Diffusivity of Binary and Ternary Concrete Mixture Blends

Using supplementary cementitious materials (SCMs) to decrease concrete diffusivity, which slow the ingress of chlorides into concrete that results in reinforcement corrosion, is one of the most economical ways to increase concrete service life. To show the effect of ternary SCM blends on concrete diffusivity, bulk chloride diffusion testing was performed on 12 SCM concrete mixtures cured in air, with a curing compound, or under continuous wet curing for 28 days, 91 days, and 180 days. The ternary mixtures interacted synergistically, reducing diffusivity at greater rates than binary SCM mixtures. The chloride diffusion coefficients of specimens cured outdoors were six times greater than for wet-cured specimens and the application of curing compound did not result in significant diffusivity reductions. Experimental data were compared to service-life-modeling software predictions for the experimental mixtures and showed that current software service-life predictions correspond to worst-case curing conditions.