Influence of tack coat on reflective cracking propagation in semi-rigid base asphalt pavement

Abstract

Asphalt tack coat, which is usually used to ensure a bond between asphalt pavement layers, has a significant effect on mechanics response in asphalt pavement during traffic loading and temperature loading. In this paper, the tack coat is applied between asphalt overlay and semi-rigid base to investigate its influence on reflective crack in asphalt pavement. Cohesive zone model (CZM) in contact property is employed to simulate tack coat. Moreover, extended finite element method (XFEM) is utilized to analyze the reflective cracking propagation. In addition, the combined loads of temperature and moving traffic are applied on the asphalt pavement. The mechanical response, crack temperature and reflective cracking propagation are investigated in semi-rigid base asphalt pavement. Results indicate that maximal tensile stress at crack tip increases with the increase of tack coat modulus while crack propagates. However, the maximal tensile stress at pavement surface decreases with the increase of tack coat modulus while crack propagates. A decrease in tack coat modulus results in a gradual increase in temperature differences of crack initiation and crack completion. Hence, decrease of tack coat modulus between asphalt overlay and semi-rigid base can improve resistance of reflective crack in asphalt pavement.