Investigation of asphalt pavement crack propagation based on micromechanical finite element: A case study

Abstract

Cracking is a prevalent issue in expressway pavements in Shanxi Province, exhibiting various types. Based on field investigations, the primary types of asphalt pavement cracks observed in Shanxi expressways can be categorized as top-down crack (TDC, surface crack) and reflection crack (bottom-top crack). These two types differ significantly in terms of cracking mechanisms, development modes, treatment methods, and impact severity. This paper aims to simulate the initiation and propagation processes of top-down cracks and reflection cracks using the finite element method, aiming to provide a basis for distinguishing between the two. In this paper, a microstructure numerical model of a three-phase asphalt concrete pavement is established. Finite element software is utilized to simulate the initiation and propagation of top-down cracks and reflection cracks on asphalt pavement, while investigating the influence of various factors on crack propagation. The findings demonstrate that top-down cracks exhibit multi-point cracking on the pavement surface, resulting in a tortuous and discontinuous development process. Conversely, reflection cracks display significant stress concentration at the crack tip, leading to propagation even under loads significantly lower than the material's tensile strength, following a single propagation path. Aggregate distribution form, preset crack length, tensile strength of ITZ, and load distribution form do not have a significant effect on the primary cracking mode. However, they do influence the crack initiation point, cracking load, and propagation path to some extent.

Keywords

• Asphalt pavement
• Top-down crack
• Reflection crack
• ITZ