To determine the micro-cracking mechanism in epoxy asphalt concrete (EAC) so as to guide the crack rehabilitation strategy, the process of cracking initiation and propagation in the EAC were measured using a digital image correlation approach, and was simulated based on an extended finite element method. Firstly, the three-point bending test was conducted during which cracking initiation and propagation in EAC were measured and fracture parameters of mastic cement and aggregate were determined. Then numerical simulation was performed based on an EAC microstructure model. Simulation results of cracking match well with the micro-crack initiation and propagation process in EAC measured in the laboratory at a low temperature. The specimen fracture process and the cracking propagating route are discussed based on the analysis results.

Cracking in epoxy asphalt concrete (EAC) used for a steel bridge wearing course has always been a major cause of structural and functional deterioration of this material, particularly in cold climate. Therefore, it is important to understand the complex fracture behavior of this heterogeneous mixture, which is composed of irregularly shaped and randomly distributed aggregates surrounded by asphalt mastics. A three-dimensional (3D) fracture model independent of laboratory, based on the discrete element method (DEM), is reconstructed using a randomly generating algorithm to investigate the fracture behavior. A bilinear cohesive-softening model is implemented into the DEM framework to simulate the crack initiation and propagation in EAC. Several experimental tests are performed to obtain input parameters of materials for numerical models. The simulation results of a single-edge notched beam test agree well with experimental results and accurately capture the stress distribution and development of fracture zone. The modeling technique herein provides insight into the progressive cracking process; 3D visualization of crack trajectories also demonstrates the influence of heterogeneity on crack path. The 3D user-defined microstructural DEM fracture model is capable of giving a realistic cracking process of quasi-brittle materials such as EAC and can help us better understand various fracture mechanisms through numerical simulations.

In order to extend the service life of the steel bridge deck pavement, a long‐life steel bridge deck pavement (LLSBDP) was put forward referring to the concept of long‐life asphalt pavement. First, the requirements of the LLSBDP were given, based on which, an LLSBDP structure “EAC + SMA” was proposed. Second, a numerical analysis was performed to evaluate the stress status of the “EAC + SMA” structure. Third, an experimental study was conducted to assess the performance of the pavement material and the pavement structure. Meanwhile, for comparison, the performances of traditional steel bridge deck pavement structure “EAC + EAC” were also studied in the numerical and experimental program. The results showed that, with periodical rehabilitation or reconstruction of the SMA surface layer, the EAC base layer can last for a long life without structural distresses. The proposed structure can meet the requirements of LLSBDP and can be used to extend the service life of the steel bridge deck pavement.