Foam concrete: production technology of high-quality

The modern construction market offers many high-quality materials, but the construction of foam blocks occupies a special niche. They are cellular cellular concrete - the strength characteristics of this material make it possible to use it as the main structural element in low-rise construction.

A few words about the properties and merits

Before talking about the characteristics should understand what foam concrete. This building material belongs to cellular types of concrete, that is, in its composition there is a certain amount of air pores. Classically, it is produced by adding water and a whipped foam to the cement-sand mixture.

Important: Aerated concrete is the closest cellular competitor of foam blocks. But the pores of aerated concrete are open, as a result, this material behaves like a sponge and is afraid of high humidity. The pores of the foam blocks are closed and the material can even hold onto the surface of the water.

Production methods

The basic, classic production technology is considered to be a system consisting of 2 stages. Separately preparing the foam for the solution and the cement-sand mixture, after which they are combined and thoroughly mixed in a special mixer. Next, the prepared solution is poured into forms and freezes.

Technical characteristics of foam concrete largely depend on the quality of foam preparation. To ensure this process, a foam generator is used - compressed air is supplied to it by the compressor, and the foam-forming composition is whipped to the desired consistency. The main quality of foam is the level of its vitality or how long it can last.

Tip: if you decide to do foam blocks with your own hands, then the quality and density of the foam can be checked by filling it with an ordinary bucket and turning it over. A well-made compound will not flow and will remain in the bucket.

There have been attempts to simplify the technology and make it one-step. The essence here is that a foaming agent is added to the cement-sand mixture and, under high pressure, the solution is whipped with a mixer at high speed. Something similar to whipping eggs, but, despite the apparent simplicity, these attempts were not crowned with success.

The properties of foam concrete made by one-step technology are noticeably inferior to the material produced by the classical technology. With a high density of the material, its strength characteristics were significantly lower, these foam blocks easily crumbled and pricked. Therefore, all serious manufacturers work precisely on the classical technology.

Also mention should be made of using autoclaves. Production of foam blocks refers to non-autoclaving technology. This does not mean at all that the autoclave cannot be used. Just the price of such equipment is large, and the difference in quality between foam blocks produced using and without the autoclave is insignificant.

What are good foam blocks

This material is now rapidly gaining popularity around the world, caused by a whole range of positive qualities.

Not for nothing in Western Europe such blocks are called bioblocks.

• Foam blocks are considered fully environmentally neutralmoreover, if the production is conducted using an organic-based foaming agent, then these blocks can be safely called environmentally friendly.
• This building material has an enviable durability., manufacturers give a guarantee of 80 years and above. The fact is that, like all concrete products, foam blocks only gain strength over time.
• A house made of foam blocks has extremely low thermal conductivity.. This is caused by the porous structure of the material, the size of air pores varies between 3 and 4 mm. In winter, such a house will be heated quickly and keep warm for a long time, and in summer it will be cool in it.
• The material does not emit any harmful vapors., even when exposed to high temperatures. In heavy concrete, the role of coarse filler is played by crushed stone, which may have an increased radiation background. Foam blocks are filled with air and are free from this drawback.
• The proportion of foam is quite lowthat is good not only during transportation, but also during the construction of houses. Structures of foam blocks do not require a powerful and expensive foundation.
• In the liquid state, the solution has good fluidity.that allows you to fill it in forms of any size and configuration. Therefore, the size of the foam used in private construction can be changed depending on the purpose.

Production of blocks at home

As mentioned earlier, foam blocks are made without autoclaving method, which makes it possible to do them yourself at home. In this case, the thickness of the foam concrete will be determined by the thickness of the wall of the erected structure. Plus, this solution can be poured screeds and various kinds of monolithic floors or partitions.

In private construction, D600 foam concrete is considered the most common.

The components here are classic, specifically you will need:

• About 200 kg of sifted quartz sand, it is desirable that it does not contain clay inclusions, as this will reduce the characteristics of the final product.
• Cement is taken brand M400 or higher, but the best in this case is Portland cement PTS500DO, it will need 320 kg.
• Frother enough 1 - 1.5 liters.
• Water can be used ordinary, low-acid water with low salt content.

Important: the cost of the final product is most dependent on cement. The price of cement in the general boiler takes about 75%, but you should not save on it, especially if foam concrete is made without adding sand.

Instructions for making the solution elementary simple. The main thing is to purchase special equipment. The two most important units are the foam generator and the concrete mixer.

The foam generator consists directly of the tank for beating the foaming mixture and the compressor for forcing air. Modern models are equipped with foam dispensers and automation for programming the process.

Concrete mixer is no less important unit, to do the usual concrete mixer here will not work. Foam and cement-sand mortar should be mixed quickly and efficiently. If you tighten the mixing process, even a very stable foam will begin to settle and the solution will be hopelessly flawed.

It is also desirable that this unit be equipped with a concrete pump, this will significantly speed up the work on filling out the forms and will be an additional advantage if you decide to pour a monolithic screed or partition.

As for the forms, their manufacture should be given special attention. Of course, you can make them out of wood or plywood, but wood absorbs water and therefore, we recommend using metal or plastic forms. It is better to make them collapsible, it will facilitate the process of releasing the foam block.

In our opinion, it is worth spending time on making molds with your own hands only if you need non-standard shape blocks. For the construction of typical buildings it is better to use blocks of standard sizes and it makes sense to buy a form. This industry is now developing rapidly, so you can easily buy a good second-hand form.

Tip: before pouring, the mold is smeared with a special compound or wrapped in polyethylene so that the block can easily come out. We do not recommend lubricating with oily liquids, because subsequently there may be a problem with the lining of such blocks.

On the video in this article you can find interesting trivia on this topic.

Conclusion

When buying factory foam blocks, pay attention to the certificate. There is a certain GOST for foam concrete, to be precise, GOST 25485-89 is a general rule regarding the regulation of the quality characteristics of all cellular types of concrete. If only TU is indicated, then there are doubts as these units.