Enhancing heat release of asphalt pavement by a gradient heat conduction channel

Abstract

In order to enhance the heat transfer efficiency in asphalt pavement along a directional way, a gradient heat conduction channel structure (GHCC) was suggested and analyzed in this paper. The designed structure could gather heat from asphalt pavement into the channel and quickly transfer it to its subgrade along the axis of these channels in the pavement. Thermal analyses of GHCC were performed by a finite element method. The results showed that the maximum heat release of pavement with GHCC could be increased by 11.5 times. And the pavement temperatures at the upper surface and 4 cm were reduced by 2.1 °C and 6.1 °C, respectively. And the maximum downward heat transfer efficiency of the structure could be increased by 17.6 times. A strong horizontal heat flow was observed which was caused by a significant heat exchange between the channels and the surrounding asphalt mixtures. In order to verify the laboratory cooling effect of the structure, a laboratory irradiation experiment was also employed to verify the principles and models of the GHCC. All of these analytical tests showed that establishing the GHCC in asphalt pavements is a promising method to enhance heat release efficiency, endowing asphalt pavement with more active cooling function.