Numerical Simulation of Transport Process of Chloride in Concrete under the Action of Sulfate

The diffusion law of Cl- in common concrete containing SO42- was studied. 0.1 mol/L, 0.3 mol/L and 1 mol/L sodium sulfate were added, respectively, in 1 mol/L sodium chloride as composite solution, and clean water was taken as contrast. According to the experimental parameters and the Fick diffusion law, the diffusion coefficient of chloride ion in concrete was analyzed and numerically calculated using ANSYS software. The results showed that, in the experimental range, the equivalent of chloride ion diffusion coefficient exponentially decreased with time; when the sulfate concentration in solution increased from 0 to 0.3 mol/L, the chloride ion diffusion increased gradually, when the sulfate concentration was 1 mol/L, the chloride ion diffusion decreased. The expression showing the relationship between chloride ion equivalent diffusion coefficient, diffusion time and boundary concentration of sulfate ion was established after the experimental results data were fitted. The expression can be used to predict the concentration of the internal concrete chloride ion in this type of environment.