Impact of thermal conductivity of base layers and subgrade on temperature distribution in asphalt pavement on highways in Northern delta

Abstract

By using the model to predict the temperature distribution of asphalt pavement on highways in the Northern delta region, which has been built by the author in which the base layer and subgrade are assumed to be an equivalent layer of material with the semi-infinite thickness, known as the base layer, the impact of the thermal conductivity coefficient (TCC) of the foundation layer on the asphalt concrete layer (AC) temperature distribution is included in the study. The results show that the maximum temperature of the AC layer is not affected by the TCC of the base layer. The maximum temperature at the bottom of the AC layer can be reduced by 5.41^oC (11.04%) when the base layer TCC increases from 0.8 to 2.0 W/(m.K). The maximum average temperature of the AC layer decreases when the base layer TCC increases, the degree of reduction is related to the thickness of the AC; when the AC layer is 7 cm thick, the reduction is the largest, reaching 3.59^oC (5.69%). In the case of the base layer, TCC is 2.0 W/(m.K), and the maximum average temperature of the AC layer can be reduced by about 10^oC by using an AC layer with a thickness of 18 cm.