Gas silicate blocks purpose. Technical characteristics of gas silicate blocks

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One more popular material, which has captured a significant share in the building materials market is gas silicate. Ready-made molded blocks have much in common with artificial stone and have noticeable advantages. For this reason, gas silicate blocks have gained such wide popularity in the construction of houses.

Where are gas silicate blocks used?

The scope of application of gas silicate lies in the following areas:

thermal insulation of buildings,
construction of buildings and load-bearing walls,
insulation of heating networks.

In terms of their qualities, gas silicate blocks have much in common with foam concrete, but at the same time they surpass them in mechanical strength.

Depending on the density of the material. There are several areas of application:

The density of the blocks from 300 to 400 kg/m3 greatly limits their distribution, and such blocks are more often used as insulation for walls. Their low density does not allow them to be used as a basis for walls, since they will collapse under significant mechanical load. But low density plays a role as insulation, since the more tightly the molecules adhere to each other, the higher the thermal conductivity becomes and it is easier for the cold to penetrate into the room. Therefore, blocks with low thermal conductivity provide more effective thermal insulation,
blocks with a density of 400 kg/m3 have found their use in the construction of one-story buildings and work premises. Due to the increased strength of the blocks and their lower weight, the cost of arranging the foundation is significantly reduced,
blocks with a density of 500 kg/m3 are more often used in the construction of buildings several floors high. As a rule, the height of the building should not exceed three floors. Such blocks, directly depending on the climate, are either not insulated at all or require traditional insulation methods.
the best option for constructing high-rise buildings is to use blocks with a density of 700 kg/m3. This indicator allows the construction of high-rise residential and industrial buildings. Due to their lower cost, walls constructed from gas silicate blocks are replacing traditional brick and reinforced concrete walls.

The higher the density, the worse the thermal insulation performance, so such buildings will require additional insulation. More often, the external one is provided with the help of foam or polystyrene foam boards. This material has a low price and at the same time provides good thermal insulation premises at any time of the year.

Behind Lately The position of gas silicate as one of the most popular materials in construction has been significantly strengthened.

The relatively light weight of the finished blocks will significantly speed up the construction of the building. For example, gas silicate blocks, the sizes of which have standard values, according to some estimates, reduce the complexity of installation by up to 10 times compared to brick.

A standard block with a density of 500 kg/m3 and a weight of 20 kg can replace 30 bricks, the total mass of which will be 120 kg. Thus, installation of blocks on low-rise buildings will not require special equipment and will reduce labor costs and time spent on building construction. According to some estimates, time savings reach a 4-fold reduction in time costs.

Material characteristics

It makes sense to list the main technical characteristics of gas silicate blocks:

The specific heat capacity of blocks produced by autoclave is 1 kJ/kg*°C. For example, a similar indicator for reinforced concrete is at the level of 0.84,
the density of reinforced concrete is 5 times higher, but the thermal conductivity coefficient of gas silicate is only 0.14 W/m*°C, which is approximately the same as that of pine or spruce wood. Reinforced concrete has a significantly higher coefficient, 2.04,
the sound absorption characteristics of the material are at the coefficient level of 0.2, at a sound frequency of 1000 Hz,
The cycle of frost resistance for gas silicate blocks with a material density below 400 kg/m3 is not standardized; for blocks with a density up to 600 kg/m3 it is up to 35 cycles. Blocks with a density above 600 kg/m3 are able to withstand 50 freezing and thawing cycles, which is equal to 50 climatic years.

If we compare gas silicate blocks with brick, the indicators are not in favor of the latter. Thus, the required wall thickness to ensure sufficient thermal conductivity for blocks is up to 500 mm, while for bricks a similar masonry thickness of 2000 mm will be required. The consumption of mortar for laying the material will be 0.12 m3 for brick and 0.008 m3 for gas silicate blocks per 1 m2 of masonry.

Weight of one square meter the walls will be up to 250 kg for gas silicate material, and up to two tons of brick. In this case, an appropriate foundation thickness will be required for the load-bearing walls of the building under construction. Brickwork will require a foundation thickness of at least 2 meters, while for gas silicate blocks a thickness of only 500 mm is sufficient. The labor intensity of laying blocks is much lower, which will reduce labor costs.

Among other things, gas silicate blocks are much more environmentally friendly. The coefficient of this material is two points, bringing it closer to natural wood. At the same time, the environmental friendliness of bricks is at a level of 8 to 10 units.

Advantages and disadvantages of gas silicate blocks

Gas silicate blocks, the price of which will significantly reduce the cost of building a house, have the following number of undeniable advantages:

Light weight of finished blocks. A gas silicate block weighs 5 times less compared to a similar concrete block. This will significantly reduce delivery and installation costs.
High mechanical compressive strength. Gas silicate with an index of D500, indicating that its density is 500 kg/m3, demonstrates an indicator of up to 40 kg/cm3.

The thermal resistance indicator is 8 times higher than that of heavy concrete. Thanks to its porous structure, good thermal insulation performance is ensured.
Gas silicate blocks have heat-storing properties. They are able to release accumulated heat indoors, which will reduce heating costs.
Thanks to the porous structure, the degree of sound insulation is 10 times higher than that of brick.
The material does not contain any toxins and has good environmental performance.
Gas silicate is distinguished by its non-flammability and does not propagate combustion. It withstands direct exposure to flame for at least three hours, due to which the situation with the spread of fire is almost completely eliminated.
The vapor permeability of the blocks is significantly higher than that of competitors. It is believed that the material is able to “breathe” well, while creating a comfortable indoor microclimate.

However, gas silicate blocks are currently not capable of delivering a crushing blow to all competitors. This material also has significant disadvantages:

Gas silicate has low mechanical strength. When a dowel is screwed into it, it begins to crumble and crumble, and is not able to provide effective retention. Roughly speaking, it is still possible to hang a clock or a picture on a wall made of gas silicate blocks. But the shelf may already collapse, since the fasteners can simply slide out of the wall.
The blocks do not have good frost resistance. Despite the manufacturer’s declared cycle of 50 years for brands with increased strength, there is no reliable information about the durability of blocks of the D300 brands.
The main disadvantage of gas silicate is its high moisture absorption. It penetrates the structure, gradually destroying it and the material loses its strength.
From the above disadvantage comes the following: the accumulation and absorption of moisture leads to the appearance of fungus. IN in this case porous structure serves good condition for its distribution.
The material can shrink significantly, as a result of which cracks often appear in the blocks. Moreover, after just two years, cracks can appear on 20% of the stacked blocks.
It is not recommended to apply cement-sand plasters. They can simply fall off the wall. Recommended by many sellers gypsum plaster neither is effective means. When applied to a wall made of gas silicate blocks, it is not able to hide the seams between the blocks, and when cold weather sets in, noticeable cracks appear on it. This occurs due to temperature differences and changes in the tightness of the material.
Due to its high moisture absorption, the plaster will require at least two coats. Moreover, due to strong shrinkage, the plaster will become covered with cracks. They will not affect the tightness, but will greatly disturb the aesthetic component. The gypsum mixture adheres well to gas silicate blocks, and despite the appearance of cracks, it does not come off.

How gas silicate blocks are produced

It is more expedient to buy gas silicate blocks from those dealers who represent the products famous manufacturers. Modern high-quality equipment on factory lines allows for proper control over the quality of produced gas silicate blocks, thanks to which the buyer is confident in the durability of the purchased products.

The production process itself is divided into several stages, and, characteristically, each of them is fully automated. This eliminates interference human factor, on which the quality of products often depends. Especially on Fridays and Mondays. Anyone who has worked in production will understand.

Lime, sand and gypsum are crushed, which forms the basis for the production of blocks. By adding water, the sand is ground to a liquid mixture. It is sent to a mixer, into which cement, gypsum and lime are added. Next, the components are mixed, and during this process an aluminum suspension is added to them.

After all the components have been thoroughly mixed together, the mixture is poured into molds, which are moved to the maturation zone. When exposed to a temperature of 40°C for four hours, swelling of the material occurs. In this case, hydrogen is actively released. Thanks to this, the final mass acquires the necessary porous structure.

Using a turning grip and a cutting machine, the blocks are cut into required sizes. At the same time, automation controls accurate and defect-free cutting of products.

Following this, the blocks are sent to an autoclave to gain their final strength. This process takes place in a chamber exposed to a temperature of 180°C for 12 hours. In this case, the steam pressure on the gas silicate should be at least 12 atmospheres. Thanks to this mode, the finished blocks gain the optimal value of final strength.

Thanks to the crane-divider and equipment for final quality control, the blocks are laid for their subsequent natural cooling. After that, possible contamination is removed from the blocks on an automatic line and the blocks are packaged and labeled.

What is noteworthy is that the production process is waste-free, since at the time of cutting, still at the hardening stage, the waste of the raw mass is sent for recycling, adding material to other blocks.

Pallets with packaged gas silicate blocks receive their own technical passport with detailed information physical properties and technical characteristics of the product, so that the buyer can verify compliance with the declared characteristics.

Further work is up to dealers and marketers, on whom the success of product sales will depend.

Gas silicate blocks are in great demand in residential and industrial construction. This building material is superior to concrete, brick, natural wood etc. It is made from environmentally friendly raw materials and is lightweight, fire-resistant, easy to operate and transport. Application of this lightweight material allows you to reduce the cost of arranging a heavy reinforced foundation and thereby reduce the cost of building construction.

What are gas silicate blocks

Gas silicate block is a lightweight and durable wall material made from cellular concrete. The products have a porous internal structure, which has a positive effect on their heat and sound insulation properties. Such building materials can be used in various areas of the construction industry - for the construction of country and country houses, car garages, utility buildings, warehouse complexes, etc.

How gas silicate blocks are produced

There are two main technologies for the production of gas silicate building blocks.

Non-autoclave. With this production method, the working mixture hardens under natural conditions. Non-autoclaved gas silicate blocks have a lower cost, but have some important differences from autoclaved ones. Firstly, they are less durable. Secondly, when they dry, shrinkage occurs almost 5 times more intense than in the case of autoclaved products.
Autoclave. Autoclave production of gas silicate requires more energy and material resources, which increases the final cost of the products. Manufacturing is carried out at a certain pressure (0.8-1.2 MPa) and temperature (up to 200 degrees Celsius). The finished products are more durable and resistant to shrinkage.

Types of blocks

Depending on the density, composition and functional purpose, gas silicate blocks are divided into three main categories.

Structural. They have high strength characteristics. The density of the products is at least 700 kg/m3. They are used in the construction of high-rise buildings (up to three floors). Capable of withstanding large mechanical loads. Thermal conductivity is 0.18-0.2 W/(m °C).
Structural and thermal insulation. Blocks with a density of 500-700 kg/m 3 are used when constructing load-bearing walls in low-rise buildings. They are distinguished by a balanced ratio of strength and thermal insulation characteristics[(0.12-0.18 W/(m °C)].
Thermal insulation. They are distinguished by increased thermal insulation properties [(0.08-0.1 W/(m ° C)]. Due to their low density (less than 400 kg/m 3), they are not suitable for creating load-bearing walls, therefore they are used exclusively for insulation.

Dimensions and weight

Wall blocks made of gas silicate have standard dimensions of 600 x 200 x 300 mm. The overall dimensions of the semi-blocks are 600 x 100 x 300 mm. Depending on the manufacturing company, product sizes may vary slightly: 500 x 200 x 300, 588 x 300 x 288 mm, etc.

The mass of one block depends on its density:

structural blocks weigh 20-40 kg, half-blocks - 10-16 kg;
structural and thermal insulation blocks and semi-blocks - 17-30 kg and 9-13 kg, respectively;
heat-insulating blocks weigh 14-21 kg, half-blocks - 5-10 kg.

Composition of gas silicate blocks

Gas silicate is an environmentally friendly building material that is made from non-toxic raw materials of natural origin. The blocks contain cement, sand, lime and water. Aluminum chips are used as a foaming agent, which helps to increase the void ratio of the blocks. Also in the production of the material, a surfactant is used - sulfonol C.

Material characteristics

Gas silicate building blocks have the following characteristics.

Heat capacity. Products manufactured using autoclave technology have a thermal conductivity coefficient of 1 kJ/(kg °C).
Thermal conductivity. Structural and thermal insulating gas silicate has an average thermal conductivity of about 0.14 W/(m °C), while for reinforced concrete this parameter reaches 2.04.
Sound absorption. Gas silicate blocks significantly reduce the amplitude of external noise; the sound absorption index for this material is 0.2.
Frost resistance. Material with a density of 600 kg/m 3 can withstand up to 35 freezing and thawing cycles (which corresponds to the F35 index). Products with a higher density are assigned frost resistance class F50.

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 of the same size. 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.

How critical are the shortcomings?

Like any other building material, gas silicate has some disadvantages.

Low safety factor. Material with low density (300-400 kg/m3) has relatively low strength characteristics. Therefore, during construction it is imperative to carry out work on reinforcing the walls.
Smooth surfaces. The front parts of gas silicate blocks have a smooth surface with a low roughness coefficient. Because of this, adhesion with finishing materials, which complicates the process of finishing walls with plaster and other coatings.
Low moisture resistance. Due to the increased porosity, the material is sensitive to high humidity. Water and water vapor penetrate the internal micropores and, when frozen, increase in volume, destroying the blocks from the inside. Therefore, walls made of gas silicate require additional waterproofing.

Where are gas silicate blocks used?

Gas silicate blocks are used in residential and industrial construction. This material is used not only for the construction of load-bearing elements of buildings, but also to increase thermal insulation, as well as to protect utility networks(in particular, heating ones).

The scope of application of gas silicate is determined by its characteristics, primarily density.

Products whose density is 300-400 kg/m 3 have a low safety margin, so they are used primarily for wall insulation.
Gas silicate with a density of 400 kg/m 3 is suitable for the construction one-story houses, garages, service and outbuildings. Due to its higher strength, the material is able to withstand significant loads.
Blocks with a density of 500 kg/m 3 are optimal in terms of strength and thermal insulation properties. They are often used to build cottages, country houses and other buildings up to 3 floors high.

The most durable are gas silicate blocks with a density of 700 kg/m 3. They are used for the construction of high-rise residential and industrial buildings. But due to the increased density, the porosity coefficient of the material decreases and, consequently, its thermal insulation properties. Therefore, walls built from such blocks require additional insulation.

The process of building and testing blocks.

Gas silicate blocks are a type of wall material made of cellular concrete.

In prepared concrete mixture special pore-forming additives are added. In the 19th century, ox blood was mixed in to achieve this effect.

In the early 30s, the Soviet builder Bryushkov drew attention to a plant growing in Central Asia - soap root.

The cement solution, when mixed with the foam of this plant, gained the ability to foam and increase in volume, and when hardened, it retained the resulting porous structure.

Then, various chemical gas-forming additives began to be added. Unfortunately, we have not patented this production method. artificial stone. This was done by the Swedish architect Ericsson in 1924.

Composition of gas silicate blocks

Blocks made from gas silicate mixtures are a wall material that allows you to create a healthy indoor microclimate, as it has good diffusion characteristics. That is, the building “breathes”, which eliminates the appearance of mold. What initial components are taken to make blocks?

The aerated concrete mixture, according to SN 277-80 “Instructions for the manufacture of products from cellular concrete” consists of:

Portland cement, manufactured in accordance with GOST 10178-76, with a calcium silicate content of at least 50%., tricalcium aluminate not more than 6%. The addition of tripoli is not allowed.
Sand must meet the requirements of GOST 8736-77, clay and silt inclusions no more than 2%, quartz content no less than 85%.
Water with technical requirements according to GOST 23732-79.
Calcium lime-lime must comply with GOST 9179-77, and be at least grade 3. Additional characteristics: extinguishing speed 5-15 min., “burnout” - no more than 2%, CaO + MgO content - no less than 70%.
The gas generator used is aluminum powder PAP-1 or PAP-2
Surfactant (surfactant) – sulfonol C.

Types and characteristics

According to the manufacturing method, gas silicate is divided into:

Non-autoclaved – the working mixture hardens under natural conditions. This method can produce cheaper material, but such blocks will have worse strength characteristics, and drying shrinkage is five times higher than that of an autoclave product.
Autoclaved — blocks with increased strength and shrinkage upon drying. Autoclave production energy-intensive and technologically advanced. The steaming of the produced gas silicate takes place at a pressure of 0.8-1.2 MPa and a temperature of 175-200ºС, which can be afforded large enterprises. You need to remember this when purchasing gas silicate blocks.

Calculating the percentage of ingredients in the composition aerated concrete mixture, you can obtain different characteristics of gas silicate. For example, by adding Portland cement, we increase strength and frost resistance (by reducing the number of “dangerous pores”), but worsen the thermal conductivity of the product.

Main physical and mechanical properties blocks:

1. Based on density, gas silicate blocks are divided into the following types:

Structural: grade D700 and higher. They are used for the construction of high-rise buildings - up to three floors.
Structural and thermal insulation: brands D500, D600, D700. Can be used to construct partitions and load-bearing walls of low-rise buildings. However, it should be noted that some manufacturers’ D500 brand products are classified as thermal insulation types.
Thermal insulation: no higher than grade D400. This type of gas block is intended for the thermal insulation contour of load-bearing walls built from more durable materials.

It should be mentioned that professional practitioners advise: use wall construction with load-bearing frame, if it is assumed that the future house will have more than two floors. It's probably worth heeding this advice.

2. The thermal conductivity indicator depends on the purpose of the block:

Structural grades have a thermal conductivity of 0.18 to 0.20 W/m·°C, which is lower than those of clay bricks.
Structural and thermal insulation – from 0.12 to 0.18 W/m·°C.
Thermal insulation - from 0.08 to 0.10 W/m °C. If we compare it with the thermal conductivity of wood (0.11 to 0.19 W/m °C), then the primacy will go to the gas block.

It must be remembered that this indicator refers to completely dry material. When wet, this characteristic worsens.

3. The frost resistance of gas silicate blocks depends on the characteristics of the cellular structure, which is divided into three classes:

Reserve – pore volume with a diameter of more than 200 microns
Safe – pore volume with a diameter of less than 0.1 microns
Hazardous – from 200 to 0.1 microns

If the ratio of the reserve volume to the dangerous volume is more than 0.09, then the aerated concrete block will have high frost resistance. The frost resistance of gas blocks is quite high. It is equal to: 15, 25, 35 cycles. Some manufacturers claim 50, 75 and even 100 cycles. Like, for example, the Saratov plant, which produces YTONG blocks.

But we must take into account that GOST 25485-89 standardized brands for frost resistance starting from D500, and this figure was no higher than F35.

Therefore, it is advisable to be careful about the frost resistance of their products declared by manufacturers. One might wonder about the meaning of the above relationship.

Dimensions and weight

Based on their intended purpose, gas silicate blocks are divided into:

Wall block. Standard size of gas silicate block: 600×200×300 mm (length; depth; height)
Wall semi-block. Its size: 600×100×300 mm.
The dimensions of gas silicate, depending on the manufacturer, can vary significantly: 500×200×300 mm; 588×150×288 mm; 588×300×288 mm; 600×250×400 mm; 600×250×250 mm, etc.

How much does a gas silicate block weigh? Its weight, naturally, depends on the density and volumetric characteristics of the gas silicate:

The weight of a structural wall block is 20 kg - 40 kg. Half block – from 10 kg to 16 kg.
The weight of the structural and thermal insulation block is from 17 kg to 30 kg. Half block – from 9 kg to 13 kg.
The weight of the thermal insulation block ranges from 14 kg to 21 kg. Half block – from 5 kg to 10 kg.

Advantages and disadvantages

Advantages of gas silicate blocks:

Low density (light weight), exerts little pressure on the foundation of house construction. Allows you to reduce construction time, reduce labor and transportation costs.
Low thermal conductivity. It is three times lower than that of clay brick.
High sound insulation. It is 10 times higher than that of brickwork.
The geometry of the products is almost ideal, which allows masonry to be carried out using special adhesives.
Relatively low cost.
Excellent fire-resistant properties.
Create a healthy indoor microclimate.

Disadvantages of gas silicate blocks:

1. Construction of a house from this wall material requires highly qualified workers with experience working with gas silicate:

If we don’t want to get a wall with cracks, we need a high-quality foundation. It is important that at the base (or base), the horizontal deviations are no more than 3 mm for a length of 2 m.
Laying on adhesives must be carried out with special care: a gap in the adhesive seam is unacceptable, otherwise we will get natural ventilation through the walls, and, contrary to expectations, the house will be cold. You should not make seams less than 3-5 mm thick.
Expensive interior decoration. Plastering must be done over a mesh (fiberglass) so that cracks do not appear. The plaster layer should be no more than 4-5 mm.

2. The need to finish the facade not only because of the unsightliness of the masonry, but also because gas silicate absorbs moisture well. Due to this feature, it is not recommended to use it in areas where the humidity is more than 60%.

3. A wall made of aerated concrete does not hold heavy hanging objects well.

How much does a gas silicate block cost?

Depending on the manufacturer and brand, the price for 1 m3 (28 pieces - 600x200x300) is:

Wall, structural and thermal insulation block from RUB 3,500. up to 3800 rub.
Structural - about 3800-4000 rubles.

The price for 1 piece of standard size gas silicate block for structural and thermal insulation purposes ranges from 120 to 140 rubles.

Gas silicate blocks are construction material universal meaning. It is an artificial porous stone. This structure is formed through a natural chemical reaction between aluminum and lime. During the reaction, these two components break down and form hydrogen.

In conditions of constant rise in energy prices, the need for building materials with high thermal characteristics is increasing. To reduce heat loss in modern projects aerated concrete and gas silicate blocks are increasingly being used - materials of the heat-insulating class cellular concrete. They are often confused due to their common properties and the same scope of application. Even specialists cannot always immediately tell a potential customer which material is in front of him - gas silicate or aerated concrete, which is better, what is the difference between them and whether there is any at all. Partly, the confusion is caused by the manufacturers themselves when they define aerated concrete as a type of gas silicate or vice versa.

What is the difference between aerated concrete and gas silicate? In particular, when producing aerated concrete, natural hardening of the block in the open air is allowed; for gas silicate, autoclave ovens are a prerequisite. In addition, for aerated concrete blocks the main binding component is cement, while for silicate analogues it is lime. The use of different components affects the color of the finished blocks.

If we talk about specific characteristics, you can notice the following differences:

Gas silicate blocks have a uniform distribution of hollow cells, which ensures high strength.
The weight of aerated concrete blocks is much greater, which requires a reinforced foundation during construction.
In terms of thermal insulation, gas silicate blocks outperform aerated concrete blocks.
Aerated concrete absorbs moisture better, which provides a greater number of freezing cycles.
Gas silicate blocks have a more consistent geometry, which makes the finishing of wall structures easier.

Externally finished products distinguished by color: gas silicate or autoclaved aerated concrete almost white, grey colour typical for non-autoclaved aerated concrete.

The average values for each parameter are shown in the following table:

In terms of durability, the materials are identical and can last more than 50 years.

If you answer the question: “What is better, aerated concrete or gas silicate?”, gas silicate blocks have much more technical advantages. However, manufacturing technology forces an increase in the cost of finished products, so aerated concrete blocks are cheaper. Therefore, those who want to build a house from high-quality and modern material choose aerated silicate; those who want to save money on construction give preference to aerated concrete.

In this case, it is necessary to take into account the region of application: in areas with high humidity air, service life gas silicate blocks is noticeably reduced.

Composition and production technology of gas silicate blocks

The mixture for the production of gas silicate blocks has the following composition:

binder (Portland cement according to GOST 10178-76, calcium lime (according to GOST 9179-77);
silicate or silica filler ( quartz sand with 85% content of quartz, fly ash, etc.);
lime, with a content of magnesium and calcium oxides of more than 70%, and a slaking speed of up to 15 minutes;
technical water;
gas-forming additive (aluminum powder and others).

Gas silicate 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 in a ratio of 0.62:0.24 can act as fillers. We should also talk about the additives that give gas silicate 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 gas silicate. 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

The cellular structure makes up almost 85% of the volume of the entire block, so this material It 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.

IN metal containers or forms the basic 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.

Gas silicate blocks are manufactured only using the autoclave method. Aerated concrete blocks can be produced both by autoclave and non-autoclave methods (natural hardening of the mixture):

Autoclave processing. This stage significantly improves the technical characteristics of gas silicate. Here for 12 hours at high blood pressure steam treatment is carried out, 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). Its specific 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 there is no need for special equipment. The strength of blocks in this production does not exceed 12 kgf/m².

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 gas silicate are distributed extremely evenly, which affects the precise compliance of the material with the given parameters.

Gas silicate blocks: characteristics

Density of gas silicate blocks

The brand and density of gas silicate blocks is indicated in the marking and determines the purpose of the block:

structural gas silicate blocks – D1000-1200, have a density from 1000 to 1200 kg/m3;
structural and thermal insulation blocks – D500-900, have a density of 500-900 kg/m3;
thermal insulation D300-D500, the density of their materials is 300-500 kg/m3.

Blocks of different densities are easy to distinguish from each other visually.

There are several classifications of gas silicate blocks with certain technical characteristics. Today during construction work The following grades of this material are used. The best option For low-rise construction- gas silicate block d500 and gas silicate block d600.

The digital designation of the brands listed earlier shows the density of the material. In particular, the d500 gas silicate block has a density of 500 kg/m³.

Gas silicate block d600

Gas silicate block d600 is used in the construction of load-bearing walls of a house. It is also recommended for use in the construction of ventilated facades, which are well attached to blocks of such density. Gas silicate block d600 has a strength of 2.5-4.5 MPa and has a thermal conductivity of 0.14-0.15 W/(m°C)

Gas silicate block d500

Gas silicate block d500 is most popular for low-rise (up to 3 floors) construction. This variety is also used in monolithic construction. Its parameters are 2-3 MPa (strength) and 0.12-0.13 W/(m°C) (thermal conductivity).

When building a house higher than three floors, you should give preference to gas silicate with a marking higher than D600 and additionally insulate the walls. Based on the value of the thermal conductivity coefficient, we can conclude that the d500 gas silicate block is 15-17% warmer than the d600 gas silicate block.

Gas silicate block d400

This type is used for arranging insulation and for working with openings during the construction of multi-storey buildings using the monolithic method. The D400 brand is also popular in private construction. With high strength, it has great heat-insulating properties. These indicators are in the range of 1 MPa to 1.5 MPa (strength), 0.10-0.11 W/(m°C) (thermal conductivity).

Gas silicate block d300

Brand D350 can only be used as insulation. This is a rather rare brand on the domestic market, due to its fragility. Strength is in the range of 0.7-1.0 MPa. But it differs in thermal conductivity, which is 0.08-0.09 W/(m°C).

Thermal conductivity of gas silicate blocks

Depending on the proportions of the starting ingredients, you can get a product with different performance characteristics. The thermal conductivity coefficient of a gas silicate block depends on its density and is determined by the marking: D300, D400, D500, D600, D700.

The thermal conductivity of gas silicate depends on a number of factors:

Dimensions building block. The greater the thickness wall block, the higher its thermal insulation properties.
Ambient humidity. Material that has absorbed moisture reduces its ability to store heat.
Structure and number of pores. Blocks that have in their structure a large number of large air cells, have increased thermal insulation properties.
Density of concrete partitions. Higher density building materials retain heat less well.

Thermal conductivity table for gas silicate blocks

Types of gas silicate blocks

By appearance There are several configurations of the gas silicate block. The classification is based on the purpose of the block.

Smooth (straight) gas silicate block with hand grip

An absolutely smooth rectangular gas silicate block with recesses for gripping by hand. The gripper is easy to use because it allows you to easily move the blocks. The presence of grip handles increases glue consumption, since the technology of laying gas silicate blocks involves filling all voids during the work process.

Wall gas silicate blocks with flat edges

The usual rectangular shape reduces glue consumption, but creates difficulties in moving the block. In practice, when constructing load-bearing walls where larger blocks are used, preference is given to a block with a grip.

Gas silicate blocks for partitions

They are blocks with flat edges. Partition blocks are thinner and lighter in weight. It's convenient to work with them.

You can cut out any designs on straight blocks using a screwdriver. But such decor is more likely to be used in finishing a site with the remains of blocks from construction rather than in the construction itself, since it is advisable to protect gas silicate with external finishing material.

Tongue-and-groove gas silicate wall blocks

The formation of a tongue-and-groove connection system, in terms of production complexity, is classified as a high-tech block processing. Therefore, they are more expensive. However, it is justified because: it increases the speed of work, reduces glue consumption (vertical joints do not require gluing), and it becomes possible to eliminate cold bridges in places of vertical joints.

If the house will not undergo external finishing. It is better to apply a thin layer of glue to the joint from the front side of the masonry. This will provide additional insulation to the seam.

U-shaped gas silicate blocks

The purpose of U-shaped blocks is to install hidden construction elements (for lintels and monolithic belts). According to the technology, masonry of walls made of gas silicate blocks requires mandatory reinforcement of the first and every fourth of the subsequent rows. It is precisely in order to conveniently hide the reinforcement that the voids in the U-shaped blocks are intended. After laying the reinforcing metal, the space must be filled with concrete mortar or glue. In this case, you should use more cheap material for filling.

What are the sizes of gas silicate blocks?

Of course, manufacturers produce gas silicate blocks of different sizes. However, most enterprises try to follow the established standards of GOST No. 31360 of 2007. Here are the dimensions of the finished products:

250*250*600.
250*400*600.
500*200*300.
600*100*300.
600*200*300.

It is important to understand that according to GOST, deviations in length and diagonal values are allowed, which classify finished products into the 1st or 2nd category.

Deviations in the dimensions of gas silicate blocks reduce installation time due to the absence of the need for grinding and adjustment.

Thickness of gas silicate blocks: 200, 250, 300, 350, 375, 400, 500 mm;
The thickness of the partition blocks is 100-150 mm;
Length of gas silicate blocks: 600, 625 mm;
Height of gas silicate blocks: 200, 250, 300 mm;
Weight of gas silicate blocks: 14-34 kg;
In 1 cubic meter from 13 to 33 pcs. (depending on thickness);
Consumption per 1 sq.m. walls is 6.7-7 pcs.

The exact parameters are shown in the tables below:

Dimensions of a U-shaped gas block Dimensions of a gas silicate block for walls (LxWxH) different manufacturers and the number of pieces on the pallet.

Number of blocks in a pallet

Weight of gas silicate block

The structural mass of the block varies depending on the density finished product. Judging by the markings, we can distinguish the following weight:

D400. Weight 5-21 kg.
D500/D600. Weight – 9-30 kg.
D700. Weight – 10-40 kg.

In addition to density, the fundamental factor in weight change is the overall size of the finished block.

Pros and cons of gas silicate blocks

Like any building material, gas silicate blocks have strong and weak sides. TO positive characteristics The following points can be mentioned:

Gas silicate concrete belongs to the category of non-combustible materials and is able to withstand exposure open flame up to 5 hours, without changing shape and properties.
Large dimensions ensure rapid construction of wall structures.
The blocks have a specific low weight, which significantly simplifies the work process.
Only used in production natural materials, therefore gas silicate blocks are environmentally friendly.
The porous structure provides high thermal insulation values for rooms.
The material is easy to process, which helps to build walls with complex geometries.

The disadvantages include the following:

They absorb moisture well, which reduces their service life.
Application for adhesion of special adhesive compositions.
Mandatory external finishing.

It is worth noting that gas silicate blocks require a solid foundation. In most cases, a reinforcing belt is required.

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