Every person who thinks about building his own house is faced with a difficult choice - what kind of material to use. It depends on how strong and reliable the structure will turn out. And so you want the house to stand for centuries, if not even more! Currently, gas silicate bricks are becoming increasingly popular in the construction industry. But besides this, other options are also used - wood, ordinary brick, concrete blocks, including various building construction technologies.
As for gas silicate, it has recently been given preference due to certain advantages. Affordable cost, excellent performance, quick construction and much more - this is not a complete list of all the advantages that a porous building material has. Actually, this and many other things will be discussed further.
What is gas silicate?
Basically,gas silicate is an artificial stone or one of the varieties of cellular concrete. Tellingly, this building material can be made even in artisanal conditions. All that is needed is to mix all the components into a solution and leave to harden in the fresh air. You can immediately understand how “high” the quality will be in the end.
However, high-quality bricks and aerated concrete are 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 is at the core of this building material in many factories when it comes to commercial production. At the same time, the dimensions of the blocks fully comply with the existing GOSTs.
Production
Many who decide to build their house using gas silicate blocks involuntarily wonder 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 that accelerate the hardening process.
While the solution for gas blocks is being prepared, a chemical reaction begins between aluminum powder, lime and water to form hydrogen. Exactlydue to the presence of this gas, during subsequent solidification, small sealed cavities are formed in the concrete, and in a fairly large amount.
The result is a double result - on the one hand, thanks to these voids, the weight of the blocks is noticeably lighter. However, there is also the other side of the coin - for the same reason, thermal conductivity decreases.
Autoclaved and non-autoclaved items
Production 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 making blocks, they harden in the fresh air, in the absence of any external influence. 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 undeniable advantages, as well as a number of disadvantages (unfortunately, they are also present), let's get acquainted 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 from each other.
This characteristic is fundamental, which determines the scopeapplication of this material. As a rule, the density is denoted by the Latin letter D and varies in a fairly wide range - from 200 to 1200 kg/m3. If we compare the gas silicate block with expanded clay concrete brick, then the latter has a slightly higher value (from 700 to 1500 kg/m3).
Based on this parameter, gas silicate blocks can be divided into several groups (density D is indicated in brackets):
- Heat-insulating (D from 200 to 400).
- Heat-insulating structural (D from 500 to 700).
- Structural (D 800 or more).
Let's consider these types of cellular material in more detail.
Insulating bricks
As we now know, it depends on the density where exactly this or that gas silicate element is used. The heat-insulating type is relevant for the insulation of main walls, including the construction of lintels. It has a high degree of thermal conductivity, but the strength is not very good. For this reason, this option is not suitable for building a building 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. Laying is carried out with a 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.
Heat-insulating structural variety
In heat-insulating structural blocks, the strength is already somewhat greater than that of bricks,described above. Nevertheless, even such material is unsuitable for the construction of buildings above 3 meters. Usually they fit internal partitions or use them to insulate the load-bearing walls of one-story buildings.
Construction blocks
These are the strongest bricks that can only be obtained using the technologies used. These blocks are just right for the construction of buildings with several floors. And the higher the marking, the stronger the material itself.
Dimensions
The dimensions of gas silicate bricks, weight and a number of other technical characteristics are regulated by GOST 21520-89 and 31360-2007. These regulations 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 carried out much faster (4 times). Accordingly, the number of seams and connections is noticeably reduced.
Standard block size is 600 x 200 x 300 mm, but semi-blocks with dimensions of 600 x 100 x 300 mm can also be available. But these are not the final sizes yet, there are others:
- 500 × 200 ×300mm;
- 588 × 150 × 288mm;
- 600 × 250 × 50mm;
- 600 × 250 × 75mm;
- 600 × 250 × 100mm;
- 600 × 250 × 250mm;
- 600 × 250 × 400 mm.
As you can see, there are boundaries beyond whichstep over. 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 specifications. And in this case, the characteristics of gas silicate bricks (including dimensions) can be absolutely anything.
For example, for partitions, the dimensions of the products are 100 x 250 x 600, while external walls can be laid out with elements of 300 x 250 x 625.
Undoubted advantages
Now it's worth talking about the clear benefits of gas silicate. One of the significant advantages of gas silicate blocks is their light weight. This is especially noticeable when compared with silicate bricks. As a result, you can profitably save both on the construction time of the building and on installation costs.
Other advantages include the following:
- Environmental friendliness - walls built from gas silicate blocks are not capable of releasing 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 he alth.
- Convenience - there are not only different sizes, but also shapes of bricks. Actually, due to this, walls of any complexity can be erected.
- 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 bricks, as mentioned above, just affects here. It is due to the large number of "bubbles" and the air gap between the blocks thathigh frost resistance, 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 the effects of fire within 7 hours at the proper level. And again, this is due to the natural composition.
- Easy to work with - these bricks can be worked with the simplest standard tools. If there is a need to give a certain configuration of blocks to create architectural additions and decorations, then this is quite possible with gas silicate.
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 downsides? They are also present. Luckily, there aren't too many of them.
Reverse side of the coin
Despite all the features of the use of gas silicate bricks, this material has its drawbacks:
- Hygroscopicity. Due to the fact that moisture penetrates into open cells, with temperature fluctuations, the walls can become cracked. In winter, they generally freeze through. Therefore, it becomes necessary to finish the siding with the inclusion of a ventilation gap to remove condensate.
- Frost resistance is low. Despite all the manufacturers' assurances, the real figure 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 are installed betweenfloors.
As for the absorption of moisture, then, once on the surface of the gas silicate block, it is almost all in its inner part.
Everyone guesses what can happen to such a "sponge" in case of severe frosts - it will simply be torn apart.
Helpful tips
Many are experiencing serious difficulties in terms of how exactly it is better to lay gas silicate bricks when building any outbuilding or residential building. The actionable tips below will help you avoid many mistakes:
- Regardless of which main laying method was chosen (mortar or special glue), the first row must 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 bonded mixture must be thick. Otherwise, all moisture will be absorbed into the cellular structure of the material. How this 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 mandatory to periodically check the level of all masonry using a weight or rule.
- If the walls are accidentally soiled during the work, the dirt should be removed before they dry.
After completion of work, it is necessary to treat all surfaces with a moisture stop primer orany other waterproofing composition. It is better not to buy used gas silicate blocks, no matter how much they cost - no one will give guarantees regarding the storage conditions of the material.
Reviews on 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, you and I? And many have already managed to appreciate all its undeniable advantages from personal experience. And most of them note the presence of a number of advantages after the construction of houses, baths and outbuildings. Warmth, comfort, air is not too dry, construction costs are significantly reduced - all this and much more is contained in gas silicate blocks.
Unfortunately, not without negative experience. However, there is a well-founded explanation for this - often the whole thing is in violation of the construction technology of buildings. In particular, it is necessary to use material grades according to their application, 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 only increases every year.
