Experimental Study on Regularity of Sulfate-ion Diffusion and Distribution in Concrete Attacked by Sulfate

The regularity of sulfate-ion distribution in concrete immersed long time in different concentration of sodium sulfate solution was analyzed by the chemical method,the micro-mechanism of sulfate corrosion and deterioration regularity of concrete strength was verified by the TG-DSC method.It is proved that the sulfate-ion concentration on concrete surface increase with the increase of the corrosion ages,the sulfate-ion diffusion coefficient in concrete decreases with the increase of the corrosion ages.On the basis of Fick' Law,the model is suggested for forecasting the sulfate-ion concentration in concrete immersed in sodium sulfate solution,the formulas are proposed for calculating the sulfate-ion concentration on concrete surface and the sulfate-ion diffusion coefficient in concrete.