Question

What is the minimum grade of concrete in sea-water or which is exposed directly along the sea-coast in the case of plain concrete as per IS code 456-2000?

1. M30
2. M20
3. M40
4. M15

Answer 1

Correct Answer - Option 2 : M20

Concrete in Sea-water (as per IS 456: 2000)

Concrete in sea-water or exposed directly along the sea-coast shall be at least M 20 Grade in the case of plain concrete and M 30 in case of reinforced concrete. The use of slag or pozzolana cement is advantageous under such conditions.

Exposure	Minimum grade of  Plain Concrete	Minimum grade of reinforced concrete
Mild	-	M20
Moderate	M15	M25
Severe	M20	M30
Very severe	M20	M35
Extreme	M25	M40