Foam concrete, also known as lightweight cellular concrete, offers a lighter alternative to traditional concrete. Foam concrete is made with a liquid concrete slurry instead of coarse aggregate, and is suitable for applications such as void filling applications, highway sub-bases or insulation floors.
Foam concrete is a highly air entrained sand cement that has at least 20% air by volume in the set product. It is made with a cement slurry and can range as high as 85% foam or air content. Most foam concrete applications require at least 50% foam or air by volume.
To foam the concrete, air is entrained mechanically with a pre-formed foam. This is mixed with the cementitious base material in order to create a low-density composite material.The densities of set foam concrete are also tunable. They range from around 400 kg per m3 to 1,800 kg per m3, and strengths can range from 0.5 N per mm2 to 12 N per mm2.
Foam concrete is also known as foamed concrete, or lightweight cellular concrete (LCC), low-density cellular concrete (LDCC), aerated lightweight concrete, cellular lightweight concrete, and various other industry or brand-specific terms as well as (perhaps more accurately) foamed mortar, foamed grout, and foamed cement.
It is made mostly without coarse aggregate, instead using a liquid concrete slurry. This is why foamed mortar, grout, or cement are perhaps more accurate descriptions of the material. Density is controlled by substituting some or in some cases all of the fine aggregate with foam products.
Fly ash and sand typically make up the fine aggregate material, which is mixed with water and cement. Some manufacturers recommend using only water and cement plus the foaming agent to produce extremely lightweight concrete mixes.
The concrete slurry is combined with an aerated foam product in a concrete mixing plant. To make the foam, manufacturers mix a foaming agent with water and air from a generator. It produces consistent bubbles with high levels of stability in order to resist the chemical and mechanical strains of concrete mixing, pouring, placing, and setting.