A concrete highway is built of slabs 180 m long 20C How wide

A concrete highway is built of slabs 18.0 m long (20°C). How wide should the expansion cracks between the slabs be (at 20°C) to prevent buckling if the range of temperature is -35°C to +35°C?

_____ cm

Solution

he linear thermal expansion coefficient for concrete is a and a = 12*10^(-6) /C

L = aLT

where L is the length, L is the change in length, and Tis the change in temperature

Each block need at least L/2 on either side, plus whatever the neighbor requires for expansion. Between identical concrete blocks of length L, that\'s (L/2 + L/2) = L.

L = 12*10^(-6)*18*(35 - 20) = 0.00324 m

L = 3.24 mm