Autoclaved Cellular Concrete (AAC), also known as Autoclaved Cellular Concrete (ACC), Light Autoclaved Concrete (ALC), Autoclaved Concrete, Cellular Concrete, Porous Concrete, Aircrete, Hebel Block and Ytong is a lightweight construction material. Of the 1920s which simultaneously provides structure, insulation, resistance to fire and mold. AAC products include blocks, wall panels, floor and ceiling panels, facade panels and lintels.
The autoclaved aerated concrete (AAC) material was developed in 1924 in Sweden. It has become one of the most widely used building materials in Europe and is growing rapidly in many other countries around the world.
AAC is produced from common lime, sand, cement and water materials, and a small amount of upstream agent. After mixing and molding, it is then autoclaved under heat and pressure to create its unique properties. AAC has excellent thermal insulation and acoustic absorption properties. AAC is resistant to fire and pests, and is economically and environmentally superior to more traditional structural building materials such as concrete, wood, brick and stone.
As the AAC mixes and melts into structures, some composite responses occur that give AAC its light weight (20% of the weight of cement) and warm properties. The aluminum powder responds with calcium hydroxide and water to frame the hydrogen. Hydrogen gas foam and copies the bulk of the gross mixture that causes the gas to rise to 3 mm (⅛ inches) away. Towards the end of the foaming process, the hydrogen escapes into the air and is supplanted by air.
AAC Blocks is a unique and excellent type of building material due to its super heat, fire and sound resistance, the AAC blocks are lightweight and offer maximum workability, flexibility and durability. Its main ingredients are sand, water, quicklime, cement and plaster. The chemical reaction due to the aluminum paste provides AAC its distinct porous structure, lightness, and insulation properties, completely different compared to other lightweight concrete materials.
When the shapes are removed from the material, it is solid but still smooth. It is then cut into blocks or panels and placed in an autoclave chamber for 12 hours. During this process of vapor pressure hardening, when the temperature reaches 190 ° C (374 ° Fahrenheit) and the pressure reaches 8 to 12 bar, the quartz sand reacts with the calcium hydroxide to form hydrated calcium silicate, Which gives AAC its high strength and other unique properties. Due to the relatively low temperature, the AAC blocks used are not considered baked bricks, but a lightweight concrete masonry unit. After the autoclaving process, the material is ready for immediate use at the construction site. Depending on its density, up to 80% of the volume of an AAC block is air. The low density of AAC also explains its low resistance to structural compression. It can carry loads up to 8 MPa (1,160 PSI), approximately 50% of the compressive strength of regular concrete.
AAC offers incredible opportunities to increase the quality of the building and at the same time reduce costs on the construction site. AAC is made from a mixture of quartz sand and / or pulverised fly ash (PFA), lime, cement, gypsum, water and aluminum and hardens by steam curing in autoclaves. As a result of its excellent properties, AAC is used in many building constructions, for example in residential houses, commercial and industrial buildings, schools, hospitals, hotels and many other applications. AAC contains 60% to 85% air by volume.