Figure 1: Five different curing conditions. Conditions: (A) under standard curing condition for the whole age; (B) under standard curing condition for the initial 0.5 d, then at 45°C for 7 d, and thereafter under standard curing condition until testing age; (C) under standard curing condition for the initial 1 d, then at 45°C for 7 d, and thereafter under standard curing condition until testing age; (D) under standard curing condition for the initial 1 d, then at 45°C for 3 d, and thereafter under standard curing condition until testing age; (E) immediately at 45°C for 3 d and then under standard curing condition until testing age.