Simulation of Crack Propagation in Asphalt Concrete Using an Intrinsic Cohesive Zone Model

TLDR

The study investigates fracture behavior in asphalt concrete using an intrinsic cohesive zone model and extends it to simulate mixed‑mode crack propagation in a single‑edge notched beam test. The authors employ an exponential cohesive law tailored to asphalt, implement it in ABAQUS via a user subroutine, calibrate cohesive parameters against single‑edge notched beam tests, and insert cohesive elements to allow arbitrary crack propagation. Simulations show crack trajectories that agree well with experimental observations.

Abstract

This is a practical paper which consists of investigating fracture behavior in asphalt concrete using an intrinsic cohesive zone model (CZM). The separation and traction response along the cohesive zone ahead of a crack tip is governed by an exponential cohesive law specifically tailored to describe cracking in asphalt pavement materials by means of softening associated with the cohesive law. Finite-element implementation of the CZM is accomplished by means of a user subroutine using the user element capability of the ABAQUS software, which is verified by simulation of the double cantilever beam test and by comparison to closed-form solutions. The cohesive parameters of finite material strength and cohesive fracture energy are calibrated in conjunction with the single-edge notched beam [SE(B)] test. The CZM is then extended to simulate mixed-mode crack propagation in the SE(B) test. Cohesive elements are inserted over an area to allow cracks to propagate in any direction. It is shown that the simulated crack trajectory compares favorably with that of experimental results.