Development of Alkali-activated Cementitious Material using Copper Slag

Abstract

The paper presents results of an investigation conducted to study the feasibility of use of Copper Slag (CS) as aluminosilicate material for developing Alkali-activated Cementitious Material (ACM). The effect of addition of mineral admixtures such as Fly Ash (FA) and Metakaolin (MK) on the performance of alkali-activated CS was also investigated. In addition to a control mix which was prepared using 100% CS; two other mixes were also prepared by replacing CS with 30% FA and 30% MK respectively. These mixes were activated using alkali content of 5% and 7% by weight of binder. Sodium hydroxide and sodium silicate were used as alkali-activators. Compressive strength tests were performed on alkali-activated cement mixes at different curing ages. The pore-size distribution, mineralogy and microstructure of selected alkali-activated cement mixes were determined using Mercury Intrusion Porosimetry (MIP), X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) with Energy Dispersive X-ray Spectroscopy (EDS). Test results indicate that CS has great potential as aluminosilicate material for developing ACM. Further, the addition of mineral admixtures in alkali-activated CS cement improves its performance; however, the addition of MK was found to be more effective than FA in terms of compressive strength and microstructure development.