FOAMED CONCRETE - WHAT IT IS

The most basic definition of foamed concrete is that it is ‘mortar with air bubbles in it.’ The air content of foamed concrete may be up to 75% air by volume.

In general terms, foamed concrete can be described as a lightweight, free flowing material which is ideal for a wide range of applications. It can have a range of dry densities, typically from 400 kg/m3 to 1600 kg/m3 and a range of compressive strengths, 1 MPa to 15 MPa (1).

Foamed Concrete can be placed easily, by pumping if necessary, and does not require compaction, vibrating or levelling. It has excellent resistance to water and frost, and provides a high level of both sound and thermal insulation. It is very versatile, since it can be tailored for optimum performance and minimum cost by choice of a suitable mix design.

The fact that foamed concrete can be made using different mix designs means that it is not a single product. With the exception of pre-cast units, foamed concrete cannot be bought ‘off the shelf’. Foamed concrete is nearly always made on-site and it is made using a mix design specifically selected for each application or job.

Although the material is called foamed concrete, it is not really concrete at all. Foamed concrete is actually foamed mortar, where the mortar is made from either cement and water or sand, cement and water. Foamed concrete does not contain aggregates.

Foamed Concrete is not the same as conventional concrete and does not have the same characteristics.

Foamed concrete is much lighter and does not have the same strength as conventional concrete. For this reason foamed concrete and conventional concrete are generally used for different applications, although there are applications where either may be specified.

Foamed Concrete is not the same as autoclaved aerated concrete, which is a common building material that is frequently confused with foamed concrete. Foamed concrete is a much more versatile material than autoclaved aerated concrete, the latter being restricted in its form and where it is made.