Question

What is the modular ratio to be used in the analysis of RC beams using working stress method if the grade of concrete is M20 ?

• A. 18.6
• B. 13.3
• C. 9.9
• D. 6.5

Answer 1

The correct option is B 13.3

As per $\text{IS: 456-2000}$ modular ratio is given by
$m=\frac{280}{3{\sigma }_{cbc}}$
For M20 concrete ${\sigma }_{cbc}=7N/m{m}^2$
$\therefore m=\frac{280}{3\times 7}=13.3$