Each person who is thinking about building his house is faced with a difficult choice - which material to use. It depends on how strong and reliable the structure will turn out. And I want the house to stand for centuries, if not even more! Currently, in the field of construction, gas silicate brick is gaining more and more popularity. But in addition to this, other options are also used - wood, ordinary brick, concrete blocks, including a variety of building technologies.
As for gas silicate, in recent years it is he who is preferred because of certain advantages. Affordable cost, excellent performance, quick construction and much more - this is not a complete list of all the advantages that porous building material has. Actually, this and much more will be discussed further.
What is gas silicate?
In fact, gas silicate is an artificial stone or one of the varieties of cellular concrete. What is characteristic, this building material can be made even in artisanal conditions. All that is needed is to mix all the components in a solution and leave to solidify in the fresh air. You can immediately understand how “high” the quality will turn out in the end.
However, high-quality brick and aerated concrete is obtained only in professional production, which can be carried out using an autoclave. As a result, under the influence of high temperature and a certain pressure, the concrete mixture hardens and the product is durable.
For this reason, the autoclave technique underlies the production of this building material in many factories when it comes to its production on an industrial scale. Moreover, the dimensions of the blocks fully comply with existing GOSTs.
Production
Many who decide to build their house using gas silicate blocks unwittingly think about what, in fact, they are made of.
For this, certain components are mixed, and the composition of gas silicate bricks looks like this:
- quicklime;
- Portland cement;
- fine sand or ground;
- water with aluminum powder;
- additives accelerating the hardening process.
While a solution is being prepared for gas blocks, a chemical reaction begins with the formation of hydrogen between aluminum powder, lime and water. It is due to the presence of this gas during subsequent solidification in concrete that small tight cavities are formed, and in a rather large amount.
The result is a twofold result - on the one hand, thanks to these voids, the weight of the blocks is noticeably lightened. However, there is a flip side to the coin - for the same reason, thermal conductivity decreases.
Autoclave and non-autoclave products
The manufacture of blocks in an autoclave from a technological point of view is a rather energy-intensive process. For this reason, the cost of such a building material is much higher. Gas silicate bricks are dried at a temperature of 175 ° C, the pressure is 0.8-1.2 MPa. And only large enterprises can afford it.
As for the non-autoclave method of manufacturing blocks, they freeze in the fresh air, in the absence of any external influences. And in general, such production is cheaper. At the same time, the technical characteristics of the material are noticeably inferior to those bricks that were produced using an autoclave.
Varieties of gas silicate
Before touching on the indisputable advantages, as well as a number of disadvantages (unfortunately, they are also present), we will familiarize ourselves with the main types of gas silicate material. Depending on the technology used in the production of gas silicate blocks, and on the ratio of components, they differ in density.
This characteristic is fundamental, which determines the scope of this material. As a rule, the density is indicated by the Latin letter D and varies in a rather wide range - from 200 to 1200 kg / m 3 . If we compare the gas silicate block with expanded clay concrete brick, then the latter is slightly higher (from 700 to 1500 kg / m 3 ).
Based on this parameter, gas silicate blocks can be divided into several groups (the density D is indicated in parentheses):
- Thermal insulation (D from 200 to 400).
- Heat-insulating and structural (D from 500 to 700).
- Structural (D from 800 and more).
Consider these varieties of cellular material in more detail.
Thermal insulation bricks
As we now know, it depends on the density where this or that gas silicate element is used. The heat-insulating type is relevant for the insulation of capital walls, including the construction of jumpers. It has a high degree of thermal conductivity, but its strength is not very good. For this reason, this option is not suitable for the construction of buildings above 1 floor.
During the use of gas silicate bricks of this variety for the construction of partitions, a non-cement-sand mixture is usually used. Stacking is done using special glue. As a result, the seam is as thin as possible. For this reason, in some cases, when erecting such partitions, additional cladding is not required.
Thermal insulation and constructional variety
The thermal insulation and structural blocks are already slightly stronger than the bricks described above. Nevertheless, even such material is unsuitable for the construction of buildings above 3 meters. Typically, they fit internal partitions or with their help, warming of the bearing walls of one-story buildings is performed.
Building blocks
These are the strongest bricks that can only be obtained with the technologies used. These blocks are just suitable for the construction of buildings on several floors. And the higher the marking, the stronger the material itself.
Dimensions
The dimensions of gas silicate brick, weight and a number of other technical characteristics are regulated by GOST 21520-89 and 31360-2007. These regulatory documents include general information regarding all types of cellular concrete.
As for the exact dimensions, the gas-silicate type of bricks is usually produced in larger dimensions than ceramic building briquettes. Actually due to this, the process of erecting buildings is much faster (4 times). Accordingly, the number of seams and joints is markedly reduced.
The standard block size is 600 × 200 × 300 mm, but there can also be half blocks with dimensions of 600 × 100 × 300 mm. But this is not the final size, there are others:
- 500 × 200 × 300 mm;
- 588 × 150 × 288 mm;
- 600 × 250 × 50 mm;
- 600 × 250 × 75 mm;
- 600 × 250 × 100 mm;
- 600 × 250 × 250 mm;
- 600 × 250 × 400 mm.
As you can see, there are boundaries that are usually not crossed. In other words, the height and width of the blocks should not exceed 500 mm, and the length - 625 mm. Nevertheless, manufacturers can produce aerated concrete bricks in accordance with the specifications. And in this case, the characteristics of gas silicate bricks (including dimensions) can be absolutely any.
For example, for partitions, the dimensions of the products are 100 x 250 x 600, while the external walls can be laid out with elements measuring 300 x 250 x 625.
Undoubted advantages
Now it’s worth talking about the clear advantages of gas silicate. One of the significant advantages of gas silicate blocks is its light weight. This is especially noticeable when compared with silicate brick. As a result, it is possible to profitably save on the time of erection of the building, and on the installation costs.
Other advantages include the following advantages:
- Environmental friendliness - walls built from gas silicate blocks are not able to release toxic substances into the atmosphere. And since the material for the most part consists of natural components, there is no threat to human life and health.
- Convenience - there are various not only sizes, but also the shapes of bricks. Actually due to this, you can erect walls of any complexity.
- Frost resistance and sound insulation - it was not for nothing that we considered the composition and use of gas silicate bricks, the presence of voids in the bricks just affects this, as mentioned above. It is due to the large number of "bubbles" and the air gap between the blocks that high frost resistance is ensured, equal to about 200 cycles (as manufacturers assure). And the sound insulation index is 50 dB.
- High degree of fire resistance - gas silicate blocks are able to withstand fire at the proper level for 7 hours. And again, this is due to the natural composition.
- Ease of processing - you can work with these bricks using the simplest standard tools. If there is a need to give a certain configuration of blocks to create architectural additions and decorations, then gas silicate is quite possible.
As you can understand, the presence of many of these advantages is due to the porous structure of the overall material. But what about the negative side? They are also present. Fortunately, there are not so many of them.
but on the other hand
Despite all the features of the use of gas silicate brick, this material has its drawbacks:
- Hygroscopicity. Due to the fact that moisture penetrates into open cells, walls can become cracked during temperature fluctuations. In winter, they generally freeze. Therefore, there is a need for finishing from siding with the inclusion of a ventilation gap in order to remove condensate.
- Frost resistance at a low level. Despite all the assurances of manufacturers, the real indicator does not exceed 20 cycles.
- High degree of shrinkage. Due to the low bending strength, cracks may appear on the surface of the blocks. To prevent destruction, a monolithic foundation is laid and reinforcing belts between floors are installed.
As for the absorption of moisture, then, having hit the surface of the gas silicate block, it is almost all in its internal part.
Everyone knows what can happen to such a “sponge” in the case of severe frosts - it will simply be torn to pieces.
Useful Tips
Many experience serious difficulties in terms of how it is better to lay gas silicate bricks during the construction of an outbuilding or residential building. Effective tips that will be given below will avoid many errors:
- Regardless of which main laying method was chosen (mortar or special glue), the first row should be fastened with a cement-sand mixture. This will increase the reliability of the entire masonry.
- Due to the hygroscopicity of gas silicate blocks, the mixture to be bonded must be thick. Otherwise, all moisture will be absorbed into the cellular structure of the material. How it can end in severe frosts, we now know.
- If necessary, all irregularities and roughness should be removed using a hand grater or surface grinder.
- It is imperative to periodically check the level of the entire masonry with the help of cargo or the rule.
- If the walls are accidentally stained during operation, the contaminants should be removed before they dry.
Upon completion of the work, it is necessary to treat all surfaces with a primer, moisture stop or any other waterproofing composition. It is better not to buy gas-silicate blocks that were in use, no matter how much they cost - no one will give guarantees regarding the storage conditions of the material.
Reviews of gas silicate bricks
The attitude of professional builders to the material in question is understandable, but what do ordinary consumers think about it - that is, we? And many have already managed to appreciate all its indisputable advantages on personal experience. And most of them note the presence of a number of advantages after the construction of houses, baths and outbuildings. Heat, comfort, air is not too dry, construction costs are significantly reduced - all this and much more is enclosed in gas silicate blocks.
Unfortunately, not without negative experience. However, there is a well-grounded explanation for this - often the whole point is in violation of the technology of erection of buildings. In particular, it is necessary to use material grades according to their scope, etc.
Otherwise, many are satisfied with the quality and reliability of gas silicate bricks. And thanks to its design features, the popularity of this material is only increasing every year.