Foam concrete can be used as flooring

Foam concrete - what is it?

Properties of foam concrete

Foam concrete is a specially manufactured concrete. It contains special foaming agents that create air cushions when the concrete hardens. In practice, its bulk density is between 0.4 and 1.6 kg / dm³. This makes it a very light and stable material.

Foam concrete is very light and flowable. It can also be pumped. Foam concrete does not have to be compacted during installation. This would also make no sense with regard to the desired air inclusions.

Components of foam concrete are:

  • cement
  • water
  • Aggregate (only up to 2 mm)
  • Foaming agent or finished foam

Alternative names

Foam concrete is also known as lightweight aerated concrete (PLB). Foam concrete is only used to describe concrete types that have an air void content of more than 30 percent by volume in the finished concrete.

Production of foam concrete

The production can be done in different ways. As a rule, foam concrete is produced directly on the construction site in the compulsory mixer itself.

A foaming agent can either be added to the concrete - in this way, however, only foamed concrete with a maximum density of 1.4 kg / dm³ can be produced.

If a more dense foam concrete is required, a foam device is used. The foam generated by the foam device is mixed directly into the already finished concrete on the construction site, thus creating foam concrete. The process can be used with almost any type of fresh concrete.

Use of foam concrete

Foam concrete is used wherever low weight and high stability are important. This is for example:

  • in earthworks as a light filler material that also reinforces soils that are less stable
  • in civil engineering for backfilling
  • on flat roofs
  • as an intermediate layer in buildings when weight is to be saved
  • as a thermal insulation layer or a particularly light and thermally insulating base layer
  • in some cases also for backfilling canals or trenches as well as tunnels

Foam concrete standards

Foam concrete is not standardized concrete. Accordingly, DIN EN 206-1 and DIN 1045-2 do not apply to foam concrete. If necessary, this must also be taken into account when used in buildings. There are no binding standardized values ​​in DIN for load-bearing capacity and stability.

Thermal insulation properties

Foam concrete is very good thermal insulation due to the high number of air pores. The higher the number of air pores, the better the thermal insulation properties, but the lower the strength. Both values ​​can be set for foam concrete via the bulk density. The so-called dry bulk density is used here as the setting value.

In the case of foam concrete with a bulk density of less than 1 kg / dm³, you must take special measures in the composition and manufacture, but also in the installation. In general, the use of foam concrete with such a low bulk density is not advisable, especially not in construction.