Question

What is the minimum grade of concrete recommended in coastal areas according to IS 456:2000?

• A. M20
• B. M25
• C. M30
• D. M15

Hint:

For durability: \[ \boxed{ \begin{array}{c|c} \text{Exposure Condition} & \text{Minimum Grade} \hline \text{Mild} & \mathrm{M20} \text{Moderate} & \mathrm{M25} \text{Severe / Coastal} & \mathrm{M30} \end{array} } \]

Answer 1

The Correct Option is C

Step 1: Recall the durability requirements of IS 456:2000. Concrete exposed to coastal or marine environments requires higher durability because of chloride attack and severe exposure conditions.

Step 2: Identify the recommended minimum grade. As per IS 456:2000, the recommended minimum grade of concrete for coastal exposure is \[ \boxed{\mathrm{M30}.} \] Hence, \[ \boxed{(C)} \] is the correct answer.