Foamed concrete” is made by adding foaming agent into a mixed mortar in a truck-mixer. Foamed concrete is a nonstructural void filler that can be dug out with excavators. It is used for trench backfill and similar applications. The air content is over 50%, compared with about 5% in air entrained concrete.

Advantage

It has a lightweight. It imposes little vertical stress on the surrounding sub-structure.
It has low thermal conductivity and good sound insulation properties which are not available in ordinary concrete.
It has excellent freeze and thaws resistance.
Foam concrete is a free-flowing concrete and can be placed without compaction. When placing in foundation or excavations, foam concrete conforms to every subgrade contour.
Foam concrete can be pumped easily with relatively low pressure over a long distance.
Foam concrete is very long-lived material. It does not decompose and it is as durable as rock.
Foam concrete has a low coefficient of permeability.