By: Allison Carlisle MEEN-3344

What is it? Autoclaved aerated concrete(ACC) is a porous, lightweight, concrete-like material made with many small aggregates. AAC is 80% air. It can weigh about 1/6 to 1/3 as much as normal concrete and can be just as strong with reinforcement and a protective finish. Where? How long in use?

How it’s Made Raw materials such as limestone, water, sand, and often fly ash are mixed with cement. A reactive expansion agent such as aluminum powder is added to create air bubbles and cause expansion. The mixture is poured in large molds with After it sets, it is wire cut into precisely sized blocks and then baked. Reinforcement is placed within the molds prior to the curing. It is then baked to speed up the curing process and help maintain their dimensions.

How it’s Made

Properties Density: lbs. per cubic ft. Compressive strength: psi Allowable Shear stress: 8-22 psi Thermal resistance: in. of thickness

Uses AAC combines insulation and structural capability for floors and roofs. Its light weight properties make it easy to cut, size, and adjust for complex jobs It’s a cement-based material, so it can resist water, mold, insects, and is mostly fire resistant.

limitations Made in rigid, pre-sized panels Because it has a lower strength in most load-bearing applications, it is typically reinforced. Also requires a protective finish since it is a porous material and would deteriorate if left exposed. (usually a stucco-type finish) Not readily available in America but can be easily shipped

Applications and cost Commonly used in everyday buildings such as commercial and residential places. Also can be used for thermal insulation, plumbing and electrical conduits. Ensures structural integrity and tightness. Cost can be expensive varying from the size needed and distance that it has to be shipped

Summary It’s a light weight It is versatile and durable. Easy to adjust and size if mistakes or changes are made Great for complex, and smaller jobs such as plumbing areas.

Bibliography Jardine, Kathleen, Cameron,James, Sungarden Houses, Inc., Web, 2012, Lionheart Publishing, Inc., Using Autoclaved Aerated concrete Correctly, Mason Contractors Association of America, Web, 2008, masonarymagazine.com Portland Cement Association, Autoclaved Aerated Concrete, Web, 2012,