Use of pumice fine aggregate as an alternative to standard sand in production of lightweight cement mortar

Abstract

The purpose of this study is to evaluate the possibility of using granulated pumice as an alternative to fine aggregate in production of lightweight cement mortar. The cement/pumice fine aggregate ratio is 1:3 for pumice aggregate mortar. The water content is determined by flow table test. Compressive and flexural strength, freeze-thaw resistance, sulfate resistance, water absorption and dry unit weight of the mortars are determined. Mortar using 100% pumice as fine aggregate developed strength in excess 12 MPa and had an oven dry density of 1140-1146 kg/m(3) would satisfy the requirements for lightweight mortar and it can be used as in cast in place walls, load bearing and non-load bearing structures. Pumice aggregate mortar is about 50% lighter than Portland cement control mortar due to the replacement of comparatively heavier standard sand by lighter pumice aggregate. The pumice aggregate mortar exhibits a higher frost resistance due to the existence of voids in pumice aggregate. Pumice aggregate mortar showed better performance showing higher residual strength at high temperatures compared Portland cement mortar. The residual compressive strength reduction of pumice aggregate mortar is higher than that of Portland cement mortar exposed to freeze-thaw cycles. The use of pumice aggregate as sand provides the resistance to sulfate attack.