Electrochemical chloride extraction effect on blended cements

Abstract

Use of high magnitude current for electrochemical chloride extraction (ECE) has led many researchers to look at the side effects on ordinary Portland cement (OPC) but not blended cements. To simulate the effect of applying electrochemical chloride extraction on blended cements experimentally, 100% OPC, 70% OPC + 30% pulverised fuel ash and 60% OPC + 40% ground granulated blast-furnace slag were prepared and subjected to electrolysis between embedded steel cathodes and external anodes of activated titanium mesh. The cathodic current density applied was 5 A/m2 over a treatment period of 12 weeks. The effect of ECE on the physical and microstructural properties of the specimens was studied using microhardness and mercury intrusion porosimetry techniques. Eventually, removal of chloride ions was noted to be more effective in OPC in comparison with blended cements. In addition, although a slight increase in the total porosity was observed near the steel cathode in the OPC matrix, the reverse was, however, the case with the blended cements.