Question

In a rigid pavement slab of 20 cm thickness, the equivalent radius of resisting section assuming the contact area as $707{cm}^2$ is _______(in cm)

Answer 1

$h=20cm$
and $A=707{cm}^2$ $A=\pi a^2=707$ $a=\sqrt{\frac{707}{\pi }}=15cm$

if a < 1.724 h
Equivalent Radius of resisting section $b=\sqrt{1.6a^2+h^2}-0.675h$

if a > 1.724 h;
$b=a$

but,
$1.724h=34.38cm$
and a < 1.724 h

Equivalent Radius of resisting section
$b=\sqrt{1.6\times {15}^2+{20}^2}-0.675\times 20$
$=14.068cm$