Test and Evaluation for Effects of Freeze-Thaw Cycles on Fracture Performance of Epoxy Asphalt Concrete Composite Structure

The fracture performance of epoxy asphalt concrete (EAC) pavement on the top of orthotropic steel deck bridges is influenced by repeating freeze-thaw (FT) cycles in seasonally frozen areas. In this article, the effects of FT cycles on the fracture behavior of EAC composite structures are investigated considering the climatic conditions of Beijing in China. EAC beams were exposed to different FT cycles for conditioning, then the flexural modulus was determined by three-point bending tests. Additionally, the plane-strain fracture toughness and the mechanical response of the EAC composite beams were investigated through numerical simulation. The results show that the flexural modulus of EAC decreases with FT conditioning. Specifically, the flexural modulus decreases by 60.3 % after 30 FT cycles. Nevertheless, the plane-strain fracture toughness and the maximum transverse tensile stress of the EAC composite beams decrease in the first 15 FT cycles and increases for the rest of the FT cycles, while the maximum transverse tensile strain decreases in the first 10 FT cycles and increases for the rest of the FT cycles. The maximum interlayer shear stress between EAC layers is smaller than that between the lower EAC layer and the steel deck. No significant damage is observed in the bonding layer exposed to FT conditioning.