DEM analysis of the evolution of reflection cracks in old cement concrete pavement with an ATB layer

Abstract

ABSTRACT The discrete element method (DEM) is one of the most popular methods used to study the performance of pavement materials. However, few studies use the DEM to evaluation the damage performance of asphalt overlays on cement pavements. This paper focuses on the establishment of discrete element models to simulate the reflective crack development of asphalt overlays on cement pavement. Three contact models are selected to realise the pavement structure layer. The results show that under flexural tensile loading and shear loading, the development of reflective cracks can be inhibited with increasing asphalt overlay thickness, while the influence of the interlayer bond strength on the crack development is not obvious. In addition, the flexural tensile load can promote the development of cracks more than shear load. Under the action of thermal fatigue stress, the opening degree of crack displacement increases with the fatigue stress ratio, while the increase in interlayer bond strength can slow down the development and expansion of cracks. Moreover, thermal fatigue stress causes reflective cracks in the overlay to develop earlier and faster.