Temperature response of asphalt pavement to low temperatures and large temperature differences

Abstract

Temperature responses of asphalt pavements are significant, because of their potential influence on pavement structure design and distress prevention, particularly in areas that experience large temperature difference. In this study, a 3D finite element model is developed based on transient heat transfer. The aim is to analyse the temperature responses of the Karamay–Altay Highway in northern Xinjiang, which tends to experience large temperature differences and low temperatures. First, the climatic characteristics and pavement distresses in northern Xinjiang were investigated, and the condition defining a large temperature difference was established. Then, to guide the design of the Karamay–Altay Highway pavement structure, the temperature fields of seven pavement structures were determined. The temperature field of the Str-m structure in the Karamay–Altay area was compared to that in Xi’an. In the Karamay–Altay area, it was observed that Str-4 exhibited the minimum temperature variation at the bottom of the asphalt course and base course. It was clear that the degree of downward temperature transfer was closely related to the structure combination type. The results also suggested that a thicker asphalt layer would effectively reduce temperature effects and diminish distresses resulting from temperature. By comparing of the temperature fields of the Str-m structure in the Karamay–Altay area and in Xi’an, it was observed that pavement temperature fields changed drastically in the case study area, and hence revealed that severe pavement cracks in this area were closely related to abrupt temperature changes, low temperatures and large temperature differences. Hence, it was concluded that in northern Xinjiang, pavement designers should consider the large temperature difference condition very carefully.