Role of calcium on chloride binding in hydrated Portland cement–metakaolin–limestone blends

Chloride binding is investigated for Portland cement–metakaolin–limestone pastes exposed to CaCl2 and NaCl solutions. The phase assemblages and the amount of Friedel's salt are evaluated using TGA, XRD and thermodynamic modeling. A larger amount of Friedel's salt is observed in the metakaolin blends compared to the pure Portland cement. A higher total chloride binding is observed for the pastes exposed to the CaCl2 solution relative to those in...