Foam Concrete Specification

The foam concrete specification is designed for the construction of lightweight structures that have a high workability, low self weight and minimal consumption of aggregate. It has good thermal insulation properties and can be used to create light weight walls in a building.

The material is made by mixing cement, sand or fly ash and a foaming agent (naturally such as tannic extracts of leather, sub soaped lye, sulfite lye etc) with water in specialised generating equipment and compressed air to produce pre-formed foam. The resulting foam is mixed with the cement mortar mix to produce the final cellular lightweight concrete, often with a higher volume of cement than normal concrete.

Foam concrete is produced with a range of densities, from 1800kg/m3 up to 1600kg/m3. Heavier density mixes have a higher strength, but fewer pumps, so are usually manufactured and pre-blended.

This method can be carried out in a ready-mix truck, where the base mix is delivered to site through the mixer, and the pre-formed foam is injected into the truck. This is used for small works like grouting or trench filling where there are minimal quantities required.

Propump have designed a range of foam concrete mixes over the years with differing water / cement ratios, volumes of aggregates, foam and admixtures. Generally, common strengths that specifiers choose range from 1N/mm2 to 5N/mm2. However, higher strength foamed concretes up to 10N/mm2 can be produced when requested.