FOAM CONCRETE

What Is Foam Concrete?

Foam concrete is a highly fluid, lightweight cellular concrete fill material made by combining a cement paste (slurry or mortar) with a prepared foam that has been generated separately.

The ratio of foam to slurry determines the density of foam concrete, which usually ranges from 300 to 1600 kg/m3. To further improve the qualities of foam concrete, sand, powdered fuel ash (PFA), quarry dust, or limestone dust can be used.

In general, it is a type of concrete that contains no big aggregates and just fine sand and cement, water, and foam. Because it does not include coarse material, it can be regarded as reasonably homogenous compared to ordinary concrete.

The microstructure and content of foamed concrete, on the other hand, are determined by the kind of binder employed, as well as pre-foaming and curing techniques.

Components Of Foamed Concrete

1.          Water,

2.          Binder,

3.          Foaming agent,

4.          Filler,

5.          Additive, and

6.          Fiber.

How To Prepare Foamed Concrete

The pre-foaming method and the mix-foaming method are two strategies that may be used to produce this concrete. Both methods manage the mixing process and quality of foamed concrete .

The pre-foaming course includes separately preparing the base mix and stabilizing the preformed aqueous foam. The foam is then thoroughly mixed into the foundation mix.

Either a dry or a wet process might be used to create the preformed foam. The dry foam is created by simultaneously forcing compressed air and a foam agent solution through a series of high-density restrictions inside a mixing chamber.

The dry foam is highly stable and produces bubbles smaller than 1 mm in diameter. The microscopic bubbles allow for a consistent and homogenous foam mix with the base material, resulting in pumpable foamed concrete.

Spraying the foam agent solution through a fine screen produces wet foam. The size of wet foam bubbles is usually between 2 and 5 mm, and the foam generated is less stable than dry foam.

During the mixing phase of the mixed foaming technique, the surface-active agent is practically combined with base-mix ingredients, notably cement slurry. The foamed concrete develops a cellular structure due to the produced foam.

The foam used should be firm and sturdy to withstand the mortar pressure until the cement sets. It aids in the formation of a sturdy concrete framework throughout the air-filled space.

Advantages of Foam Concrete

·                     Foam concrete is light in weight. The adjacent sub-structure is not subjected to much vertical stress.

·                     It has minimal heat conductivity and excellent sound insulation qualities that regular concrete lacks.

·                     It is resistant to freezing and thawing.

·                     Foam concrete is free-flowing concrete that does not need to be compacted. Foam concrete adheres to any subgrade contour when used in foundations or excavations.

·                     This concrete can be easily pumped over a long distance with relatively little pressure.

·                     It is a substance that lasts a long time. It will not decay and will last as long as a rock.

·                     This concrete has a low permeability coefficient.

Disadvantages

·                     The compressive and flexural strength of foam concrete decreases as its density decreases.

·                     Because foam concrete has a higher paste concentration and no coarse aggregate, it shrinks more than regular concrete.

·                     Because it contains more cement than ordinary concrete, as a result, it gets expensive.

·                     The linked pore to total pore ratio has a significant impact on foam concrete’s longevity.

·                     The time it takes to mix foam concrete is longer.

Conclusion

The first findings indicate that foam concrete has sufficient strength to be used as an alternative construction material in the industrialized building system. For lower density mixtures, the strength of foam concrete is minimal.

Because of the significant reduction in overall weight, structural frames, footings, and piles may be saved, and construction can be completed quickly and easily.