Question

In the context of the IRC 50-2011 guideline for rigid pavement design, consider the following pair of statements.

I : Radius of relative stiffness is directly related to modulus of elasticity of concrete and inversely related to Poisson's ratio

II : Radius of relative stiffness is directly related to thickness of slab and modulus of subgrade reaction.

Which one of the following combinations is correct ?

• A. I : False; II : True
• B. I : True; II : False
• C. I : False; II : False
• D. I : True; II : True

Answer 1

The correct option is C I : False; II : False

l = ${\left[\frac{E{h}^3}{12(1-{\mu }^2)k}\right]}^{1/4}$

as $\mu \uparrow ,1-{\mu }^2\downarrow \Rightarrow l\uparrow$
$\Rightarrow$ radius of relative stiffness and Poisson's ratio are not inversely related
$\Rightarrow$ Statement I is false

$l\propto h^{3/4}$
$l\propto \frac{1}{k^{1/4}}$
$\Rightarrow$ Statement II is also false