The concrete placed at an atmospheric temperature above 40C is considered as hot weather concreting.At this temperature certain special problems are usually encountered.

They are:

1. Rapid rate of hydration of cement, quick setting and early stiffening

2. Rapid evaporation of mixed water.

3. Greater plastic shrinkage.

4. Less time for finishing.

5. Reduced relative humidity.

6. Absorption of water from the concrete by the sub grade andformwork.

7. Difficulty in continuous and uninterrupted curing.

8. Difficulty in incorporation of Air entertainment.

Precautions:

1. Aggregate should be stack piled in shade frequent sprinkling of water should be done to lower the temperature.

2. Cold water may be used to lower the temperature and concrete or use of ice can be done while mixing.

3. Reinforcement formwork and subgrade should be wetted with cold water prior to planning.

4. It is better to do the concreting operations during the evening time when temperature is low.

5. Continuous wet curing is necessary