Question

A concrete highway is built of slabs 15 m long. If the coefficient of linear expansion for concrete is 1.2 x 10-5 K-1, how wide should the expansion gaps be between the slabs to prevent buckling of the slabs when temperature changes from -20oC in the winter to 48oc in the summer?

Answer 1

0.01224 m

Step-by-step explanation:

L = length of the concrete slab = 15 m

α = Coefficient of linear expansion for concrete = 1.2 x 10⁻⁵ K⁻¹

`T_(o)` = initial temperature of the slab = - 20 °C

`T_(f)` = final temperature of the slab = 48 °C

ΔL = expansion in the length of the slab

Expansion in the length of the slab is given as

`\Delta L = L\alpha (T_(f) - T_(o))`

ΔL = (15) (1.2 x 10⁻⁵) (48 - (- 20))

ΔL = 0.01224 m