Establish directional heat induced structure based on a grouting compound gradient thermal conductivity method

Abstract

In order to control directional heat induced efficiency and reduce pavement temperature, a grouting compound directional heat induced structure (GC-DHIS) was proposed and analyzed in this paper. The structure was formed by pouring grout with different thermal conductivity successively into the same matrix asphalt mixture framework. According to the structural characteristics of grouting compound pavement and the principle of gradient thermal conductivity, the heat in the pavement could be quickly transferred down to the subgrade. The heat transfer performance and cooling effect of GC-DHIS were studied by finite element simulation, and the simulation results were verified by laboratory irradiation experiment. The results showed that the heat exchange between the designed structure and the atmosphere in the endothermic and exothermic periods was 7.10% and 7.98% less than that of the control structure, respectively. Moreover, the effective downward heat transfer rate of pavement throughout the day could be improved, and the maximum temperatures inside the pavement were reduced by 0.9 °C(2 cm), 1.9 °C(5 cm) and 0.8 °C(10 cm). The GC-DHIS with gradient high thermal conductivity grout increased the total downward heat transfer at the depth of 2 cm, 5 cm and 10 cm by 7.0%, 11.9% and 17.4% during the endothermic period. Meanwhile, the surface temperature of this structure in this period showed a slower rising trend. Therefore, it could be concluded that GC-DHIS is a promising pavement structure with the function of actively enhancing heat directional transfer and cooling pavement.