The initial tasks required when carrying out reinforced concrete works will normally consist of excavations, then blinding (creating a strong level surface for the underside of a mass fill or concrete wall/slab)
The Methods are:-
Once excavations have been completed blinding will be poured onto a compacted base of crushed stone.
Formwork will be erected to form the correct profile. The mass fill/blinding will project a minimum of 300mm beyond the outside edge of the structure. The mass fill will be vibrated using an electric poker unit.
Other areas may be made up with granular stone fill to the correct level, then 75mm of blinding concrete placed in accordance with the project specifications.
The concrete will be placed by skip or machine bucket and tamped using a timber screed and then finished with a wooden float.
Engineers will set out the main outline of the structure and all internal walls using Hilti nails hammered into the blinding concrete. Datum’s will be given for fixing wall reinforcement using insulation tape fixed to the main steel at an appropriate level. At all times these datum’s will correspond to ‘concrete’ levels, with the steel fixer making the correct allowance for cover. The datum will correspond to the top of the insulation tape.
‘Box outs’ for pipes/openings etc. will be marked by the following method. The centre line of the pipe will be marked on the concrete surface below, i.e. on the kicker. The level of the centre line of the box out will then be marked using insulation tape on the main bars. It will then be possible for the steel fixer to cut out the reinforcement to the correct size. Trimmer bars will then be fixed to each face.
For base reinforcement it is proposed to use lengths of proprietary strip block.
The steel fixers will select the bundles of steel for the required area. The crane under the control of a qualified banksman will lift the bundle to the required area where it will be fixed to line and level.
At all times fixers will wear the correct PPE. When cutting reinforcement with disc cutters safety goggles and gloves will be worn at all times.
All work at heights or where there is a danger of an operative falling will be carried out of scaffolding.
This is extracted from our Method statement for reinforced concrete available HERE with instant download.