Acid resistance of alkali-activated composites containing waste glass as fine aggregate

Abstract

This study examined the efficacy of waste glass cullet (WGC) as a substitute for natural fine aggregate in alkali-activated composites when exposed to sulfuric acid and hydrochloric acid solutions for 1 year. The physical appearance, surface alkalinity, mass, mechanical strength and microstructure of hardened samples before and after immersion in acid solutions were investigated. The findings this work indicated that physical, mechanical and microstructural damage of the specimens due to acid attack increased with an increase in the percentage of WGC. This was attributed to the smooth surface texture and angularity of the WGC, which affected the bond with the damaged paste matrix at the interfacial transition zone and increased the porosity. However, the acid resistance of the mortars containing up to 50% WGC was found to be satisfactory when compared with the mortar without WGC. Therefore, the use of WGC as a partial replacement (up to 50%) for natural sand is feasible for alkali-activated systems under acid exposure.