Environmental benefits of Light Concrete - AAC
The use of AAC has a range of environmental benefits:
Insulation:
Most obviously, the insulation properties of aircrete will reduce the heating costs of buildings constructed with autoclaved aerated concrete, with consequent fuel savings over the lifetime of the building.
Materials:
Lime is one of the principal mix components and requires less energy to produce than Portland cement, which is fired at higher temperatures. Sand requires only milling before use, not heating, and PFA is a by-product from electricity generation. NB: lime may require less energy to manufacture compared with Portland cement but more CO2 is produced per tonne (cement approx. 800-900 kg CO2/tonne compared to lime at 1000 kg CO2 per tonne).
Carbonation:
Less obviously, the cellular structure of aircrete gives it a very high surface area. Over time, much of the material is likely to carbonate, largely offsetting the carbon dioxide produced in the manufacture of the lime and cement due to the calcining of limestone.
