Alkali-activated waste glass as an alternative cement for preparation of potential low-carbon concrete

The environment is currently confronted with challenges arising from the substantial accumulation of challenging-to-recycle waste glass. To address this issue, the utilization of alkali-activated waste glass (AAWG) emerges as a promising solution for generating potential low-carbon materials. AAWG, serving as a novel binder, is characterized by a lack of Al/Ca, diverging from both geopolymer and calcium silicate hydrate gels. Consequently, variations in gel properties necessitate corresponding adjustments in AAWG preparation methods. However, to date, there has been limited comprehensive exploration by researchers into the effects of curing conditions (humidity, temperature, and duration) on the compressive strengths of AAWG. The interaction among these factors in influencing AAWG compressive strengths remains unclear. Furthermore, the feasibility of employing AAWG as a standalone binder in concrete, along with the performance of the interfacial transition zone around the aggregates, remains uncertain. Considering these unresolved issues, this study investigates the impact of curing conditions (humidity, temperature, and time) on AAWG compressive strengths. Concrete incorporating AAWG as the binder, granite as coarse aggregates, quartz sand as fine aggregates, and silica sand/ flour as inert fillers exhibited compressive strengths surpassing 75 MPa. This research contributes to advancing the upcycling of waste glass to produce high-strength concrete.