Abstract
Low-temperature degradation affects the bearing capacity of rock-lining constructions surrounding tunnels in chilly regions. In this work, rock-concrete composites with varied interface angles (0°, 30°, 45°, 60°, 90°) were tested for freeze-thaw (F-T) cycles (0, 4, 8, 12, 16) and uniaxial compressive strength. The impact of F-T cycles and interface angles on the strength degradation of composite specimens was quantitatively evaluated. The microscopic degradation mechanisms induced by F-T cycling were analyzed using scanning electron microscopy. According to the experimental findings, the F-T mass loss rate of the specimens followed a power-law distribution. Under the influence of F-T cycles, the peak strength loss rate reached a maximum of 40%. Under the influence of the interface angle, the elastic modulus of specimens subjected to different F-T cycles displays varying trends. Finally, an innovative damage constitutive model was developed that couples the evolution of F-T damage with the effects of interface angles. The model is applicable for predicting the impact of F-T cycling on the durability of rock-concrete structures, which provides effective support for the long-term performance evaluation of the structure.