WHAT TO INSPECT DURING CONCRETING WORK?

Careful supervision is necessary for all concreting operations such as batching, mixing, transporting, laying, compacting and curing during concrete manufacturing. The following points should be kept in mind for effective quality control while inspecting the concreting work.

inspection during concreting

1. The concrete mix must be designed in the laboratory with the materials used in the field.
2. Wet batching should be adopted as far as possible. Where the facility of load batching is not available, the Engineer-in-Charge may allow volume batching.
3. During mixing, the mixer must be charged to its full rated capacity. The ingredients should be fed in the proper order. Mixer speed should be from 15 to 20 rpm Mixing time should not be less than 2 minutes in any case. Separation should be avoided while unloading the concrete from the mixer.
4. In the plastic state, the workability of concrete is an important quality. This should be checked by deceleration test or compaction factor test. every 25m. About three tests should be done daily for³ Of concrete.
5. There should be no separation during the transportation of concrete.
6. Concrete should not be dropped from a height of more than 1 meter. If the height of the drop exceeds 1 m, chutes should be used.
7. It should be placed as last as possible to avoid re-conducting the concrete.
8. For compaction, a vibrator must be used. The insertion distance of the internal vibrator should not exceed 0.6 m. It should be pulled out slowly so that no holes are left in the concrete. The frequency of the vibrator should not be less than 7000 cycles/min.
9. The curing should be done for a specified period of time so that the concrete can develop the required strength. Once the concrete has hardened, it should be covered with a hessian.
10. The form should correspond to the final form of the work structure. This should be checked before starting the concreting. The inside of the forms should be cleaned and oiled. The forms should be deleted after the specified period.
11. Concrete should be protected from hot and cold weather at an early age. Concreting should not be done at temperatures below 4.50C and above 400C. Water and aggregates should be cooled in very hot weather. Retarders of approved quality may be used.
12. Water and aggregates should be heated in very cold weather. Accelerators of approved quality may also be used.