Waste glass sludge as a partial cement replacement in mortar

This paper presents the results of a study conducted to evaluate the possibility of utilizing the waste glass sludge (WGS) from the cutting and polishing process of glass plates, as a partial replacement of cement. A total of seven mortar mix proportions were prepared, by replacing ordinary Portland cement with WGS and/or fly ash (FA). The influences of WGS and FA on the compressive strength of mortars and ASR expansion of mortars were investigated. In addition, X-ray diffraction analysis was performed, to evaluate the pozzolanic activity. The results show that the incorporation of the WGS yields mortars with improved strengths at the later age (28 days), in comparison with that of a control mortar (ordinary Portland cement only); while the WGS caused a lower early strength than that of control, but higher than that of mortars containing FA. The ASR expansion of the mortars can be reduced by incorporating WGS as effectively as by fly ash. It is found that the consumption rate of calcium hydroxide for the paste with the WGS was faster than that of paste with FA, up to 28 days. These results indicate that the WGS has a higher reactivity than FA; and therefore, the WGS can be used as a pozzolanic admixture in cement composites.