Performance evaluation of sustainable high strength mortars incorporating high volume waste glass as binder

Abstract

This study investigates the performance of sustainable high strength mortars incorporating recycled waste glass as a supplementary cementitious material (SCM) to replace cement from low (10%) to high (60%) replacement ratios, while mortars with conventional mix design are used as reference. The addition of the recycled waste glass significantly improves the slump-flow of fresh mortars in the presence of superplasticizer (SP). The increase of the recycled waste glass dosage contributes to the longer initial and final setting time compared to the plain cement sample. The high volume recycled waste glass containing sample shows an obvious delay of hydration compared with others incorporating the same amount of SP. The high strength series samples containing various contents of recycled waste glass show similar total gel porosity, but a significant increase of gel porosity was observed in the normal strength series samples containing recycled waste glass. From the SEM images, it can be identified that high dosage recycled waste glass-containing high strength mortars show a denser microstructure compared to the plain sample. The higher mesopore volume introduces higher drying shrinkage in sustainable mortars. The mechanical performance tests show that sustainable high strength mortars containing 60% recycled waste glass can achieve a satisfactory strength (99 MPa) compared to the plain cement sample (115 MPa).