Effect of Waste Ceramic Polishing Powder on the Properties of Cement Mortars

An innovative approach of reusing waste ceramic polishing powder generated in ceramic industries to develop admixture in cement was studied. Effects of waste polishing powder (PP) on compressive strength, pore structure, dry shrinkage ratio, heat of hydration and microstructures were studied comparing to fly ash (FA). Results show that waste polishing powder has high of pozzolanic activity than fly ash does. The cement mortar strength active index of PP is up to 83.6% and that of FA in experimental is only 72.3%. The addition of PP reduces the heat of hydration of cement and accelerates the early hydration of cement pastes. But the dry shrinkage of mortars increased obviously as the admixture of PP is increased, however, mixing compound PP and FA in mortars conduces to decrease the dry shrinkage of mortar. Microstructure analysis and mercury intrusion porosimetry of mortars further indicated that larger amount of hydration product is formed in mortars added polishing powder, which results in the low average pore diameter and the dense cement pastes.