brilliance close to nature river channel and rock ramp ... · brilliance – close to nature river...

BRILLIaNCE – Close to Nature River

Channel and Rock Ramp – former Sappi

Paper Mill, Feniscowles

Civil Engineering Specification for

Section 2 - River Diversion & Channel Dressing Works

Stages 2B and 2C Contracts

22 March 2017

Revision A

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1 Quality Assurance | Client: Ribble Rivers Trust

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2 Quality Assurance | Client: Ribble Rivers Trust

QUALITY ASSURANCE

Project Name: Blackburn Mill Phase 2

Project No.: EVY_0459

Status: For TENDER

Revision B

Client: Ribble Catchment Conservation Trust Ltd

c/o Hanson Cement,

Ribblesdale Works,

Clitheroe,

Lancashire, BB7 4QF

Author 17 March 2017

John Young, BEng, MSc (Eng), CEng MICE MCIWEM Edenvale Young Associates Limited

Checked 17 March 2017

Daniel Boulden, Mng, Edenvale Young Associates

Authorised 22 March 2017

John Young, BEng, MSc (Eng), CEng MICE MCIWEM Edenvale Young Associates Limited

RECORD OF ISSUE

Document File Name Rev Date Status

170313 specification ceswi 7 stage 2b and c

rev b.docx

B 22/03/17 For Tender

170313 specification ceswi 7 stage 2b and c

rev a.docx

A 17/03/17 For Tender

3 Contents | Client: Ribble Rivers Trust

Blackburn Waterside Development:

Section 2 – River Diversion Works

CONTENTS

QUALITY ASSURANCE 2

RECORD OF ISSUE 2

CONTENTS 3

SCOPE OF SPECIFICATION 8

CONSTRUCTION PRODUCTS REGULATIONS 1991 8

DELETERIOUS MATERIALS 8

SPECIFICATION 9

INTRODUCTION 9

SECTION 1 - GENERAL 10

1.1 DEFINITIONS 10

11.6 ENTRY ONTO THE SITE 10

1.8 LEVELS AND REFERENCE POINTS 10

1.11 INTERFERENCE WITH ANY ACCESS TO PROPERTY, APPARATUS OR SERVICE 10

1.15 WORKS AFFECTING WATERCOURSES 11

1.16 WATER SUPPLY HYGIENE 13

1.25 DRAWINGS 13

1.26 SUBMISSIONS BY THE CONTRACTOR 13

MANUFACTURER'S AND CONTRACTOR'S CERTIFICATES 13

1.27 ENVIRONMENTAL BEST PRACTICE 13


SECTION 2 – MATERIALS 15

2.3 ADMIXTURES FOR CONCRETE OR GROUT 15

2.4 AGGREGATES FOR CONCRETE 15

ALKALI REACTIONS WITH CEMENT 15

COARSE AND FINE LOW-SHRINKAGE AGGREGATES 16

SAMPLES 16

2.16 CEMENT 16

2.17 CEMENT GROUTS 17

2.20 CONCRETE GENERAL 17

MIX DESIGN PARAMETERS 17

2.30 COVER BLOCKS AND SPACERS FOR REINFORCEMENT 17

2.42 FIXINGS FOR METALWORK 17

2.56 GRASS SEED AND WILD FLOWER MIXES 17

2.60 HANDRAILS AND BALUSTERS 18

2.67 JOINT SEALING COMPOUNDS AND SEALANTS 18

2.82 MORTAR 18

2.90 PIPE SURROUND MATERIALS 18

2.101 PRECAST MANHOLES AND SOAKAWAYS 19

DETAILS TO BE SUBMITTED 19

2.134 WATER 20

2.143 MARKING AND PACKING OF PIPES AND FITTINGS 20

2.144 GRILLES, SCREENS AND OTHER MISCELLANEOUS METALWORK 20

2.145ROCK 22

ROCK QUALITY 22

UNSUITABLE MATERIALS 22

MASS DISTRIBUTIONS AND GRADING 22

DENSITY 23

MECHANICAL PROPERTIES 23

WATER ABSORPTION 23

ANGULARITY 23

COLOUR AND TEXTURE 24

FREEZE-THAW 25

RESISTANCE TO WEAR 25

ARMOURSTONE INTEGRITY 25

PLACING TOLERANCES 25

2.146 DELETERIOUS MATERIALS 27


SECTION 3 - EXCAVATION, BACKFILLING AND RESTORATION 28

3.1 EXCAVATION 28

3.3 TOPSOIL 28

3.4 DEALING WITH WATER 29

3.5 TEMPORARY DRAINS 29

3.6 BACKFILLING 30

3.9 REINSTATEMENT OF UNPAVED LAND 30

3.10 TREES AND WOODY PLANTING 30

3.12 LAND DRAINS 31

3.13 FILLING ABOVE GROUND 32

FILLING FOR FLOOD DEFENCES AND FLOOD EMBANKMENTS (INFREQUENTLY WETTED) 32

GENERAL FILL 33

ROCK MATERIALS FOR USE IN RIVERS 35

ROCK MATERIALS FOR USE IN REVETMENTS AND BREAKWATERS 36

GEOTEXTILES & GEOTEXTILE-RELATED PRODUCTS USED TO SEPARATE EARTHWORKS MATERIALS 37

3.17 SITE CLEARANCE AND SURFACE STRIPPING 38

3.18 TRIAL HOLES 38

3.19 SURVEY OF FINAL GROUND LEVELS 38

3.20 MAINTENANCE OF LANDSCAPING 38


SECTION 4 - CONCRETE AND FORMWORK 39

4.1 SUPPLY OF INFORMATION 39

4.2 INITIAL TESTING 39

4.5 TRANSPORTING, PLACING AND COMPACTING 39

NOTIFICATION AND APPROVAL 39

PLACING OF CONCRETE - GENERAL 40

PLACING UNDERWATER 40

COMPACTION 41

4.6 CONCRETING IN COLD WEATHER 41

4.7 CONCRETE TEMPERATURE 41

4.8 CURING 41

4.10 CONSTRUCTION OF FORMWORK 41

4.11 CLEANING AND TREATMENT OF FORMS 42

4.14 CUTTING AND BENDING OF REINFORCEMENT 42

4.15 FIXING OF REINFORCEMENT 42

4.18 WELDING OF REINFORCEMENT 42

4.19 BUILT-IN ITEMS 42

4.20 CONSTRUCTION JOINTS 43

4.21 SURFACE FINISHES PRODUCED WITHOUT FORMWORK 43

4.22 SURFACE FINISHES PRODUCED WITH FORMWORK 43

SUPERIOR FINISH 43

GENERAL 43

4.24 TIE BOLTS FOR FORMWORK 44

4.25 TOLERANCES FOR CONCRETE SURFACES 44

4.29 SUBMISSIONS BY THE CONTRACTOR - CONCRETE AND FORMWORK 45

GENERAL 45

CERTIFICATES 45

SAMPLES 45

CONCRETE MIXES 45

FORMWORK AND REINFORCEMENT 45

RECORDS OF CONCRETING 46

OTHER SUBMISSIONS 46

4.30 SITE-MIXED CONCRETE 46

MECHANICAL MIXING 46

HAND MIXING 47

4.31 APPLIED FINISHES 47

4.32 PREPARING FOR CONCRETING 47

4.33 FIXING OF METALWORK TO CONCRETE 48

4.34 SULPHATE CONTENT OF CONCRETE 48

4.35 SAMPLING AND TESTING OF CONCRETE 48

GENERAL 48

NON-COMPLIANCE OF THE TEST RESULTS 49

4.36 MECHANICAL COUPLINGS FOR REINFORCEMENT 49

4.37 WATER STOPS 50

4.38 MOVEMENT AND EXPANSION JOINTS 50


GENERAL 50

SECTION 5 - CONSTRUCTION OF PIPELINES, TUNNELS & ANCILLARY WORKS 51

5.1 PIPE LAYING GENERALLY 51

GENERAL 51

CROSSING EXISTING PIPELINES AND BURIED CABLES 51

CROSSING WATERCOURSES 51

5.2 PIPE BEDDING 52


Scope of Specification The scope of this specification is limited to the diversion of the River Roddlesworth comprising

Section 2B and 2C of the Blackburn Waterside Regeneration development.

Construction Products Regulations 1991 The Specification sets out requirements which shall apply in addition to those of the

Construction Products Regulations 1991. These additional requirements are sometimes

specified by references to particular standards, procedures or codes of practice, but no such

reference shall be taken as precluding the use of Reference Standards or Alternative

Reference Standards as defined in the Specification.

Deleterious Materials The following products shall not be incorporated into the works:

a) Substances which have been published as being deleterious/potentially hazardous by the

Building Research Establishment or in the BPF/BCO report Good Practice in the selection of

Construction Materials (current guide) other than in accordance with the recommendation as

to good practice contained in section 2 of that report.

b) Any other substance or method of use generally known at the time of specification to be

deleterious to health and safety or to the integrity of buildings and/or other structures and/or

plant and machinery or which is not in accordance with the current British Standards Codes

of Practice or European Union equivalent for the time being in force.

9 SPECIFICATION | Client: Ribble Rivers Trust

SPECIFICATION

Introduction 1. The Specification referred to in the Tender shall consist of pages 15 to 120 of the "Civil

Engineering Specification for the Water Industry, 7th Edition", published by the Water

Authorities Association in March 2011 supplemented by the Special Clauses, and the

Appendices to the Specification herein.

2. In so far as any Special Clause or Appendix may conflict or be inconsistent with any provision

of the Civil Engineering Specification for the Water Industry, 7th Edition, the Special Clause or

Appendix shall prevail.

3. Any clauses in the Specification which relate to work or materials not required by the Works

shall be deemed not to apply.

4. The "General Notes" and the clause headings, marginal notes for guidance and "ASSOCIATED

TOPICS" (although printed on pages 11 to 166 of the "Civil Engineering Specification for the

Water Industry") do not form part of the Specification and shall not affect the interpretation

either of the Specification or of the other Contract Documents.

10 SECTION 1 - General | Client: Ribble Rivers Trust

SECTION 1 - GENERAL

1.1 Definitions 7. “Project Manager” means the person, firm or company named in the Contract as appointed

by the Client to supervise and administer the Contract or other such person, firm or company

so appointed from time to time by the Client.

8. “Employer” as referred to in the contract means the Client.

9. “Supervisor” as referred to in the contract means the Project Manager.

11.6 Entry onto the Site 6. Notwithstanding any programme submitted in accordance with the Contract, the Contractor

shall notify the Project Manager in writing 14 days in advance of his intention to enter the

Works.

1.8 Levels and Reference Points 2. The levels shown on the Drawings are related either to Ordnance Datum Newlyn (ODN) or to

a local datum, as indicated on the Drawings. Plan co-ordinates are based on the National Grid

or on a local grid, as indicated on the Drawings.

3. Any local datum which is to be demolished or excavated shall be transferred to a new and

substantial temporary bench mark in a safe position at an early stage. The level of every new

bench mark which the Contractor proposes to use for any purpose shall always be agreed with

the Project Manager before any other bench mark or datum from which it has been

transferred is removed.

4. Before the surface of any part of the Site is disturbed or the Works thereon are begun the

Contractor shall take and record levels and dimensions of that part. The Contractor shall also

take and record such other levels and dimensions as are necessary during the progress of the

work to allow accurate measurement of the different categories of work. All levels and

dimensions shall be taken and recorded in the manner agreed with the Project Manager. Such

levels and dimensions when agreed with the Project Manager shall form the basis of

measurement.

1.11 Interference with Any Access to Property, Apparatus or Service 5. Where, in the opinion of the Project Manager, construction cannot reasonably be carried out

unless apparatus is permanently severed or permanently diverted or permanently supported

he may order such permanent measures as he considers necessary to be carried out by the

Contractor or by others.

6. Notwithstanding any information regarding underground apparatus supplied by or on behalf

of the Employer or Project Manager, the Contractor shall be responsible for ascertaining from

his own inspection of the Site, and from the respective supply utilities, other relevant

companies and any public bodies, the position of all mains, pipes and cables. The Contractor

shall carry out thorough searches, including the use on the Site of electromagnetic or other

suitable locating equipment, followed by excavation by hand, to exactly locate all such

potentially dangerous apparatus.


7. In any location where power cables and other pipes carrying fluids or gases may be expected

below ground, the Contractor shall use electromagnetic or other suitable locating equipment

to find such apparatus and accurately mark their routeing on the surface prior to excavation,

sheet piling or other work below ground. When carrying out such work in areas where there

may be buried power cables, the Contractor shall re-survey at the start of each day the area

over which that day's work is to be carried out.

1.15 Works Affecting Watercourses 6. The Contractor’s attention is drawn to the fact that the river may flood. It is essential,

therefore, for the Works to be carried out in such a way as to minimise any enhancement of

flood risk,

7. The Contractor’s attention is drawn to the Land Drainage Act 1991 and the Water Resources Act 1991. Any proposals for temporary works to be carried out in or adjacent to a watercourse

or its floodplain require the formal and prior consent of the EA before construction can

commence. A consent application has to be processed within two months under the

provisions of these acts.

8. The Contractor will be required to ensure that his proposals for temporary works submitted

for approval. When submitting his proposals for temporary works to the Project Manager for

approval and before carrying out temporary works the Contractor shall confirm, in writing, to

the Project Manager that he has received the necessary approvals to his temporary works

proposals required under this clause.

9. A Temporary Works Consent will only be granted on consideration of the probable effects on

the river and other properties and will not consider their suitability for the Contractor’s purpose. These requirements are not exhaustive and shall not in any way relieve the

Contractor of his statutory obligations under the contract for temporary works affecting

watercourses, including obtaining the necessary prior consents to his proposals.

10. The Contractor shall satisfy himself as to the possibility of inundation of the Works and assess

the effects thereof on his operations and on the downstream watercourse.

11. The Contractor’s attention is drawn to the Control of Pollution provision in the Water

Resources Act 1991. He shall take all reasonable precautions to ensure that no work carried

out in any watercourse is done in such a manner as to cause pollution.

12. In particular, but not by way of derogation from the generality of this clause the Contractor:

• If the storage of oil or other polluting liquids is proposed on the Site, the contractor shall

take precautions to prevent any possible pollution of ground or surface water from this

source. Any storage tank for oil shall be protected with an oil tight bund having a capacity

of at least 10% greater than the tank within. The Control of Pollution (Silage Slurry and

Agricultural Fuel Oil) Regulations 1991 shall be compiled with.

• Shall locate any fixed plant using fuel oil as far away as reasonably possible from any

watercourse and shall surround them with oil-absorbent material to contain spills or leaks.

• Shall provide for silted or discoloured water pumped from excavations either to be

irrigated over grassland or settled in a lagoon prior to any discharge to a watercourse.

• Shall not use plant in a river or ford the river with vehicles without the Project Manager’s consent.

• Shall avoid the discharge of seepage of cement slurry from any concreting work into the

watercourse.


• Shall agree with the Project Manager his plant and vehicle parking and servicing areas.

13. If, notwithstanding these precautions, any pollution takes place, the Contractor shall forthwith

advise the Environment Agency immediately via its 24 hour control centre.

14. In executing the Works the Contractor shall not only take all necessary precautions to secure

the efficient protection of all rivers, streams and waterways, but also for the protection of

water in underground strata against silting, erosion and pollution which may be likely to

contaminate water supplies or cause injury or disturbance to animal or plant life.

15. Where, the Contract requires the removal of any part of the bottom, channel or bed of a

watercourse or deposits accumulated by reason of any dam, weir or sluice holding back

waters, the Contractor shall use his best endeavours to prevent deposits being carried away

in suspension in the waters.

16. Consent to discharge water, under the provisions for Control of Pollution in the Water

Resources Act 1991 shall be obtained by the Contractor. Further to Sub Clause 3 of this Clause

the Contractor may be subject to prosecution should pollution enter any watercourse.

17. The Contractor’s attention is drawn to the Water Resources Act 1991. The Contractor shall take all necessary precautions to secure the efficient protection of water abstractions whether

licensed or not. A list of licensed abstractions is available in a public register, but the

Contractor’s attention is also drawn to the possible existence of domestic abstractions exempt

from licensing.

18. No works shall be carried out by the Contractor which will reduce or materially alter the rate

of flow passing down a watercourse whether of a temporary nature or not.

19. Consent to abstract water, under the Water Resources Act 1991 shall be obtained by the

Contractor. Any abstraction by the Contractor shall not reduce the ability of existing

abstractors to exercise their rights.

20. The Contractor’s attention is drawn to the Salmon and Freshwater Fisheries Act 1975, the

Water Resources Act 1991 and the Wildlife and Countryside Act 1981, and he shall take all

reasonable precautions to ensure that no work in any watercourse is done in such a manner

as to cause unnecessary damage.

21. In particular, but not by way of derogation from the generality of the Clause the Contractor:-

• Shall not remove bed material for use in construction unless otherwise detailed in the

contract.

• Shall stockpile, keep clean and replace on completion of the works any bed material

required to be removed and replaced as part of the works.

• Shall only remove such vegetation as has been agreed by the Project Manager.

• Shall submit to the Project Manager his proposals for maintaining the free passage of fish

at all times.

• Shall not spray aquatic weeds at any time.

22. The Salmon and Freshwater Fisheries Act 1975 generally requires that the Contractor does not

remove bed material from the river, does not remove or spray aquatic vegetation and

maintains free passage to fish at all times. These requirements shall be observed except

where there is express provision in the Contract.


1.16 Water Supply Hygiene 5. All materials shall be selected, and all operations shall be planned and carried out, in such a

way as not to affect adversely the quality of water entering supply.

6. Storage of materials on the Site which may contaminate water supplies shall be permitted

only with the prior written approval of the Project Manager.

1.25 Drawings 1. The Project Manager may issue working drawings, reinforcement drawings, and bar schedules

in furtherance of details shown on the Drawings. The Contractor shall be responsible for

checking the correctness of bar schedules before arranging for the supply, cutting and bending

of steel reinforcement.

1.26 Submissions by the Contractor 1. The Contractor shall submit for approval in duplicate full particulars, including drawings and

calculations, of any of the Temporary Works. If required, the Contractor shall also submit

calculations of the stresses strains and deflections which will arise in falsework or other

Temporary Works and these shall be accompanied by detailed working drawings. Approval

by the Project Manager of the Contractor's drawings and calculations shall not relieve the

Contractor of any of his duties or responsibilities under the Contract.

2. All such particulars submitted for approval shall be certified and signed by the Contractor to

be correct. They shall use the SI units. Each submission of particulars shall follow a logical

reference numbering system. Any revision of the particulars by the Contractor shall be clearly

identified and resubmitted for approval.

3. Drawings shall be clearly printed in black on white and shall be resistant to fading. Sheet sizes

shall be in accordance with A series to ISO 216 and not larger than A1 size.

Manufacturer's and Contractor's Certificates 5. Where certificates are required by the Specification or a publication quoted in the

Specification, the original and two copies of each such certificate shall be provided by the

Contractor. Certificates shall be clearly identified by serial or reference number where

possible to the material being certified and shall include the information required by the

Specification and the relevant publication quoted in the Specification.

6. The timing for submission of certificates shall be as follows:-

• Manufacturer's and supplier's test certificates shall be submitted as soon as the tests have

been completed and in any case not less than 7 days prior to the time that the materials

represented by such certificates are needed for incorporation into the Permanent Works.

• Certificates of tests carried out during the construction or on completion of parts of the

Permanent Works shall be submitted within 7 days of the completion of the test.

1.27 Environmental Best Practice 1. The Client is committed to the environmental principles of stewardship and sustainability and

has corporate goals to maintain and enhance the water environment. The Contractor shall

plan and order all his activities to assist the Employer to achieve these goals.

2. In addition to this general requirement, particular areas for action are: -

• Avoidance of pollution of any waters, (surface or underground)


• Avoidance of pollution of any land

• Preservation of flora and fauna

• Avoidance of nuisance of sounds, vibrations and dust

3. The Contractor shall demonstrate in his written Method Statement his proposals to minimise

environmental impact and satisfy the above requirements. The following should be addressed

in the Method Statement: -

• Plant which leaks any fuel, lubricant or hydraulic fluid shall not be used.

• Bio-degradable hydraulic fluid is preferred.

• Plant shall be maintained to ensure efficiency and to minimise emissions.

• Plant shall be steam cleaned prior to delivery to the site.

• Fuel and oil storage shall be away from watercourses, fully bunded to 110% of the volume

stored and maintained in a secure and clean manner. Delivery and vent pipes shall

terminate within the bund.

• Refuelling or servicing of plant shall be carried out in designated locations away from

watercourses.

• Refuelling shall be supervised and shall be carried out by pumping through a trigger type

delivery nozzle.

• An adequate supply of oil absorbent materials shall be readily available on site at all times

(e.g., in cab of plant).

• Any spillage shall be immediately contained, removed from site and disposed to a licensed

tip, the Project Manager being promptly informed.

• Concrete shuttering shall be designed to avoid escape of cementitious material, especially

where it would contaminate water.

• Timber used for temporary works shall be from a temperate sustainable resource.

• Protection of trees and other vegetation, as specification clause 3.10.

• Plant shall be effectively silenced and shall comply with any stated requirements of the

Local Authority.

• Timber preservative treatment shall be carried out away from watercourses and in a

manner to avoid any spillage or loss.

4. Where materials arising from or required for the "Works" constitute Controlled Waste under

the Environmental Protection Act 1990 (Sections 33 and 34), the Contractor shall provide the

Project Manager with a copy of the Carriers' licence to transport the materials and copies of

all Waste transfer notes.

5. All new timber shall be provided from a managed renewable resource and certified as such by

an independent inspection agency accredited by the Forest Stewardship Council.

6. Peat shall not be imported to the site for use as a soil conditioner for landscaping and planting.

Peat naturally occurring on the site may only be used if it is already present at the location of

planting. It must not be moved around the site.

7. Imported soil conditioners shall be free from Peat and Coir, be manufactured from composted

matter, recycled and renewable materials fully pasteurised and free from weed seeds, disease

and fungal organisms. The Contractor shall provide details of any proposed soil conditioner

for approval prior to commencement of landscaping works.

15 SECTION 2 – Materials | Client: Ribble Rivers Trust

SECTION 2 – MATERIALS

2.3 Admixtures for Concrete or Grout 3. No admixture shall be incorporated unless specifically approved by the Project Manager.

2.4 Aggregates for Concrete 5. Aggregates for concrete shall be obtained from an approved source, shall conform to the

requirements of BS 882 and shall be washed clean. Aggregates shall not be obtained from the

wastes of metalliferous mining.

6. Marine coarse aggregates shall conform to the requirements of BS 882 in regard to shell

content, measured in accordance with BS 812: Part 106. Marine fine aggregates, defined as

passing a 5mm sieve, shall contain no more shell than 30% by mass of dry aggregate. Shell

shall be measured as calcium carbonate.

7. Oolitic limestone gravels may be used provided that satisfactory results are submitted from

tests for aggregate impact value or 10% fines value carried out within the six months preceding

its proposed use. Evidence shall also be provided that the aggregates have been consistent in

these properties over a period of at least two years. No other form of oolitic limestone shall

be used.

Alkali reactions with cement 8. The fine and coarse aggregates shall each consist of at least 95% of one or more of the rock

types tabulated below. Sources of aggregates shall not contain opaline silica or quantities of

flint, chert or chalcedony that could cause damage from alkali-silica reaction.

Air cooled blast

Furnace slag

Andesite

Basalt

Diorite

Dolerite

Dolomite

Expanded clay/shale/slate

Feldspar

Gabbro

Gneiss

Granite

Limestone

Marble

Microgranite

Quartz

Schist

Sintered pfa

Slate

Syenite

Trachyte

Tuff

9 If the above requirements cannot be met the Contractor shall adopt constituents for his

concrete such that either:

• The cementitious material shall have a reactive alkali content not exceeding a maximum

value of 0.6% by mass when defined and tested in accordance with the method described

in Clauses 16 and 17 of Concrete Society Technical Report No.TR30; or

• the total mass of reactive alkali in the concrete mix shall not exceed 2.5 kg per m3 of

concrete when defined, tested and calculated in accordance with the method described

in Clause 16 and 18 of Concrete Society Technical Report No.TR30.


9. The water-soluble chloride content of aggregates shall be determined in accordance with

BS 812: Part 117 and the sulphate content in accordance with BS 812: Part 118. The limits on

the contents shall be such that the concrete mix as a whole complies with the provisions of

Clauses 4.9.2 and 4.39.1 respectively.

Coarse and fine low-shrinkage aggregates 10. The coarse aggregates shall be capable of producing concrete having a drying shrinkage of not

more than 0.065% when tested in accordance with BS 812: Part 120.

11. The Contractor shall produce test sheets from the supplier certifying compliance with the

stipulated requirement. Where such test sheets are not available, tests shall be carried out

by the Contractor to establish the suitability of the proposed source of supply.

12. Where a source of supply produces coarse aggregates which do not satisfy the stipulated

shrinkage requirement, such a source shall not be used for the supply of fine aggregates.

Samples 13. Before work on trial mixes of concrete is commenced, the Contractor shall submit for approval

samples 50 kg in weight of each aggregate which he proposes to use. The source of each

aggregate shall be clearly marked on the container of each sample. Samples approved by the

Project Manager shall remain preserved at Site for reference.

14. The Contractor shall sample and carry out a mechanical analysis of the fine aggregate and each

nominal size of coarse aggregate in use employing the methods described in BS 882 at least

once each week when concreting is in progress and at such more frequent intervals as the

Project Manager may require. Should the fraction of aggregate retained on any sieve differ

from the corresponding fraction of aggregate in the approved mix by more than two percent

of the total quantity of fine and coarse aggregate the Contractor shall alter the relative

proportions of the aggregates in the mix to allow for such difference.

2.16 Cement 4. Cement shall generally be BS12, but containing not less than 5% and not more than 9% by

weight of tricalcium aluminate (C3A) (with optional requirement for high sulphate resistance).

In either case the cement shall not contain more than 2.7% by weight of sulphur trioxide.

Cement shall conform to the following codes of practice:-

• Ordinary Portland Cement to EN 197-1 / BS12

• Portland Blast Furnace Cement to EN 197-1 / BS146

• High Slag Blast Furnace Cement to EN 197-1 / BS4246

• Ground Granulated Blast Furnace Slag to EN 197-1 / BS 6699

5. Combinations of Portland Cement and ground granulated blast furnace slag (ggbs) made in

the blended in the mixer will not be permitted. Cements shall be obtained from an approved

manufacturer and shall be delivered to the site or premix works in bulk cement lorries of

approved design or in sealed bags clearly marked with the marker's name. The Contractor

shall further ensure test certificates show that the total alkali content of the cement expressed

as the sodium oxide (Na2O) equivalent does not exceed 0.6% as determined by BS 4550, Part

2.


6. The Employer will require the Contractor to submit the Manufacturer's Certificate indicating

compliance with the relevant Standards contained in this specification. The Employer will

require the Contractor at any time to submit samples of cement for testing. Such samples

shall weigh not less than 7kg and shall be selected and tested in accordance with BS4550.

7. Cement shall be stored and maintained under dry conditions, with each parcel or consignment

separately stored to facilitate inspection, testing and approval where required. Different

grades of cement shall be separately stacked. Any cement that has been adversely affected

shall be removed from the site immediately.

2.17 Cement Grouts 4. Grout mix G7 shall be a neat cement grout with the addition of a non-shrink additive such as

"Conbex" manufactured by Fosroc CCD Ltd and used in accordance with the manufacturer's

instructions

2.20 Concrete General 6. Notwithstanding clauses 2.20.1 to 2.20.6 in-situ and pre-cast concrete shall comply with BS

6349 Part 1.

Mix design parameters 7. The Contractor shall submit for approval concrete mix designs for each grade of concrete to

be used in the works. The design parameters for these mixes are set out in Table 1 (marine

environment). The Concrete strength is defined in terms of the 28 day characteristic cube

strength. The strengths and other parameters specified are those assumed for the design of

the structure and must be achieved by the Contractor in the finished Works.

8 The mix designs shall take account of the requirements for concrete to resist chemical attack

from the soil or ground in which it is to be placed, with due regard to geotechnical test results.

2.30 Cover Blocks and Spacers for Reinforcement 4. Concrete cover blocks shall have the same colour and texture as the surrounding concrete.

2.42 Fixings for Metalwork 4. Washers used with rag and indented bolts or in other bolted connections shall be hot dipped

galvanised in accordance with BS 729 where used with galvanised fixings and shall be stainless

steel where used with stainless steel fixings.

5. Fixing bolts for metalwork may be of a proprietary type designed for fixing into drilled holes

using pre-packed epoxy resin materials providing this cannot cause additional hazard in case

of fire and providing the fixings are not subject to long term tensile loading.

6. The grades of hardness of stainless steel used in bolts and associated fixings shall be such as

to avoid seizing problems and an anti-seize lubricant shall be used with such bolts.

2.56 Grass Seed and Wild Flower Mixes 2. The germination capacities, the purity of the mixture and the weed and other crop seeds

content of the grass seed mixture shall comply with the recommendations of BS 4428. A

certificate from the seed merchant that the mixture corresponds with the specified mixture

shall be provided.

3. Seed shall be delivered to the Site in bags provided by the seed merchant and stored in a

weather tight and properly ventilated structure.


2.60 Handrails and Balusters 6. The design loading shall be in accordance with BS 6180 Table 2 (c) to (f).

7. Balusters for external hand-railing shall be solid.

8. Handrails shall be flush jointed.

9. Whilst in general the dimensions and pattern of all hand-railing shall be as indicated on the

Drawings the Contractor shall submit fabrication drawings for the approval of the Project

Manager prior to manufacture.

2.67 Joint Sealing Compounds and Sealants 7. The manufacturer's recommendations for storage, shelf life, preparation, priming, mixing and

installation of proprietary sealing compounds shall be strictly adhered to.

2.82 Mortar 5. Mortar for bedding and jointing masonry shall normally be Class M3. Plasticisers or

proprietary "masonry cements" may be used where approved by the Project Manager, in

which case the proportions of the mix shall be based upon the manufacturer's instructions.

6. Cement/lime/sand mortar shall be made by mixing cement with sand while dry and adding

lime putty and water subsequently.

7. The mortar shall be mixed dry in a machine or on a clean, watertight platform until a uniform

colour and shall then be wetted whilst undergoing further mixing. Mortar shall be prepared

in such quantities that it is incorporated in the completed work within 30 minutes of first

wetting the mix. No softening or re-tempering shall be allowed.

2.90 Pipe Surround Materials 3. Type "A" granular material shall be aggregates from natural sources complying with the

provisions of BS 882 and with the recommendations of WIs No.4-08-01 and requirements of

WIs No 4-08-02. The aggregates shall be clean, hard, free-draining and chemically stable

gravels or crushed rock. Unless otherwise specified, grading shall comply with Clause 5.1 of

BS 882; the `dry sieving' alternative described in Clause 3.2 of BS 812: Part 103 shall not be

used.

4 Reference to these aggregates shall distinguish between graded and single-sized materials as

follows:-

• E.g. Type A (20-5) shall mean a graded aggregate with 20 mm nominal maximum size.

• E.g. Type A (10) shall mean a single sized aggregate with 10 mm nominal maximum size.

When determined in accordance with BS 812: Part 111, using specimens in the soaked

condition, the 10% fines value shall be not less than 100 kN.

4. Type "AF" granular material for bedding and haunching flexible pipes such as thin walled steel,

GRP and large dia. ductile iron, shall be well graded Type "A" granular material with 100%

passing a 10 mm sieve and no particles passing a 0.1 mm sieve.

5. Sand for bedding pipes shall comply with the provisions of BS 882, Table 5 for Grading Zone C.


6. Selected main backfill Type B, whether selected from locally excavated material or imported,

shall consist of uniform readily compactable material, free from vegetable matter, building

rubbish and frozen material, or materials susceptible to spontaneous combustion, and

excluding clay of liquid limit greater than 50 and materials of excessively high moisture

content. Clay lumps and stones retained on 75 mm and 37.5 mm sieves respectively shall be

excluded from the fill material.

7. Type "BX" selected fill material shall be similar to Type "B" in all respects except that clay

lumps and stones retained on 37.5mm and 20mm sieves respectively shall be excluded.

2.101 Precast Manholes and Soakaways 4. Concrete for precast concrete box culverts shall:

• comply with the requirement of BS 8500-2;

• have a minimum compressive strength class C32/40;

• the maximum w/c ratio and minimum cement content shall comply with the requirements

of Table A5 BS 8500-1 for Exposure Class XD1.

• permitted cements include al in Table A6 BS 8500-1

• for maximum aggregate size other than 20 mm maximum w/c ratio and minimum cement

content shall comply with the requirements of Table A7 BS 8500-1;

• the chloride class where a class other than Cl 0,40 is required;

• the class of consistence shall be S3

• concrete cover to reinforcement shall comply with the requirements of Table A5 BS8500-

1 for Exposure Class XD1.

5. All units shall be laid, bedded, jointed and fixed in accordance with the lines, levels and other

details shown on the Drawings.

6. At all stages and until completion of the Works, precast members, where they are liable to

damage due to their location, shall be adequately protected to preserve all permanently

exposed surfaces, arises and architectural features. The protection shall not mark or

otherwise disfigure the concrete.

7. Dry-pack mortar jointing for packing shall consist of one part by volume ordinary Portland

cement and two parts by volume of fine aggregate passing a 1 mm sieve. The mortar shall be

mixed with only sufficient water to make the materials stick together when being moulded in

the hands. The mortar shall be placed and packed in stages where possible from both sides

of the space being filled, until the mortar is thoroughly compacted.

8. Any precast concrete item which is found to be cracked, damaged or otherwise inferior in

quality before or after installation shall be rejected and replaced by the Contractor.

Details to be submitted 10. Before manufacture of structural precast concrete members is commenced the Contractor

shall submit for approval full details of his proposed method of carrying out all operations

connected with the manufacture and assembly of precast concrete structural members,

including: -

• Description of the types of casting bed, mould and formwork for the various types of

members.

• Procedure for concrete casting and the method for curing the concrete.


• Procedure for transporting, handling, hoisting and placing of each type of precast

structural member.

• Particulars of temporary supports necessary to ensure adequate stability during erection

and against the effects of construction loads, wind load or other transient loads.

• Structural calculations.

2.134 Water 2. Alternatively, non-potable water may be used for aggregate washing, mixing and curing

concrete, mortar and grout provided that it is clean and free from harmful matter and satisfies

the recommendations in the Appendix to BS 3148.

3. The concentrations of chlorides and sulphates in water for mixing concrete shall be such that

the concrete mix as a whole complies with the limits of salts content specified in Clauses 4.9.2

and 4.39.1.

2.143 Marking and Packing of Pipes and Fittings 1. Each pipe and fitting shall be indelibly marked with the diameter, class and works test

pressure. Wherever possible the identification marks shall be painted on the outside of pipes

and fittings close to one end, which in the case of pipes and fittings with socket and spigot

joints shall be the socket end.

2. Where there is insufficient smooth surface area to accommodate the above information the

marking shall be put on rust proofed metal tags secured to the item with galvanised wire.

3. All other pipe ends shall be protected against impact damage and entry of foreign matter.

2.144 Grilles, Screens and Other Miscellaneous Metalwork 1. All mild steel fabrications and associated cleats, brackets, packing pieces and the like shall be

made off Site in workshops approved by the Project Manager and shall be galvanised before

delivery to Site.

2. Surface preparation and hot dip galvanising shall be in accordance with BS 729. The total

nominal thickness of the coating shall be 140 microns: System Reference SB 2 in BS 5493

(equivalent to 995 g/m²).

3. The Contractor shall supply and install the items of metalwork shown on the Drawings

together with all fixings, mounting brackets, locking screws, lifting keys and other accessories

normally required for erection, permanent fixing and operation.

4 No orders for engineering metalwork shall be placed by the Contractor until he has submitted

his detailed drawings, and where applicable supporting design calculations, to the Project

Manager and received the Project Manager’s consent.

5 Where the Contractor proposes to use dissimilar metals either in contact or close enough for

the gap between them to be bridged by an electrolyte, he shall satisfy the Project Manager

that adequate anti-corrosion provision is included in the design.

6 Steel items for which there is no relevant standard shall be fabricated as shown on the

Drawings from steel which is in accordance with BS 4360, Grade 43A, by welding using

procedures in accordance with BS 5l35.

7 Items of aluminium and aluminium alloy shall comply with the relevant provisions of BS 1470,

BS 1471 and BS 1474.


8 Unless otherwise specified or shown on the Drawings, steel ladders shall be generally in

accordance with BS 4211 for Class A ladders with solid steel stringers (stiles) but shall have the

following dimensions:

• minimum thickness of stringer l2 mm

• diameter of rungs 20 mm

• rung spacing 250 mm

• rung length between stringers 400 mm

• minimum clearance to wall or other obstruction 220 mm

• maximum distance between stringer supports 2.0 m

9 Stringers shall extend 1.0 m above the level of the floor or platform at the top of the ladder

and the clear width between stringers shall be increased to 600 mm for this length.

10 The stringers shall be sized to suit the height of ladder and the intervals of the stringer

supports. Stringers shall be drilled to receive the rungs which shall be welded to the stringers

on each side of each stringer. Unless otherwise detailed on the Drawings, the bottom ends

of the stringers shall not be designed for floor fixing, but shall terminate at wall fixing supports

at least l50 mm above the floor. All edges of stringers, brackets, slice plates and other

components shall be ground smooth to remove burrs and sharp edges.

11 Ladders exceeding 3m high shall be provided with safety hoops at intervals not exceeding 900

mm, with the lowest hoop 2.5 m above the ladder foot unless otherwise specified or shown

on the Drawings. Unless provided otherwise, landings of open mesh flooring and handrails as

specified shall be provided at intervals not greater than 9 m. When detailed on the Drawings,

anchorage points shall be provided for attaching safety harnesses instead of the above safety

hoops.

12 Metal handrailing shall comply with the relevant recommendations of BS 6180. Except where

otherwise specified or shown on the Drawings, metal handrailing shall consist of standards at

regular intervals not exceeding l.5 m, and two rails. The upper rail shall be l.1 m above the

adjacent finished floor level, and 0.9 m above the nosing line on stairways. The lower rail shall

be midway between floor or nosing line and the upper rail. Rails shall be fabricated from 32

mm bore mild steel tube and standards from 38 mm dia solid mild steel bar.

13 Handrailing shall be ball-jointed. Handrailing terminating against a wall shall either have a

suitable wall fixing flange or shall terminate at a standard or a loop with a gap between the

standard or loop and the wall not exceeding 75 mm. Where the shape of the floor or platform

structure does not incorporate an upstand at the edge of walkways, toe plates not less than 5

mm thick and not less than l00 mm high shall be fixed to the handrail standards. The bottom

edge of such toe plates shall be not more than 25 mm above the surface of the walkway.

14 The handrail standards for stairways and for landings and walkways of width less than l.2 m

shall have palm fittings for bolting to the sides of the structures. Elsewhere the standards shall

be designed for fixing l00 mm (minimum) inside the edge of concrete structures, or at the

supporting edge girder of steel flooring, or have palm fittings as detailed on the Drawings.

Standards either side of openings shall be equipped with eyes for attaching safety chains at

top and middle rail level.

15 Safety chains shall be of mild steel of l0 mm nominal size, short link, smooth welded chain in

accordance with BS 4942, Part 2. Each length of chain shall be fitted with a shackle at one end

and a snap fastening at the other.


16 Where metalwork is to be founded on and/or fastened to concrete the Contractor shall use

one of the following methods:-

• Bolting or screwing the metalwork to plates or angle section having anchors cast into the

concrete structure or set into pockets left in the concrete structure.

• Setting the metalwork into pockets left in the concrete structure.

• Bolting the metalwork to anchor bolts (studs) cast into the concrete structure or set into

pockets left in the concrete structure.

• Bolting the metalwork to anchor bolts (studs) as specified, in holes drilled into concrete

structure.

• Bedding the metalwork on cement mortar placed on the concrete surface.

2.145Rock

Rock Quality 1 All rock shall be quarry stone, from an approved quarry. It shall be of suitable quality to ensure

permanence in the structure and to withstand: high current velocities, wave action, abrasion

and the climatic conditions. The stone shall be dense, hard, sound, durable rock, free of

cracks, seams and overburden material, close-grained, and highly resistant to weathering and

disintegration under hot weather and wetting-drying cycles.

Unsuitable materials 2 Unsuitable material shall include, but not be limited to the following:

• Perishable and organic materials

• Materials containing scrap and rubbish

3 All unsuitable material shall be removed from site. When, on the basis, of visual judgement of

the rock batch delivered to the site, non-homogeneity or possible non-homogeneity of the

batch is considered to exist with regard to one or more of the relevant qualities, that batch

has to be divided into parts supposed to be homogeneous. Sampling for those qualities must

be carried out on the supposedly homogeneous divided parts.

4 When one of the divided parts does not satisfy the requirements, according to the results of

the inspection, then the whole batch of quarried stone is taken to be unsuitable. If separation

of the divided part(s), which does (do) not satisfy the requirements, is possible without

difficulty, it can be agreed to regard the remaining part of the batch as a separate batch.

Mass Distributions and Grading 5 The maximum size for rock used in gabions or mattresses shall not exceed two thirds of the

minimum dimension of the gabion/mattress compartment or 200mm whichever is smaller

and the minimum size of the fill shall not be less than the size of the mesh opening.

6 Primary, secondary rock armour, scour protection and rip rap shall have the minimum and

maximum dimensions / masses as stated in Table 1 and Table 2. For primary and secondary

rock armour with a nominal mass greater than 250kg (see Table 1) at least 50% in number of

the individual pieces shall have a mass exceeding the mean of the specified maximum and

minimum masses.


7 For rock with a nominal size greater than 30kg but less than 200kg the mass distribution shall

be converted to particle size and shall fall within the size grading requirements shown in in

Table 2. The mass distribution for shall be tested and reported in accordance with BS EN

13383-2:2002 Section 6.

8 Where the maximum particle size is less than 360 mm (equivalent to 125 kg), rock materials

shall be shall be tested and reported in accordance with BS EN 13383-2:2002 Section 5.

Channel bed, rock filter, underlayers, core martial and scour / erosion protection, shall comply

with the grading shown in Table 2 and Table 3. In addition, to the above requirements material

used for rock filters and underlayers 0% to 5% of materials shall pass a sieve size of 22.4mm.

Density 9 The minimum apparent relative density for following material shall be 2.5:

• channel bed, slabstones, blockstone, boulders, scour and erosion protection for use in

river works and;

• primary, secondary armour, rip rap rock, filter, underlayers, core martial and scour /

erosion protection;

The minimum apparent relative density for all other stone shall be 2.4. Rock materials shall be

shall be tested and reported in accordance with BS EN 13383-2:2002 Section 8.

Mechanical Properties 10 Channel bed, Slabstones, Primary Armour, Secondary Armour and Rip Rap materials shall be

tested to determine their resistance to breakage. Compressive strength will be determined in

accordance with BS EN 1926 1999 and Point Load Strength in accordance with the

International Society for Rock Mechanics 1985 method (http://www.isrm.net/gca/?id=177).

Compressive and point load strengths shall not be less than:-

• Compressive Strength 75 MPa

• Point Load Strength 3 MPa

Water Absorption 11 Water absorption shall not be more than:

• 3% (m/m) for primary armour, secondary armour, scour protection and rip rap in

revetments and breakwaters;

• 5% (m/m) for scour protection, cores and underlayers in revetments and breakwaters;

• 5% (m/m) for scour protection, cores and underlayers channel bed, slabstones,

blockstone, boulders, scour and erosion protection for use in river works

Rock materials shall be shall be tested and reported in accordance with BS EN 13383-2:2002

Section 8.

Angularity 12 Rock for use in rivers shall be angular or rounded. Rock showing signs of significant edge or

corner wear shall not be accepted. The rock shall not contain more than 5% of rock with a

length to thickness ratio of greater than 5. The length to thickness ratio shall be determined

in accordance with EN 13383-2:2002, clause 7.


Primary and Secondary

Rock Armour

Classification

Minimum Mass

of Individual

piece of rock

(kg)

Nominal Mass

(kg)

Maximum Mass

of Individual

piece of rock

(kg)

Type A 100 200 300

Type B 150 250 350

Type C 250 300 350

Type D 300 400 500

Type E 350 500 650

Type F 500 750 1000

Type G 750 1000 1250

Type H 1000 1500 2000

Type I 2000 2500 3000

Type J 3000 4000 5000

Type K 4000 5000 6000

Type L 6000 7000 8000 Table 1| Mass Grading

Rip Rap, Scour

Protection & Filter

Classification

Dn15

(mm)

Dn50

(mm)

Dn85

(mm)

Type 1 75 125 175

Type 2 100 150 200

Type 3 125 175 225

Type 4 150 200 250

Type 5 200 250 300

Type 6 250 300 350 Table 2| Particle Size Grading

BS Sieve Size

(mm)

% min

passing

% max

passing

90 85 100

63 40 85

22.4 15 50

6.3 0 15 Table 3| Rock Core Materials

13 Rock for use in revetments and breakwaters shall be angular and rock showing signs of

significant edge or corner wear shall not be accepted. The rock shall not contain more than

5% of rock with a length to thickness ratio of greater than 3. The length to thickness ratio shall

be determined in accordance with EN 13383-2:2002, clause 7.

Colour and Texture 14 All rock used for facing of structures shall be of a consistent colour and texture. If in the

opinion of the Project Manager the colour or texture of rock used for facing is inconsistent for

whatever reason, then the Contractor shall remove the rock and replace it with rock of a

suitable match.


Freeze-Thaw 15 Rock materials for use for Primary Armour, Secondary Armour and Rip Rap shall be shall be

tested for freeze thaw action and reported in accordance with BS EN 13383-2:2002 Section 9.

Resistance to Wear 16 The resistance to wear of Primary Armour, Secondary Armour and Rip Rap materials will be

assessed in accordance with EN 1097-1:1996, clause 7 and BS EN 13383-1:2002. The micro-

Deval Coefficient shall not be greater than 30 commensurate with a moderately abrasive

environment (Table 10: BS EN 13383-1:2002)

Armourstone Integrity 17 Primary Armour, Secondary Armour and Rip Rap materials falling within the categories shown

in Table 1 shall be tested to determine armourstone integrity. This shall be undertaken

through a Drop Test as follows:-

• A minimum of 50 samples shall be tested. The weight of each sample shall be weighed

and recorded before the drop test.

• The grading of the samples shall be tested in accordance with BS EN 13383:1 2002 to

ensure compliance with the required grading shown on the Contract Drawings

• The rock shall be dropped onto a platform (anvil) comprising rock material similar to the

sample.

• The drop height will be 3m plus or minus 0.1m.

• Following individual Drop Tests photograph, collect and weigh materials whose mass is

greater or close to the ELL mass. Record the mass of the heaviest of these pieces.

• Clear the platform / anvil of all material before performing the next Drop Test.

18 On completion of Drop Testing for the full sample calculate the drop test breakage index (Id50)

by:-

• Plotting the cumulative mass distribution curves for the total (50 block sample) before

drop testing and by linear interpolation of the cumulative plot calculate the median

sample mas before testing Mi50.

• Plotting the cumulative mass distribution curves after testing after drop testing for all

pieces heavier than the ELL and by linear interpolation of the cumulative plot calculate the

median sample mas after testing MfELL50.

• Calculate the drop test breakage index using the following formulae.

Id50 = (Mi50 – MfELL50)/Mi50

19 The test report shall include:-

• Identity of the laboratory and / or quarry

• Identification of the sample

• The nominal grading from which the sample was taken

• Visual observations and photographs of the sample before and after the drop test

• Mass of the samples before and after testing

• Mass distribution curves and drop test breakage indices (Id50)

Placing Tolerances 20 The tolerances for placed rock normal to the surface shall be:

Tolerances


River Channels (Channel Bed) Plus 0mm Minus 300mm

River Channels (Channel Sides) Plus 0mm Minus 300mm

Upper surface of the core (placed in the dry) Plus 150mm Minus 150mm

Upper surface of the core (placed underwater) Plus 300mm Minus 300mm

Upper surface filter/underlayers Plus 150mm Minus 0 mm

Upper surface of rip-rap Plus 300mm Minus 0 mm

Upper surface of rock armour Plus 500mm Minus 0 mm

Upper surface of rock armour (with mortar joints) Plus 150mm Minus 0 mm

Table 4| Setting Out Tolerances

21 Rock material placed but not meeting these criteria shall be reworked by the Contractor as

directed by the Owner at no additional cost to the Owner. Armour placing shall be balanced

so that side slopes are no steeper, and the thickness of the armour layer shall not be less, than

shown on the drawings.


2.146 Deleterious Materials 1 Notwithstanding any requirement contained in this specification the following products shall not

be incorporated into the works:

• Substances which have been published as being deleterious/potentially hazardous by the

Building Research Establishment or in the BPF/BCO report Good Practice in the selection

of Construction Materials (current guide) other than in accordance with the

recommendation as to good practice contained in section 2 of that report.

• Any other substance or method of use generally known at the time of specification to be

deleterious to health and safety or to the integrity of buildings and/or other structures

and/or plant and machinery or which is not in accordance with the current British

Standards Codes of Practice or European Union equivalent for the time being in force.

28 SECTION 3 - Excavation, Backfilling and Restoration | Client: Ribble Rivers Trust

SECTION 3 - EXCAVATION, BACKFILLING AND RESTORATION

3.1 Excavation 9. Further to Clause 3.1.2 when the Final Surface of any excavation is considered by the Project

Manager to be unsuitable or to have been damaged or allowed to deteriorate he may direct

the Contractor to excavate further and then to refill to the specified Final Surface with

concrete, selected excavated material or selected imported material, or to take such other

measures as he considers necessary.

10. Cutting slopes or toes of cuttings shall only be undercut when required in the contract for

trench or other excavations. Such excavations shall be restricted in extent and where they

require backfilling shall remain open only for the minimum period necessary, so as to prevent

risk to the permanent work.

11. The excavation of cuttings may be halted at any stage providing at least 300 mm of material

as a weather protection is left in place above the formation or above the sub-formation.

12. Final faces of cuttings which are not to receive topsoil shall:

• wherever possible be left without scars or damage from construction plant; and

• have boulders or other rock fragments that can be moved by hand without tools,

removed; and

• have adequate access to enable inspection to be carried out to determine the extent of

work required by this sub-Clause.

13. Cuttings which are not required to receive topsoil shall have one or more of the following

measures carried out as appropriate:

a) Isolated patches of soft, fragmented and insecure material shall each be excavated to

a depth of at least 200 mm and replaced as soon as practicable with General Fill and

compacted into the cleaned out void.

b) Soft or insecure material, interlayered with rock shall be excavated behind the

resulting cavity shall be filled to at least 200 mm and replaced as soon as practicable

with General Fill and compacted into the cleaned out void

c) Netting or other sheet covering.

3.3 Topsoil The title of Clause 3.3 “Topsoil for re-use” is replaced with “Topsoil”.

5. Imported topsoil shall comply with BS3882 Classification for Multi-Purpose topsoil. A

certificate shall be supplied for each delivery to ensure consistency and quality of topsoil.

6. Temporary stockpiles of topsoil shall not exceed 1.5 m in height and the topsoil therein shall

not be brought into contact with, or compressed by, any machinery.

7. Topsoil stripping shall be carried out under dry conditions. The Project Manager shall have

the power to stop topsoil stripping or movement of material if, in his opinion, the conditions

are causing damage to the topsoil or subsoil.


8. Movement of equipment on site must be controlled to prevent compaction of the topsoil and

smearing. Under no circumstance shall scraper blades be used to level topsoil. Compaction

plant shall not be used on topsoil.

9. Topsoil shall not be stripped from areas on which topsoil or turf are to be stored.

10. Topsoil stripping and replacement shall be carried out with the minimum amount of

“mauling”, (moving soil around destroying the structure). Topsoil stripping or replacement

shall cease if the Project Manager judges weather/ground conditions to be unsuitable.

11. Subsoils should be stored in separate heaps from topsoil and underlying material, and where

different qualities of subsoil exist, these shall also be stored separately so they can be restored

at the correct depth within the reinstated profile.

12. To minimise the risk of soil structural damage, movement of topsoil and subsoil should be

avoided under wet conditions.

13. In the excavation areas, the layers of underlying material and subsoil should be carefully

replaced in sequence. Following either the subsoil or topsoil replacement stage any stones

brought to the surface with a dimension greater than 100 mm should be removed.

14. Topsoils shall be replaced with mechanical excavators in such a way to avoid recompaction by

minimising machinery movement over the loose subsoil. The mechanical excavator replacing

the topsoil shall move along the working strip once only, lifting the topsoil from the linear

heap and depositing it evenly across the reinstated subsoil. Nothing other than a light

combing action by the excavator bucket should be done to level uneven topsoil.

15. The Contractor shall seed the topsoil using normal agricultural practices in dry conditions using

a locally available grass seed mix to the approval of the Project Manager.

3.4 Dealing with Water 5. The Contractor shall keep the Works clear of water at all times (including during floods) when

construction work (including installation work under other contracts listed in the Description

of Works) is in progress. Temporary Works provided by the Contractor including pumps and

well point dewatering plant shall not be removed without the approval of the Project

Manager.

6. Earthworks operations shall be carried out in a manner which will not block or impede the

natural flow of water in streams or through existing drains, pipes and culverts. No material

shall be stockpiled or existing ground disturbed, such that it may slide or fall into a stream

course or in front of a drain, pipe or culvert inlet.

7. Any temporary diversions of watercourses shall be agreed with the Project Manager in

advance of work commencing.

3.5 Temporary Drains 4. Temporary drains of the type described in Clauses 3.5.1 to 3.5.3, or any other drain which the

Contractor may wish to install below the Final Surface of any excavation, may be incorporated

only with the prior approval of the Project Manager.


3.6 Backfilling 6. Any tests which require visual examination of pipe joints, wall surfaces and the like shall be

completed to the satisfaction of the Project Manager before backfilling commences.

7. The surfaces of all excavations shall be dry and free from unsuitable material before backfilling

is commenced.

8. Should backfilling material, while acceptable at the time of selection, become unacceptable

to the Project Manager for any reason the Contractor shall remove such material and replace

it with fresh approved material.

9. Compaction of general backfilling shall be adequate to maintain the required stable ground

surface levels.

10. Where filling is beneath structures, compaction shall be adequate to achieve the density

specified or shown on the Drawings. Achievement of the required density shall be

demonstrated by regular routine testing.

11. Where directed by the Project Manager supports to excavation shall be left in position.

3.9 Reinstatement of Unpaved Land 6. The full extent of all working areas whether affected by the Permanent Works or by

Temporary Works and accesses shall be reinstated as soon as possible after completion of

earthworks.

7. Reinstatement operations shall generally comply with the requirements of BS 4428.

3.10 Trees and Woody Planting The title of Clause 3.10 “Trees” is replaced with “Trees and Woody Planting”.

5. All plants to be supplied to BS 3936 Parts 1 to 10 as relevant, BS 4043, and the National Plant

specification, published by the Horticultural Trades Association, to the sizes and specified

types. All plants shall be British grown, preferably from local provenance. Bare-root plants to

only be planted during the months of November – March.

6. Plants to be protected from drying out/water logging/scorch or any other damage whilst

awaiting planting in accordance with the National Plant Specification – Handling and

Establishment.

7. Plants which are not to be planted on day of delivery shall be protected and heeled in - bundles

shall be opened and the plants spread out and heeled into trenches in topsoil with the entire

root systems in full contact with the soil, and kept thoroughly watered.

8. All native transplants, trees and shrubs are to be protected with green laminate Tubex

Shelterguards for trees or similar approved. Guards for all trees are to be cut from roll to

comfortably suit furnished tree diameter. Softwood stakes. Install in accordance lightly firm

the soil around the base of the plant until it is stable and level with the surrounding ground.

9. All plants shall be thoroughly watered immediately after planting but prior to mulching. Bare

root transplants and feathered trees shall be dipped in Seanure Root Dip anti-desiccant and

MicorForce Whip Dip mycorrhizal root dip or similar approved all to manufacturer’s instructions prior to planting.


10. Bare root transplants to be ‘T’ notch planted

11. All tree surgery or trimming shall only be carried out by a Contractor approved by the

Arboricultural Association and shall be approved by the Project Manager.

12. No trees or shrubs shall be pruned or cleared from site until setting-out work in the relevant

area has been completed, unless such clearance is itself necessary for completion of setting

out and has been explicitly approved by the Project Manager.

13. Prior to any pruning or felling operations, all specimens affected shall be clearly marked by

means of an easily visible band of paint, and such markings shall be approved by the Project

Manager as "essential" before such operations are undertaken.

14. Where trees are specified as requiring uprooting, the resulting holes shall be filled with

suitable excavated material, which shall be compacted to the same dry density as that of the

adjoining ground.

15. The Contractor's method of working and use of constructional plant shall be such that trees

and bushes to be retained are not jeopardised, (e.g. roots crushed or branches damaged)

except that necessary pruning or lopping may be carried out, subject to the Project Manager's

express approval, in accordance with clause 3.10.5.

16. Mature trees on the site may be protected by a Tree Preservation Order. The Contractor shall

ascertain the application of such an order and comply with it.

3.12 Land Drains 6. Where land drains cannot be reinstated the Project Manager will give instructions for their

permanent replacement.

7. The Contractor shall make every effort to ensure that all land drains intercepted by the line of

the haul road laid under the Contract are identified and reinstated. In this respect the

Contractor shall liaise with the landowners/tenants to establish known positions of land drains

or likely drainage patterns before beginning excavation work.

8. A half round class D uPVC pipe of an internal diameter at least as great as that of the drain and

1200mm longer than the trench width shall be laid to bridge the trench and shall be

adequately jointed to the severed laid drain at each end. The half round pipe shall be lined

with clay drainage tiles compatible with the internal diameter of the drain. These pipes and

tiles will be supplied by the Contractor.


3.13 Filling above Ground This section replaces 3.13 clauses 1 and 2.

Filling for Flood Defences and Flood Embankments (Infrequently Wetted) 1. Fill material to for Flood Defences and Flood Embankments shall conform with the

requirements of the Manual of Contract Documents for Highway Works Volume 1

Specification for Highway Works Series 600 Earthworks. Fill material shall be as defined in

Table 6/1 as Class 2C (Stony Cohesive material - General Fill) and compacted in accordance

with Table 6/4 Method 2. The plasticity index as determined by the relevant shall not exceed

35%. Specific criteria for Flood Defences and Embankments are given below in Table 5

Table 5| Placed Properties of Flood Defences and Flood Embankments

Undrained

Shear

Strength

Atterburg

Limits

Dry Density Moisture

Content

Grading

Sieve Size

Percentage by mass

passing the size shown

Class 2C

100 kN/m2

Class 2C

Plastic Index

<35%

Class C2

1850kg/m3

Class C2

Optimum

+1% to

Optimum

+4%

Class C2

125mm 100

2mm 15-80

63microns 18-80

2 All materials used in the works shall be free from leachates which are harmful to the natural

environment of the site. Fill materials shall be free from Rhizomania and other diseases and

also from unwanted plant species. The Contractor shall provide, for the Engineer's approval,

a leachate analysis of all material required for the works. The Contractor shall obtain this

analysis from an approved independent testing laboratory.

3. The Contractor shall employ a competent earthworks supervisor who shall ensure that the

embankment fill materials are conditioned and compacted in accordance with the

requirements of the Specification. This supervisor shall have a specialist supervisory role and

shall be provided in addition to the normal site supervision team and shall not be a plant

operator or working ganger/labourer.

4. Filling for flood defences and flood embankments shall be compacted in layers, not exceeding

200mm thickness, to achieve a density in the permanent works of 95% of the Optimum

Proctor Dry Density for the material 98% of its undisturbed density at its original moisture

content before excavation.

5. Topsoil shall be stripped and all vegetation removed from all areas which are to receive filling.

6. Excavation to the final surface for the foundation of earth structures and flood defences and

flood embankments, including key trenches, shall be carried out immediately before the

commencement of filling.

7. No frozen or ice bearing material shall be used in construction of flood defences and flood

embankments. Filling shall cease if the air temperature falls below -1C.

8. No topsoil or fill materials shall be removed from the site without the permission of the

Engineer.


9. The Contractor shall arrange for an approved independent testing laboratory with NAMAS

accreditation to undertake soils tests to demonstrate compliance with the specification.

10. Testing shall be carried out in accordance with BS 1377: 12, at a rate of two samples per

500m; of fill, one taken before importation/excavation and one after compaction. Tests

required shall be as itemised in the Bills of Quantities. In addition, the Contractor shall prepare

a test panel at the commencement of each construction period. The test panel shall comprise

the full width of the embankment and extend a minimum of 50m along the embankment. For

each layer of fill the Contractor shall record the plant used and the number of passes. The

Contractor shall take and test sufficient samples to ensure that compaction and other

requirements contained in the specification are met. The Contractor shall not be permitted

to carry out further work until the specified criteria have been met.

11 Assuming that the test results are not to the satisfaction of the Engineer then the Contractor

shall prepare further test panels at a second location agreed with the Engineer until the

Engineer is satisfied with the results. This shall be at the Contractor’s expense. If the

Contractor changes his source of material or methods of compaction the Contractor shall

undertake further test panels to establish the compactive effort require to meet the

specification. This shall be at the Contractor’s expense.

12. Undrained shear strengths shall be taken by the Contractor using a portable shear vane in the

presence of the Engineer's Representative. An average of four readings over an area of one

square metre of the foundation or of the embankment being formed shall be considered as

representative of the strength of the material. The Contractor shall keep a detailed record of

the vane tests which should be made available to the Engineer's Representative. The tests

shall be carried out at intervals not exceeding 50 metres along the embankment at foundation

level and at 600 millimetre intervals vertically.

13. The tolerance for levels of filling measured at the end of the Defects Correction Period shall

be the design levels -0mm +75mm.

General Fill 14 Material which complies with the definition of a cohesionless material, shall be accepted as

suitable material for use as General Fill provided that it can be compacted to the densities

required in the specification.

15 Unsuitable material is defined as material which is unsuitable for use as General Fill.

Unsuitable fill reclamation material includes, but not limited to the following:

• Material which complies with the definition of a cohesive material.

• Perishable and organic materials

• Materials containing scrap and rubbish

• Material containing particle sizes greater than 100mm

16 Cohesive material includes all fine-grained soils which exhibit cohesion properties, such as

clayey or silty soils, having a Liquid Limit exceeding 30 or a Plasticity Index exceeding 8,

determined in accordance with ISO/TS 17892-12:2004. Soils containing 15% or more fines that

pass through a 63 micron sieve, are also included in this category.

17 Cohesionless material includes all relatively free-draining granular material such as sands or

gravels which contain less than 15% of fines that will pass through a 63 micron sieve.


18. All imported materials used in the works shall be free from leachates which are harmful to the

natural environment of the site. Fill materials shall be free from Rhizomania and other

diseases and also from unwanted plant species. The Contractor shall provide, for the Project

Manager's approval, a leachate analysis of all material required for the works. The Contractor

shall obtain this analysis from an approved independent testing laboratory.

19. The Contractor shall employ a competent earthworks supervisor who shall ensure that the fill

materials are conditioned and compacted in accordance with the requirements of the

Specification. This supervisor shall have a specialist supervisory role and shall be provided in

addition to the normal site supervision team and shall not be a plant operator or working

ganger/labourer.

20. Filling shall be compacted in layers, not exceeding 200mm thickness, to achieve a density in

the permanent works of 95% of the Optimum Proctor Dry Density for the material 98% of its

undisturbed density at its original moisture content before excavation.

21. Topsoil shall be stripped and all vegetation removed from all areas which are to receive filling.

22. Excavation to the final surface for the foundation of earth structures and embankments,

including key trenches, shall be carried out immediately before the commencement of filling.

23. No frozen or ice bearing material shall be used in construction of fill. Filling shall cease if the

air temperature falls below -1oC.

24. No topsoil or fill materials shall be removed from the site without the permission of the Project

Manager.

25. The Contractor shall arrange for an approved independent testing laboratory with NAMAS

accreditation to undertake soils tests to demonstrate compliance with the specification.

26. Testing shall be carried out in accordance with BS 1377 : 12, at a rate of two samples per

500m3; of fill, one taken before importation/excavation and one after compaction. For each

layer of fill the Contractor shall record the plant used and the number of passes. The

Contractor shall take and test sufficient samples to ensure that compaction and other

requirements contained in the specification are met.

27 Assuming that the test results are not to the satisfaction of the Project Manager then the

Contractor shall prepare further test panels at a second location agreed with the Project

Manager until the Project Manager is satisfied with the results. This shall be at the

Contractor’s expense. If the Contractor changes his source of material or methods of

compaction the Contractor shall undertake further test panels to establish the compactive

effort require to meet the specification. This shall be at the Contractor’s expense.

28. Undrained shear strengths shall be taken by the Contractor using a portable shear vane in the

presence of the Project Manager's Representative. An average of four readings over an area

of one square metre of the foundation or of the embankment being formed shall be

considered as representative of the strength of the material. The Contractor shall keep a

detailed record of the vane tests which should be made available to the Project Manager's

Representative. The tests shall be carried out at intervals not exceeding 50 metres along the

embankment at foundation level and at 600 millimetre intervals vertically.


29. The tolerance for levels of filling measured at the end of the Defects Correction Period shall

be the design levels -0mm +75mm.

30. The surface of any fill layer which has been rolled smooth by the action of traffic or the

compaction process shall be scarified to loosen the surface to a depth of 50 mm immediately

prior to placing the next layer; if the surface has dried out it shall be wetted and blended to

the correct uniform moisture content throughout the fill.

31. Where the Contract requires the placing of different types of fill in separate zones, the

Contractor shall carry out the work so as to prevent mixing the different types of fill. Should

any mixing occur then such mixed material shall be removed from the Site and replaced with

fresh approved material.

Rock Materials for use in Rivers 32 Rock materials within the Contract are defined as follows:

• Channel Dressing Material is small rock, stone and sand which is used to fill the interstice

within the channel bed materials and forms the mobile element of the bed of the

watercourse.

• Channel Bed Material is rock and stone used in the channel bed and on channel sides

which forms the firm and permanent bed of the river channel

• Scour and Erosion Protection materials is rock material used at specific locations on the

sides channel and embankments to mitigate the risks of erosion and scour.

• Slabstones are individual large flat rocks used within the river channel to form steps and

other features

• Blockstone are dressed blocks roughly cuboid in shape

• Boulders are individual large irregular rocks used within the river channel to form features

which creates irregular and changing flow paths.

33 Prior to the placement of any material, the Contractor / Sub- Contractor shall establish

construction control markers clearly visible and understandable to workmen placing

materials. As a minimum, these controls shall delineate the horizontal limits and the finished

elevations of the channel bed materials, scour protection and slabstones. The bed shall be

excavated to the required grades and lines as indicated on the drawings.

34 Channel bed material, scour and erosion protection material shall be placed and spread

uniformly on the existing, excavated, or prepared bottom to the depths and limits indicated

on the drawings by an approved means and method to minimise segregation and to produce

a reasonably well graded compact mass of stone.

35 Channel bed material, scour and erosion protection material shall be placed to a full zone

thickness in one operation, in a manner which avoids displacing or placing undue impact force

on the underlying material and supporting sub-soils.

36 Final finish of slope shall be done as the rock is placed.


Rock Materials for use in Revetments and Breakwaters 37 Prior to the placement of any material, the Contractor / Sub- Contractor shall establish

construction control markers clearly visible and understandable to workmen placing

materials. As a minimum, these controls shall delineate the horizontal limits, both toe and

shoulder lines, and the finished elevations of the core material, underlayer stone, scour

protection and armour stone. The bed shall be excavated to the required grades and lines as

indicated on the drawings.

38 The construction shall proceed in such a manner that the core, filter, scour protection and

underlayer material shall be protected from wave action and high currents at all times. In the

event that the base, core, filter or underlayer is damaged or damage is caused to the

completed section, the damaged portion shall be replaced or reshaped.

39 Material used for temporary structures to protect the exposed ends of the revetment and

breakwater shall be removed after the need has ended. The material removed may be

incorporated into the required permanent construction provided it satisfies the provisions of

this section of the specification.

40 Scour protection, base and core material shall be placed and spread uniformly on the existing,

excavated, or prepared bottom to the depths and limits indicated on the drawings by an

approved means and method to minimise segregation and to produce a reasonably well

graded compact mass of stone. The finished surface of the base and core shall be free draining.

41 Rock for filters shall be placed to the limits indicated on the Drawings by an approved method

to produce a well graded compact mass. Rearranging of individual stones may be required to

achieve this result. Filters shall be placed to a full zone thickness in one operation, in a manner

which avoids displacing or placing undue impact force on the underlying material and

supporting sub-soils.

42 All rock armour and rip rap shall be randomly and individually placed in layers by equipment

suitable for lifting and manipulating rock of the size specified. Dragline buckets and skips shall

not be used for placement of rock. The rock shall be placed in a manner which avoids

displacing underlying materials, placing undue impact forces on underlying materials, and

which minimises chipping of rock armour. Each rock shall be selected as to shape and weight

specified and shall be placed in such a manner as to obtain firm contact with the maximum

number of adjacent rock, thereby providing the best possible stability, interlocking, and keying

of the armour.

43 Rehandling of individual stones after initial placement may be required to achieve the above

requirements. Placement of rock armour rip rap shall begin at the bottom of the slope.

Casting or dropping of stones over a distance of 300mm or greater, or moving by drifting or

manipulating down the slope will not be permitted. Rectangular stone shall be placed with

its long axis perpendicular to the side slopes.


44 Where core materials are placed by clamshell, dragline, or other similar equipment, the rock

shall not be dropped from a height exceeding 0.5m above the existing surface or previously

placed materials. When bottom dump scows and self-unloading vessels are used with the

vessel in motion along the centreline of the structure, the material shall be dropped as near

to and directly over its final location as possible.

45 Placement of rock by any method which is likely to cause segregation of the various sizes shall

not be permitted. Unsegregated rock shall be lowered in a bucket or container and placed in

a systematic manner directly on the underlying rock. The larger rock for underlayer shall be

well distributed throughout the mass and the completed underlayer shall be free from pockets

of smaller rock or clusters of large rock. The placement of rock shall begin at the bottom of

the slope and proceed upward. Casting or dropping of stone over a distance of 0.5m or greater

or moving rock by drifting and manipulating down the slope will not be permitted.

46 Final finish of slope shall be done as the rock is placed. Where rock is to be placed below mean

high water, the Contractor / Sub-Contractor shall plan and conduct his operations in such a

manner as will result in a minimum loss of underlayer material due to wave action. Filter rock

shall be dressed and rearranged while placing the armour rock and any additional material

shall be added, if measurements indicate such to be necessary.

47 Any temporary construction roadway or fill which the Contractor / Sub- Contractor may elect

to build, to facilitate his operations shall be removed and the surface restored.

48 The Contractor / Sub- Contractor shall at all times ensure that floating plant displays requisite

and adequate daymarks and lights, when navigating, working or at anchor, in accordance with

local and national regulations and appropriate international maritime conventions. All items

of marine plant shall observe normal navigational conventions in and around the site. Care

shall be exercised when in proximity to other marine craft and, in particular, when adjacent

to leisure craft or within areas currently used for recreation. A speed restriction of 3 knots will

be observed and care shall be taken to preserve the lagoon bottom and edge structures as

constructed until handover of the works.

49 Any item of plant or equipment lost overboard, sunk or otherwise abandoned prior to or

during the works shall be raised and removed from the site immediately. At the completion

of the contract the Contractor / Sub- Contractor shall remove all anchors, chains, wires and

any other equipment plant or materials introduced by him.

Geotextiles & Geotextile-related Products used to Separate Earthworks

Materials 50 Geotextiles and geotextile-related products shall conform to the requirements of the product

standard BS EN 13251. A Declaration of Performance for each product stating compliance with

BS EN 13251 and the required levels of performance shall be submitted to the Project

Manager prior to their placement in the works.


3.17 Site Clearance and Surface Stripping 1. All areas of the Site specified or marked on the Drawings for clearance or from which material

is to be excavated or upon which filling is to be deposited shall be cleared to the extent

required by the Project Manager of all buildings, walls, gates, fences and other structures and

obstructions and of all bushes, hedges, trees, stumps, roots and other vegetation except for

trees marked for preservation.

2. Special requirements concerning trees are shown in Clause 3.11.

3. Hedges shall be removed only with the Project Manager's permission and then only to the

minimum extent necessary for working space or access. The Contractor shall take every

precaution to avoid damage to other hedges which are not to be removed.

4. Materials for reuse in the Works shall be carefully dismantled and suitably stored by the

Contractor until they are incorporated into the Works.

5. Materials not for reuse in the Works shall be disposed of by the Contractor off the Site.

6. Where ordered by the Project Manager the top surface including Topsoil if any shall be

stripped, to such depths and over such areas as he may direct, as a separate operation prior

to any further excavation which may be required.

3.18 Trial Holes 1. The Project Manager may direct that trial holes shall be excavated in advance of other

excavation to such dimensions and depths as he shall order to determine information required

by him.

2. The Contractor shall arrange for the refilling and reinstatement of trial holes to be carried out

immediately the required information has been obtained. The holes shall be refilled with

approved material deposited and compacted in layers to the same dry density as the adjoining

soil.

3.19 Survey of Final Ground Levels 1. The Contractor shall organise and jointly perform with the Project Manager a final survey of

all ground levels affected by the Works. The methods adopted for taking and recording such

surveys shall be agreed in advance with the Project Manager and shall as far as possible be

referred to the same datum points as are used for the initial surveys.

3.20 Maintenance of Landscaping 1. When new grass has grown to 75 mm high it shall be given an initial cut (topping) with a roto-

scythe to leave 25 mm to 50 mm of growth.

2. The young grass shall be subsequently kept free from weeds and shall be mown as necessary

to achieve a consistent sward with length not exceeding 75mm. Any bare patches shall be

repaired (with imported topsoil if required), treated with fertilizer and reseeded with the

appropriate seed mixture.

3. The Contractor shall regularly inspect the Site and shall carry out all works necessary to

promote and maintain the new grass until the end of the Defects Correction Period.

4. All works shall be in accordance with the recommendations of BS 4428.

39 SECTION 4 - Concrete and Formwork | Client: Ribble Rivers Trust

SECTION 4 - CONCRETE AND FORMWORK

4.1 Supply of Information 2. The Contractor shall satisfy the Project Manager that the arrangements for the production of

concrete are adequate for the proper and timely completion of each concreting operation.

4.2 Initial Testing 3. The Project Manager may instruct the Contractor to arrange for the calibration and testing of

the batching plant, whether ready-mix or on-Site, more frequently than called for by Clause

4.5 of BS 5328: Part 3. The Contractor shall do everything necessary to comply with this

instruction and shall provide every additional facility which the Project Manager may require

for the supervision of the batching, mixing and transporting of concrete.

4. The Contractor shall notify the Project Manager not less than 14 days before the start of any

tests or trials which are required and shall then allow sufficient time for the proper execution

of such tests and trials having regard to the requirements of Clause 4.3.2.

4.5 Transporting, Placing and Compacting

Notification and approval 6. Before any concreting operations commence, the Contractor shall institute a "Pour Card"

system in which a card is made out for each pour of concrete and is signed by or on behalf of

the Contractor indicating that each part of the work has been checked and approved by a

responsible person on the Contractor's site staff.

7. The Pour Card shall give the following information:-

• Location of pour

• Date and time of pour

• Concrete mix

• Placing method, pump or skip etc

• Approximate quantity

8 The Pour Card shall include spaces to signify approval at each of the following stages:-

• Prepared surfaces on or against which concrete is to be placed.

• Reinforcement.

• Embedded items and formwork.

• Arrangements for placing concrete.

• Curing procedures.

9 The Contractor shall complete all the details on the notification form and submit a copy to the

Project Manager 24 hours before the intended time of each pour. No concrete shall be poured

until the Project Manager has inspected and approved the surfaces upon which the concrete

is to be placed, the formwork, the reinforcement and any other conditions which may

influence the pour.

10. Sufficient resources shall be provided by the Contractor to ensure that the concreting

operation can be continuous and in accordance with all the other requirements of the

Specification. Should the Project Manager consider that the resources of men or plant are or

are likely to be inadequate, he may withdraw his approval to proceed.


Placing of concrete - general 11. Concrete shall be carefully placed in horizontal layers which shall be kept at an even height

throughout the work. Concrete shall not be allowed to slide or flow down sloping surfaces

directly into its final position but shall be placed in its final position from skips, trucks, barrows,

down pipes or other placing machine or device or, if this is impossible, it shall be shovelled

into position, with care being taken to avoid separation of the constituent materials. Concrete

placed in horizontal slabs from barrows or other tipping vehicles shall be tipped into the face

of the previously placed concrete.

12. Concrete dropped into place in the work shall be dropped vertically. It shall not strike the

formwork between the point of its discharge and its final place in the work. Concrete shall

not be dropped freely through a height greater than 1.5 metres. Chutes and conveyor belts

shall be so designed that there is no segregation or loss of mortar and shall be provided with

a vertical tapered down pipe or other device to ensure that concrete is discharged vertically

into place.

13. Where a lift of concrete is built up in layers, each layer shall be properly merged into the

preceding layer before initial set takes place.

14. When pneumatic placers are used, if the end of the placer pipe is not equipped with an energy

absorbing device it shall be kept as close to the work as practicable. Mortar or water used at

the beginning or end of a run shall be discharged outside the formwork.

15. When pumps are used, the end of the supply pipe shall be kept immersed in the concrete

during placing to assist compaction. Mortar or water used at the beginning or end of a run

shall be discharged outside the formwork.

16. Concreting in the vicinity of water stops and the like shall be carried out with care to ensure

that the water stops, etc. do not bend or distort during placing and compacting the concrete.

17. Concrete placing shall not commence until any water which has collected within the formwork

has been removed.

Placing underwater 18. Where any concrete is to be placed in water, the Contractor shall obtain the written

permission of the Project Manager before commencing the work.

19. Concrete shall not be placed in running water nor shall concrete be allowed to fall through

water. Concrete shall be placed in water only by means of a bottom-opening watertight box

or a tremie of a type approved by the Project Manager. Bottom-opening boxes shall not be

opened until they are resting on the work, and the lower ends of tremies shall always be kept

below the surface of freshly placed concrete.


Compaction 20. Vibrators shall be inserted into the un-compacted concrete vertically and at regular intervals.

The depth of un-compacted concrete shall not exceed 450 mm where internal vibrators are

used or, 300 mm in all other cases. Where the un-compacted concrete is a layer above freshly

compacted concrete the vibrator shall be allowed to penetrate vertically for about 100 mm

into the previous layer. In no circumstances shall vibrators be allowed to come into contact

with the reinforcement or formwork, nor shall they be withdrawn quickly from the mass of

concrete but shall be drawn back slowly so as to leave no voids. Internal type vibrators shall

not be placed in the concrete in a random or haphazard manner nor shall concrete be moved

from one part of the work to another by means of the vibrators.

21. Vibrating screeds shall be used only on slabs less than 225 mm thick. Immersion type vibrators

shall not be used to compact slabs less than 225 mm thick.

4.6 Concreting in Cold Weather 3. Prior to concreting in cold weather, the Contractor shall submit to the Project Manager details

of the precautions he proposes to take to protect the concrete from the effects of low

temperatures. No concreting in cold weather shall be take place until the proposed measures

have been approved by the Project Manager.

4.7 Concrete Temperature 3. Where the concrete is to be used in a structure designed to retain an aqueous liquid, the

temperature shown in Clause 4.14.3 shall be reduced from 32_C to 25_C.

4.8 Curing 4. Curing methods may include:-

• water sprays in continuous operation;

• covering with Hessian or similar absorbent material, or sand, kept constantly wet;

• thorough wetting followed by covering with a layer of waterproof fabric kept in contact

with the concrete surface; or

• the application of an approved non-staining liquid membrane which is either self

removing or easily removed following the curing period. The liquid shall be applied to

formed surfaces immediately after stripping the formwork.

5. Liquid curing membranes shall not be used on a Screeded Finish or where laitance is to be

removed and aggregate exposed to provide a satisfactory bond for placing further concrete

or mortar screeds, or where it may spoil the finished appearance of an exposed surface.

4.10 Construction of Formwork 7. Formwork shall have openings for the inspection of the inside of the formwork and the

removal of water which can be easily closed during concrete placing.

8. The finished appearance of the entire structure and adjoining structures shall be considered

when planning the pattern of joint lines caused by formwork and construction joints to ensure

continuity of lines.

9. Unless otherwise shown on the Drawings or instructed by the Project Manager, all arris of 90_

or less, other than on the nosings to steps, shall have 50 mm x 50 mm chamfers produced by

securely fixing timber fillets to the inside of formwork.


4.11 Cleaning and Treatment Of Forms 3. Release agents shall be non-staining.

4. Surface retarding agents shall not be used unless specifically approved by the Project

Manager.

4.14 Cutting and Bending of Reinforcement 3. Ready cut and bent reinforcement shall be obtained only from suppliers holding valid

Certificate of Approval for the fabrication of steel reinforcement issued by the UK Certification

Authority for Reinforcing Steels (CARES).

4.15 Fixing of Reinforcement 4. No part of the reinforcement shall be used to support formwork, access ways, working

platforms or placing equipment, or for the conducting of an electrical current.

4.18 Welding of Reinforcement 2. Reinforcement which is specified to be welded shall be welded in accordance with the

requirements of BS 5135 and the recommendations of the manufacturer. The welding

procedure established by successful test welds shall be maintained and no departure from

this procedure shall be permitted.

3. Following the establishment of a satisfactory welding procedure, each welder to be employed

on the Works shall carry out welder performance qualification tests on reinforcing bars of the

same metal and size as those on the Works. The requirements of BS 4871 shall be observed.

4. Details of welding procedure and welder qualification tests shall be reviewed by the Project

Manager before welding of reinforcement commences.

5. Tacking welding or other welds in positions other than those shown on the Drawings shall not

be permitted, unless specifically authorised by the Project Manager.

4.19 Built-In Items 3. Pipes and other items passing through concrete structures shall wherever practicable be built

into the structure as work proceeds, having been installed and connected to the remainder of

the system to ensure proper fit prior to the start of any concreting. Where this procedure

cannot be adopted, holes shall be formed for such items to allow them to be built in later

along with or after installation of the remainder of the system. Such holes shall be of size and

shape sufficient to permit proper placing and compaction of concrete or grout. The surfaces

of the holes shall be treated as construction joints.

4. In no case shall any pipe with flanged joints be concreted in until its accurate fit with other

pipework has been checked and it has been secured in position.

5. Concrete used for building-in shall be of the same grade as the surrounding concrete, except

that the mix shall also incorporate an approved expanding additive, complying where relevant

with Clause 2.1.11 and used with due regard to the manufacturer's instructions. Concrete

shall be placed and compacted by methods which will avoid moving or damaging built-in

items.


4.20 Construction Joints 8. A construction joint is defined as a joint in the concrete introduced for convenience in

construction at which special measures are taken to achieve subsequent continuity without

provision for further relative movement.

9. Construction joints shall be located so as not to impair the strength of the concrete. Rebates,

keys, or notches shall be formed and waterstops inserted as the Project Manager may require.

10. The position of construction joints and the size of the formwork panels shall be so co-

ordinated that where possible the line of any construction joint coincides with the line of a

formwork joint and that in any case all construction joint lines and formwork joint lines appear

as a regular and uniform series.

11. For all exposed horizontal joints and purposely inclined joints, a uniform joint shall be formed

with a batten of approved dimensions to give a straight and neat joint line.

4.21 Surface Finishes Produced Without Formwork 6. The type of finish on permanently exposed surfaces other than road slabs shall be Steel Trowel

Finish.

7. The addition of dry cement, mortar or water shall not be permitted during the operations

detailed in Clauses 4.28.1 to 4.28.3.

4.22 Surface Finishes Produced with Formwork

Superior Finish 7. The surface is obtained by lining the formwork with large panels of non-staining material with

a smooth and unblemished surface such as sanded plywood or hard compressed fibreboard

arranged in a uniform pattern and fixed to the back formwork with oval nails. All the joints

between the panels and nail holes shall be filled and sanded flat such that the concrete surface

so produced is smooth.

General

8. Except where otherwise shown on the Drawings or elsewhere in the Specification, the type of

finishes required at each location shall be as tabulated below:-

Location Finish

• Aqueous liquid retaining faces Fair worked

• Inside of structures (other than above) Fair

• External faces of structures other than roads:-

a. Below a level 0.3 m below finished ground level Rough

b. Above a level 0.3 m below finished ground level Fair worked

• Where the face does not extend above ground level

a. Above a level 0.3 m below finished ground level Fair

b. where the face does extend above ground level Rough

9. Workmanship in formwork and concreting shall be such that concrete shall normally require

no making good, surfaces being properly compacted, smooth and with no irregularities

outside the permitted tolerances.


10. If any portion of the facework should prove unsatisfactory on removal of the formwork, the

necessary remedial measures shall be agreed with the Project Manager immediately. No

making good shall commence until after such agreement. Measures may include:-

• For fins, pinhole bubbles and surface discolouration the surface may be rubbed down with

sacking immediately after removal of formwork and prior to curing.

• Abrupt irregularities may be rubbed down using a Carborundum stone and water after the

concrete is fully cured.

• Defects may be cut out to a regular dovetail shape at least 75 mm deep and refilled with

concrete over steel mesh reinforcement sprung into the dovetail.

• Defects may be cut out and made good with an epoxy mortar applied strictly in accordance

with the manufacturer's recommendations.

11 No plaster ring of concrete surfaces will be allowed. Where, in the opinion of the Project

Manager, the defect is too extensive to permit satisfactory repair, from the point of view of

either structural integrity or appearance, the concrete containing the defect shall be broken

out and replaced.

12. Any concrete, the surface of which has been treated without the consent of the Project

Manager shall be liable to rejection.

4.24 Tie Bolts for Formwork 6. The distance of 50mm referred to in Clause 4.31.1 applies to reinforced concrete. For

unreinforced concrete the distance shall be 150 mm.

7. Ties for use in structures designed to retain an aqueous liquid shall incorporate a diaphragm

not less than 75 mm dia. and not less than 4 mm thick welded to the mid-point of the tie,

designed to prevent water passing along the tie.

4.25 Tolerances for Concrete Surfaces 2. Delete the table in Clause 4.33.1 and replace with the following:-

MAXIMUM TOLERANCE (mm)

Surface finish Line and level Gradual irregularity Dimension

WITHOUT FORMWORK

Screeded

Wood float

Steel trowel

± 12

± 6

± 6

± 6

± 3

± 3

-

-

-

WITH FORMWORK

Rough

Fair

Fair worked

Superior

± 12

± 6

± 6

± 3

± 6

± 6

± 6

± 3

± 12

± 6

± 6

± 3


Notes

a. "Line and level" and "dimension" are the lines, levels and cross-sectional dimensions

shown on the Drawings.

b. "Abrupt irregularities" include, but shall not be limited to, offsets and fins caused by

displaced or misplaced formwork, loose knots and other defects in formwork materials,

and shall be tested by direct measurement.

c. "Gradual irregularities" shall be tested by means of a straight template for plane surfaces

or the suitable equivalent for curved surfaces, the template being 3.0 m long for unformed

surfaces and 1.5 m long for formed surfaces.

4.29 Submissions by the Contractor - Concrete and Formwork

General 1. The following list of submissions required from the Contractor in relation to concrete work

and formwork includes many which are described in other clauses of the Specification.

Certificates 2. Manufacturers' and suppliers' certificates of compliance with relevant standards shall be

provided in respect of the following materials:

• cement

• aggregates

• admixtures

• jointing materials

3. The Contractor shall also furnish

• details of any proposed ready-mixed concrete supplier

• calibration certificates for the weighing and dispensing devices on batching and mixing

plant

• certified test results of any subsequent tests carried out on the foregoing materials, on

water, and on fresh and hardened concrete.

Samples 4. The Contractor shall provide samples of all the foregoing materials. Approved samples shall

be kept in suitable containers, properly labelled, and stored on Site for reference.

Concrete mixes 5. The Contractor shall submit mix design details for all grades of concrete required for the

Works.

Formwork and reinforcement

6. Submissions required from the Contractor in relation to formwork and reinforcement shall

include the following where relevant:

• manufacturers' data on accessories and mechanical couplings;

• manufacturers' test certificates for each delivery of steel reinforcement as required by the

relevant quality standard;

• samples of steel reinforcement for testing and layout of construction joints and lifts;

• details of any proposed supplier of ready cut and bent reinforcement.

46 4.30 Site-Mixed Concrete | Client: Ribble Rivers Trust

Records of concreting 7. The Contractor shall submit daily returns in respect of all concrete placed during the previous

day. The returns shall detail:

(a) in respect of each grade of concrete -

• the number of batches mixed/deliveries received

• the number of batches and the total volume of concrete placed

• the number of batches/quantity wasted or rejected

• the weight of cement used, and

(b) in respect of each location in the Works -

• the position of the pour (e.g. bay or lift reference number)

• the grade of the concrete placed

• the total volume of concrete placed and the number of batches used/deliveries

received.

8. In addition, the Contractor shall maintain an accurate and up to date record showing dates,

times, weather and temperature conditions when each part of the Works was concreted. The

record shall be available for inspection by the Project Manager at all times.

9. Results of all tests on concrete shall be recorded, identified with the parts of the Works to

which they relate and copied to the Project Manager without delay. The procedure for

sampling and testing concrete shall be as specified in Clause 4.35.

Other submissions 10. Where relevant to the Works, the Contractor shall submit his proposals for special measures

for dealing with particular circumstances (e.g. concreting in hot/cold weather).

4.30 SITE-MIXED CONCRETE

Mechanical mixing

1. The weighing and water-dispensing mechanisms shall be maintained in good order. Their

accuracy shall be maintained within the tolerances described in BS 1305 and checked against

weights and volumes when directed.

2. The weights of cement and each size of aggregate as indicated by the mechanisms employed

shall be within a tolerance of ± 2% of the respective weights per batch agreed by the Project

Manager. The weight of the fine and coarse aggregates shall be adjusted to allow for the free

water contained in them. The water to be added to the mix shall be reduced by the quantity

of free water contained in the fine and coarse aggregates, which shall be determined by the

Contractor immediately before mixing begins, and further as may be directed.


3. Unless otherwise approved, concrete shall be mixed in a batch type mixer manufactured in

accordance with BS 1305 or in a batch type mixer a specimen of which has been tested in

accordance with BS 3963 and having a mixing performance within the limits of

BS 1305:Table 6. Where appropriate the batch capacity, method of loading, mixing time and

drum speed shall conform to the details furnished in accordance with the requirements of

BS 3963 for the mix which corresponds most closely to the mix proportions being used. The

mixing blades of pan mixers shall be maintained within the tolerances specified by the

manufacturer of the mixer and the blades shall be replaced when it is no longer possible to

maintain the tolerances by adjustment.

4. Mixers which have been out of use for more than 30 minutes shall be thoroughly cleaned

before any fresh concrete is mixed. The first batch of concrete through the mixer shall contain

only two-thirds of the normal quantity of coarse aggregate. Mixing plant shall be thoroughly

cleaned before changing from one type of cement to another.

5. Concrete shall not be mixed when the air temperature in the shade is below 3_C unless special

precautions are taken which have been approved by the Project Manager. No frozen material

or materials containing ice shall be used.

6. During hot weather the Contractor shall ensure that the constituent materials of the concrete

are sufficiently cool to prevent the concrete from stiffening in the interval between its

discharge from the mixer and compaction in its final position.

Hand mixing 7. If approval for the mixing of small quantities of concrete by hand is given, mixing shall be done

on a clean, level, non-porous surface, the material being carefully turned over twice in a dry

state and three times after the addition of water. Cement shall be increased by 10% in hand

mixing and not more than 0.5 m³ shall be mixed at one time.

4.31 Applied Finishes 1. Where an applied finish is to be used the concrete shall have a wood float finish or a screeded

finish but to the tolerances required for a float finish. Approved adhesives and materials shall

be applied in accordance with the manufacturer's instructions. Faces shall be treated in one

application per day and joints shall be made where directed. After application no remedial

treatment will be permitted to any face apart from complete reapplication.

4.32 Preparing for Concreting 1. The treatment of forms, reinforcement, construction joints and movement joints prior to

concrete are detailed in Clauses 4.18, 4.23, 4.27 and 4.43 respectively. Other man-made items

to be placed in contact with concrete shall be free from any substance which might adversely

affect the item or the concrete chemically or unintentionally reduce the bond.

2. Where concrete abuts against earth or other materials liable to become loose or to slip, the

Contractor shall take steps to prevent any such loose material falling onto the surface of the

concrete. These precautions shall be subject to the Project Manager's approval which shall

be obtained prior to concreting.

3. Before placing concrete the Contractor shall remove from the surface of the foundations or

previously placed concrete, all oil, loose fragments of rock, earth, mud, timber or other debris

and any standing water.


4. Where specified and elsewhere as ordered by the Project Manager, the excavated surfaces on

which concrete is to be placed shall be covered with blinding concrete not less than 75 mm

thick, waterproof building paper, or polythene sheeting 0.1 mm in thickness immediately after

completion of the final trimming of the excavation.

4.33 Fixing of Metalwork to Concrete 1. Where the Drawings show metalwork founded on and fastened to concrete the Contractor

shall use one of the following methods as subsequently detailed:-

Method Description

A. Bolting or screwing the metalwork to plates or angle section with anchors set into the

concrete structure or set into pockets left in the concrete structure.

B. Setting the metalwork into pockets left in the concrete structure with resin grout.

C. Bolting the metalwork to bolts set into the concrete structure or set in pockets or

holes in the concrete structure.

D. Bolting the metalwork to self anchoring epoxy resin fixed bolts placed in drilled holes

or fixing direct with epoxy resin in drilled holes.

E. Building in during construction.

4.34 Sulphate Content of Concrete 1. No concrete shall contain water soluble sulphates as 503 ions totalling more than 4% by mass

of the total cementitious content.

2. Tests for salts shall be carried out in accordance with the following standards:-

• Sulphates in aggregate BS812 Part 118

• Sulphates in mixing water ASJM D516

4.35 Sampling and Testing of Concrete

General 1. The Contractor shall determine the compacting factor and slump of, and where appropriate

the quantity of entrained air in, the freshly mixed concrete by the methods described in BS

1881 on each occasion that a set of test cubes is made and at such other times as the Project

Manager may direct. The compacting factor and slump shall be correlated so that at other

times slump tests may be used in lieu of compacting factor tests.

2. For each grade of concrete, sets of test cubes shall be made for samples taken whenever

required by the Project Manager but at a sampling rate not less frequent than that shown in

the table which forms part of Clause 4.3.7.

3. Each set of cubes shall consist of two cubes and be made from a single sample taken from a

randomly selected batch of concrete. The two cubes making up a set shall be tested 28 days

after manufacture and the average of the two results shall be taken as the test result. The

cubes shall be tested in accordance with BS 1881.


4. Where the Contractor's rate of concreting produces concrete of a particular grade only at very

infrequent intervals, the Contractor shall, on the day of each pour, make sets of cubes from at

least 4 randomly selected samples to ensure that enough representative test cubes are always

available to limit the quantity of concrete at risk as defined in Clause 3.17 of BS 5328: Part 4.

5. The Contractor shall supply all testing apparatus and shall keep on the Site a record of all tests,

identifying them with the parts of the work from which the samples were taken.

Non-compliance of the test results 6. If the mean strength of the concrete as determined from four consecutive tests fails to meet

the requirement of Clause 3.16.2(a) of BS 5328: Part 4, no further concrete from that mix shall

be placed in the Works and the Contractor shall establish the cause of the failure and apply

such remedies as are necessary. The Contractor shall demonstrate by trial mixes and test cube

results that the revised mix is in accordance with the specified requirements.

7. If the mean strength of the concrete as determined from one or more tests fails to meet the

requirements of Clause 3.16.2 of BS 5328: Part 4, the Contractor shall within 24 hours of the

date of test make proposals for agreement with the Project Manager about action to be taken

in respect of all concrete represented by test(s) which has failed to meet the requirements.

The extent of the concrete shall be as defined in Clause 3.17 of BS 5328:

Part 4. The proposals may include, but shall not be limited to, cutting and testing cores.

8. Where the Contractor proposes to cut and test core specimens for the purpose of examination

and testing, the locations from which the specimens are to be cut shall first be agreed with

the Project Manager.

9. Cylindrical core specimens shall be prepared, examined, measured and tested in accordance

with BS 1881 using the preferred methods, ratios and sizes where possible. Prior to

preparation for testing, the specimen shall be made available for examination by the Project

Manager.

10. If the crushing strength of the specimen determined in accordance with BS 1881 is less than

the specified characteristic strength at 28 days or if in the opinion of the Project Manager the

concrete fails to meet the specified requirements in other respects, the concrete in that part

of the Works of which it is a sample shall be considered not to comply with the Specification.

11. Concrete which does not comply with the Specification shall be rejected and shall be broken

out and replaced or otherwise dealt with as agreed with the Project Manager.

4.36 Mechanical Couplings for Reinforcement 1. Where mechanical couplings are shown on the Drawings or are approved for use in other

locations such coupling shall be supplied by an approved manufacturer who shall also supply

the equipment for making the couplings. The Contractor shall demonstrate by tensile tests

on sample joints of all sizes required for use in the Works that the use of the couplings does

not reduce the strength of the parent bars, that completed couplings possess strength not less

than that of the parent bars, and that there is a significant permanent set in the couplings as

the bars are loaded.

2. Mechanical couplings shall be used only with equipment supplied by the coupling

manufacturer.


4.37 Water Stops 1. As far as possible, jointing of water stops on Site shall be confined to making butt joints in

straight runs. Where it is necessary for an intersection, or change of direction, or any joint

other than a butt joint in a straight run, to be made on Site, a preliminary joint, intersection

or change of direction piece shall be made and submitted to such tests as the Project Manager

may require.

2. Flexible water stops shall be fully supported in the formwork, free of nails and clear of

reinforcement and other fixtures. Any water stop which after installation is found to be

damaged shall be removed and replaced.

4.38 Movement and Expansion Joints

General 1. Movement and expansion joints are defined as all joints intended to accommodate relative

movement between adjoining parts of a structure, special provision being made where

necessary for maintaining the water tightness of the joint. The Contractor shall comply with

the instructions of manufacturers of proprietary jointing and capping materials and shall, if

required by the Project Manager, demonstrate that the jointing materials can be applied

satisfactorily.

2. The surface of set concrete in movement joints shall, where so shown on the Drawings, be

painted with two coats of bituminous paint and new concrete shall be placed against it only

when the paint is dry. Expansion joints shall be formed by a separating strip of preformed

joint filler.

3. Caulking grooves shall be provided as shown on the Drawings. At all joints where a caulking

groove is formed, the groove shall be wire brushed immediately prior to caulking and loose

material shall be removed and blown out by compressed air. After the groove has dried it

shall be primed and caulked with joint compound applied in accordance with the

manufacturer's instructions. At all caulked joints a bond breaking tape shall be installed over

the face of the caulking strip.

51 SECTION 5 - Construction of Pipelines, Tunnels & Ancillary Works | Client: Ribble Rivers

Trust

SECTION 5 - CONSTRUCTION OF PIPELINES, TUNNELS & ANCILLARY

WORKS

5.1 Pipe Laying Generally

General 9. Clauses associated with pipelines, tunnels and ancillary works contained in Section 5 of the

specification shall be deemed to include box concrete culverts.

10. Pipelines shall be set out by the Contractor in accordance with the Drawings. The exact

position of pipelines, manholes and chambers shall if necessary be varied on Site with the

approval of the Project Manager after trial holes have been excavated to prove the location

of buried services and other obstructions. Manholes and chambers in private land shall

wherever possible be sited at field boundaries.

11. Pipes shall be laid to even grades for as long a length as possible, irrespective of local changes

of elevation of the ground surface, with a minimum grade of 0.2%. Changes in direction or in

grade of the pipeline shall be carried out by making use of any permissible deflection of joints

between straight pipes or by the introduction of bends where shown on the Drawings.

12. Socket and spigot pipes shall normally be laid with sockets leading. Where the gradient

exceeds 5%, installation shall proceed on an ascending grade. Except as otherwise specified,

pipes shall generally be installed singly and shall not be jointed until after they have been laid.

After laying and jointing, the invert level of each pipe shall be checked before the next pipe is

laid.

13. Unless otherwise specified or shown on the Drawings, the minimum depth of cover to the top

of the pipe barrel shall normally be 1000 mm.

14. Wherever pipes and similar services are buried in the ground a marker tape shall be laid 300

mm above each and every service in the trench. Unless otherwise instructed by the Project

Manager, the location of each pipeline and similar service shall be marked at each field

boundary by means of a marker post.

Crossing existing pipelines and buried cables 15. Where pipelines cross existing pipelines or buried cables particular care shall be taken to avoid

damage to the existing pipelines or cables. The Contractor shall give one month's advance

notice of the work to the owners of the existing pipelines or cables, and shall comply with any

special requirements of the owners for safety or security during progress of the work. The

Contractor shall take such measures as are detailed on the Drawings or are instructed by the

Project Manager to permanently support and protect the existing and new installations.

Crossing watercourses

16. Pipelines crossing watercourses shall, unless otherwise shown on the Drawings, be laid

beneath the watercourse. The pipelines shall be protected as shown on the Drawings. The

top of the protection shall be at least 300 mm below the true cleaned bottom of the

watercourse.

52 SECTION 5 - Construction of Pipelines, Tunnels & Ancillary Works | Client: Ribble Rivers

Trust

5.2 Pipe Bedding 5. The extent of granular bedding and surround shall be as indicated on the Drawings or ordered

by the Project Manager.

6. Recesses shall be formed in the granular bedding to accommodate sockets, collars or other

pipe joints and, if instructed on the Drawings, for the lower part of the pipe barrel. No hard

support blocks shall be used.