ALC is the abbreviation of Autoclaved Lightweight Concrete and is a type of high-performance autoclaved aerated concrete (ALC). ALC board is a porous concrete formed board (containing processed steel reinforcement) made of fly ash (or silica sand), cement, lime, etc. as the main raw materials and cured by high-pressure steam. ALC board can be used as both wall material and roof panel. It is a new building material with superior performance. ALC boards first appeared in Europe, and have a production and application history of more than 40 years in Japan, Europe and other regions. At present, the production technology and production equipment of domestic manufacturers are mainly imported from Japan and Germany.