- Purpose of Work
This work procedure describes the method to be adopted for Concreting Work at Ramp Slab as shown in the drawings and as directed by the engineer in charge. - Reference
Contract Specification.
o C45/20 OPC (210kg)+50% GGBS(210kg)
Applicable drawings.
o DM Approved drawing - Equipment’s Required
Concrete Placer Pump with 42m arm length – 1 no. working ( 1 no. standby)
Concrete Vibrators with needles – 3 nos. 40 needle( 1 no. 40 needle standby)
Air compressor -1 nos.
Power Floater – 2 nos. ( 1 no. Standby)
Survey Instrument / Dumpy level & leveling Staff
Required Cube Molds ; 10 cube molds for 80 m3
Slump Test Accessories/ Temperature Machine – 1 set
Hessian Clothe for Curing - Man Power Deployments
Staff Details:
Project manager
Project Engineer
Q/A –Q/C
Surveyor
Safety Officer
Gen. Foreman
Concrete Foreman
Shuttering Foreman
Labour Details:
Mason – 5 nos.
Helper – 10 nos.
Shuttering Carpenter – 2 nos.
Steel Fitter – 5 nos.
Electrician – 1 no.
Plumber – 1 no.
Flagmen – 2 nos.
2 - Method / Procedure :
The formwork & reinforcement will be offered for Client/ Engineer inspection before commencement of concrete.
Upon clearance from Consultant’s Engineer, each concrete truck shall be dispatch within 90 minutes from the Batching time.
Approved surface and central water stoppers shall be fixed in external and internal walls respectively and this will be fixed as per manufacturer specifications before concrete.
Concrete temperatures are recorded for each truck load of concrete and concrete temperature shall not exceed 30 ºC at the time of placing. ( Due care will be taken during summer to keep the concrete temperature with in specified limits).
Slump will be taken for every truck and recorded to comply with the approved concrete mix design ie. 150mm +/- 25mm.
Concrete cubes will be made in the ratio of 6 cubes per 100cum of concrete, shall be properly marked and cured for the cube crush test. Cubes will be crushed in the laboratory at 7days & 28 days to check for the compressive strength of concrete..
As shown in the drawing plan, we required One ( 1) Concrete Pump designated in different locations and area of pouring (as shown the sequence of pouring/casting from designated Concrete Pump).
Casting will be group into 1 group as shown on the attached drawing plan.
It should be starts at the starting point of the ramp from the Basement 2 (B2) with the offset width / strip width of 1.5m and onwards to control the flowing of concrete down to the lower part. Need to provide distance allowance for the concrete to flow and need to control the pouring of the pump.
Compaction will be done immediately after pouring using vibrators. Concrete shall be vibrated immediately after pouring.
Petrol vibrators of frequency 8000 cycles/minute, and 40 mm in diameter for normal use.
Formwork fixers & materials shall be made available stand-by during concreting operations.
Hessian shall be kept wet by adding water or by ponding.
A separate pouring sequence including positioning of concrete placers, rate of pour, location of concrete truck inspection, cube casting etc will be prepared and submitted separately for major pours.
Formwork to the sides of concrete surface (vertical sides) shall be removed after 12 hrs and the vertical sides will be kept wet by wrapping with wet hessian cloth.
After required finishing, cover it with polythene sheet for further dust protection.
3 - INSPECTION PROCEDURES:
Inspection Test Procedures shall be according to the QA/QC Inspection & Test Plans.
Upon completion of formwork & rebar the relevant inspection points are checked by Client/Engineer representative and cleared for concreting.
Attached copy of pour card and slump, temperature record will be maintained. - STRIKING/REMOVAL OF FORMWORK
Stripping of forms, supporting props above and below ground shall be confirmed with respect to calculated strength from the tests performed on field cured cubes. Forms will be removed in such a manner as not to damage the concrete but only after the concrete has gained sufficient strength to support itself. - SAFETY REQUIREMENT
Well trained, experienced and appropriate personnel shall be deployed to carry out jobs and experienced supervisors the jobs.
Appropriate personnel protective equipments like gloves, goggles should be worn apart from the safety shoes and helmets which are mandatory.
While placing the concrete out of direct line sight of pump, crane or delivery truck operator a suitable experienced person shall be present till concreting is finished.
The platform should be properly supported by standard scaffolding tube made up of steel, with out any cracks, splits and surface flaws.
Hand rails at the height of 1m from the edge of the board shall be provided at the free ends of platform.
Working platform shall be kept clean at all times and under no circumstances should they be utilized for stockpiling of materials. - ENCLOSURES
Pour card
Slump and temperature record.
