An exposure experiment of concrete was carried out in marine atmospheric environment,the total chloride ion and free chloride ion contents of concrete were determined.The characteristics of free chloride ion and bound chloride ion contents changing along with time were investigated in the process of chloride ion diffusion.Meanwhile,chloride ion binding capacity was calculated at each different exposure time and diffusion depth, and the effect of exposure time and diffusion depth on chloride ion binding capacity of concrete were discussed by regression analysis.The results showed that the chloride ion binding capacity is the power function of exposure time and meets cubic polynomial function with diffusion depth.The fitted values agree well with the measured values and it indicate that the functions are efficient.
