Waste clay brick utilization in alkali-activated materials: A review on fresh and hardened state properties

The demand for new alternative sustainable binders has grown in recent years, seeking to reduce the environmental impact embodied in the use of Portland cement-based materials in the construction industry. Alkali-activated materials (AAMs) are a significant focus of investigation because of their capability of lowering CO₂ emissions and the valorization of aluminosilicate wastes. Besides the valorization of wastes, commonly used precursors such as slags and fly ash have their use focused on cement blend production and may have their availability reduced soon, resulting in the need for new materials to be used as precursors in AAMs. Waste clay brick (WCB) is a type of aluminosilicate solid waste material that is recyclable in the construction industry, particularly in AAMs. This review synthesizes current knowledge and insights regarding the application of WCB in AAM manufacturing. It underscores the necessity for further research on engineering properties, including rheology and reaction kinetics, to enhance our understanding of WCB-based AAMs. Additionally, this review aims to provide a comprehensive overview of the existing literature and guide future investigations in this emerging field.