Chloride profiles in surface-treated mortar specimens

Abstract

Mortar specimens coated with six different surface treatments were immersed in 1 M NaCl solution for almost a year and then chloride profiles were measured. The interfacial chloride content C i between the surface treatment layer and the substrate and the pseudo diffusion coefficient D ps were calculated by fitting the error function solution of Fick’s 2nd law to the profiles in the substrate. All of the surface treatments reduced C i to below the surface chloride content of the untreated control specimen, indicating that chloride diffusion into the substrate was restricted by the surface treatments. The effect of surface treatments on D ps varied. The experimental data are compared with a numerical model of chloride diffusion and discrepancies are discussed in terms of factors not included in the model.