Question

The compressive strength of steel as compared to concrete is __________.
A) 25 times less
B) equal
C) 25 times more
D) 5 times more

Answer 1

Hint: Compressive strength refers to the ability of a material to withstand crushing, i.e., a column or beam made of a material with high compressive strength should easily resist the vertical load on it without causing any damage.

Complete step by step answer:
Compressive strength refers to the ability of a material to withstand crushing. Concrete is a mixture of cement, water, and aggregates and has very good compressive strength but lacks toughness which is the ability of the material to absorb energy and plastically deform before it fractures. Concrete ruptures easily under tension. But this disadvantage can be decreased drastically by embedding bars of high tensile strength in it. This is then termed as reinforced concrete.
Steel is an alloy of iron and carbon. It has very high tensile strength and can resist fractures. It is often used in building large modern structures like stadiums, skyscrapers, etc. Steel bars are commonly used to reinforce concrete.
The compressive strength of steel is about 250 MPa while that of concrete ranges from 30MPa to 80 MPa. So the compressive strength of steel is about 5 times more than that of concrete.

Hence the correct option is (D).

Additional information:
In reinforced concrete, the compressive strength of concrete and tensile strength of steel bars together comprise the strength of the reinforced concrete. Steel bars are used because of their high tensile strength. The most celebrated quality of steel is its high tensile strength. Steel is less expensive when compared to reinforced concrete. But overall, reinforced concrete is considered to be better than concrete and steel.

Note:
Compressive strength refers to the ability of a material to withstand getting pushed together while tensile strength refers to the ability of the material to withstand getting pulled apart.