Chloride Ingress Resistance in Selected Calcined - Clay - Portland Cement Blends

This paper presents the results of an experimental study which was carried out to investigate the chloride ingress resistance of the blend of the calcined clays with Ordinary Portland Cement (OPC); vis a vis commercial OPC and Portland Pozzolana cement (PPC). Clays were sampled from selected regions of Runyenjes ? Kenya. The sampled clays were activated at 800 0C for one hour and blended with OPC at different replacement levels. The blends were subjected to accelerated chloride ingress in accordance with ASTM C1202 with some modifications. The objective of the study was to investigate the durability of blended cement in chloride rich media. Knowledge of the chloride ingress resistivity will lead to research on possible ways of improving the test cement. The study was thus engineered at establishing the robustness of the test cement vis a vis the commercial OPC and PPC. The blended cement and commercial PPC exhibited the highest resistance to chloride ingress in terms of the quantity of electric current allowed in compared to neat OPC in a simulated solution of 3.5 percent sodium chloride solution.