An effective diffusivity for sulfate transport into concrete

The effective non-steady state diffusivity of sulfate ingress from a mixed sulfate-chloride solution into Type 50 cement concrete was determined from concentration profiles at various times up to five years. Furthermore, the influence of CO{sub 2} saturation on the effective diffusivity was determined. The time dependence of the effective non-steady sulfate diffusivities were, log (D{sub eff sul}) = {minus}6.6543--0.7626 log (t) and, log (D{sub eff sul}{sup CO{sub 2}}) = {minus}6.2873--0.8559 log (t) where D{sub eff sul} represents the effective sulfate diffusivity, D{sub eff sul}{sup CO{sub 2}} represents the effective sulfate diffusivity of the solution saturated with respect to CO{sub 2}, and t represents the time (months).