Concrete @ your Fingertips

Foamed Concrete

Foamed concrete is a highly aerated mortar/paste, typically containing 30 to 80% air bubbles by volume . It comprises Portland cement (fast setting non-Portland cements are also available), water, fine aggregate/filler (usually omitted for densities below 1000 kg/m³) and mechanically produced (preformed) foam. It has high workability, which allows it to flow and compact under its own weight.

Typical plastic densities of foamed concrete are from 400 to 1600 kg/m³ (i.e. they are generally lighter than controlled low strength mortar and lightweight aggregate concrete). Final dry densities are between 100 and 300 kg/m³ lower than ´normal concrete´ depending on the prevailing conditions.

Compressive strengths, determined from sealed cubes, range from 0.5 to 5 N/mm². However, strengths of around 25 to 30 N/mm² are feasible for foamed concretes with higher densities.Typically, low strengths are sought for void and trench filling applications and the higher strengths are used for load-bearing applications such as house foundations and slabs.

Acknowledgement: Dundee University

Concrete Bookshop - Members receive 40% discount on Concrete Society publications

Foamed concrete - GCG7