In our country temperature will raise upto 40-50 oC during summer months such temperature is combined with high wind velocity and low humidity enhance the rate of evaporation of water, increases the rate of hydration of cement, these factor reduce the setting time of concrete considerably and adversely effect properties of hardened concrete. Concrete placed at high temperature is prone to excessive contraction due to rapid evaporation of water; there is increased drying shrinkage, which tends to developed cracked soon after placing even before hardening is complete. The quality of concrete mixing water in unit of concrete is decided by the workability desired beside the maximum size of aggregate. To obtain the high workability more water by evaporation of is required, due to accelerated hydration of cement & loss of water by hydration the concrete is prone to loss the workability & to maintain the required consistency water content will hence to increased but merely increasing the water content without increasing the cement content will result in decrease strength and durability.
Effects of Hot Weather Concrete
There are the many effects of concrete in hot weather, first of all the strength of the concrete is reduced due to the reduce of the amount of water through evaporation, highly effect the strength, durability and permeability of the concrete, it also effects the health of the people who are working the so hot weather, so it is so important that concrete should not be done in the hot weather, it should be avoided untill or unless it is so much important. In such situations try to do the concrete work at night time as it was told before.