Question

Statement (I): Rapid method of concrete mix-design will take 3 days for trials. Statement (II): This rapid method depends on curing the concrete in warm water at or above ${55}^{\circ }C.$

• A. Both statements - I and statements-II are individually true and statement-II is the correct explanation of statement- I
• B. Both statements - I and statements-II are individually true and statement-II is the NOT correct explanation of statement- I
• C. Statement- I is true but Statement-II is false.
• D. Statement- I is false but Statement-II is true.

Answer 1

The correct option is A Both statements - I and statements-II are individually true and statement-II is the correct explanation of statement- I

Rapid method of concrete mix design reduces the period for finding the strength of trial mixes from 28 days to 3 days only.
Accelerated curing method as per I.S. 9013-1978
$\to$ is Boiling water method in which specimens are cured at $27\pm 2^{\circ }C$ for $23\pm \frac{1}{4}$ hours under standard moist conditions.
$\to$ Warm water methods in which specimens are immersed in water at a temperature of $(55\pm 1^{\circ }C)$ and cured for 20 hours $\pm$ 10min.