Viscoelastic-Thermodynamic Model and Crack Propagation in Asphalt Concrete Pavement

Abstract

Asphalt concrete pavement has a wide range of applications in the construction of high-grade highways. Asphalt concrete pavement has elastic properties, and its viscoelasticity and viscoplasticity are obviously affected by temperature. To determine whether a structure can continue to be used safely, it is most important to determine whether microscopic or macroscopic cracks present in the structure continue to propagate and cause structural failure. The purpose of this study was to study the effects of different ambient temperatures and mobile vehicles on the stress around the crack tip and the propagation path of different types of asphalt pavements. Based on the theory of fracture mechanics and viscoelasticity, this work studies the problem of crack propagation from a macroscopic perspective. It proposes to use the finite element method to analyze the crack problem in the pavement structure. With the help of ABAQUS software, a curved beam model with cracks was established for calculation, and moving loads and ambient temperature fields were added for analysis. The experimental results in this study show that with the decrease in the ambient temperature, the stress at the crack tip increases continuously. As the analysis time increases, the stress also increases. When the crack is smaller, the stress value at the tip is larger. When a = 15 mm, the stress value at the crack tip is the largest. However, when a = 20 mm and a = 25 mm, the stress at the crack tip is significantly reduced. It shows that the crack is easier to crack when the crack value is smaller. After the crack has grown to a certain length, the growth rate will slow down.