Evaluating toughened glass aggregate mortar for strength and alkali-silica reaction durability: from waste to worth

This study explores the use of toughened glass waste aggregates (TGWA) as a partial replacement for M-sand in cement mortars, focusing on evaluating mechanical and durability properties, as well as mitigating alkali-silica reaction (ASR) expansion. Mortar mixes were prepared with TGWA replacing M-sand at levels of 20, 40, 60, 80 and 100%. Tests, such as compressive strength, split tensile strength, flexural strength, water absorption and rapid chloride ion penetration were conducted. The research also assessed the effects of particle size and pre-existing cracks influence the TGWA's behaviour under ASR expansion, using the accelerated mortar bar test (AMBT) and microstructural analysis. Results show that TGWA20 mix exhibits enhanced compressive strength by 16.1%, split tensile strength by 10.55% and flexural strength by 8% over conventional mortar, while the TGWA100 mix demonstrated superior durability, with lower water absorption and reduced chloride ion penetration. Additionally, ASR testing revealed that TGWA100 reduced expansion by 32% compared to the control. Overall, the findings confirm that TGWA can effectively replace M-sand in mortar offering improved performance as further validated by FESEM microstructural analysis. These results indicate that TWG aggregates meet the required quality standards, making them a viable option for future construction applications.