Effect of waste stream materials on properties of cement mortars when used as supplementary binding materials

Abstract

The present study focuses on the effect of waste stream materials on various properties of cement mortar when the waste materials are used as supplementary binding/cementitious materials (SCMs) for partial replacement of binding material. The effect and properties of various types of SCMs that are commonly used in mortar preparation replacing a part of cement (%) like limestone dust (LS), cement kiln dust (CKD), ground granulated blast furnace slag (GGBS), dolomitic limestone (DLS), ladle furnace slag (LDF), silica fume (SF), ceramic wastes (CW), fly ash (FA), pulverized fuel ash (PFA), waste glass sludge (WGS), etc. are studied and presented. Effects and characteristics of various combinations of different supplementary binding materials like the combination of FA with LS, an amalgamation of FA with DLS, the compatibility of FA with WGS, the mixture of GGBS with PFA, blending of GGBS with CKD, etc. are studied and reported. The elemental composition, pore size distribution system and microstructural composition were studied through X-ray diffraction (XRD), mercury intrusion porosimetry (MIP) and scanning electron microscope (SEM) and discussed. The results of the study revealed that a combination of GGBS and PFA yields better results than the reference mixes made of cement and other blended mixes made of SCMs. The performance of CW and WGS is found good at the later age. The performance of fly ash on mortar properties depended on the dosage and fineness of fly ash. Apart from their better solo performance, a combination of limestone dust and silica fume not only enhances the strength but also the sulphate resistance of mortar. The study revealed that the use of SCMs in mortar contributes to a reduction in cement production and carbon emission.