Question

What is the value of flexural strength of M 25 concrete:-
1. 1.75 M Pa
2. 3.0 M Pa
3. 4.0 M Pa
4. 3.5 M Pa

Answer 1

Correct Answer - Option 4 : 3.5 M Pa

Concept:

Flexural strength of concrete/ Bending tensile strength of concrete/Modulus of rupture of concrete (fcr) is given by,

\({f_{cr}} = 0.7\;\sqrt {f_{ck}}\)

where,

fck = characteristic strength of concrete

Calculation:

Given,

M 25

\({f_{cr}} = 0.7\;\sqrt {f_{ck}}\)
\({f_{cr}} = 0.7\;\sqrt {25} = 3.5\;N/m{m^2}\; = 3.5MPa\)