Impact of Concrete Thermophysical Properties on Pavement Structural Design: Fid-Bau Portal

Impact of Concrete Thermophysical Properties on Pavement Structural Design

Dehdezi, Pejman Keikhaei

This paper considers the effect of the thermophysical properties of concrete on temperature distributions and stresses developed in concrete pavements. The temperature distributions in concrete pavements, composed of different thermophysical properties, were calculated using a finite-difference model. These temperatures were then fed into a finite-element model as thermal loads in order to calculate tensile stresses in the concrete. It was found that the thermophysical properties of concrete can significantly influence the magnitude of tensile stresses and, subsequently, the thickness of the concrete slab. Concrete with higher thermal conductivity and diffusivity (e.g., incorporating high conductive aggregates and/or metallic fibers) will experience much more uniform temperature and, as a result, a smaller tensile stress will be developed in the concrete. Increasing the thermal conductivity of concrete from $1.2 W / m K$ (concrete containing limestone aggregates) to $3.6 W / m K$ (concrete containing quartzite aggregates and 1% metallic fibers) could result in a 25% reduction of the concrete slab thickness.