ecobrick autoclaved concrete bricks are produced using a German autoclaved process which, on a single shift basis, can produce bricks at the rate of 50,000 cubic metres per annum.
The plant has a maximum capacity of 150,000 cubic metres per annum.
The manufacturing process developed in Sweden in the 1920’s has since been widely used to produce aerated concrete bricks for domestic and commercial construction in Europe, Japan, United States of America and now in Australia.
The Wehrhahn plant installed by ACT incorporates the latest available computerized process control instrumentation and techniques necessary for the manufacture of consistently high quality lightweight concrete.
The basic materials used in the manufacture of ecobrick autoclaved concrete bricks are sand, cement, lime and water.
The finished product is the result of a highly complex chemical process.
A slurry is produced by mixing milled sand with water. The slurry is introduced into high speed mixers where it is mixed with cement and lime. Finally, a small quantity of aluminium powder in suspension is added and evenly dispersed.
After mixing, the cement slurry is poured into a mould. The aluminium paste reacts with the alkaline elements in the cement and forms hydrogen gas.
The liberated gas expands the mixture forming extremely small, finely dispersed air spaces. The product is removed from the moulds after a few hours and fed into a cutting machine. The cutting machines section the slabs, using cutting wires, into the required size bricks.
The moulds of cut bricks are then placed in autoclaves where they are steam cured at a pressure of approximately 12 atmospheres. This steam curing process causes a further chemical reaction, combining lime and silica to produce complex calcium silicate hydrates, which govern the properties of the finished material.
The bricks are removed from the autoclave and are packed, ready for transport to the building site.
