Influence of fly ash and amount of binder material in concrete on chloride diffusion decay coefficient

摘要

In this study, fly ash concrete and ordinary Portland cement concrete with different water binder ratios and various curing ages were used to perform chloride diffusion experiments in accordance with AASHTO T259 (i.e. the ponding test). The hydration reaction of concrete with the binder material increased continuously. Thus, the chloride diffusion coefficient decreased with curing time. The diffusion coefficient of chloride was obtained at different curing ages, 28 days and older. The chloride diffusion decay coefficient and the time-dependent index of the diffusion coefficient for chloride ions were analyzed for different curing ages. The chloride diffusion decay coefficient was found to be a function of the quantity of binder material. Through linear regression, a robust relationship was observed between the chloride diffusion decay coefficient and quantity of binder material. Therefore, the quantity of binder material and the chloride diffusion decay coefficient are accurate predictors of concrete durability.