The period developed when the mean day to day temperature falls below 40 C for more than three consecutive days is called cold weather and the concreting done in that period is referred to as cold weather concreting. However, special conditions are to be maintained when finishing, placing, curing, and protecting concrete from severe weather conditions. As during winter conditions can change abruptly, better planning in execution of the work is essential.
When concrete is in plastic state and it freezes, then strength reduces by 50% which in turn affects its durability and workability. Hence, it should be protected from freezing until it attains a minimum of 3.5 MPa.