Question

A highway of concrete slabs is to be built in the Libyan desert, where the highest air temperature recorded is 57.8 °C. The temperature is 23.1 °C during construction of the highway. The slabs are measured to be 11.7 m long at this temperature. How wide should the expansion cracks between the slabs be (at 23.1 °C) in order to prevent buckling at the highest temperatures?