Paper by HILLER SPRINGENSCHMID FLEISCHER from ISCR 9th 2004 Instanbul Turkey
Concrete pavements which are placed during hot summer weather conditions, harden on the top side, due to the solar radiation, at higher temperatures, as is the case for the bottom side. As soon as the concrete cools down at the top side during the first night, the concrete pavement tends to curl upwards because of the surface near thermal contraction. Substantial zero stress temperature gradients and large slab dimensions thus lead to high flexural stresses. For wide pavements with non-uniform distances between longitudinal joints, longitudinal crack development is favoured. To prevent such cracks an intense heating of the concrete surface must be avoided. A systematic investigation of the temperature distributions within concrete pavements at different curing conditions and the corresponding deformations revealed a significant influence of the temperature during the curing process and of the time of paving when considering the risk of a crack development at an early age.