Light weight concrete is a mixture of cement, water and special foam, which produces a strong a lightweight building material combining good mechanical strength with low thermal conductivity.

In Europe and western countries it is used primarily to reduce the weight of the concrete building. However tropical Asia and Africa the principle objective of using the material are its excellent thermal insulation properties.

The thermal insulation properties are bought about the millions of evenly distributes consistency sized are bubbles, which gives the concrete its fine cellular structure.

The bubbles ideally should be between 0.3 mm and 0.8 mm in diameter. A mixed with such property will be free flowing, easily pumped and will not segregate or bleed. The consistency of the mixture is normally assured by the quality of the foam

Produced in terms of bubble size and its imperishability while mixing with cement and water.

In the Middle East, the normal density used would normally vary between 450 - 800 kg/m3 .based on requirement and the specification prescribed. Foam concrete of these densities is made with neat cement.

Aggregates such as sand and stone dust are used when higher densities are required usually when the finished surfaces are prone to be under traffic with heavy loads and therefore require higher Comprehensive strength.

When foam concrete is caste in-suit, as in the case of roof insulation, care should be taken to see that the ensuing shrinkage is taken care of. While hairline cracks are normal in the case of roof insulation, limiting the depth if depth of casting and allowing a setting an interval between consecutive casts ensures quality of set foam.

The table indicates the different density of lightweight concrete for various purposes.