Recycled waste medical glass as a fine aggregate replacement in low environmental impact concrete: Effects on long-term strength and durability performance

Abstract

Recycling and reusing solid wastes as construction materials is an issue that has received much attention from research scholars around the world in recent years. This research was developed to investigate the long-term mechanical and durable characteristics of concrete that was produced utilizing recycled waste medical glass aggregate (WGA) as a partial to full replacement of natural crushed sand (NCS). The mechanical properties of the different concrete mixtures were evaluated using compression and ultrasonic pulse velocity tests, and durability was assessed using water absorption, rapid chloride permeability, and sulfate resistance tests. The effects on the environmental impact of concrete production using WGA as an NCS replacement in terms of energy consumption and CO2 emissions were also assessed. The experimental results indicate that both the mechanical properties and durability of the concrete mixtures were improved as the level of WGA replacement increased from 0 to 60%, while the 80% and 100% WGA mixtures were inferior in terms of mechanical and durability to the standard concrete mixture (i.e., 0% WGA). The 60% WGA mixture exhibited the highest performance in terms of both mechanical properties and durability. This assessment was confirmed by the scanning electron microscope results, which indicated the 60% WGA mixture had the densest structure with more calcium silicate hydrate. Finally, the environmental assessment result supports using WGA as an environmental-friendly construction and building material in concrete for sustainable development.