Gas silicate blocks - basic properties and characteristics. Technical characteristics of gas silicate blocks Aerated concrete blocks strength

In modern building technologies, great importance is attached to the choice of material for the construction of a particular type of building. One of the most popular building materials today is gas silicate blocks, which have a number of advantages and are used quite often.

Their widespread use is due to the optimal balance of price and quality - by and large, no other building material can withstand this proportion as profitably.

If you look at it, it is unlikely that aerated concrete belongs to modern building materials - it was developed back in the late 19th century. At the beginning of the last century, a group of scientists even patented the discovery of a new miracle material, but its properties were far from those that distinguish today's gas silicate.

In its modern form, gas silicate material was obtained at the end of the 20th century - this is concrete with a cellular structure, the hardening of which occurs in an autoclave. This method was found back in the 30s, and since then it has not changed much. Improvement of characteristics occurred due to the introduction of refinements in the technology of its production.

Aerated concrete is one of the bases for the production of gas silicate blocks

Manufacturing principle

The following substances are used as initial ingredients for the production of aerated concrete:

• sand;
• cement;
• lime;
• gypsum;
• water.

To obtain a cellular structure, a portion of aluminum powder is added to the composition, which serves to form bubbles. After mixing, the mass is kept for the required time, waiting for swelling, after which it is cut into pieces and placed in an autoclave. There, the mass hardens in a steam environment - this technology is energy-saving and highly environmentally friendly. In the manufacture of aerated concrete, there is no release of harmful substances that can cause significant harm to the environment or human health.

Properties

The characteristics that distinguish gas silicate blocks make it possible 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 - walls made of it are durable and protect well from the cold.

The porous structure of the blocks guarantees high fire safety performance

The cellular structure explains the small coefficient of thermal conductivity - it is much lower than that of a 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 give the main properties of gas silicate, thanks to which it has become so popular in the construction industry:

• small weight with impressive dimensions- This feature allows you to significantly reduce installation costs. In addition, a crane is not required for loading, transporting and erecting walls - an ordinary winch is enough. The speed of construction for this reason is also much higher than when working with bricks;
• good machinability- the gas silicate block can be sawn, drilled, milled without problems using a conventional tool;
• 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, while, unlike wood, it does not rot and is not subject to aging;
• manufacturability- gas silicate blocks are made in such a way that it is convenient to work with them. In addition to a small mass, they are distinguished by a convenient shape and technological recesses, grips, grooves, etc. Due to this, the speed of working with them increases by 4 times compared with the construction of brick buildings;
• low thermal conductivity of gas silicate blocks- it is due to the fact that aerated concrete is 80 percent air. In buildings that are built from this material, heating costs are reduced, moreover, they can be insulated one third weaker;

A stable microclimate will be maintained in a gas silicate house at any time of the year

• frost resistance- in the structure there are special voids where moisture is displaced during freezing. If all technical requirements for manufacturing are met, the frost resistance of aerated concrete exceeds two hundred cycles;
• soundproofing- a very important parameter, because today the noise level on the streets is quite high, and at home you want to relax in silence. Due to the porous structure, gas silicate retains sound well, differing favorably from brick in this regard;
• fire safety- mineral substances that are used to make gas silicate do not support combustion. Gas silicate blocks are able to withstand the effects of fire for 3-7 hours, so it is used for the construction of chimneys, elevator shafts, fire-resistant walls, etc.;
• high strength- gas silicate withstands 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-hygroscopicity- aerated concrete does not absorb water, which, once on it, dries quickly, leaving no traces behind. This is due to the fact that the porous structure does not retain moisture.

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The main disadvantage of gas silicate is insufficient bending strength, however, the specifics of its use is such that it practically excludes 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.

Brands of gas blocks

The density of gas silicate blocks is the main criterion that is considered when marking. Depending on its size, the building material has different sets of characteristics, which determines the scope of its application.

Below we will look at various grades of gas silicate and how they are used in construction:

• D300- the most suitable building material for the construction of monolithic buildings. The density of gas silicate blocks of this brand is 300 kg / m 3 - it is well suited for building walls of low-rise buildings in one layer or for two-layer monolithic houses with a high degree of thermal insulation;
• D400- it is used for the construction of two-story buildings and cottages, as well as for thermal insulation of the external load-bearing walls of high-rise buildings;
• D500- this is a variety with the best combination of insulation and structural characteristics. In terms of density, it is identical to a log or wooden beam and is used for the construction of partitions and internal walls of buildings, window and door openings, as well as shells of reinforced lintels, rafters and stiffeners;
• D600- this is a gas silicate block with the highest density, which is 600 kg / m 3, it is used where it is necessary to install strong walls subject to high loads.

Below is a table illustrating other parameters that distinguish gas silicate blocks of different brands.

Depending on the density, all gas silicate blocks are usually divided into structural, structural and heat-insulating and heat-insulating

Dimensional accuracy

Gas silicates may have some deviations in their dimensions. Depending on their size, three categories of accuracy of this material are distinguished:

• The first category - it is designed to lay the block dry or on glue. It allows an error in dimensions in height, length and thickness up to one and a half millimeters, rectangularity and angles - up to two millimeters, ribs - up to five millimeters.
• The second category is used to lay gas silicate blocks on glue. In it, the error in the main dimensions is allowed up to two millimeters, rectangularity - up to 3 millimeters, corners - up to 2 millimeters and ribs - up to 5 millimeters.
• The third category of gas blocks is placed on the solution, in which the error in the main dimensions is not more than 3 millimeters, in rectangularity - less than 3 mm, corners - up to 4 millimeters, ribs - up to 10 millimeters.

The choice of gas silicate

When buying gas silicate blocks, three criteria are usually evaluated that affect the decision:

• functional characteristics - density, frost resistance, thermal conductivity coefficient, etc.;
• the size of one block;
• volume of one block;
• price.

The massive use of gas silicate blocks in construction indicates their great popularity. In terms of value for money, with the remarkable characteristics of aerated concrete blocks, nothing more optimal than gas silicate has yet been invented. Aerated concrete is autoclaved cellular concrete - a time-tested building material used in almost all types of structural elements of structures and buildings for various purposes. But where did the technology for the production of cellular concrete come from, and when did it begin to be used in its modern form? Developments aimed at obtaining a new multifunctional building material have been carried out since the end of the 19th century. By the beginning of the 20th, several foreign experimental scientists managed to obtain a patent for the invention of the so-called “miracle concrete”, because at that time the world was in dire need of large quantities of artificially produced stone for construction. Experimenting with the constituent elements, by trial and error, a prototype of a modern aerated concrete solution was obtained. However, the properties and characteristics of gas silicate blocks were not the same as we know them now, of course, at that time. Modern gas blocks appeared only in the 90s. These are well-known foam concrete, polystyrene concrete and aerated concrete blocks. Regarding the latter, they are of 2 types: non-autoclave and, accordingly, autoclave method of hardening. Non-autoclaved aerated concrete is heterogeneous and quite often contains harmful air pores, which shrink during the operation process. Aerated concrete obtained as a result of using the autoclave method is much more environmentally friendly and stronger than non-autoclaved one (about two times). The method for the production of cellular concrete was proposed in the thirties and since then, in principle, has not changed much, although the properties of gas silicate blocks have been constantly improved and the scope of its application has expanded. For its manufacture, sand, cement, lime, gypsum stone and ordinary water are used. A small amount of aluminum powder is also added to the mixture of these materials, which contributes to the formation of small air cells in the mixture, which make the material porous. Immediately after swelling, a short exposure and cutting the array into products of the required dimensions, the cellular concrete mass is placed in an autoclave, where it hardens in a steam environment. This energy-saving technology does not leave any waste that would pollute the air, soil and water. Autoclaved gas silicate blocks are a material with unique properties. After all, it combines the best qualities of two ancient building materials: wood and stone. In recent years, due to a noticeable increase in the requirements for the thermal insulation qualities of enclosing structures in residential and public buildings, one of the few varieties of concrete, from which it is possible to build truly heat-efficient structures of optimal thickness, is precisely cellular concrete. The characteristics and properties of gas silicate blocks give this building material a number of very important advantages:

Light weight gas silicate blocks.

Here, perhaps, the main and indisputable advantage of gas silicate over brick. The weight of the gas silicate block is in the range of 488 - 500 hundred kilograms / m3, depending on the size of the aerated concrete blocks.

A conventional block (according to GOST 21520-89) has a density grade of D500 and a size of 250 by 625 with a thickness of 400 mm and a mass of about 30.5 kilograms and, in terms of thermal conductivity, can replace a 64 cm thick wall of twenty-eight bricks, whose weight is one hundred and twenty kilograms. The large dimensions of gas silicate blocks with low weight significantly reduce installation costs and significantly reduce construction time. To carry out the lifting of aerated concrete, a crane is not needed: several people can handle this, or you can use an ordinary winch, therefore, the light weight of such cellular concrete allows you to reduce not only transport and installation work, but also the cost of arranging foundations. Aerated concrete blocks are much easier to process than foam concrete. They can be sawn, drilled, planed and milled with conventional tools.

Blocks gas silicate environmental friendliness.

Since autoclaved aerated concrete is obtained from sand, cement, lime and aluminum powder, it is not toxic substances are released, as a result, in its environmental friendliness, it is close to wood, but it is not prone to decay and aging. Aerated concrete products are completely safe for humans; in a house built from it, one breathes just as easily as in a house built from wood.

Fast and economical when working with gas silicate blocks.

Thanks to such a characteristic of gas silicate blocks as their impressive dimensions (600 by (50-500) by 250 mm), with low weight, the construction process proceeds quickly and easily. At the same time, the speed of construction increases really significantly (4 times) and, accordingly, labor costs decrease. At the ends of some types of gas silicate block, special grooves and ridges are formed, as well as gripping pockets designed for hands. You absolutely do not need 1-1.5 cm of mortar in the masonry, an adhesive layer of 3-5 millimeters applied with a notched trowel is enough to securely strengthen the block. Aerated concrete blocks have an almost ideal configuration (since the permissible deviation of their faces does not exceed one millimeter), which makes it possible to use the technology of thin-seam masonry and significantly reduces the cost of work. The cost of gas silicate blocks is low compared to the same brick, but the glue for making thin seams is about twice as expensive as the price of sand-cement mortar, but the material consumption in the production of aerated concrete block masonry is reduced by about six times. Ultimately, the resulting thin-joint masonry makes it possible to reduce the cost of masonry mortar by a factor of three, in addition, due to the minimum thickness of the connecting adhesive, cold bridges in the walls are reduced and the house is warmer.

Gas silicate blocks low thermal conductivity.

It is provided by air bubbles, which occupy about 80 percent of the material. Indeed, it is thanks to them that among the positive qualities of aerated concrete blocks there is a high thermal insulation capacity, due to which heating costs are reduced by 20-30 percent and you can refuse to use additional heat-insulating materials. The walls, which are made of gas silicate blocks, fully meet the new SNiP requirements for the thermal conductivity of the walls of public and residential buildings. In a dry state, the thermal conductivity coefficient of aerated concrete is 0.12 W / m ° C, at 12% humidity - 0.145 W / m ° C. In central Russia, it is possible to build walls from gas silicate blocks (with a density of not more than 500 kilograms / m3), whose thickness is 40 cm.

Energy saving thanks to gas silicate blocks.

Today, energy saving has become one of the most important indicators. It happens that the neglect of this parameter leads to the impossibility of operating a solid brick house: the owner simply could not afford to financially heat such a large room. When using an aerated concrete block with a weight of 500 kilograms / m3, a thickness of 40 cm, the energy-saving parameters are achieved within the normal range. The use of aerated concrete blocks with a density of more than 500 kg / m3 leads to a noticeable deterioration in the parameters (thermal properties are reduced by fifty percent when using blocks with a density of 600-700 kg / m3). Gas silicate blocks with a density of less than 400 kilograms / m3 can only be used in construction as a heater, due to their low strength characteristics.

Blocks gas silicate frost resistance.

The qualities of aerated concrete blocks in terms of frost resistance allow them to become champions among the materials used in low-rise construction. Excellent frost resistance is explained by the presence of reserve voids into which water is displaced during freezing, while the gas silicate block itself is not destroyed. If the technology of building from aerated concrete is strictly observed, the frost resistance of building materials exceeds two hundred cycles.

Soundproofing qualities of aerated concrete blocks.

Due to its cellular finely porous structure, the soundproofing qualities of gas silicate are many times higher than that of brickwork. If there is an air gap between the layers of aerated concrete blocks, or when finishing the wall surface with denser building materials, sound insulation of about 50 dB is provided.

Blocks of autoclave hardening fire safety.

Cellular aerated concrete blocks are not afraid of fire. Chimneys made of gas silicate blocks are laid through any wooden structures without cutting, since they conduct heat poorly. And since only mineral raw materials of natural origin are used to produce aerated concrete, aerated concrete blocks belong to the group of materials that do not support combustion and are able to withstand one-sided fire exposure for 3-7 hours. When using aerated concrete blocks in conjunction with metal structures, or as cladding, they are ideal for the construction of fire-resistant walls, elevator and ventilation shafts.

Blocks aerated concrete strength.

With a low volumetric weight of the gas silicate block - 500 kilograms / m3 - it has a rather high compressive strength - in the region of 28–40 kgf / cm3 due to autoclave treatment (for comparison, the same foam concrete is only 15 kgf / cm3). In practice, the strength of the block is such that it can be safely used in the construction of houses with load-bearing walls up to 3 floors, or without limiting the number of storeys - in frame-monolithic construction.

Gas silicate blocks ease and rationality of processing.

Blocks of aerated concrete are quite easy to any mechanical processing: they can be sawn, drilled, planed, milled without problems, using standard tools that are used for wood processing. Channels for pipes and cables can be laid using conventional hand tools, or you can use power tools to speed up the process. A hand saw will make it easy to give the gas silicate any configuration, which completely solves the issues with additional blocks, as well as the external architectural expressiveness of structures. Channels and openings for arranging electrical wiring, sockets, pipelines, etc. can be cut using an electric drill.

Blocks are gas silicate sizes.

The autoclave block manufacturing process guarantees highly accurate dimensions - typically 250 x 625 millimeters with varying thicknesses of 50 - 500 millimeters (+- millimeter). Deviations, as you can see, are so minimal that a freshly laid wall is a surface that is absolutely ready for applying putty, which is the basis for wallpaper or painting.

Non-hygroscopicity of aerated concrete block.

Although the autoclaved aerated concrete block is a highly porous material (its porosity can reach up to 90 percent), the material is not hygroscopic. Having fallen, for example, under the rain, aerated concrete, unlike the same wood, dries out rather quickly and does not warp at all. Compared to brick, aerated concrete does not “suck up” water at all, since its capillaries are interrupted by special spherical pores.

Aerated concrete blocks application.

The lightest in weight gas silicate blocks, having a density of 350 kilograms / m³, are used as a heater. Aerated concrete blocks with a density of four hundred kg / m³ are used for the construction of load-bearing walls and partitions in low-rise housing construction. Having high strength properties, gas silicate blocks - 500 kilograms / m³ - are applicable for the construction of both non-residential and residential facilities, reaching more than 3 floors in height. And, finally, those gas silicate blocks, whose density is 700 kg / m³, are ideal for the construction of multi-storey buildings when reinforcing row spacings, and are also used to create light floors. Builders call gas silicate blocks that do not require special care unpretentious and eternal. The autoclave block is great for those looking to reduce construction costs. The cost of aerated concrete blocks is low, in addition, the construction of a gas silicate house requires less finishing and building materials than brick. Yes, and working with gas silicate blocks is quite simple, which reduces labor costs and speeds up the process of building buildings - the construction of gas silicate blocks is carried out on average four times faster than when working with bricks.

Blocks gas silicate delivery and storage.

Blocks of gas silicate are packed by the manufacturer in a fairly durable heat-shrinkable sealed film, which reliably protects the material from moisture. Therefore, there is no need to take care of the proper protection of aerated concrete from negative atmospheric influences. The main task of the buyer, who independently transports aerated concrete blocks, is to protect them from various kinds of mechanical damage. When transported in the body, pallets with installed blocks must be rigidly fixed with soft straps, which are designed to prevent pallets with blocks from moving and friction. When unloading building materials, soft slings are also used. If aerated concrete blocks are released from the protective film and are stored in an open area, subject to precipitation - please note that the characteristics of aerated concrete blocks deteriorate from high humidity, therefore this material should be kept under a canopy or even in a closed warehouse.

Aerated concrete block masonry.

Work on the construction of buildings from aerated concrete blocks can be carried out at temperatures up to - 50 degrees; when using special frost-resistant glue. Since aerated concrete is a fairly light material, it does not cause glue to be squeezed out. Unlike brick walls, those made of aerated concrete can be laid out without pauses. According to building codes, gas silicate blocks with a thickness of 375 - 400 millimeters are used for laying out external walls, and at least 250 for interior walls. it should be slightly larger than the width of the aerated concrete blocks in the masonry. The first layer of gas silicate blocks for the purpose of leveling is placed on the mortar in order to compensate for the existing unevenness of the foundation. The laying of the gas silicate block is started from the highest building corner in terms of size. Blocks with the help of a level and a rubber hammer are leveled, polished - with a grater, after which the masonry is thoroughly cleaned of dust. Laying the very first row of gas silicate blocks should be given special attention, because the convenience of all further work and the final quality of construction depend on its evenness. You can control the laying of gas silicate blocks using a level and a cord. The next row of laying gas silicate blocks starts from any of the corners. In order to ensure maximum evenness of the rows, do not forget to use a level, and if the wall is long, also beacon intermediate blocks. Laying of rows is carried out with mandatory dressing of gas silicate blocks - that is, the displacement of each subsequent row relative to the previous ones. The minimum offset value becomes 10 centimeters. The glue that protrudes from the seams is not overwritten, but removed with a trowel. Blocks of gas silicate with a complex configuration and additional ones are made with a hacksaw for blocks.

Internal partitions from gas silicate blocks.

Regardless of which of the modern partition designs you decide to use in your own home (for example, partitions made of metal profiles and drywall sheets), you will still need to make some kind of sandwich system using insulation in order to achieve the optimal level of sound insulation. And, as you know, any of the sandwich systems in terms of labor intensity is much higher and more expensive than masonry from gas silicate blocks. The problem with partitions is easily solved by aerated concrete block. For the construction of internal partitions, aerated concrete blocks are taken, having a thickness of 75 and 100 millimeters and a density of 500. As a result, the wall is quite strong, heat and sound insulated, but at the same time light.

Reinforcement when laying from gas silicate blocks.

When arranging walls in low-rise residential buildings from aerated concrete blocks, reinforcement is used, which is assigned according to a special calculation, in accordance with a specific project. As a rule, reinforcement is made through two to four rows of masonry; additionally, reinforcement is installed in the corners of buildings.

Aerated concrete blocks, therefore, is a truly economical and efficient building material, whose properties make it possible to construct buildings for various purposes in the shortest possible time. Gas silicate blocks are produced in two types: wall and partition. Both those and others are certified according to GOST. This highly environmentally friendly material is manufactured using advanced technologies using the most modern equipment, which ensures the highest quality and constancy of important technical characteristics for the gas silicate block. If you are interested in buying it, please contact the company Attribute-C , because we know everything about aerated concrete and offer our customers only high-quality gas silicate blocks, manufactured according to all technological standards and having impeccable characteristics of strength, thermal insulation, durability, etc. Attribute-C will provide you with any volume of aerated concrete blocks and, importantly, in addition to selling, we also offer you fast delivery of aerated concrete blocks with careful unloading. You will appreciate our impeccable service and prices for gas silicate blocks, which are noticeably lower than many similar organizations in the Moscow region. It is easy to order gas silicate blocks with delivery, you just need to contact us by phone 8-499-340-35-47, or send a request to the address This e-mail address is being protected from spambots. To view it you must have Javascript enabled. You can be sure that they will definitely answer you and discuss all the terms of payment and delivery of gas silicate blocks. And if you have any questions - write and get all the answers you are interested in.

Additional information about aerated concrete blocks:

Blocks of gas silicate are in great demand in residential and industrial construction. This building material surpasses concrete, brick, natural wood, etc. in many respects. It is made from environmentally friendly raw materials, is lightweight, fireproof, easy to operate and transport. The use of this lightweight material reduces the cost of arranging a heavy reinforced foundation and thereby reduces the cost of building a building.

What are gas silicate blocks

The gas silicate block is a lightweight and durable wall material, which is made of cellular concrete. Products have a porous internal structure, which has a positive effect on their heat and noise insulation properties. Such building material 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 are gas silicate blocks made?

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

• non-autoclave. With this method of production, the solidification of the working mixture occurs in natural conditions. Non-autoclaved gas silicate blocks are distinguished by a lower cost, but have some important differences from autoclaved ones. First, they are less durable. Secondly, when they dry, shrinkage occurs almost 5 times more intensively than in the case of autoclaved products.
• Autoclave. For the autoclave production of gas silicate, more energy and material resources are required, which increases the final cost of products. Production is carried out at a certain pressure (0.8-1.2 MPa) and temperature (up to 200 degrees Celsius). Finished products are more durable and resistant to shrinkage.

Block types

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

• Structural. They have high strength properties. The density of products is not less than 700 kg/m 3 . They are used in the construction of high-rise structures (up to three floors). Able to withstand high mechanical loads. The thermal conductivity is 0.18-0.2 W/(m·°C).
• Structural and heat-insulating. Blocks with a density of 500-700 kg / m 3 are used in the arrangement of load-bearing walls in low-rise buildings. They are distinguished by a balanced ratio of strength and heat-insulating characteristics [(0.12-0.18 W / (m ° C)].
• Thermal insulation. They are distinguished by increased heat-insulating 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

Gas silicate wall blocks have standard dimensions of 600 x 200 x 300 mm. The overall characteristics of the semi-blocks are 600 x 100 x 300 mm. Depending on the manufacturer, the 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, semi-blocks - 10-16 kg;
• structural and heat-insulating blocks and semi-blocks - 17-30 kg and 9-13 kg, respectively;
• heat-insulating blocks weigh 14-21 kg, semi-blocks - 5-10 kg.

Composition of gas silicate blocks

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

Material characteristics

Building blocks made of gas silicate have the following characteristics.

• Heat capacity. Products made using autoclave technology have a thermal conductivity coefficient of 1 kJ/(kg °C).
• Thermal conductivity. Structural and heat-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 withstands up to 35 freeze and thaw 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. Blocks of gas silicate 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 microclimate inside the premises.
• Environmental friendliness. The composition of the building material does not contain dangerous toxins and carcinogens that can harm the environment and human health.
• fire resistance. Gas silicate is made from non-combustible raw materials, therefore it does not collapse during intense heating and does not contribute to the spread of flame in case of fire.

How critical are the shortcomings?

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

• Low margin of safety. Material with low density (300-400 kg/m3) has relatively low strength characteristics. Therefore, during construction, it is imperative to carry out work on the reinforcement of 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 worsens, 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 need 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 engineering networks (in particular, heating).

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

• Products whose density is 300-400 kg / m 3 have a low margin of safety, so they are used mainly for wall insulation.
• Gas silicate with a density of 400 kg / m 3 is suitable for the construction of one-story houses, garages, office and outbuildings. Due to the 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 for the construction of 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 facilities. 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.

In the construction industry, gas silicate products are used. The block production process is carried out under high pressure, as well as in natural conditions. Due to the porous structure, they retain heat well. The D500 gas silicate block is popular, the characteristics of which make it possible to use this material in the construction of houses. As a result of the use of blocks of increased size, the building construction cycle is reduced. Consider the main technical characteristics that must be considered when choosing a material.

What are gas silicate blocks

Gas silicate block products are a modern building material made from the following raw materials:

• Portland cement, which is a binder ingredient;
• quartz sand introduced into the composition as a filler;
• lime involved in the gas formation reaction;
• powdered aluminum added to foam the mass.

When mixing the components, the working mixture increases in volume as a result of an actively occurring chemical reaction.

Gas silicate blocks are widely used in the construction industry

Molding containers filled with silicate mixture solidify under various conditions:

• naturally at ambient temperature. The curing process lasts 15-30 days. The resulting products are characterized by a reduced cost, but have insufficiently high strength;
• in autoclaves, where products are heated at elevated pressure. Steaming allows you to increase the strength characteristics and specific gravity of gas silicate products.

The density and strength indicators change depending on the manufacturing method. The indicated characteristics of the materials determine the area of ​​use.

Blocks are divided into the following types:

• structural products. They are marked D700 and are in demand for the construction of main walls, the height of which is no more than three floors;
• thermal insulation products. Brand D500 corresponds to these blocks. They are used for the construction of internal partitions and the construction of load-bearing walls of small buildings;
• thermal insulation products. They are characterized by increased porosity and density reduced to D400. This allows the use of gas silicate material for reliable thermal insulation of walls.

The digital index in the marking of the blocks corresponds to the mass of one cubic meter of gas silicate, indicated in kilograms. As the density of the material increases, its thermal insulation properties decrease. Products of the D700 brand are gradually replacing traditional bricks, and products with a density of D400 are not inferior in terms of thermal insulation properties to modern heaters.

Gas silicate blocks are superior in mechanical strength to foam concrete

Gas silicate blocks - the pros and cons of the material

Gas silicate products have a complex of serious advantages. The main advantages of gas silicate blocks:

• reduced weight with increased volume. The density of gas silicate material is 3 times less compared to brick and about 5 times lower when compared to concrete;
• increased margin of safety, allowing to perceive compressive loads. The strength index for a gas silicate block marked D500 is 0.04 t / cm³;
• improved 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 block shape. Due to the reduced tolerances for overall dimensions and clear geometry, the laying of blocks is carried out on a thin layer of adhesive mortar;
• increased dimensions. The use of large-sized silicate blocks with low weight for the construction of walls of buildings reduces the duration of construction;
• good machinability. If necessary, it is easy to give the gas silicate block a predetermined shape or cut the block material into separate blanks;
• acceptable price. Using block gas silicate for the construction of a cottage, a private house or a summer residence, it is easy to significantly reduce the estimated cost of construction activities;
• fire safety. Blocks do not ignite when heated and exposed to open flame. They belong to low-combustible building materials included in the combustibility group G1;
• high soundproof properties. They are provided due to the porous structure. In terms of ability to absorb external noise, the blocks are ten times superior to ceramic bricks;
• environmental friendliness. In the manufacture of a gas silicate mixture, toxic ingredients are not used and no components harmful to health are released during operation;
• vapor permeability. Air exchange occurs through the air cells inside the gas silicate massif, creating a favorable microclimate inside the building;
• frost resistance. Gas silicate blocks retain the structure of the array and performance 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 is able to accumulate thermal energy and gradually release it to increase the room temperature.

The area of ​​application depends on the density of the material

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;
• insufficient mechanical strength. Block material crumbles under load, therefore, it requires careful handling during transportation and laying;
• mold formation and the development of fungal colonies inside and on the surface of the blocks. Due to the increased moisture absorption, favorable conditions are created for the growth of microorganisms;
• increased shrinkage. Under real operating conditions, under the influence of loads, the blocks gradually shrink, which causes the formation of cracks after a while;
• reduced adhesion with sand-cement plasters. It is necessary to use special finishing compounds for plastering gas silicate.

Despite the existing shortcomings, gas silicate blocks are actively used for the construction of capital walls in the field of low-rise construction, as well as for the construction of heat-insulated walls of 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.

Gas silicate block D500 - building material characteristics

Structural and heat-insulating block D500 is used for various purposes:

• construction of boxes of low-rise buildings;
• arrangement of interior partitions;
• reinforcement of 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 a popular building material. Let's dwell on the main characteristics.

Strength properties

The compressive strength class of the material varies depending on the block manufacturing method:

• gas silicate grade D500, obtained by the autoclave method, is characterized by a strength index of B2.5-B3;
• the compressive strength class for similar non-autoclaved blocks 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. A relatively low margin of safety allows the use of block building material in the field of low-rise construction. During the construction of multi-storey buildings, gas silicate blocks are used in conjunction with bricks for thermal insulation of the walls being erected.

Specific gravity

The density of gas silicate blocks is an important performance indicator that characterizes the porosity of a block massif. Density is indicated by marking 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. So, one cubic meter of gas silicate marked D500 weighs 500 kg. Knowing the marking of products by density, the dimensions of the blocks and their number, it is easy to calculate the load on the foundation.

Gas silicate blocks - environmentally friendly material

Thermal performance

The thermal conductivity of gas silicate blocks is the ability to transfer thermal energy. The value of the indicator characterizes the thermal conductivity of gas silicate blocks.

The value of the coefficient varies depending on the moisture concentration in the material:

• 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 the 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 perceive temperature changes associated with deep freezing and thawing is characterized by marking. The frost resistance index for D500 products is F50. Compared to other types of composite concrete, this is a fairly good indicator. Frost resistance is affected by the moisture concentration in the blocks. With a decrease in the moisture content of the material, the frost resistance of the blocks increases.

Lifetime

Gas silicate has a long period of use. The structure of the gas silicate massif has been intact for more than half a century. Block manufacturers guarantee the service life of products for 60-80 years, provided that the blocks are protected from moisture absorption. Plastering the material allows you to extend the service life.

Fire safety

Gas silicate blocks are a fireproof building material with fire resistance up to 400 ⁰С. Tests confirm that a gas silicate wall covered with plaster is able to withstand exposure to open fire for three to four hours. The blocks are suitable for the construction of fire-resistant walls, partitions and chimneys.

Conclusion

Block gas silicate is a proven material for the construction of low-rise buildings. The characteristics of the blocks make it possible to ensure the stability of the buildings under construction and maintain a comfortable microclimate inside the buildings.