1. Scope
This method statement is developed and issued to describe the procedure for parapet construction works to ensure that the work is planned and performed in accordance with technical specification and drawings.
2. Responsibilities
- The Project Manager will be responsible for global activities
- The work will be carried out under the responsibility of Construction Engineer & Project Engineer
- Quality Engineer will be responsible for documentation; inspection in accordance with project specification.
- Safety Officer has to ensure that all the activities are carried out in accordance with the relevant HSE regulations.
- Foreman will be responsible for labor productivity
3. References
- Approved construction drawing
- Project Specification
4. Tools and Equipment’s
- Air Blower
- Angle grinder or disc cutters
- Jack hammer (CP222 or equivalent)
- Hand Tools
- Plywood Cutting Machine
- Wheel borrow
- Hand shovel
- Hammer
| Item Description | Quantity |
| Concrete Transit Mixer | As per pace of pouring |
| Concrete Pump | 01 No. + 01 No. Standby |
| Vibrators | 06 Nos + 03 Nos Standby |
| Hand Tools | As required. |
| Concrete Slump Cone & Accessories | 01 Set |
| Thermometer | 01 No. (Digital) |
| Cube Moulds & Accessories | 06 Nos for every 40 m3 of Concrete. |
5. Work Methodology
5.1 Procedural Steps : Rebar’s
Rebar cutting, bending and tying will be based on the Contracts / Shop Drawings. Sketches may be developed at site as identified by Site Engineer for better understanding of the rebar installation sequence.
Delivery Notes, Mill Certificates. Steel Origin, Supplier, Manufacturer and other details of all delivered steel consignments will be checked on Site. The records will be available for consultant reference or any future use. Install rebar’s accurately in position and secure against displacement that might be caused during concrete pouring.
Ensure all embedded items are fixed accurately at required locations and secure tightly against any possible displacement. Any modification done during the installation embedded items shall be indicated in the check sheets as required. Embedded items shall not be supported by Welding to Rebar. Lapping and chairs shall be provided as per the approved drawings.
For every 100 tons in each shipment two samples of each bar shall be tested as per specification (class 2.8 concrete and reinforced concrete)
5.2 PROCEDURE STEPS: FORMWORKS
- Formwork will consist of traditional 18mm Marine plywood faced Shutters.
- Based on the drawings requirements, the Carpenters will fabricate suitable panels and erect in place.
- Construction of formwork will be to the dimensions, shapes and sizes required to obtain the accurate alignment, location and plumb of the finished structure.
- Formwork will be installed ensuring that the shape, size, alignment, level and any other irregularities are maintained within the specified tolerances before and after concrete placement.
5.3 PROCEDURE STEPS: CONCRETE PLACEMENT
5.3.1 APPROVALS / CHECKS
- Concrete placement can only commence upon approval of Inspection request by the Client / consultant.
- Request for inspection shall be submitted only upon approval of QC Engineer and at least 24 hours before the casting schedule.
- Ensure that all embedded items required are installed and secured at their correct location and levels.
- Ensure that all required inspections are performed.
- Ensure concrete is placed and compacted in its final position within 2 hours of addition of water to the mix.
5.3.2 CONCRETE WIDTH (THICKNESS)
The required thickness shall be fixed by providing pre cast concrete spaces and casting level shall be fixed by providing 20mm x 20mm wooden strips on two sides of forms top opening as per the approved plan & specifications and the approved method statement.
5.3.3 PROCEDURE CONCRETE PLACEMENT
Prior to start the walling concrete works the reinforcement, cutting, bending and installation shall be completed as per the specification (civil works concrete and reinforced concrete) and approved by the consultant.
It is also assumed that the form works have been completed as per specification (civil works concrete and reinforced concrete) and approved by the Consultant.
Concrete delivered to site will be as per the approved design mix and checked for slump and temperature. Concrete temperature when discharged in the formwork shall not be more than 300
Structural concrete works can only commence upon completion of the form works and reinforcement activities. Inspection request for pre concreting checks shall be submitted to Client / Main Contractor.
Expansion, Contraction, Isolation, Control and construction joints will be located as shown on the drawings.
Concrete placement sequence will be planned in a manner so that to have minimum re-positioning of the truck mixer or concrete pump.
Adequate number of vibrators, pokers, Hessian cloth, polythene sheets including standby will be ensured. All safety precautions will be followed as per the approved HSE plan.
5.3.4 TESTING OF CONCRETE
Testing of concrete for temperature and work-ability shall be carried out at the site before discharge. After the concrete meets the required temperature and workability cube sample shall be prepared. An area shall be designated near the pouring area for testing and for casting of cubes.
Six cube samples shall be taken for every 100 m3 of concrete for compressive strength test. Additional one sample each set of cubes may be cast to carry out any additional testing requirement if any or as directed by the Consultant. These cubes sample shall be removed from the moulds on the following day and shall be transferred to the approved independent laboratory.
5.3.5 FINISHING OF CONCRETE
The movement of persons on the placed wet concrete shall be avoided as far as possible. Once the concrete surface is touch dry the top surface shall be provided with rough in finishing works. The finished area shall be covered with polythene sheet to avoid rapid hydration. As top of the RC parapet Walls is supposed to receive roof slab, we shall provide rough in finish as instructed by the Siemens Engineer/Consultant Engineer.
5.3.6 CONCRETE CURING AND PROTECTION
Curing of the concrete will began immediately after finishing of the concrete surface and in line with the requirements. By covering polythene sheet immediately after finishing.
Horizontal: After final set has taken place i.e, after 8 to 12 hours, the polythene sheet will be replaced by wet Hessian cloth and covered with polythene sheet. The Hessian cloth shall be kept wet for at least 7 days.
Vertical: Inspect the curing operation effectiveness regularly to avoid any drying of the placed on top of the covers. Ensure damage is not occurred to the polythene sheets by the timber pieces. All vertical surfaces shall be applied with membrane of curing compound immediate after removing shutter
6. Inspection & Testing
Steel inspection prior to start shuttering works and MEP installations..
Final inspection prior to pour concrete.
7. Safety
All safety requirement and hse system safety rules will be followed. The works will be carried out by experienced operatives who will be supervised during the whole of the works. Only experienced trained operatives will operate the equipment. Only authorized personnel will be allowed into the work area. All personnel within the work area will wear the appropriate PPE. (Eye protection, Ear protection, Inhalation protection and anti vibration gloves)
Statutory examinations will be carried out on all equipment with records kept. Only authorized-trained operatives will be permitted to drive any plant or vehicles and mount abrasive wheels on company machines.
Tool box talks will be given to all operatives in the following :
- Protection of the eyes
- Protection of the skin
- Vibration
- Control of Dust Fumes
- Abrasive wheels
- Control of Noise
Cleaning and House Keeping
Upon completion of the day’s work all tools shall be properly cleaned and kept maintained for future use. Site shall be cleared immediately of all debris and wastage. Importance shall be given for housekeeping upon completion of all works
8. Attachments
- Roof parapet Layout and Sections
- ITP & Checklist
- Risk Assessment