Plain Concrete

Plain concrete is used in wall foundations, floors, plank protection, drains etc. However, great care is required into preparation, placing, compaction and  curing. As far as the quality of materials and their storage is concerned, these details have already been  given in Section so the same will not be repeated here. In this section plain concrete details are being given with reference to its use in wall foundations. 

Checklist 

1. Lay concrete in even layers Of not more  than 15 cms thick 
2. Insist on labour being properly organised 
3. See that proper proportions &e being used and necessary measuring boxes are accurate and materials are in accordance with specifications. 
4. Ensure that  water content is correct and never  permit additional water once mixing is completed. 
5. Never allow further ramming, beating  or  smoothening after cement has  under its initial set. It is a safe rule to finish all activities with 30 minutes after adding  water to cement. 
6. Do not allow concreting in extreme weather conditions like very hot or very cold. 
7. Cement concrete should be cured for at least 10 days and lime concrete for four days. Special care should be taken in hot, day climate by keeping the surface wet continuously. 
8. In case the foundation concrete is lime concrete or cement lime concrete, then ensure that proper slating tanks exist and that there is proper  mortar mill for making lime mortar for adding to the aggregate. Mortar mill, however, is not necessary when hydrated bagged lime is used. 
9. Ensure all cement concrete is mixed in mechanical concrete mixers. Small hand operated mixers are also available for small works. 

The stage wise details of supervision checks are given in the next section on reinforced Concrete.