Civil Engineering - Building Materials - Discussion

Both C3A and C4AF are responsible for flash setting. As the proportion and rate of hydration of C4AF are more than that of C3A, C4AF is responsible for the initial setting time.

The flash setting of cement due to - C4AF,
Initial setting of cement due to - C3A.

1. C3S - The hydrolysis of C3S is mainly responsible for 7-day strength and hardness.

2. C2S - At early ages, less than a month, C2S has little influence on strength and hardness. While after one year, its contribution to the strength and hardness is proportionately almost equal to C3S.

3. C3A - Tricalciumaluminate is responsible for the initial set, high heat of hydration and has a greater tendency to volume changes causing cracking.

4. C4AF - It is responsible for the flash set but generates less heat. It has the poorest cementing value.

I'm agree with you, Thanks @Joey.

I think option A is correct.

Early strength - C3S.
Early setting - C3A.

When water is added in cement, first tricalcium aluminate is reacted with water and it is responsible for initial setting of cement.

C3S - early strength.
C2S - ultimate strength.
C3A - the initial setting of cement.

Heat of hydration C3A > C3S > C4AF > C2S.

Hello guys, the answer is right, because C2S is responsible for early STRENGTH of cement in the INITIAL stage, in this question ask the initial setting time of cement.

Answer C is correct.

Be because.

C3s strenth property.

C3a time &hydration property.