We manufacture our range of Celcon Blocks in three state-of-the art factories in Kent and Yorkshire. Our Borough Green factory, recently the subject of a major rebuilding programme, is the most modern and efficient aircrete factory in Europe, and we benefit from the experience and knowledge of our technical experts from our plants across Europe.
What is Aircrete?
Aircrete is a lightweight masonry material, combining the strength, durability and thermal efficiency of concrete with the ease of use that comes with a lighter material, easy to cut and work on site.
The materials used in the manufacture of H+H Aircrete are: sand, pulverised fuel ash (PFA), cement, lime and water. These are combined into a slurry and small amount of aluminium powder is added to the mix. This initiates a chemical reaction, generating minute bubbles which form the characteristic aicrete structure and appearance.
When the mixture has partially set, the resultant “cakes” are wire-cut into blocks or panels and transferred into autoclaves for high pressure curing.
The Origins of Aircrete
Originally known as cellular concrete, aerated concrete was first produced in Scandinavia in 1924. At this time the cellular concrete was made from Portland cement, water and a foaming agent. After mixing, it was poured directly into the required position on site and used primarily for insulating roof screeds and underground pipe insulation.
In the 1950s Celcon developed the process to manufacture aerated concrete into blocks and Danish scientists added pulverised fuel ash (PFA). A waste product from coal-fired power stations, the PFA gives the product strength, yet makes it light enough to pick up with one hand.
H+H aircrete manufactured in the UK is traditionally comprised of 80% PFA, giving excellent sustainability credentials as well as great performance. Sand is also used in the mix and, depending upon the availability of PFA.