Experimental analysis of thermal conductivity of semi-rigid base asphalt pavement

Thermal conductivity is an important feature of asphalt pavement. However, because of the lacking of a proper experiment device, the experimental analysis of the thermal conductivity of semi-rigid base asphalt pavement is difficult. According to the slab method and Fourier’s heat conduction law, an experiment device is developed to examine the coefficient of thermal conductivity of granular mixtures stacked in large volume and help understanding the thermal conductivity of asphalt pavement. This device is used to examine the thermal conductivity of both asphalt mixtures and cement-stabilised aggregates based on Guang-ba motorway construction. The experimental results show that the coefficient of thermal conductivity of both asphalt mixtures and cement-stabilised aggregates linearly increases with the temperature growth. In general, the asphalt mixtures have better thermal conductivity than the cement-stabilised aggregates. In terms of asphalt mixtures, the void ratio heavily affects their thermal conductivity and the aggregates have larger contribution on the thermal conductivity than the binder. In terms of cement-stabilised aggregates, the most important factor of thermal conductivity is the void ratio, followed by gravel size Also the heat conduction of the asphalt pavement is often instantaneous rather than stable.