Bond Property Test and Numerical Simulation of the Interface Layer between Asphalt Plug Joint and Pavement

The development and application of asphalt plug joints have gained popularity due to their unique advantages, such as driving comfort, shock absorption, noise reduction, and convenient management and maintenance. However, these expansion joints are susceptible to damage at the interface due to long-term exposure to traffic loads and environmental factors. Specifically, the interface bond damage between the asphalt plug joint and the pavement directly impacts the service performance and durability of bridge expansion joints. To address these issues effectively, this paper proposes an interface binder with improved bonding performance based on pull-off and oblique shear tests, which is used to enhance the interface cracking resistance of the asphalt plug joint structure. The research focused on the interface layer between Marshall and concrete specimens. A finite-element model of the pull-off specimen, which includes a bilinear cohesive element, was established to simulate the cohesive damage process between the interface layers. The constitutive relationship of the bilinear cohesive element utilizes the bond-slip constitutive curve obtained from the tests. It combines the maximum nominal stress (Maxs criterion) and the linear softening method of energy to simulate the fracture process of the interface layer. The simulation results were compared with the experimental data. Additionally, a parameter design analysis was conducted to study the influence of individual parameter variables on the interface damage behavior. The analysis provided robust data support for simulating the interfacial crack resistance. The results indicate that the simulation analysis aligned well with the experimental data, and the bilinear cohesive model can effectively capture the nonlinear behavior of the interface layer bond-slip. The loading method and the type of binder were found to have a significant impact on the interface bond fracture energy. The results demonstrate the effectiveness of the proposed approach in capturing the nonlinear behavior of the interface layer and provide valuable insights into the influence of different parameters on interface damage behavior.