What is Autoclaved Aerated Concrete or AAC?

AAC is a light-weight masonry and pre-cast concrete product used for residential and commercial structures (homes, hotels, apartments, schools, hospitals, sound and fire walls, etc.). The product line consists of blocks, reinforced wall and floor panels, lintels, and various other units.

AAC was invented during the early 1900's and has been in wide use in Europe for over 70 years. It has underwent rigorous testing in the U.S. and meets ASTM International, Underwriters Laboratories, and ICC-ES specifications for construction.

What is AAC made of?

AAC is made by combining a small amount of cement and lime with an aggregate such as sand or other material* (*see "Did You Know?" sidebar).

These ingredients are then mixed with water into a batter or 'slurry' and further combined with an expansion agent. This expansion agent works as a catalyst, much as yeast does for baking, creating millions of microscopic air pockets that makes the slurry rise and set.

How is AAC made?

The slurry is poured into large molds. After the slurry has set (pre-cured), the molds are removed and the cake is cut into the various building blocks and panels that make up an AAC product line. The material at this point is similar to clay in density.

After cutting, the material is placed into an autoclave. This machine works similar to an oven, but uses pressurized steam to cure and strengthen the material. Following the autoclave, the material has hardened and is ready for packaging and shipping.

This process produces only water as waste and uses 80% less energy than concrete or lumber manufacturing. AAC's production also cleans up wastes from other manufacturing projects (when aggregates such as fly-ash or mine tailings are used), helping our environment.

view a diagram of our manufacturing facility