The increase percentage of concrete strength is related to the type of cement used and curing temperature, which is under the condition of natural curing without admixture;

Ordinary cement, 7 days old, average temperature 15℃ = 54%, 20℃ = 62%, 25℃ = 68%, 30℃ = 73%, 35℃ = 76%;

With pozzolan cement and slag cement, the average temperature at the age of 7 days is 15℃ = 38%, 20℃ = 45%, 25℃ = 50%, 30℃ = 55% and 35℃ = 63%.