The product covered in this EPD is a generic 1m3 of precast aerated concrete blocks. Aerated concrete blocks, commonly referred to as Aircrete, are lightweight, autoclaved, thermal insulation blocks normally used as internal masonry blocks. As a result of the raw materials and manufacturing process, the cellular (small bubbles) internal structure of the blocks gives a low density but good compressive strength.
Unlike most other concrete products, the Aircrete manufacturing process uses a combination of natural hydration reactions and accelerated curing processes. The concrete mix is essentially a very fine grained mixture of cement, lime, pulverised fly ash (PFA) and sand with water. Variations to this mix design exist with some ground sand blocks not containing PFA. To this, finely powdered aluminium is added. The reaction between the constituent materials releases hydrogen gas which gives the product its aerated structure.
The aeration process takes place in moulds and, once an initial set has occurred, the blocks are loaded into autoclaves where they are steam cured.
Primary data for the production of aerated concrete blocks were collected from members of the Aircrete Products Association (APA), a product group of British Precast. This data were used to generate a mass weighted average of production for the EPD.
Generic Autoclaved Aerated Concrete Block
02 Building products
Normal/lightweight/autoclaved aerated concrete products
British Precast (APA)
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Aerated concrete (PCR)