Question

A singly reinforced rectangular concrete beam has a width of 150 mm and an effective depth of 330 mm. The characteristic compressive strength of concrete is 20 MPa and the tensile strength of steel is 415 MPa. Adopt the stress block for concrete as per IS 456-2000 and take the limiting value of depth of neutral axis as 0.48 times the effective depth of the beam for considering as a balanced section. What is the likely approximation for the limiting value of the moment of resistance of the beam?

• A. 15 kNm
• B. 25 kNm
• C. 45 kNm
• D. 75 kNm

Answer 1

The correct option is C 45 kNm

$M_{ulim}=0.138f_{ck}b{d}^2$

$=0.138\times 20\times 150\times {330}^2$

$=45.085KN-m$