Time Dependent Chloride Diffusion Coefficient in Concrete in Cold Regions

Chloride and freeze-thaw cycles are two main factors which cause deterioration of reinforced concrete (RC) structure in the cold regions. In this paper, the process of chloride ingress into concrete exposed to freeze-thaw cycles is experimentally researched. From the experimental results, it appears that freeze-thaw cycles make the effective diffusion coefficient become bigger. Based on the experimental data, the concept of developing coefficient was defined to obtain the evolution equation of effective diffusion coefficient. Together with considering the effect of aging of concrete on effective diffusion coefficient, the time dependent diffusion coefficient of concrete in cold regions was obtained.