Three-Dimensional Finite Element Analysis of Bottom-Up Crack in Asphalt Pavement under Traffic Loading

This paper investigates the behaviour of a bottom-up crack within the asphalt layers of a pavement structure under traffic loading. The pavement is a multilayer structure comprising two asphalt layers on top, with the crack being a longitudinal crack that originates from the bottom of the asphalt layers and advances upward under one wheel of a pair of wheels. The analysis is conducted using three-dimensional finite element modelling techniques with Abaqus software, and the stress intensity factors are calculated for different crack lengths, layer thicknesses and load positions. The results show that mode I does not contribute to crack propagation and that only mode II contributes when the crack is in the first asphalt layer, while the contribution of mode III is negligible. Once the crack reaches the interface between the two asphalt layers, it deviates and propagates along the interface rather than penetrating into the upper layer, resulting in delamination of the pavement between the two layers, where Modes II and III contribute to the crack propagation. The results further indicate that the variation of layer thicknesses has a notable impact on the stress intensity factors KI and KII when the crack is located in the first layer.