AAC block, also known as Autoclaved Aerated Concrete block, is a lightweight concrete masonry material used for construction purposes. It is made from cement, lime, silica sand, water, and aluminum powder. It is formed into blocks and then cured in an autoclave chamber. AAC block is typically used in residential and commercial buildings for wall, floor, and roof construction. It has many advantages over traditional masonry materials, including improved thermal and sound insulation, fire resistance, and earthquake resistance.