Experiment on Sulfate-ion Distribution of Concrete Long-term Steeped in Sulfate Solution

Corresponding to the concrete attacked by long-term steeping sulfate solution in conditions and action grades of moderate,serious and very serious,the sulfate solutions were made with concentration of sulfate-ion of 800 mg/L,6 000 mg/L and 50 000 mg/L respectively.When the cubic concrete specimens with strength grade C40 were soaked in different ages,the samples were made by drilling,cutting into slices and grinding into powder,and tested by the chemical analysis method.The diffusion and transportation regularity of sulfate-ion in concrete was studied.It can be concluded that there are complex relationships between the diffusion of sulfate-ion into concrete with the concentration of corrosion solution and corrosion ages.In the earlier stage,the diffusion speed of sulfate-ion and the corrosion depth are larger.But with the increase of corrosion ages,the sulfate-ions are mainly concentrated in the shallow of concrete,and the content of sulfate-ions are obviously increased with the increase of the concentration of corrosion solution.