Aerated concrete is one of the types cellular concrete, an artificial stone consisting of 85% air. Due to its good ability to retain heat, low weight, ease of cutting and processing, and relatively affordable price, it is often used in individual and professional construction of houses and other buildings. Large blocks are made from it, which are convenient for laying out walls due to its low mass.
The density indicator is determined by marking:
- D350 - 350 kg/m3, used only as insulation;
- D400 - 400 kg/m3, for filling openings;
- D500 - 500 kg/m3, for one-story houses;
- D600 - 600 kg/m3, for masonry of two-three-story buildings, such as additional material in multi-storey construction.
The higher the grade, the better the strength, but the lower the thermal insulation properties. Wall elements, partitions, and lintels are distinguished by size. For load-bearing structures, options no lower than D400 are used.
They are made in two ways: autoclave and natural drying. outdoors. If you have a choice, then preference should be given to the first option - the autoclaved one is stronger (about such blocks of the INSI brand).
Advantages of aerated concrete houses
Advantages of gas blocks:
1. relatively low price;
2. savings on heating costs, houses made of aerated blocks require less energy for heating in the winter;
3. low load on the foundation, but high strength is required to prevent shrinkage;
4. optimal for individual construction houses, outbuildings, bathhouses “strength-lightness” ratio;
5. one person can lay out the walls from aerated concrete;
6. convenient transportation due to the low weight of the blocks;
7. minimal background radiation;
8. the ability to make various bends, arched openings, stairs and other structures of any, including complex configurations;
9. good level soundproofing;
10. ease of processing without the use of special equipment, aerated concrete blocks are easy to cut, saw, and grind with hand tools;
11. biological stability, fungi, mold, etc. do not appear on the surface;
12. vapor permeability, walls “breathe”;
13. fire resistance, aerated concrete does not support combustion, withstands temperatures up to +1200C, and during a fire it is almost not destroyed within 3 hours;
14. houses are easy to repair and rebuild.
Disadvantages of buildings made of aerated blocks
1. unsuitability for multi-storey construction as the main material of load-bearing walls due to low compressive strength;
2. a house made of aerated concrete warms up quickly (in 2 hours from 0 to 20C), but just as quickly gives off heat in the absence of heating (by 1C per hour);
3. even with minor violations of technology when pouring the foundation, causing shrinkage, up to 20% of the blocks become covered with cracks, this does not lead to the destruction of the house, but has a bad effect on the appearance;
4. the foundation must be stable with respect to any ground movements, otherwise the problem of cracks will arise again;
5. aerated concrete masonry with glue must be done very well, otherwise the house will be “blown out”;
6. the material is hygroscopic, quickly absorbs moisture from the air, including during fog, which forces the walls to be finished immediately after completion of the masonry, and be sure to waterproof and insulate;
7. The gas block has low frost resistance - only up to 35 defrosting-freezing cycles;
8. restrictions on finishing materials for facades;
9. before plastering, careful preparation of the walls is required, since their surface is too smooth, which is why it is very low level adhesion to any coating, it is necessary to use a special primer;
10. lime contained in aerated concrete and adhesive mixtures for it quickly renders any metal objects, including communication pipes in contact with the blocks;
11. gas blocks do not hold well to any type of fasteners (under shelves, wall cabinets, etc.), special fasteners are required (for example, plastic butterfly dowels, anchors);
12. low burglary resistance, thieves can simply cut out a passage with a chainsaw, and the bars on the windows hold up worse than those of houses made of other materials.
When comparing the advantages and disadvantages of a house made of aerated concrete, you need to pay attention to the fact that most of the disadvantages are eliminated during the installation process. To do this, you just need to carefully follow the technology and take into account all the nuances.
Owner reviews
“A year ago I finished building my house from aerated concrete blocks. The walls “breathe” and retain heat in the room perfectly. Laying is simple and quick. Several people can build in half a month cottage. The elements have impressive dimensions, but weigh little. It is possible to carry them alone. While using the house, I did not find any serious problems. In frosty weather it is warm and cozy. It took a little money, the advantages are to build cheaply and quickly. The disadvantage is fragility; it is necessary to pay utmost attention to the foundation, to exclude the possibility of any ground movements, and to reduce the effects of shrinkage. Otherwise, cracks cannot be avoided.”
Alexey, Irkutsk.
“Due to the low price between aerated concrete and brick, we chose the first option for building the house. In the process it became clear that heavy expenses for the installation of good vapor barrier and finishing. As a result, the house turned out to be relatively expensive, but still much cheaper than one made of brick. We haven’t noticed any significant shortcomings yet, but we’ve only been using the cottage for three years.”
Peter, Moscow.
“I built a house from aerated concrete myself. It is fragile, so I had to spend more time and money on the foundation than I expected. I posted it quickly and without any problems. It was only at the final finishing stage that I had difficulties. Special fasteners were expensive, plus insulation costs. Advantages: the walls are dry, the blocks are light in weight. Cons: the material is fragile, there is a lot of work on steam and heat insulation and associated financial costs.”
Ilya, St. Petersburg.
“I have a cottage made of gas blocks. To build the first floor I used D500, the second floor was laid out with D400. To increase the strength, an armored belt was installed under the ceiling. On the outside I applied vapor-permeable plaster. The result is a warm, comfortable home, but there is a drawback. It’s only warm while it’s heated; after turning off the heating devices it cools down quickly.”
Vasily, Krasnoyarsk.
“I chose aerated blocks as a material for a country house primarily because of the low price. In one summer he built a two-story house himself. It is necessary to additionally insulate it. The disadvantage of aerated concrete is that it strongly absorbs moisture due to its porosity. With the onset of winter, the water freezes and it begins to crack. I solved this problem by insulating the walls with polystyrene foam. The cost of heating a house is much less than that of our neighbors for a brick house, but ours is much warmer. Advantage: quick and easy to build. I recommend purchasing from reliable stores from trusted manufacturers. I bought two cubes very cheaply, but they started to crumble, so I had to buy more.”
Dmitry, Moscow region.
Gas silicate block is a fairly new “representative” of the construction industry, it became known not so long ago, but has already been able to establish itself as an inexpensive, “people’s” building material that can be used in the construction of any construction project.
It’s a pity, but, alas, the perfect building material has not yet been invented. Any of the existing building materials has both positive and negative indicators. We propose to dwell on the main advantages and disadvantages of these blocks, without trying to present them in a better light.
Advantages gas silicate blocks
- Thermal and sound insulation. They occupy first place among materials with low thermal conductivity and low sound transmission. This is due to the presence of a bubble structure in their structure. After all, it is a known fact that air is one of the strongest heat retainers. Indeed, as the number of bubbles (density) increases, the thermal insulation of the material increases.
- Durability. This material is not of interest to rodents, which cannot be said, for example, about wood and various types of bricks. In this regard, walls made of gas silicate are not afraid of destruction caused by these animals.
- Environmental friendliness. Gas silicate blocks environmentally friendly. They do not contain dangerous chemical components. Walls made from them do not pose a danger to the health of residents. In addition, the construction of houses from this material does not cause much harm to the environment when compared, for example, with wood, for which forests are cut down.
- Low cost. Building houses from this material is cheaper than using wood or brick. The solution for creating a block has a fairly simple composition and is unpretentious to work with. Accordingly, the price of the resulting product is very reasonable.
- Ease of processing. Gas silicate blocks lend themselves well to cutting and, in some cases, drilling due to their light porous composition. The process of building the wall itself is also not difficult. The blocks, although voluminous, are not heavy. Therefore, the raising of the walls is quite intensive and with minimal labor costs.
- Low weight. Since a gas silicate block has a porous composition, it is much lighter in weight than, for example, a brick. Despite this, builders do not advise saving too much on laying the foundation, believing that the process can actually be made quite cheap. A gas silicate block requires a reliable strip base to ensure optimal foundation of the walls.
Flaws gas silicate blocks
- Fragility. The inside of the block is not too dense, the reason for this is the porosity of the composition and the presence of air bubbles. These units should be transported, moved and used very carefully. Alas, even a minimal blow can split the block, cracks form and the material becomes unsuitable for construction. In addition, builders advise using a reinforced concrete belt as insurance, which will provide additional durability.
- Low-rise construction. Gas silicate blocks are afraid of heavy loads. For this reason, this material is not used in the construction of multi-story buildings. The building should be no higher than 1-2 floors.
- Fear of moisture. One of the significant disadvantages of the material is moisture resistance. Because of it, the gas silicate block loses its strength characteristics and collapses. In this regard, block walls must be finished inside and outside. The optimal method is plastering using heat-insulating material.
- Building restrictions. It is impossible to build from this building material, for example, a bathhouse, sauna, etc. This is due to the fact that the material is afraid of increased moisture. In this case, it is more appropriate to use brick.
- Shrinkage. Walls made of this material may shrink after some time. As a rule, shrinkage appears 20-25 days from the moment the wall is built. Until this point, the wall should not be plastered. This is due to the fact that if Finishing work carried out directly after installing the blocks, splits and ruptures may occur as a result of shrinkage.
Gas silicate blocks are...
As you know, a gas silicate block is essentially foamed concrete, the structure of which resembles cells. The production of this block in the industrial sphere is carried out in a special autoclave oven, where cement, sand, lime and aluminum chips are mixed, after which the mixture hardens at a certain temperature and pressure. By the way, it is pressure that plays the main role in obtaining a strong and dense structure of a given block.
From the above it is clear that gas silicate blocks, despite all the disadvantages, have a huge number of undeniable advantages. All material shortcomings can be easily eliminated by using the latest materials used in finishing. Thanks to gas silicate blocks, it becomes possible to build a warm, reliable and strong house at a very attractive price!
Gas silicate blocks have become increasingly popular as a material for the construction of houses and other premises. This is mainly due to the very favorable ratio between the price of building materials and its characteristics.
In fact, gas silicate is one of the types of aerated concrete (autoclaved cellular concrete). It is used in the construction of buildings and structures for almost any purpose and comes in two types: wall and partition. They differ from each other in that the wall one can withstand higher loads, but its cost is also slightly higher. is carried out much faster than when using more traditional materials such as brick or cinder block.
History of the material and manufacturing technology
At the end of the 19th century, the need for a multifunctional material arose. At the beginning of the last century, some inventors received a material that was patented as “miracle concrete”. Under this name was hidden the progenitor of modern aerated concrete, but its characteristics did not reach modern ones at all.
In the form in which they are known, aerated concrete blocks appeared already in last decade 20th century. According to the manufacturing method, they are divided into autoclave and non-autoclave. The latter type is characterized by heterogeneity and the presence of harmful pores, which over time cause significant shrinkage.
Autoclave, on the contrary, is much more environmentally friendly and almost twice as strong. The components for preparing autoclaved aerated concrete are lime, sand, water, cement, gypsum stone. After mixing these materials, a small amount of aluminum powder is added to the resulting mass, which promotes the formation of gas bubbles, ensuring the porosity of the gas silicate blocks. After swelling of the material occurs, it is necessary to hold it for a while. It is then cut and placed in an autoclave where it finally hardens. This technology is unique in that it does not leave any waste during production and is absolutely safe for the environment.
Advantages of gas silicate blocks
This construction material has many advantages over its more traditional competitors. Among them are the following:
- Light weight. It is almost five times lighter than conventional concrete, which makes it possible to save on the transportation and installation procedure. In addition, low weight significantly reduces the labor intensity of work.
- Good strength indicators. For example, gas silicate with a density of 0.5 t/m 3 has very high compressive strength. This allows it to be used in buildings that are load-bearing in low-rise buildings. It can also be used as filler in frame buildings and for constructing interior walls and partitions indoors.
- Excellent thermal insulation properties. According to this indicator, it is three times higher than ceramic brick and 8 times - heavy concrete. This allows you to save a significant amount on the thermal insulation of the building.
- Ability to accumulate heat. Gas silicate blocks can accumulate significant amount heat, the source of which can be both the heating system and the sun's rays. Thus, in the standard masonry of these blocks (375 mm), an amount of heat accumulates equivalent to that accumulated in brickwork, thickness 600 mm. This ability allows you to save a significant amount of energy on heating during the cold season.
- Sound insulation is 10 times better than brick. The porous structure allows you to absorb sounds very effectively, maintaining a comfortable atmosphere in the room.
- Able to withstand flame exposure for several hours.
- The use of only natural ingredients ensures complete safety from an environmental point of view.
- Thanks to their structure, they have the ability to “breathe”, creating an excellent indoor microclimate.
- Minimal deviations in the dimensions of gas silicate blocks facilitate the process and masonry and reduce construction time.
Disadvantages of gas silicate blocks
But as you know, nothing is perfect. This also applies to gas silicate. It has the following disadvantages:
- Relatively low strength and frost resistance. Walls made of this material tend to crumble under mechanical stress. It is not easy to hang any furniture elements on them, because the plastic dowels will simply crumble the gas silicate.
Foreman's advice: if you need to hang something on the wall, you must use special ones that do not destroy the material.
- High hygroscopicity (tendency to absorb moisture). In theory, gas silicate, like a sponge, can absorb huge amounts of water, after which fungus can form in the pores. Therefore, it is necessary to reliably protect it from contact with moisture.
- Over time it may shrink significantly. This will cause the wall to crack.
Foreman's advice: to avoid shrinkage, when laying a wall, it is necessary to lay reinforced mesh or metal rods every 3-4 rows.
Despite all the disadvantages of gas silicate blocks, the advantages still largely compensate for them. If all the rules for their laying are strictly observed, houses made of this material will last a very long time and will reliably serve their owners.
Video
Manufacturers of such building finishing claim that buildings based on gas silicate can be compared with wooden buildings in terms of microclimate. At the same time, the construction procedure is not particularly complicated or labor-intensive, so all work can be completed without the involvement of specialists and in a short time.
This material is able to guarantee an acceptable rate of heat and air exchange, this is possible due to the porous surface of the gas silicate. It’s quite warm inside the building during cold weather, but waterproofing will be necessary to maintain the temperature. To ensure that the surface can breathe, you will need to cover it using foam plastic.
The simplicity of construction procedures depends on the geometry of the material. If the blocks are smooth, then erecting the building is quite easy. During the construction process you will need to use special glue. The use of a cement mixture will result in the formation of large joints. Because of this, the thermal conductivity and strength of the surface will be significantly reduced. Due to the heaviness of the blocks, it will be quite difficult to do the work yourself; you will need help.
During construction you will need to take into account a number of the following nuances:
- This material is ideal for the construction of 2-story buildings, but no more. If the load on the blocks is too great, the material may not withstand and collapse.
- After constructing the first floor of the house, it is necessary to perform monolithic belt strapping. Only this will allow the weight of the second floor and roof to be evenly distributed to the lower levels. The 3rd row of finishing will need to be reinforced using a mesh based on metal or sheets.
- Monolithic strip foundations must be used as the basis for such substrings, so it will not be possible to save money during the construction process.
- The constructed walls shrink over the course of a year. This nuance must be taken into account when planning internal surface cladding. Due to shrinkage, plaster can quickly crack, so it is preferable to use drywall.
Comparative characteristics of the parameters of aerated concrete and gas silicate
The comparative assessment of porous building materials is influenced by:
- moisture absorption (hydrophilicity);
- frost resistance (expressed by the number of freezing-thawing cycles);
- density;
- thermal conductivity;
- compressive strength (mechanical strength);
- vapor permeability;
- masonry thickness.
The average values for each parameter are shown in the following table:
What is gas silicate concrete
Gas silicate belongs to the group of cellular (foamed) concrete (SN 277-80) and is a wall block intended for the construction of enclosing structures (except for foundations).
The simplest type of gas silicate block - without grooves and ridges
Made from a mixture of:
- binder (Portland cement according to GOST 10178-76, calcium lime (according to GOST 9179-77);
- silicate or siliceous filler (quartz sand, fly ash, etc.);
- technical water;
- gas-forming additives (aluminum powder and others).
This composition ensures an active chemical reaction, which results in the formation of a large amount of hydrogen. It foams the concrete mass and after curing, a highly porous material with high thermal insulation properties is obtained.
Wall aerated blocks are produced in two ways:
- usual, that is, the composition hardens in shape under natural conditions and dries for 2-4 weeks. The finished product is inexpensive, but not very durable. The shrinkage coefficient is 2-4 times higher than that of the factory one;
- autoclave (GOST 31360-2007). The blocks are subjected to heat and moisture treatment (steaming) in special units - autoclaves. The steam pressure is maintained at 9 bar, temperature – up to +175 °C.
In the second case, the products are distinguished by an increased level of strength and density, and to impart special characteristics, various additives are used or the basic recipe is changed.
For example, for the production of gas silicate blocks with an increased level of frost resistance, Portland cement marked F50 and higher is used. Below watch video tips on building a house from gas silicate:
Gas silicate blocks: pros and cons of the material
Products made from gas silicate have a complex of serious advantages. The main advantages of gas silicate blocks:
- reduced mass with increased volumes. The density of gas silicate material is 3 times less compared to brick and about 5 times lower when compared to concrete;
- increased safety margin to withstand compressive loads. The strength indicator for a gas silicate block marked D500 is 0.04 t/cm³;
- increased thermal insulation properties. The material successfully competes with annealed brick, the thermal conductivity of which is three times higher than that of gas silicate;
- correct shape of blocks. Thanks to reduced tolerances on overall dimensions and clear geometry, blocks are laid on thin layer adhesive solution;
- increased dimensions. The use of large-sized silicate blocks with low weight for the construction of building walls allows to reduce the duration of construction;
- good workability. If necessary, it is easy to give the gas silicate block a given shape or cut the block material into separate pieces;
- acceptable price. Using block gas silicate for the construction of a cottage, private house or cottage, it is easy to significantly reduce the estimated cost of construction activities;
- fire safety. The blocks do not ignite when heated and exposed to open fire. They belong to low-flammable building materials included in the G1 flammability group;
- high soundproofing properties. They are provided due to the porous structure. The ability of blocks to absorb external noise is ten times greater than that of ceramic bricks;
- environmental friendliness. In the production of the gas silicate mixture, no toxic ingredients are used and no components harmful to health are released during operation;
- vapor permeability. Through the air cells located inside the gas silicate mass, air exchange occurs, creating a favorable microclimate inside the building;
- frost resistance. Gas silicate blocks retain the structure of the massif and operational characteristics, withstanding more than two hundred cycles of prolonged freezing followed by thawing;
- heat storage properties. Gas silicate blocks are an energy-saving material that can accumulate thermal energy and gradually release it to increase the room temperature.
Application area depends on material density
Despite many advantages, gas silicate blocks have weaknesses. The main disadvantages of the material:
- increased hygroscopicity. Porous gas silicate blocks gradually absorb moisture through an unprotected surface, which destroys the structure and reduces strength;
- the need to use special fasteners for fixing hanging furniture and equipment. Standard fasteners do not provide reliable fixation due to the cellular structure of the blocks;
- insufficiently high mechanical strength. Block material crumbles under load, so it requires careful handling during transportation and laying;
- the formation of mold and the development of fungal colonies inside and on the surface of the blocks. Due to increased moisture absorption, favorable conditions are created for the growth of microorganisms;
- increased shrinkage amount. In real operating conditions, under the influence of loads, the blocks gradually shrink, which after some time causes the formation of cracks;
- reduced adhesion with sand-cement plasters. It is necessary to use special finishing compounds for plastering gas silicate.
Despite the existing disadvantages, gas silicate blocks are actively used for the construction of capital walls in the region low-rise construction, as well as for the construction of thermally insulated walls multi-storey buildings and for thermal insulation of various structures. Professional builders and private developers prefer gas silicate blocks due to the significant advantages of the material.
Photos of houses
Aerated concrete blocks retain heat well in the cottage, but only as long as they remain dry. If gas silicate walls on the facade are not reliably protected from precipitation, then they will not last long. In terms of cost, this building material outperforms many analogues. However, in the general estimate for the construction of such a building, it is necessary to take into account the obligation to complete its façade finishing.
For houses that are planned to be built from gas silicate blocks, there is no need to make an expensive and powerful foundation. This building material does not weigh that much. However, the foundation for masonry from it must have a grillage or be strip. The slightest distortion will inevitably lead to the appearance of cracks in the enclosing structures of their aerated concrete.
Gas silicate is inferior to brick in strength, but benefits in terms of thermal efficiency and less load on the foundation. The foam concrete analogue, with equal density, will also win in the matter of heat preservation. However, aerated concrete is much inferior to both of them in terms of moisture absorption. You need to choose this material thoughtfully, having first weighed all the pros and cons. It will take more money to finish and waterproof a home than for a brick or wooden building.
View of a block house
Unusual house geometry
House "under the roof" made of blocks
This is what walls made of high-quality gas silicate with the correct geometry look like
Plastered walls of gas silicate blocks
It is better not to leave the blocks open during the winter.
Construction of walls from gas silicate blocks
From such blocks you can make an unusual geometry of the house
House with a turret
Partition gas silicate blocks were used above the window spaces
Openings and niches can be easily cut with a hacksaw
In this example, the house is made with narrow windows
You can also try making semicircular walls
Gas silicate house with wooden floors
Most often, such walls are faced with brick.
Read also about other wall materials:
Read about other materials for the home:
Gas silicate blocks: sizes, pros and cons
5 (100%) 1 vote
General characteristics
The distribution of pores in aerated silicate is more uniform than in aerated concrete, therefore its strength and thermal insulation properties are somewhat higher. Weight aerated concrete block larger, so its masonry is more difficult and requires a more powerful foundation. Autoclaved concrete has precise geometry, therefore it is considered more economical due to the reduction in the consumption of masonry adhesive and finishing materials. Gas silicate masonry The walls turn out smoother and are easier and faster to build.
The thermal insulation of gas silicate is superior. In frost resistance it is inferior to aerated concrete, since the latter has a lower degree of water absorption. Due to the fact that it allows water to pass through without absorbing it, a favorable microclimate is created in the house. Gas silicate, on the contrary, is able to absorb moisture, from which it gradually begins to deteriorate.
The white color of gas silicate blocks looks aesthetically pleasing, so the walls do not need additional decorative finishing. The fire resistance of aerated concrete is higher, although it is inferior in noise insulation to gas silicate. The durability of both materials is difficult to assess, since they began to be used relatively recently. When purchased, one volume of aerated silicate blocks will cost more than aerated concrete, which is due to more complex manufacturing technology. Although the cost of the masonry itself from both materials is almost the same.
General characteristics of the gas silicate block
Gas silicate is considered an improved analogue of aerated concrete. The production technology for its manufacture includes the following components:
- high quality Portland cement, which contains more than 50 percent of the inorganic compound calcium silicate;
- water;
- aluminum powder as a blowing agent;
- slaked lime, enriched by 70 percent with oxides of magnesium and calcium;
- quartz fine sand.
A mixture of such components produces a high-quality porous material with good technical characteristics:
- Optimal thermal conductivity. This indicator depends on the quality of the material and its density. The D700 brand of gas silicate blocks has a thermal conductivity of 0.18 W/m°C. This figure is slightly higher than many values for other building materials, including reinforced concrete.
- Frost resistance. Gas silicate blocks with a density of 600 kg/m³ can withstand more than 50 cycles of freezing and thawing. Some new brands have a declared frost resistance of up to 100 cycles.
- Density of the material. This value varies depending on the type of gas silicate - from D400 to D700.
- Ability to absorb sounds. The noise insulation properties of cellular blocks are equal to a coefficient of 0.2 at a sound frequency of 1000 Hz.
Gas silicate blocks are considered an improved analogue of aerated concrete
Many technical specifications gas silicate are several times higher than the characteristic indicators of brick. To ensure optimal thermal conductivity, walls are laid out 50 centimeters thick. To create such conditions from brick, a masonry size of 2 meters is required.
The quality and properties of gas silicate depend on the ratio of the components used for its preparation. The strength of products can be increased by increasing the dose of the cement mixture, but at the same time the porosity of the material will decrease, which will affect its other technical characteristics.
Composition and production technology of gas silicate blocks
Composition of aerated concrete
Aerated concrete belongs to the class of lightweight cellular concrete. This material is a mixture consisting of 3 main components: cement, water and fillers. Lime and quartz sand. We should also talk about the additives that give aerated concrete its individual characteristics. Fine aluminum powder acts as an additive. All these components are thoroughly mixed, and under certain conditions, foaming of all these materials occurs. When aluminum powder reacts with lime, hydrogen is released. The huge number of hydrogen bubbles released makes up the porous structure, which is the main distinguishing feature of aerated concrete. Its structure resembles a concrete “sponge”, since the entire volume of the block consists of cells (bubbles with a diameter of 1-3 mm).
Gas silicate blocks
Gas silicate production technology
The cellular structure makes up almost 85% of the volume of the entire block, so this material is very light in weight. First, a mixture of components is prepared in a special mixer for 5 minutes, which includes Portland cement, fine sand (quartz), water, lime and a gasifier (most often, this is an aluminum suspension). Hydrogen produced by the reaction between aluminum paste (powder) and lime forms pores. Bubbles ranging in size from 0.6 to 3 mm are evenly distributed throughout the material.
Basic fluids flow in metal containers or molds. chemical reactions. The mixture is subjected to vibration, which promotes swelling and setting. After hardening, all surface irregularities are removed with a steel string. The formation is divided into blocks, and then they are sent to an autoclave unit. The final calibration of the finished blocks is carried out by a milling machine.
There are two methods for producing aerated concrete blocks:
Autoclave processing
This stage significantly improves the technical characteristics of gas silicate. Here, steam treatment is carried out for 12 hours at high pressure, the temperature of which is almost 200°C. This heating process makes the texture more uniform, thereby improving the strength properties (at least 28 kgf/m²). His thermal conductivity is 0.09-0.18 W (m∙K), which makes it possible to erect walls in one row (400 cm) in almost any climatic conditions, but excluding the northern regions.
Non-autoclave technology
It consists in the natural hardening of the mixture: moistening and drying under natural conditions. In this case, it is quite possible to do it yourself, since no special equipment is required. The strength of blocks in such production does not exceed 12 kgf/m².
Properties of autoclaved and non-autoclaved gas silicate
The first type is more expensive. This is due to significant manufacturing costs, as well as the best technical characteristics of gas silicate blocks produced by this method. They are much stronger, their thermal conductivity coefficient is lower. The pores inside such aerated concrete are distributed extremely evenly, which affects the precise compliance of the material with the given parameters.
Before you buy aerated concrete, you need to inquire about what kind of treatment it was made with.
Features of gas silicate
If we analyze the opinions different people about this artificial stone, they are often directly opposite. In addition, for the most part, they are subjective, since everyone involuntarily “tryes it on for themselves.” Even builders’ reviews of gas silicate blocks sometimes vary greatly. What characteristics and properties of the stone can be identified?
Advantages:
1. The strength of gas silicate blocks is quite sufficient to build a house of 1 - 2 floors without additional reinforcement of the structure.
2. In most cases, surface finishing is not required. Smooth edges of stones, their white color - often this is enough. But only if climatic conditions do not dictate the need for cladding the house.
3. High laying speed. If you have at least minimal experience, 1 m2 of wall takes no more than ⅓ hour.
4. The calibrated dimensions and weight of gas silicate blocks greatly simplify the construction process. Firstly, you can use a trailer to your personal car to transport them. Secondly, during installation you will not need to deal with precise fitting, especially cutting gas silicate. The smooth edges of the blocks, if they are sized, make their laying easier. Thirdly, the low weight allows all the work to be done manually, without the use of lifting equipment.
5. Low thermal conductivity of the stone. Reviews indicate that if you correctly determine the size of the blocks, this allows you to save not only on insulation material, but also on heating the house.
6. Affordable price gas silicate. Depending on the density and geometry, purchasing 1 “cube” will cost from 2,450 to 3,200 rubles.
Flaws:
Judging by the negative reviews, including from professionals, there are not so many of them.
- Insufficient bending strength. For this stone, taking into account the light weight of the samples, the most acceptable base option is a shallow tape. Or a pile-grillage foundation. In any case, if it is installed correctly, you can save a lot of money when building a house. Therefore, negative reviews on this item are somewhat relative.
- Gas silicate absorbs moisture. This is much more significant. However, according to reviews from residents of houses from GS, this problem is also solvable. For example, impregnation with special/means, external finishing. There are many options, and the choice of a particular one depends only on local conditions.
- Construction of residential buildings no more than 2 floors. Otherwise you will have to strengthen the structure. Plus to this is to build a strong foundation. The result is increased costs and the loss of such an advantage of gas silicate as the budget price of work.
- Construction of outbuildings - sheds, garages, workshops.
- Arrangement of partitions.
Price
| Dimensions, mm | Cost, rub/m3 | ||||
| D | Sh | IN | D400 | D500 | D600 |
| 600 | 200 | 100 | 2 380 | 3 090 | |
| 300 | 2 485 | ||||
| 375 | |||||
| 400 | 2 990 | ||||
| 250 | 100 | 3 110 | |||
| 150 | 3 180 | ||||
| 200 | 2 910 | ||||
| 300 | |||||
| 400 | |||||
| 300 | 100 | 3 090 | |||
| 200 | 2 990 | ||||
| 625 | 250 | 150 | 3 180 | ||
| 200 | 2 990 | ||||
| 300 | |||||
| 300 | 200 |
In relation to Moscow and the region. Data on the most popular blocks in the private sector.
Is it possible to get rid of the cons?
Properly selected blocks guarantee strong walls
As you can see, gas silicate blocks have pros and cons, like any other building material. Let's figure it out - is it possible to get rid of shortcomings in order to get the home of your dreams?
Unfortunately, nothing can be done with low strength. You need to choose the right material based on the future load on the walls. As mentioned above, the density of blocks can vary from 300 to 600 kg per cubic meter. Of course, the more weight, the higher the cost, but the strength also increases. When constructing the walls of a one-story house, it is advisable to use material with a density of 400 or 500 kg/m3(depending on the thickness of the walls and future loads on them). They are able to withstand significant loads without harm to themselves. If you decide to build a two-story house, it is better to purchase blocks with a density of 600 kg/m3 - they are stronger. Alas, from construction tall buildings you will have to refuse - the material simply will not withstand the load.
Another disadvantage is moisture absorption. The only way to fix the problem is reliable protection. Plastering and painting in this case will not achieve the desired result. As practice shows, plaster does not last too long on the surface of gas silicate blocks. The house inevitably shrinks, which is why the plaster becomes covered with a web of cracks, and sometimes it simply crumbles, leaving the blocks defenseless against moisture. And a layer of paint disrupts gas exchange, causing the material to lose one of its main advantages.
Finishing walls made of gas silicate blocks with siding
Therefore, the best solution in this situation is siding. The walls are sheathed with special membrane material, allowing for effective removal of moisture from the premises, and at the same time, protecting the walls from rain, snow and other precipitation
Siding not only makes the house attractive, eliminating another important drawback, but also protects it from mechanical loads.
A fairly popular method of finishing walls made of gas silicate blocks is mineral wool insulation. Fasteners mineral wool to the wall, is done with special dowels, as a result of which it is not detached from the wall. After the mineral wool is reinforced with a mesh, it is pressed into the adhesive layer. After complete drying, putty is applied to the glue in two layers, rubbed, primed and painted.
We must not forget about waterproofing the walls from below. Before laying the first row of blocks, 2 layers of construction polyethylene or roofing felt are placed on the foundation. If you need to protect the walls from moisture after they have been laid, you can use mastic - it covers several lower rows, which allows you to protect the blocks from moisture, and at the same time, almost does not disturb gas exchange.
With this approach, you can completely rid the material of all the most important shortcomings.
Now you know all the pros and cons inherent in a house made of gas silicate blocks, and also have an idea of how to eliminate the latter. So, you have a great opportunity to acquire a cozy, reliable, beautiful and warm home.
Structure and appearance of concrete
Aerated concrete and aerated silicate are classified as cellular concrete, so both products are similar in appearance and structure. Both materials consist of a large number of pores filled with air, due to which the walls have high thermal insulation properties. The number of cells determines the grade of the blocks in both cases - the fewer, the stronger the block. However, higher grades lose strength in thermal insulation.
Gas silicate white, which is given to it by the lime used as a filler. Aerated concrete has a dark gray tint due to the use of cement as a binding component.
What you need to know about aerated concrete when choosing it for construction
When purchasing gas silicate blocks, it would be useful to remember some of their features, namely:
- frost resistance– the greater and more frequent temperature changes occur, the more the material wears out and becomes brittle. The importance of the parameter is directly related to the climatic zone in which the building is located - with high humidity, its service life is greatly reduced;
- moisture resistance and vapor permeability– silicate material cannot boast of hydrophobicity, which is largely due to the addition of lime during production. The more cement is used according to the preparation recipe, the less moisture will be absorbed by the blocks;
- shrinkage– the ability of blocks to noticeably reduce their size, which is observed immediately after the production of the material or its installation, so there is no need to rush during construction.
A quickly completed wall may turn out to be defective due to the appearance of cracks associated with the distortion of the material that has undergone shrinkage.
Useful properties of gas silicate blocks
- Non-flammability. The downside is that the fire resistance limit is not very high - only up to 400? C. This means that walls cannot be made from this material production workshops related to the use high temperatures s. When installing a stove in a house, it is necessary to provide a thermally insulating wall made of brick or clay.
- Environmental friendliness. Gas silicate blocks are made from components that can pose a danger only directly during production - lime, cement and aluminum powder. After the solution hardens, all substances are in a bound state, therefore they are safe for builders and future residents.
The only point at which it is advisable to control the purchased blocks is their radiation background. It can be easily checked using a household dosimeter.
The low toxicity of gas silicate blocks deserves a rating of 4 points. A slight underestimation is due to the large amount of dust that is formed during the gating of walls and other types of finishing.
Advantages and disadvantages of gas silicate blocks
The main advantages of gas silicate are the following.
- Ease. Gas silicate blocks weigh almost 5 times less than concrete products the same sizes. This facilitates construction work and reduces the cost of transporting building materials.
- Effective heat and sound insulation. Due to the presence of internal micropores, high heat and noise insulation characteristics of gas silicate are achieved. This allows you to create a comfortable indoor microclimate.
- Environmental friendliness. The building materials do not contain dangerous toxins and carcinogens that can cause harm to the environment and human health.
- Fire resistance. Gas silicate is made from non-flammable raw materials, therefore it does not collapse under intense heating and does not contribute to the spread of flame in a fire.
Production technology
Lime, sand and water, taken in certain proportions, are placed in a concrete mixer. After this, using a special dispenser, aluminum powder is poured into it. The mixture is laid out in molds and left for four hours at a temperature of forty degrees Celsius.
Calcium hydroxide begins to react with aluminum, actively releasing hydrogen. The raw material mass begins to foam and increase in volume, like yeast dough.
As soon as the evolution of hydrogen stops, the mixture becomes plastic. The finished array is divided into even blocks, which are sent to autoclave units. Under a pressure of 14 bar and a temperature of 180 degrees, the material is further dried.
The pores can contain up to eighty percent air, and this figure depends on the brand of gas silicate blocks. But quartz sand gives the blocks the necessary strength.
Gas silicate and aerated concrete features of porous material
Let's look at the difference between gas-filled concrete and gas silicate blocks:
- aerated concrete is composite material, produced using standard technology with natural hardening. Characterized by the porous structure of the massif. It is characterized by a uniform arrangement of spherical air cells, the diameter of which is no more than 3 mm. The properties of the product depend on the distribution of air pores in the concrete mass. The basis of the material is Portland cement, the concentration of which is more than 50%. The binder determines the color of the finished product. To achieve the required characteristics, an autoclave manufacturing method can be used;
- gas silicate products also contain air cells. The main components used in the production of silicate are quartz sand and lime. Their ratio is 3:1. The standard recipe involves the introduction of aluminum powder for gas formation and the addition of water to the required consistency. Manufacturing takes place using autoclave technology. They are heat treated under high pressure conditions. Prepared gas silicate mixture forms are filled out. After heat treatment, the array is cut into products of the required dimensions.
Despite the fact that both materials belong to porous concrete, each material has certain characteristics.
The disadvantages of aerated concrete and gas silicate materials appear, as a rule, already at the operation stage
What are gas silicate blocks
Gas silicate is a building material for the construction of capital and partition walls, fences and other enclosing structures. Belongs to the group of cellular concrete, produced by autoclave (industrial) and non-autoclave (handicraft) methods from:
- Mixtures of binders: Portland cement and quicklime;
- Silica filler;
- Aluminum powder;
- Water.
The gas silicate contains lime, which ensures an active reaction with the foaming agent. As a result, a large amount of hydrogen is released, the mass foams. Under production conditions, after steaming and hardening, a highly porous aerated concrete material. The finished product is cut into blocks of fixed dimensions: length - up to 60 cm, thickness - 20-25 cm, height - 10-50 cm. In the video below you can see manufacturing process fully:
Depending on the density, gas silicate is divided into:
- Structural with a compressive strength of D700 and above. This material is used for the construction of capital walls;
- Structural and thermal insulation with grade D500-D700 - intended for partitions and walls with a height of no more than standard 2 floors;
- Thermal insulation – D400. It is used not to build new walls, but to improve the thermal capacity characteristics of existing ones.
Gas silicate blocks are used in private housing construction, as well as for the construction of combined, insulated structures in high- and low-rise buildings, industrial buildings, etc.
Advantages of gas silicate blocks
Gas silicate blocks
This material has gained considerable popularity not only in the construction of residential buildings, but also outbuildings - from chicken coops to garages. This was made possible due to the following advantages:
- low cost when comparing gas silicate blocks with brick;
- low weight is guaranteed by low density - from 300 kg/m3 to 600 kg/m3. That is, it is comparable to most types of wood used in construction;
- excellent thermal insulation characteristics. The thermal conductivity of a wall made of gas silicate blocks is 8 times less than that of brick. This advantage has brought popularity to the blocks in countries with harsh climates;
- a high rate of thermal accumulation significantly reduces home heating costs. Even Vacation home empty during the winter months, it can be heated in a matter of hours, burning a minimum of fuel;
- non-flammability - even direct contact with open fire does not harm the material;
- good sound insulation - in this indicator the material is 10 times superior to brick;
- excellent vapor permeability creates a healthy atmosphere in the house - being in such houses is pleasant and comfortable;
- environmental friendliness.
As you can see, gas silicate blocks have many significant advantages. But it is not enough to know only about them - being aware of the shortcomings of the material is even more important.
Thermal conductivity of walls
When building houses for permanent residence, strength alone is no longer enough. Here also it is necessary to take into account the thermal conductivity of the materials used. In accordance with the calculations, either the required thickness of the blocks for your climate zone is determined, or the thickness remains as for summer buildings, but additional insulation is used. 
And in this case, you need to calculate in terms of money what will be cheaper - increasing the thickness of the wall due to aerated concrete or insulation.
Important! When calculating the cost of insulation, it is worth adding the price of fasteners and payment for the work of builders.
In accordance with GOST, which regulates the main technical parameters, as well as the compositional characteristics and dimensions of absolutely all cellular blocks, the thermal conductivity of such building material is 4 times lower than similar indicators of solid brick, which makes it possible to erect structures with narrower walls.
The thermal conductivity coefficient of a material is its ability to conduct heat. Calculated indicator of the amount of heat passing through 1 m3 of a material sample in 1 hour at a temperature difference on opposite surfaces of 1 ° C.
I will give a detailed comparison with solid brick. The thermal conductivity of aerated concrete is approximately 0.10-0.15 W/(m*°C). For brick this figure is higher - 0.35-0.5 W/(m*°C).
Thus, to ensure normal thermal efficiency of a residential building for the Moscow region (where the air temperature in winter rarely drops below -30 degrees) the brick wall must be at least 640 mm thick. And when used in construction aerated concrete blocks D400 with a thermal conductivity of 0.10 W/(m*°C) walls can have a thickness of 375 mm and conduct the same amount of thermal energy. For D500 blocks with a thermal conductivity of 0.12 W/(m*°C), this figure will be in the range from 400 to 500 mm. Detailed calculation will be below.
Thermal conductivity indicators depending on wall thickness:
| Aerated concrete | Wall width (cm) and thermal conductivity indicators | |||||||||||
| 12 | 18 | 20 | 24 | 30 | 36 | 40 | 48 | 60 | 72 | 84 | 96 | |
| D-600 | 1.16 | 0.77 | 0.70 | 0.58 | 0.46 | 0.38 | 0.35 | 0.29 | 0.23 | 0.19 | 0.16 | 0.14 |
| D-500 | 1.0 | 0.66 | 0.60 | 0.50 | 0.40 | 0.33 | 0.30 | 0.25 | 0.20 | 0.16 | 0.14 | 0.12 |
| D-400 | 0.8 | 0.55 | 0.50 | 0.41 | 0.33 | 0.27 | 0.25 | 0.20 | 0.16 | 0.13 | 0.12 | 0.10 |
Between the thermal conductivity coefficient and the thermal insulation of walls there is inverse proportionality, which must be taken into account when performing independent calculations.
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Gas silicate blocks pros and cons
When building a cottage or low-rise building, the main expense and financial expenses– building material for load-bearing walls and internal partitions. When constructing such projects, builders often recommend gas silicate blocks. They save time and money spent on construction
And this is their main difference from the construction of gas silicate from conventional brick. Let's give short review: what are the main pros and cons of gas silicate blocks.
- loading/unloading of gas silicate blocks can be done by one person, despite its size, the block is light in weight;
- thanks to a large number voids, the material has excellent sound-absorbing properties;
- it is easy to give the block the desired shape and size; an ordinary hacksaw is enough;
- houses made from gas silicate blocks are energy efficient and heat saving; the material has fairly low thermal conductivity;
- the speed of construction of walls and partitions increases significantly, the dimensions of a standard block are much larger in comparison with 1NF bricks;
- By fire safety, gas silicate belongs to group G1 (group of low-flammable materials);
- the cost of the material is much lower than analogues.
- gas silicate does not burn; the material begins to deteriorate on a physical level at temperatures above 700 degrees Celsius. If the fire temperature exceeds this indicator, the building is practically beyond repair. Further residence in this house or cottage is impossible;
- When moisture gets on the gas silicate, it is almost completely absorbed. When the temperature drops below zero, the water in the voids turns into ice and destroys the block. The material has a high degree of water absorption.
Walls and partitions made from blocks are “breathable”, have high vapor permeability, and houses made from them are environmentally friendly and comfortable. But such a structure should not exceed a height of two floors, otherwise the lower blocks will collapse under the pressure of the structure.
Minuses
Private developers often express negative opinions about gas silicate and aerated concrete and report on their experience in building and operating houses from these materials. Based on the reviews, we can draw conclusions about the inherent shortcomings of these blocks.
Hygroscopicity
Gas silicate has one significant disadvantage that can minimize and negate all the advantages of this material: a high degree of hygroscopicity. It identifies many problems that arise during the construction and operation of houses.
The moisture permeability of porous stones is due to the presence of air in them. It is able to penetrate into the smallest cracks and fill them. The moisture contained in it is absorbed by a mixture of sand and lime (components of the gas silicate composition). Aerated concrete is also exposed to the same danger, since the presence of cement in it is not a barrier to the penetration of water into the structure of the block.
We draw conclusions: a wet block is a cold block. Consequently, the thermal characteristics of the material declared by the manufacturer correspond to the conditions of its operation: at low or normal humidity air.
In reality, this cannot be achieved, since a natural phenomenon - precipitation in the form of rain and snow - will always increase the level of humidity in the atmosphere surrounding the house. In addition, this indicator is inevitably affected by the proximity of bodies of water: rivers, ponds, pools.
To confirm the information presented, one of the recommendations regarding cellular concrete can be cited.
According to clause 1.7 of the “Reference Guide to SN and P for engineering and technical workers of research and design organizations,” cellular concrete, including gas silicate blocks, is classified as non-moisture-resistant and non-bioresistant materials, not recommended for the construction of walls of rooms with damp and wet conditions.
Beams can be used to protect external walls
Fragility
For all its advantages, gas silicate has low bending strength. This causes the fragility of the blocks and the appearance of cracks in walls and partitions. The lack of elasticity makes gas silicate structures responsive to the slightest deformation.
Practice shows that houses higher than three floors are not built from this material. For construction high-rise buildings blocks required high density: from D700, with lower thermal insulation characteristics. The cost of construction increases significantly, as the cost of purchasing more expensive blocks, heat and waterproofing materials increases.
But even for a three-story building, a high-quality foundation made of heavy concrete is required.
Moreover, it is important that the foundation of the house has a high load-bearing capacity and has a perfectly flat, horizontal surface. In this case, the risk of shrinkage deformation of the walls and the formation of cracks in them is minimal
The experience of builders suggests that without a reliable foundation, it makes no sense to get involved with cellular concrete. When choosing MZL or a shallow slab as the base, experts recommend building the basement floor from brick. And only after that start laying gas blocks.
A poorly laid foundation leads to cracking of gas silicate
Low mechanical strength
To secure massive structures, heat and waterproofing materials to gas silicate walls, you will need special fasteners. Ordinary ones, in the form of disc-shaped dowels, will not work. Blocks made of cellular concrete have a fairly loose structure, so they require special screw-in dowels or chemical anchors. The price for these fasteners is 5–6 times higher than for disc fasteners.
On average, the cost of insulation, waterproofing or finishing 1 m2 only due to the use of specialized fasteners increases by 250–300 rubles. The total area of the facade of a private house is at least 300 m2, so this feature of gas silicate blocks leads to a significant increase in the cost of construction estimates.
The structural type of gas silicate has low thermal insulation
Main characteristics of gas silicate blocks
As already mentioned, gas silicate blocks (the pros and cons of which are explained primarily by their characteristics) have a porous structure. Due to this, their low thermal conductivity is ensured. , as well as high vapor permeability.
The latter factor contributes to the creation of a microclimate in the room that is favorable for humans. Gas silicate blocks are not susceptible to rodents, insects, or rotting. They are fire-resistant (withstand open flames for several hours), and at the same time are characterized by high frost resistance.
Although the density of such blocks is low, they are highly durable, so they can be used in the construction of load-bearing walls of buildings.
The existing range of building materials allows you to build almost any building, but the catch is that the requirements for them are constantly increasing. The building material must be durable and strong, have low specific gravity and, of course, to be.
Not all natural materials can boast similar characteristics, however, gas silicate blocks combine the entire set of the above useful properties.
The weaknesses of this material include high water absorption, which reduces its frost resistance and thermal insulation properties. In this regard, if the air humidity is more than 75%, there is a need for protective plastering.
The next disadvantage of gas silicate blocks is a decrease in their thermal insulation properties with increasing strength and density of the material.
Independent rating of manufacturers
Before starting construction, it is important to choose a materials manufacturer that supplies the market with quality products. In the Russian region, the following companies have earned consumer trust: .
JSC "Ksella-Aeroblock Center"
This is a German company, part production capacity which is located in Russia. The company's products are known all over the world for their inherent German quality. It is curious that the XELLA company operates in several directions, three of which are aimed at the extraction and subsequent processing of raw materials.
JSC "EuroAeroBeton" The company has been specializing in the production of gas silicate blocks since 2008. The company has its own production lines, which use an automated process and use equipment from the world's leading brands. The plant is located in the Leningrad region, the city of Slantsy.
LLC "LSR. Construction-Ural". The company's head office is located in Yekaterinburg, the plant occupies a leading position in the Urals. The company has a half-century history, uses an automated production process, and controls quality at all stages.
CJSC Lipetsk Silicate Plant. The history of the enterprise began in 1938; it is one of the main suppliers of the central region of Russia. In 2012, the company received an international certificate according to the ISO 9001.2008 class, which indicates high quality products.
OJSC "Kostroma Silicate Plant". This is one of the oldest enterprises in the country, founded in 1930. Over the years of its existence, a special charter has been developed that allows us to bring the quality of products to a fundamental level. new level. The company values its reputation and boasts the absence of negative reviews from consumers.
- JSC "Ksella-Aeroblock Center". This is a German company, part of whose production facilities are located in Russia. The company's products are known all over the world for their inherent German quality. It is curious that the XELLA company operates in several directions, three of which are aimed at the extraction and subsequent processing of raw materials.
- JSC "EuroAeroBeton". The company specializes in the production of gas silicate blocks with 2008. The company has its own production lines, which use an automated process and use equipment from the world's leading brands. The plant is located in the Leningrad region, the city of Slantsy.
- LLC "LSR. Construction-Ural". The company's head office is located in Yekaterinburg, the plant occupies a leading position in the Urals. The company has a half-century history, uses an automated production process, and controls quality at all stages.
- CJSC Lipetsk Silicate Plant. The history of the enterprise began in 1938, is one of the main suppliers of the central region of Russia. IN 2012, the company received an international class certificate ISO 9001.2008, which indicates high quality products.
- OJSC "Kostroma Silicate Plant". This is one of the oldest enterprises in the country, founded in 1930 year. Over the years of existence, a special charter has been developed that allows us to bring the quality of our products to a fundamentally new level. The company values its reputation and boasts the absence of negative reviews from consumers.
Please note that this is not a complete list of trustworthy manufacturers of gas silicate blocks in the Russian region. However, the products of these brands are the optimal ratio of cost and quality.
Advantages and disadvantages
The advantages of gas silicate material include the following positive qualities:
- Light weight - no need to use loading and unloading equipment. Having a masonry tool, you can carry out construction work yourself;
- numerous void spaces guarantee excellent insulation from extraneous noise;
- blocks are easy to process manual material– a hacksaw, grater, etc.;
- low level of thermal conductivity - the house will be warm, a comfortable microclimate will always be maintained indoors;
- construction work is completed quickly because the blocks are large in size. If there is a special grip, the block is convenient to move and stack;
- the material belongs to the group of low-flammable materials.
Objects made from such material are comfortable and environmental safety. The excellent vapor permeability of the blocks allows the walls to “breathe”. But a house made of such material is built on two floors, and if the gables are high, then on one. Otherwise, the lower rows of masonry may collapse from the heavy weight.
Except positive qualities, there are also negative aspects. The block is considered a non-combustible material, but can be destroyed when exposed to high temperatures. Heavy fire will make an object made of gas silicate material unsuitable for further use.
Another problematic issue is moisture absorption. Water that gets onto an aerated concrete surface almost immediately ends up inside the stone. During severe frosts, “wet” blocks may crack. To protect the material from excess moisture, water repellents are used.
What disadvantages do these blocks have?
Crack on a gas silicate block
The main disadvantage of gas silicate sides is strength. Unfortunately, these blocks poorly withstand both bending and tension loads, and compression. Therefore build multi-story houses You can’t get out of it - the walls will collapse under their own weight. They are often damaged during transportation and installation. To avoid having to interrupt work due to a lack of material, it is advisable to purchase it in reserve; the number of additional blocks depends on the amount of work. Yes, this will increase financial costs. But there are guaranteed to be enough blocks to complete construction.
Another important drawback is moisture absorption. This leads to a whole range of problems. Firstly, mold may appear on a block saturated with moisture, both on the outside and on the inside. Secondly, significant moisture absorption is the reason for low frost resistance. If the blocks are saturated with water, then when they freeze, it will destroy its pores, reducing the already not very high strength of the material.
The disadvantages can also be attributed to external attractiveness of gas silicate blocks. Light gray walls with streaks of dark gray mortar are unlikely to please even the most undemanding owner. Therefore, aesthetic appeal cannot be included in the list of advantages of the material. Such disadvantages significantly narrow the scope of application of gas silicate blocks.
Properties
The characteristics that distinguish gas silicate blocks allow us to consider them as a building material that is well suited for the construction of buildings. Experts say that aerated concrete combines the best qualities of stone and wood - its walls are durable and protect well from the cold.
The porous structure of the blocks guarantees high fire safety indicators
The cellular structure explains the low thermal conductivity coefficient - it is much lower than that of brick. Therefore, buildings made of gas silicate material are not so demanding in terms of insulation - in some climatic zones it is not required at all.
Below we present the main properties of gas silicate, thanks to which it has become so popular in the construction industry:
- small weight with impressive dimensions– this property allows you to significantly reduce installation costs. In addition, a crane is not required for loading, transportation and erection of walls - an ordinary winch is sufficient. For this reason, the speed of construction is also much higher than when working with brick;
- good machinability– a gas silicate block can be sawed, drilled, milled without any problems, using ordinary tools;
- high environmental friendliness– experts say that this indicator for aerated concrete is comparable to wood. The material does not emit any harmful substances and does not pollute the environment, and, unlike wood, it does not rot and is not subject to aging;
- manufacturability– gas silicate blocks are made in such a way that they are easy to work with. In addition to their small weight, they are distinguished by their convenient shape and technological recesses, grips, grooves, etc. Thanks to this, the speed of working with them increases 4 times compared to the construction of brick buildings;
- low thermal conductivity of gas silicate blocks– it is due to the fact that aerated concrete consists of 80 percent air. In buildings built from this material, heating costs are reduced, and they can also be insulated one-third less;
A house made of gas silicate will maintain a stable microclimate at any time of the year.
- frost resistance– there are special voids in the structure where moisture is displaced when it freezes. If all are sustained technical requirements before production, the frost resistance of aerated concrete exceeds two hundred cycles;
- soundproofing– a very important parameter, since today the noise level on the streets is quite high, and at home you want to relax in silence. Due to its porous structure, gas silicate retains sound well, comparing favorably with brick in this regard;
- fire safety – minerals, which are used to make gas silicate, do not support combustion. Gas silicate blocks can withstand fire for 3-7 hours, so they are used for the construction of chimneys, elevator shafts, fire-resistant walls, etc.;
- high strength– gas silicate can withstand very high compressive loads, therefore it is suitable for the construction of buildings with load-bearing walls up to three floors high or frame-monolithic buildings without any restrictions;
- non-hygroscopic– aerated concrete does not absorb water, which, once on it, dries quickly, leaving no traces behind. This is explained by the fact that the porous structure does not retain moisture.
The main disadvantage of gas silicate is its insufficient bending strength, but the specifics of its use are such that it practically eliminates the possibility of bending loads, so this disadvantage does not play a big role.
The less air in the body of an artificial stone, the higher its strength and density
Projects
Approximate standard projects using gas silicate blocks. The photo below shows typical projects.
House
IN modern world gas silicate is one of the most popular materials in construction low-rise buildings and cottages. Thanks to low price and its unique properties, the material has received the widest application, enjoys well-deserved popularity and steady demand.
In addition to saving money, a house made of gas silicate blocks allows you to get a durable and safe structure. Very important criterion – the speed of construction of the entire structure as a whole.
House designs made from gas silicate blocks surprise with their diversity. The best of them amaze with their non-standard approaches to design. Due to its low weight, the construction of the building allows for a shallow, strip foundation.
gas silicate blocks
Here it is worth focusing on the mandatory use of a durable waterproofing layer. It is designed to protect the lower layer of gas silicate from moisture penetration
A reinforced concrete slab will serve as an excellent base for the floor of the first floor. If the layout includes a gas silicate floor, it is necessary to lay a strong and rigid foundation.
An attic made of gas silicate allows you to give the room a whimsical, unusual shapes and at the same time transform the ordinary, attic space into a cozy and warm room, or even more than one.
Bath
When building a gas silicate bath, blocks of the brand are used at least 400. Due to the nature of its operation, a bathhouse made of gas silicate blocks must have a mandatory hydro- and vapor barrier internal surfaces. A concrete slab or shallow foundation is suitable for the base.
gas silicate blocks
During construction, it is mandatory to protect all walls and partitions from moisture. Regular plastic film is sufficient. Suitable for exterior decoration facing brick, siding, etc.. For interior finishing (after waterproofing) it is most often used clapboard or wooden board.
Garage
For garage construction, gas silicate blocks are the most optimal choice. Decisive factors in the choice of materials – low cost and speed of construction of walls and partitions, shallow depth of the required foundation, heat and sound insulation. It is enough to take into account the nuances during construction, such as waterproofing on the bottom layer of masonry and external walls. Interior finishing to choose from. Since this non-residential premises the options are endless.
gas silicate blocks
Gas silicate block D500 building material characteristics
The structural and thermal insulation block of the D500 brand is used for various purposes:
- construction of boxes of low-rise buildings;
- arrangement of interior partitions;
- strengthening door and window openings.
Gas silicate blocks provide good thermal insulation of the room
Having decided to purchase block silicate marked D500, you should familiarize yourself in detail with the performance properties of the popular building material. Let's look at the main characteristics.
Strength properties
The compressive strength class of the material varies depending on the method of manufacturing the blocks:
- gas silicate grade D500, produced by the autoclave method, is characterized by a strength index of B2.5-B3;
- The compressive strength class for similar blocks produced using non-autoclave technology is B1.5.
The strength of D500 blocks reaches 4 MPa, which is not high enough. To prevent cracking of the gas silicate material, the masonry is reinforced with mesh or reinforcement. The relatively low safety margin allows the use of block building materials in low-rise construction. When constructing multi-storey buildings, gas silicate blocks are used together with bricks for thermal insulation of the walls being built.
Specific gravity
The density of gas silicate blocks is an important performance indicator that characterizes the porosity of the block mass. Density is indicated by markings in the form of the Latin letter D and a digital index. The number in the marking characterizes the mass of one cubic meter of gas silicate. Thus, one cubic meter of gas silicate marked D500 weighs 500 kg. Knowing the marking of products by density, the size of the blocks and their number, it is easy to calculate the load on the foundation.
Gas silicate blocks - environmentally friendly material
Thermal conductivity characteristics
The thermal conductivity of gas silicate blocks is the ability to transfer thermal energy. The value of the indicator characterizes the thermal conductivity coefficient of gas silicate blocks.
The value of the coefficient varies depending on the moisture concentration in the material:
- the thermal conductivity coefficient of dry gas silicate material grade D500 is 0.12 W/m⁰С;
- with an increase in humidity to 5%, the thermal conductivity of D500 blocks increases to 0.47 W/m⁰С.
In buildings built from gas silicate blocks, due to the reduced thermal conductivity of the material, a favorable microclimate is maintained year-round.
Frost resistance
The ability of gas silicate blocks to withstand temperature changes associated with deep freezing and thawing is characterized by markings. The frost resistance index for D500 products is F50. Compared to other types of composite concrete, this is a pretty good indicator. Frost resistance is affected by the moisture concentration in the blocks. As the moisture content of the material decreases, the frost resistance of the blocks increases.
Lifetime
Gas silicate has a long period of use. The structure of the gas silicate massif has maintained its integrity for more than half a century. Manufacturers of blocks guarantee a service life of products for 60-80 years, provided that the blocks are protected from moisture absorption. Plastering the material allows you to extend its service life.
Fire safety
Gas silicate blocks are a fireproof building material with fire resistance up to 400 ⁰C. Tests confirm that covered with plaster gas silicate wall can withstand exposure to open fire for three to four hours. The blocks are suitable for the construction of fire-resistant walls, partitions and chimneys.
Advantages and disadvantages
The construction of houses from gas silicate blocks is quite justified by the low cost of the material and its many advantages:
- Blocks intended for building houses are highly durable. For material medium density 500 kg/m³ mechanical compression index 40 kg/cm3.
- The low weight of gas silicate products allows you to avoid additional costs when delivering and installing blocks. The cellular material is five times lighter than conventional concrete.
- Due to good heat transfer, heat energy consumption is reduced. This property allows you to significantly save on heating the building.
- High sound insulation rate. Due to the presence of pores, the cellular material protects against noise penetration into the building ten times better than brick.
- Good environmental properties. The blocks do not contain toxic substances and are completely safe to use. In many environmental indicators, gas silicate is equal to wood.
- The high vapor permeability of the products allows you to create good microclimate conditions in the room.
- Non-flammable material prevents the spread of fire in the event of a fire.
- The exact proportions of the block sizes make it possible to make even wall laying.
- Affordable price of material. With good technical indicators, the price of gas silicate blocks is relatively low.
A house made of gas silicate blocks allows you to significantly save on heating
Along with a considerable number of advantages, porous material has some disadvantages:
- The mechanical strength of blocks is slightly lower than that of reinforced concrete and brick. Therefore, when driving nails into the wall or screwing in dowels, the surface easily crumbles. The blocks hold heavy parts quite poorly.
- Moisture absorption ability. Gas silicate absorbs water well and quickly, which, penetrating into the pores, reduces the strength of the material and leads to its destruction. When constructing buildings from various types of porous concrete, surfaces are protected from moisture. It is recommended to apply plaster on walls in two layers.
- The frost resistance of blocks depends on the density of the products. Gas silicate grades below D 400 are not able to withstand a cycle of 50 years.
- The material is prone to shrinkage. Therefore, especially for blocks of grades below D700, the first cracks may appear a couple of years after the construction of the building.
When decorating walls made of gas silicate, gypsum plaster is mainly used. It perfectly hides all the seams between the blocks. Cement-sand mixtures are not retained on a porous surface, and when the air temperature drops, small cracks form.
The popularity of gas silicate is increasing every year. Cellular blocks have almost all the qualities necessary for the effective construction of low-rise buildings. Some characteristics far exceed those of other materials. Using lightweight gas silicate blocks, you can build a reliable building at low cost in a relatively short time.
Classification of gas blocks
Differences in shape:
Smooth gas blocks. Classic look piece building material made of artificial stone. Such blocks have the shape of a parallelepiped with sides of different sizes. This gas block is universal, it can be used for the construction of structures for various purposes.
Gas block with tongue groove. The tongue-and-groove mounting system significantly strengthens the structure and saves assembly adhesive. If after construction the walls are plastered, then there is no need to apply glue to the ends of the blocks. Each block has a groove into which the ridge of the next block is inserted. This ensures a rigid bond between the masonry.
U-shaped gas blocks. This design is necessary for construction and greatly simplifies construction. individual designs building. U-shaped blocks are used to create lintels over openings in the wall or monolithic reinforced belt rigidity. A number of such blocks form a gutter. Reinforcement is placed in it according to calculations and concrete is poured. After this, the concrete is compacted and left to dry for some time.
NN-shaped gas blocks. Such blocks are used as formwork for complex building structures.
Differences in purpose:
Structural. Used to construct partitions and other structures that do not have load-bearing functions. Can be used for the construction of temporary or auxiliary buildings.
Structural and thermal insulation. This is the most popular material that is most often used to build a private house. Such blocks have thermal insulation properties and are strong enough for the construction of load-bearing structures.
Thermal insulation. It has a low level of thermal conductivity, which ensures a comfortable temperature in a house made of this material. But the strength of these blocks is very low, so they are not used for the construction of load-bearing structures. It is best to use thermal insulation blocks for the construction of external curtain walls. Such blocks perform the function of thermal insulation and fencing.
Today there is a lot of competition among manufacturers. Many companies have already earned authority in the building materials market. The most famous are the Dutch company "HESS AAC Systems", "N+N", one of the pioneers in Russia "SIBIT", and "AEROC".
There are many other manufacturers that provide a full range of aerated concrete blocks. To purchase the required volume of material for building a house, you need to determine how many gas blocks are in 1 cube, since the sizes of the blocks vary. The following table will help you correctly determine how much material you need.
Table of parameters of individual blocks and packaging.
| Product | Options | Block volume, m3 | Package volume, m3 | Number of blocks in the package | ||
|---|---|---|---|---|---|---|
| Length | Height | Width | ||||
| Gas block of the 1st grade. Brands D400, D500 | 600 | 200 | 75 | 0,009 | 1,8 | 200 |
| 100 | 0,012 | 1,8 | 150 | |||
| 150 | 0,018 | 1,8 | 100 | |||
| 250 | 0,03 | 1,8 | 60 | |||
| 300 | 0,036 | 1,8 | 50 | |||
| 350 | 0,042 | 1,68 | 40 | |||
| 375 | 0,045 | 1,8 | 40 | |||
| 400 | 0,048 | 1,44 | 30 |
Depending on the production technology and the proportions of the constituent components of the material, gas blocks have different physical and technical parameters. According to these technical indicators, each product must be labeled.
Table of brands and their technical properties.
Continuing the topic of building materials based on concrete and various additives, we will analyze such a popular material as gas silicate blocks. Many advantages, as well as versatility of use, have brought this material highly popular in many regions of the world, including in our country.
The blocks are based on high-quality cement, gypsum, lime and water. All these materials are mixed together, after which aluminum powder is added to the solution. The latter reacts with lime, causing the release of gas and the composition is filled with small pores. Modern technologies allow you to adjust the size of the pores.
After mixing the material, pouring it into molds and cutting the latter, the blocks are sent to autoclaves, where they undergo the final strengthening and impart those performance characteristics for which gas silicate is valued. However, there is also a non-autoclave production method, but in this case gas silicate blocks are less durable and less environmentally friendly.
Advantages of gas silicate blocks
- The gas silicate block has high compressive strength. This is a reliable building material that will allow you to create strong load-bearing or internal walls. Naturally, we are talking about load-bearing structures in low-rise construction;
- Ease. Aerated concrete is five times lighter than conventional concrete and has high strength. Light weight not only facilitates construction, but also makes it possible to save time and money on the construction of a massive foundation;
- The material is 8 times superior to ordinary concrete in terms of thermal insulation properties. In winter, you will spend less resources on heating, even if you save on wall insulation during construction;
- The porous structure makes the gas silicate block an order of magnitude more effective sound insulator than brick;
- Such blocks are mainly manufactured by highly qualified professionals. So the quality of the product is usually very high. Deviations are minimal, so that, with proper laying, the walls will be as smooth as possible;
- For rodents, gas silicate blocks are of no interest;
- Large sizes allow you to build walls much faster than with brick. At the same time, you can work independently. By following a number of simple rules, you can build a structure from these blocks without much knowledge in construction;
- The material is completely environmentally friendly and is not subject to fire;
- High vapor permeability allows for complete gas exchange, creating a pleasant microclimate in the premises.
Disadvantages of the material
- Hygroscopicity, as is the case with other options for cellular concrete, is very high for gas silicate blocks. Having absorbed a lot of water, such a block becomes susceptible to destruction, loses its performance characteristics, and also provides the fungus with an excellent environment for reproduction. As a result, additional waterproofing measures are required;
- Low strength. When attaching heavy structures to walls, it is necessary to use special dowels;
- Mediocre frost resistance, which also increases the cost of protective measures;
- Shrinkage of these materials can be quite significant. For this reason, every three to four rows it is better to use reinforcing mesh or reinforcement. Otherwise, the walls may crack over time;
- As is the case with all porous concrete, thermal insulation properties decrease as strength characteristics increase.
Glue or cement?
Laying of gas silicate blocks is done either on a standard cement-sand mortar, or with specialized glue. What to choose? First of all, it is worth noting that both fastening substances have a higher thermal conductivity than the gas silicate blocks themselves.
On the cement side the cost is several times lower. The disadvantage is the large thickness of the layer, which increases the width of the cold bridges. The glue allows the blocks to be almost end-to-end, which is very good. However, for laying the first layer of blocks directly on the concrete base cement mortar you will still need it, since it will allow you to perform the necessary alignment in this case.
Technology for laying gas silicate blocks
We will describe the construction of a foundation, which can be strip, in more detail in another article, since this topic is very large. As for the actual laying of blocks, the first row is placed on the concrete mixture from the highest corner of the foundation. If necessary, we make additional adjustments using a solution. Use levels.
- Important! High ability The ability of the gas silicate block to absorb water must be taken into account when installing the first row of blocks on the solution. To prevent moisture from the latter from being absorbed into the block, the lower part of the block is wetted with water before installation on the concrete support.
All other rows can be laid with special glue. In this case, every three or four rows the walls should be reinforced in order to reduce shrinkage.
- Precast concrete slabs cannot be laid directly on this type of concrete blocks due to the latter’s insufficient strength. In this case, it is necessary to construct a reinforced concrete belt along the perimeter of the wall, made using monolithic construction technology. When constructing two-story and higher houses, reinforced concrete bearing structures required. In addition, reinforced concrete belts require thermal insulation;
- The strength of the block is one of the determining factors. If you are building a one-story structure, you will need a block with a density of at least half a ton per cubic meter. If we are talking about the construction two-story houses, then you need to choose options of 600 kilograms per cubic meter. We have already said that as strength increases, the insulating qualities are lost, so walls made from such a block must have a minimum of 40 centimeters in thickness. Otherwise you will need additional insulation. It is impossible to build a base from such blocks;
- Chips and other damage to the blocks are not allowed. Since the material is fragile, it must be transported, stored and handled carefully. Try to buy more blocks than necessary, as some may get damaged. It is necessary to cut blocks with a special tool and as carefully as possible.
