All-solid-waste alkali-activated materials: A critical review of multi-waste synergy, heavy metal stabilization, and sustainable engineering applications

Abstract

The cement industry’s substantial carbon emissions and the increasing accumulation of industrial solid waste pose significant challenges to achieving sustainable development in the construction sector. Alkali-activated materials (AAMs) have emerged as promising low-carbon alternatives that offer high mechanical performance and reduced environmental impact. However, their widespread adoption is limited by the high cost and environmental risks associated with conventional strong alkali activators. All-solid-waste alkali-activated materials (ASW-AAMs) provide an innovative “waste-treats-waste” strategy through the synergistic substitution of conventional strong alkalis with alkaline industrial byproducts. This approach aligns with principles of resource efficiency and environmental protection. Despite its promise, the development of ASW-AAMs faces several critical challenges, including variability in raw material composition, incomplete understanding of reaction mechanisms, and inadequate long-term performance data. To address these issues in a systematic manner, this review investigates three key research domains, namely, the synergistic optimization of multi-source solid waste co-processing, the mechanisms that govern the regulation of mechanical properties, and the micro-scale elucidation of hydration reaction dynamics. Furthermore, the study emphasizes the indispensable role of molecular dynamics simulations in unraveling atomic-scale reaction mechanisms. It also explores the potential of machine learning-based approaches for predictive modeling. These insights contribute to the establishment of a foundational framework for the industrial implementation of ASW-AAMs. By enabling the transformation of industrial byproducts into high-performance construction materials, ASW-AAMs offer a viable pathway toward decarbonization and the advancement of circular economy objectives in the construction industry.