Invented in Sweden in 1924 AAC is a lightweight, precast, foam concrete building material that simultaneously provides structure, insulation and fire and mold-resistance.
In the product’s manufacture, Portland cement is mixed with a lime, silica sand, water, expansion agent and poured into a mold. The reaction between the expansion agent and concrete causes microscopic hydrogen bubbles to form, expanding the concrete to about three times its original volume. After evaporation of the hydrogen, the now highly closed-cell, aerated concrete is cut to size, form and steam-cured in a pressurized chamber (an autoclave). The result is non-organic, non-toxic, airtight material that can be used in non- or load-bearing exterior or interior wall, floor and blocks.