Designing umbrella-shaped heat-induced channels for oriented heat transfer in asphalt mixtures

Abstract

In order to regulate the directional transfer and collection of heat in pavements, a novel solution has been proposed, named Umbrella-Shaped Heat-induced Channels (UHC). This UHC is composed of carbon fibers with high axial thermal conductivity and a heat-induced layer. A finite element heat transfer model is employed to analyze the heat transfer behaviors of asphalt mixtures. And an indoor irradiation experiment is conducted for feasibility verification. The results indicate that enhancing the thickness of the heat-induced layer or increasing the disparity in thermal conductivity between the heat-induced layer and asphalt mixtures can enhance the oriented heat transfer effect of UHC. The heat-induced layer boosts the horizontal heat flux of the UHC by 60.3% compared to the side without the heat-induced layer. This enhancement is attributed to the secondary thermal convergence effect of the heat-induced layer, which further amplifies the thermal induction and heat collection capabilities of UHC. This phenomenon is crucial for achieving directed heat conduction. The designed UHC can enhance the heat transfer efficiency of the asphalt pavement in the designated direction. Furthermore, it can alleviate the heat island effect, address permafrost thawing and high-temperature rutting issues, and enhance the efficiency of solar energy harvesting on pavements.