Method Statement for In-situ Concrete & General Concrete Work

This method statement for in-situ concrete & general concrete work describes the process to be implemented during the entire activity for such as in-situ concrete, concrete foundations, slab on grade, blindings,  columns, beams, retaining walls, slabs, raft concrete, precast concrete, self-consolidating concrete, mass concrete and any structural concrete works. The adopted codes govern on this method statement for concrete is the British Standard (BS) but it should be based in order of precedent with the Project Specifications, Contract Agreement, Addendum and Special Provisions, etc.

This method is not fully comprehensive but helpfully provides the ideas on how the concrete works associated with the risk assessments and related requirements are outlaid.

Same with the method statement for block works/masonry, this presentation can be formatted to help the Technical Department/Construction Department/QA Department prepares the required method statement for concrete works which is being submitted to Consultant for review and approval as part of project’s QA documentation.

mixer
Ongoing ready-mixed concrete pouring

Method Statement for In-situ Concrete & General Concrete Work

I. Description of Works
1. Introduction
2. Definitions
3. Reference
4. Responsibilities
5. Interfacing with Other Operations
6. Duration, Phasing with the Subcontractors
7. List of Subcontractors
II. Resources
1. Plant and Equipment
2. Work Force
3. Light Tools
III. Materials
1. Ready-mixed concrete
2. Steel Reinforcement
3. Plastic Spacers
4. Concrete Spacers
5. Tie Wires 1.6 mm
6. Curing Compound
7. Formwork Release Agent
8. Waterstops
9. Waterproofing Materials
10. Dampproofing Materials
11. Bonding Agent
12. Sealant
13. Epoxy
14. Formworks
15. Gauge 1000 approved Polyethylene Sheet
16. Concrete Repair Materials
IV. Site Planning
1. Preparation
2. Site Clearance
3. Traffic Management
4. Pre-construction Safety Meetings
5. Operating Procedures
V. Methodology
V.1 General
V.2 Reinforcement
V.2.1 Material Handling and Reception
V.2.2 Mechanical Splices
V.2.3 Sampling and Testing
V.2.4 Reinforcement Fabrication and Placement
V.3 Formwork
V.3.1 General Criteria
V.3.2 Material and Class of Finish
V.3.3 Formwork Execution
V.3.4 Formwork Removal
V.3.5 Dimensional Tolerances
V.3.6 Early Loading
V.4 Concrete Transport
V.5 Concrete Casting
V.5.1 Preparation for Pour
V.5.2 Placing of Concrete
V.5.2.1 General
V.5.2.2 Foundation Concreting
V.5.2.2.1 General
V.5.2.2.2 Procedure of Work
V.5.2.3 Concreting of Retaining Wall and Vertical Structures
V.5.2.4 Mass Concreting
V.5.2.5 Roof Slab
V.5.3 Joints in the Concrete:
V.5.3.1 General
V.5.3.2 Construction Joint
V.5.3.3 Movement Joints
V.5.3.4 Construction of Joints
V.5.3.4.1 Forming Joints
V.5.3.4.2 Forming Grooves
V.5.3.4.3 Protection of Grooves
V.5.3.4.4 Sealing Joints
V.5.3.4.5 Tolerances
V.6 Compaction
V.7 Curing
V.8 Hot Weather Concreting
V.8.1 General
V.8.2 Potential Problems Associated with Concreting in Hot Weather
V.8.2.1 Plastic Concrete
V.8.2.2 Hardened Concrete
V.8.2.3 Avoiding Potential Problems
V.8.3 Concrete Placing and Curing
V.8.4 Controlling Reducing Temperature of Constituent Materials
V.8.4.1 Aggregates
V.8.4.2 Water
V.8.4.3 Cement
V.8.5 Reducing Heat Gain
V.9 Precast Concrete Works
V.9.1 General
V.9.2 Testing
V.9.3 Delivery, Storage & Handling
V.9.4 Forming
V.9.5 Erection
V.10 Sampling and Testing
V.10.1 Slump Test
V.10.2 Concrete Strength Test Sampling
V.10.3 Testing of Concrete Cube Samples
V.11 Concrete Repair
V.11.1 General
V.11.2 Identification of Defects
V.11.2.1 Crazing
V.11.2.2 Blowholes (re-profiling 0 to 10 mm deep)
V.11.2.3 Form Tie Rod / Bolt Holes and Voids
V.11.2.4 Honeycomb with rebar not exposed and () 50 mm deep
V.11.2.6 Concrete repair work in generally re-profiling over large area where
thickness are more than 3mm
V.11.2.7 Cold Joints
V.11.2.8 Dry / Damp cracks, early thermal contraction cracks, drying shrinkage
cracks on external wall and side part of base slab (equal or greater than 0.20mm)
V.11.2.9 Non- structural cracks, e.g. shrinkage cracks or surface cracks equal or
greater than (>) 0.20mm, but ( 0.2 mm), Deep-seated cracks (beyond rebar
zone) or through cracks larger than 0.2 mm
V.11.2.11 Wet Cracks
VI. Risk Assessment and Job Hazard Analysis
VII. Permit and Licensing Requirements
VIII. Drawings, Diagrams and Maps
IX. Pre-Start Safety Briefing Arrangements
1. Protective and Safety Equipment
2. Information to Personnel
3. Special Safety Requirements
4. Emergency Procedures
5. Emergency Contact Numbers
X. Supervision and Monitoring Arrangements
Construction Manager
Site Engineer
Site Foreman
QA/QC Engineer
HSE Engineer
Chief Surveyor
XI. Environment and Quality Issues
1. Precautionary Measure
2. Disposal Requirements
3. Inspection, Test and Sampling
4. Quality Assurance Requirements Table
XII. Attachments
1. Risk Assessment
2. Reference Documentation
3. List of Appendices
APPENDIX A: Drawings, Diagrams, and Maps
APPENDIX B: Risk Assessment
APPENDIX C: Permit & Licensing Requirements Permit to Work
APPENDIX D: Inspection & Testing Plan (ITP)
APPENDIX E: QC Formats
APPENDIX F: Material Safety Data Sheet & Test Certificates of Materials
APPENDIX G: Approved Material Submittals

I. Description of Works
1. Introduction
This method statement defines the sequence and describes the control procedures to be followed for concrete work of Project xxxxx (Name of Project goes here).
The purpose of this Method Statement is to establish the rules to be applied during all the concrete works (including in-situ concrete, precast concrete and concrete repair works) starting from storage of materials, reinforcement work, formwork, transportation of material, inspection, installation, testing, concrete pouring, concrete curing and concrete repair to ensure that all the concrete works are properly executed in accordance with Project Specifications and applicable standards.
2. Definitions
SE Site Engineer
QC Quality Control Engineer
SF Site Foreman
PM Project Manager
SA Site Agent representative from the Lab
HSE Plan Health, Safety and Environment Plan

Note: All dimensions are in mm unless specified. All temperature values are in degree centigrade unless specified.
3. References
Information sources may include, but not be limited to, verbal or written and graphical instructions, signage, work schedules/ drawings/specifications, work bulletins, charts and hand sketches, and Material Safety Data Sheets (MSDS).
1. Excavation Specification
2. Concrete Specification
3. Design Mix
4. Method Statement for Temperature Control and Monitoring for Mass Concrete
5. Method Statement for Blinding Concrete
6. Method Statement for Waterproofing System
7. Welding Procedure for Steel Reinforcement Cages
8. HSE General Requirements
9. Health, Safety & Environmental Plan
10. General Lifting Plan
11. Precast Specialist Specification
12. Material Submittal References:
A. Steel Reinforcement ref.: xxxxxxx
B. Couplers
C. Plastic Spacers
D. Concrete Spacers
E. Stainless Steel Dowel
F. Tie Wires 1.6mm
G. Formwork Release Agent
H. Sealant
I. Epoxy
J. Waterstops
K. Bonding Agent
L. Gauge 1000 approved Polyethylene Sheet
M. Blinding Concrete
N. Structural Concrete
P. Curing Compound
R. Formworks
S. Concrete Repair Materials
13. Calibration Certificate for Survey Equipment
14. Baseline Program

All concrete works shall comply fully with the applicable laws, client’s requirements and specification as per Project Specification.
4. Responsibilities
The responsibility for inspection and testing of concrete works rests primarily with the Site Engineer and Discipline Foreman with assistance from an audit by the Site Agent and Inspectors.
The Site Engineer and Discipline Foreman shall ensure that the required Quality Control procedures and forms are available in place on a daily basis. Similarly, they shall ensure that the needed drawings are of latest revisions.
The HSE inspection shall take place before concrete works start to ensure that the work area is safe i. e. adequate access, adequate illumination if working on night shift, good concrete pump arrangements, checking the formwork and supports, scaffold inspections, if applicable.
Project Manager
Responsible for accomplishing the stated project objectives which include creating clear and attainable project objectives, building the project requirements, and managing the constraints of the project management triangle, which is cost, time, scope, and quality.
The Project Manager shall be responsible for the ensuring that the Project Quality plan and the Inspection and Testing procedures, the method the statement, HSE safety, and all contractual documentation are maintained up to date and accessible to all parties.
Construction Manager
Responsible for overall construction activities ensuring that all method statement, quality and safety procedures are implemented and required approval permits are obtained.
Site Engineer
Supervise operations in accordance with the approved Method Statement, shop drawings, specifications, material submittals and schedules to achieve the acceptance of the project deliverables.
Site Foreman
To liaise with the Site Engineer and Supervisor for the work execution.
QA/QC Engineer
Ensure the proper implementation on Quality system and monitor overall quality of the work is maintained.
Conduct inspection and monitor tests. Determine and report any non-conformance and recommended corrective actions.
Ensure that all personnel is aware of the quality requirement. Training of relevant personnel.
Conduct surveillance and inspection duties at various stages to ensure compliance to QA/QC Plan.
HSE Manager

Health, safety and environmental (HSE) managers generally plan,coordinate and implement issues and directives within the organization. They ensure safe environmental working conditions for all employees.
HSE Officer
Ensure enforcement of safety procedures in accordance with the approved HSE Plan.
Will be closely monitoring the site engineer’s strict implementation of the MS and Risk Assessment, the use of proper tools and equipment to maintain safety, certifications of equipment and their adherence to safety regulations, reporting of any unsafe work or stopping work that does not comply with ES&H procedures.
Will advise on Health & Safety requirements and monitor the Hazard controls implemented on site as per the Method Statement/Risk assessment.
Chief Surveyor
Carry out pre-construction survey to fix the locations and corresponding elevations as per the approved shop drawings.
Ensure the quality and compliance during phases of surveying works and the regular checking of the surveying equipment or periodic calibration from third party.
Ensure validity and serial number of calibration certificates is available and posted in the survey equipment.
Ensure proper safety guarding of surveying equipment.
To maintain the records of all surveying equipment handled.
Survey Aide
Maintain and use Surveying equipment. Assist Surveyors in taking measurements, record measurements manually or electronically, and peg out boundaries.
Equipment Operator
The only authorized person to operate any equipment to be used in the project.
Carpenter
A carpenter construct, erect, install and repair structures and fixtures of wood, plywood, and wallboards using carpenter’s hand tools and power tools.
Helpers /Laborers
Perform tasks involving physical labor at building, assists the skilled workers, remove trash, and residual building debris. Assist in constructing and later disassembling reinforcement braces, concrete forms, scaffolds and temporary structures.
Concrete Batch Plant Supplier
The Plant Manager shall monitor the prevailing Ambient conditions, concrete mix temperature trends etc. to determine the timing to implement the control measures identified in this Method statement, and liaise with the Construction & QA/QC sections accordingly.
The Plant Manager shall ensure that all necessary equipment at the batching plant for cooling the aggregates or chilling water is maintained in good condition and back up plants are similarly maintained.
The Plant Manager shall ensure that aggregates and other constituents material stored with appropriate shading and other measures
implemented as required by this method statement and similar is in the place for back up arrangements.
The Plant Manager shall ensure availability of flaked ice and the like in sufficient quantities for the scheduled concrete works and the backup arrangements are secure.
The Concrete supplier shall propose to the contractor mix designs suitable for Hot Weather concreting and undertake all necessary mix trials and testing in conjunction with the contractor and engineer to obtain necessary arrangement.

5. Interfacing with Other Operations
Limit and Boundary of Work;
Re-routing of existing Temporary Roads
Excavation
Dewatering

6. Duration, Phasing with the Subcontractors
Duration of works shall be as per Baseline Schedule

7. List of Subcontractors
Subcontractor/Suppliers
Ready Mix Supplier – xxxxx (Name of Supplier goes here)
xxxxx (Name of Subcontractor goes here)

II. Resources
1. Plant and Equipment
Transit Mixers and Accessories
Concrete Pumps Concrete Vibrators
Poker or Needle Vibrators
Plate / Surface Vibrators
Wooden Float Steel or Plastic finishing Float
Power Trowel
Mobile Crane
Concrete Bucket
Air Compressor
Leica TS 15m Total Station
Leica NA2 Automatic Level
Shoring / Formwork Material
2. Work Force
Construction Manager
Project Engineer
Site Engineer
Land Surveyor
Survey Aide
Foreman
Equipment/Machinery Operator
Banksman
Steel Fixers
Carpenter
Mason
Rigger As per site requirements
Helpers/Laborers
HSE Engineer
First Aider
3.Light Tools
Power Tools (Various)
Hand Tools (Various)

III. Materials
1. Ready-mixed concrete
2. Steel Reinforcement
3. Plastic Spacers
4. Concrete Spacers
5. Tie Wires 1.6 mm
6. Curing Compound
7. Formwork Release Agent
8. Waterstops
9. Waterproofing Materials
10. Dampproofing Materials
11. Bonding Agent
12. Sealant
13. Epoxy
14. Formworks
15. Gauge 1000 approved Polyethylene Sheet
16. Concrete Repair Materials
17. Water
18. Cement

IV. Site Planning
1. Preparation
a. Contractor shall ensure that all gate passes, permits, tools, materials for safety precautions, manpower and equipment are available before commencement of work.
b. The Site Team shall make sure that access roads are always clear from any obstruction and site is always accessible.
2. Site Clearance
a. Before commencing the work, the area shall be cleared of all debris, materials or other obstructions.
b. Required levels are to be confirmed and verified by Site Engineer and QC Engineer before commencing the work.
c. It is the responsibility of the CM to ensure that any preceding activity is completed.
d. If concrete is required to be done on earlier concrete work, it is the responsibility of the QC Engineer to approve that concrete had hardened (% Strength) enough to withstand a load of reinforcement, formwork, fresh concrete and concrete operations.
3.Traffic Management
a. The Site Team with the assistance of the Safety Officers shall coordinate logistics and materials movement through site following the direction and road signs displayed on site.The required diversion routes shall be marked on drawings including the required traffic signs.
b. The Work Permits and Operator Certificates shall be compiled and files for reference by authorized personnel.
c. Temporary traffic signs, barriers and flagmen will be deployed to control traffic flow in accordance HSE Plan-Traffic Management & Roadwork Construction.
d. Traffic Routing Plan will be submitted before commencing any concreting activity depending upon each work. The plan should be approved by the engineer before the start of work.
4. Pre-construction Safety Meetings
The meeting shall be scheduled prior to the beginning of the work and before any Sub-contractor starts on the project.
a. Safety awareness meetings will be conducted every working day morning/every other day to brief the workforce in the safety prevention measures. The equipment check for safety shall be recorded/ documented during the daily Safety Awareness Meeting.
b. Traffic safety will be discussed to emphasize these meetings.
c. Each worker will be instructed to follow specific safety requirements related to his trade. They will be required to follow installed safety signs, observe barricades and use opens.
d. Contractor Safety Team will perform hazard risk analysis by identifying all steps, hazards identified in those steps, with a focus on the relationship between the work task, the tools and the work environment. After identifying uncontrolled hazards; Contractor will take steps to eliminate or reduce them to an acceptable risk level.
e. General contractual Safety, Health and Environmental requirements.
f. Roles of the contractor, subcontractors, authority representatives and all project workers.
g. Accident reporting requirements.
h. Specific details of the work to be performed along with the use of personal protective equipment.
i. Emergency procedure.
5. Operating Procedures
Site investigation has to be carried out to develop safety precautions and measures prior to the commencement of the work. After such investigation, relevant sign boards will be displayed and barricades will be installed where and as necessary, such as but not limited to the following:
1. Advanced signs e.g. “Work Area” signs will be placed ahead approximately 300 m before the activity zones on both sides of the road.
2. Relevant information, warning and mandatory signs such as Narrow Road Signs, One- Lane Traffic signs, etc. will be placed at approximately 25m from the last advanced signs.
3. Buffer zones and working areas will be cordoned with highly reflective traffic cones/barriers to separate the survey team and workers from the main traffic flow.
4. “One Way traffic ahead” signboards would be placed 90 m ahead of working area in order to notify incoming drivers of the new road layout.
5. Traffic Controllers would be deployed on both sides in order to control “One-way traffic”.
6. Photographs would be taken for information to maintain traffic safety record-keeping.
7. Radio Communication system would be used where normal communication is impossible.
8. After completion of the work, safety cones and barricades have to be removed accordingly.
9. Contractor shall ensure that dumping of excess concrete on-site is not permitted and no concrete wash-out must take place on site. Operators shall be made aware regarding the same. The Method Statement shall be made readily available to all personnel involved in the specific work activity and shall be posted at the work activity location.

V. Methodology

V.1 General
This document applies to all concrete foundation, below ground structure, slab on grade, column, beam, retaining wall, slabs, raft concrete works, precast concrete work, concrete repair work and any structural work where concreting is required.
The concrete works shall be carried out fully in compliance with the Project Specifications All dimensions, levels, construction joints, movement joints, reinforcement dimensions, reinforcement covers, reinforcement splicing, installation of mechanical splices, etc. shall conform to Approved Shop Drawings of the particular structure.
All safety of the concrete works shall conform to the relevant clauses of Project HSE Plan
The Site Engineer and the QA/QC Engineer will be responsible for monitoring receipt of concrete and conduct the sampling and testing of fresh concrete according to the Quality Plan on site. If any field test indicates that the concrete may be deficient, the QC will report this to the concerned Consultant representative at the location immediately. The consultant will review the test results and will take the required action.
The Site Engineer and the QC will monitor the concrete placement and will notify the Site Agent of any unacceptable materials or operations for action.

1. The materials and Mix design must be approved and available at the site. Concrete will be checked according to the tolerances for slump, temperature, strength and durability referring to approved mix design only.
2. Verticality and post concrete dimension check is a must for all elements.
3. Use approved material and store in a dry place, away from the ground, moisture, dirt and other contaminants. The expired material shall be removed from the site.
4. Structural Concrete failed to meet the mix design requirements shall not be used in the non-structural / temporary works unless otherwise approved by the Engineer.
5. Deliver sealants in the manufacturer’s original unopened containers. Expired sealants should be removed from the site.
6. Store Cement and other cementations materials away from moisture above the  ground.
7. The material shall be stored and used following the manufacturer’s instruction.
8. Setting out of work shall be done by surveyor either for concrete or for any activity including formwork which confirms the shape, size and level of the structural element.

V.2 Reinforcement
V.2.1 Material Handling and Storage
1. All steel reinforcement to be used shall be from an approved manufacturer.
2. The reinforcing steel shall be of type 2 high yield deformed bars grade B500B according to BS 4449:2005 + A2/2009 and shall be cut and bent in accordance with BS 8666: 2005. The minimum tensile yield strength for all reinforcing steel bars shall be 500 MPa with a minimum modulus of elasticity of 190 MPa.
(Or this item number 2 will be based upon the steel requirement stated from the Project Specifications)
3. Reinforcement shall be either delivered cut and bend by the approved subcontractor in compliance with approved shop drawing and Bar Bending Schedule or it may be cold-bent at the site.
4. Fabricated reinforcing bars will be delivered bundled, tagged and marked. The tag will have bar size, length, shape code, bar mark and other information printed.
5. The wire shall conform to the requirements of BS 4482.
6. On delivery, bars in each lot shall be legibly tagged by the manufacturer. The tag shall show the manufacturer’s test number and lot number and other applicable data that will identify the material with the certificate issued for that lot of steel.
7. Storage of reinforcement shall be on suitable structures above the ground surface to prevent damage and accumulation of dirt, rust and other deleterious matter. The reinforcement shall be covered to ensure protection from wind-blown dust, condensation and other deleterious materials.
8. On delivery, bars in each lot will be legibly tagged by the fabricator. The tag will show the manufacturer’s test number and lot number and other applicable data that will identify the material with the certificate issued for that lot of steel.
9. The fabricator will furnish three copies of a certification which shows the batch number or numbers from which each size of bar in the shipment was fabricated.

V.2.2 Mechanical Splices
1. Mechanical splices shall comply with EN 1992-1-1 or BS 8666, and shall be used as and where indicated on the Drawings.
2. Details of mechanical splices shall be submitted to the Engineer for approval. Details of the source and suppliers of each type of coupler shall be submitted to the Engineer for agreement and approval.
3. Reinforcement couplers shall be used strictly in accordance with the manufacturer’s written instructions.
4. For bars in compression, the concrete cover to the sleeve shall not be less than that specified for normal reinforcement. For bars in tension, the mechanical coupler shall satisfy the following criteria:
a. When a representative gauge length assembly comprising reinforcement of the diameter, grade and profile to be used, and a coupler of precise type to be used, is tested in tension, the permanent elongation after loading to 0.6fy shall not exceed 0.1mm and,
b. The coupled bar assembly tensile strength shall exceed 287.5 N/mm2 for grade 250 bars, and 483 N/mm2 for grade 460 bars.
5. The use of mechanical couplers of any type or form shall only be as detailed on the Drawings or as instructed by Engineer. Couplers shall conform to the requirements in BS 5400.
6. Where an approved type of reinforcement coupler is used, the Contractor shall carry out tensile tests for three samples of each diameter of couplers to be used for the Works in three months interval or one sample per batch of less than 100 in number or at 1% of the quantity used for the whole Works whichever is the greater as directed by the Engineer.
7. The test shall demonstrate the compliance to BS 4449 and the following requirements:
a. The preferred failure mode of the couplers is a bar-break failure, defined as a failure occurring away from the coupler, at a distance of at least 2 bar diameters.
b. If bar break is not achieved, then the connection shall reach at least 95% of the actual tensile strength of the bar, measured on a control bar from the same batch, and shall have a ductility of at least 5% measured as the elongation at maximum load (Agt).
c. The permanent elongation after loading to 60% yield strength (fy) shall not exceed 0.1mm.

V.2.3 Sampling and Testing
1. Testing of samples shall be in accordance with the Project Specifications following criteria of approved ITP.
2. The sample for testing will be selected randomly from each consignment delivered to site representing different days production of manufacturers work
3. Manufacturer’s certificates will be delivered, stating clearly for each sample:
a.  Place of Manufacture
b.  Expected date and size of deliveries to site
c.  All relevant details of composition, manufacture, strengths and other qualities of the steel.
4. During production, sampling will be done accordingly to BS 4449:
a.  For bend and re-bend tests, nominal mass per meter and surface geometry, one test piece per 30 ton and nominal diameter.
b.  For tensile tests, one test piece per 30 ton with at least three test pieces per test unit and nominal diameter.
5. Other tests for mechanical properties include yield strength, elongation; and for physical properties includes sizes (diameter) and mass.

V.2.4 Reinforcement Fabrication and Placement
1. Before ordering reinforcing steel, the Contractor shall prepare the reinforcement schedules based on design drawing and secure approval of the Engineer. Bar schedules shall show the weight of each bar, the total weight of each bar size and the total weight of bars, and bending diagrams for bars in accordance with BS 8666. Laps and anchorages shall be as shown in design drawing or as approved by the Engineer.
2. The contractor will prepare the cutting and bending of reinforcement which shall be in accordance with BS 8666 and be done without application of heat. Bends shall have a substantially constant curvature.
3. Reinforcement bars shall not be straightened or re-bent without the approval of the
Engineer.
4. Fabrication of reinforcement may be done on site or in the fabrication shop. Depending upon the situation assembling of reinforcement cages shall be done on site.
5. Reinforcement installation in any part of the reinforcement concrete structure shall be securely and accurately fixed in the position shown in the drawings to ensure that the reinforcement steel framework as a whole shall retain its shape. The Framework shall be temporarily supported as to retain its correct position in the forms during the process of placing and consolidating the concrete.
6. The ends of all tying wires shall be turned into the main body of the concrete and not allowed to project towards the surface.
7. The lapped joint shall be indicated on the Drawings and/or in accordance with the requirements of BS 8110.
8. Hook shall be semi-circular with a straight length of at least four bar diameters for mild steel and six bar diameter for high yield steel.
9. Splicing, except where indicated on the drawings or approved shop drawings, will not be permitted without the approval of the Engineer. In case of any welding like fitting of hooks for reinforced cage of pipes, approved procedures (WPS) to be shall be submitted for approval.
10. Approved spacers, chairs and other support shall be provided as necessary to maintain the reinforcement it its correct concrete cover to reinforcement. The spacers will be as per BS8110-1, Clause 7.3 and BS 7973.
11. Only approved spacers through approved Material Submittals shall be used and any other material shall not be allowed.
12. The cover shall not be less than mentioned in the approved shop drawing
Note: The tolerances on the cover layer measured at any point shall be -0/+10 mm on the above dimensions.
13. Placing of all reinforcement steel bars will be checked by the Engineer and in no case is concrete to be placed around any reinforcement steel that has not been approved by Engineer.
14. The reinforcement should be clean & free from loose rust, concrete mortar, oil and or other substances adversely affecting reinforcement, concrete or bond between the two. Rebar shall be protected with polythene sheets.
15. Walking on reinforcement for access purposes will be avoided where possible. Where it is unavoidable any deformation will be removed or repaired prior to concreting.

V.3 Formwork
V.3.1 General Criteria
1. Formwork must comply with the requirements of BS 5975, EN 1992-1-1 and CIRIA Report 136 Formwork Striking Times.
2. This methodology includes permanent forms, temporary formwork, and falsework  for the structural and architectural cast – in place concrete including form lines, coatings and accessories.
3. Wherever applicable submittal shall be made referring to the Project Specifications.
4. The erected formwork shall be watertight from the ingress of external liquids and the egress of internal liquids. Adjustable steel supports and shores shall allow form boards and framework to be accurately adjusted to line and level. The Contractor shall ensure that adequate ground support for falsework is available, and if not shall take measures to make them suitable.
5. Design of Formwork shall be carried out in accordance with CIRIA Report – 108.
6. Contractor shall ensure that the formwork is capable of handling operational load, concrete load in addition to its self-weight. It should be capable enough to maintain the correct position, shape and profile of structure.
7. Particular care should be taken during removal of formwork so that it shall not cause shock, disturbance or damage to concrete.
8. Shores of abnormal height or special requirements shall be specially designed.
9. No loading in excess of the design loading shall be placed on any portion of the structure without the written permission of the Engineer.
10. Mockup shall be carried out on mutual agreement before starting the work and shall remain as part of finished work.
11. Any embedded items shall be placed referring to approved design. Fixing details of embedded items shall be submitted before commencing the work. Fixing design shall ensure the correct position and fixation of embedded items.
12. The contractor shall be responsible to repair any damage to permanent structure in partial or full referring to comments of QA/QC Engineer.
13. All exposed concrete corners and edges shall have 20mm x 20mm chamfers.

V.3.2 Material and Class of Finish
1. Forms shall be of wood, metal or any other material acceptable to Engineers.
2. Erection of formwork shall be carried out in close conjunction with project specifications and recommendation of manufacturers. It should meet the requirements of EN 1992-1-1.
3. Form material showing excessive deformation, holes, surface undulations or any kind of structural or behavioral deformities which proves formworks’ ineffectiveness shall not be used without prior approval of Engineer.
4. Where concrete surfaces are to receive waterproofing membranes, they shall be prepared in accordance with the waterproofing manufacturers written recommendations.
5. The addition of small quantities of water to the finishing trowel will be permitted to aid finishing.
6. Where surfaces are to be painted or sheeted, the formwork shall be capable of achieving a suitable finish.
7. Grooves in the exposed concrete shall be formed by attaching tapered planed timber battens.
8. Form ties shall be factory fabricated, adjustable, removable and capable of preventing deformations. They shall have a factor of safety not less than 1.5.
11. All Void forming material shall be expanded polystyrene with properties referring to Project Specifications.
9. Holes larger than 10mm diameter using snap ties is not permitted. No metal shall be left closer than cover shall be permitted other than embedded Secs as specified in the drawing.
10. Use of form coating shall be in accordance with manufacturer’s instruction and shall not leave any stain, discoloration. It should be nonreactive to concrete.
11. Form coating shall be applied before fixing of formwork in place. Care shall be taken to avoid oil/coating on reinforcement and if found shall be removed before concreting.
12. Precast concrete moulds shall be rigid steel, wood or fiberglass moulds.

V.3.3 Formwork Execution
1. On removal, formwork should form a uniform pattern on the face of concrete.
2. Trial panels shall be cast for formed and unformed surfaces until accepted by the engineer. They shall be retained during the course of work for comparison.
3. Trial panels shall be cast with concrete using the materials, size, plant and concrete mix and methods of placing and compaction proposed for works including dimensions and appearance requirements agreed size by Engineer till the acceptance of trial.
4. No foreign material (any kind of material which is not part of concrete) shall come in contact with concrete. Formwork must be leak proof.
5. Contractor shall verify lines, levels, and measurements before proceeding with formwork erection.
6. Approved sealers/waterproof sealers on the wood form shall be applied after approval.
7. The temporary opening shall be provided for inspection and for removal of water and shall be sealed before placing concrete.
8. If required, for continuous and mass concreting work, form windows shall be provided with prior approval from Engineer. The size of the window should be adequate for tremies, pump hose and vibrators and shall be spaced at maximum 1.8m horizontally and 2.0m vertically. They shall be sealed leak proof before commencing the work at higher level. Size and location of form windows shall be incorporated in Shop Drawings.
9. The contractor shall ensure and take approval of the work of other trades in the forming and setting openings, slots, recesses, chases, sleeves, bolts, anchors and other inserts are provided.
10. No part of concrete work shall be drilled or cut away without prior approval of the Engineer. Any clashes between holes, cast-in items and reinforcement shall be resolved before placing concrete. In no case, the reinforcement bars shall be displaced without approval from the engineer.
11. Contractor shall clear out block out items after concreting.
12. Conduits or embedded pipes shall be located so as not to reduce the strength of the construction. In no case shall be placed in a slab 125mm or less thickness.
13. In walls, the conduits are not spaced closer than three diameters on center and do not impair the strength of concrete.
14. Surface retarders shall not be used on any formwork surface in contact with concrete unless authorized.
15. The contractor is responsible to show dimensional conformities. In mass concrete work, thin sections and/or where required.
16. Pipes and pipe specials through concrete walls shall be positioned correctly. Where not practicable to cast pipes and specials in concrete, box holes shall be formed in the shuttering.
17. The remaining hole around the pipe or the holes due to formwork supports shall be filled with non-shrink epoxy grout or non-shrink concrete.

V.3.4 Formwork Removal
1. The Engineer shall be notified before the removal of the work.
2. Formwork shall not be stroked or stripped unless concrete has attained enough strength to withstand operation load and self-weight.
3. Concrete shall be thoroughly wetter during and immediately after form removal process.
4. Stripping of formwork shall be not be done before below criteria:

S.N.

Type of Formworks

Minimum Period of Stripping
(After the Concrete Placement)

1

Beam sides, walls, and columns

2 days

2

Soffits of slabs (props left under)

7 days

3

Soffits of beams, joists, and girders, (props left under)

10 days

4

Props to slabs

14 days

5

Props to beams

15 days

6 Soffit of Precast beams

7 days

5. Where finished surfaces have re-entrant angles, the formwork shall be removed as early as possible, within the time limits set above, to avoid shrinkage cracks.
6. The formwork shall be carefully stripped to avoid sudden shocks from the removal of wedges or vibration which might cause damage to the concrete.
7. Reshoring to beams and slabs shall be placed immediately after stripping formwork.

V.3.5 Dimensional Tolerances
1. During the regular check, any accumulation of tolerances results in a position which is out of the permissible deviations referring to the Project Specifications or BS 5606, whichever is more stringent shall be considered. The contractor is responsible for remedial measures.
2. The deviations given below are NOT cumulative. They should be checked at each level.

Intended Location / Element Description Permitted
deviation (mm)
Slab Thickness Up to and including 150mm +/- 6
Over 150mm up to and including 600mm +/- 10
Over 600mm up to and including 1m +/- 15
Over 1m +/- 20
Formed elements (Element size in any direction) Up to and including 600mm 8
Over 600mm up to and including 1.5m 10
Over 1.5m up to and including 8m 15
Over 8m up to and including 15m 20
Over 15m up to and including 30m 30
Over 30m (30mm+1)/m
above 30m
Twist elements Up to and including 600mm 6
Squareness of elements (Element size in any direction) Up to and including 600mm 6
Over 600mm up to and including 2m 10
Over 2m up to and including 4m 15
Over 4m (15mm+1)/m above 4m
Element position in

Plan

Eccentricity   of   Foundation   location   with   intended position +/- 30
Eccentricity of element above foundation location with intended position +/- 10
Slab edges related intended position +/- 10
Any slip formed component with intended position +/- 15
Level of elements Intended level +/- 10
Top surface of any foundation +/- 15
Intersecting beam at same level +/- 10
Two points 6m apart 15
Any point under 3m straight edge on floor 10
Cast in fixing In any direction from intended position 10
Verticality of Elements Up to and including 1.5m 5
Over 1.5m up to and including 2m 10
Over 2.5m up to and including 4m 15
Over 4m up to and including 8m 20
Over 8m (20mm+1)/m
above 8m (with max of 50mm)
Bow of elements (Length) Extremities up to & including 1.5m apart +/- 5
Over 1.5m up to and including 3m apart +/- 8
Over 3m up to and including 5m apart +/- 10
Over 5m up to and including 8m apart +/- 15
Over 8m (+/-15mm+1)/m
above 8m (with max of 25mm)
Pre-camber of elements Up to and including 20mm +/- 5
Over 20m up to and including 40mm apart +/- 10
Over 40mm +/- 15
Abrupt  changes  of continuous surfaces where finish is not specified On continuous surface +/- 3
At construction or movement joints +/- 5
Bolts Pre-set Foundation bolt or bolt group when prepared for adjustment (in plan) +/- 3
Pre-set Foundation bolt or bolt group when prepared for adjustment (in elevation – top level) +/- 25
Pre-set Foundation bolt or bolt group when not prepared for adjustment (in plan) +/- 5
Pre-set Foundation bolt or bolt group when not prepared for adjustment (in elevation – top level) +25/-5
Pre-set Foundation bolt or bolt group when not prepared for adjustment (Clearance all around from opening) 25 min
Pre-set Wall bolt or bolt group when not prepared for adjustment (in elevation) +/- 3
Pre-set Foundation bolt or bolt group when not prepared for adjustment (in section (horizontal) – top level) +40/-5
 Precast Elements Shall be within tolerances specified in BS 8110-1 Clauses 6.2.8.3-6.2.8.6 and 6.2.8.8.

V.3.6 Early Loading
1. The Contractor should note that the loading from the falsework and wet concrete, during the construction of a floor, must not exceed the permissible loading on the floor immediately below. Consequently, two of the floors immediately below the one being constructed will need to be used, to share the loading.
2. While propping through two floors, the Contractor shall ensure, that the props beneath the floor last constructed are released over its full extent as soon as the concrete has achieved sufficient strength to support itself plus any superimposed loading, but not sooner than the periods given in Table for Stripping of Formwork. The props shall then be re-tightened so that these may be used to share the construction loading from the floor above.
3. Notwithstanding the requirements of this Section for the removal times for formwork, the following provisions shall apply to an early loading of concrete.
4. Concrete shall at no time be subject to loading including its own weight which will induce a compressive stress in excess of 0.33 of the actual compressive strength of the concrete at the time of loading or 0.33 of the specified 28 d characteristic strength whichever is the lower.
5. If due to this method of construction, the Contractor wishes to place an imposed load on the structure, he shall arrange for additional cubes to be cast at the point of the structure to be loaded and these cubes will be crushed to monitor the compressive strength in accordance with BS EN 12390-3 Compressive strength of test specimens. The Contractor shall submit calculations showing the stresses induced by any proposed temporary loads to be placed on the structure.
6. No superstructure load shall be placed upon finished piers or abutments until the Engineer has given his approval in writing and in no case shall any load be placed until the curing period is complete.
7. Deck slabs of bridges shall only be opened to traffic or construction equipment and plant when authorized by the Engineer and in no case until the curing period is complete.

V.4 Concrete Transport
1. Transportation delivery and handling shall be in accordance with the requirements of BS8500 and BS EN 206-1.
2. Concrete shall be conveyed from the batch mixer to its place in the Works as rapidly as possible by methods which will prevent segregation or drying out and ensure that the concrete is of the required workability at the point and time of placing.
3. The concrete plan shall suite the method of placing concrete so that continuous flow of concrete is available at all times and cold joints can be avoided.
4. The contractor shall ensure that the time between the placing of different lifts or layers of concrete is short enough to prevent the formation of cold joints. Vibration should be done in a way that no cold joint is formed.
5. Discharge of the concrete shall be completed within 90 min, or before the drum has
revolved 300 revolutions, whichever comes first, after the introduction of the mixing water to the cement and aggregates or the introduction of the cement to the aggregates. In hot weather, or under conditions contributing to quick stiffening of the concrete, a time less than 90 min is permitted to be specified by the Engineer.
6. Following precautions are required to be taken during concrete with pump/chute:
a. Check if proper access is available.
b. No shock of the hose is transferred to the formwork.
c. Hose must never reach into the concrete. Any blockage of hose shall be avoided.
d. Grout shall be pumped through for initial lubrication.
e. Initial discharge of concrete shall not be incorporated in permanent work.
f. The slope of chute or pressure of pump shall allow the flow of concrete without segregation.
g. Chute and pump delivery system shall be maintained clean, before and after the work.
h. All the required records of concrete delivery should be furnished following ITP.
7. Copies of all delivery notes shall be submitted to the Engineer in duplicate, on computer-generated forms and shall include at least the following information.
a. name of supplier, serial number of ticket and date
b. truck number
c. name of Contractor
d. name of Contract and location of office
e. grade of concrete
f. specified workability
g. type and source of cement
h. source of aggregate
i. nominal maximum size of aggregate
j. quantity of each concrete ingredient
k. water content
l. time of loading and departure from ready-mix plant
m. arrival and departure date & time of truck
n. date & time of completion of discharge
o. Notations to indicate equipment was checked and found to be free of
contaminants prior to batching.
p. Maximum W/C ratio
q. Estimated free W/C ratio
r. Position in the structure where the delivery is to be placed
s. Information test cube
t. Actual slump and temperature measurement
8. A computerized copy of the delivery note shall be given to the Engineer’s site representative for each load and completion of concrete pouring time and date shall be updated manually.
9. Unless approved otherwise in advance of batching all concrete of single design mix for any one day’s pour shall be from batch plant/s of a single supplier using the same constituents of the mix as approved.
10. Ready-mix concrete shall conform to BS 8500 in addition to GSO EN 206-1, except
materials, testing and mix design shall be as specified in mix design.

V.5 Concrete Casting
V.5.1 Preparation for Pour
1. Before each concrete pour, the Contractor shall give advance notice of at least one day to the Engineer so that an inspection of the concreting may be made at his discretion. Such notice shall provide details of the concreting operation including:
a. The date and time for the Engineer to inspect the formwork and fixed
reinforcement.
b. The location of concreting.
c. The elements to be concreted.
d. The volume of concrete to be poured.
e. The grade of concrete to be poured.
f. Date and start time and expected completion time of the operation.
2. No concreting shall be commenced until the Engineer has approved the formwork,
reinforcement, waterproofing, M&E fixtures (if any) etc. A 24-hour advance notice to
Engineer for inspection prior to concrete pouring.
3. The reinforcement shall be sprayed with the small amount of water before starting the pour.
4. Water will be removed from excavations before concrete is deposited.
5. For night concreting works, the contractor shall arrange adequate suitable lighting.
6. The contractor shall provide safe and adequate access to all the equipment and personnel available for concreting. Logistic Plan for each major pour shall be submitted to Consultant for review and approval.
7. Before depositing new concrete on or against concrete that has set, existing surfaces will be thoroughly roughened and cleaned of laitance, foreign matter and loose particles.
8. Horizontal construction joints shall be given a brush coat of grout consisting of cement and fine aggregate in the same proportion as concrete to be placed.
9. The casting of concrete shall not begin until a sufficient quantity of approved material is at hand to ensure continuity of the work.
10. Kicker sections of walls, columns etc. where used, shall be cast monolithically with the base slab and compacted in such a way that their strength and other characteristics are at least equal to those specified for the whole member. Kickers shall be a minimum of 75mm high generally.
11. For all concrete pours, M&E clearance from the Engineer shall be obtained prior to
commence each pour.

V.5.2 Placing of Concrete
V.5.2.1 General
1. Concrete shall be placed continuously up to/between constructions joint while it is still sufficiently plastic for adequate compaction.
2. Concrete shall be carefully placed in the horizontal layer not exceeding 300mm – 400mm in height to ensure proper compaction. Placement of layers shall be such that each layer can be properly merged into the preceding layer before initial set takes place. In no event shall the depth of the concrete in one layer exceed 80% of the length of the poker vibrator head, and the layer thickness shall always be determined after considering the compaction procedure.
3. For concrete elements where the smallest dimension is ≤600mm, the temperature of the fresh concrete at the time of placing shall be ≤32°C or as per Project Specifications requirement.
4. Concrete shall be allowed to slide or flow or shoveled by any mean if segregation of
constituents is not occurring.
5. Concrete dropped into place shall be dropped vertically. It shall not strike the formwork between the point of its discharge and its final place in the work, and except by approval of the Engineer, it shall not be dropped freely through a height greater than 1.5 m.
6. Cold weather concreting shall be in accordance with EN 1992-1-1 or CIRIA report 678 and ACI 306.
7. In wet weather, the concrete shall be adequately protected as soon as it is placed. No concrete shall be placed in conditions of heavy rains if the total concreting process is not covered.
8. No concrete in periods of dust storms. Special care required against drying winds. Records of delay due to dust storms to be prepared.
9. Before continuing concreting the exposed concrete face shall be thoroughly wetted at constructions joints.
10. Sketches showing concrete pump allocation/traffic management plan will be prepared for each pour & will be monitored by Safety Officer for safe movement.
11. Level pads with cement mortar top levels of the concrete will be established prior to the inspection.
12. The Contractor shall assess the weather conditions immediately prior to pouring concrete in watertight concrete structures and shall if necessary, either suspend placing of watertight concrete or carry out placing during the late afternoon or evening if the weather is considered to be too hot and/or sunny.
13. Records showing date, time, temperature and weather conditions will be established for each concreting.
14. Where permanent formwork is incorporated in the structure, extra care is required, as full compaction of the concrete cannot be checked after the formwork is removed.

V.5.2.2 Foundation Concreting
V.5.2.2.1 General
1. Where concrete is to be placed on the rock, loose, shattered or unsound rock fragments shall be removed. Immediately before placing the blinding concrete the rock surfaces shall be thoroughly wetted so that water is not absorbed from the blinding concrete.
2. Vertical faces of strip footings, bases and slabs may be cast against the faces of excavation provided:
a. Prior approval is obtained
b. The faces are sufficiently accurate and stable
c. Support to faces is withdrawn progressively as concrete is placed
d. Adequate measures are taken to prevent contamination of concrete
e. Faces of the wall must be cast against formwork
3. No concrete shall be placed in a foundation until the extent of excavation and the character of bearing material have been approved and no concrete shall be placed in any structure until the placement of reinforcing steel and the adequacy of the forms and falsework has been approved.
4. Unless otherwise shown in the drawings or specified elsewhere, all concrete placed  below ground level shall have a minimum protection to its outside faces as follows:
a. Underside – Protected by the laying of a grade 1000 approved polyethylene sheeting on the blinding concrete. The sheeting shall be returned up the outside faces of the concrete and suitably sealed.
b. Sides – Coated with 3 coats of an approved bitumen rubber latex emulsion flexible damp and vapor-proof liquid membrane conforming to BRE Digest No.54 as approved.
5. Arrangements for premature stoppage of a pour shall be agreed and in place before work starts. Should premature stoppage of a pour occur, the Contractor shall notify the Engineer and agree with him the extent and timing of any necessary remedial work before the resumption of placing. Coring tests or Non-destructive testing may be required as directed by the Engineer, to verify the quality of the concrete bonding interface.

V.5.2.2.2 Procedure of Work
1. After reaching the formation level, the final level will be controlled and monitored by the Surveyor.
2. The final level of excavation will be trimmed, cleaned, thoroughly compacted and
consolidated.
3. Rollers and plate compactors will be deployed at the formation level to carry out compaction works, as necessary.
4. Any loose, improperly compacted, soft or other unsuitable material which is encountered below or adjacent to structural foundation levels will be completely removed, backfilled with a Class C25 Concrete.
5. After preparation of the surface, installation of earthing shall be done prior to cast blinding concrete.
6. Blinding concrete shall be done as per approved Method Statement for Blinding Concrete Works.
7. The Surveyor shall be responsible for the control and monitoring of the final levels of blinding concrete.
8. After curing and obtaining approval of the blinding concrete, a surface preparation shall be done prior to commencing Waterproofing works.
9. The surface of blinding concrete shall be smooth and even finish with no sharp projections or abrupt steps, clean and free of loose stones or debris.
10. The waterproofing membrane shall be as per the approved material as shown in the approved shop drawings.
11. Approved external/internal waterstops shall be installed for areas of construction joints and expansion joints as per approved Shop Drawings.
12. Upon approval of waterproofing works, preparation for concrete casting shall follow.
13. The installation of formworks and reinforcement shall be done with the strict supervision to ensure damage to the installed waterproofing shall be minimized and/or in any case of damage, location shall be reported to do the repair works prior to move on to the next stage of work.
14. The upturn to the edge of forms shall be installed with sealant from the top of the membrane to avoid grout runs behind the membrane.
15. During installation of reinforcement, inspection shall be done after installation of first layer of reinforcement to point out the damaged areas since it will be difficult to do repair once the second layer of reinforcement was installed.
16. Approved spacers shall be installed prior to install the formworks.
17. Concrete pouring the for concrete thickness of ≥ 600mm shall be considered as mass concrete and shall be done as per section V.5.2.4 of this document and shall conform to the submitted Method Statement for Mass Concreting Works.
18. Kicker sections of walls, columns etc. where used, shall be cast monolithically with the base slab and compacted in such a way that their strength and other characteristics are at least equal to those specified for the whole member. Kickers shall be done as per approved shop drawings.
19. Curing shall be done using approved curing compound and in accordance with section V.7 of this document.
20. All the joints shall be prepared in accordance with section V.5.3 of this document.
21. Throughout the execution of the work, MEP clearance shall be secured.

V.5.2.3 Concreting of Retaining Wall and Vertical Structures
1. All the retaining wall formwork shall be done considering active pressure.
2. Rigidity of formwork shall be ensured by the competent person before starting the concreting operation.
3. One side of formwork shall be installed to ensure installation of steel in the form of steel cages shall be done accurately. Concrete spacers shall be pre-installed prior to lifting and installation of steel cages.
4. Internal face of formworks shall be applied with approved form release agent.
5. Any welding works shall be done as per approved Welding Procedure for Steel
Reinforcement.
6. After inspection and approval of the installation of steel reinforcement, closure of the formworks shall be done. But prior to this, ensure that approved bonding agent is applied.
7. As far as possible horizontal construction / cold joints shall be avoided. Vertical joint shall be provided as per Section V.5.3.
8. Height of each pour shall be limited to 400mm to ensure proper compaction of concrete. In case of narrow section, form windows shall be provided as described by the Engineer following approved shop drawings.
9. Concrete casting shall be done from construction/expansion joint to construction/expansion joint as per approved drawings. Concrete termination at intermediate location will not be acceptable.
10. Concrete compaction shall be done using suitable compaction techniques approved by the Engineer and ensure standby equipment are available at all times.
11. During the casting, periodic checking of the verticality and stability of formworks shall be done.
12. Columns and vertical structures shall have corner chamfers.
13. Vertical concreting shall be cured by approved curing compound as approved by the Engineer.
14. All loose material shall be removed before starting construction joint between vertical members and vertical to horizontal structural connections before proceeding further. All joints shall be prepared following the specifications mentioned in section V.5.3.
15. Any defect in concrete shall be recorded including the severity of defect. Before repairing any defect, the Engineer shall approve the repair procedure referring to suggestions made in section V.11.
16. All column/wall bars extended above top of slab or connecting beams as mentioned in the approved IFC drawings and shop drawings shall be protected from deterioration and rust formation.
17. Throughout the execution of the work, MEP clearance shall be secured.

V.5.2.4 Mass Concreting
1. Mass concreting is considered when the thickness of the member is more than 600mm.
2. The peak temperature of concrete shall not exceed (particularly in mass concreting) 70 degree for a mix comprising of OPC or SRPC (Sulphate resisting Portland cement) and shall not exceed 80 degree for a mix containing MS (micro silica), 60% GGBS (ground granulated blast furnace slag) or 35% PFA (pulverized fly ash).
3. These limits will be checked using CIRIA 660 report when conducting the risk of thermal cracking analysis for each element at early age.
4. The temperature difference from core to surface in a cast-in section shall not exceed the limits mentioned in approved ITP unless it can be demonstrated, by measurement of coefficient of thermal expansion of the concrete to be used, that a higher value can be used without risk of early age thermal cracking. Cooling and/or insulation of the concrete shall be carried out as necessary to maintain the above conditions.
5. If it can be shown to and approved by the Engineer that with the nature of the construction and the concrete mix concerned, a higher temperature will not be detrimental to the concrete performance. When the concrete temperature exceeds these limits, the Contractor shall inform the Engineer and investigate the cause.
6. Prior to commencing any large pour concrete placement (generally > 1m section), the Contractor shall submit a Thermal Control Plan to the Engineer for approval for each mass concrete structure component. The Thermal Control Plan shall be based on the design assumption that cracking of the concrete as a result of heat of hydration shall not occur.
Analysis shall be performed to determine the maximum allowable temperature differentials between the hottest point of the concrete and the exterior faces. The size and sequence of the pour shall be planned so as to minimize the internal and external restraints and associated thermal and shrinkage cracking. The Thermal Control Plan shall include the following:
a. Dimensions of each typical mass concrete placement, including all locations in the
structure to be represented by that placement.
b. Types and dimensions of materials to be used for mass concrete forms and insulation, and time frames for when the concrete forms and insulation will be removed, including time periods for removal and reinstallation of insulation where required as part of the thermal control plan.
c. Assumptions for average ambient air and average surface rock temperature for time period of placement and curing of each typical mass concrete element.
d. If multiple lifts with time delay are proposed, provide lift height and define time delay between lifts.
e. Include a placing diagram showing the typical mass concrete placement sequence and construction joint locations, if any.
f. Identify areas where steep cooling gradients may occur, and how cracking will be
avoided.
g. Predict peak temperature, peak differential temperatures and at what approximate times they will occur.
h. Define allowable time periods for placing or removing insulation and or forms.
i. A summary of the modeling assumptions used in the analysis.
j. Identify contingency operations to be implemented to control the internal temperature of the concrete should the maximum allowable or the maximum allowable differential temperature is exceeded. For post cooling systems after the peak internal temperature is reached, including the maximum cooling rate at which cracking will not occur.
7. Concrete pours may be rejected by the Engineer if temperature monitoring equipment shows that the limits mentioned here have been exceeded.

V.5.2.5 Roof Slab
1. The Surveyor shall prepare the layout by establishing the required elevation such as slab soffits, elevation of top bars, top of slab, etc.
2. The scaffolding shall be assembled below slab soffits. Staging and bracing shall be done as per approved formwork drawings.
3. All connection shall be applied with sealant to minimize bleeding of concrete during pouring.
4. Formwork release agent shall be applied on the internal face of formworks.
5. The reinforcing bar location shall be marked on the plywood for ease of reference.
6. All MEP penetrations and embedded items shall be marked and ensure it is in placed prior to cast concrete. MEP clearance shall be secured prior to cast concrete.
7. The reinforcement shall be installed as per approved reinforcement drawings.
8. The formworks and reinforcement shall be inspected and approved prior to concrete pouring.
9. During concrete placement, competent formwork Supervisor shall be available to monitor and validate stability of installation.
10. The Surveyor shall monitor levels, verticality, and alignment of structure throughout the work.
11. Concrete casting shall only be terminated at every construction/expansion joint.
12. Concrete compaction shall be done using suitable compaction techniques approved by the Engineer and ensure standby equipment are available at all times.
13. Curing shall be done using approved curing compound and in accordance with section V.7 of this document.
14. Any defect in concrete shall be recorded including the severity of defect. Before repairing any defect, the Engineer shall approve the repair procedure referring to suggestions made in section V.11.

V.5.3.2 Construction Joint
1. All kind of construction joints must be as per approved shop drawings.
2. At construction joint location the surface of the completed concrete shall be prepared by spraying, wire brushing or chipping so that it is free from all laitance, scum and loose material and shows a slightly roughened texture and tips of the coarse aggregate exposed.
3. The position of construction joints shall be as shown on the Drawings. When concrete is placed in vertical members, walls, columns and the like, the lifts of concrete shall finish level or, in sloping members, at right angles to the axis of the members, and the joint lines shall match features of the finished work, if possible, or be formed by grout checks. Kickers shall be constructed integrally with the lift of concrete below.
4. Construction joints shall be prepared when the concrete is self-supporting but still
sufficiently green, the formwork shall be removed, as necessary to expose the construction joint, subject to the requirements of curing. The concrete surface shall be sprayed with a fine spray of water or brushed with a stiff brush, just sufficiently to remove the outer mortar skin and expose the larger aggregate without disturbing it. Alternatively where this preparation proves impracticable the hardened surface skin and laitance shall be removed.
5. Approved Stop boards in vertical position are required to be provided at the end of each section of work for single pour.
6. Where slabs, beams and walls incorporate construction joints, panels shall generally be constructed consecutively. Where this is not possible, a gap not exceeding one metre shall be formed between adjacent panels. This gap shall not be concreted until a minimum interval of 7 days has expired since the casting of the most recent panel.
7. The size of bays for reinforced floors, walls and roofs shall be as shown on the drawings but in no event shall they exceed 7.5 m in either direction or 6 m when unreinforced or with nominal reinforcement. The spacing of construction joints shall comply with below requirements:

Construction Maximum Area

(m²)

Maximum

Length

Slabs with major restraints at both ends 100 13 m
Slabs with major restraints at one end only 250 20 m
Suspended slabs with little restraint in any direction 500 30 m
Raft slab with little restraint in any direction 500 30 m
Wall and retaining walls 40 10 m

8. Horizontal construction joints in walls will only be permitted when the wall is continuous with the floor slab. Walls shall be keyed on cast kickers 150 mm high or on the tops of walls meeting the soffits of suspended members.
9. The contractor shall submit the joint layout before starting the work.
10. In no case, construction joint shall be provided in cantilever member or supporting end of structural member supporting cantilever member.
11. Construction joints in slab and beam shall be provided at 1/3 or ¼ of span subject to a maximum spacing of approximately 9m. Where slabs are supported by beam shall be constructed in one operation.
12. The use of surface concrete retarders and bonding agents at construction joints shall be subject to approval. Leaking joints shall be repaired by Contractor.

V.5.3.3 Movement Joints
1. Concrete shall not be placed on both sides of movement joint at the same time unless otherwise approved. Appropriate construction method shall be adopted referring to the details of movement joint in approved drawings.
2. Joint filler forming the gap at the movement joint should be firmly fixed to the first placed concrete.
3. If more than one strip is used the end should be butted closely together and taped to prevent grout leakage thus preventing the closure of joint.
4. Only approved material for joint filler and joint sealants shall be used. Instructions of the manufacturer are strictly to be followed for storage, transportation and in use of materials.
5. Stainless steel dowel bars shall be grade 1.4401 (316) or equivalent when required at the movement joints.

V.5.3.4 Construction of Joints
V.5.3.4.1 Forming Joints
1. Materials for joints shall be used in accordance with the manufacturer’s recommendations or as otherwise stated in the Contract.
2. Joint filler shall be cut to size before fixing and shall be securely fixed in position to the existing concrete surface before concreting. There shall be no gaps between the joint filler and formation.
3. Waterstops shall be securely fixed in position to formwork in such a manner that compaction of the concrete will not be affected. In-situ joints in waterstops shall be made using methods and equipment recommended by the manufacturer.
4. Exposed waterstops shall be protected from exposure to conditions which may affect the waterstop and shall be kept free from rust, hydrocarbons and other deleterious material.
5. Exposed waterstops shall be protected during application of form release agents to avoid being coated. Ends of water bar should be protected from damage.
6. Hydrophilic strips shall be fully enclosed in the concrete section and shall not be positioned in the concrete cover zone and shall be minimum 50mm clear distance from the nearest reinforcement zone. The joints of waterstops shall be glued by epoxy cement in formed recesses. Ends to be joined shall be miter cut and shall be adhered with adhesive.
7. Joints shall be formed in straight lines perpendicular to the surface of the concrete unless otherwise stated in Contract.

V.5.3.4.2 Forming Grooves
1. Grooves for joint sealant shall be straight and shall be perpendicular to the surface of the concrete. The bottom of the groove shall be flat and shall be parallel to the surface of the concrete.
2. Grooves shall be formed by using timber or other approved formers and shall not be formed by cutting back or raking out the joint filler. The grooves shall be located over the joint filler such that the upper surface of the joint filler is entirely contained in the groove.

V.5.3.4.3 Protection of Grooves
1. Before permanent sealing, grooves for joint sealant shall be protected from contamination by a temporary sealing strip or cover or by other methods agreed by the Engineer.

V.5.3.4.4 Sealing Joints
1. The permanent sealing of joints shall be carried out at least 7 days after concreting unless otherwise permitted by the Engineer.
2. Immediately before permanent sealing, timber formers, temporary seals, dirt and loose material shall be removed from the groove and the sides of the groove shall be cleaned and roughened by water jetting, sandblasting or by other methods agreed by the Engineer.
3. Caulking material shall be firmly packed in the bottom of the groove if the joint sealant is not required to extend to the bottom of the groove.
4. Bond breaker tape shall be fixed continuously and evenly along the bottom of the groove for the full width and length of the groove.
5. Concrete surfaces within 75 mm of the edges of the joint shall be masked with tape before the primer is applied and until the sealing of the joint is complete.
6. Primer for the joint sealant shall be applied to the sides of the groove in accordance with the manufacturer’s recommendations.
7. Joint sealant shall be applied between the minimum and maximum drying times of the primer recommended by the manufacturer. The components of the sealant shall be thoroughly mixed in accordance with the manufacturer’s recommendations using a power-operated paddle mixer for sufficient time to produce a homogeneous mass without entrapped air. The sealant shall be dispensed into the groove as soon as practicable after mixing and within the time recommended by the manufacturer.
8. The groove shall be clean and dry at the time of applying the primer and joint sealant.
9. Excess joint sealant shall be removed by using a purpose made finishing tool such that the finished surface of the sealant is between 4 mm and 6 mm below the face of the concrete.

V.5.3.4.5 Tolerances
1. The best fit straight line of straight joints shall be within 25 mm of the specified line. The line of straight joints shall be within 10 mm of the best fit straight line.
2. The best fit curved line of curved joints shall be as agreed by the Engineer and shall be within 25 mm of the specified line. The line of curved joints shall be within 10 mm of the best fit curved line.

V.6 Compaction
1. External vibrators shall not be used without the approval of Engineer in writing.
2. For deep members having a depth more than 300mm shall be compacted with suitable immersion type vibrators whereas horizontal members like roof slabs, floor  slabs, pavement slabs or top layer of raft can be vibrated with plate/surface vibrators for achieving required finish.
3. Layers shall be limited to a thickness of 300 mm – 400 mm to ensure proper compaction. Placing of the following layer shall not be commenced until compaction of the previously placed layer has been completed in the area, where the next layer is to be placed. In no event shall the depth of the concrete in one layer exceed 80% of the length of the poker vibrator head, and the layer thickness shall always be determined after considering the compaction procedure.
4. All structural concrete except self-compacting shall be fully compacted by mechanical vibrators of appropriate type and size to avoid cold joints and honeycombing, reduce segregation, excessive blemishes or other defects in hardened concrete.
5. Concrete shall be thoroughly compacted by vibration during operation of placing. It should be carried out until the expulsion of air has practically ceased in a manner not to cause segregation.
6. Immersion type vibrators shall be capable of having not less than 10000 cycles per minute and external vibratos not less than 3000 cycles per minute.
7. They should be inserted vertically inside the concrete.
8. Vibrator shall penetrate 100mm into the previous layer.
9. Concrete shall not be moved from one place to another by means of vibrator.
10. Vibration of concrete shall not be applied by way of the reinforcement.
11. Over vibration shall be avoided. Vibration shall on no account be continued after water or excess grout has appeared on the surface.
12. During the placing of all reinforced concrete, a competent steel fixer and a competent carpenter shall be in attendance on each concreting gang. They shall ensure the reinforcement embedded fittings and forms are kept in position as work proceeds.
13. Concrete shall be thoroughly compacted in its final position within 30 minutes of discharge from the mixer.
14. Re-vibration of concrete is permitted only if the already placed concrete is workable and responds to means of compaction. Else the old concrete must be hardened and shall be treated same as construction joint.

V.7 Curing
1. The contractor shall ensure that curing shall be done as per approved curing compound. Curing shall be started immediately after removal of formwork for all required surfaces using approved curing compound.
2. For concrete using only Portland cement, the curing period shall be a minimum of four days after casting provided that the full specified concrete strength is obtained. For concrete using PFA/GGBS the curing (sealed type) period shall be a minimum of Seven days after casting. Formwork left in position can be regarded as protection for the surfaces with which it is in contact.
3. Curing shall not take place until all material related to subjected curing (e.g. hessian cloth, polythene sheet, supply of fresh water or curing compound etc.) is available on site.
4. Water, having room temperature shall be used only during formwork removal process.
5. Freshly placed concrete shall be protected from the sun, wind, exposure and excessive drying out by any mean suitable to contractor which is fulfilling the requirements of referred standards.
6. Concrete to be protected, immediately after placing for 28 days from contamination by sea or brackish water, oil, fuel and other deleterious materials.
7. The curing compound shall not be applied if bleed water is forming or is present on the concrete surface.
8. For mixtures with a low to zero bleeding rate, or in the case of aggressively evaporative environments, or both, the curing shall start at early anytime between placement and final finishing of the concrete.
9. Exposed surfaces shall be protected from air blown contamination until 28 days after the concrete is placed.
10. The curing shall ensure that sufficient moisture is present to complete the hydration of the cement. The method of curing shall not:
a. Disfigure permanently exposed surfaces
b. Affect bonding of subsequent coatings
c. Increase the temperature of the concrete
11. During the curing period, exposed concrete surface shall be protected from the direct rays of the Sun.
12. Curing compounds shall be applied in accordance with the manufacturer’s recommendations immediately after any water seen which may develop after finishing has disappeared from the surface and within 2 h of stripping formwork on formed surfaces.
13. Curing compounds shall not be used on surfaces against which additional concrete or other material is to be bonded unless:
a. it is proven that the curing compound will not prevent bond, or
b. positive measures are taken to remove it completely from those areas which are to
receive bonded applications
c. on fair-faced concrete surfaces
14. On pavements and other slab on ground, curing shall ensure that no plastic shrinkage will occur by means of sun shields, windbreaks, evaporation reducers or fog spraying.
15. Mats used for curing can either be left in place and kept saturated for completion of the curing, or can be subsequently replaced by curing compound, plastic sheeting, reinforced paper, straw, or water.
16. Insulation in the form of insulating formwork, insulating blankets and/or other approved insulating materials, shall be left in place until it can be removed without causing thermal distress to concrete in thick sections (typically 600mm or more). The curing period above may then be reduced in proportion subject to approval.

V.8 Hot Weather Concreting
Ref: CIRIA C660: Early Age Thermal Crack Control in Concrete
V.8.1 General
1. The hot weather period shall be defined as starting when the maximum ambient air shade temperature on site exceeds 35 degrees for the three consecutive days. The end of the hot weather period shall be defined as the period when the maximum air shade temperature is below 35 degrees on three consecutive days.
2. The contractor shall establish a calibrated thermometer on site at approved location.
3. All thermometers and measuring equipment shall have a Third Party Calibration Certificate.
4. Hot weather conditions include the existence of one or more of the following conditions:
a. high ambient air temperature
b. low humidity
c. high solar radiation
d. high wind speeds
e. Calculations or experiments showing that the dry bulb temperature of the placed
concrete, taking into consideration the heat of hydration of cement, exceeds 38ºC and
that the rate of water evaporation exceeds 980 g/m² per hour.

V.8.2 Potential Problems Associated with Concreting in Hot Weather
V.8.2.1 Plastic Concrete
1. Increase of Water Demand;
2. Increase rate of Slump loss, tendency to add water at job site;
3. Increase of rate of setting, resulting in difficult handling, finishing and risk of cold joints.
4. Increase of plastic shrinkage
V.8.2.2 Hardened Concrete
1. Decreased 28 day and later strengths, higher water demand, concrete temperatures;
2. Increase for drying shrinkage and thermal cracking;
3. Decreased durability from cracking;
4. Increase permeability;
5. Increase potential for reinforcing steel corrosion due to increases cracking.
V.8.2.3 Avoiding Potential Problems
1. Use concrete materials and proportions with satisfactory records in hot weather;
2. Use cool concrete;
3. Use concrete consistency that permits rapid placement and effective consolidation;
4. Transport, place, consolidate and finish with least delay;
5. Protect concrete against moisture loss at all times, during production, transportation, placement and compaction;
6. Increase the curing period;
7. Cover the concrete after the completion of vibration & finishing as soon as possible

V.8.3 Concrete Placing and Curing
1. Concrete shall not be placed if the shade temperature exceeds 40ºC where the temperature is rising or 43ºC where the temperature is falling.
2. The temperature of each truck of concrete shall be measured using either a glass, dial type or electronic thermometer, just before the placing of the concrete and the temperature recorded on the delivery ticket. The maximum temperature at placing shall apply to an entire load of concrete in the truck or conveyor. The maximum temperature of concrete at the point of placing shall not be more than 32 °C.
3. The contractor shall employ effective means such as pre-cooling of aggregate and mixing water, as necessary, to maintain the temperature of the concrete.
4. The Contractor shall allow for the increase in concrete temperature in the period from dispatch from the plant while in transportation or whilst awaiting placement on Site and take adequate measures to ensure the maximum temperature is not exceeded.
5. During the established hot weather period, Construction team shall plan concreting operation such that no concreting takes place between the hours of 10:00 hours and 17:00 hours in accordance to Section 5, Part 15, Cl 15.3-1 of QCS 2010.
6. In conditions where the ambient temperature is high enough to use water from concrete mix for cooling of reinforcement and any formwork made of metal; aggregate or other material of high thermal capacity shall be cooled with water before concrete is placed.
7. Preparations must be made to transport, place, consolidate and finish the concreting works at quickest time as possible. Moisture corrections done should be recorded and send to Engineer for review before proceeding further.
8. Equipment for placing should be in good condition, with sufficient backup provisions in the event there is problem. Temperature check shall be carried out at the plant on the concrete floor for every 50 m³ produced or every hour whichever is the minimum.
9. Preparation for protecting and curing the concrete should be readily available on site. These should include ample water for moistening, fogging forms and reinforcement. Curing materials should also be readily available for prompt protection for all exposed surfaces from premature drying upon completion of the placement.
10. If surface exhibits cracking while the concrete is still plastic, it shall be re-vibrated.

V.8.4 Controlling Reducing Temperature of Constituent Materials
V.8.4.1 Aggregates
1. Shading of aggregates in feed storage shall be implemented by the Concrete Supplier to ensure consistency of aggregates used for concrete in Hot Weather conditions;
2. Sprinkling the specified temperature of the fresh concrete cannot be achieved by normal method, the use of alternative method such as use of liquid nitrogen should be assessed;

V.8.4.2 Water
1. The following measures shall be implemented by the concrete Supplier to ensure
consistency of water used for concrete in hot weather conditions
a. Chilling of Water before use (temperature must not be less than 5 degrees)
b. Use of flaked ice directly added to the concrete mixer to replace part of chilled water V.8.4.3 Cement
1. The following measures shall be implemented by the Concrete Supplier to ensure
consistency of cement used for concrete in hot weather conditions
a. The use of freshly ground cement at very high temperature shall not be permitted;
b. The cement shall be kept below the temperature which there is tendency of false set;
c. Under no conditions shall the temperature of the cement exceed 68 degrees when it enters the mixture

V.8.5 Reducing Heat Gain
1. Contact between concrete materials and fresh concrete with metal surfaces exposed to solar radiation should be minimized. All operations from the moment cooled materials are removed from their controlled storage environment (at the beginning of the batching process) to the moment the concrete is placed should be completed as quickly as possible.
2. Aggregates in the batching plant hopper and the hoppers themselves should be protected from the sun to the same standard as aggregates in feed storage.
3. It will be beneficial to have it shaded by using screens. The Mixer units should be filled with ice or chilled water before starting operations in both morning and evening and fully discharges before use.
4. The drums of truck mixers may be wrapped with thick hessian and kept constantly wet by sprinkling of cold water during the concreting operations or painted with white aluminized reflective paint.
5. Haulage distances should be kept to a minimum.
6. Reinforcement and steel formwork shall be covered to shade it from the sun 24 hours prior to concreting.
7. Maintain all plant clean and with suitable reflective surfaces and heat insulation as relevant.
8. Keep the batching and mixing plants under shade.
9. Maintain all agitators clean and with a light colored reflecting shade covering the drum or a continuously wet hessian cover on the drum.
10. Keep waiting agitators under shade.
11. Keep constituent materials fully protected against sun radiation at all times.

V.9 Precast Concrete Works
V.9.1 General
1. Before proceeding further with precast concrete procedure, the contractor must submit required documents mentioned in Project Specifications.
2. To ensure that precast components are constructed in accordance with the contractual requirement, the relevant standards applicable shall be identified in ITP.
3. Following fabrication records are required to be kept on site:
a. type and number
b. date of pour
c. concrete test results
d. shop drawing reference number
e. type and duration of curing
f. date of delivery to Site
g. date of fixing in position
4. If the work does not meet the specified requirements of overall process of precast
construction approved by Engineer, the contractor shall at no cost to the employer:
a. Implement removal, replacement, or remedial work
b. Revise procedures or material to prevent recurrence of unacceptable work.
5. Contractor shall be responsible for QC of overall process according to quality plan.

V.9.2 Testing
1. The contractor shall station a qualified technician at the casting site to continuously test, inspect and report on following:
a. that concrete testing is being carried out in accordance with the requirements of Project Specifications and approved ITP
b. check the following and verify conformance with specified requirements and approved shop drawings:
i. all reinforcing bars
ii. all embedded Secs
iii. all formwork
c. check all openings and provisions for coordination with all trades in the Contract as
shown on approved shop drawings
2. The Contractor shall provide facilities and equipment for the conducting of all required tests following approved ITP except for the strength test which should be carried out by an approved independent testing agency.

V.9.3 Delivery, Storage & Handling
1. The structural precast elements shall be removed from the form without damaging or over stressing and stored or placed for transportation on a stable bed that will not allow distortion of the member.
2. Separate stacked members with suitable battens and bracing. Storage instructions for embedded items shall define the storage position, the allowable support points, the maximum height of any stack and any protective measures required.
3. Mark each member with an identifying reference or piece mark, and the date of casting.
4. All piece marks are to be correlated with test reports and plan layouts or erection drawings.
5. The structural precast element shall be transported with sufficient battens, bracing, and supports so as to prevent over-stress by vibration or impact loadings. The Contractor shall submit his proposed method of transportation to the Engineer for approval.
6. Structural precast units shall be stored, handled and transported in a manner that will avoid undue strains, hair cracks, staining, dirt, rust marks, any disfiguration or other damage.
7. The Contractor shall deliver the units from the casting site to the project Site in accordance with schedule and proper setting sequence.
8. Structural precast units shall be stored free of the ground and protected from wind or rain splashes.
9. During fabrication, construction and after erection, the Contractor shall protect the castings to avoid the possibility of damage.
10. Reinforcement cages shall be made up and securely fixed in accordance with the
reinforcement detail drawings to provide adequate rigidity and to ensure that the specified cover and fit within the mould are achieved.
11. Reinforcement not exceeding 12mm in diameter which projects from the face of unit may be bent to facilitate the casting or demoulding of the unit subject to agreement for each case.
12. The reinforcement shall not be rebent to its final position in the structure before the concrete has achieved 2/3 of its specified characteristic strength.
13. For concrete surfaces to be exposed in the finished structure the use of spacer blocks will not be permitted unless agreed with the Engineer.
14. All embedded Secs shall be of stainless steel Grade 316L.

V.9.4 Forming
1. Forms and casting beds are to be firmly seated so as not to deflect or be displaced under concreting or tensioning loads.
2. Correct for thermally induced strains or forces.
3. For member penetrations larger than 150 mm, coring or field cutting is not permitted unless approved by the Engineer.
4. Clean and coat forms with release agent before installation or reinforcing or embedment.
5. For precast concrete cast under factory conditions, the minimum period before removing the formwork shall be at the discretion of the contractor on the basis of the assessed compressive strength of the unit.
6. No unit shall be lifted from the base on which it was cast before the concrete has attained its design demoulding strength and in no case less than 8 N/ mm², and is strong enough to prevent the unit from being damaged, overstressed or distorted giving due regard to the demoulding equipment to be used.
7. Permissible deviations of the formed surfaces are not to exceed tolerances outlined in the PCI Manual 116, with Secs as summarised or modified in Table below:

Description Tolerance
Dimension
1.  Length +/- 5mm
2.  Width +/- 3mm
3.  Thickness Stem +/-3mm; Flange +/-2mm
Embedment or penetration location +/- 0.2%
Straightness +/-3mm for 300cm
End Squareness +/- 3mm

V.9.5 Erection
1. The Contractor’s erection responsibilities include the safe and proper placing, aligning, and leveling of the structural precast elements on the accepted bearing surfaces and affecting their proper fastening.
2. Before placement of the structural precast elements, the Contractor shall survey and maintain all temporary supports shown or required to control alignment and deflection.
3. Temporary supports shall be retained until framing elements braced thereby have attained integral stability in accordance with the design.
4. The Contractor shall install in proper sequence and maintain all temporary supports shown or required to control alignment, deflection and stress levels.
5. The Contractor shall compensate and correct for the misaligning effect of temperature, draw from welding, bolting or erection sequence or grouting.
6. Where permission for welding is given by the Engineer, the following shall apply:
a. welding shall not take place until all adjacent elements to be connected have been aligned, firmly seated and braced
b. control of heat build-up by limiting voltage, electrode size, and rate
c. spalled or heat damaged concrete around weldments shall not be acceptable
7. Joints, gaps, and connections shall be filled with grout as shown on the Drawings and as approved by the Engineer.
8. Place concrete or grout, avoiding segregation, and compact thoroughly to eliminate voids. Ensure that precast units do not move until concrete or grout has gained sufficient strength enough to ensure stability.
9. Erection Tolerances are as follows unless specified in the approved drawings:

Variable from plumb 6mm in 6m run;
12 mm total in a 12m or longer run
Variation from level or elevation 6mm in runs;
12mmin 12m run; maximum 12mm at single locations
Variation from the position in plan +/- 12mm maximum
Offset    in the alignment   of    adjacent members at joints 1.5mm in 3m run, 6mm maximum

10. Field cutting of holes may be done only with the Engineer’s concurrence, and only with power saws or core drills.
11. The maximum hole size shall be 150 mm diameter or as limited by member size or strand location.
12. Any cracks, spalls and sharp corners created by field cutting are to be ground, eased, and patched with epoxy type bonding and patching compounds.

V.10 Sampling and Testing (Based on QCS 2010)
V.10.1 Slump Test
1. Slump tests (and VSI testing when applicable) shall be carried out at the rate of one test per load of concrete delivered to the Site, or one test per 10 m³ whichever is the lesser for the first 50 m³ of concrete then at a rate of 1 slump test for every 50 m³. Slump shall be recorded on the batch ticket for each delivery wherever applicable.
2. In the event of inconsistent slump values, the Engineer may instruct the Contractor to check the slump test on each truck of concrete at the plant.
3. The slump requirements to the Sampling and testing for slumps will be carried out in accordance with relevant Specifications following the ITP and approved mix design.

V.10.2 Concrete Strength Test Sampling
1. All samples and tests will be carried out in accordance with approved ITP and approved mix design.
2. Samples and fresh concrete will normally be obtained from the concrete mixer during discharge for slump tests and cubes.
3. Each sampling will consist of at least 7 specimen cubes; 2 tested at 7 days and 3 tested at 28 days as per relevant specification. Additional samples to be tested at the discretion of engineer.
4. A minimum of one sample shall be taken of each mix every day the mix is used.
5. Samples shall be taken at the average rate of one sample every 30 m³ of concrete or fractions thereof for the first 90 m³, then one sample every 100 m³ of concrete or fraction thereof when continuous concrete production reaches up to 2000 m3 and later of one sample every 200 m³ of concrete or fraction thereof when concrete production exceeds 2000 m³.
6. A test shall be the average of the strength of the specimens tested at the age specified. If a specimen shows definite evidence other than low strength, of improper sampling, moulding, handling, curing, or testing, it shall be discarded and the strength of the remaining cylinder shall then be considered the test result. To conform to the requirements of this specification, strength tests representing each class of concrete must meet the following requirements:
a. The average of any three consecutive strength tests shall be equal to, or greater than, the specified strength, f’c, and
b. When the specified strength is 35 MPa or less, no individual strength test (average of at least two specimen tests) shall be more than 3.5 MPa below the specified strength, f’c
c. When the specified strength is greater than 35 MPa, no individual strength test (average of two specimen tests) shall be less than 0.90 f’c.
7. If works test specimens fail at 28 days, the Contractor shall suspend concreting operations and shall not proceed further without approval. The Contractor shall carry out in-situ testing of the suspect, in the presence of the Engineer. All defective work shall be replaced and retested to the satisfaction of the Engineer.

V.10.3 Testing of Concrete Cube Samples
1. Cubes shall be numbered consequently and marked:
a. Time, date and name of individual
b. Section of work from which samples are taken
c. Mix reference and delivery note number
d. Name of technician
e. And any other relevant information
2. The slump, concrete temperature and air temperature in the shade will be taken and recorded every time cubes are manufactured.
3. When consolidation of concrete is by rodding procedure, the concrete shall be placed in mould at 3 layers of equal height. Rod each layer 25 strokes. Rod the bottom layer throughout its depth. Distribute the roddings uniformly over the cross-section of the mould. For each upper layer, allow the rod to penetrate through the layer being rodded and into the layer below about 25 mm. After each layer is rodded, tap the outsides of the mould lightly 10 to 15 times with the mallet of 0.6 +0.2 kg, to close any holes left by rodding and to release any large air bubbles that may have been trapped. Use an open hand to tap light-gage single-use cylinder moulds which are susceptible to damage if tapped with a mallet.
4. When Self Consolidate Concrete is used, the concrete specimens shall not be consolidated in moulds and it shall be placed in single lift then leveled with minimum manipulation.
5. All samples shall be moulded at jobsite on a leveled surface area to within 20 mm per meter.
6. Immediately after moulding and finishing, the specimens shall be stored for a period up to 48 h in a temperature range from 20 to 26 °C and in an environment preventing moisture loss from the specimens.
7. Specimens shall not be transported or handled until at least 8 h after final set.
8. Transportation time from site to laboratory for final curing and strength testing shall not exceed 4 hours. Specimens shall be protected from direct sun or rapid evaporation and placed on cushion layer to reduce vibration.

V.11 Concrete Repair
V.11.1 General
1. Particular Specifications: 5.16.7
2. Any defect noticed in concrete shall be rectified by methods approved by the consultant and client.
3. This method statement shall be adopted when concrete defects are identified at site after post-concrete work inspection specifically after stripping of formed surface.
4. All materials to be used for repair works shall be submitted for approval thru Material Transmittal.
5. All proprietary materials shall be used strictly in accordance with the materials manufacturer’s instruction and/or recommendations.
6. Curing for Concrete Patchwork: Polyethylene or plastic sheets shall be used to cover concrete patchwork. Unless otherwise specified in the technical data sheets, curing shall be carried out for 2 ~ 3 days. If curing compound/membrane is used, they shall be compatible with the repair products.
7. Concerning equipment, please refer to Section II – Resources, Sec 1. Tools and Equipment.
8. Store unmixed materials in a cool (preferably temperature controlled) environment, avoiding exposure to direct sunlight.
9. Keep equipment cool, arranging shade protection if necessary. It is especially important to keep cool those surfaces of the equipment, which will come into direct contact with the material itself.
10. Try to avoid application during the hottest times of the day, arrange temporary shading as necessary.
11. Make sufficient material, plant and labor available to ensure that application is a continuous process.

V.11.2 Identification of Defects
1. Surface Imperfections
a. Blowholes
b. Form tie rod / bolt holes, cone holds and voids
2. Honey Combing
a. Honeycomb not exposing rebars;
b. Deep honeycomb exposing rebars
3. Cold Joint
4. Cracks
a. The dry/damp crack is identified as per structure elements as below:
b. Cracks equal or larger than 0.20mm on External Walls and Side part of Base Slabs
c. On all other elements
i. Non-structural Cracks equal or greater than (>) 0.20mm, but () 0.2mm
d. Wet Cracks: Wet cracks are type of defects caused by faulty construction work, especially in waterproofing work. Typical locations to be applied in tunnel structure are as follows:
i. Internal surface of external walls;
ii. Horizontal surface of base slabs
iii. Soffit part of roof slabs

V.11.2.1 Crazing
1. Horizontal or Vertical or overhead crazing portion will be repaired by approved type low viscous epoxy resin.
2. Attention to full and proper preparation of the substrate is essential for complete   repair adhesion.
3. Clean the surface and remove all traces of dust, oil, paint, curing compounds, grease, corrosion deposits, algae or any unsound material.
4. The surface should be preferably prepared by using high-pressure water jetting,  followed by thorough washing to remove dust and remaining particles.
5. Oil and grease deposits shall be removed with non-reactive products to concrete.
6. Mixing and application shall be done referring to approved repair Material Technical  Data Sheet.

V.11.2.2 Blowholes (re-profiling 0 to 10 mm deep)
1. Probable Cause/s: Insufficient Vibration, High W/C Ratio
2. Attention to full and proper preparation of the substrate is essential for complete repair adhesion;
3. The substrate should further be ‘roughened’ to remove excess laitance, to expose pinholes & blowholes and to provide a mechanical key for subsequent application of approved material. This is most effectively achieved by the use of proprietary blast media, such that the fine aggregate is exposed but not polished. Where preparation techniques result in voids of greater than 10 mm depth, alternate method and material shall be used as approved material data sheet.
4. Immediately prior to application of approved material, the prepared substrate should be blown clean with oil-free compressed air.
5. Substrate priming shall be done following the procedure mentioned in approved material technical data sheet.
a. Small quantities (up to 5 kg) can be mixed manually but for large quantities special tools referring to manufacture’s procedure shall be obtained and used.
6. Application of repair material shall be done strictly in accordance with manufacturer’s data sheet.
7. Curing shall be followed according to manufacturer’s specifications.

V.11.2.3 Form Tie Rod / Bolt Holes and Voids
1. Probable Cause/s: Sleeves, Insufficient curing
2. Make sure that the substrate surface must be free from oil, grease or any loosely adherent material;
a. If the concrete surface is defective or has laitance, it must be cut back to a sound base;
b. Bolt holes or fixing pockets must be blown clean of any dirt or debris
3. Bearing Plate/Base Plate
a. The underside of the base plate should be clean and free from oil, grease, rust, scale or other loosely adherent material;
b. It may be necessary to provide air pressure relief holes to allow venting of any isolated high spots;
c. If leveling shims are to be removed once the approved grout has hardened, then they should be pretreated with a thin layer of grease
4. Formwork – General
a. Before fixing any formwork, ensure that the area to be grouted is clean.
b. The formwork itself must be constructed to be leak proof, to prevent any possible grout loss. This can be achieved by using foam rubber strip or mastic sealant beneath the formwork, and at any joints in the formwork. It shall, however, also be provided with drain holes and plugs.
c. The formwork should also be constructed in such a way as to keep the final, unrestrained surface area of the grout to a minimum, to avoid problems with cracking at a later stage.
d. It should be fixed in such a way as to allow easy stripping, without causing damage or distress to the grout – particularly if this is to be done whilst the grout is still green.
e. All dirt and debris to be removed from the grout area before the last piece of  formwork are fixed, to facilitate pre-soaking.
5. Formwork – Geometry
a. Pouring side:
Set up so that grout will be poured the shortest distance across the base plate.
Erected a maximum of 150 mm from the base plate edge.
Erected a minimum of 150 mm higher than the underside of the base plate.
b. Open Side:
Set up directly opposite the pouring side.
Erected a maximum of 50 mm from the plate edge.
Erected a minimum of 25 mm from the underside of the plate.
c. Flanking Sides:
Set flush with the plate edge.
Close attention to, grout tightness” of the formwork.
6. Pre-Soaking
a. All concrete surfaces within the formwork area should be saturated with clean, fresh water for several hours prior to grouting.
b. Immediately before grouting takes place, any free water should be removed. Particular care should be taken to blow out all bolt holes and pockets.
7. Mixing
Mixing shall be done as per approved repair material technical data sheet.
8. Placing
a. It is essential that the machine mixing capacity, material supply, and labor availability is adequate to enable the grouting operation to be carried out continuously. This may require the use of a holding tank, with provision for gentle agitation to maintain fluidity;
b. Immediately prior to placement, the mixed grout should be briefly agitated to release any surface tension.
c. Placing shall be done depending upon the thickness of filling referring to approved product data.
d. Any bolt pockets must be grouted prior to grouting between the substrate and the base plate.
e. Continuous grout flow during the grouting operation is essential. Sufficient grout must
be available prior to start, and time taken to pour a batch must be regulated to the time taken to prepare the next one.
f. The mixed grout should be poured only from one side of the void to eliminate the entrapment of air or surplus pre-soaking water.
g. The grout head must be maintained at all times so that a continuous grout front is achieved.
h. When the grout reaches the open side of the formwork, and rises above the underside of the base plate, pouring should continue slowly down the length of the base plate until completed.
9. Finishing
a. Wherever possible unrestrained “shoulders” are to be avoided. These have a tendency  to crack and/or deboned, due to their unrestrained nature;
b. The gap between the perimeter formwork should not exceed 150 mm on the pouring side and 50 mm on the opposite side. It is advisable where practical to have no gap at the flank sides.
10. Curing
On completion of the grouting operation, all exposed areas of grout should be thoroughly
cured. Using approved curing compound, continuous application of water and/or wet hessian
11. In summary along with standard practice, methods described by approved manufacturer shall be followed in strictly.

V.11.2.4 Honeycomb with rebar not exposed and (<) 50 mm deep
1. Probable Cause/s: Impact from Heavy Object; Form Stripping, Poor Vibration, Loss of  Grout.
2. Surface Preparation
a. Attention to full and proper preparation of the substrate is essential for complete repair adhesion.
b. Mark out affected area, then cut back edge of repair to a minimum depth of 10 mm; Break out the repair area to remove all contaminated or damaged concrete to a minimum depth of 10 mm, up to the pre-cut edge of the repair.
c. Fully expose any corroded reinforcement in the repair area and continue until uncorroded steel is reached. It may be necessary to break out the concrete beyond the original repair area in order to achieve this.
d. Oil and grease deposits are best removed by steam cleaning, detergent scrubbing or the use of a proprietary degreaser
e. Fully clean the concrete and steel surfaces to remove laitance, the by-products of corrosion and other contaminants. This is most effectively achieved by proprietary blast media; with particular attention required to both the rear face of the bars and the edge of the repair. The steel bars should be cleaned to a uniform bright condition, and the edge of the repair should be ‘roughened’ to provide a good mechanical key at the substrate interface.
f. Chloride-induced corrosion will further require high-pressure washing with clean water after blasting to ensure complete removal of the corrosive elements.
3. Reinforcement Priming
a. Exposed steel reinforcement should be securely held in place to avoid movement  during application, as this will affect the compaction, build and bond of the mortar;
b. Apply one full, unbroken coat of approved primer and allow drying before continuing. If unsure about continuity of the coating, apply a second coat and allow drying.
4. Substrate Priming
a. For standard repair conditions, thoroughly soak with clean water and remove excess. Apply approved substrate primer by scrubbing into the surface and allow becoming tacky.
b. For priming in other conditions, apply approved primer as per its current instructions. If in any doubt regarding the most appropriate bonding agent, contact the local manufacturer’s office.
5. Mixing and Application
a. It is essential that the approved material is thoroughly mixed and that the temperature of the mixed material should be below the maximum allowable temperature as per approved data sheet.
b. Mixing and application shall strictly follow the approved product data.
c. If sagging occurs on vertical or overhead faces, the compound must be completely
removed.
d. The substrate must be reprised and compound then reapplied in layers of reduced
thickness.
e. Multiple layers can also be used to achieve the desired thickness and profile; but care
must be taken to ensure consistency of inter-coat bond strength.
f. Where multiple layers are to be applied, the surface of intermediate layers should be ‘scratch- keyed’ and cured with wet hessian. Further applications of fresh compound may be applied once the intermediate layer has reached its initial set.
g. It can be finished by striking off with a straight edge and closing with a steel or plastic float. Note that water can be drawn to the surface if ‘overworking’ with the float occurs, and an unsightly finish may result.
h. Damp sponges or plastic floats may be used to achieve the desired surface texture, but care should again be taken not to overwork the surface.
i. Curing of repaired areas should be carried out as soon as possible after the surface has been closed.
j. Approved curing compound should be spray applied in accordance with its current data sheet instructions.
k. In adverse conditions (e.g. windy conditions or ambient temperatures greater than 30°C), supplementary curing in the form of polyethene sheeting, taped down at the edges, should be used.

V.11.2.5 Deep Honeycomb with rebar exposed and (>) 50 mm deep
1. Probable Cause/s: Impact, Rebar space too close, Loss of grout, Poor Vibration, Low slump
2. Surface Preparation
a. Attention to full and proper preparation of the substrate is essential for complete repair adhesion;
b. Mark out affected area, then cut back edge of repair to a minimum depth of 10 mm;
c. Break out the repair area to remove all contaminated or damaged concrete to a minimum depth of 10 mm, up to the pre-cut edge of the repair;
d. Fully expose any corroded reinforcement in the repair area and continue until uncorroded steel is reached. It may be necessary to break out the concrete beyond the original repair area in order to achieve this;
e. Oil and grease deposits are best removed by steam cleaning, detergent scrubbing or the use of a proprietary degreaser;
f. Fully clean the concrete and steel surfaces to remove laitance, the by-products of corrosion and other contaminants. This is most effectively achieved by proprietary blast media; with particular attention required to both the rear face of the bars and the edge of the repair. The steel bars should be cleaned to a uniform bright condition, and the edge of the repair should be ‘roughened’ to provide a good mechanical key at the substrate interface;
g. Chloride-induced corrosion will further require high-pressure washing with clean water after blasting to ensure complete removal of the corrosive elements.
3. Reinforcement Priming
a. Exposed steel reinforcement should be securely held in place to avoid movement during application, as this will affect the compaction and bond of the material;
b. Apply one full, unbroken coat of approved priming and allow drying before continuing. If unsure about continuity of the coating, apply a second coat and allow drying.
4. Substrate Priming – water (standard repairs)
a. Priming with water should take place after the erection of the formwork.
b. Several hours prior to placing the approved substrate primer, the prepared concrete substrates should be saturated, by filling the formwork.
c. With clean water. Immediately prior to application of approved substrate primer, any excess water should be removed via the drainage outlet, leaving the substrate “saturated surface dry”.
d. Different substrate priming shall be selected and approved depending upon defect like chloride contaminated concrete etc. Application of the same shall be done in strict accordance with manufacturer’s instructions.
5. Formwork
a. Formwork should be constructed such that the unrestrained surface area of the repair is minimized.
b. The formwork should be rigid and tight to the substrate to prevent grout loss. Use of silicone sealant, or similar, is also advised around the edge of the formwork.
c. The internal faces of the formwork should be sealed, using the approved release agent, to ensure that water is not absorbed from the repair material by the formwork.
d. The formwork should include suitable drainage outlets for pre-soaking and, when filling the repair ‘bottom up’ (e.g. soffit repairs), should further include provision for air venting to release trapped air as pouring proceeds.
e. There must be suitable access points to pour or pump the mixed material in place
6. Mixing, Placing and Curing
a. It is essential that mixing is done following the approved product data sheet.
b. Limits of the repair geometry should be in accordance with that laid down in the  Design criteria’ section of the approved product data sheet.
c. Placement should be a continuous process, to avoid the formation of a ‘cold joint.
d. If placing by the pump, the pipeline should be ‘grouted’ with a rich cement slurry or mortar, discharging such grout as waste.
e. Pumping of the mixed material should follow immediately after grouting has been carried out.
f. Formwork should be left in place until the cured grouting area has reached a self-supporting, compressive strength, or as otherwise advised by the Engineer.
g. Immediately after the formwork has been struck, all exposed faces of the repair should be thoroughly soaked with clean water to remove residual traces of the shutter release agent.
h. At ambient temperatures above 30°C supplementary curing in the form of polyethene sheeting, taped down at the edges, must be used.
V.11.2.6 Concrete repair work in generally re-profiling over large area where thicknesses are more than 3mm
1. Prepare the surface as mentioned above in Clause 11.2.2
2. Mixing and Application
a. Care should be taken to ensure that the approved product is thoroughly mixed to produce a fully homogeneous, trowellable mortar referring to manufacturer’s specifications.
b. Under no circumstances should part packs be used.
c. Depending upon the product and its workability criteria, the mixed material can be taken directly from the mixing vessel or subdivided onto spot boards for individual applicators.
d. Apply the mix to the substrate using any of the application instruments; such as trowel, scraper, filling knife and squeegee.
e. The freshly placed mix can be overcoated with epoxy coatings after a minimum curing period of 24 hours.

V.11.2.7 Cold Joints
1. Probable Cause/s: Insufficient casting interval time, poor vibration
2. All the steps will be followed as mentioned in Sec “Honeycomb with rebar not exposed and (<) 50 mm deep”.

V.11.2.8 Dry / Damp cracks, early thermal contraction cracks, drying shrinkage
cracks on external wall and side part of the base slab (equal or greater than 0.20mm)
1. Probable clause/s: high water-cement ratio, insufficient vibration, inappropriate curing or nature of concrete
2. All the Dry / Damp cracks injection will be carried out by approved product and after successful completion of injection; all the packers will be removed and the surface will be finished by approved surface finish material.
3. Summary of Application/Injection
a. Identify the nature of the crack and investigate the extent and magnitude of the crack, follows procedure outline below for injection method treatment. Crack width Less than 0.20mm shall not be repaired.
b. If packers are being used, drill holes along the center of crack to accept the packers. The centers should be 1 -1.5 times the depth of the crack, but not more than 300mm.
c. If flanged injection ports are used, using approved material as the bonding agent. Apply approved material at the bottom of the flange along the perimeter. Ensure that the paste will not block the port.
d. When all the ports or packers are in place, apply the said mortar in a strip 20mm wide and 2-3 mm thick between the ports and centered on the crack. The paste should be forced into the substrate to ensure proper bondage. Make sure the paste seals around the packer or port. Allow to cure.
e. Start the injection process from one end of the crack. In the case of vertical cracks the work shall start from the bottom of crack and work upward. Fill the injection gun with the approved material and start injection process.
f. Inject approved material until it starts to flow out to the next port, seal off the port being injected and move on to the next port. Continue with the succeeding ports until the grouting process completed.
g. Allow the approved material to cure, then remove the injection ports and grind off the paste over the cracks if required.

V.11.2.9 Non- structural cracks, e.g. shrinkage cracks or surface cracks equal or
greater than (>) 0.20mm, but (<) 0.5mm
Probable clause/s: High water-cement ratio, insufficient vibration, inappropriate curing or nature of concrete;
1. All the Non-structural cracks which are greater than or equal (>) 0.20mm but less than or equal (<) 0.50 mm; injection will be carried out by approved material and after successful completion of injection; all the packers will be removed and the surface will be finished by the approved material.
2.Summary of application/injection
a. Make V-groove cut all identified cracks. Crack width less than 0.30mm shall not be repaired.
b. Loose concrete shall be removed until the sound, dense concrete is exposed;
c. Wash the surface with clean water and thoroughly saturate the surface of the concrete to provide a saturated surface dry condition.
d. After mixing, the mortar can be applied by hand or trowel to the prepared area. When the mortar has begun to stiff, the surface can be leveled and smooth using screed bar and finishing steel trowel.
e. Proper curing by means of wet Hessian cloth covered by polythene sheet for at least 2 days or used approved applicable curing materials (water pounding is not recommended).

V.11.2.10 Structural Cracks (cracks > 0.2 mm), Deep-seated cracks (beyond rebar
zone) or through cracks larger than 0.2 mm
Probable cause/s: Impact from heavy objects, early stripping of Forms or Shoring, Disturbance while at initial Setting;
1. All the Structural cracks (cracks more than 0.2mm width) which are beyond the re-bar zone or through cracks larger than 0.2mm width; injection will be carried out by approved material and after successful completion of injection; all the packers will be removed and the surface will be finished by the approved material
2. Summary of Application/Injection
a. Remove surface laitance and contaminants from a bond 50 mm wide centered on the crack, using power wire brushing or high-pressure air jetting, Identify the nature of the crack and investigate the extent and magnitude of the crack by making a V groove cut 25 mm deep along the crack line. Remove surface dust & laitance by high-pressure air jetting,
b. Surface cracks extending to bar reinforcement and excess of 0.2mm in width and 25mm in depth shall be injected by a low viscosity resin. While no repair works are required for cracks in the unreinforced concrete section provided that the structural integrity of the concrete is not affected.
c. If crack depth is beyond 25mm, follow procedure outline below for injection method treatment.
d. If packers are being used, drill holes along the center of crack to accept the packers. The centers should be 1-1.5 times the depth of the crack, but not more than 300 mm;
e. Using oil-free compressed air to blow out along the length of crack to remove dust and debris;
f. If flanged injection ports are used, approved material as the bonding agent. Apply mixed approved material at the bottom of the flange along the perimeter. Ensure that the paste will not block the port;
g. Using a nail or piece of wire inserted through the port, locate the port over the center of the crack. When all the ports or packers are in place, apply the said mortar in a strip 20mm wide and 2-3 mm thick between the ports and centered on the crack. The paste should be forced into the substrate to ensure proper bondage. Make sure the paste seals around the packer or port. Allow to cure;
h. Start the injection process from one end of the crack. In the case of vertical cracks work shall start from the bottom of crack and work upward. Fill the injection gun with the approved material and start injection process;
i. Inject approved material until it start to flow out to the next port, seal off the port being injected and move on to the next port. Continue with the succeeding ports until the grouting process completed;
j. Allow the approved material to cure, then remove the injection ports and grind off the paste over the cracks if required.

V.11.2.11 Wet Cracks
Water infiltration through external wall, base slab structure
Probable cause: Faulty construction works, firstly in “waterproofing work” and secondly in “through cracks”.
1. All the wet cracks where water infiltration through external wall, base slab structure; injection will be carried out in two stage by two different materials first is “approved material” and second stage of injection will start by “approved material” when water infiltration will be stopped. After successful completion of injection of both stages remove all the packers and surface will be finished by approved material.
2. Summary of Injection and Repairing for the Wet Cracks:
Method 1
a. Injection packers inserted into pre-drilled holes shall be fixed at intervals along the length of each crack. The distance between each packer will depend upon the width and depth of the crack. Spacing shall be closed enough to ensure that the approved material will penetrate along the crack to the next point of injection. This will normally be between 200mm and 500mm.
b. If practical, seal the surface of the cracks between the packers with approved material,
30 to 40 mm wide and 2 to 3 mm thick. Where applicable, the approved material shall be allowed to cure for 8 hours at 35 °C.
c. The end of the injection hose shall be attached to the lowest packer on vertical cracks or to either end of horizontal cracks.
d. Each crack shall be treated in a single continuous operation and sufficient material shall therefore be made prior to the commencement of the work.
e. When flowing water has stopped re-inject with approved material to give permanent seal.
f. One end of the injection hose shall be attached to the lowest packer on vertical cracks or to either end of horizontal cracks. Each crack shall be treated in a single, continuous operation. Re-inject with approved material, injection pressure should be as mentioned in manufacturer’s product.
g. Remove the packers or nipples and make good any holes or voids with approved material and allow to be cured.
3. Summary of Injection and Repairing for the Wet Cracks:
Method 2
a. Set out for injection holes half the wall or slab thickness away from the crack at 250 to 300mm centers.
b. Drill 10mm dia. injection hose at a 45 deg. Angle to pass through the crack in the center of the wall or slab thickness. Clean out the injection holes with an air pump and 6mm hose.
c. Insert a probe in the lowest or first hole and inject resin. The resin will flow along the injection hole and enter the crack in the center of the wall. It will then spread through the crack in all directions.
d. Inject until resin bleeds from the face of the face of the crack then move the probe to the next hole. Plug the previously injected holes with temporary hardwood plugs. Continue injection keeping a rising head of resin flowing throughout the crack.
e. Inject until the complete crack is totally penetrated and dry. If water stop resin has been used to stop the flow of running water, drill out the same holes and re-inject with the permanent seal resin.
f. Remove all temporary plugs when the resin has cured and close off all holes with epoxy mortar.

VI. Risk Assessment
Please refer to the attached document in Appendix B.

VII. Permit and Licensing Requirements
Please refer to attached Permit to Work on Appendix C.

VIII. Drawings, Diagrams, and Maps
Please refer to the attached document in Appendix A.

IX. Pre-Start Safety Briefing Arrangements
Refer to Risk Assessment in Appendix B.

1. Protective and Safety Equipment
All workers Involved shall be equipped with adequate PPE as stated below:
a. Safety Helmet with Company Logo
b. Safety Boots
c. High Visibility Vest
d. Safety Goggles
e. Hand Gloves
f. Coveralls
g. Remove or take off immediately any clothing that becomes wet. Wash off the concrete with plenty of water and seek for First Aid Treatment, if necessary

2. Information to Personnel
a. Safety Induction
b. Job training
c. Superintendents Notices/Memos
d. Toolbox talks
e. START Card
f. Site specific Risk Assessment shall be briefed to all personnel prior the commencement of concrete works

3. Special Safety Requirements
a. All necessary personal/protective equipment (PPE) as well as harness be provided.
b. Banksman, wearing distinctive vests, shall be assigned to help operators maneuver their equipment.
c. The equipment operators shall possess the required licenses and certificates
d. Generated dust shall be controlled by periodic water spraying.
e. The project safety officer is responsible along with the project zone site engineer for ensuring that all operations are carried out with due regard to the safety of all project personnel & property.
f. All working activity shall comply with Client Safety Procedure.
g. First Aid Material.
h. General management of protection/operation hazards is to be observed.

4. Emergency Procedures

5. Emergency Contact Numbers

X. Supervision and Monitoring Arrangements
1. Construction Manager
He is in charge of all construction activities. Schedule the project in logical steps and budget time required to meet deadlines. Inspect and review projects to monitor compliance with building and safety codes and other regulations.
2. Site Engineer
The Site Engineer shall evaluate the quantity of materials consumed by each trade to be compared against planned quantity
3. Site Foreman
A construction foreman is responsible for supervising the workers and also doing actual construction work. The foreman monitors employees to ensure that the work is done efficiently and within quality standards.
4. QA/QC Engineer
The QA/QC Engineer shall monitor whether the installation works is conforming to the required quality otherwise he shall notify the Site Engineer should he found non-conformance to the ongoing activities. The Site Engineer shall immediately rectify the work to avoid receipt of NCR from the QA/QC Engineer.
5. HSE Engineer
The Safety Engineer shall be full time at the site and shall frequently visit all the ongoing works at site. All safety violations and on-conformance of the HSE Plan shall be registered and immediate action shall be done in coordination with the Site Engineer.
6. Chief Surveyor
A Chief Surveyor ensures that surveying data are collected and recorded accurately and that all company procedures are followed by crew members.

XI. Environment and Quality Issues
1. Precautionary Measure
All precautionary measures shall be briefed to all workers prior to commence activity
2. Disposal Requirements
All waste shall be disposed as per Construction and Environmental Management Plan, ref. no.:xxxxxx
3. Inspection, Test, and Sampling
Request for Inspection and Testing will be submitted prior and after execution of works.
Inspection and Test Plan (ITP) shall be provided.
Refer to Inspection and Test Plan in Appendix D.
4. Quality Assurance Requirements Table
a. Refer to Project Quality Plan
b. Inspection and Test Plan (ITP) shall be provided.

XII. Attachments
1. Risk Assessment
Refer to Risk Assessment in Appendix – B.
2. Reference Documentation
a. Project Specifications
b. Applicable Codes and Standards
3. List of Appendices
Appendix A: Drawings, Diagrams, and Maps
1. Zones and Sections
2. Typical Sections Showing Sequence of Work
Appendix B: Risk Assessment
Appendix C: Permit to Work
Appendix D: Inspection and Test Plan (ITP)
Appendix E: Organizational Chart
Appendix F: Traffic Management Plan

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