Efficiency of gas silicate blocks in the construction of low-rise buildings. gas silicate block

Gas silicate building blocks are a building material of universal value. It is an artificial porous stone. This structure is formed by a natural chemical reaction between aluminum and lime. During the reaction, these two components decompose and form hydrogen.

Gas silicate blocks undergo heat treatment (up to + 190 ° C) under a pressure of 10-12 bar. Thanks to this material, additional strength is given, and thermal conductivity and frost resistance are improved.

was developed in Sweden at the beginning of the last century, but gained popularity only recently. It has practically not undergone changes over time, which indicates its convenience, simplicity and reliability.

Types of gas silicate blocks

All gas silicate blocks can be divided into three types:

aerated concrete is an artificial stone. Closed air cells no more than 3 mm in diameter are distributed in its array. The main components are: sand, cement, a set of gas-forming components. Air pores significantly increase its thermal conductivity.

foam concrete It is a material similar to aerated concrete. The difference is in the production method. Cells are formed due to the introduction of foaming additives. The main components are: quartz, lime and cement.

gas silicate- building material formed by autoclave hardening. Its components are: crushed sand and lime, aluminum powder. Lighter weight and better thermal conductivity.

Video about what you need to know about gas silicate blocks as a building material:

Classification by scope

Wall blocks designed for laying walls with minimal seams. In the manufacturing process of this material, new technologies are used, which include the use of cement, quartz sand, water and lime. Aluminum powder is used to form pores.

Depending on the density of the material, they can be used both for insulation (density 350 kg/m3) and for low-rise construction (400-500 kg/m3). Wall blocks are larger in size, which reduces material and labor costs.

Today it is a very common occurrence. Such a high popularity of gas silicate blocks is due to their low cost and thermal conductivity, which makes it possible to obtain energy-efficient buildings.

Partition blocks can be used for the construction of partitions and walls. Blocks of 10 cm thickness are suitable for the internal walls of the apartment. The height and width of 100 mm blocks are not significant.

The average dimensions of partition blocks for interior walls are 200 * 200 * 400mm, there are also very thin blocks with a thickness of 50 mm.

They are easy to install and have a number of advantages:

• Good sound and heat insulation properties;
• Profitability;
• Light weight;
• Small cost.

In addition to the advantages of these blocks, there are also disadvantages:

• Difficulty in processing;
• Low strength;
• High costs in further operation.

This is only a small part of such a building material as gas silicate. See this article for a more detailed list.

Types of blocks depending on the size and strength categories

• Dry laying with glue. Blocks with 1 accuracy category allow deviations: in sizes up to 1.5 mm; in the straightness of faces and ribs - up to 2 mm; broken corners - up to 2 mm; rib breakage - no more than 5 mm. (Standard size of gas silicate block 600x400x200)
• Glue laying. Blocks of the 2nd accuracy category can differ in size up to 2 mm, have deviations from straightness and squareness of edges and faces up to 3 mm, broken corners - up to 2 mm, and edges - up to 5 mm.
• Laying for mortar. 3 accuracy category can have deviations from block dimensions up to 3 mm, squareness and straightness - up to 4 mm, broken edges - up to 10 mm, and corners - up to 2 mm.

The tongue-and-groove silicate blocks, unlike smooth surfaces, have hand grips. The scope of their application: monolithic-frame construction, as well as the construction of multi-storey buildings.

When laying, they have a thermal lock function and a guiding function. This erection system is able to save on the adhesive solution.

The picture shows tongue-and-groove gas silicate blocks

Composition of gas silicates

The main component in the production of gas silicate blocks is lime. And therefore, increased requirements are imposed on it: activity and purity of the composition. The end result directly depends on the quality of this component.

In addition to lime, the composition of gas silicate blocks includes a mixture of quartz sand, water, cement and aluminum powder. The last component reacts with calcium hydroxide, carrying out the process of gas formation. Gas bubbles begin to form even at the initial stages of production up to the placement of blocks in autoclaves.

In many ways, the composition and production technology determines the future and operational properties of gas silicate blocks.

Grades of gas silicates

Structural grades reflect the purpose of gas silicate blocks:

• D1000- D1200 - designed for the construction of residential, industrial and public buildings and structures;
• D200-D500 - for insulation of building structures;
• D500-D900 - structural and heat-insulating products;
• D700 - autoclaved wall products.

Depending on the density of the material, gas silicate blocks can be used for the construction of low-rise buildings and multi-storey buildings (up to 9 floors) and are distinguished by the following brands:

• 200-350 - heat-insulating materials;
• 400-600 - for load-bearing and non-bearing walls in low-rise construction;
• 500-700 - for buildings and structures with a height of not more than 3 floors;
• 700 and above - for multi-storey construction with reinforcement.

Regardless of the brand of blocks, before embarking on the construction of gas silicate walls, you need to find out the features and.

Gas silicate or foam block

Both of these building materials have the same origin: concrete mortar and porous structure. There are differences in the technology of the appearance of bubbles. During the production of foam concrete, bubbles are formed by the interaction of aluminum dust and lime, which release hydrogen.

And the porous structure of gas silicates is achieved by adding a special foaming agent. Both materials harden faster than the air leaves their structure. If in the first variant the bubbles try to leave the mixture and rise up, then in the other case, they are held by the foaming agent.

When its action stops, the bubbles burst and compact the structure. Therefore, both materials differ in hygroscopicity. Moisture is easier to get into foam concrete than into gas silicate.

The foam block, unlike gas silicate, has a perfectly smooth surface. It is more difficult for moisture to penetrate into it. If we compare blocks with the same strength, then gas silicate will have less weight. This is due to its greater porosity.

Table 1

Gas block and gas silicate

The gas block is an artificial stone having cells with a diameter of 1 to 3 mm. They are evenly distributed throughout the structure of the material. It is the degree of uniformity of these bubbles that affects the quality of the final material. In the production of a gas block, cement with autoclave or natural hardening is the basis.

Gas silicate is a material based on lime. In addition to it, the composition includes: sand, water and gas-forming additives. The blocks are autoclaved. The mixture for gas silicate is poured into a mold and undergoes furnace heat treatment, after which the finished block is cut by a string into smaller blocks of the required size.

Gas blocks have a lower noise insulation coefficient. If the gas silicate absorbs moisture and its structure suffers from this, then the gas block passes it through itself, creating a comfortable microclimate in the room.

Gas silicate blocks due to uniform porosity are more durable. And they are more expensive than less durable gas blocks.

table 2

Gas silicate blocks or expanded clay blocks

Important advantages of gas silicate blocks are safety: environmental and technical. The low coefficient of thermal conductivity allows you to withstand contact with natural phenomena and fire, and at the same time retain heat even in severe frosts.

The absence of radioactive substances, heavy metals and other components hazardous to life and health in the composition of gas silicate blocks allows you to build any buildings without fear for your health. The strength of the blocks makes it possible to build 2-3 storey buildings.

But, despite its advantages, gas silicate has a competitor - expanded clay concrete. Its tongue-and-groove structure makes it possible to lay out walls without seams. Such construction eliminates the occurrence of cold bridges and saves the adhesive solution.

The porous structure of expanded clay blocks retains heat better in the room than gas silicate blocks. And in terms of frost resistance, it is 15 cycles more than that of a competitive material. The cost of these materials is almost equal.

Gas silicate and expanded clay blocks have almost equal physical and chemical properties. They are out of competition in front of wood and brick - this is also shown by statistics on developers. Gas silicate blocks are more in demand in the building materials market due to their availability and low cost.

Aerated concrete is a light porous material that has a rather low strength class. Yes, in terms of compressive strength, aerated concrete loses to almost all building materials. But, it is very important to understand that even the available strength is enough with a margin for the construction of a two / three-story house. The main thing is to choose the required density of aerated concrete, which will provide the desired strength for the project.

For the construction of load-bearing walls, aerated concrete with a density from D300 to D700 is used, and the most popular are the middle ones - D400 and D500, as they have optimal strength and heat-saving properties.

Modern plants for the production of autoclaved aerated concrete produce very high quality and homogeneous aerated concrete, the strength class of which is much higher than that of obsolete plants. For example, the best aerated concrete with a density of D400 has a B2.5 class, while the cheaper one only reaches B1.5.

The numerical value of class B2.5 indicates that a square millimeter of aerated concrete can withstand a load of 2.5 N (Newton). That is, a square centimeter is guaranteed to withstand a load of 25 kg.

The very concept of aerated concrete strength class” means that each block brought from the factory will have a strength not less than that declared by the manufacturer. That is, it is a guaranteed warranty strength, below which it should not be.

Aerated concrete grade is the average strength value obtained by testing several blocks from a batch. That is, six blocks were taken for a sample, and their strength indicators were respectively: 31, 32, 32, 33, 35, 35 kg/cm2. The average value obtained is 33 kg/cm2. Which corresponds to the brand M35.

Strength grade- this is an average value, and the strength class is a secured value, below which it cannot be.

To determine the required strength class of aerated concrete, it is necessary to know the design resistance of the masonry and the bearing capacity of the wall section.

The bearing capacity of the wall will be about 5 times less than the compressive strength of the material. This is due to various factors that reduce the bearing capacity of the masonry, and safety margins according to SNiP.

The main factors affecting the load-bearing capacity are: wall height, wall thickness, and load application area (eccentricity). The higher and thinner the wall, the more it can bend under load, which reduces its design bearing capacity.

The load application zone (eccentricity) also greatly affects the strength of the structure, because if the floor slab rests on the wall only at the edge, and does not reach the center of the wall, an eccentric compression is obtained, leading to a bending moment.

Output. Aerated concrete can be of various densities from D300 to D700 and different strength classes, from B1 to B5, which makes it possible to build houses of various heights and complexity from it. If the strength of aerated concrete is not enough, reinforced concrete inclusions are used, similar to reinforced concrete beams, lintels, armored belts and armored frames.

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

Special pore-forming additives are added to the prepared concrete mix. In the 19th century, bovine blood was mixed in to achieve this effect.

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

The cement mortar, when mixed with the foam of this plant, acquired the ability to foam and increase in volume, and when solidified, it retained the resulting porous structure.

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

Composition of gas silicate blocks

Blocks of gas silicate mixtures are a wall material that allows you to create a healthy microclimate in the room, as it has good diffuse characteristics. That is, the building "breathes", which eliminates the appearance of mold. What initial components are taken for the manufacture of blocks?

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 no more than 6%. Tripoli addition 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 boiling 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%.
• A blowing agent is used - aluminum powder PAP-1 or PAP-2
• Surface-active substance (surfactant) - sulfonic acid.

Types and characteristics

According to the method of manufacture, gas silicate is divided into:

• non-autoclave - the working mixture hardens in natural conditions. This way you can get cheaper material, but such blocks will have worse strength characteristics, and shrinkage during drying is five times higher than that of an autoclaved product.
• autoclaved - blocks with increased strength and shrinkage upon drying. Autoclave production is energy-intensive and technologically advanced. The steaming of the gas silicate produced is carried out at a pressure of 0.8-1.2 MPa and a temperature of 175-200ºС, which large enterprises can afford. This must be remembered when purchasing blocks of gas silicate.

By calculating the percentage of ingredients in the composition of the aerated concrete mixture, it is possible to obtain various characteristics of the 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.

The main physical and mechanical properties of blocks:

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

• Structural: grades D700 and above. They are used for the construction of high-rise buildings - up to three floors.
• Structural and heat-insulating: grades D500, D600, D700. It can be used for partitions and load-bearing walls of low-rise buildings. True, it should be noted that the products of the D500 brand for some manufacturers belong to heat-insulating types.
• Heat-insulating: not higher than D400 grade. This type of gas block is designed for the heat-insulating contour of load-bearing walls built from more durable materials.

It should be mentioned that professional practitioners advise: use the construction of walls with a supporting frame if it is assumed that the future house will have more than two floors. You should probably heed this advice.

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

• Structural grades have thermal conductivity from 0.18 to 0.20 W / m ° C, which is lower than those of clay bricks.
• Structural and heat-insulating - from 0.12 to 0.18 W / m ° С.
• Heat-insulating - from 0.08 to 0.10 W / m ° С. If compared with the thermal conductivity of wood (0.11 to 0.19 W / m ° C), then the championship will be for the gas block.

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

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

• Reserve - the volume of pores with a diameter of more than 200 microns
• Safe - pore volume with a diameter of less than 0.1 microns
• Dangerous - 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 or even 100 cycles. Like, for example, the Saratov plant, which produces YTONG blocks.

But it must be borne in mind that GOST 25485-89 normalized grades for frost resistance starting from D500, and this figure was not higher than F35.

Therefore, it is advisable to be wary of the frost resistance of their products declared by manufacturers. One may ask the meaning of the above relation.

Dimensions and weight

By purpose, gas silicate blocks are distinguished:

• Wall block. Standard size of gas silicate block: 600×200×300mm (length; depth; height)
• Wall 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; 600×250×250mm etc.

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

• The weight of the structural wall block is 20 kg - 40 kg. Semi-block - from 10 kg to 16 kg.
• The weight of the structural and heat-insulating block is from 17 kg to 30 kg. Semi-block - from 9 kg to 13 kg.
• The weight of the heat-insulating block is from 14 kg to 21 kg. Semi-block - from 5 kg to 10 kg.

Advantages and disadvantages

Advantages of gas silicate blocks:

• Low density (light weight), exerts little pressure on the building foundation. Allows you to reduce construction time, reduce labor and transportation costs.
• Low thermal conductivity. It is three times lower than that of clay bricks.
• High sound insulation. It is 10 times higher than that of brickwork.
• Almost perfect geometry of products, which allows laying on special adhesives.
• Relatively low cost.
• Excellent refractory properties.
• They create a healthy indoor climate.

Disadvantages of gas silicate blocks:

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

• If we do not want to get a wall in cracks, a high-quality foundation is necessary. It is important that at the base (or plinth), the horizontal deviations are no more than 3 mm for a length of 2 m.
• Laying on adhesives must be carried out with particular care: a gap in the adhesive joint is unacceptable, otherwise we will get natural ventilation through the walls, and, contrary to expectations, the house will be cold. Do not make seams less than 3-5 mm thick.
• Expensive interior decoration. Plaster without fail on a grid (fiberglass), so that cracks would 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 the gas silicate absorbs moisture well. In connection with this feature, it is not recommended to use it in areas where the humidity is more than 60%.

3. Aerated concrete wall does not hold heavy hanging objects well.

How much does a gas block cost?

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

• Wall, structural and heat-insulating block from 3500 rubles. up to 3800 rub.
• Structural - about 3800-4000 rubles.

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

Gas silicate blocks are a building material of universal value. It is an artificial porous stone. This structure is formed by a natural chemical reaction between aluminum and lime. During the reaction, these two components decompose and form hydrogen.

In the context of a constant rise in the price of energy carriers, the need for building materials with high thermal performance increases. To reduce heat loss in modern projects, aerated concrete and gas silicate blocks are increasingly used - materials of the class of heat-insulating cellular concrete. They are often confused due to their common properties and the same scope. 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 one at all. In part, the manufacturers themselves are confusing 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, in the manufacture of 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, for silicate analogues, 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 ones.
• Aerated concrete absorbs moisture better, which provides more freezing cycles.
• Gas silicate blocks have a more consistent geometry, as a result, the finishing of wall structures can be simplified.

Externally, finished products are distinguished by color: aerated silicate or autoclaved aerated concrete is almost white, gray color is 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: “Which is better, aerated concrete or gas silicate?”, Gas silicate blocks have much more technical advantages. However, manufacturing technology forces to increase 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 gas silicate, those who want to save on construction prefer aerated concrete.

At the same time, the region of application must be taken into account: in areas with high air humidity, the service life of 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 boiled lime (according to GOST 9179-77);
• silicate or siliceous filler (quartz sand with 85% quartz content, fly ash, etc.);
• lime, with a content of magnesium and calcium oxides of more than 70%, and a quenching 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 the ratio of 0.62:0.24 can act as fillers. Separately, it is worth talking about additives, which give the gas silicate its individual characteristics. Fine aluminum powder acts as an additive. All these components are thoroughly mixed, and under certain observed conditions, foaming of all these materials occurs. When aluminum powder reacts with lime, hydrogen is released. A huge amount of hydrogen bubbles released makes up the porous structure, which is the main distinguishing feature of gas silicate. In its structure, it 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 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 blowing agent (most often, it is a suspension of aluminum). Hydrogen formed by the reaction between aluminum paste (powder) and lime forms pores. Bubbles ranging in size from 0.6 to 3 mm are evenly dispersed throughout the material.

In metal containers or molds, the main chemical reactions take place. The mixture is subjected to vibration, which promotes swelling and setting. After hardening, all irregularities from the surface are removed with a steel string. The formation is divided into blocks, and then they are sent to the autoclave unit. The final calibration of the finished blocks is carried out by a milling machine.

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

1. Autoclave processing. This stage significantly improves the technical characteristics of gas silicate. Here for 12 hours at high 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 (not less than 28 kgf/m²). Its specific thermal conductivity is 0.09-0.18 W (m∙K), which makes it possible to build walls in one row (400 cm) in almost any climatic conditions, but excluding the northern regions.
2. Non-autoclave technology. It consists in the natural hardening of the mixture: moisturizing and drying in natural conditions. In this case, it is quite possible to make it yourself, since no special equipment is required here. The strength of blocks in such production does not exceed 12 kgf / m².

The first variety 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 coefficient of thermal conductivity is less. The pores inside such a gas silicate are distributed extremely evenly, which affects the strict compliance of the material with the specified 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 of 1000 to 1200 kg / m3;
• structural and heat-insulating blocks - D500-900, have a density of 500-900 kg / m3;
• heat-insulating D300-D500, the density of their materials is 300-500 kg / m.

Blocks of different density 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 is the d500 gas silicate block and the d600 gas silicate block.

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

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

Gas silicate block d500

The 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 above three floors, gas silicate with a marking above D600 should be preferred and the walls should be additionally insulated. Based on the value of the thermal conductivity coefficient, it can be concluded that the d500 gas silicate block is warmer than the d600 gas silicate block by 15-17%.

Gas silicate block d400

This variety is used for arranging insulation, for working with openings during the construction of multi-storey buildings using a 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 a heater. In the domestic market, this is a rather rare brand, 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 initial ingredients, a product with different performance characteristics can be obtained. The thermal conductivity coefficient of the gas silicate block depends on its density and is determined by marking: D300, D400, D500, D600, D700.

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

1. Building block dimensions. The greater the thickness of the wall block, the higher its heat-insulating properties.
2. Humidity of the environment. Material that absorbs moisture reduces the ability to store heat.
3. Structure and number of pores. Blocks that have a large number of large air cells in their structure have increased heat-insulating performance.
4. Density of concrete partitions. High-density building materials retain heat worse.

Table of thermal conductivity of gas silicate blocks

Types of gas silicate blocks

In appearance, several configurations of the gas silicate block are distinguished. The classification is based on the purpose of the block.

• Smooth (straight) gas silicate block with grip for hands

Absolutely smooth rectangular gas silicate block with recesses for gripping hands. The grip is comfortable to use, as it allows you to easily move the blocks. The presence of grip handles increases the consumption of glue, since the technology of laying gas silicate blocks provides for the filling of all voids during operation.

• Wall gas silicate blocks with flat edges

The usual rectangular shape reduces the consumption of glue, but makes it difficult to move the block. In practice, in the construction of load-bearing walls, where larger blocks are used, a block with a grip is preferred.

• Gas silicate blocks for partitions

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

On straight blocks, you can cut any pattern with a screwdriver. But such a decor is more applicable in finishing the site with the remains of blocks from the construction than in the construction itself, since it is desirable to protect the gas silicate with an external finishing material.

• Wall gas silicate blocks tongue-and-groove

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

If the house will not be exposed to exterior decoration. At the junction, it is better to apply a thin layer of glue from the front side of the masonry. This will provide additional seam insulation.

• U-shaped gas silicate blocks

The purpose of the U-shaped blocks is the installation of hidden building elements (for lintels and monolithic belts). According to technology, the laying of walls from gas silicate blocks provides for mandatory reinforcement, the first and every fourth of the subsequent rows. It is in order to conveniently hide the reinforcement that the voids in the U-shaped blocks are designed. After laying the reinforcing metal, the space must be filled with concrete mortar or glue. In this case, a cheaper filling material should be used.

What are the sizes of gas silicate blocks

Of course, manufacturers produce gas silicate blocks of various 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 the length and diagonal values ​​\u200b\u200bare allowed, which refer finished products to the 1st or 2nd category.

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

• Thickness of gas silicate blocks: 200, 250, 300, 350, 375, 400, 500 mm;
• The thickness of 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 pieces.

The exact parameters are shown in the tables below:

Dimensions of the U-shaped gas block The size of the gas silicate block for walls (LxWxH) from 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 of the 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 overall size of the finished block is considered to be a fundamental factor in the change in weight.

Pros and cons of gas silicate blocks

Like any building material, gas silicate blocks have strengths and weaknesses. The positive characteristics include the following points:

1. Aerated concrete belongs to the category of non-combustible materials and is able to withstand exposure to an open flame for up to 5 hours, without changing its shape and properties.
2. Large overall dimensions ensure the rapid erection of wall structures.
3. The blocks have a specific low weight, which greatly simplifies the workflow.
4. Only natural materials are used in the production, so gas silicate blocks are environmentally friendly.
5. The porous structure provides high values ​​of thermal insulation of the premises.
6. The material is easy to process, which helps to build walls with complex geometry.

The disadvantages include the following:

1. They absorb moisture well, which reduces the service life.
2. Application for adhesion of special adhesive compositions.
3. Mandatory exterior finish.

It should be noted that a solid foundation is required for gas silicate blocks. In most cases, a reinforcing belt is required.

Gas silicate blocks are a kind of lightweight cellular material that has a fairly wide scope in construction. Porous concrete products of this type have earned popularity due to their high technical qualities and numerous positive characteristics. What are the advantages and disadvantages of gas silicate blocks, and what are the features of their use in the construction of houses?

Gas silicate is considered an improved analogue of aerated concrete. The production technology of 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 magnesium and calcium oxides;
• fine quartz sand.

From a mixture of such components, a high-quality porous material with good technical characteristics is obtained:

1. Optimum thermal conductivity. This indicator depends on the quality of the material and its density. The brand of gas silicate blocks D700 corresponds to a thermal conductivity of 0.18 W / m ° C. This figure is slightly higher than many other building materials, including reinforced concrete.
2. Frost resistance. Gas silicate blocks with a density of 600 kg / m³ are able to withstand more than 50 freezing and thawing cycles. Some new brands have a declared frost resistance index of up to 100 cycles.
3. The density of the material. This value varies depending on the type of gas silicate - from D400 to D700.
4. The ability to absorb sounds. The soundproofing properties of cellular blocks are equal to a coefficient of 0.2 at an audio frequency of 1000 Hz.

Many technical parameters of 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. It is possible to increase the strength of products by increasing the dose of the cement mixture, but this will reduce the porosity of the material, which will affect its other technical characteristics.

Kinds

Gas silicate blocks are divided depending on the degree of strength into three main types:

1. Structural. Such material is used for the construction of buildings not exceeding three floors. The block density is D700.
2. Structural and thermal insulation. Gas silicate of this type is used for laying load-bearing walls in buildings no higher than two floors, as well as for the construction of interior partitions. Its density ranges from D500 to D700.
3. Thermal insulation. The material is successfully used to reduce the degree of heat transfer of walls. Its strength is low, and due to the high porosity, the density reaches only D400.

Gas silicate building blocks are produced in two ways:

• Autoclaved. The manufacturing technique consists in processing the material under high steam pressure of 9 bar and a temperature regime of 175 degrees. Such steaming of blocks is carried out in special industrial autoclaves.
• Non-autoclave. The prepared mixture of gas silicate hardens naturally for more than two weeks. At the same time, the required air temperature is maintained.

Gas silicate made by autoclaving has the highest technical characteristics. Such blocks have good indicators of strength and shrinkage.

Size and weight

The size of the gas silicate block depends on the type of material and its manufacturer. The most common are such dimensions, which are expressed in millimeters:

• 600x100x300;
• 600x200x300;
• 500x200x300;
• 250x400x600;
• 250x250x600.

Due to its cellular structure, gas silicate is a fairly light material. The weight of porous products differs according to the density of the material and its size:

• D400 - from 10 to 21 kg;
• D500-D600 - from 9 to 30 kg;
• D700 - from 10 to 40 kg.

The small mass of blocks and the possibility of selecting their required size greatly facilitates the construction process.

Scope of application of gas silicate blocks

In construction, gas silicate is successfully used for such purposes:

• construction of buildings;
• thermal insulation of various buildings;
• insulation of thermal engineering structures.

The number of cells per cubic meter in produced gas silicate blocks is different. Therefore, the scope of the material directly depends on the density of the material:

1. 700 kg/m³. Such blocks are most effectively used in the construction of high-rise buildings. The construction of high-rise buildings from gas silicate is much cheaper than from reinforced concrete or brick.
2. 500 kg/m³. The material is used for the construction of low buildings - up to three floors.
3. 400 kg/m³. Such gas silicate is suitable for laying one-story premises. Most often it is spent for inexpensive outbuildings. In addition, the material is successfully used for thermal insulation of walls.
4. 300 kg/m³. Cellular blocks with a low density index are designed to insulate load-bearing structures. The material is not able to withstand high mechanical loads, therefore it is not suitable for the construction of walls.

The lower the density of cellular blocks, the higher their thermal insulation qualities. In this regard, gas silicate structures with a dense structure often require additional insulation. Expanded polystyrene boards are used as insulating material.

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:

1. Blocks intended for the construction of houses have high strength. For a medium density material of 500 kg/m³, the mechanical compression index is 40 kg/cm3.
2. The light weight of gas silicate products allows you to avoid additional costs for the delivery and installation of blocks. The cellular material is five times lighter than conventional concrete.
3. Due to good heat transfer, the consumption of heat energy is reduced. This property allows you to significantly save on heating the building.
4. High level of sound insulation. Due to the presence of pores, the cellular material protects against the penetration of noise into the building ten times better than brick.
5. Good environmental properties. The blocks do not contain toxic substances and are completely safe to use. According to many environmental indicators, gas silicate is equated to a tree.
6. High vapor permeability of products allows you to create good microclimate conditions in the room.
7. The non-combustible material prevents the spread of fire in the event of a fire.
8. The exact proportions of the dimensions of the blocks make it possible to perform even masonry walls.
9. Affordable material price. With good technical performance, the price of gas silicate blocks is relatively low.

Along with a considerable number of advantages, the porous material has some disadvantages:

1. The mechanical strength of the blocks is somewhat lower than that of reinforced concrete and bricks. Therefore, when driving nails into the wall or screwing in dowels, the surface easily crumbles. Blocks hold heavy parts quite poorly.
2. Moisture absorption capacity. Gas silicate absorbs water well and quickly, which, penetrating into the pores, reduces the strength of the material and leads to its destruction. During the construction of buildings from various types of porous concrete, surface protection from moisture is used. It is recommended to apply plaster on the walls in two layers.
3. The frost resistance of the blocks depends on the density of the products. Grades of gas silicate below D 400 are not able to withstand a cycle of 50 years.
4. The material is prone to shrinkage. Therefore, especially in 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 kept 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 efficient construction of low-rise buildings. Some characteristics far exceed the advantages of other materials. With the help of lightweight gas silicate blocks, it is possible to build a reliable building at low cost in a relatively short time.