What are Foam Concrete Forms?
Foam concrete is actually a lightweight, fluid cellular concrete fill product that is produced by mixing cement paste like mortar or slurry with pre-formed foam that is manufactured separately. The ratio of the foam to the slurry determines the density of foam concrete forms. Densities usually range between 300 – 1600 kg/m3. Its properties are enhanced further with the use of fuel ash that is pulverized, sand, limestone dust or Lytag fines.
Sometimes, it can be hazardous or difficult to undertake the placement and mechanical compaction of the fill material if work has to be done in conditions that are unstable or provide limited access.
Why Use Foam Concrete Forms?
Foam concrete allows rapid and easy installation. It can be pumped easily in low pressures and over very long distances. It is a great void filler. It is a natural self leveling material that reaches and fills smallest cavities, seams and crevices. A mobile batching unit is able to produce more than 100 m3 of these concrete forms having densities of 400 kg/m3 from a single tanker delivery of bulk powder. This results in less disruption as well as more safety for the residents and site workers in the immediate area.
Rapid installation, high volume equipment makes void fill by insulated concrete forms a solution that is economically viable, especially in applications of large volume. The properties of settlement free and durability of this concrete reduce the liability of future maintenance. Minimal loading laterally means reduced cost of construction for structures retaining the earth. Piled foundations are not required if foam concrete is used for construction on a marginal ground.
As these forms have low densities like 300 kg/m3, they impose negligible stress vertically on surrounding substructures which is vital in areas that are susceptible to settlement. If excavations are done in poor soil, the lightweight concrete forms lightweight, 100% stable foundations. It could be designed with the help of the equilibrium principle. This is done by replacing weight of excavated soil with a lower or similar combined weight of the concrete foundation as well as construction so that the ready structure is stable and capable of resisting any movement of sub-strata.
Styrofoam concrete forms provide good thaw/freeze resistance. The main reason for this is the characteristic of low absorption of water whereby the absorption of capillary water does not reach the point of maximum saturation that could result in damage.
Unlike the polystyrene synthetic foams that are used in construction, foam concrete that is hardened will not breakdown because of the presence of fungi, bacteria or hydrocarbons. Styrofoam forms are fire, rodent and insect proof. Foam concrete has a dense cellular structure due to which its resistance increases by absorbing the kinetic energy when it is compressed at the time of impact. This is particularly useful when designing arrestor systems at airports or roads.
Foam concrete forms provide numerous benefits over the other concrete forms. They also have several other applications which is why they are becoming increasingly popular in the construction industry.