Autoclaved cellular concrete (ACC) is a lightweight, precast concrete building material developed in Sweden in the late 1920's. ACC can be manufactured in a variety of shapes and sizes allowing for maximum flexibility and efficiency in construction. It is different from lightweight aggregate concrete and other types of concrete because it is composed of millions of microscopic cells generated during the manufacturing process. This process involves steam curing the concrete in a high-pressure autoclave. ACC has numerous superior qualities that make it attractive as a building material: it is lightweight, has a high compressive strength, provides good insulation and fire resistance, and provides good workability and durability. It has almost limitless applications in the construction industry.