Question

A singly reinforced concrete beam of 25 cm width and 70 cm effective depth is provided with 18.75 cm2 steel. If the modular ratio (m) is 15, the depth of the neutral axis, is

Answer 1

Answer:

The answer will be 30 cm

Explanation:

According to the problem the width of the concrete beam,w = 25 cm

The depth of the concrete beam, d = 70 cm and area of with steel is ,a = 18.75cm^2

let the depth of the neutral axis be l

Now we know that

0.5 x w x l^2 = m x a x(d-l)

=> 0.5 x 25 x l^2 = 15 x 18.75 x( 70 - l)

=> 12.5l^2 = 281.25(70 - l)

=> l= 30 cm