Which type of concrete is referenced as AAC?

Autoclaved Aerated Concrete, commonly referred to as AAC, is a lightweight precast concrete building material that is known for its thermal insulation properties and its ability to resist fire. It is made from a mixture of quartz sand, water, lime, and cement, with the addition of an expansion agent such as aluminum powder. This mixture is then poured into molds and subjected to high pressure and temperature in an autoclave, which causes the mixture to expand and cure, resulting in a material that is not only lightweight but also has excellent insulation qualities.

AAC is often used in construction for walls, roofs, and floors, providing a sustainable alternative to traditional concrete because it can be produced with less energy and raw materials. Its notable characteristics include ease of handling on the job site and reduced weight compared to conventional concrete, which can lead to lower transportation and foundation costs.

In contrast, the other options provided do not represent standard terminology in the concrete construction industry and thus do not accurately describe AAC.