Reinforcement checks after fixing
- Check that the spacers and chairs comply with BS 7973: 2001, Part 2, Figures 1 to 9.
- Check that the gap between the reinforcement will allow concrete to fill the formwork.
- It is vitally important that the correct concrete cover is available at kickers otherwise there will be insurmountable problems when it comes to progressing the next lift. Always double check the kicker, before, during and after pouring! This is particularly important where features are present.
- The pre-pour check should pay special attention to the security of cast-in items and that the ends of the tying wires do not project into the cover zone.
- Any loose tying wire to be removed from the rebar.
- Use a timber of the correct size between the rebar and the formwork to check that there is the correct cover.
- Change concrete aggregate size if necessary, where steel is congested. Seek approval first.
- Carry out the checks listed in the Inspection and Test Plan.
- Check reinforcement is fixed properly around openings. Other trades will loosen/cut ties to insert service pipes on temporary works ties etc.
Type of steel, its location, cover, diameter and spacing to be in accordance with drawings and specification. Special attention should be given to the support of, and cover to, top reinforcement in a slab, beam, and especially a cantilever.
Laps and splices
Laps to bars, and splice bars between prefabricated sections to lie in correct position and plane. This can affect space available for the passage of concrete and vibrator.
Rigidity of reinforcement
To be adequate when considering placing and compaction of concrete. In slabs use additional numbers of spacers and chairs especially in those areas where walkways or barrow runs are planned.
No mould oil or paint on bars. No mud or mortar from masonry operations. Cement grout, if clean and diffi cult to remove may remain. No water in bottom of formwork. All debris, particularly tying wire clippings to be removed from the formwork as they cause rust staining.
Use temporary links or wooden templates on column starters.
Cranks in vertical column reinforcement should have some links in their length to maintain cranks in their correct alignment. ‘Flexible’ detailing should be used in preference to cranted bars.
Wherever possible check on any surplus reinforcement.
Check overall dimensions, wall and slab thicknesses, and column cross-sections.
Props, struts and braces
These to be adequate for the size and span of members, and method of placing the concrete.
Correct any displaced bars, distorted cages or formwork.
Check that daywork joints are placed in the best position and firmly fixed.
Ensure vibrator is ready for use and its size suits the spacing of reinforcement, and that it works before placing the concrete.