Ceramics-Silikáty

Alkali‑activated foam concrete (AAFRC) is an emerging low‑carbon, lightweight porous material with considerable potential for sustainable construction. This review summarizes current knowledge of AAFRC, including raw material systems, alkali activation mechanisms, foaming processes, pore structure development, and durability performance. The roles of high‑ and low‑calcium precursors are discussed in relation to gel formation, reaction kinetics, and microstructural evolution, together with the influence of the activator type, modulus, and concentration on material properties. Physical and chemical foaming methods are analysed in terms of foam stability, rheology, and pore formation mechanisms. Particular attention is given to the relationships between pore structure characteristics (porosity, pore size distribution, and connectivity) and mechanical and durability performance. Key durability aspects, including freeze–thaw resistance, high‑temperature behaviour, chemical resistance, carbonation, and drying shrinkage, are critically evaluated. Although AAFRC demonstrates promising performance, challenges remain, particularly related to shrinkage, pore instability, and a limited understanding of long‑term behaviour under coupled conditions. Recent advances in superhydrophobic modification are highlighted as promising approaches for enhancing durability by reducing water ingress. Future studies should focus on multiscale modelling, improved process control, and standardized design methods to enable broader practical application.