Simulation of Corrosion-Induced Cracking of Reinforced Concrete Based on Fracture Phase Field Method

Accurate simulation of the cracking process caused by rust expansion of reinforced concrete (RC) structures plays an intuitive role in revealing the corrosion -induced failure mechanism. Considering the quasi -brittle fracture of concrete, the fracture phase field driven by the compressive -shear term is constructed and added to the traditional brittle fracture phase field model. The rationality of the proposed model is verified by a mixed fracture example under a shear displacement load. Then, the extended fracture phase model is applied to simulate the corrosion -induced cracking process of RC. The cracking patterns caused by non -uniform corrosion expansion are discussed for RC specimens with homogeneous macroscopically or heterogeneous with different polygonal aggregate distributions at the mesoscopic scale. Then, the effects of the protective layer on the crack propagation trajectory and cracking resistance are investigated, illustrating that the cracking angle and cracking resistance increase with the increase of the protective layer thickness, consistent with the experimental observation. Finally, the corrosion -induced cracking process of concrete specimens with large and small spacing rebars is simulated, and the interaction of multiple corrosion cracking is easily influenced by the reinforcement spacing, which increases with the decrease of the steel bar interval. These conclusions play an important role in the design of engineering anti -corrosion measures. The fracture phase field model can provide strong support for the life assessment of RC structures.