Study On The Hydration Behavior Of Portland Cement Partially Replaced With Mineral Additives Via An Electrochemical Technique

Abstract

In this work, the effects of mineral admixtures, corn cob ash (CCA) and waste plastic fiber (WPF) fillers, on mechanical properties and hydration of Portland cement (PC) were investigated. The partial replacement of both WPF and CCA in PC accelerates the setting process as compared to control PC sample without additives. The addition of WPF decreased the compressive strength of PC and the strength of 42.1 MPa has been obtained in 4-weeks of curing time. CCA addition rises the strength and maximum value of 74 MPa has been found. The electrochemical results indicate that the values of charge-transfer resistance in the equivalent circuit model for PC increase with increasing hydration period. CCA replacement can affect the resistance value in the equivalent circuit. In the 4-weeks hydration time, CCA additives can decrease the resistance value and hydration degree of PC paste. The surface morphology of samples indicated that modified CCA-concrete had lower hydration products than the PC concrete, which was compatible with electrochemical results.