Modeling Chloride Transport in Concrete a Pore and Chloride Binding

Abstract

The present study concerns modeling of chloride diffusion in concrete by reflecting the pore size distribution and binding of chloride in the cement matrix. As factors that influence the chloride diffusion, water-cement ratio (w/c) and replacement ratio for blended cement concrete were taken. As a result, it was found that an increase in w/c and a decrease in the replacement ratio resulted in an increase in the fraction of effective pore volume for chloride transport, while chloride binding capacity decreases with w/c and increases with the replacement ratio. Also, the higher chloride binding capacity could cause an increase in total chlorides at concrete surface, which could enhance the concentration buildup rate at smaller cover depth in the long term. However; after reaching the limited chloride binding capacity, the diffusion coefficient decreased with time, implying that a reduction of the diffusion rate could be attributed to the chloride binding.