Key raw materials in aircrete are nature's own sand, water, lime and cement.
The sand is ground in a ball mill and then mixed in an aqueous solution with lime and cement. Aluminium powder is added before the mass is poured into moulds. Aluminium powder is the aerating agent providing the important product properties thermal insulation and lightness. When reinforcements are used in the products, reinforcement structures are placed in the production moulds before these are filled.
The still wet mass is then cut into desired sizes, which are autoclaved under steam pressure. Following autoclaving, the products are packed and covered with a protective plastic hood. The products are then ready for shipment or storage.
In the UK and Poland, siliceous sand is completely or partly substituted by high-quality pulverised fuel ash wherever possible. Pulverised fuel ash is a spin-off product from coal-fired power stations that gives the product good properties in relation to moisture-induced movements (shrinkage/swelling properties).
Simple though the recipe may sound, vast know-how and experience is the basis for a successful result. All stages in the production are important – from raw material composition, mixing, rising to autoclaving. All factors determining the weight, strength and insulating value of the finished aircrete.
H+H has, during many years, achieved a solid experience in producing aircrete. The know-how, experience and research have enabled a robust manufacturing process and, most importantly, products with strong product properties for the construction industry.