Question

The width of expansion joint gap is 2.5 cm in a cement concrete pavement. The spacing between expansion joint for a maximum rise in temperature of ${25}^{\circ }C$ (in m, round off to nearest integer) is ___________. (Assuming coefficient of thermal expansion of concrete as $10\times {10}^{-6}per{}^{\circ }C$

Answer 1

Gap at expansion joint,
$\delta =25mm=25\times {10}^{-3}m$

coefficient of thermal expansion,
$\alpha =10\times {10}^{-6}/{}^{\circ }C$

Rise in temperature,
$t={25}^{\circ }C$
$\frac{\delta }{2}=l_e\times \alpha \times t$
$\left(\frac{25\times {10}^{-3}}{2}\right)=l_e\times 10\times {10}^{-6}\times 25$
$\therefore$ Spacing of expansion joint,
$l_e=50m$