The GATE Grind

GATE 2025 CE (CE2) – Question 13

Construction Materials · Concrete: constituents, mix design, short-term and long-term properties · 1 mark · Multiple choice

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.

  1. Both (P) and (Q) are TRUE.
  2. (P) is TRUE and (Q) is FALSE.
  3. (P) is FALSE and (Q) is TRUE.
  4. Both (P) and (Q) are FALSE.

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Show answer and explanation

Correct answer: (A) Both (P) and (Q) are TRUE.

Explanation

Fly ash and GGBS are the common mineral admixtures, so (P) is true. IS 456:2000 (clause 13.5.1) asks for at least 7 days of moist curing for ordinary Portland cement concrete, and at least 10 days when mineral admixtures or blended cements are used, so the minimum curing period is longer and (Q) is also true.