Autoclaved aerated concrete, also known as autoclaved cellular concrete (ACC) and autoclaved lightweight concrete (ALC), is a precast building material which is thermally insulating, easily shaped, highly workable, fire resistant, acoustically insulating, water and mold resistant, and can be used in both and non-structural applications. It is an ultra-light concrete masonry product offering superior workability, durability, and flexibility. AAC consists of basic materials such as sand, cement, fly ash, lime, aluminum powder paste, gypsum, and water. The chemical reaction between aluminum paste and alkaline elements in the cement provides AAC with lightness, distinct porous structure, and insulation properties which are completely different from other lightweight concrete materials.
AAC has manufacturing, embodied energy and greenhouse gas emission impacts similar to those of concrete based on weight, though it is one-quarter to one-fifth that of concrete based on volume. AAC products or building solutions have lower embodied energy per square meter than a concrete alternative. Additionally, AACs much higher insulation value reduces energy consumption required for heating and cooling. AAC possess significant environmental advantages over conventional building materials, such as insulation, longevity, and structural demands in one material. Total energy consumption for producing ACC is less than half of what it takes to produce other building material. AAC helps to reduce at least 30% of environmental waste than traditional concrete. Moreover, a decrease of 50% of greenhouse gas emissions can be achieved. Autoclaved aerated concrete is a better choice for the environment, and meeting the requirement for the construction of green buildings.