Research on the influence of concrete damage in wharf structures under fatigue loads on chloride ion diffusion

Abstract

Abstract In the marine environment, harbor structures are prone to fatigue damage due to long-term berthing load, accelerating chloride erosion and leading to steel corrosion, thus significantly reducing the durability and service performance of reinforced concrete structures. To investigate the influence of fatigue damage on chloride ion diffusion, this paper simulated the damage degradation process of structures under fatigue load and chloride ion erosion through experiments. The damage caused by fatigue load was defined by ultrasonic method, and the study investigated the effects of different stress levels and loading cycles on chloride ion transport. The chloride ion diffusion concentration under different damage conditions was predicted by numerical simulation. The results indicate that the fatigue load leads to the increase of load level and the increase of chloride ion content at the same depth. The increase of loading times accelerates the penetration rate, which is positively correlated with the chloride ion diffusivity. The chloride ion diffusion coefficient of concrete exhibits an exponential relationship with fatigue damage levels. The numerical simulation results are consistent with the experimental results, validating the feasibility of establishing a correspondence between thermodynamic diffusion and chloride ion diffusion parameters using the analogy method. This paper provides reliable support for the performance assessment and maintenance of reinforced concrete structures in marine environments.