Adding ceramic polishing waste as paste substitute to improve sulphate and shrinkage resistances of mortar

Abstract

Ceramic polishing waste (CPW) is a solid waste generated during the polishing process of ceramic tiles. Its disposal as waste has been causing lots of environmental problems. In this study, the authors made an attempt to reutilize the CPW in mortar as paste substitute (substituting part of the paste without changing the paste compositions) and a series of mortar mixes containing various CPW, cement and water contents were made for conducting the sulphate attack test and drying shrinkage test. The test results showed that as paste substitute, the CPW added can significantly enhance the compressive strength, sulphate resistance and shrinkage resistance of mortar, and at same time substantially cut down the cement demand to lower the carbon footprint. Regression analysis also revealed that for strength enhancement, the cementing efficiency factor of the CPW was as high as 1.10, whereas for sulphate resistance enhancement, the cementing efficiency factor was about 0.69.