheaths shall be

protected from exposure to conditions which may affect the material. 21.3.9 Surface Condition of Materials for Prestressing Systems

(a) Prestressing tendons, prestressing components and sheaths shall be clean at the time of installation and shall be free from loose mill scale, loose rust, pitting, grease or any substance which in the opinion of the Project Manager is likely to reduce the bond or affect the prestressing tendons, prestressing components, sheaths, concrete or grout chemically. The prestressing tendons, prestressing components and sheaths shall be maintained in this condition until concrete or grout is placed around them.

(b) If the surface condition of the prestressing tendons, prestressing components

or sheaths deteriorates such that it does not comply with the requirements stated in Clause 21.3.9(a), the prestressing tendons, prestressing components or sheaths shall be cleaned or dealt with by other methods reviewed without objection by the Project Manager.

21.4 SUBMISSIONS 21.4.1 Particulars of Prestressing Systems

(a) The following particulars of the proposed prestressing systems shall be submitted to the Project Manager for review:

(i) details of the prestressing system, including prestressing tendons,

prestressing components, sheaths and tensioning apparatus;

(ii) sequence of prestressing and ends of prestressing tendons from which prestress will be applied ;


(iii) calculated values of: • each type of loss of prestress; • prestressing tendon forces; and • extensions of prestressing tendons and details of the method of

measuring the extensions;

(iv) a certificate showing that the tensioning apparatus has been tested and calibrated by an agent reviewed without objection by the Project Manager within a period of two years before the apparatus is to be used;

(v) any alterations to the reinforcement or additional reinforcement required

to allow for primary bursting effects;

(vi) details of corrosion protection required for the prestressing system; and

(vii) details of the format of tensioning schedules and of reports of tensioning operations, grouting operations and testing of duct friction.

(b) Calculations for loss of prestress due to creep shall be based on the

information stated in the Contract. 21.4.2 Particulars of Prestressing Tendons

(a) The following particulars of the proposed prestressing tendons shall be submitted to the Project Manager for review without objection:

(i) a certificate from the manufacturer showing the manufacturer's name,

the date and place of manufacture and showing that the prestressing tendons comply with the requirements stated in the Contract and including details of: • cast analysis; • diameter, cross-sectional area and unit mass; • results of tests for mechanical properties, including the characteristic

breaking load, characteristic 0.1% proof load, elongation at maximum load, relaxation and modulus of elasticity; and

• results of tests for ductility of prestressing wires. 21.4.3 Particulars of Grout Mix and Grouting Procedure

(a) The following particulars of the proposed grout mix and grouting procedure for prestressing systems shall be submitted to the Project Manager for review without objection:

(i) water:cement ratio by mass;

(ii) details of mixing and grouting equipment;

(iii) method of quality control during grout injection; and

(iv) details of grouting trials.



(a) Representative samples of the following items shall be submitted to the Project Manager at the same time as particulars of the prestressing systems are submitted:

(i) prestressing tendons; (ii) prestressing components;

(iii) sheaths; and

(iv) grout vents and taps.

21.5 WORKMANSHIP 21.5.1 Installation of Prestressing Systems

(a) Prestressing operations shall be carried out with due regard to the energy stored in a stressed tendon.

(b) Prestressing tendons, prestressing components and sheaths shall be

accurately located and maintained in the correct position during all operations; supports shall be placed at a maximum spacing of 600 mm.

21.5.2 Installation of Prestressing Tendons

(a) Prestressing tendons from each batch shall not be installed until testing of the batch has been completed.

(b) Steel wires, wire strands and alloy steel bars which will be tensioned in one operation shall be taken from the same batch.

(c) Individual steel wires and wire strands in the same duct shall not be twisted

together. Strands which have become unravelled shall not be used. (d) Alloy steel bars which have become bent shall not be straightened. Small

adjustments for straightness may be made provided the straightening is carried out at the ambient temperature by non-mechanical methods and provided that no force is applied on the threaded portion. Bars which have become bent in the threaded portion shall not be used.

(e) After manufacture, prestressing tendons shall not be welded and heat

treatment, work-hardening, galvanizing and other metallic coatings shall not be applied. Prestressing tendons which have been damaged mechanically or by work-hardening or heating shall not be used.

21.5.3 Cutting Prestressing Tendons

Prestressing tendons shall be cut using either a high speed abrasive cutting wheel or a friction saw. Flame cutting shall not be used.


21.5.4 Joints in Prestressing Tendons

Joints in prestressing tendons shall be made using proprietary couplers fixed in accordance with the manufacturer's recommendations.

21.5.5 Use of Prestressing Components

Prestressing components shall be used in accordance with the manufacturers' recommendations.

21.5.6 Installation of Sheaths

At the time of tensioning, sheaths shall be free from dents or other irregularities which may affect tensioning.

21.5.7 Joints in Sheaths

(a) Joints in sheaths shall be securely taped to prevent penetration of the duct by concrete or grout. Joints in adjacent sheaths shall be staggered by at least 300 mm.

(b) Where sheaths are used, the number of joints shall be kept to a practicable

minimum and sleeve connectors shall be used for jointing. 21.5.8 Installation of Grout Vents and Taps

(a) Grout vents and taps shall be provided at the following positions:

(i) all crests of the prestressing tendon profile;

(ii) all low points of the prestressing tendon profile;

(iii) all anchorages; and

(iv) intervals not exceeding 15 m.

(b) Vents shall not be placed at positions where they will be blocked by the prestressing tendons after tensioning.

21.5.9 Tensioning of Prestressing Tendons

(a) Apparatus for tensioning prestressing tendons shall impose a controlled total force gradually and shall not induce excessive secondary stresses in the prestressing tendons, prestressing components, structure or element to which prestress is being applied.

(b) Prestressing tendons shall be securely attached to jacks and tensioning

apparatus. (c) Steel wires or wire strands which are tensioned simultaneously shall be

approximately the same length between anchorage points. (d) The force in the prestressing tendons during tensioning shall be measured by

direct reading load cells or obtained indirectly from pressure gauges fitted in the hydraulic system. Load measuring devices shall be accurate to within 2%.


(e) The extension of prestressing tendons and any movement of prestressing tendons in the gripping devices shall be measured during tensioning. The elongation of prestressing tendons shall be measured to an accuracy of 2% or 2 mm, whichever is the more accurate.

(f) Tensioning apparatus and load measuring devices shall be calibrated before

tensioning starts and at regular intervals reviewed without objection by the Project Manager.

(g) The force in the prestressing tendons shall not be transferred to the concrete

until the concrete has reached the specified transfer strength. 21.5.10 Pretensioning

(a) The stress in prestressing tendons shall be fully maintained during the period between pretensioning and transfer of stress. Transfer of stress shall take place gradually to minimise shock or damage to the transmission length and shall be carried out in conjunction with the release of any hold-down and hold-up forces in tendon deflectors.

(b) In the long-line method of pretensioning, locator plates shall be distributed

throughout the length of the bed to ensure that the steel wires or wire strands are maintained in the correct positions during concreting. Units which are made in line shall be free to slide in the direction of their length to permit transfer of the prestressing force to the concrete along the whole line.

(c) Moulds used in the individual mould system of pretensioning shall be

sufficiently rigid to provide the reaction to the prestressing force without distortion.

(d) Tendon deflectors in contact with pretensioned prestressing tendons of single

steel wire or wire strand shall have a radius of at least five times the prestressing tendon diameter for steel wire and at least ten times the prestressing tendon diameter for wire strand. The total angle of deflection shall not exceed 15°. If a system is used such that friction develops between prestressing tendons and tendon deflectors, the friction force shall be determined by a test procedure reviewed without objection by the Project Manager and any necessary allowance shall be made.

21.5.11 Post-tensioning

(a) A tensioning schedule shall be submitted to the Project Manager for review without objection at least 7 days before each post-tensioning operation starts. The schedule shall include the proposed sequence of tensioning the prestressing tendons, the required prestressing loads and the calculated extensions of the prestressing tendons.

(b) Spacers used with post-tensioned steel wire or wire strand which are not

tensioned simultaneously shall be sufficiently rigid to ensure that they will not be displaced during successive tensioning operations.

(c) If both ends of the prestressing tendon are free to move, a demonstration

shall be carried out before post-tensioning starts to show that all prestressing tendons are free to move in the ducts.


(d) Post-tensioning shall be carried out in such a manner that the stress in the prestressing tendons increases at a gradual and steady rate. The sequence of tensioning prestressing tendons and the ends of prestressing tendons from which prestress will be applied, shall be reviewed without objection by the Project Manager.

(e) For each element of a structure being stressed, post-tensioning of the prestressing tendons shall be carried out until the required prestress to that element has been reached. Tensioning of each prestressing tendon shall be carried out continuously until the required tendon loads or extensions have been reached. If tensioning is stopped for more than 2 days, particulars of any proposals for remedial or other work shall be submitted to the Project Manager for review without objection and tensioning shall not recommence until the remedial or other work has been carried out and reviewed without objection by the Project Manager.

(f) Measurement of extensions shall not commence until any slack in the

prestressing tendon has been taken up. If the design permits, the draw-in of prestressing tendons at the non-jacking end shall also be measured. The tensioning shall be applied in increments of load and the extensions shall be measured at each increment. The average measured extension of the prestressing tendons shall be within 5% of the calculated extension and the measured extension of individual prestressing tendons shall be within 10% of the calculated extension.

(g) If the tendon deflector in contact with a post-tensioned prestressing tendon

has a radius of less than 50 times the diameter of the prestressing tendon or if the total angle of deflection exceeds 15°, the loss of strength of the prestressing tendon shall be determined by a test procedure reviewed without objection by the Project Manager and any necessary allowance shall be made.

(h) If the pull-in of the tendons at completion of anchoring is greater than that

agreed by the Project Manager, tensioning shall be carried out afresh. (i) The Project Manager may direct that the force in any strand or wire be tested

by re-jacking. The strand or wire shall than be re-anchored at the proper tension.

(j) When the prestressing has been applied, the tendons shall be anchored. The

jack pressure shall then be released in such a way as to avoid shock to the anchorage, tendons, or concrete.

(k) Post-tensioned prestressing tendons shall be cut at a distance from the

anchorage of at least one diameter or 10 mm, whichever is greater. The tendons shall not be cut until at least 1 day after stressing, if the tendon is to be cut before grouting, or alternatively, at least 3 days after grouting.

21.5.12 Protection of External Prestressing Tendons and Anchorages

External prestressing tendons and anchorages shall be protected in their permanent positions from mechanical damage or corrosion until the permanent protection is applied.


21.5.13 Records of Tensioning Operations

Records of tensioning operations shall be kept by the Contractor on Site and a report shall be submitted to the Project Manager for review without objection within 24 hours of each tensioning operation. Tendons shall not be cut prior to the Project Manager's review without objection of the records of each tensioning operation. The report shall contain the following details: (a) location of tensioning operations; (b) coil, heat and bundle numbers of strand used; (c) date and time of starting and completing tensioning operations; (d) weather conditions;

(e) technical personnel supervising or carrying out tensioning operations; (f) prestressing tendon reference numbers; (g) tensioning apparatus identification; (h) measured extensions; (i) pressure gauge or load cell readings; (j) amount of draw-in; and

(k) concrete temperature.

21.5.14 Grouting Equipment

(a) Grout for prestressing systems shall be mixed by a machine capable of producing a homogeneous colloidal grout and of keeping the grout in slow continuous agitation after mixing and until the grouting operation starts.

(b) Grouting equipment shall be capable of continuous operation at a constant

pressure and shall include a system of recirculating the grout when grouting is not in progress.

(c) Grout pumps shall be fitted with a safety valve to prevent the build-up of

excessive pressure. The connection of the pump to the duct shall be by a screw connector or other positive method. Baffles to the pump shall be fitted with 1.18 mm sieve strainers; suction circuits shall be airtight.

(d) Grouting equipment shall be thoroughly washed through with clean water after

every series of grouting operations and at the end of use each day. 21.5.15 Grouting Effectiveness

Grouting of prestressing tendons shall be effective such that the duct is completely filled and the prestressing tendon is completely surrounded with grout.


21.5.16 Grout Injection

(a) The Contractor shall notify the Project Manager before prestressing tendons are grouted and when required, shall allow the Project Manager sufficient time to inspect the tendons which are to be grouted.

(b) Grouting of prestressing tendons shall be carried out as soon as practicable,

and not more than 5 days, after tensioning of the prestressing tendons. (c) Immediately before grouting starts, the ducts shall be thoroughly washed by

pumping clean water through the ducts. The water shall flow through all grout vents. Partial or complete blockage of grout vents shall be cleared before grouting starts. After washing, the ducts shall be blown dry with oil-free compressed air.

(d) Grout shall be used within 30 minutes of mixing unless a retarding agent

reviewed without objection by the Project Manager is incorporated in the grout. If a retarding agent is used, the time shall be determined by a test procedure reviewed without objection by the Project Manager.

(e) The grout pressure applied shall be as low as practicable and shall not exceed 1 MPa. Grout shall be injected from the lower end of ducts. Grout injection shall be continuous and steady and shall be at a rate which will avoid grout segregation and trapping air in the duct. Grout shall be allowed to flow from each of the grout vents until its consistency is equivalent to that of the grout injected. After the last grout vent has been closed, the pressure shall be maintained at 0.5 MPa for 5 minutes. The injection vent shall then be closed under pressure.

(f) If there is any blockage or breakdown or if the grout injection is interrupted,

the duct shall immediately be thoroughly washed with clean water and blown dry with oil-free compressed air; regrouting shall start as soon as practicable.

(g) The filled ducts shall be protected to the satisfaction of the Project Manager to

ensure that:

(i) they are not subjected to shock or vibration within 48 hours of grouting;

(ii) the grout has achieved a strength of not less than 15 MPa before any additional load, arising from the movement of Temporary Works or any construction activity, is applied to concrete containing them; and

(iii) the temperature of the grout does not fall below 3　C for 3 days after its

injection.

(h) The level of grout in grout vents shall be inspected and made good as reviewed without objection by the Project Manager. Making good shall not be carried out until at least 2 days after grouting.

(i) Ducts shall not be grouted when the air temperature in the shade exceeds

32　C or is below 3　C. The temperature of the grout at the point of injection shall not exceed 25　C.


(j) Grouting inlet, outlet and intermediate venting points shall be suitably marked to enable the tendon, to which they refer, to be identified.

(k) The Contractor shall radiographically test grouted ducts if directed by the

Project Manager. 21.5.17 Records of Grouting Operations

(a) Records of grouting operations for prestressing systems shall be kept by the Contractor on Site and a report shall be submitted to the Project Manager for review without objection within 3 days of each grouting operation. The report shall contain the following details:

(i) location of grouting operations;

(ii) date and time of starting and completing grouting operations;

(iii) weather conditions;

(iv) technical personnel supervising or carrying out grouting operations;

(v) prestressing tendon reference numbers;

(vi) grout mix, including any admixtures;

(vii) grout injection pressure;

(viii) volume of grout used; and

(ix) details of any interruptions and topping up.

21.5.18 Tolerances: Sheaths

The line of sheaths shall be within 5 mm of the specified line as shown on the Employer’s Drawings. Sheathing near concrete surfaces shall not infringe the specified tolerance on concrete cover.

21.6 INSPECTION TESTING AND COMMISSIONING 21.6.1 Trial Mixes for Grout

(a) A trial mix for grout for prestressing systems shall be made to demonstrate that the proposed materials, grout mix and methods of production will produce grout which complies with the specified requirements.

(b) The trial mixes shall be completed at least 10 days before the grout mix is

used in the Permanent Works. (c) The Contractor shall notify the Project Manager before making trial mixes. (d) Trial mixes shall be made using the materials, grout mix and methods of

production which have been reviewed without objection by the Project Manager.


21.6.2 Samples: Trial Mixes for Grout

(a) One sample of grout shall be provided from the trial mix to determine the amount of bleeding and free expansion of the grout. The method of sampling shall be as stated in Clause 21.6.23(b).

(b) One sample of grout shall be provided from the trial mix to determine the

crushing strength of the grout. The method of sampling shall be as stated in Clause 21.6.26(b).

21.6.3 Testing: Trial Mixes for Grout

(a) Each sample of grout taken as stated in Clause 21.6.2(a) shall be tested to determine the amount of bleeding and free expansion. The method of testing shall be as stated in Clause 21.6.24(b).

(b) Each sample of grout taken as stated in Clause 21.6.2(b) shall be tested to

determine the crushing strength. The method of testing shall be as stated in Clause 21.6.27.

21.6.4 Non-compliance: Trial Mixes for Grout

(a) If the result of any test for amount of bleeding, free expansion or crushing strength of trial mixes for grout does not comply with the specified requirements for the property, particulars of proposed changes to the materials, grout mix or methods of production shall be submitted to the Project Manager for review without objection. Further trial mixes shall be made until the result of every test complies with the specified requirements for the property.

(b) If grouting trials are carried out using a non-complying trial mix, further

grouting trials shall be carried out. 21.6.5 Grouting trials

(a) Grouting trials for grout for prestressing systems shall demonstrate that the proposed materials, grout mix, methods of production and methods of construction produce a grouted duct which complies with the specified requirements.

(b) Grouting trials shall be completed at least 7 days before grouting starts. (c) The Contractor shall notify the Project Manager before carrying out grouting

trials. (d) Grouting trials shall be carried out using the materials, grout mix, methods of

production and methods of construction, which have been reviewed without objection by the Project Manager.

(e) The profile of ducts and the method of support for grouting trials shall be

submitted to and reviewed without objection by the Project Manager. Vents shall be provided in ducts and tendons shall be pulled tight.


21.6.6 Testing: grouting trials

Three sections selected by the Project Manager shall be cut from the grouted duct and inspected not less than 2 hours after the grout used in the grouting trial has achieved its final set.

21.6.7 Compliance criteria: grouting trials

The sections of grouted duct cut in grouting trials shall be completely filled and the prestressing tendon shall be completely surrounded with grout.

21.6.8 Non-compliance: grouting trials

If the result of any test on sections of grouted duct cut in grouting trials does not comply with the specified requirements for the test, or if in the opinion of the Project Manager any aspect of the grouting procedure as demonstrated by the grouting trial is unsatisfactory, particulars of proposed changes to the materials, grout mix, methods of production or methods of construction shall be submitted to the Project Manager for review without objection and further grouting trials shall be carried out until the result of every test on sections of grouted duct complies with the specified requirements for the test and until in the opinion of the Project Manager every aspect of the grouting procedure is satisfactory. Further trial mixes for grout shall be made unless in the opinion of the Project Manager non-compliance of the grouting trial was not due to the grout mix.

21.6.9 Acceptable Grout Mix

A grout mix which complies with the specified requirements for trial mixes for grout and for grouting trials is defined as an "Acceptable Grout Mix".

21.6.10 Commencement of Grouting

Grouting shall not proceed until the grout mix and grouting procedures have been reviewed without objection by the Project Manager.

21.6.11 Changes in Materials and Methods of Construction

The materials, grout mix, methods of production or methods of construction used to produce an "Acceptable Grout Mix" shall not be changed.

21.6.12 Inspection of Prestressing Systems

The Contractor shall allow sufficient time for the Project Manager to inspect the completed prestressing system before carrying out any work, including concreting and grouting, which will make access to the prestressing system difficult. The Contractor shall notify the Project Manager before carrying out such work.

21.6.13 Testing: Prestressed Units

Testing of prestressed units shall comply with Section 20.


21.6.14 Batch: Prestressing Tendons

A batch of prestressing tendons is any quantity of prestressing tendons of the same type, size and grade, manufactured by the same manufacturer, covered by the same certificates and delivered to Site at any one time.

21.6.15 Samples: Prestressing Tendons

(a) Samples of prestressing tendons shall be provided from each batch of prestressing tendons delivered to Site at least 28 days before installation of the prestressing tendons starts. The number of samples to be provided from each batch shall be as stated in Table 21.1.

(b) The number of specimens in each sample shall be 15. (c) Each specimen shall be 1.5 metre long and straight. (d) Each specimen shall be taken from different coils or bars in the batch. The

ends of specimens shall be cut square without unravelling of wires and loose mill scale and rust shall be removed by wire brushing before delivery to the laboratory.

Table 21.1: Rate of Sampling Prestressing Tendons

Description Size of batch No. of samples per

batch Steel wire 0 - 50 tonnes 1 exceeding 50 tonnes 1 for each 50 tonnes

or part thereof Wire strand and alloy steel bar

0 - 100 tonnes 1 exceeding 100 tonnes 1 for each 100 tonnes

or part thereof 21.6.16 Testing: Prestressing Tendons

(a) Each specimen of prestressing tendons shall be tested to determine the characteristic breaking load, characteristic 0.1% proof load, elongation at maximum load, diameter, cross-sectional area, unit mass and modulus of elasticity. Each specimen of prestressing wire shall also be tested to determine the ductility.

(b) The method of testing shall be in accordance with the following:

High tensile steel wire and strand for the prestressing of concrete : BS 5896 Hot rolled and hot rolled and processed high tensile alloy steel bars for the prestressing of concrete : BS 4486.

(c) Tests shall be carried out on specimens having a temperature between 5°C and 30°C.


21.6.17 Compliance Criteria: Characteristic Breaking Load, Characteristic 0.1% Proof Load

(a) The standard deviations of the results of tests for characteristic breaking load

and characteristic 0.1% proof load, expressed as equivalent stress values, of prestressing tendons shall not exceed the following:

(i) tensile strength : 55 MPa; and (ii) 0.1% proof stress : 60 MPa.

(b) The statistical interpretation of the test results shall be in accordance with

BS 2846:Part 3, Table 3 and BS 2846:Part 4, Table E, both for a one-sided tolerance interval of 0.95 and for a confidence level of 0.95.

21.6.18 Non-compliance : Elongation, Diameter, Cross-sectional Area, Unit Mass,

Modulus of Elasticity, Ductility

(a) If the result of any test for elongation at maximum load, diameter, cross-sectional area, unit mass, modulus of elasticity or ductility of prestressing tendons does not comply with the specified requirements for the property, one additional sample shall be provided from the same batch and additional tests for the property shall be carried out.

(b) The number of specimens in the additional sample shall be 15. (c) The batch shall be considered as not complying with the specified


21.6.19 Testing: Duct Friction

(a) Unless otherwise stated in the Contract, the Contractor shall test, at an early stage of the Contract, two in-place tendons in order to accurately determine friction loss.

(b) Prestressing tendons shall be tensioned from one end and the tendon force

shall be measured at both the jacking and non-jacking ends. (c) The tendon force at the non-jacking end shall be measured by direct-reading

load cells or by a dummy jack of a type reviewed without objection by the Project Manager. A direct-reading load cell or a dummy jack is considered to be suitable as a load-measuring device. The load-measuring device shall be sufficiently rigid to ensure that the movement of the prestressing tendon at the non-jacking end under the specified tendon force is not excessive. The deflection of the load-measuring device shall be measured to an accuracy of 0.5 mm. A load-measuring device with a deflection exceeding 10 mm under the maximum load shall not be used.

(d) The prestressing tendon shall be tensioned to the specified tendon force in

equal increments and the tendon extensions at the jacking end and the tendon force and tendon movement at the non-jacking end shall be measured to within 5 mm. The number of load increments shall be suited to the tensioning operation but shall be at least five.


21.6.20 Compliance Criteria: duct Friction

The force at the non-jacking end of the prestressing tendon determined in the duct friction test shall be within +10% and -5% of the calculated value.

21.6.21 Records of duct Friction Tests

(a) Reports of duct friction tests shall be submitted to the Project Manager for review without objection within 3 days of each test. The report shall contain the following details:

(i) details stated in Clauses 21.4.1 and 21.4.2;

(ii) prestressing tendon reference numbers;

(iii) graph showing tendon forces at jacking end against tendon forces at

non-jacking end; and

(iv) comparison between the calculated tendon forces at the non-jacking end and the measured values.

21.6.22 Batch: Grout for Prestressing Systems

A batch of grout for prestressing systems is any quantity of grout produced in one cycle of operation of a mixer.

21.6.23 Samples: Bleeding and Free Expansion of Grout

(a) For each grout mix one sample of grout shall be provided from each 25 batches of grout, or from the amount of grout produced in one day, whichever is the lesser, to determine the amount of bleeding and free expansion of the grout.

(b) Samples shall be provided and testing shall commence within one hour after

the grout has been mixed. Samples shall be protected from rain before the tests.

21.6.24 Testing: Bleeding and Free Expansion of Grout

(a) Each sample of grout taken as stated in Clause 21.6.23 shall be divided into three specimens; each specimen shall be tested at a temperature of 20°C to determine the amount of bleeding and free expansion.

(b) A portion of each specimen shall be placed in a covered cylinder with a

diameter of 100 ± 10 mm, to a depth of 100 ± 5 mm and the amount of bleeding and free expansion measured by a scale fixed to the outside of the cylinder.

21.6.25 Non-compliance: Bleeding and Free Expansion of Grout

If the result of any test for amount of bleeding or free expansion of grout for prestressing systems does not comply with the specified requirements for the property, particulars of proposed changes to the materials, grout mix or methods of production shall be submitted to the Project Manager for review without objection. Upon review further trial mixes shall be made and further grouting trials shall be carried out.


21.6.26 Samples: Crushing Strength of Grout

(a) For each grout mix one sample of grout shall be provided from each 25 batches of grout, or from the amount of grout produced in a day, whichever is the lesser, to determine the crushing strength of the grout.

(b) Samples shall be provided not more than 1 hour after the grout has been

mixed and shall be protected from rain before test cubes are made. 21.6.27 Testing: Crushing Strength of Grout

(a) Two 100 mm test cubes shall be made from each sample of grout taken as stated in Clause 21.6.26 (a). Each pair of test cubes shall be tested to determine the crushing strength at 7 days.

(b) The method of making, curing and testing the test cubes, and the calculation

of the test results, shall be as stated in Clause 20.8.12(b), (c), (d) and (e), except that compaction of the grout is not required.

21.6.28 Non-compliance: Crushing Strength of Grout

If the result of any test for crushing strength of grout for prestressing systems does not comply with the specified requirements for crushing strength, particulars of proposed changes to the materials, grout mix or methods of production shall be submitted to the Project Manager for review without objection. Upon review further trial mixes shall be made and further grouting trials shall be carried out.

Materials & Workmanship Specification 1/36 January 2011 Issue No. 5, Volume 1 – Civil & Structural Works Section 22 - Steelwork

SECTION 22 STEELWORK 22.1 GENERAL

(a) Allowances shall be made for the deformation due to permanent loads and

the process and sequence of fabrication, erection and construction such that steelwork is completed to within the specified tolerances.

(b) The dimensions shown on the Employer’s Drawings show the required as-

constructed position after deflections due to self weight and superimposed dead loads. The Contractor shall determine any pre-set deflection or camber that may be necessary to ensure that the as constructed position is within the specified tolerances.

(c) The compatibility of the dimensions and setting-out data of steelwork shall be

verified by the Contractor before the materials for steelwork are ordered. 22.2 RELEVANT CODES AND STANDARDS 22.2.1 Steelwork Standards

The use of steelwork shall comply with the Code of Practice for the Structural Use of Steel, Hong Kong. BS 5950:Part 1 & 2:1990 may be used provided the specific requirements as outlined in the Practice Note for Authorized Persons and Registered Structural Engineers (PNAP) No. 160 apply.

22.2.2 Protection of Steelwork

Protection of steelwork against corrosion shall comply with BS 5493.

22.2.3 Amendments to BS 5400 : Part 6

The following amendments shall apply to BS 5400:Part 6:

(a) Contents page :

Delete '6.3.1 General'.

(b) Page 2, Clause 3.1.4.1, lines 5, 8 and 14:

Delete 'C of DD21' and insert 'L1 of BS 5996'.

(c) Page 2, Clause 3.1.4.1, line 10 and Clause 3.1.4.2, line 3:

Delete 'DD21' and insert 'BS 5996'.

(d) Page 3, Clause 4.2.1, line 2:

Delete '4.4.2' and insert '4.2.2'.


(e) Page 3, Clause 4.3.3(e), line 1:

Delete line 1 of text and insert 'the hardness of the edge is reduced to less than 350 HV 30 of BS 427 by a suitable heat treatment'.

(f) Page 4, Clause 4.7.1, paragraph 2, line 4:

Delete '23 of BS 5135' and insert '20 of BS 5135'.

(g) Page 5, Clause 4.14:

Delete and insert:

'The Contractor shall determine the dead load camber of beams required to comply with Section 22.1(a) of this Specification. The camber of plate girders shall be formed by either of the two following alternatives, whichever is stated in the Contract:

Type A cambering : camber introduced by welding the flanges pressed against a web plate cut to a smooth cambered profile; or

Type B cambering : camber introduced by connecting straight sections of girder with a change of slope at their junctions.

Type A camber shall be used if the alternative to be used is not stated in the Contract.

With Type B cambering the junctions shall not be positioned at bolted connections.'

(h) Page 6, Clause 5.2.2, line 2:

Delete 'DD21' and insert 'BS 5996'.

(i) Page 7, Clause 5.5.2, paragraph 3, line 3:

Delete 'grider' and insert 'girder'.

(j) Page 9, Clause 6.3.1:

Delete Clause 6.3.1.

(k) Page 15, Table 5, column 3, Member component 4 :

Delete 'G=0' and insert 'G=D'.


22.3 MATERIALS 22.3.1 Structural Steel

(a) Structural steel shall comply with BS 4360, including Clause B7 at Appendix B, and with BS 5950:Part 2, Section 2.1 with the incorporation of specific requirements outlined in PNAP 160.

(b) Hot rolled sections complying with BS 4:Part 1, BS 4848:Part 2, BS 4848:

Part 4 or BS 4848:Part 5 shall not be replaced with sections complying with other standards unless reviewed without objection by the Project Manager.

22.3.2 Cold formed Sections

(a) Steel for cold formed sections shall comply with BS 1449:Part 1 with the quality grades as stated in the Contract.

(b) Steel for cold formed hollow sections shall comply with BS 6363 with quality

grades as stated in the Contract. (c) Pre-galvanized steel sheet shall comply with BS 2989 with quality grades as

stated in the Contract. 22.3.3 Maximum Carbon Equivalent

Steel used in built-up welded assemblies or at welded connections shall have a carbon equivalent value complying with Table 2 of BS5135.

22.3.4 Steel for Shear Connectors

Steel for headed stud type shear connectors shall have a yield stress of at least 385 N/mm2 and an ultimate tensile strength of at least 450 N/mm2. Steel for other types of shear connectors shall comply with BS 4360.

22.3.5 Bolts, Screws, Nuts and Washers

(a) Bolts, screws and nuts shall comply with the British Standards and strength grades stated in Table 22.1 unless stated otherwise in the Contract.

(b) Washers for high strength friction grip bolts and nuts shall comply with the

following:

(i) high strength friction grip bolts and associated nuts and washers for structural engineering : • general grade : BS 4395:Part 1; • higher grade bolts and nuts and

general grade washers : BS 4395:Part 2; and

• higher grade bolts (waisted shank), nuts and general grade washers

: BS 4395:Part 3;

(ii) load indicating washers for high strength friction grip bolts and nuts shall

be "Coronet" type manufactured by Cooper and Turner or equivalent reviewed without objection by the Project Manager; and.


(iii) plain washers for other bolts, screws and nuts shall comply with BS 4320; tapered washers for other bolts, screws and nuts shall comply with BS 3410; spring washers for other bolts, screws and nuts shall comply with BS 4464.

(c) The surface finish for bolts, screws, washers and nuts shall comply with the

following:

(i) galvanized - BS 729;

(ii) zinc or cadmium plated - electroplating shall comply with either:

BS 3382 for bolts up to and including 20 mm diameter; or BS 1706 Class A for bolts over 20 mm diameter; and

(iii) sherardized - BS 4921.

22.3.6 Welding Consumables

(a) Welding consumables used in metal-arc welding of grades of steel complying with BS 4360 shall comply with BS 5135. Welding consumables used in the fusion welding of steel castings shall comply with BS 4570. Welding consumables used in metal-arc welding of austenitic stainless steels shall comply with BS 4677.

(b) Welding consumables and the procedures used shall be such that the

mechanical properties of the deposited weld metal shall not be less than the respective minimum values of the parent metal being welded.

(c) Welding consumables used with grades of steel other than those complying

with BS 4360 shall be such that the performance requirements stated in BS 5400:Part 6, Table 1 or BS 5950:Part 2, Table 1 as appropriate are achieved.

(d) Electrodes for welding Grade 50 and Grade S355 steels shall be capable of

depositing no more than 15 ml of diffusible hydrogen per 100 g of deposited weld metal, as defined in BS 639.

(e) Covered electrodes for manual metal arc welding shall comply with BS 639. (f) Filler wires for gas-shielded welding shall comply with BS 2901:Part 1. (g) Electrodes shall be kept in unbroken packets in accordance with BS 5135.

Any drying or baking of consumables before issue shall be carried out in accordance with the manufacturer's recommendations.


22.3.7 Rolled Steel Pins

Rolled steel pins, including those made from slabs, shall comply with BS 970:Part 1 or BS 4360, Grades 43, 50 or 55.

Table 22.1 : British Standards And Strength Grades For Bolts, Screws And

Nuts

Type of bolts, screws and nuts

British Standard Strength grade of bolt

Strength grade of nut

High strength friction grip bolts and nuts

BS 4395:Part 1 General grade

as specified in BS4395 : Part 1

Precision bolts, screws and nuts

BS 3692 4.6 4.0

Cup head and countersunk head bolts, screws and nuts

BS 4933 4.6 4.0

Black bolts, screws and nuts

BS 4190 4.6 4.0

Other types of bolts, screws and nuts

BS 4190 4.6 4.0

Hexagon socket screws

BS 4168:Part 1 12.9 12.0

22.3.8 Steel Castings and Cast Steel Pins

Carbon manganese steel castings shall comply with BS 3100. 22.3.9 Steel Forgings and Forged Steel Pins

Steel forgings and forged steel pins shall comply with BS 29. 22.3.10 Stainless Steel

(a) Wrought stainless steel shall comply with BS 970:Part 1, Grade 316 S 16. (b) Flat rolled stainless steel shall comply with BS 1449:Part 2, Grade 316 S 16 in

the softened condition. (c) Stainless steel tubes shall comply with BS 6323:Part 1 and BS 6323:Part 8,

designation LW 23 GZF(S). (d) Stainless steel bolts and nuts shall comply with BS 6105, steel Grade A4 and

property class 80. Stainless steel washers shall comply with BS 1449:Part 2, Grade 316 S 31 in the softened condition. The dimensions and tolerances of bolts and nuts shall comply with BS 3692. The dimensions and tolerances of tapered washers shall comply with BS 3410 and the dimensions and tolerances of flat washers shall comply with BS 4320, Form C.

22.3.11 Grout for Column Bases

(a) Grout for bedding steel bases and for filling bolt pockets and pocket bases shall be cementitious materials based on OPC and shall have the same or greater grade strength as the surrounding foundation concrete. The grout shall contain a non-metallic expanding admixture and shall have a total chloride content of not more than 0.1% by mass of cement.


(b) Grout for bedding steel bases and for filling bolt pockets shall not contain high alumina cement and shall be a proprietary type where stated on the Employer's Drawings or reviewed without objection by the Project Manager and shall be suitable for filling the space by pouring under a suitable head. The proportions of the grout shall be in accordance with the manufacturer's recommendations.

(c) A dry packed mortar may be used for bedding steel bases which exceed

75 mm thick. The mortar shall be cementitious material having the same grade strength of the surrounding concrete and be suitable for thorough ramming against supports such that the space is completely filled.

(d) Grout for filling pocket bases shall be a mix reviewed without objection by the

Project Manager with a nominal maximum aggregate size of 10 mm and have the same grade strength as the surrounding concrete.

22.3.12 Lubricant for Nut Threads of HSFG Bolts

Lubricant for lubricating nut threads of HSFG bolts shall be a wax based type reviewed without objection by the Project Manager. Machine oil and other free flowing lubricants shall not be used.

22.3.13 Paint for Steelwork

(a) Unless otherwise stated in the Contract paint for steelwork shall comply with BS 5493, Section 2, Table 4. Organic zinc-rich paint shall comply with BS 4652. Lead-based paint shall not be used for finishing coats.

(b) Paint shall be supplied in sealed containers of not more than 5 litres capacity.

Each container shall be marked on the side to show the following:

(i) the name of the manufacturer;

(ii) the paint manufacturer's reference number;

(iii) intended purposes, type of pigment and binder;

(iv) batch number, date of manufacture, expiry date and pot life; and

(v) colour, gloss, drying times and flash point. 22.3.14 Marking Steelwork

(a) All steelwork shall be clearly marked for identification and erection purposes as:

(i) identification: The Contractor shall identify all steel elements in

accordance with BS 4360 or BS EN 10025 as applicable, indicating grade, cast number and manufacturer’s identification mark;

(ii) Grade 50 and Grade S355 steel: In addition to marking in accordance

with BS 4360 or BS EN 10025 the Contractor shall mark steel with a continuous pale blue water paint line. The Contractor shall mark immediately, with light blue water paint, any part cut from Grade 50 or S355 steel which does not have a light blue marking;


(iii) cold worked steel: The Contractor shall mark cold worked areas of steel members with orange water paint;

(iv) marking for erection purposes: The Contractor shall tag, hard stamp or

pencil weld each member with an individual identification mark, which can not be obliterated by surface coatings. The Contractor shall submit a Contractor’s Drawing identifying markings and indicating the positions of members in structures; and

(v) permanent identification: The Contractor shall supply and fix to each

structure after erection, a brass identification plate. The plate shall indicate with lettering not less than 15 mm high, etched or punched to a depth not less than 1.5 mm, the following: • grade of steel in structure; and • date of fabrication.

22.3.15 Handling and Transport of Steelwork

(a) Steelwork shall not be subject to rough handling, shock loading or dropping from a height.

(b) During handling and transport of coated steelwork, the steelwork shall be

separated from wires, lashings, supports and other steel by rubber padding in such a manner that the coatings are not damaged or discoloured. The Contractor shall take such measures to prevent permanent distortion such as stiffening free ends and protecting machined surfaces.

(c) Steelwork shall not be lifted from the painting bed until the last applied coating

is sufficiently dry or cured for handling. (d) Rivets, bolts, nuts, washers, screws and small plates and articles shall be

packed in containers marked to identify the contents. (e) For road transport the Contractor shall:

(i) provide intermediate supports to which a component can be tied with

strops to prevent oscillation; and

(ii) sit components on softwood supports covered with soft clean pads.

(f) For sea transport the Contractor shall:

(i) containerise all steelwork; (ii) pack containers so that no components touch; (iii) use softwood with soft padding and man-made fibre ropes and strops to

prevent movement and contact;

(iv) bag fasteners and accessories;

(v) bundle small components and prevent contact; and

(vi) chromate dip galvanized steel, which is not to be overcoated, when it will be containerised for longer than three weeks.


22.3.16 Storage of Steelwork

(a) Steelwork shall be stored off the ground on level supports in well drained areas in a manner which will not result in damage or deformation to, or in contamination of, the steelwork or coatings. Packing shall be placed between steelwork which is stacked.

(b) Covered places in which steelwork is stacked shall be ventilated. (c) Different types and sizes of steelwork shall be stored separately. (d) Steelwork shall not be stored on or adjacent to concrete surfaces which form

part of the Permanent Works. (e) Steelwork shall be protected from exposure to conditions which may affect the

steelwork or coatings. (f) Wet paint films, steelwork surfaces which are to be primed or overcoated and

joint surfaces which are to be assembled shall be protected from exposure to conditions which may affect the film or surface.

(g) Except as stated in Section 22.3.16(h) and (i), steelwork shall be stored in an

enclosed workshop and protected from conditions which may affect the steelwork after it has been cleaned as stated in Section 22.5.12 until the following times:

(i) when the second undercoat to painted steelwork has hard dried;

(ii) when the coating process to galvanized, electroplated or metal sprayed

steelwork has been completed;

(iii) when the sealer to metal sprayed and sealed steelwork has been completely absorbed; and

(iv) when the first undercoat to metal sprayed and painted steelwork has

hard dried.

(h) Primed steelwork surfaces may be exposed outside the enclosed workshop for a period not exceeding two weeks.

(i) Micaceous iron oxide undercoats to steelwork may be exposed outside the

enclosed workshop for the minimum period necessary to move the steelwork from one part of the workshop to the other. Undercoated surfaces shall be covered when the steelwork is being moved.

(j) All painted steelwork shall be checked for undercoat contamination prior to

the application of subsequent coats.

(k) Steel members shall be stored and stacked such that markings are clearly visible.


22.3.17 Storage of Paint

Paint and associated materials shall be stored in sealed containers marked as stated in Section 22.3.13(b) and protected from exposure to conditions which may affect the material. The materials shall be stored in accordance with the manufacturers' recommendations and shall not be used after the recommended expiry date. The materials shall be stored in a locked store.

22.3.18 Metal Coatings to Steelwork

(a) Galvanized coatings shall be applied by hot-dip galvanizing in accordance

with BS 729. The coating thickness shall comply with BS 729, Table 1. (b) Sherardized zinc coatings shall comply with BS 4921, Table 1, Class 1. (c) Sprayed zinc and aluminium coatings shall comply with BS 2569:Part 1. The

nominal coating thickness shall be 100 µm. The sprayed metal shall be pre-treated with product CP1 and sealed with product CP3C in accordance with BS 5493.

(d) Electroplated zinc and cadmium coatings on threaded components with a

diameter not exceeding 36 mm shall comply with BS 3382:Parts 1 and 2. The coating thickness shall be at least 5 µm.

(e) Metal coatings which will be overcoated with paint shall not be passivated and

shall be treated in accordance with the manufacturer's recommendations for the specific coating system selected.

(f) Allowance for the thickness of the metal coating shall be made in the sizes of

the threads of metal coated threaded components. Nuts shall not be tapped oversize by more than 0.4 mm. Metal coated HSFG bolts and nuts shall not be tapped oversize.

(g) Damaged areas of metal coatings shall be rubbed down to remove excessive

roughness, cleaned and made good with a compatible coating of a type reviewed without objection by the Project Manager.

(h) Metal coatings required on part of a component shall be completed before the

rest of the component is painted. (i) Chromium plating shall comply with BS 4641.

22.3.19 Painting Systems for Steelwork

(a) The painting system to be used for steelwork shall be as stated in the

Contract. (b) The different types of paints within each painting system shall be compatible

with each other and shall be manufactured by the same manufacturer. Successive coats in a painting system, including stripe coats, shall be in contrasting colours to aid identification.


22.4 SUBMISSIONS 22.4.1 Particulars of Steel

(a) The original or certified true copy of the manufacturer's mill certificates for steel shall be submitted to the Project Manager for review without objection in accordance with BS 4360, Clause 12 and Appendix B 6.

(b) The mill certificates shall be submitted to the Project Manager not more than

7 days after the steel has been delivered to the place of fabrication. 22.4.2 Particulars of Shop Drawings

(a) Two sets of Contractor’s Drawings of the steelwork shall be submitted to the Project Manager for review without objection at least 6 weeks before fabrication of the steelwork starts. These Contractor’s Drawings shall show details of the following:

(i) general arrangement drawings including plans, elevations and sections

showing the location and setting out of all members and assemblies;

(ii) drawings showing the individual members and assemblies, including dimensions, member sizes, precambers, splice positions, bolts, penetrations, fixings and all other information to fully describe the intended fabrication;

(iii) welds, including any stud welds, marked with the relevant welding

procedures;

(iv) joints or non-standard welds proposed by the Contractor;

(v) locations and method of removal of any temporary welded attachments proposed by the Contractor;

(vi) edges of steelwork complying with BS 5400:Part 6 to be formed by

flame cutting or shearing procedures complying with BS 5400:Part 6, Clause 4.3.3(a), (d) or (e) with the edges marked with the procedures to be used;

(vii) parts of steelwork complying with BS 5400:Part 6 to be worked by hot

processes complying with BS 5400:Part 6, Clause 4.8, 4.9 or 4.10 with the parts marked with the processes to be used; and

(viii) details of holding down bolts and fittings to be cast into the concrete or

masonry.

(b) Fabrication work shall not commence until the Contractor’s Drawings and the associated method statements have been reviewed without objection by the Project Manager.


22.4.3 Particulars of Method of Erecting Steelwork

(a) The following particulars of the proposed method of erecting steelwork shall be submitted to the Project Manager for review without objection:

(i) sequence and method of erection of steelwork;

(ii) method of lifting and handling the components;

(iii) method of preventing damage to protective coatings on steelwork during

handling;

(iv) procedure for aligning, levelling and plumbing steelwork, including temporary supports and method of making beddings for column bases;

(v) sequence of casting concrete bonded to the steelwork; and

(vi) calculations of erection stresses.

22.4.4 Welder Certificates

(a) Certificates endorsed by an independent HOKLAS accredited inspecting authority shall be submitted to the Project Manager for review without objection to show that each welder has been approved in accordance with BS 4570, BS 4871:Part 1 or BS 4872:Part 1 as appropriate. The extent of approval of the welder shall be appropriate to the categories of welds which he will carry out.

(b) The welder certificates shall be submitted at least 2 weeks before fabrication

of the steelwork starts. 22.4.5 Particulars of Welding Procedures

(a) The following particulars of the proposed welding procedures shall be submitted to the Project Manager for review without objection:

(i) welding procedures in accordance with BS 5135, Clause 20 for each

type and size of weld;

(ii) documentation endorsed by an independent HOKLAS accredited inspecting authority to show that the welding procedure has complied with the procedure trial requirements stated in the Contract in previous tests, or that the welding procedure for steel castings complies with the exemption criteria stated in BS 4570, Clause 20.1.1; and

(iii) records of approval tests as stated in Clause 22.6.7 (a) if procedure

trials are required under Clause 22.6.1 (a).


22.4.6 Particulars of Stud Welding, Flame Cutting and Shearing Procedures

(a) The following particulars of the proposed stud welding, flame cutting and shearing procedures for steelwork complying with BS 5400:Part 6 shall be submitted to the Project Manager for review without objection: (i) procedures for stud welding, flame cutting and shearing processes

complying with BS 5400:Part 6, Clause 4.3.3(a), (d) or (c); (ii) documentation endorsed by an independent HOKLAS accredited

inspecting authority to show that the stud welding, flame cutting or shearing procedure has complied with the procedure trial requirements stated in the Contract in previous tests; and

(iii) report of procedure trials as stated in Clause 22.6.7 (a) if procedure

trials are required under Clause 22.6.1 (a).

22.4.7 Particulars of Vent Holes for Galvanizing

Particulars of the method of plugging vent holes required for hot-dip galvanizing hollow or box sections shall be submitted to the Project Manager for review without objection.

22.4.8 Particulars of Method of Non-destructive Testing

Particulars of the proposed method for carrying out non-destructive testing on welds shall be submitted to the Project Manager for review without objection.

22.4.9 Particulars of Inspecting Authority and Testing Consultant

(a) The name of the proposed independent HOKLAS accredited inspecting authority endorsing welder certificates and records of approval tests for welding procedures shall be submitted to the Project Manager for review without objection.

(b) The name of the proposed testing consultant stated in Section 22.6.13 shall

be submitted to the Project Manager for review without objection. 22.4.10 Particulars of Paint

(a) The following particulars of the proposed paints and associated products shall be submitted to the Project Manager for review without objection:

(i) name of manufacturer;

(ii) duplicate copies of the manufacturer's data sheets including

temperature, humidity, method of application and other conditions at the workshop or on Site under which the paint is to be applied; and

(iii) manufacturer's product specifications, product range and technical

information.



(a) A representative sample of blast cleaned steel plate shall be submitted to the Project Manager for review without objection. The sample shall be 150 mm x 150 mm x 6 mm and shall be enclosed in a sealed, colourless, transparent wrapping. The grade of steel and the method of blasting shall be representative of those which will be used in the Permanent Works.

(b) Two representative samples of painted metal plates for each painting system

shall be submitted to the Project Manager for review without objection. Each plate shall be 150 mm x 75 mm x 1 mm and shall have smooth edges and 10 mm corner radii. The plates shall be brush cleaned and painted on one face with the painting system in such a manner that each coat is stepped back from the underlying coat in equal strips. The degree of gloss of the finishing coat shall be reviewed without objection by the Project Manager.

(c) Representative samples of each type of nut, bolt, washer, stud and rivet shall

be submitted to the Project Manager for review without objection. 22.5 WORKMANSHIP 22.5.1 Fabrication of Steelwork

Fabrication of steelwork shall comply with BS 5400:Part 6, Clauses 4.1 to 4.16 or BS 5950:Part 2, Sections 3 and 4 as appropriate except as stated in Sections 22.5.2 to 22.5.11 and 22.6.12.

22.5.2 Welding, Heating and Cutting

(a) Welding shall only be carried out by welders who possess a valid welding certificate for the appropriate category of welding. A welder shall cease to carry out welding if any of the circumstances stated in BS 4570, Clause 21.1, BS 4871:Part 1, Clause 11 or BS 4872:Part 1, Clause 6 as appropriate occur.

(b) Pre-setting, pre-bending, skip welding, back-step techniques and other

measures shall be taken as necessary to counteract shrinkage or distortion due to welding, gouging, thermal cutting or heat treatment.

(c) Butt welds shall be complete penetration butt welds made between fusion

faces. (d) Butt welds in each component part shall be completed before the final

assembly of built-up assemblies. (e) To ensure full throat thickness at the ends of butt welds run-on and run-off

plates shall be used. These plates shall comply with the following :

(i) identical material to that being welded;

(ii) prepared in the same manner as the parts being joined;

(iii) removed by cutting after completion of welding;


(iv) the surfaces where plates were attached shall be ground smooth and inspected for cracks;

(v) welding of austenitic stainless steel shall be carried out in accordance

with BS 4677;

(vi) temporary welded attachments for either fabrication or erection shall comply with BS 5135 and shall be reviewed without objection by the Project Manager;

(vii) welding, heating or thermal cutting processes which give off toxic or

irritant gases shall not be used;

(viii) tack welds shall comply with BS 5135;

(ix) materials, procedures, fixing and equipment for shear studs shall be in accordance with the manufacturer's recommendations; and

(x) slag shall be removed by light hammering, wire brushing or other

methods which will not deform the surface of the weld.

22.5.3 Length of Bolts

The length of HSFG bolts shall comply with BS 4604:Part 1 or BS 4604:Part 2 as appropriate. The length of bolts complying with BS 3692, BS 4190 and BS 4933 shall be such that the end of the bolt shall project above the nut by at least one clear thread, but by not more than one nominal bolt diameter, and at least one clear thread plus the thread run out is clear between the nut and the unthreaded shank of the bolt, after tightening.

22.5.4 Length of Threads

The length of threads on bolts shall be determined in accordance with BS 3692, BS 4190, BS 4395:Part 1, BS 4395:Part 2, BS 4395:Part 3 or BS 4933 as appropriate. If additional locknuts or other nuts are specified, the thread length shall be increased by one nominal bolt diameter for each additional nut.

22.5.5 Bolt Holes

(a) Bolt holes shall be formed by drilling, punching or reaming. (b) Except in steel base plates or where otherwise noted on the Employer's

Drawings the size of holes for ordinary bolts shall be of diameter not more than 2 mm greater than the diameter of the bolts for bolts up to 24 mm diameter, and not more than 3 mm greater than the diameter of the bolt for bolts over 24 mm diameter.

(c) Holes for HSFG fasteners shall comply with BS 4604. (d) Bolt and vent holes in hollow sections shall be sealed to prevent the ingress of

moisture. Where not specified on the Employer's Drawings the method shall be proposed on the Contractor’s Drawings submitted in accordance with Section 22.4.2.


22.5.6 Use of Nuts (a) Nuts shall not be used with bolts or screws which comply with a different

standard. (b) Bolt assemblies shall be in such a condition immediately before installation

that the nut turns freely on the bolt. (c) Nuts in galvanized assemblies shall be re-tapped after galvanizing. (d) Nuts shall be secured in connections subject to vibration or reversal of

stresses to prevent loosening. If not shown on the Employer's Drawings, the proposed method shall be shown on the Contractor’s Drawings submitted in accordance with Section 22.4.2.

22.5.7 Use of Washers

(a) Washers for HSFG bolts shall be provided in accordance with BS 4604:Part 1 or BS 4604:Part 2 as appropriate. Washers shall be provided for bolts complying with BS 3692, BS 4190 and BS 4933 under the nut or bolt head, whichever is rotated during tightening, if the parts to be connected are to be coated with protective coatings before assembly. Washers shall be provided under the nuts and heads of bolts in oversized and slotted holes.

(b) Tapered washers shall be used under bolt heads and nuts bearing on

surfaces sloping 3° or more from a plane at right angles to the bolt axis.

(c) Bolt assemblies containing spring washers shall be tightened until the spring washer is completely flattened.

22.5.8 Tightening of Bolts

Bolts shall be tightened in accordance with BS 5950:Part 2 and in such a manner that the contact surfaces of permanent bolted joints are drawn into close contact.

22.5.9 Tightening of HSFG Bolts

(a) The degree of preliminary tightening of bolts and nuts complying with BS 4395:Part 1 which are tightened by the part turn method shall be torque controlled. The tightening equipment for preliminary tightening shall be calibrated with a bolt load meter. The value of bedding torque for the preliminary tightening shall be within 10% of the values stated in Table 22.2.

(b) Bolts and nuts at each joint with bolts or washers with load indicating devices

shall be initially tightened to bring the faying surfaces into close contact over the full area. The range of the average gap after initial tightening shall be reviewed without objection by the Project Manager. The bolts and nuts shall be re-tightened if necessary to close the average gap back to the agreed range. After all bolts and nuts at the joint have been initially tightened, the bolts and nuts shall be finally tightened to attain the shank tension stated in BS 4604:Part 1 or BS 4604:Part 2 as appropriate. The range of average gap corresponding to the required shank tension shall be established for each batch as defined in BS 4395:Part 1 or BS 4395:Part 2 as appropriate by testing at least three bolt, nut and washer assemblies in a bolt load meter and shall be reviewed without objection by the Project Manager. The average gap after final tightening shall be within the established range.


(c) The threads of nuts for HSFG bolts which are to be tightened by the part turn method or the load indicating method shall not be lubricated unless reviewed without objection by the Project Manager. If the use of lubricant is permitted in the part turn method, the bedding torque shall be established by a bolt load meter and shall be reviewed without objection by the Project Manager. The lubricant shall be applied at the place of manufacture and shall only be applied to the nut threads. The bearing surfaces of the nuts and the faying surfaces shall not be contaminated with the lubricant.

(d) The bolt load meter for measuring bolt shank tension in the part turn, torque

control or load indicating methods of tightening shall be calibrated by a laboratory reviewed without objection by the Project Manager before tightening of bolts and nuts starts and at regular intervals reviewed without objection by the Project Manager. During re-calibration, a replacement calibrated bolt load meter shall be provided on Site. Calibration results shall be submitted to the Project Manager for review without objection at least one week before the bolt load meter is used.

(e) If after tightening, a bolt or nut is slackened-off for any reason, the complete

bolt assembly shall be discarded and not re-used in the Permanent Works. (f) The faying surfaces for HSFG fasteners shall be in accordance with the

following :

(i) mill scale shall be removed;

(ii) free from distortion, deformities or contaminants which may reduce the slip factor below the design value; and

(iii) deformed surfaces shall be machined flat and tested in accordance with BS 4604 to determine the slip factor after machining.

(g) Following complete assembly of all bolted connections, the fit and tightness of

the bolts shall be checked at locations reviewed without objection by the Project Manager.

(h) Prior to Site painting of HSFG bolted connections the following shall be

confirmed :

(i) minimum shank tension has been obtained; and

(ii) appropriate hardened washers have been fitted in accordance with the requirements of BS 6404.

Table 22.2 : Bedding Torque For HSFG Bolts

Nominal diameter of bolt ( )

Bedding torque (N.m) 16 80 20 160 22 210 24 270 27 340 30 460


22.5.10 Movement Connections (a) Where slotted holes are provided for movement connections, the joints shall

be free to move. (b) Bolted movement connections shall be formed as follows:

(i) the slotted hole shall be wider than the unslotted hole;

(ii) shouldered bolt shall be used with a spring washer under the head and shoulder bearing on the faying surface of the unslotted member; and

(iii) a flat washer shall be provided under the nut and the nut tightened into

the unslotted member. 22.5.11 Defects in Steelwork

Defective components for steelwork shall not be used in the Permanent Works unless repair of the defects is permitted by the Project Manager. If permitted, defective components shall be repaired by methods reviewed without objection by the Project Manager.

22.5.12 Cleaning of Steelwork and Coated Surfaces

(a) Soil, concrete and other adherent matter shall be removed immediately from

steelwork or coated surfaces and the surfaces shall be made good by methods reviewed without objection by the Project Manager.

(b) Dust, soot, grit, detritus, metallic or other loose particles shall be removed by

vacuum cleaning after steelwork surfaces have been blast cleaned or before coated surfaces are washed or steam cleaned.

(c) Oil and grease shall be removed by emulsion cleaners, by steam cleaning or

by high pressure water jets before removing rust and mill scale or overcoating. Oil and grease shall not be removed by turpentine or other solvents. If steam cleaning is used, steam cleaning shall be carried out after the greasy deposits have been removed by scraping and a detergent shall be added to the feed water of the steam generator.

(d) Salts, chemicals, corrosion or paint degradation products, including zinc salts

on zinc coatings or zinc-rich paints, shall be removed by washing with detergent solution and rinsed with fresh water before coating steelwork surfaces or overcoating.

(e) Rust spotting on blast cleaned surfaces shall be rejected and steel shall be re-

blasted to the required standard before any coating is applied. (f) Residual salts resulting in measurements higher than 90 ppm shall be

removed by high pressure fresh water washing. (g) The final shop coats on external surfaces shall be thoroughly washed with a

detergent solution at Site before being overcoated.


(h) Finished coated surfaces shall be cleaned as stated in Sections 22.5.4(b) to (d) not more than 14 days before application for the Completion Certificate for the Works.

(i) Cleaning agents to be used shall be reviewed without objection by the Project Manager. Surfaces which have been cleaned using cleaning agents shall be rinsed with water to remove all traces of the cleaning agent.

(j) Cleaning tools shall not damage the surfaces being cleaned. Wire brushes

and brooms shall not be used for cleaning coated surfaces. 22.5.13 Preparation of Steelwork Surfaces

(a) Bare metal surfaces of steelwork which are to be painted or metal coated shall be treated before rust and mill scale are removed in accordance with the following requirements:

(i) burrs, arrises and serrations shall be smoothed by grinding or filing. All

surface irregularities shall be removed, including sharp edges and laminations, by grinding until smooth; and

(ii) weld spatter, weld slag and raised metal laminations shall be removed

by grinding or chipping and the surface shall be made good.

(b) At no time shall steel surfaces have rusted beyond Rust Grade C of Swedish Standard S1S 05 59 00.

(c) Rust and mill scale shall be removed from steelwork which is to be metal

coated in factories by a pickling process compatible with the metal coating process.

(d) Rust and mill scale shall be removed from steelwork which is to be metal

sprayed by blast cleaning carried out in accordance with BS 2569:Part 1, Clause 3.

(e) Rust and mill scale shall be removed from steelwork to be painted by blast

cleaning as stated in Section 22.5.14 unless the use of acid-pickling, mechanical cleaning or flame cleaning as stated in Sections 22.5.15 to 22.5.17 has been reviewed without objection by the Project Manager.

(f) Excess acid or other chemicals used in the pickling process shall be removed

from steelwork which has been prepared by pickling before the application of the metal coating. Pickling shall not be carried out for longer than is necessary to remove the rust and mill scale.

(g) After surface preparation has been completed, the surface roughness shall be

compatible with the specified coating and at no location should the peak-to-trough amplitude exceed 80 m.　

(h) All defects in the substrate surface exposed during surface preparation which

are not acceptable in accordance with BS 4360 shall be rectified in accordance with BS 4360.

(i) Defects which are acceptable in accordance with BS 4360 but which will

prevent the satisfactory coating of the steelwork shall be rectified and reviewed without objection by the Project Manager.


(j) Steelwork which has rusted to Rust Grade B of Swedish Standard SIS 05 59 00 at any stage before surface preparation, and steel which has been subject to significant contamination prior to blast-cleaning, shall be tested in accordance with Appendix G of BS 5493 after surface preparation, to demonstrate that the prepared surface is substantially free of salts.

(k) Prefabrication coatings may be applied but this coating will be considered

additional to the main protective-system. If a prefabrication coating is to be applied the Contractor shall provide evidence that it is fully compatible with the main protective system.

22.5.14 Blast Cleaning of Steelwork

(a) Blast cleaning of steelwork shall be carried out to second quality of surface finish in accordance with Sa2½ in Swedish Standard SIS 05 59 00 using chilled iron abrasive.

(b) Chilled iron grit shall be graded in accordance with BS 2451. The maximum

size of grit shall be G17 for use in automatic impeller type equipment and shall be G12 for manual or compressed air equipment. The difference in level between a peak and the adjacent trough of the blasted surface profile shall not exceed 0.1 mm or in accordance with the paint manufacturer's recommendation.

(c) All compressed air for grit blasting shall be passed through aftercoolers and

oil separation equipment to ensure that the air is dry and oil free. Air shall be tested each day by placing a white cloth at the compressed air outlet for one minute. The cloth shall remain clean after one minute.

(d) Abrasives shall not contain materials which may contaminate the steel

surfaces and shall be cleaned and free of chloride, dust, dirt, grease, oil and moisture. Sand shall not be used except in a wet cleaning system. Expandable abrasive shall be used once only. Recyclable steel abrasive shall be cleaned and free of contaminants before re-use. Recyclable abrasives shall be discarded when the particle size fails to achieve the specified profile.

(e) Blast cleaning shall be carried out in a fully enclosed environmentally

controlled space separated from the place of painting. The enclosed space shall be fitted with dust extractors and filters to prevent the dispersal of dust outside the enclosed space.

22.5.15 Acid-pickling of Steelwork

Acid-pickling of steelwork shall be carried out by the Footner process in accordance with BS 5493, Clause 14.3.2. The first priming coat of paint shall be applied as soon as the steel has dried and is still warm.

22.5.16 Mechanical Cleaning of Steelwork

Mechanical cleaning of steelwork shall be carried out using carborundum grinding discs or other power-driven tools followed by steel wire brushing and dusting to remove all loosened material which is not firmly bonded to the metal surface. Excessive burnishing of the metal through prolonged application of rotary wire brushes shall not be carried out. Visible peaks and ridges shall be removed. Pneumatic chipping hammers shall not be used.


22.5.17 Flame Cleaning of Steelwork

(a) Flame cleaning of steelwork shall not be carried out at the following locations:

(i) within 2 m of HSFG bolts, cold worked high tensile steel and surfaces already coated with paint or cadmium, lead-based or carbonaceous materials, or

(ii) on sections thinner than 0.5 mm.

(b) Flame cleaning shall be carried out without distorting the steelwork and

without adversely affecting the properties of the steel. The temperature of the steel surface being flame cleaned shall not exceed 200°C.

(c) Loose materials shall be removed from the flame-cleaned surface by wire

brushing followed by blowing dry air or vacuum cleaning. The priming coat shall be applied when the surface temperature of the steel is between 35°C and 40°C. Surfaces with temperatures of less than 35°C shall be reheated.

22.5.18 Cleaning of Bolts, Nuts and Washers

Bolts, nuts and washers for steelwork shall be kept free from dirt and deleterious material. Oil and grease on bolts, nuts and washers, other than lubricants reviewed without objection by the Project Manager for nuts of HSFG bolts, shall be removed before assembling and coating the exposed parts of assembled bolts, nuts and washers.

22.5.19 Inspection of Surface Preparation

Surfaces shall not be coated until the cleaning and preparation of the surfaces has been carried out. The Contractor shall notify the Project Manager when the surfaces are available for inspection.

22.5.20 Application of Paint to Steelwork

(a) Surfaces which are to be painted shall be dry immediately before paint is applied.

(b) Paint shall be taken from the paint store ready for application. Thinning, if

necessary, shall be carried out in the paint store using the type of thinner in the ratio stated in the manufacturer's data sheets.

(c) Paint shall be applied by brush, by air pressure spray or by airless spray.

Sealer and primers shall be applied by continuous spraying. (d) Each coat in the paintwork system shall be sufficiently dry or cured before the

next coat is applied. The time between application of successive coats shall be within the limits recommended by the manufacturer and the limits stated in Section 22.5.22.

(e) Paints having a pot life specified by the manufacturer, including two pack

paints and moisture cured paints, shall be discarded on expiry of the pot life or at the end of each working day, whichever comes first. Other paints in opened containers shall be kept in sealed containers with not more than 10% ullage in store after each day's work and shall not be thinned or mixed with fresh paint when re-issued for another day's work.


(f) All connections, including fasteners, items of bracketry and other small pieces fabricated separately to the main steelwork shall be prepared and protected using an equivalent standard to the adjacent steel unless otherwise stated in the Contract. If the Contractor proposes to use a different protective system for any part of a connection to that used for the adjacent steel, evidence shall be submitted to the Project Manager which demonstrates compatibility.

(g) Paint shall not be applied to friction grip interfaces. The faying surfaces shall

be masked to prevent rusting beyond Rust Grade C of Swedish Standard SIS 05 59 00. If galvanizing or other metal coatings have been applied, evidence shall be provided to demonstrate that a slip factor not less than the design value shall be achieved.

(h) Bolt connections in externally exposed steelwork, other than friction grip

connections, shall be assembled with a coat of primer still wet on the contact surfaces.

(i) Plated, galvanized or sherardized bolt assemblies shall be primed with a

compatible etch primer or treated with a mordant solution prior to overcoating.

(j) After erection some parts of the steelwork may not be accessible for the application of site-applied coatings. The complete system shall be applied prior to erection of these areas.

22.5.21 Working Conditions for Painting

(a) Paint shall not be applied to steelwork under the following conditions:

(i) when the ambient temperature falls below 4°C or the relative humidity rises above 90%;

(ii) for outdoor work, during periods of inclement weather including fog,

frost, mist and rain or when condensation has occurred or is likely to occur on the metal;

(iii) when the surface temperature of the metal to be painted is less than

3°C above the dew point of the ambient air; or

(iv) when the amount of dust in the air or on the surface to be painted is in the opinion of the Project Manager excessive.

(b) Two pack paints of the epoxide resin type shall not be applied and cured

when the temperature is below that recommended by the manufacturer. 22.5.22 Priming and Overcoating Time Limits

(a) Blast cleaned steel shall be primed or metal coated within 4 hours after blast cleaning and before any visible signs of oxidations appear on the prepared surface. Prepared surfaces shall be blown clean with dry, oil free compressed air to remove dust, dirt and grit residues before coating.

(b) Primed steel surfaces shall be overcoated within 8 weeks after priming.

(c) Second undercoats shall be applied within 72 hours after application of the

first undercoat.


(d) Sealer or etch primer to sprayed metal shall be applied within 4 hours after spraying. The etch primed surfaces shall be overcoated within 72 hours after priming.

(e) Etch primer to galvanized steelwork shall be applied within 14 days after

delivery of the steelwork to Site. The etch primed surfaces shall be overcoated within 48 hours after priming. Prior to application of the etch primer to galvanized steelwork the surface shall : (i) be treated with "T"-wash in accordance with BS 5493, Section 2, Clause

11.3.2; (ii) have the "T"-wash removed in accordance with BS 5493; and (iii) be completely dry.

(f) Overcoats to two pack paints of the epoxide or polyurethane type shall be

applied within 48 hours after application of the two pack paint. If it is not possible to overcoat within 48 hours, the two pack paint shall be abraded to produce a roughened surface and shall be given a flash coat of primer of a type reviewed without objection by the Project Manager; the primer shall be allowed to dry for at least 4 hours before application of the next coat of the system.

22.5.23 Stripe Coats to Steelwork

Immediately after the first undercoat of the painting system to steelwork has dried, a stripe coat of undercoat paint shall be applied by brush to edges, corners, crevices, exposed parts of bolts, nuts, rivets and welds. Another stripe coat of finishing paint shall be applied in the same manner after the last undercoat has dried.

22.5.24 Paint Coats to Steelwork

(a) The dry film thickness of the paint coats to steelwork shall be measured using a magnetic dry film thickness gauge. The total dry film thickness shall be measured at spacings of approximately 1.0 m. If the measured dry film thickness is less than 75% of the specified nominal dry film thicknesses or if more than 10% of the measured dry film thickness are less than 95% of the specified nominal dry film thickness, repair work shall be carried out as stated in Clause 22.5.26.

(b) Dry film thickness readings on structural members shall be taken at three

points for each linear metre. Wet film thickness gauges shall not be used as a means of predicting the dry film thickness, but only as an indication that sufficient material has been applied at the time of application.

(c) Each coat of paint shall be free from embedded foreign matter, mechanical

damage and surface defects, including bittiness, blistering, brush marks, bubbling, cissing, cracking, cratering, dry spray, floating, pinholing, rivelling, runs, sagging, spotting and spray mottle as defined in BS 2015. The finished paintwork system shall have an even and uniform appearance.

(d) Each coat of paint shall adhere firmly to the substrate without blistering,

chipping, flaking or peeling. Adhesion tests in accordance with BS 3900:Part E6 shall be carried out on representative areas to confirm that the adhesion of the completed paint scheme is equivalent to classification 2 of that standard. The test area shall be repaired in accordance with the Specification.


22.5.25 Etch Primers and Blast Primers

Etch primers and blast primers shall not be applied on phosphated steel and shall not be overcoated with zinc-rich primers.

22.5.26 Repairs to Damaged Areas of Paint

(a) Areas of paint to steelwork which have been damaged shall be cleaned to bare metal or to the metal coating. The edges of the undamaged paint shall be bevelled.

(b) The full specified painting system shall be restored in such a manner that

each new paint coat overlaps the existing paint by at least 50 mm all round the affected part.

22.5.27 Protection of HSFG Bolted Joints

(a) The faying surfaces of HSFG bolted joints in steelwork which is metal sprayed overall and sealed or metal sprayed and painted overall, shall be coated with the sprayed metal. The sealer on the parent material shall extend for a distance of between 10 mm and 20 mm inside the perimeter of the faying surfaces. Free surfaces and edges of the joint material shall be coated with the same sealer.

(b) The joint material and the faying surfaces on the parent material of steelwork

which is metal sprayed only at joints and painted overall shall be metal sprayed. The sprayed metal on the parent material shall extend for a distance of between 10 mm and 20 mm outside the perimeter of the faying surfaces. The primer on the parent material shall extend for a distance of between 10 mm and 20 mm inside the perimeter of the faying surfaces. Sprayed metal on the free surfaces and edges of the joint material shall be coated with a sealer which is compatible with the painting system.

(c) The primer on the parent material of steelwork which is painted overall and

uncoated at faying surfaces of HSFG bolted joints shall extend for a distance of between 10 mm and 20 mm inside the perimeter of the faying surfaces.

22.5.28 Protection of other Shop-bolted Joints

Blast primer for painted steelwork or sprayed metal plus sealer for metal sprayed steelwork shall be applied to the joint and parent material of shop-bolted joints other than HSFG bolted joints; joints for painted steelwork shall be assembled after the first undercoat of the painting system has been applied to the contact surfaces and while the undercoat is still wet.

22.5.29 Protection of other Site-bolted joints

Surfaces of the parent and joint material of Site-bolted joints other than HSFG bolted joints shall be coated with the same protective system as the parent material.

22.5.30 Protection of Welded Joints

Welds and steelwork surfaces which have been affected by welding shall be coated with the same protective system as the parent material.


22.5.31 Joints made after Coating the Parent Material

(a) Hot-dip galvanizing and electroplating to steelwork shall not be carried out until all welds for the steelwork which is to be galvanized or electroplated have been completed.

(b) Except as stated in Section 22.5.31(d), sprayed metal on the parent material shall be kept at least 15 mm, but not more than 300 mm, clear of areas which are to be welded. The restricted area shall be masked during metal spraying.

(c) Except as stated in Section 22.5.31(d), successive coats of paint on the

parent material shall be stepped back at 30 mm intervals commencing at 100 mm from welded joints and at 10 mm from the perimeter of HSFG bolted joints.

(d) If the parent metal in the welding procedure reviewed without objection by the

Project Manager is coated with the pre-fabrication primer or sprayed metal such coatings are permitted to cover the area to be welded. After welding the pre-fabrication primer or sprayed metal adjacent to the weld shall be made good.

(e) The parent material, joint material, exposed parts of bolts, nuts and washers,

welds and weld affected areas shall be cleaned, prepared and brought up to the same protective system as the adjoining surfaces not more than 14 days after the joints have been made.

22.5.32 Sealing of Joints in Steelwork

(a) The different parts of joints in steelwork shall be dry immediately before the joints are assembled.

(b) Gaps around the perimeter of bolted joints and load indicator gaps of HSFG

bolts in steelwork painted overall shall be sealed by brush application of the same painting system as the parent material; gaps shall be plugged if necessary with soft solder wire without flux core as a backing before sealing with paint.

22.5.33 Protection of Hollow Steel Sections

The ends of hollow steel sections shall be sealed by welding mild steel plates, at least 2mm thick, over the open ends. Immediately before hollow steel sections are sealed, porous bags containing anhydrous silica gel shall be inserted in each void at the rate of 0.25 kg/m³ of void.

22.5.34 Protection of Bearing Surfaces for Bridge Bearings

Dirt, oil, grease, rust and mill scale shall be removed from the metal bearing surfaces for bridge bearings. The surfaces shall be masked with tape and shall not be primed or painted until the bonding agent has been applied.


22.5.35 Protection of Uncoated Steelwork Surfaces

The coated surfaces of steelwork coated over part of the surface shall be protected from rust which may form on the uncoated surfaces. Temporary coatings which may affect the bond between concrete and uncoated surfaces against which the concrete is to be placed shall be removed and the uncoated surfaces shall be cleaned before the concrete is placed. The full coating system shall extend 25 mm, or 75 mm for steel piles, into areas against which concrete is to be placed.

22.5.36 Temporary Supports and Fastenings to Steelwork

(a) Steelwork shall be secured in position by temporary supports and fastenings until sufficient permanent connections are complete to withstand the loadings liable to be encountered during erection. The temporary supports and fastenings shall be capable of withstanding loadings which may be encountered during erection and shall not damage the steelwork or the protective coatings.

(b) Riveted and bolted connections shall be aligned using drifts complying with BS 5400:Part 6, Clause 4.12 and shall be temporarily fastened using service bolts.

(c) The Contractor shall design and fabricate all temporary attachments for use

as assembly and erection aids to ensure their use will not damage the structure of its surface protection.

22.5.37 Falsework

Falsework shall be designed, constructed and dismantled in accordance with BS 5975.

22.5.38 Alignment of Steelwork

(a) Steelwork shall be erected in such a manner that the alignment and levels of the steelwork comply with the tolerances stated in Section 22.5.49. The Contractor shall make allowance for the effects of temperature on the steelwork.

(b) Measures shall be taken to ensure that the steelwork will remain stable before

temporary supports and fastenings are slackened or removed for lining, levelling, plumbing or other purposes. The temporary supports and fastenings shall be re-tightened or replaced as soon as the adjustments are complete and at the end of each continuous period of working.

(c) Permanent connections shall be made as soon as a sufficient portion of the

steelwork has been lined, levelled and plumbed. Temporary supports and fastenings shall be replaced by permanent connections progressively and in such a manner that the parts connected are securely restrained in the aligned position at all times.


22.5.39 Foundation Bolts for Steelwork

(a) Foundation bolts for steelwork shall be held firmly in the set position during fixing. Measures shall be taken to ensure that the full movement tolerances are achieved and the bolts are not displaced during concreting. Bolts and nuts, including the threads, shall be protected against damage, corrosion and contamination.

(b) Bolt pockets shall be kept dry and clean. Tubes which are cast in concrete for

grouting bolt pockets shall be securely fixed and sealed to prevent ingress of grout during concreting.

(c) Bolts in bolt pockets shall be installed to allow the bolt movement inside the

pocket as designed without hindrance. 22.5.40 Supporting Devices for Steelwork

The material, size, position and cover of packs, shims and other supporting devices for steelwork which are to be embedded shall be as reviewed without objection by the Project Manager.

22.5.41 Bedding and Grouting of Column Bases

(a) Column bases for each portion of steelwork shall not be bedded or grouted

until the portion has been lined, levelled, plumbed and permanently connected. Spaces below the steel shall be dry, clean and free from rust immediately before bedding or grouting.

(b) Proprietary types of grout shall be used in accordance with the manufacturer's

recommendations. (c) Temporary timber wedges holding steel columns in position shall not project

into pocket bases by more than one-third of the embedded length of the steel column. The pocket shall be initially concreted up to the underside of the wedges and the steel column shall be left undisturbed until 48 hours after concreting; the wedges shall then be removed and the remainder of the pocket shall be concreted.

22.5.42 Sliding Surfaces

Sliding surfaces of uncoated expansion joints shall be treated with molybdenum disulphide grease before making the connection.

22.5.43 Thermal Cutting

Thermal cutting equipment shall not be used on Site unless reviewed without objection by the Project Manager.

22.5.44 Erectors

The Contractor shall carry out all work by trained and experienced erectors. The Contractor shall submit to the Project Manager for review without objection evidence of the erector’s competence.


22.5.45 Safety

The Contractor shall not carry out complex operations at height except from safe platforms large enough to support operators and equipments. Platforms and safe access shall be maintained until work has been completed.

22.5.46 Stability

Stability of structures shall be checked by calculations submitted to the Project Manager for review without objection. The design criteria assumed in the calculations shall be maintained at all stages of construction.

22.5.47 Tolerances: Fabrication of Steelwork

(a) Unless otherwise stated in the Contract, steelwork shall be fabricated to within the tolerances stated in Sections 22.5.47(b) to (i).

(b) Steelwork shall be fabricated to an accuracy that will enable erection within

the specified limits to take place without inducing excessive stresses, deflection or distortion into the structure.

(c) Built-up members, including castellated beams shall comply with BS

5950:Part 2. (d) The length of members with both ends prepared for contact bearing shall not

deviate from the detailed length by more than 1 mm. (e) The length of members without ends prepared for contact bearing, which are

to be framed to other steel parts of the structure, shall not deviate from the detailed length by more than 2 mm for members 10 m or less in length, and 4 mm for members greater than 10 m in length.

(f) The deviation of a member from a straight line drawn between adjacent points

of subsequent effective lateral restraint shall not exceed the greater of 3 mm or 0.1% of the distance between restraints.

(g) The deviation from the specified or proposed camber shall not exceed the

greater of 12 mm or 0.1% of the length of the member. (h) The gaps in joints which depend on contact bearing when assembled during

fabrication shall not exceed 0.75 mm. (i) Fabrication tolerances shall comply with the following British Standards:

(i) BS 5400:Part 6 for plates and sections in bridgework;

(ii) BS 5950:Part 2 for hot rolled sections in building; and

(iii) BS 5950:Part 7 for cold rolled sections in building.

22.5.48 Tolerances: Foundation Bolts

The position of cast-in foundation bolts at the top of base plates shall be within 3 mm of the specified position. The position of foundation bolts in bolt pockets at the top of base plates shall be within 5 mm of the specified position. The line of bolts shall not be tilted from the specified line by more than 1 in 40.


22.5.49 Tolerances: Erection of Steelwork

(a) Unless otherwise stated in the Contract, steelwork shall be erected to within the tolerances stated in Sections 22.5.49(b) to (j) after lining, levelling, plumbing and making the permanent connections.

(b) The position in plan of vertical components at the base shall be within 10 mm of the specified position along either principle setting out axis.

(c) The level of the top of base plates and the level of the lower end of vertical or

raking components in a pocket base shall be within 10 mm of the specified level.

(d) The thickness of bedding shall be within one-third of the nominal thickness or 10 mm, whichever is less, of the specified nominal thickness.

(e) The line of vertical or raking components other than in portal frames shall be

within 1 in 600 and within 5 mm of the specified line in every direction. (f) The line of vertical or raking components in portal frames shall be within 1 in

600 and within 5 mm of the specified line in every direction. (g) The position and level of components connected with other components shall

be within 5 mm of the specified position and level relative to the other components at the point of connection.

(h) The position of components supported on a bearing shall be within 5 mm of

the specified position relative to the bearing along both principal axis of the bearing.

(i) The difference in level between adjacent sloping or horizontal components

connected by a deck slab shall be within 10 mm of the specified difference in level.

(j) Gaps in joints which depend on contact bearing after alignment shall not

exceed 0.75 mm.

22.5.50 Cast-in components (a) Welding of any attachment to cast-in components shall not take place less

than 7 days after casting of the concrete. Where welding is requested to a cast-in item, the Contractor shall demonstrate that the heat generated at the interface with the concrete will not have a detrimental effect on the mechanical properties of the concrete and will not compromise the capacity of the cast-in detail.

(b) Where part of a cast-in component is required to have corrosion protection,

the full protection system shall be applied for an overlap of not less than 50mm extending into the concrete encased zone.

(c) For cast-in fixings designed by the Contractor, the Contractor shall design and

install reinforcement which shall be additional to that shown on the Employer’s Drawings and capable of transmitting the fixing imposed loads into the structure without adversely affecting the structural integrity of the surrounding concrete.


22.6 INSPECTION TESTING AND COMMISSIONING 22.6.1 Procedure Trials for Welding, Flame Cutting and Shearing

(a) If the proposed welding procedure submitted as stated in Section 22.4.5 or the proposed stud welding, flame cutting or shearing procedure for steelwork complying with BS 5400:Part 6 submitted as stated in Section 22.4.6 has not complied with the procedure trial requirements for the procedure stated in the Contract in previous tests, a procedure trial shall be carried out as stated in Sections 22.6.1 (b) to (h).

(b) Procedure trials for welding for structural steel shall comply with

BS 5400:Part 6, Clauses 4.7.3, 5.4.1.1 and 5.4.1.2. (c) Procedure trials for welding for steel castings shall comply with

BS 5400:Part 6, Clauses 4.7.3 and 5.4.2. (d) Procedure trials for welding of studs shall comply with BS 5400:Part 6,

Clauses 4.7.4 and 5.4.4. (e) Procedure trials for flame cutting and shearing shall comply with

BS 5400:Part 6, Clauses 4.7.3 and 5.4.3. (f) Welds for grade A steels complying with BS 4360 are not required to comply

with the requirements for Charpy V-notch impact tests. The temperature of -20°C stated in BS 5400:Part 6, Clause 5.4.1.2(a)(3) shall be amended to 0°C.

(g) If in a welding procedure one or more of the parts to be welded is coated with

a prefabrication primer or metal coating before welding, the same primer or coating shall be applied to the sample before the procedure trial for the welding procedure is carried out.

(h) The thickness of the sample of material to be used in procedure trials for

flame cutting shall be:

(i) 20 mm for material not exceeding 20 mm thick;

(ii) 40 mm for material exceeding 20 mm and not exceeding 40 mm thick; and

(iii) T mm for material exceeding (T-10) mm and not exceeding T mm thick,

where T is any multiple of 10 from 50 up. 22.6.2 Inspection of Procedure Trials for Welding, Flame Cutting and Shearing

Procedure trials for welding, flame cutting and shearing shall be carried out in the presence of an independent HOKLAS accredited inspecting authority.

22.6.3 Results of Procedure Trials for Welding, Flame Cutting and Shearing

If a procedure trial for welding, flame cutting or shearing does not comply with the specified requirements for the procedure trial, the cause of failure shall be established by the Contractor and particulars of proposed changes shall be submitted to the Project Manager for review without objection. Further procedure trials shall be carried out to establish the amended procedure.


22.6.4 Acceptable Procedures for Welding, Flame Cutting and shearing (a) A welding, flame cutting or shearing procedure which complies with the

specified requirements for the procedure trial is defined as an "Acceptable Procedure".

(b) If a procedure trial is not required, the procedure for welding, flame cutting or

shearing submitted as stated in Sections 22.4.5 and 22.4.6 shall become an "Acceptable Procedure".

22.6.5 Commencement of Welding, Flame Cutting and Shearing

Welding, flame cutting or shearing shall not commence until the procedure has been reviewed without objection by the Project Manager.

22.6.6 Changes in Procedures for Welding, Flame Cutting and Shearing

"Acceptable Procedures" for welding, flame cutting or shearing shall not be changed. Further procedure trials shall be carried out to demonstrate proposed changes to the procedure.

22.6.7 Records of Procedure Trials for Welding, Flame Cutting and Shearing

(a) A record of the approval test for welding procedures shall be submitted to the Project Manager for review without objection. The record shall be in the form stated in BS 4870:Part 1, Appendix B or BS 4570, Appendix A as appropriate and shall be endorsed by the independent HOKLAS accredited inspecting authority.

(b) Reports of procedure trials for stud welding, fl ame cutting and shearing shall

be submitted to the Project Manager for review without objection. 22.6.8 Painting Trials

(a) A painting trial shall be carried out for each painting system which will be applied to areas exceeding 10 m2 to demonstrate that the proposed materials and methods of application will produce a painted surface which complies with the specified requirements.

(b) Painting trials shall be carried out at the place where painting to the

Permanent Works will be carried out and using the labour and equipment which will be used to carry out painting to the Permanent Works.

(c) Painting trials shall be carried out on steel cleaned in accordance with the

requirements of the Contract. 22.6.9 Results of Painting Trials

The painted surface produced in a painting trial shall be tested in accordance with BS 3900 and in the event that the test piece does not comply with the specified requirements for the paintwork, the cause of failure shall be established by the Contractor and particulars of proposed changes shall be submitted to the Project Manager for review without objection. Proposed changes to the paint formulation, other than an adjustment in the amount of thinners, shall be carried out at the paint manufacturer's works before the final painting trial and before the first batch of paint is delivered.


22.6.10 Commencement of Painting

Painting shall not commence until the painted surface produced in painting trials complies with the specified requirements for paintwork.

22.6.11 Changes in Materials and Methods of Application for Painting

The materials and methods of application used in a painting trial which complies with the specified requirements shall not be changed.

22.6.12 Inspection of Fabricated Steelwork

(a) Fabricated steelwork shall not be:

(i) covered with protective coatings, concrete or other materials;

(ii) erected; or

(iii) dispatched from the place of fabrication if fabricated off Site, until the steelwork, complies with the specified test and inspection requirements and has been reviewed without objection by the Project Manager.

22.6.13 Independent Testing Consultant

Tests which are stated in this section to be carried out by an independent testing consultant shall be carried out by a HOKLAS accredited testing consultant reviewed without objection by the Project Manager.

22.6.14 Testing: Tests on Steelwork at Manufacturer's Works

(a) Tests shall be carried out on structural steel in accordance with BS 5400:Part 6, Clauses 5.2.1, 5.2.2 and 5.3.

(b) Tests shall be carried out on bolts, nuts and washers in accordance with

BS 3692, BS 4190, BS 4395:Part 1, BS 4395:Part 2 or BS 4933 as appropriate; the tests shall be carried out on full size bolts. The rates of sampling and testing shall be in accordance with BS 4395:Part 1.

(c) The tests shall be carried out by the manufacturer at the manufacturer's works

on samples selected by the Project Manager if the manufacturer's works are in Hong Kong and on samples selected by the independent testing consultant reviewed without objection by the Project Manager if the manufacturer's works are not in Hong Kong.

22.6.15 Batch: Steelwork

(a) A batch of steelwork is the amount of steelwork which is completed or delivered to Site at any one time.

(b) The Contractor shall submit to the Project Manager for review without

objection a list of the components included in each batch at least 7 days before testing starts.


22.6.16 Samples: Steelwork

(a) Samples to be tested shall be selected by the Project Manager if testing is to be carried out in Hong Kong and shall be selected by the independent testing consultant if testing is not to be carried out in Hong Kong.

(b) Samples shall be selected from positions which, in the opinion of the Project

Manager or the independent testing consultant, are representative of the batch as a whole.

(c) The Project Manager will inform the Contractor of the samples selected for

testing at least 3 days before testing is programmed to commence. 22.6.17 Testing: Steelwork

(a) The relevant tests stated in Sections 22.6.21 to 22.6.24 shall be carried out on each batch of steelwork.

(b) The Contractor shall notify the Project Manager at least 7 days before tests in

Hong Kong are carried out. 22.6.18 Reports of Tests on Steelwork

(a) Records of tests on steelwork and a report shall be submitted to the Project Manager for review without objection at least 7 days before the Project Manager's notification of no objection is required. The report shall contain the following details:

(i) procedure under which the testing took place and the exact test location

in the steelwork;

(ii) results of tests compared to the required values, with any non-complying results highlighted;

(iii) any tearing, cracking or other defects; and

(iv) conclusion as to the overall acceptability of the parts of steelwork

examined by the testing consultant.

(b) Reports shall be certified by the Contractor and by the independent testing consultant, who carried out the tests.

22.6.19 Non-compliance: Steelwork

(a) If the result of any test on steelwork stated in Sections 22.6.21 to 22.6.24 does not comply with the Specification for the test, the test shall be carried out on additional samples from the batch. The number of additional tests shall be twice the number of original tests.

(b) If the result of every additional test complies with the Specification, the part of

the batch on which the original tests were carried out shall be considered as complying with the specified requirements for the test.

(c) The batch shall be considered as not complying with the Specification if the

result of any additional test does not comply with the Specification for the test.


22.6.20 Samples: Steel

Samples of steel shall be provided from each batch of steel within 3 days after delivery of the batch to the fabricator's works or to Site. The rate of sampling and the position and direction of the samples shall be in accordance with BS 4360.

22.6.21 Testing: Steel

(a) The tensile test and the impact test shall be carried out on each sample of

steel. The method of testing shall be in accordance with BS 4360. (b) Where stated in the Contract the material shall be subject to the following

additional tests :

(i) ultrasonic grading in accordance with BS 5996, Grade 4; and (ii) through thickness tensile tests to BS 6780, Level Z25.

(c) Quality grading of structural steel shall be carried out on steel which has not

been tested for quality grades by the manufacturer. Quality grading shall be carried out in accordance with BS 5400:Part 6, Clause 3.1.4 or BS 5950:Part 2, Clause 2.1.6 as appropriate.

(d) Testing and quality grading shall be carried out by the independent testing

consultant. 22.6.22 Testing: Welds

(a) Examination and testing of welds shall be carried out after post-weld heat treatment and before the application of corrosion protective coatings. De-burring, dressing, grinding, machining and peening shall be carried out after the visual inspection for cracks, surface pores and joint fit-up and before other inspections and tests are carried out.

(b) Where the Specification requires that butt welds are subject to non-destructive

examination, the following shall apply:

(i) visual inspection in accordance with BS 5289;

(ii) penetrant test in accordance with BS 6443 or magnetic particle test in accordance with BS 6072;

(iii) ultrasonic examination to BS 3923 : Part 1, Part 2; and

(iv) radiographic examination to BS 2600:Part 1, Part 2 or BS 2910.

(c) Where the Specification requires that fillet welds are subject to the non-

destructive examinations, the following shall apply:

(i) visual inspection in accordance with BS 5289;

(ii) penetrant test in accordance with BS 6443 or magnetic particle test in accordance with BS 6072; and

(iii) for welds with a leg length equal to or greater than 12 mm ultrasonic

examination to BS 3923:Part 1.


(d) Welds subject to visual examination shall satisfy the following criteria:

(i) no evidence of cracks, spattering, inclusions, tears or lack of fusion;

(ii) weld sizes and lengths shall not be less than those dimensions specified in the Specification;

(iii) any undercut shall be intermittent and not greater than 0.5 mm deep;

(iv) full penetration shall be achieved unless otherwise specified in the Contract. For connections welded from one side only, any lack of penetration shall be intermittent and not greater than 1.5 mm deep;

(v) root gap in fillet welds shall not exceed 1.0 mm and shall only exceed

0.5 mm intermittently;

(vi) excess penetration shall not exceed 3 mm;

(vii) weld reinforcement shall blend smoothly with the parent metal with no signs of overlap; and

(viii) linear misalignment shall not exceed t/10 where t is the thickness of the

thinner part or 3 mm, whichever is the lesser.

(e) Welds subject to ultrasonic examination shall satisfy the following criteria:

(i) the weld shall have no reflectors which could be interpreted as planar defects such as cracks, tears, lack of fusion or lack of penetration. A planar defect is any flaw whose thickness is less than 25% of its width. In the case of partial penetration welds, the nominated unfused thickness shall not be subject to rejection. The amount of unfused thickness shall be measured and recorded and shall not exceed the nominated width;

(ii) all volumetric defects, where the thickness is equal to or greater than

25% of its width, shall be sized and the weld rejected if:

• the width exceeds 6 mm or T/6, which ever is the lesser; or • where the width exceeds 1.5 mm, but is less than 6 mm or T/6

whichever is lesser, the length exceeds 20 mm (T equals the plate thickness in mm);

(iii) two adjacent defects, if not separated by at least twice the length of the

longer defect, shall be regarded as one continuous defect; and

(iv) a defect shall not begin at a distance less than twice its own length from the end of the weld.

(f) Welds subject to magnetic particle or penetrant examination shall satisfy the following criteria :

(i) the weld shall have no cracks, tears, or lack of fusion;

(ii) any undercut shall be intermittent and not greater than 0.5 mm deep;

(iii) the sum of diameters of piping or porosity shall not exceed 10 mm in

any linear 25 mm of weld and 20 mm in any 300 mm length of weld;


(iv) maximum length of a single defect shall be less than 2/3 of the effective throat of the weld up to a maximum of 20 mm;

(v) the defect shall be further than three times the larger of its own width or

length from the end of the weld or from an adjacent defect;

(vi) any indication which is believed to be spurious shall be regarded as a defect unless on re-evaluation by the same method or by an alternative technique subsequent to surface dressing the indication has been removed; and

(vii) any defects which appear to be subsurface shall be exposed by surface

grinding to display their nature, full size, and shape.

(g) The frequency of weld examination shall be in accordance with requirements in PNAP 160 or the following, whichever is the greater.

(i) all welds shall be visually inspected; and

(ii) for non-destructive examination the frequency shall be as follows :

• full penetration butt welds: - 100% ultrasonic; and - 100% magnetic particle or penetrant inspection;

• partial penetration butt welds and fillet welds with leg length equal to or greater than 12 mm: - 20% minimum ultrasonic; and - 20% minimum magnetic particle or penetrant inspection; and

• Fillet welds with leg length less than 12 mm: - 10% minimum magnetic particle or penetrant inspection.

(h) Testing of stud welding shall be as follows :

(i) all stud welds shall be visually inspected;

(ii) any stud weld which does not exhibit full 360 degree "flash" shall be

subjected to a 15 degree bend test at locations to be reviewed without objection by the Project Manager. Under this test the weld is to show no visible signs of cracking;

(iii) a minimum of 5% of studs which have satisfied the visual inspection

shall be subject to a 15 degree bend test at locations to be reviewed without objection by the Project Manager. Under this test the weld shall show no visible signs of cracking;

(iv) where the bend test reveals an unsatisfactory stud weld, an additional

stud on each side of the defective stud shall be tested; and

(v) all defective studs shall be replaced and re-tested.

(i) Testing of welds shall be carried out by the independent testing consultant. (j) Records of weld testing shall be on HOKLAS endorsed certificates and shall

be submitted to the Project Manager for review without objection in a form suitable for submission to the Buildings Department.


22.6.23 Testing: Fabrication Tolerances

(a) Rolled and built-up sections of steelwork complying with BS 5400:Part 6 shall be tested to determine compliance with fabrication tolerances in accordance with BS 5400:Part 6, Clauses 5.6.1 to 5.6.6.

22.6.24 Testing: Repairs

Defects which have been repaired and adjoining areas which in the opinion of the Project Manager may have been affected by the repair shall be retested.

Materials & Workmanship Specification 1/18 January 2011 Issue No. 5, Volume 1 – Civil & Structural Works Section 23 - Bridgeworks

SECTION 23 BRIDGEWORKS

23.1 GENERAL 23.1.1 Movement Joints Formed in Place

Movement joints formed in place shall comply with Section 20 except as stated in this Section.

23.2 DEFINITIONS AND ABBREVIATIONS 23.2.1 Schedule of Bearings

Schedule of bearings is the schedule of bearings stated in the Contract. 23.2.2 Type of Bridge Bearing

“Type of bridge bearing” is a term used to identify bridge bearings of exactly the same design and same capacity for all bearing loads, movements and rotations.

23.2.3 Batch: Bridge Bearings

A batch of bridge bearings is any quantity of bridge bearings of the same type fabricated by the same manufacturer and which for the purpose of testing elastomeric bearings contains the same type of elastomer.

23.2.4 Fabricated Movement Joint

Fabricated movement joint is a manufactured assembly, including nosings, designed to carry traffic smoothly over a movement joint and to seal the joint against the ingress of water and debris.

23.2.5 Movement Joint Movement joint is a permanent joint or hinge throat which allows expansion, contraction or angular rotation to occur.

23.2.6 Movement Joint Formed in Place Movement joint formed in place is a movement joint formed during construction of a structure to permit adjacent structural elements to move relative to each other without damage.

23.3 DESIGN AND PERFORMANCE CRITERIA 23.3.1 Design of Bridge Bearings

(a) Bridge bearings shall be designed by the Contractor unless otherwise stated in the Contract.


(b) The design and manufacture of bridge bearings and the materials used shall comply with BS 5400:Part 9, including the guidance notes, except as stated in Clauses 23.3.2 and 23.3.3. Inspection and maintenance of bridge bearings shall be easy to carry out and the bearings shall be easily replaceable.

(c) The maximum bearing stress in concrete underlying or overlying a bridge

bearing under the design load at the ultimate limit state shall not exceed 40% of the specified grade strength of the concrete. Higher bearing stresses may be adopted provided that sufficient steel reinforcement is provided to resist the resulting bursting forces and that the bearing stresses are within the limits stated in Clause 7.2.3.3 of BS 5400:Part 4.

(d) The deflection of bridge bearings which have a specified zero horizontal

movement in a particular direction shall not exceed 1 mm in that direction under the maximum horizontal loadings

23.3.2 Design of Sliding Bearings

(a) Clause 4.3.4.2 of BS 5400:Part 9:Section 9.2 shall not apply to sliding bearings.

(b) Stainless steel sliding surfaces of sliding bearings which are attached to

backing plates by mechanical fasteners instead of continuous welding along the edges shall be bonded to the backing over the full area and supplemented with peripheral sealing if necessary. Mechanical fixing by peripheral sealing only shall not be used.

(c) The design of sliding bearings shall prevent sliding surfaces becoming

contaminated with dirt that would increase the friction coefficient and increase the rate of wear.

23.3.3 Design of Elastomeric Bearings

The requirements for use of elastomer in elastomeric bearings at subzero temperatures stated in Clause 3.7.1 of BS 5400:Part 9:Section 9.2 shall not apply.

23.3.4 Design of Guides for Bridge Bearings

The clearance between guides and complementary sliding surfaces of a guided bearing shall not exceed 1 mm.

23.3.5 Design of Fixings for Bridge Bearings

(a) Except for elastomeric bearings, bridge bearings, including bearings which are not required to provide horizontal restraint, shall be fixed to the superstructure and substructure with mechanical fixings or by other methods reviewed without objection by the Project Manager. The Contractor may propose to use friction between the bearing and the superstructure or substructure to resist the horizontal forces provided he shall apply a factor of safety of at least 2 to the proven coefficient of friction and that the worst combination of vertical load and horizontal load is considered.

(b) The ultimate capacity of the mechanical fixings for bridge bearings shall not be

less than the worst combination of loading at ultimate limit state stated in the schedule of bearings.


23.3.6 Design of Fabricated Movement Joints

(a) Fabricated movement joints shall be a proprietary type reviewed without objection by the Project Manager.

(b) Fabricated movement joints shall be capable of withstanding the following

loads, either separately or in combination:

(i) vertically: two 112.5 kN wheel loads, 1 m apart, each spread over a contact area giving an average pressure of 1 MPa and applied in such a manner as to produce the worst possible effect; and

(ii) horizontally: a traction force of 75 kN/m run of the joint applied perpendicular to the alignment of the joint, together with any forces arising from strain of the joint.

Allowance for additional loading due to impact is not necessary.

(c) Fabricated movement joints shall accommodate the movements and rotations stated in the Specification without damaging the joint and without loading the supporting structure with forces which arise from strain of the joint exceeding 5 kN/m run of the joint.

(d) Fabricated movement joints shall either be watertight or provided with a

drainage layer or channel to collect water passing through the joint and to divert the water away from the underlying structure.

(e) Fabricated movement joints shall provide easy clearance of grit or silt entering

slots, grooves or channels forming or associated with the joint. (f) Surfaces of fabricated movement joints which will be exposed at finished road

level shall provide a resistance to skidding not less than that of the adjacent road surface.

(g) Fabricated movement joints shall not impair the riding quality of the road

surface for vehicular traffic and the passage of vehicular traffic shall not cause undue noise or vibration. The size of gaps, including gaps sealed with flexible material, on the riding surface of the joint shall not exceed 65 mm.

(h) The passage of pedestrians and cyclists shall not be impeded or endangered

by fabricated movement joints. 23.3.7 Design of Fixings for Fabricated Movement Joints

(a) The holding down and fixing arrangements for fabricated movement joints shall be capable of withstanding the loads stated in Clause 23.3.6(b). The diameter of bolts fixed as double row bolts on one side shall be at least 12 mm and the diameter of other holding down bolts and studs shall be at least 16 mm.

(b) Fixings for fabricated movement joints shall be compatible with the

reinforcement in the underlying concrete. Any revisions to the reinforcement required to suit the fixings shall be designed by the Contractor and submitted to the Project Manager for review without objection.


23.4 MATERIALS 23.4.1 Prefabricated Sheeting

(a) Prefabricated sheeting for waterproofing shall be a proprietary type reviewed without objection by the Project Manager.

(b) Prefabricated sheeting shall not rot or support the growth of mildew and shall

be compatible with the materials with which it is in contact. Prefabricated sheeting which will be exposed to sunlight after installation shall be of a type unaffected by ultraviolet light.

(c) Prefabricated sheeting shall have a tensile strength, pliability and puncture

resistance such that the sheeting will withstand the stresses induced during handling and laying without damage. The elongation properties of prefabricated sheeting shall be such that the sheeting can accommodate the creep, shrinkage and thermal movements of concrete without distress.

(d) Prefabricated bituminous sheeting shall be a self-adhesive, self-sealing type

and shall have a thickness of at least 1.2 mm. (e) Prefabricated rubberised base sheeting shall be of a type which is unaffected

by fuels, oils or grease. (f) Primers and mastic for prefabricated sheeting shall be a proprietary type

recommended by the sheeting manufacturer and reviewed without objection by the Project Manager.

23.4.2 Bentonite Panels

(a) Bentonite panels shall consist of bentonite filler enclosed in self-degradable boards. The panels shall have a permeability of less than 1 x 10-7mm/sec under simulated test conditions similar to those of the as-built conditions. The performance of bentonite panels shall not be affected by contaminants present in the groundwater.

(b) Bentonite panels for slabs less than 200 mm thick or with soil cover of less

than 450 mm shall be special panels with specific provision for swelling to prevent lifting of the slab.

(c) Bentonite joint seal and bentonite granules shall be a proprietary type

recommended by the bentonite panel manufacturer and reviewed without objection by the Project Manager.

(d) Polyethylene sheeting for use with bentonite panels shall be a heavy duty

type.

23.4.3 Delivery of Bentonite Panels

Bentonite panels shall be delivered in original unbroken packages bearing the manufacturer's label.


23.4.4 Storage of Materials for Waterproofing Systems

(a) Prefabricated sheeting and bentonite panels shall be stored in accordance with the manufacturers' recommendations in a dry weatherproof store with a raised floor.

(b) Bituminous paint shall be stored in sealed containers marked to identify the

contents and protected from exposure to conditions which may affect the bituminous paint. The bituminous paint shall be stored in accordance with the manufacturer's recommendations and shall not be used after the recommended shelf life has been exceeded.

23.4.5 Bituminous Paint

Bituminous paint for waterproofing shall be cut-back bitumen complying with BS 3690:Part 1. The bitumen shall have a viscosity grade as determined by a standard tar viscometer within the range 25 - 50 seconds with a coverage of 0.5 L/m2. Primers for bituminous paint shall be a proprietary type recommended by the bituminous paint manufacturer and reviewed without objection by the Project Manager.

23.4.6 Holding Down Bolts for Bridge Bearings

Holding down bolts for bridge bearings shall be a proprietary type reviewed without objection by the Project Manager.

23.4.7 Cement Mortar, Grout and Adhesive for Bridge Bearings

(a) Cement mortar for bedding and construction of unreinforced plinths for bridge bearings shall be a proprietary non-shrink type with a grade strength of at least 50 MPa reviewed without objection by the Project Manager.

(b) Chemical-resin mortar for the construction of plinths for bridge bearings shall

be a proprietary non-shrink type with a grade strength of at least 50 MPa reviewed without objection by the Project Manager.

(c) Grout for grouting base plates and holding down bolts shall be a proprietary

non-shrink cementitious type with a grade strength of at least 50 MPa reviewed without objection by the Project Manager. The grout shall readily flow under base plates and shall not bleed or segregate. The suitability of the grout shall be demonstrated by Site trials and reviewed without objection by the Project Manager.

(d) Adhesives and chemical resin mortars for locating and bedding elastomeric

bridge bearings shall be a proprietary type reviewed without objection by the Project Manager. They shall be compatible with the elastomer.

23.4.8 Dowel Bars for Bridge Bearings

Dowel bars for bridge bearings shall be Grade 316 S 31 or 316 S 33 stainless steel complying with BS 970:Part 1.


23.4.9 Protective Coatings to Bridge Bearings

Metal components of bridge bearings shall be protected against corrosion by a protective coating complying with, and selected in accordance with, BS 5493. For the purpose of selecting the coating system, the environment shall be classified as 'exterior exposed - polluted coastal' and the typical time to first maintenance shall be 'very long' (20 years or more).

23.4.10 Marking of Bridge Bearings

(a) Bridge bearings shall be marked by the manufacturer either with the type numbers stated in the schedule of bearings or with the manufacturer's own type or other numbers. A schedule shall be provided which relates the manufacturer's own type or other numbers to the type numbers stated in the schedule of bearings.

(b) The design movement directions and magnitudes and the axes of bearing

shall be marked on the upper faces of bridge bearings to facilitate checking of the installation. Movement indicators shall be provided for sliding and roller bearings to permit checking of movements of the bearings before and after installation.

23.4.11 Vehicular Parapets

(a) Vehicular parapets shall be of the types stated in the Contract. (b) Steel for vehicular parapets, including welding, shall comply with Section 18

except that the requirements for testing shall not apply. (c) Protective treatment to steel for vehicular parapets shall comply with

Section 18 and shall be applied after welding, drilling and cutting is complete. (d) Aluminium for vehicular parapets shall comply with the following: Wrought aluminium and aluminium alloys for general engineering purposes

(i) plate, sheet and strip : BS 1470

(ii) rivet, bolt and screw stock : BS 1473

(iii) bars, extruded round tubes and sections : BS 1474. (e) Aluminium shall be anodised to Grade AA 25 in accordance with BS 1615. (f) Welding of aluminium for vehicular parapets shall comply with the following: (g) TIG welding of aluminium, magnesium and their alloys :

BS 3019:Part 1; and (h) Aluminium and aluminium alloys : BS 3571:Part 1 (i) Stainless steel bolts, nuts and washers for vehicular parapets shall be Grade

A4-80 and shall comply with BS 6105.


23.4.12 Holding Down Bolts for Vehicular Parapets

Holding down bolts for vehicular parapets shall be a proprietary type reviewed without objection by the Project Manager.

23.4.13 Grout for Vehicular Parapets

Grout for holding down bolts for vehicular parapets shall be based on polyester resins and shall be a proprietary type reviewed without objection by the Project Manager.

23.4.14 Joint Filler

Joint filler for movement joints formed in place shall be non-absorbent. 23.4.15 Joint Sealant

(a) Joint sealant for movement joints formed in place shall be a polysulphide-based sealant. Polyurethane-based sealant shall not be used.

(b) Joint sealant shall be resistant to attack by petrol, diesel oil, dilute acids and

alkalis, synthetic and mineral oils, hydraulic fluids and paraffin. The sealant shall have a transverse butt joint movement range for repeated cyclic movement of at least 25% of the width of the joint.

23.4.16 Compression Seals

Compression seals shall be a proprietary type reviewed without objection by the Project Manager and shall be manufactured from natural rubber, neoprene or other synthetic material. Compression seals shall have the dimensions specified by the manufacturer for each joint width.

23.4.17 PVC Capping Strip

PVC capping strip shall be a proprietary type reviewed without objection by the Project Manager.

23.4.18 Holding-down Bolts for Movement Joints

Holding-down bolts for movement joints shall be a proprietary type reviewed without objection by the Project Manager.

23.4.19 Grout for Movement Joints

Grout for holding-down bolts for movement joints shall be based on polyester resins and shall be a proprietary type reviewed without objection by the Project Manager.


23.5 SUBMISSIONS 23.5.1 Particulars of Waterproofing Systems

(a) The following particulars of the proposed waterproofing systems shall be submitted to the Project Manager for review without objection:

(i) manufacturer's literature and a certificate for prefabricated sheeting

showing the manufacturer's name, the date and place of manufacture and showing that the prefabricated sheeting complies with the Specification including results of tests for:

• tensile strength; • pliability; • puncture resistance; and • elongation;

(ii) manufacturer's literature and a certificate for bentonite panels showing

the manufacturer's name, the date and place of manufacture and showing that the bentonite panels comply with the Specification including results of tests for permeability;

(iii) manufacturer's literature and a certificate for bituminous paint showing

the manufacturer's name, the date and place of manufacture and showing that the bituminous paint complies with the Specification including results of tests for viscosity;

(iv) particulars of primers and mastic for prefabricated sheeting, bentonite

joint seal and bentonite granules and primers for bituminous paint; and

(v) methods of laying prefabricated sheeting and bentonite panels.

23.5.2 Representative Samples of Materials for Waterproofing Systems

(a) Representative samples of the following proposed materials for waterproofing systems shall be submitted to the Project Manager for review without objection:

(i) prefabricated sheeting; and

(ii) bentonite panels.

23.5.3 Particulars of Bridge Bearings

(a) The following particulars of the proposed bridge bearings shall be submitted to the Project Manager for review without objection:

(i) details of type of bridge bearings, including materials, and the name and

address of the manufacturer; (ii) design calculations, including calculations of bearing stresses above

and below the bearings and calculations for bursting or other necessary additional or revised reinforcement;

(iii) Contractor’s Drawings of bearings including installation thereof and any

additional or revised reinforcement details;


(iv) a certificate for each type of bridge bearing showing the manufacturer's

name, the date and place of manufacture and showing that the bridge bearings comply with the Specification including results of:

• friction tests; • load tests; • tests on elastomers; • quick production tests; and • stiffness tests;

(v) values of stiffness in compression and in shear of elastomeric bearings; (vi) details of fixings to superstructures and substructures; (vii) details of protective coatings; (viii) methods of installation; and (ix) programme of manufacture, testing and delivery, including name and

address of testing laboratory.

23.5.4 Representative Samples of Materials for Vehicular Parapets

Representative samples of the proposed posts and rails for vehicular parapets shall be submitted to the Project Manager for review without objection.

23.5.5 Particulars of Movement Joints

(a) The following particulars of the proposed movement joints shall be submitted to the Project Manager for review without objection:

(i) details of type of movement joint and the name and address of the

manufacturer;

(ii) design calculations and Contractor’s Drawings;

(iii) details of fixings, including the size, length and spacing of holding down bolts and any necessary revisions to the reinforcement;

(iv) details of materials for making good adjoining road surfaces and

nosings, including reinforcement, jointing and curing details;

(v) programme of manufacture, testing and delivery; and

(vi) for fabricated movement joints, a written undertaking from the Contractor stating that the movement joint supplier shall install the proposed movement joint.


23.6 WORKMANSHIP 23.6.1 Installation of Waterproofing Systems

(a) Surfaces on which waterproofing systems will be laid shall be clean, dry and free from voids, loose aggregate, sharp protrusions, projecting tying wire, release agents and other items or substances which are likely to damage or affect the waterproofing system.

(b) Waterproofing systems shall be laid in accordance with the manufacturer's

recommendations. (c) Before waterproofing systems are laid on concrete surfaces, the concrete

surface shall have been cured for at least 7 days and shall be cleaned with a broom and sealed with one coat of primer. Primed surfaces shall not be covered until the solvent constituent has evaporated. Water shall be allowed to evaporate from primers containing bituminous emulsion before the surface is covered. Primed surfaces shall be protected from contamination

23.6.2 Installation of Prefabricated Sheeting

(a) Prefabricated sheeting shall be laid one sheet at a time from low points and drains, towards high points. The sheeting shall be firmly and tightly brought into contact with the primer or underlying sheeting.

(b) Laps shall be formed at joints between individual sheets of prefabricated

sheeting. End laps shall be at least 150 mm and side laps shall be at least 100 mm. Joints shall be arranged in such a manner that the number of layers of sheeting at any joint does not exceed three.

(c) The perimeter of prefabricated sheeting laid each day shall be sealed with a

trowelled bead of mastic.

(d) A double layer of prefabricated sheeting shall be laid around pipes, posts or other components which pass through the sheeting and the edges shall be sealed with a trowelled bead of mastic.

23.6.3 Installation of Bentonite Panels

(a) Bentonite panels shall not be laid in water or during wet weather. (b) Immediately before bentonite panels are laid on a surface, joints and cracks in

the surface shall be sealed with bentonite joint seal. (c) Polyethylene sheeting shall be laid below and above bentonite panels to

prevent prehydration. Laps of at least 100 mm shall be formed at joints in the sheeting.

(d) Laps shall be formed at the edges of bentonite panels or the edges shall be

closely butted together and the seam filled with loose bentonite granules. (e) Bentonite panels shall not be fixed to the underlying surface unless permitted

by the Project Manager. If permitted, the method of fixing shall be by 25 mm masonry washerhead nails or by other methods reviewed without objection by the Project Manager.


(f) Bentonite panels shall be laid continuously around wall bases and corners. Flat panels shall not be folded or bent if the panels will be damaged or bentonite filler will be lost.

(g) Bentonite which is exposed at the edges of bentonite panels cut to fit around

pipes, posts or other components which pass through the panel shall be taped or sealed by other methods reviewed without objection by the Project Manager to prevent loss of the bentonite filler. The joint between panels and the pipe, post or component shall be sealed with a continuous bentonite seal.

(h) Exposed bentonite panels shall be protected from moisture by polyethylene

sheeting unless panels with a water repellent coating are used. The sheeting shall be removed before fill material is deposited. As soon as practicable after each course of panels has been laid, fill material shall be deposited and compacted up to a level which is within 50 mm of the top edge of the panel.

(i) Damaged or expanded bentonite panels shall be not be used.

23.6.4 Bituminous Paint Waterproofing Systems

Surfaces to which bituminous paint will be applied shall be treated with a primer before the paint is applied if recommended by the paint manufacturer. Bituminous paint shall be applied in two coats; the first coat shall be allowed to dry before the second coat is applied.

23.6.5 Installation of Bridge Bearings

(a) Bridge bearings shall be installed as recommended in BS 5400:Part 9 and as stated in Clauses 23.6.5(b) to (g).

(b) Bridge bearings which have been pre-assembled shall not be dis-assembled. (c) The levels of substructures stated in the Contract on which bridge bearings

will be installed shall be adjusted to suit the thickness of the bearing so that the superstructure will be at the specified level after completion.

(d) Bridge bearings, other than elastomeric bridge bearings, shall be set level on substructures using only a thin layer of cementitious mortar, unless the Project Manager permits the bearings to be set on plinths. If setting on plinths is permitted, the plinths shall be constructed of cementitious mortar or grout, unless otherwise reviewed without objection by the Project Manager, and the thickness of such plinths shall be at least 25 mm and shall not exceed 40 mm. If reviewed without objection by the Project Manager, the plinths may be constructed of chemical resin mortar, having a thickness of at least 5 mm and not exceeding 10 mm.

(e) Elastomeric bearings shall be set directly on the substructure. A thin layer of

cementitious mortar may be used to level the surface if the substructure is concrete. Elastomeric bearings shall not be set in position by grouting between the substructure and the underside of the bearing.

(f) The top surface of bridge bearings which will support precast concrete or other

prefabricated beams shall be covered with a thin layer of cementitious mortar immediately before the beam is placed. The beam shall be temporarily supported on folding wedges until the mortar has achieved sufficient strength to transmit the weight of the beam to the bearings. Thereafter the temporary supports shall be removed.


(g) Temporary locking devices for bridge bearings shall be removed before post-tensioned superstructures are stressed. Temporary locking devices for other types of superstructures shall be removed at times reviewed without objection by the Project Manager.

23.6.6 Tolerances: Bridge Bearings

(a) The centreline of bridge bearings shall be within 3 mm of the specified position.

(b) The level of bridge bearings shall be within 0.0001 times the adjacent span or

the lesser of the adjacent spans or within 5 mm of the specified level, whichever is less.

(c) The inclination of bridge bearings shall be within 1 in 200 of the specified

inclination. (d) The horizontal axis of bridge bearings shall be within 0.005 radian of the

specified alignment. (e) Departure from the common plane between twin or multiple bridge bearings

shall be within the tolerances stated in the Contract. 23.6.7 Installation of Vehicular Parapets

(a) Vehicular parapets shall be installed to a smooth alignment and with the posts vertical.

(b) Grouting shall be carried out by setting the vehicular parapets in position and

grouting the gap between the vehicular parapets and the structure. Vehicular parapets shall be held in position until connections and fixings are complete and until the fixings have gained sufficient strength.

23.6.8 Tolerances: Vehicular Parapets

Vehicular parapets shall be within 10 mm of the specified position and height. 23.6.9 Installation of Fabricated Movement Joints

(a) Fabricated movement joints shall be installed in accordance with the manufacturer's recommendations. The Contractor shall provide that installation of the movement joint shall be carried out by the supplier of the movement joint.

(b) The vertical faces of recesses in bridge decks for fabricated movement joints

shall be formed by saw-cutting. Holding-down bolts shall be cast into the concrete for direct mounting of the joints unless the Project Manager permits the bolts to be grouted. If grouting is permitted, the grouting shall be carried out by setting the movement joint in position and grouting the gap between the movement joint and the structure. Rebates and pockets for subsequent trimming to line and level or for holding-down bolts shall not be used.

(c) The bedding to fabricated movement joints shall be formed such that there

shall be no gaps between the joint and the bedding.


(d) Relative movement between components and supports of a fabricated movement joint shall be prevented during installation of the joint and during placing and hardening of concrete and mortar under the components. Joint components shall be free to move longitudinally relative to each other.

(e) When one side of a fabricated movement joint is being set, the other side shall

be free from longitudinal restraint. Strongbacks or templates used to locate the sides of a joint shall not be fixed to both sides at any one time.

23.6.10 Road Surface Adjoining Fabricated Movement Joints

(a) The gap between fabricated movement joints and the adjoining road surface or nosing shall be made good after installation of the joint with material which has properties as similar as practicable to those of the material in the adjoining road surface.

(b) Bituminous road surfaces shall be made good with a bituminous mixture or

elastomeric concrete. Concrete road surfaces shall be made good with a cementitious matrix reinforced with metal or glass fibres or with elastomeric or polymer concrete. Epoxy resin mortar shall not be used.

(c) Elastomeric and polymer concrete shall be prepared, laid and cured in

accordance with the manufacturer's recommendations. 23.6.11 Protection of Fabricated Movement Joints

(a) The Project Manager shall be notified before Contractor's Equipment or other vehicles cross a fabricated movement joint or the adjacent road surface.

(b) Contractor's Equipment or other vehicles shall not cross fabricated movement

joints or adjacent road surfaces until installation of the joint is complete unless reviewed without objection by the Project Manager. Ramps shall be provided to allow the vehicles to cross without loads being applied to the joint.

23.6.12 Forming Movement Joints

Gaps forming part of movement joints formed in place shall be filled with joint filler fixed in position with adhesive. The edge of the joint filler shall be covered with bond breaker tape or a PVC capping strip.

23.6.13 Forming Grooves

Grooves for joint sealant and compression seals for movement joints formed in place shall be formed by saw cutting.

23.6.14 Sealing Grooves

Grooves for movement joints formed in place shall be sealed with joint sealant or with a compression seal.

23.6.15 Tolerances: Fabricated Movement Joints

The surface of fabricated movement joints shall be at least 1 mm, and not more than 3 mm, below the surrounding road surface.


23.7 INSPECTION TESTING AND COMMISSIOINING 23.7.1 Testing: Bridge Bearings

(a) Bridge bearings shall be tested by the Contractor at a laboratory reviewed

without objection by the Project Manager. (b) The Contractor shall inform the Project Manager of the date and place of

testing at least 28 days before testing starts. (c) The procedures for testing bridge bearings shall be submitted to the Project

Manager for review without objection and thereafter shall not be changed. (d) The reports of tests on bridge bearings shall include load/deflection graphs

and shall be submitted to the Project Manager for review without objection at least 28 days before installation of the bridge bearings is programmed to start.

23.7.2 Samples: Friction Test for Bridge Bearings

One sample of bridge bearing shall be provided from each batch of sliding bearings and from each batch of other types of bridge bearings which contain sliding parts.

23.7.3 Testing: Friction Test for Bridge Bearings

(a) The friction test shall be carried out on each sample of bridge bearing provided as stated in Clause 23.7.2 to determine the coefficient of friction, flatness, bonding properties and resistance to mechanical damage. The method of testing shall be in accordance with Appendix A23.1.

(b) The friction test shall be carried out at room temperature.

23.7.4 Compliance Criteria: Friction Test for Bridge Bearings

(a) The results of friction tests for bridge bearings shall comply with the following requirements:

(i) the coefficient of friction in any test position shall not exceed 0.04;

(ii) the flatness of the stainless steel shall be within the specified limits

after testing;

(iii) the bond to the backing plate shall be unaffected by the friction test; and

(iv) PTFE shall be free from mechanical damage after testing.

23.7.5 Samples: Bridge Bearings other than Elastomeric Bearings

One sample of bridge bearing shall be provided from each batch of bridge bearings other than elastomeric bearings.


23.7.6 Testing: Bridge Bearings other than Elastomeric Bearings

Vertical load tests and horizontal load tests shall be carried out on each sample of bridge bearing provided as stated in Clause 23.7.5. The test loads shall be the serviceability limit state loads. The method of testing shall be in accordance with Clause 7.2(b)(1) of the guidance notes to BS 5400:Section 9.2.

23.7.7 Compliance criteria: Bridge Bearings other than Elastomeric Bearings

The results of tests on bridge bearings other than elastomeric bearings shall comply with the requirements stated in Clause 7.2(b)(1) of the guidance notes to BS 5400:Section 9.2.

23.7.8 Samples: Elastomeric Bearings

(a) Except as stated in Clause 23.7.8(b), one sample of elastomeric bearing shall be provided from each batch of elastomeric bearings for testing by the "Quick Production Test".

(b) If the Contractor considers there is sufficient evidence that “Quick Production

Tests” have been successfully completed on identical materials in the previous 18 months he may submit the evidence to the Project Manager and propose that the tests are not necessary. The Project Manager will respond within 14 days of the date of receipt of the submission.

(c) Two samples of elastomeric bearings shall be provided from each batch of ten

or part thereof of elastomeric bearings to determine the stiffness in compression and stiffness in shear.

23.7.9 Testing: Elastomeric Bearings

(a) Each sample of elastomeric bearing provided as stated in Clause 23.7.8(a) shall be tested to determine the physical and weathering properties of the elastomer and the bond of the elastomer to metal. The method of testing shall be the "Quick Production Test" in accordance with the guidance notes to BS 5400:Section 9.2.

(b) One sample of elastomeric bearing provided as stated in Clause 23.7.8(c)

shall be tested to determine the stiffness in compression and the other sample shall be tested to determine the stiffness in shear. The method of testing to determine the stiffness in compression shall be in accordance with Clause 7.2(b)(2) of the guidance notes to BS 5400:Section 9.2. The method of testing to determine the stiffness in compression shall be in accordance with BS 5400:Section 9.2, Appendix A.

23.7.10 Compliance Criteria : Elastomeric Bearings

(a) The results of tests on elastomeric bearings shall comply with the following requirements:

(i) Pthere shall be no evidence of surface flaws in the bearings during or

after the test;

(ii) there shall be no irregularities in the deflected shape of laminated bearings during or after the test;


(iii) the stiffness in compression shall be within 20% of the value quoted by the manufacturer and reviewed without objection by the Project Manager; and

(iv) the stiffness in shear shall be within 20% of the value quoted by the

manufacturer and reviewed without objection by the Project Manager.


APPENDIX A23.1

FRICTION TEST FOR BRIDGE BEARINGS A23.1.1 Scope This method covers the determination of the coefficient of friction, flatness, bonding

properties and resistance to mechanical damage of bridge bearings by means of a friction test.

A23.1.2 Equipment (a) The following equipment is required:

(i) compression testing rig;

(ii) test loads;

(iii) equipment for measuring the loads applied, readable and accurate to within 2% of the measured load;

(iv) equipment for measuring movement, readable and accurate to

0.01 mm; and

(v) lubricant of the same type as will be used in service. A23.1.3 Procedure (a) The procedure shall be as follows:

(i) the PTFE surface of the bearing shall be lubricated with the lubricant;

(ii) two sets of sliding surfaces shall be mounted back to back between the platens of the compression testing rig with the stainless steel sliding surfaces in the center;

(iii) a vertical load equal to the permanent load stated in the schedule of

bearings shall be applied for 1 hour;

(iv) a horizontal load shall then be applied steadily and without shock to the pair of stainless steel sliding surfaces and shall be increased at a rate of 0.2% of the vertical load per minute until movement occurs between the sliding surfaces;

(v) the maximum horizontal load sufficient to cause movement of at least

25 mm between the stainless steel and PTFE sliding surfaces at a rate not exceeding 50 mm/min shall be recorded;

(vi) the loads shall be removed; and

(vii) the sliding surfaces shall be removed from the rig and inspected.


A23.1.4 Calculation

(a) The coefficient of friction shall be calculated from the equation: Maximum horizontal force Coefficient of friction = 2 x vertical load



(i) name of bearing manufacturer;

(ii) details of bearing and sliding surfaces;

(iii) the vertical load applied;

(iv) the maximum horizontal force applied;

(v) the total movement and rate of movement at the maximum horizontal force applied;

(vi) the coefficient of friction to two significant figures;

(vii) details of any damage to the sliding surfaces; and

(viii) that the test method used was in accordance with this General


General Materials & Workmanship Specification 1/7 January 2011 Issue No. 5, Volume 1 – Civil & Structural Works Section 24 – Water Retaining Structures

SECTION 24 WATER RETAINING STRUCTURES 24.1 GENERAL

(a) The works and materials specified below shall comply with the sections stated, unless otherwise stated in this Section.

(i) earthworks shall comply with Section 7;

(ii) formwork and finishes to concrete shall comply with Section 18;

(iii) steel reinforcement shall comply with Section 19;

(iv) concrete shall comply with Section 20;

(v) joints in concrete shall comply with Section 20; and

(vi) drainage systems shall comply with Section 6.

24.2 DEFINITIONS AND ABBREVIATIONS 24.2.1 Water Retaining Structure

Water retaining structure is a structure, or part of a structure, including walls, floors, roofs, columns and footings, which is stated in the Contract to be constructed for storing, conveying or excluding water, sewage or other aqueous liquids.

24.3 MATERIALS 24.3.1 Sliding Layers

Sliding layers below floor slabs of water retaining structures shall be a proprietary type of polyethylene sheeting reviewed without objection by the Project Manager. Polyethylene sheeting shall be impermeable and shall have a nominal thickness of 1.1 mm.

24.4 SUBMISSIONS 24.4.1 Particulars of Sliding Layers

Particulars of the source and type of proposed sliding layers for water retaining structures shall be submitted to the Project Manager for review without objection.


24.4.2 Particulars of Materials and Methods of Construction for Water Retaining Structures

(a) The following particulars of the proposed materials and methods of

construction for water retaining structures shall be submitted to the Project Manager for review without objection: (i) sequence and method of concreting bays in floor slabs, walls and roof

slabs and in columns and footings; (ii) details of alternative locations of construction joints if required;

(iii) details of type and size of waterstops at construction joints and box-

outs; (iv) sequence and method of testing roofs for watertightness; and (v) details of method of testing water retaining structures for watertightness

including:

• arrangement of pumps and equipment; • source of water; • equipment for measuring fall in water level; • device for dampening the oscillatory motion of the water surface; • filling rate; and • method of correction for evaporation and rainfall.

24.4.3 Representative Samples of Sliding Layers

Representative samples of the proposed sliding layers for water retaining structures shall be submitted to the Project Manager for review without objection.

24.5 WORKMANSHIP 24.5.1 Drainage Systems

Measures shall be taken to prevent concrete and deleterious material from being deposited in drainage systems under floors and on roofs of water retaining structures. After construction and before testing, the drainage system shall be thoroughly cleaned by rodding and flushing to remove any deleterious material which may impede the flow of water into or through the drainage system. The lines and levels of drainage systems shall be within 20 mm of the specified horizontal alignment and within 10 mm of the specified vertical alignment.

24.5.2 Laying Sliding Layers

Polyethylene sheeting in sliding layers below floor slabs of water retaining structures shall be laid flat without creases. Laps shall be at least 225 mm and there shall be no gaps at the edges of bays.


24.5.3 Floor Slabs of Water Retaining Structures

Except as otherwise stated on the Employer's Drawings, if reinforcement is continuous across the joint between bays in the floor slab of water retaining structures, the bays shall be concreted contiguously, in sequence, with a minimum period of 48 hours between completion of concreting one bay and commencement of concreting the adjacent bay.

24.5.4 Walls of Water Retaining Structures

(a) Except as otherwise stated on the Employer's Drawings, if reinforcement is continuous across the joint between bays in the wall of water retaining structures, the bays shall be concreted contiguously, in sequence, with a minimum period of 72 hours between the completion of concreting the lift in one bay and commencement of concreting the adjacent lift in the adjacent bay.

(b) The first lift in each bay in the walls of water retaining structures shall be

concreted within seven days after completion of concreting the adjacent base of the wall. Individual lifts shall be concreted in one continuous operation without cold joints, whether or not the full height of the wall is concreted in one lift. If the full height of the wall is not placed in one lift, succeeding lifts shall be concreted within seven days from concreting of the adjacent lift.

24.5.5 Roof Slabs of Water Retaining Structures

If reinforcement is continuous across the joint between bays in the roof slab of water retaining structures, the bays shall be concreted contiguously, in sequence, with a minimum period of 48 hours between completion of concreting one bay and commencement of concreting the adjacent bay.

24.5.6 Built-in Pipes in Water Retaining Structures

Unless otherwise stated in the Contract, puddle flanges on built-in pipes in water retaining structures shall be located centrally within the formwork. Waterstops shall be fixed around the perimeter of box-outs to the built-in pipes.

24.5.7 Protection of Water Retaining Structures

(a) Immediately after the roof slab of water retaining structures has been tested, the slab shall be protected with damp sacks or by other methods reviewed without objection by the Project Manager from exposure to conditions which may affect the slab; the protection shall be continued until the roof drainage system has been constructed or the fill material has been deposited and compacted.

(b) Materials shall not be stockpiled on roof slabs of water retaining structures.

Contractor's Equipment or other vehicles shall not stand or run on floor slabs or roof slabs of water retaining structures.

24.5.8 Deposition of Fill Material

(a) Fill material shall not be deposited behind sections of walls of water retaining structures until at least seven days after completion of concreting to the section of wall.


(b) Fill material shall be spread out evenly and shall not be stockpiled on roofs to water retaining structures. Weed killer or other chemicals shall not be applied to fill material on the roofs of water retaining structures for potable or fresh water.

(c) Deposition of fill material on or adjacent to water retaining structures shall be

carried out after the watertightness test on the structure has been completed.

24.5.9 Cleaning and Sterilisation of Water Retaining Structures

(a) Immediately before water retaining structures are tested for watertightness, all dust, debris, unused materials and equipment shall be removed from the structure and the interior of the structure shall be washed and brushed down with water.

(b) Water for washing water retaining structures for potable or fresh water shall

be fresh, potable water incorporating a mixture of sterilising chemicals added before the structure is washed at a concentration reviewed without objection by the Project Manager. The structure shall be maintained in a clean condition after cleaning.

24.6 INSPECTION TESTING AND COMISSIONING 24.6.1 Testing: Drainage Systems for Water Retaining Structures

(a) Drainage systems under floors and on roofs of water retaining structures shall be tested in accordance with the following requirements:

(i) water shall be poured at different locations directed by the Project

Manager along the drainage system and the flow of water observed at junction pits, outfalls and other discharge points; and

(ii) a mandrel shall be pulled through each completed section of pipeline of

300 mm diameter or less. The mandrel shall be 750 mm long and 12 mm less in diameter than the nominal diameter of the pipe.

24.6.2 Compliance Criteria: Drainage Systems for Water Retaining Structures

(a) The results of tests on drainage systems for water retaining structures shall comply with the following requirements:

(i) water shall be freely discharged by the drainage system; and (ii) bore, linearity and jointing of pipes shall comply with the specified

requirements. 24.6.3 Non-compliance: Drainage Systems for Water Retaining Structures

If the result of any test on the drainage system for water retaining structures does not comply with the specified requirements for the test, the Contractor shall investigate the reason. Remedial or replacement work reviewed without objection by the Project Manager shall be carried out and the drainage system shall be retested.


24.6.4 Testing: Watertightness of Roofs

(a) The roofs of water retaining structures shall be tested for watertightness over the complete area of the roof, including perimeter joints. Roofs shall not be tested in sections.

(b) Water shall be ponded on the roof for a period of three days and topped up to

maintain a depth of at least 75 mm. The test shall be carried out before fill material is deposited or drainage systems are constructed on the roof.

24.6.5 Compliance Criteria: Watertightness of Roofs

There shall be no leaks or damp patches visible on the soffits of roofs of water retaining structures during or at the end of the test for watertightness.

24.6.6 Non-compliance: Watertightness of Roofs

If the result of any test for watertightness of the roof of a water retaining structure does not comply with the specified requirements for the test, the Contractor shall investigate the reason. Remedial or replacement work reviewed without objection by the Project Manager shall be carried out and the roof shall be retested.

24.6.7 Testing: Watertightness of Structures

(a) Water retaining structures shall be tested for watertightness as stated in Clause 24.6.7 (b) to (g). Each compartment of structures which incorporate division walls shall be tested separately with adjoining compartments empty and the complete structure shall also be tested.

(b) The structure shall be filled with water at an approximately uniform rate not

exceeding 2 m depth in 24 hours to the levels stated in Table 24.1. The water used for testing water retaining structures for potable or fresh water shall be fresh potable water. The Project Manager shall be notified before filling starts. The structure or each compartment of the structure being tested shall be kept full for 7 days before testing to allow for absorption.

(c) After the period for absorption, the water shall be topped up to the specified

level and the test shall begin. During testing, the oscillatory motion of the water surface shall be dampened. The test period shall be 7 days.

(d) The equipment for recording water levels shall be installed in a temporary

enclosure of minimum dimensions 2 m x 2 m x 2.5 m high with a lockable door; the enclosure shall be located over stilling wells, manhole openings or other points of recording water levels. The temporary enclosure shall be removed on completion of the test. The equipment shall be calibrated before testing starts and at regular intervals reviewed without objection by the Project Manager and shall be readable and accurate to 0.5 mm.

(e) The fall in water level in water retaining structures shall be measured at hourly

intervals between 8 a.m. and 5 p.m. each day; the total fall shall be measured at the end of the test period.


(f) Except as stated in Clause 24.6.7(g), structures shall be emptied after completion of testing and maintained in a clean and dry condition. The water shall be removed at an approximately uniform rate not exceeding 2 m depth in 24 hours. The Project Manager shall be notified before emptying starts.

(g) The water used for the final tests on water retaining structures for potable or

fresh water shall be retained in the structure and shall not be wasted or contaminated.

24.6.8 Compliance Criteria : Watertightness of Structures

(a) The results of tests for watertightness of water retaining structures shall comply with the following requirements:

(i) the total fall in water level at the end of the test period, after adjustment

for evaporation and rainfall, shall not exceed 1/500 times the maximum specified depth of water in the test or 10 mm, whichever is less; and

(ii) there shall be no leaks or damp patches visible on the surface of the

structure, including any division walls, during or at the end of the test. 24.6.9 Non-compliance: Watertightness of Structures

If the result of any test for watertightness of a water retaining structure does not comply with the specified requirements for the test, the Contractor shall investigate the reason. Remedial or replacement work reviewed without objection by the Project Manager shall be carried out and the structure shall be retested.

Table 24.1: Test on Water Retaining Structures

Type of structure Part of structure tested Test water level

Water retaining structures other than for sewage

Structure with division wall - each compartment of structure

100 mm below top of division wall

Structure with division wall - complete structure Top water level of

structure Structure without division wall

Water retaining structures for sewage

Structure with division wall - each compartment of structure

Top water level of structure Structure with division wall

- complete structure Structure without division wall

24.6.10 Samples: Water Sterilisation

After the test for watertightness of a water retaining structure for potable or fresh water has been completed, samples of the water in the structure shall be taken by the Contractor in the presence of the Project Manager. The number of samples and location of sampling shall be reviewed without objection by the Project Manager.


24.6.11 Testing: Water Sterilisation

Each sample of water shall be tested to determine the bacteriological content. 24.6.12 Compliance criteria: Water Sterilisation

The results of tests for bacteriological content of the water shall demonstrate that the structure has been adequately sterilized in compliance with the requirements of the Contract and the Relevant Authorities.

civil and structural works - hong kong … materials & workmanship specification issue no. 5,...

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