Autoclaved aerated concrete block is composed of calcareous and siliceous materials. The porous structure is formed by chemical gas generation method, and the lightweight artificial stone with high strength is obtained through autoclaved curing. It can be said that autoclaved aerated concrete block is a kind of autoclaved porous silicate concrete with special chemical aerating method. At present, autoclaved aerated concrete block products are important raw materials for the frame structures of various high-rise buildings, high precision, heat preservation，which can save a lot of land and a lot of energy, but also can turn waste into treasure, purify the environment, reduce pollution, which has both good economic benefits and significant social benefits.
First, the bulk density of the product
Autoclaved aerated concrete blocks can have a variety of bulk density, which is usually divided into four levels according to the mass of dried products per unit volume, 500, 600, 700, 800, and the mass deviation of each level is allowed to fluctuate within ±50kg/m3. At present, the main production and use of 500, 600 grade products in the Chinese market. Class 600 products are mainly load-bearing and also serve as heat preservation. Grade 500 products can be used as load-bearing materials and non-load-bearing materials (filling materials) for some units, as well as heat preservation.
Two, compressive strength
The compressive strength of autoclaved aerated concrete blocks varies with its bulk density and production process. Generally speaking, the bulk density is higher, and the products with the same bulk density have different strengths due to different production processes. Autoclaved aerated concrete block generally weighs 500-700 kg/m3, which is only equivalent to 1/4 to 1/3 of clay brick and mortar brick and 1/5 of ordinary concrete. It is a lighter kind of concrete and is suitable for filling walls of high-rise buildings and load-bearing walls of low-rise buildings. Using this material, the weight of the whole building can be reduced by more than 40% compared to the weight of ordinary brick and concrete structures. Because the building weight is reduced, the earthquake damage is small, so greatly improve the seismic capacity of the building.