Temperature Changes of Interlaminar Bonding Layer in Different Seasons and Effects on Mechanical Properties of Asphalt Pavement

In this study, the discrete-element model (DEM) of asphalt pavement is established to discuss the effects of temperature changes of interlaminar bonding layer on mechanical responses of asphalt pavement in different seasons. Calculated and test results indicate that the temperature within the depth range of 0–5 cm in asphalt pavement is obviously affected by ambient temperature. The heat is accumulated within the pavement depth range of 2–5 cm, greatly affecting the interlaminar bonding state. In addition, lower temperature in winter increases the continuity of asphalt pavement layers, reducing the compressive stress in upper layer. In addition, higher temperature in summer weakens the interlaminar bond, increasing the horizontal tensile stress in upper layer and at the interlaminar interface. Further, lower interlaminar bonding strength increases the maximum shear stress at the interlaminar interfaces between asphalt pavement layers, as well as at the interface between asphalt mortar and aggregate. As the pavement depth is increased, the horizontal shear stress is increased. Finally, the high temperature increases the tensile strain near the bottom of upper layer. The displacement directions of more aggregate particles move vertically downward at low temperature, but move to two lateral sides at high temperature.