maximum compression strain in concrete

Question:

As per IS 456:2000, the maximum compression strain in concrete in axial compression is taken as:

A) 0.002 B) 0.0035 C) 0.0025 D) 0.003

Explanation:

According to IS 456:2000, Plain Concrete and Reinforced Concrete Code of Practice (Clause 6.2), the maximum usable compressive strain in concrete in axial compression is taken as 0.002. This value is applicable for design calculations.

The choice of 0.002 as the maximum compressive strain is based on the stress-strain curve of concrete, where beyond a strain of 0.002, the slope of the curve decreases significantly indicating impending failure. Limiting the maximum compressive strain to 0.002 provides a factor of safety against failure in design.

Therefore, option A is the correct answer.

Options B, C and D are incorrect values as per IS 456:2000. The maximum compressive strain of 0.0035 may be achieved in some high strength concrete but 0.002 is specified by IS 456 for design. Options C and D are also not the specified maximum strain values.