Effect of mineral admixtures on time-dependence of concrete exposed to chloride diffusion

The chloride diffusion behavior of the concrete mixed by mineral admixtures and exposed under the condition of high concentration solution is investigated, and the influence of exposing time on the concrete apparent chloride diffusion coefficient is probed by the natural diffusion method. Results show that the concrete apparent chloride diffusion coefficients reduce with the increase of exposing-time and the time-dependence is related to the proportion of mineral admixtures. When the proportions of fly ash and silicon fume reach 30% and 15%, respectively, the apparent chloride diffusion coefficients of fly ash and silicon fume concrete reduce the most quickly with time. Therefore, the long-term ability against chloride corrosion of fly ash concrete or silicon fume concrete is better than that of the ordinary Portland cement concrete.