An overview on the reuse of waste glasses in alkali-activated materials

Alkali-activated materials (AAMs) have been attracting much attention worldwide owing to their excellent performances such as strong resistance to chemical corrosion and thermal properties, and the valorization of industrial waste materials. The reuse of waste glasses as aggregates, precursors and activators in the preparation of AAMs seems a feasible path of efficient utilization of solid waste and reducing the cost of AAMs. This paper comprehensively reviews researches on waste glasses reused in AAMs from three aspects is presented: reuse of waste glasses as aggregates, precursors and activators. The incorporation of waste glasses as fine aggregates can enhance the workability, thermal conductivity and capacity against sulfate attack of AAMs. The reuse of glass powders as precursors can generate acceptable strengths. Three methods, i.e. fusion, hydrothermal process and thermochemical process are applied to use waste glasses to manufacture alternative activators. However, the related research on the employment of waste glasses in AAMs is limited. For instance, the absence of assessment criteria on the reactivity of waste glasses, the potential ASR expansion of glass aggregates. More energy-efficient methods of synthesizing activators with waste glasses and investigation into the durability of AAMs with waste glasses are required in the future.