AN EFFECTIVE DIFFUSIVITY FOR SULFATE TRANSPORT INTO CONCRETE

The effective non-steady state diffusivity of sulfate ingress from a m ixed sulfate-chloride solution into Type 50 cement concrete was determ ined from concentration profiles at various times up to five years. Fu rthermore, the influence of CO2 saturation on the effective diffusivit y was determined. The time dependence of the effective non-steady sulf ate diffusivities were, log (D-effective (sulfate)) = -6.6543 -0.7626 log(t) and, log (D-effective (CO2)(sulfate)) = -6.2873 - 0.8559 log(t) where D-effective (sulfate) represents the effective sulfate diffusiv ity, D-effective (CO2)(sulfate) represents the effective sulfate diffu sivity of the solution saturated with respect to CO2, and t represents the time (months).