good engineering practice at site
DESCRIPTION
Good Engineering Practice at SiteTRANSCRIPT
-
1Good Engineering PracticeAt Sites
C. Material testing
B. Construction tolerances
D. Concrete
E. Detailing
A. Getting ready
-
2A. Getting Ready
a. Study all drawings, report any discrepancies
b. Prepare site layout with temporary facilities & program
c. Set-out centerlines,boundaries & disturbances to existing services
d. Take dated photographs of all adjoining buildings prior to commencement of work at site and afterwards
e. Keep weather records countersigned by the Consultants site representative
f. Prepare shop drawings of critical joints etc.
g. Co-ordinate work & arrange meetings with other contractors
h. Participate in progress & other meetings with Consultants
-
3STEMS STEMS CONSULTANTS (PTE) LTD159, Model Farm Road, Colombo 08
No Name Address Telephone Fax
1
1234
123
1
1
1
A B C123
Lift Suppler
Contractor
Electrical Engineer
Structural Engineers
Services Consultants
Project :PROPOSED 35 STOREY TOWER AT LOT A1 & B3, GALLE ROAD, COLOMBO 03.
Project Data SheetE-mail
Client
Architects \ Lead Consultant
Consultants
a. Prepare project data sheet
STEMS CONSULTANTS (PTE) LTD
159, Model Farm Road, Colombo 08. Building
Date : 18/08/2007 at : 10 .30 am / pm at Site / Office
1 0 Attendance SheetNo Name Organization Signature Tel / Fax
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
PILING PROGRESS MEETING NO
APARTMENT BUILDING
PROPOSED 35 STOREY RESIDENTIAL TOWER WITH 3 STOREY BASEMENT
AT LOT A1 & B3 , GALLE ROAD, COLOMBO 03.
STEMSProject
Prepare an attendance sheet
-
4STEMS ProjectSTEMS CONSULTANTS (PTE) LTD159, Model Farm Road, Colom bo 08. Building
Notes Of Meeting Attended (NOMA) Meeting No: 06Date: 18/08/2007 Time: 10.30 am / pm Venue : Site Office
Notes Taken by: S A Karunaratne
Item Description Action by
APARTMENT BUILDING
PROPOSED 35 STOREY TOWER, LOT A1 & B3, GALLE ROAD, COLOMBO 03
b. Prepare NOMA
c. Furnish copy same day to Head-office
d. Act prior to receipt of official minutes
a. Do not take Notes Of Meetings Attended, NOMAon pieces of paper
STEMS ProjectSTEMS CONSULTANTS (PTE) LTD159, Model Farm Road, Colom bo 08 Client Imperial Tea Exports (Pvt) Ltd, 121A, Biyagama Rd, Peliyagoda
Items to be discussed at First Site Meeting Meeting No:01
Date: 2004 - 11 - 06 Time: 10.30 am / pm Venue : Site Office
Item Action by
(1)
(2)
(3)
(4)
(5)
(6) Names of Ready-Mix suppliers, if to be changed advance notice and furnish details in Item 5
(7) If constituent materials are changed Contractor should furnish test data and compatibility
(8)
(9)
(10)
(11)
(12)
(13)
(14)
(15)
(16)
(17)
(18)
(19)
(20)
(21)
Blending & Warehouse Building, 151, Biyagama Road, Peliyagoda
Construction drawings to be checked by Contractor and inform Consultant if more details are required
Main orthogonal grids to be checked by Consultant after Contractor setout the buildings
Contractor to furnish Consultant a plan of temporary facilities and locations with dimensions
Notes Taken by:
Description
Performance, Advance Payment Bonds and Insurance Cover from Contractor
Mix design, 40 No. Test cube results, material tests and admixtures, extreme care with sand.
Approval of fill material to be used in ground improvements
Approval for concreting.
Test cubes, 06 numbers, 02 for 07 day tests and 04 for 28 days tests, proper identification, proper
moulds, proper storage, curing and due date testing
Cover blocks - Same concrete grade with small chips
Structural Steel fabrication
Consultant's site staff office
Temporary power, telephones, fax, photocopying facilities, water and toilets etc
Typical format of records
Site Instructions and Variation Orders
Master programme and Cash Flow Chart and "S" Curve
Biweekly detailed programme matching with master programme, monthly progress report
Electrical Drawings from Contractor to be checked by Consultant
Date of commencement, Completion date, Time left, Extensions
Site Safety, Accidents at site
Items to be Discussed at First Meeting
-
5STEMS ProjectSTEMS CONSULTANTS (PTE) LTD159, Model Farm Road, Colombo 08. Building
CONCRETING APPROVAL FORM - ADate: 18/08/2007 Time: am / pm Venue : Site
1 Location
2 Station From: Axis: Grid: To: Axis: Grid:
3 Level From: To:
4 Preparation of screed / Concrete surface:
5 Form work:
a) Quality :
b) Rigidity :
c) Verticality :
6 Reinforcement:
a) Number :
b) Size :
c) Pitch :
d) Spacer blocks :
e) Cleaning :
7 Concrete Vibrators in working order available at siNo: Size:
8 Concrete cube moulds available at site: No:
9 Approved for concreting Signature
Name
Organisation STEMS CONSULTANTS (PTE) LTD
10 Not approved for concreting Reasons
Signature
Name
Organisation STEMS CONSULTANTS (PTE) LTD
11 Date of concreting Date:
Concrete test cubes cast No:
12 Cube Test Results
PROPOSED 35 STOREY TOWER, LOT A1 & B3, GALLE ROAD, COLOMBO 03.
APARTMENT BUILDING
7 day 28 day
a. Concreting Approval Form A
STEMS ProjectSTEMS CONSULTANTS (PTE) LTD159, Model Farm Road, Colom bo 08. Building
CONCRETING APPROVAL FORM - BDate: 18/08/2007 Time: am / pm Venue : Site
1 Location
2 Station From: Axis: Grid: To: Axis: Grid:
3 Level From: To:
4 Electrical Works
a) Electrical conduits & inserts:
b) Earthing provisions:
5 Approved Signature
Name
Organisation
6 Water Supply, Waste Water, Sewerage & Fire Protection works
a) Water Supply Pipe Layout/ducts: Pipe dia:
b) Waste Water Pipe Layout/drains: Pipe dia:
c) Sewerage Pipe Layout/ducts: Pipe dia:
d) Fire Protection Pipe Layout/ducts: Pipe dia:
7 Approved Signature
Name
Organisation Building Services Consultants
Signature
Singapore Piling
Name of Resident Agent
PROPOSED 35 STOREY TOWER, LOT A1 & B3, GALLE ROAD, COLOMBO 03
APARTMENT BUILDINGb. Concreting Approval Form B
-
6No. QA - 1 ACTIVITY
2 DATE
3 STATUS OF ACTIVITY
4 ONGOING WORK:
5 REF DRAWINGS:
6 REF. SPECIFICATION
7 COMMENTS
8 QUALITY ASSURANCE PROCEDURES Implemented Yes / No
9 ITEMS TO BE INSPECTED
10 INSPECTION REQUIRED Date Time
11
Construction Engineer / KSJ Site Manager /KSJ
12
Reviewed . Resident Engineer, Vallibel Lanka Ltd
QUALITY ASSURANCE REPORT
COLOMBO 1.
PROPOSED ENTERTAINMENT COMPLEX AT COLOMBO 3.
VALLIBEL LANKA LTD27-02, EAST TOWER
WORLD TRADE CENTREECHELON SQUARE
STEMS STEMS CONSULTANTS (PTE) LTD159, Model Farm Road, Colombo 08
Issued to: .. Copies to: UDA / CCS / T&SW
Prepared by: . Checked by : Approved by :..Mr S A Karunaratne Mr Gamini Jayasinghe Mr Nihal FernandoStems Consultants (Pte) Ltd Engineer's Representative Engineer
Date : . Date : . Date : ..
Madiwela Government Project
Security Building
SITE INSTRUCTION / VARIATION ORDER NO. S/
Item Action by Description of Work
Project
Building
Request for Inspection a. Format for Site Instructions
b. Make notes on drawing about site instruction
STEMS Time Sheet No 27STEMS CONSULTANTS (PTE) LTD159, Model Farm Road, Colombo 08
Name S A KarunaratneWeek Ending 2001- 07 - Position Team LeaderDay
Date 1 2 3 4 5 6 01 02 03 04 05 06 07 08 09 10 11 12 13 14 N O T
MON
2TUE
3WED
4THU
5FRI
6SAT
7SUN
8
Stage: 1. Sur/Invest 2. F Study 3. Design 4. Tender 5. Construction 6. Follow up
Job Description: 01. Adm / P Mtg / Mtd 02. Data / Job Planning / Briefing 03. Estimate / Cost 04. Designs 05. Draughting06. Specifications 07. BOQ's 08. Checking 09. Amendments 10. Printing & Binding11. Correspondence 12. Site Inv / M Testing / Testing 13. Site Inspection 14. Supervision
8Total HoursHOURS Stage Job Description
Building:
Project:
Residence & Security Staff Buildings
Madiwela Government Project
Time Sheet
-
7240 piles
MADIWELA GOVERNMENT PROJECT PROGRAMME OF WORKS FOR THE SECURITY STAFF COMPLEX
New
Yea
r H
olid
ays
Tender Document Approval by TEC
Tender Document Approval by TEC
Tender & Award For Building Works
Test Pile Installation & ReportPile Drawings & Tender Documents
Piling Tender & Award
Pile Installation
Building Design & Drawings
May2001
JuneJanuary February March April2000ITEMS OF WORK
Preparation of Tender Documents
November December
Programme of Works Up-to Building Tender
B. Construction tolerances
-
8Construction tolerances Misalignment of
Face of Building in planFace of Building in plan 5mm in 3000mm & max. 25mm5mm in 3000mm & max. 25mmNothing over boundary line Nothing over boundary line
Footings & Pile CapsFootings & Pile Capsa) a) wrtwrt C L of wall or columnC L of wall or columnb) Dimension in planb) Dimension in planc) Thicknessc) Thickness
2% of footing width; max. 50mm2% of footing width; max. 50mm+ 50mm ; + 50mm ; -- 10mm10mm+ 10% ; + 10% ; -- 5% ; max. + 10mm5% ; max. + 10mm
VerticalVerticala) Lines & surfaces of wall, a) Lines & surfaces of wall, columcolumb) Column & wall from plumbb) Column & wall from plumb
5mm in 5000mm & max. 12mm5mm in 5000mm & max. 12mm12mm in 30m: 20mm in 60m &12mm in 30m: 20mm in 60m &25mm up to 90m and above25mm up to 90m and above
Max. deviation of mean levelMax. deviation of mean levela)a) 3m height from lower floor 3m height from lower floor b)b) 6m height from lower floor6m height from lower floorc)c) 12m height from lower floor12m height from lower floord)d) In any upper floorIn any upper floor
6mm6mm12mm12mm20mm20mm20mm 20mm ctdctd --
Levels & GradientLevels & Gradienta) In 3m length of floor & beam soffita) In 3m length of floor & beam soffitb) In 6m length of floor & beam soffitb) In 6m length of floor & beam soffitc) For the whole lengthc) For the whole length
6mm6mm10mm10mm20mm20mm
Lintels, sills, parapets & groovesLintels, sills, parapets & groovesa) In a 6m lengtha) In a 6m lengthb) In 12m or moreb) In 12m or more
6mm horizontally6mm horizontally10mm horizontally10mm horizontally
Cross SectionsCross Sectionsa) Dimensiona) Dimension < 150mm< 150mmb) Dimension 150mm & > 150mmb) Dimension 150mm & > 150mm
+10mm ; +10mm ; --3mm3mm+12mm; +12mm; --6mm6mm
OpeningsOpeningsa) Sizes and locationsa) Sizes and locationsb) Additional margins for windows, doors b) Additional margins for windows, doors
or lift door installations Contractors or lift door installations Contractors responsibilityresponsibility
+6mm ; +6mm ; --6mm6mm
StairsStairsa) Deviation in risersa) Deviation in risers
b) Deviation in treadsb) Deviation in treads
In consecutive step + 2mmIn consecutive step + 2mmIn any flight, + 6mmIn any flight, + 6mmIn consecutive step + 3mmIn consecutive step + 3mmIn any flight, + 6mmIn any flight, + 6mm
-
9Removal of formwork & props minimum periods recommended
Beam sides, walls & columns (unloaded)Beam sides, walls & columns (unloaded) 24 hours24 hours
Slab (props left in place)Slab (props left in place) 4 days4 days
Beam Beam soffitssoffits (props left in place)(props left in place) 7 days7 days
Props to slabs between beamsProps to slabs between beams 14 days14 days
Props to beams & flat slabsProps to beams & flat slabs 14 days14 days
Props to cantileversProps to cantilevers 28 days28 days
C. Material Testing
-
10
Proctor Compaction Test
(a) Standard (S P C T)
(b) Modified (M P C T)
Soil TestsProctor
CBR
(a). 5.5 lb hammer; 12 drop; volume of 4 mould 944cm3
(b). 10 lb hammer; 18 drop; volume of 6 mould 2123cm3
-
11
(b) Proctor Compaction Apparatus for Heavy Compaction
(a) Proctor Compaction Apparatus for LightCompaction
(a)(b)
(a)
-
12
(1) Optimum Water Content 13.1%
(2) Maximum Dry Density 1.87 g/cm3
-
13
Moisture Content in percent for complete saturation = Wsat
Density of water in g/cm3 = wSpecific gravity of soil = Gs
Dry density of soil in g/cm3 = dWsat = (w/d 1/Gs) d = w/(w/100 + 1/Gs)
Moisture Content in percent = w
Wet density of soil in g/cm3 =
S P C T is generally used in small fills, parking lots and for building structures
M P C T is generally used in large fills, roads, Airport Runways and Concrete Parking Aprons and for building structures
Field compaction done with different type of rollers
(a) Clayey and Silty Soils use Sheepsfoot rollers
(b) Granular Soils use Smooth-drum or Vibratory rollers
%age of Optimum Compaction attained in the field is Relative Density or R (%)
1) R(%) for S P C T is 95% - 100%
2) R(%) for M P C T is 90% - 95%
3) R(%) for granular fills is 95% - 100%
Common R(%) field test is Sand Replacement Method
-
14
California Bearing Ratio (CBR) testing (Laboratory) apparatus
CBR
California Bearing Ratio (CBR) testing apparatus
-
15
California Bearing Ratio (CBR) testing apparatus in the field
CBR relationship of force & penetration of a cylindrical plunger of 3 inch2 at a standard rate into soil. 0.05 per minute
CBR in essence evaluate strength of subgrades
High CBR lower pavement thickness & vise versa
CBR valueCBR value SubgradeSubgrade strengthstrength
3% and less3% and less PoorPoor
3% 3% -- 5%5% NormalNormal
5% 5% -- 15%15% GoodGood
Other field apparatus used to determine CBR
(a)Hand held Mexe Penetrometer indicate CBR values upto 3m depth
(b) Dynamic Cone Penetrometer
could be used to evaluate results using a formula
-
16
Stress Penetration Curves of CBR Tests
Reinforcement & Concrete
-
17
R/F bar tests to BS 4449a) Proof / Yield stress > Characteristic strength of 460 or 250 N/mm2
b) Tensile strength > Proof / Yield stress
c) %age elongation 12% for 460A & 14% for 460B
d) %age elongation 22% for MS - 250
e) Stress ratio (TS / YS) >= 1.05 for 460A & 1.08 for 460B
f) Stress ratio (TS / YS) >= 1.15 for MS
460A rib pattern 460B rib pattern
Bar Diameter ( Bar Diameter ( ) mm) mm66 88 1010 1212 1616 2020 2525 3232 4040
0.2220.222 0.3950.395 0.6160.616 0.8880.888 1.5791.579 2.4662.466 3.8543.854 6.3136.313 9.8649.864
99 6.56.5 6.56.5 4.54.5 4.54.5 4.54.5 4.64.6 4.54.5 4.54.5
0.2420.242 0.4210.421 0.6560.656 0.9280.928 1.6501.650 2.5772.577 4.0274.027 6.5976.597 10.30810.308
0.2020.202 0.3690.369 0.5760.576 0.8480.848 1.5081.508 2.3552.355 3.6813.681 6.0286.028 9.4209.420
Reinforcement weight - kg / m
3rd row :- Average weight
4th row :- + Tolerance
5th row :- Upper limit kg/m6th row :- Lower limit kg/m
-
18
Chemical analysis and Carbon equivalenceElementElement Grade 250Grade 250 Grade 460Grade 460
% Max% Max % Max% Max
CarbonCarbon 0.250.25 0.250.25
SulphurSulphur 0.0600.060 0.0500.050
PhosphorusPhosphorus 0.0600.060 0.0500.050
NitrogenNitrogen 0.0120.012 0.0120.012
Max. Carbon equivalent Max. Carbon equivalent values (CEV)values (CEV)
0.420.42 0.510.51
CEV = C + Mn/6 + (Cr + Mo + V)/5 + (Ni +Cu)/15
STEMS STEMS CONSULTANTS (PTE) LTD Computed By: S A Karunaratne159, Model Farm Road, Colombo 08 Date: 2006-11-24
Analysis of 36 No. cube test results furnished by SUPERMIX to Singapore Piling
for Grade 35 concrete to be used for concreting in Luxary Apartment Building at Lot A1 & B3, Galle Road, Colombo 03.
(Analysis carried out in place of trial batching to verify the "Mix Design")Result
No Date Cast Date Tested Age Days N/mm2
at test fi fi - fm (fi - fm)2
1 1-9-06 29-9-06 28 34.5 -6.60 43.522 1-9-06 29-9-06 28 40 -1.10 1.203 1-9-06 29-9-06 28 41 -0.10 0.014 31-8-06 28-9-06 28 47.5 6.40 41.005 31-8-06 28-9-06 28 42 0.90 0.826 31-8-06 28-9-06 28 41.5 0.40 0.167 30-8-06 27-9-06 28 35.5 -5.60 31.338 30-8-06 27-9-06 28 39 -2.10 4.409 30-8-06 27-9-06 28 37.5 -3.60 12.9410 14-8-06 11-9-06 28 36.5 -4.60 21.1311 14-8-06 11-9-06 28 38 -3.10 9.5912 14-8-06 11-9-06 28 39 -2.10 4.4013 13-8-06 10-9-06 28 43 1.90 3.6214 13-8-06 10-9-06 28 42.5 1.40 1.9715 13-8-06 10-9-06 28 40 -1.10 1.2016 8-8-06 5-9-06 28 37.5 -3.60 12.9417 8-8-06 5-9-06 28 39.5 -1.60 2.5518 8-8-06 5-9-06 28 35.5 -5.60 31.3319 30-7-06 28-8-06 29 47 5.90 34.8420 30-7-06 28-8-06 29 41.5 0.40 0.1621 30-7-06 28-8-06 29 46 4.90 24.0422 27-7-06 24-8-06 28 43 1.90 3.6223 27-7-06 24-8-06 28 44 2.90 8.4324 27-7-06 24-8-06 28 43.5 2.40 5.7725 23-7-06 21-8-06 29 41.5 0.40 0.1626 23-7-06 21-8-06 29 46 4.90 24.0427 23-7-06 21-8-06 29 41.5 0.40 0.1628 22-7-06 21-8-06 30 41.5 0.40 0.1629 22-7-06 21-8-06 30 41.5 0.40 0.1630 22-7-06 21-8-06 30 42 0.90 0.8231 30-6-06 28-7-06 28 44 2.90 8.4332 30-6-06 28-7-06 28 35.5 -5.60 31.3333 30-6-06 28-7-06 28 45 3.90 15.2334 29-6-06 23-8-06 55 39.5 -1.60 2.5535 29-6-06 23-8-06 55 41 -0.10 0.0136 29-6-06 23-8-06 55 45.5 4.40 19.3837 0.00 0.0038 0.00 0.0039 0.00 0.0040 0.00 0.00
36Total = 1479.5 403.41
Average = Total /36 fm = 41.10s = (fi - fm2/ 36 3.35
1.64 s = 5.49Therefore fcu = fm - 1.64s = 35.61 N/mm2 > 35N/mm2
Note: Concrete Cube results are acceptableHowever, No. of cube results less than 40 and Contractor is responsible
Analysis of recently cast concrete test cube results in place of mix design trial mix tests
-
19
A6 B6
C6D6
AB BABC
CBCDDCDAAD
150 Cast Cube mould markings
Casting concrete cylinders & cubes for tests(i) Place concrete in three layers
(ii) Compact each layer 35 blows; 350mm long
16mm rod or 25mm2 area bar (600mm bullet nosed rod)
150 x 300 CAST MOULD
STEMS Project 35 Storey Tower, Lot A1 & B3, Colombo 03STEMS CONSULTANTS (PTE) LTD Computed By: S A Karunaratne159, Model Farm Road, Colombo 08 Date: 2007-08-18
Compressive Strength (28 Day Test Results) - To BS 5328: Part 4: 1990: Clause 3.16.2
Set Of Results No CC/02/239Specified Compressive Strength = 30 N/mm^2Number of Cube Results available= 3
Test Cube Result 1 = 45.5 N/mm^2 Condition (b) Satisfied 45.5 > 27 N/mm^2Test Cube Result 2 = 48 N/mm^2 Condition (b) Satisfied 48 > 27 N/mm^2Test Cube Result 3 = 50 N/mm^2 Condition (b) Satisfied 50 > 27 N/mm^2Test Cube Result 4 = 0 N/mm^2 Not Applicable
Average Results = 47.83 N/mm^2 Condition (a) Satisfied 47.83>=32 N/mm^2
Therefore Concrete Cube Results is OKAY
Set Of Results No CC/02/251Specified Compressive Strength = 30 N/mm^2Number of Cube Results available= 2
Test Cube Result 1 = 34.5 N/mm^2 Condition (b) Satisfied 34.5 > 27 N/mm^2Test Cube Result 2 = 29.5 N/mm^2 Condition (b) Satisfied 29.5 > 27 N/mm^2Test Cube Result 3 = 0 N/mm^2 Not ApplicableTest Cube Result 4 = 0 N/mm^2 Not Applicable
Average Results = 32 N/mm^2 Condition (a) Satisfied 32>=31 N/mm^2
Therefore Concrete Cube Results is OKAY
Set Of Results No CC/02/223Specified Compressive Strength = 30 N/mm^2Number of Cube Results available= 3
Test Cube Result 1 = 49.5 N/mm^2 Condition (b) Satisfied 49.5 > 27 N/mm^2Test Cube Result 2 = 47.5 N/mm^2 Condition (b) Satisfied 47.5 > 27 N/mm^2Test Cube Result 3 = 46.5 N/mm^2 Condition (b) Satisfied 46.5 > 27 N/mm^2Test Cube Result 4 = 0 N/mm^2 Not Applicable
Average Results = 47.83 N/mm^2 Condition (a) Satisfied 47.83>=32 N/mm^2
Therefore Concrete Cube Results is OKAY
Set Of Results No 0Specified Compressive Strength = 30 N/mm^2Number of Cube Results available= 4
Test Cube Result 1 = 30 N/mm^2 Condition (b) Satisfied 30 > 27 N/mm^2Test Cube Result 2 = 50 N/mm^2 Condition (b) Satisfied 50 > 27 N/mm^2Test Cube Result 3 = 34 N/mm^2 Condition (b) Satisfied 34 > 27 N/mm^2Test Cube Result 4 = 29 N/mm^2 Condition (b) Satisfied 29 > 27 N/mm^2
Average Results = 35.75 N/mm^2 Condition (a) Satisfied 35.75>=33 N/mm^2
a. Concrete test cube compliance
-
20
D. Concrete
Type of concreteType of concrete Max. total % Max. total % of chloride ion of chloride ion by mass of by mass of combined combined aggregateaggregate
Max. total % of Max. total % of chloride ion by chloride ion by mass of mass of cementcement
PrestressedPrestressedconcreteconcreteR/C with cement to R/C with cement to BS 12BS 12R/C with cement to R/C with cement to BS 4027 & BS 4248BS 4027 & BS 4248
0.100.100.010.01
0.050.05 0.400.40
0.030.03 0.200.20
Chloride in fine aggregate & in concrete
-
21
Maximum shell content in offshore sand
SizeSizeLimit on shell Limit on shell content (%)content (%)
Fractions of single size or of graded or Fractions of single size or of graded or allall--in aggregate, coarser than 10mmin aggregate, coarser than 10mm 88
Fractions of 10mm single size, or of Fractions of 10mm single size, or of graded or allgraded or all--in aggregate finer than in aggregate finer than 10mm & coarser than 5mm10mm & coarser than 5mm
2020
Aggregate finer than 5mmAggregate finer than 5mm No No requirementrequirement
GRADES GRADES C C
AveraAvera 4 4 ResultsResults
AveraAvera 3 3 ResultsResults
AveraAvera 2 2 ResultsResults
BS & {ICTAD} BS & {ICTAD} IndiviIndivi. Result > . Result >
C8/10C8/10 12(2)12(2) 11(1)11(1) 10(0)10(0) 8(2) ; {8(2)}8(2) ; {8(2)}
C12/15C12/15 17(2)17(2) 16(1)16(1) 15(0)15(0) 13(2) ; {13(2)}13(2) ; {13(2)}
C16/20C16/20 23(3)23(3) 22(2)22(2) 21(1)21(1) 17(3) ; 17(3) ; {18(2)}{18(2)}
C20/25C20/25 28(3)28(3) 27(2)27(2) 26(1)26(1) 22(3) ; 22(3) ; {23(2)}{23(2)}
C25/30C25/30 33(3)33(3) 32(2)32(2) 31(1)31(1) 27(3)27(3)
C28/35C28/35 38(3)38(3) 37(2)37(2) 36(1)36(1) 32(3)32(3)
C32/40C32/40 43(3)43(3) 42(2)42(2) 41(1)41(1) 37(3)37(3)
C40/50C40/50 53(3)53(3) 52(2)52(2) 51(1)51(1) 47(3)47(3)
Compliance criteria of concrete cube test results
Cast 6 cubes; Test 01 at 07 days (0.75 of 28 days strength) ; Test 04 at 28 days
(b) Lowest individual strength of any cube > 0.85 of characteristic strength
The difference of strength of two specimens < 15% of mean strength
(a) Average of 3 cubes >=characteristic strength
Two test specimens form a single result for compliance with the above chart
(Max Mini) of 3 results < 20% of average of 3 results
For small projects -ICTAD
-
22
What is C35A concrete
Grade 35 concrete for structures retaining Aqueous (Water like) - (suffix - A) liquids
Maximum cement content 400 kg/m3
Minimum cement content 325 kg/m3
Maximum free water cement ratio 0.55(Water reducing agents could be used)
Aggregates Maximum water absorption
-
23
READY MIXED CONCRETECentral MixedCentral Mixed Transit MixedTransit MixedAggregate added at speed Aggregate added at speed 10 to 18 rpm up to 100 10 to 18 rpm up to 100 revolutionsrevolutions
Materials are batched in a Materials are batched in a central plant central plant no addition no addition of waterof water
Transport Agitator Truck 2 Transport Agitator Truck 2 to 6 rpmto 6 rpm
Mixing in transit or at Mixing in transit or at discharge speed 4 to 16 discharge speed 4 to 16 rpm of truck mixerrpm of truck mixer
For uniformity of mixing For uniformity of mixing limit to 300 revolutionslimit to 300 revolutions
For uniformity of mixing For uniformity of mixing limit to 300 revolutionslimit to 300 revolutionsCement balls up to 200mm Cement balls up to 200mm if no proper controlsif no proper controls
The speed of mixing affects the rate of stiffeningThe speed of mixing affects the rate of stiffening
Basic Requirements for Basic Requirements for Placing Concrete (1)Placing Concrete (1)
Preserve concrete qualityPreserve concrete quality WaterWater--cement ratiocement ratio SlumpSlump HomogeneityHomogeneity
Avoid separation of aggregate and Avoid separation of aggregate and mortarmortar
-
24
Basic Requirements for Basic Requirements for Placing Concrete (2)Placing Concrete (2)
Avoid excessive horizontal movementAvoid excessive horizontal movementConsolidate adequatelyConsolidate adequatelyMaintain sufficient placement capacityMaintain sufficient placement capacityChoose the right equipment for the concreteChoose the right equipment for the concrete
Depositing ConcreteDepositing Concrete
Start placing along perimeter at one end Start placing along perimeter at one end with each batch discharged against with each batch discharged against previously placed concretepreviously placed concrete
Do not Do not (a) dump in separate piles & then (a) dump in separate piles & then
level and work togetherlevel and work together(b)(b) deposit in large piles & then deposit in large piles & then move move horizontally into positionhorizontally into position
These practices result in segregationThese practices result in segregation(mortar flows ahead of coarser material)(mortar flows ahead of coarser material)
Slab Construction
-
25
Incorrect Placement with Incorrect Placement with Conveyor BeltConveyor Belt
Baffle
MortarRock
Mortar
MortarRock
Shallow hopper
Placement with Placement with Conveyor BeltConveyor Belt
Belt Scraper
No Separation
Provide at least 0.6 m (24 in.) headroom for downpipe, elephant trunk or equivalent
-
26
Depositing ConcreteDepositing Concrete Deposit in horizontal layers of Deposit in horizontal layers of
uniform thicknessuniform thickness Reinforced Reinforced 150 mm to 500 mm150 mm to 500 mm Mass Mass 375 mm to 500 mm375 mm to 500 mm
Consolidate each layer before Consolidate each layer before next is placednext is placed
Timely placement & Timely placement & consolidation prevents flow linesconsolidation prevents flow linesand cold jointsand cold joints
Walls
Placing Concrete Placing Concrete in pilesin piles
Used: Tremie
Advantages: Can be used to funnel concrete down through the water / bentonite into the structure.
Watch for: Discharge end always has to be buried in fresh concrete to ensure seal between water and concrete mass.
-
27
Consolidating Consolidating ConcreteConcrete
Internal VibrationInternal Vibration
External VibrationExternal Vibration
Internal VibrationInternal Vibration
d
R
1 R
Vibrator
Radius of Action
-
28
Internal VibratorsInternal Vibrators of of head,head,mmmm
frequency, frequency, vibrations vibrations per minuteper minute
radius of radius of action, action,
mmmm
Rate of Rate of placemenplacemen
t,mt,m33/h/h ApplicationApplication
2020--4040 90009000--15,00015,000 8080--150150 0.80.8--44
3030--6060 85008500--12,50012,500 130130--250250 2.32.3--88
5050--909080008000--12,00012,000
180180--360360 4.64.6--1515 Stiff plastic Stiff plastic concrete (less than concrete (less than
8080--mm slump) mm slump)
Plastic concrete in Plastic concrete in thin walls, thin walls,
columns, beams, columns, beams, precast piles, thin precast piles, thin
slabs, slabs,
Plastic and flowing Plastic and flowing concrete in thin concrete in thin members. Also members. Also
used for lab test used for lab test specimens.specimens.
Systematic Vibration of Systematic Vibration of Each New LiftEach New LiftCORRECTCORRECTVertical penetration a few inches into previous lift (which should not yet be rigid) of systematic regular intervals will give adequate consolidation
INCORRECTINCORRECTHaphazard random penetration of the vibrator at all angles and spacingswithout sufficient depth will not assure intimate combination of the two layers
-
29
Placing Concrete in a Placing Concrete in a Sloping LiftSloping Lift
CORRECTCORRECTStart placing at bottom of slope so that compaction is increased by weight of newly added concrete. Vibration consolidates the concrete.
INCORRECTINCORRECTWhen placing is begun at top of slope the upper concrete tends to pull apart especially when vibrated below as this starts flow and removes from concrete above.
External VibrationExternal Vibration
Form vibratorsForm vibratorsVibrating tablesVibrating tablesSurface vibratorsSurface vibrators Vibratory hand floats or trowelsVibratory hand floats or trowels
-
30
Floating (Power or Hand)Floating (Power or Hand) To embed aggregate To embed aggregate
particles just beneath the particles just beneath the surface surface
To remove slight To remove slight imperfections, humps, and imperfections, humps, and voidsvoids
To compact the mortar at To compact the mortar at the surface in preparation the surface in preparation for additional finishing for additional finishing operations. operations.
TrowelingTroweling Creates smooth, Creates smooth,
hard,dense surfacehard,dense surface Exterior concrete should Exterior concrete should
not be not be troweledtroweled because: because: it can lead to a loss of it can lead to a loss of
entrained air caused by entrained air caused by overworking the surfaceoverworking the surface troweledtroweled surfaces can be surfaces can be
slippery when wet. slippery when wet.
-
31
Curing and ProtectionCuring and Protection
Cure for 7 daysCure for 7 days
Impervious CoverSprinkling of water
Curing Agent
Minimum period for curing Minimum period for curing & protection& protectionSurface concrete Surface concrete temperature temperature oo CC5 5 -- 1010 > 10> 10 2525
AverageAverage 4 Days 4 Days 3 Days 3 Days 2 Days 2 Days
PoorPoorAverageAverage
66 44 33All except All except (1) with (1) with ggbfsggbfs or or pfapfa
PoorPoor 1010 77 44
AllAll GoodGood No curingNo curing
(1) OPC, (1) OPC, RHPC, RHPC, SRPCSRPC
Type of Type of cementcement
Ambient Ambient conditions conditions after after concretingconcreting
Table 6.5 of BS 8110
-
32
Controlling temperatures in mass concrete
Volume > 300m3 & thickness > 600mm
i. Concrete temperature to 600 C maximum
ii. Temperature difference at center & surface to 200 C maximum
Limit
a. Temp > 710 C - internal expansion & cracking
b. Temp > 880 C - reduced compressive strength
Or minimum dimension > 1.8m
50kg cement temperature increase very approx. 4.290 C 7.140 C ; control with fly ash / ggbfs
Temperature rise in concrete above ambient Temperature rise in concrete above ambient surrounding surrounding in in 00 CC
Section Section thickness thickness (mm)(mm)
18mm plywood 18mm plywood (Steel)(Steel) formwork formwork cement content cement content -- kg/mkg/m3 3
220 290 360 400220 290 360 400
10 10 --1414 14 14 -- 1919 18 18 -- 2626 21 21 -- 3131
5 5 -- 77 7 7 -- 1010 9 9 -- 1313 10 10 -- 1515
9 9 -- 1313 13 13 -- 1717 16 16 -- 2323 19 19 -- 2727
13 13 -- 1717 18 18 -- 2424 23 23 -- 3333 27 27 -- 3939
18 18 -- 2323 24 24 -- 3232 33 33 -- 4343 39 39 -- 4949
15 15 -- 1919 20 20 -- 2727 27 27 -- 3636 31 31 -- 4343
18 18 -- 2323 25 25 -- 3232 34 34 -- 4343 40 40 -- 4949
22 22 -- 2727 31 31 -- 3737 42 42 -- 4848 47 47 -- 5656> 1000> 1000
700700
500500
< 300< 300
-
33
150mm sand layer or felt
25mm polystyrene or
Shear R/F
Main R/F
polythene layer
Additional R/F mesh
Formwork
First concrete pour
Balance concrete to be poured
Surface Insulation Arrangement (warm the surface & reduce temp difference
Working Safely with ConcreteWorking Safely with ConcreteProtect:Protect:
Your EyesYour Eyes
Your BackYour Back
Your SkinYour Skin
-
34
E. Detailing
COVER & SPACERS FOR REINFORCED CONCRETE
-
35
Cover to R/FoCover to R C Member is the minimum thickness of concrete over the R/F steelmeasured from exposed surface to the closest reinforced steel surface.
oCover is subjected to ingress of moisturealong with other chemicals, impact & wear
oCover should be dense having low permeability, durable, strong, free from honeycombs, cracks, voids & should be wear resistant
Cover to R/Fo Cover protects R/F steel from corrosion
o Cover ensures R/F bond to concrete to developits strength
o Spacers ensure location of R/F at the right location
o Incorrect R/F placement can lead even to failureso For eg. lowering top R/f or raising bottom R/F by 12mm in a 150mm slab, load carrying capacity could reduce by 20%
-
36
LocationLocation Minimum coverMinimum cover
Concrete in contact Concrete in contact with groundwith ground
75mm75mm
-- Do with formworkDo with formwork 50mm50mmColumnsColumns Main Main 40mm, links 40mm, links 25mm25mmWallsWalls 25mm & > 25mm & > of barof barBeamsBeams 35mm & > 35mm & > of bar, Links of bar, Links --
20mm20mmSlabsSlabs 20mm20mmEnd of barsEnd of bars 25mm & > 2 25mm & > 2 of barof barAt the foot of chairsAt the foot of chairs > Cover to main bars of member> Cover to main bars of member
Minimum cover to reinforcement
Extensively corroded slab and beam
-
37
Devices used to provide coveroStone chips get dislodged, & undesirable
oWood spacers inexpensive, difficult toremove & undesirable
o Cement mortar cover blocks inexpensive,porous, full of voids and allow moisturepenetration & undesirable
o Concrete cover blocks, Plastic spacers & Metal spacers costly, produced withquality & desirable
SPACERS
SPACERSSpacers are components which providecover (between 15 to 100mmin increments of 5mm,) between reinforcement and formwork or blinding.
Two main groups of spacers are: Clip-on typeWire-on type attach to bar by tying wire
-
38
Cementitious spacers
The mix used for spacer blocks should becomparable in strength , durability, porosity and appearance to the surrounding concrete.
Concrete spacers made at site must not be used according to BS 8110. How practical in Sri Lanka?
Making 75mm concrete cover blocks
-
39
t = nominal cover
t
Concrete cover blocksSeat min. =St2 + 75mm
Upstand height =h - ct - cb - t1 - t2 - b1 - b2
Leg length min.Sb2 + 75mm
Re - bar chair
Shape of traditional spacers
Concrete cover blocks and re-bar chairs
-
40
PLASTIC CHAIRS
-
41
Tying wire
16 gauge black annealed wire. Corrosion resistant wire of equal strengthmay be used.
Projecting ends of tying wire should not encroach into concrete cover.
No need to tie at every intersection
SLABS
Perimeter bars tied at every intersection
Bars up to 20mm tie at alternate intersections
Greater centres for R/F 25mm & above but notexceeding 50 of the smallest bar.
TYING OF BARS
SPACERS FOR SLABS continued
-
42
Section Section
Key Plan view of spacer Side view of spacer nominal size of bar
nearest to surface
500mm max
50 , but
-
43
Spacers on alternate bars
Section Elevation
a) Without horizontal R/F
Spacers at 50 or at a maximumof 1000mm centres
Section Elevation
b) With horizontal R/FKey Plan & side view of spacer
Wire tie
Spacers for slab edges
Spacers in a slab
-
44
BEAMS
TYING WITHIN BEAMS Every intersection of a corner of a link
with longitudinal bar should be tied.
Other bars within the links should be tied at 50D centres
SPACERS FOR BEAMS continued
Every bar endshould have asuitable spacer
1000mm max. Up to 250mm, one spacer
Beam elevation Narrow beam
Deep beam> 100
Spacers @ Spacers @ 50 max. 50
250 to 500mm Wide beam > 500mm two spacers
Spacers for sides of deep beams
Normal Deep beam Wide beambeam
Spacers for beams
-
45
Spacers in a deep beam
COLUMNSTYING WITHIN COLUMNS
Main vertical bars and links should betied at every intersection
Spacers for spiral links follow same rulesas for circular columns
SPACERS FOR COLUMNS continued
-
46
Spacers @50 maximum
All spacers fixed to links at top, middle Face
& bottom of each lift, < 50 not exceeding 100
Face > 50
Spacers along column Wide columnFaces less Spacers @ 50 maximumthan 50 At least four per group
One spacer per 50 ofbar for
each facet
Small column Multifaceted columns Circular column
Spacers for columns
WALLSTYING WITHIN WALLS
Follow guidelines given for slabs
Spacers on opposite faces should coincidewhen viewed in elevation
SPACERS FOR WALLS continued
-
47
Continuous chairs at a maximum of 1000mm centres
50 or 500mm
Spacers at a max. of 50 but not less than 500mm in both directions
Elevation SectionKey Plan & end view of spacer
Plan view of continuous chairSide view of continuous chair
End view of continuous chair
Plan Spacers for walls
Spacers in wall R/F
-
48
Earthquake effects mitigation detailing
- Dia. Of cross tie
Shape of stirrups & crossties
135 o
90 o 135 o
Stirrup or hoop Crosstie
Values given in ( ) are for mild steel reinforcement)
beam confinement zones and wall end zones
Stirrups & crossties for columns, beam-column joints
135 o
>=6 (10)>=80mm (100mm)
Dia >=5hoop
-
49
Actual shape of stirrup
Reinforcement in a wall
Wheel Spacer
Cross Tie
-
50
1350 hook
Column Vertical R/F arrangement
0.5l
ln/2
ln/2
for R/F lap
Structurallyln
for R/F lap
(a)
(b) = 3/4 of adjoining column width;is defined as confined joint
(a) > 50% R/F lapped
1.25l
-
51
Column Transverse R/F arrangement
X
At least 60% of transverse R/F provided in the
zone belowprovided in confinement
confinement zone below to be provided
Sc=50mm; =ln/6; >=500mm
o1 o2 o1
Link arrangement
at laps in columns
d = 2
b = 10
Double links at bends
Links at laps as in the
confinement zones
Crank detail
Column link arrangement at laps
-
52
FAILURE OF
COLUMNS
Beam longitudinal R/F arrangement
Wall
l
>= l>= 50
>= l >= l
ln
1/4 of max. support R/F
a
abb
(a+b)>=la>= 0.4 lb>=12
Bottom R/F of adjacentspan
Note: Do not provide bent-up bars
-
53
Beam Transverse R/F arrangement
combination ofstaggared with
closed links
Beam withclosed links
Side bars Crosstiesalternatively
= 2hk