Walls from foam concrete. technical characteristics of the

Among cellular concrete, foam concrete blocks for external walls are distinguished by at least one important advantage - it does not accumulate moisture, therefore, it can be left without additional lining using a hydraulic barrier.

Such materials are very convenient to use for low-rise construction at home - it is distinguished by the speed and convenience of laying, as well as easy processing such as cutting or drilling. Below we will talk about this in more detail, as well as show you the video in this article, as a supplement on the topic.

Acquaintance with foam concrete

Note. Foam concrete should not be confused with aerated concrete, despite the fact that they are very similar in structure and appearance. The first is made by adding foam-forming compositions to the solution and solidifies naturally, while the second is made in autoclaves. In addition, the autoclave material is able to accumulate moisture, while frozen naturally, has water-repellent properties.

Specifications

• Foam concrete, as a material can be used in the form of blocks for classical masonry in the construction of buildings of a different nature, in monolithic housing construction, as in the photo above, as well as a thermal and sound insulator for floors, walls and roofs.
• The insulating qualities of this material are quite high., although, of course, they should not be compared with such heaters as foam plastic or mineral wool. Nevertheless, air bubbles create good thermal protection, and in some cases building construction does not require additional insulation.
• Much less cement is used for the production of cellular blocks and monoliths than for ordinary concrete., which significantly reduces their cost. In addition, the structure made of such material has a smaller mass, therefore, in such cases, a massive foundation is not needed, which again affects the overall price of the whole structure.
• Foam concrete is environmentally friendly., and in terms of ease of processing it is compared to wood - it is also easy to saw, drill and nail, but, despite all the advantages, there are also disadvantages.
• Because of its porosity, a block or monolith has less mechanical strength than ordinary concrete or concrete goods.. In addition, the wall erected from such a material can not be called a good basis for hanging furniture, plumbing and heating appliances.

Strength and thermal conductivity table

Manufacturing

Foam-concrete blocks can be made by the method of dry mineralization (low-expansion foam is combined with dry components) and barotechnology (for this purpose, overpressure in the tank, achieved by air injection, is used). But the most reliable and, of course, the most used, can be called the classical method.

According to the classical method, the dough is made from the usual cement-sand mortar, to which specially prepared foam is added from the foam generator. In the concrete mixer, the solution is combined with the foam, as a result of which a foam concrete mix is ​​formed - with the subsequent setting and hardening, the finished foam concrete is obtained.

To obtain the monolith, Portland cement, water and foam are used, which is obtained as a result of the use of a synthetic or organic foaming agent. The resulting solution is poured into a permanent formwork, the thickness of which can be adjusted arbitrarily, depending on the need in each case.

Most often, this method is used in frame housing construction, but it is also thermal insulation of the roof and pipelines, screed ceilings and road construction.

Monolith property table

Строительство

Masonry dimensions

To determine the thickness of the walls of your future home, it is necessary to carry out strength and thermal calculations, and in this case we will use foam concrete with a density of D600 as the basis.

Предположим, что вам нужно возвести двухэтажное здание, тогда нагрузка на стены первого этажа при коробке 10×10м вместе с перекрытиями и стенами второго этажа будет порядка 15-18 тонн и в этих случаях каждые 100 мм стены по толщине в состоянии выдержать десятитонную нагрузку.

If you add to the general loads also all household items with which you fill the dwelling, a lot of snow on the roof and take into account possible masonry defects, then a wall thickness of 300 mm will be quite enough. But this applies only to mechanical loads and here we are not talking about heat saving.

If we go back to the table of strength and thermal conductivity, we will see that for D600 foam concrete, the thermal conductivity coefficient is 0.14 and in order to achieve a sufficient level of thermal insulation, we need to focus on the value R = 3.14.

As the instruction advises, we will use the formula R = d /?, Given that d is the design thickness of the wall, eh? - is the thermal conductivity of the material. Such resistance is calculated in cases where the air temperature in the building region reaches 40?

Masonry

When you were designing a house, you certainly took into account not only the box, but also the foundation on which it will be located, therefore, the thickness of the tape or grillage should not be narrower than the walls and partitions. It will be even much better if the foundation tape is a few centimeters wider than the wall - because the latter will also have an inner, and possibly an outer facial finish.

In addition, the basement of the building should be separated from the box with cut-off waterproofing, which will block the access of ground moisture, as well as serve as thermal insulation (even a warmed foundation can transmit cold to the walls).

Above the cut-off waterproofing, that is, for the first row of masonry, a cement-sand mortar should be used (with admixture of tile glue) with a thickness of 10-20 mm - this should serve as a basis for careful leveling of the first row, which will determine the evenness of the other higher rows.

Укладка блоков начинается с любого угла коробки и возводится не порядно, а вразлёт, то есть поднимается угол, где блоки ставятся в замок и от него постепенно отходят ряды кладки. Соединение может производиться при помощи специальной смеси типа » YTONG», либо универсальным плиточным клеем типа «Ceresit» с толщиной швов не более 5 мм.

When building a house, it should be taken into account that the integrity of the wall is influenced by stretching factors, which are shown in the upper image, therefore, GOST 5781-82 and GOST 10884-94 provide for horizontal reinforcement of the wall. If you follow all the rules, the reinforcement should be made on the first, and then, on every fourth row of the building, but, in the extreme case, when the height of the building does not exceed 3 m, then you need to reinforce the lower and upper rows.

In addition, metal rods should be laid at the top and bottom of window and door openings.

For reinforcement, wire rod or rod A-III is usually used, the cross section of which should not be less than 6 mm and not more than 10 mm. The armature fits into the grooves that you can do with your own hands - the foam concrete is processed quite well - their depth and width must be sufficient for the metal to close with the adhesive mixture. Otherwise, air and moisture may enter, causing rust.

Note. The processing of cellular concrete is done in the same way as diamond drilling of holes in concrete and cutting of reinforced concrete with diamond circles, only the process requires much less labor and there is no large wear of tools (drills, crowns and discs).

Conclusion

It is noteworthy that the total price for the construction of foam concrete is obtained much lower than from ordinary concrete and concrete products. And, although the strength of such material is lowered, the construction of buildings from blocks or monolith is quite justified and is currently experiencing a peak of popularity.