Question

Consider the following statements (P) and (Q):
(P): Fly ash and ground granulated blast furnace slag can be used as mineral admixtures in concrete.
(Q): As per IS 456:2000, the minimum moist curing period becomes higher when a mineral admixture is added to concrete.
Identify the CORRECT option from choices given below.
 

• A. Both (P) and (Q) are TRUE.
• B. (P) is TRUE and (Q) is FALSE.
• C. (P) is FALSE and (Q) is TRUE.
• D. Both (P) and (Q) are FALSE.

Hint:

Pozzolanic materials like fly ash and slag reduce the rate of hydration, thus increasing the required curing time to achieve optimal strength in concrete.

Answer 1

The Correct Option is A

Statement (P): Fly ash and ground granulated blast furnace slag are pozzolanic materials and are classified as mineral admixtures. According to IS standards, they are commonly used to enhance concrete properties and are considered artificial mineral admixtures. Hence, statement P is correct.

Statement (Q): IS 456:2000 specifies that when mineral admixtures are used in concrete, the rate of hydration tends to slow down. This requires a longer moist curing period to ensure sufficient strength development.

- Ordinary Portland Cement (OPC) usually requires 7 to 10 days of curing.
- With mineral admixtures, a minimum of 10 days of moist curing is recommended.

Thus, both statements (P) and (Q) are correct, making option (A) the right choice.