The difference between foam block and aerated concrete block. Aerated concrete or foam concrete - comparative analysis

Cellular concrete, which includes foam concrete and aerated concrete, is quite popular today. These are materials with good bearing capacity and excellent thermal insulation properties. But for many consumers who are ignorant in the field of building materials, the question often arises: foam concrete and aerated concrete - what is the difference between them. To answer it, you need to understand the production process of the two compounds and compare their technical characteristics.

Consider the terminology

Let's start with the fact that cellular concretes, they are also porous, are cement-based mortars belonging to the category of lightweight concretes. A feature of their structure is pores filled with air or gas. Therefore, these materials have a large number of positive properties.

Now the difference between a foam block and a gas block in terms of terminology. From the name of the two materials it already becomes clear that the first is made on the basis of foam, the second on the basis of gas. How does it all happen.

Production features

The production of cellular concrete is based on two technologies: autoclave and non-autoclave. For the first, special equipment is used, which is called an autoclave. In fact, this is a container into which the concrete mortar poured into the molds is lowered. There it is subjected to high pressure and steam treatment at high temperature.

The second technology is the usual mixing of the components of the solution, poured into molds at normal temperature and without any pressure. In these forms, concrete crystallizes into stone.

For obvious reasons, the autoclave method of production cellular concrete, where pressure is present, has a positive effect on the characteristics of the produced material. He has a higher density, and hence the strength.

So, autoclaved aerated concrete is produced, non-autoclaved foam concrete. This is the first answer to the question of how a foam block differs from a gas block.

Composition of concrete

At the heart of the recipe for the manufacture of foam concrete is the cement composition. A special additive is introduced into it as a component for the formation of pores. Manufacturers today offer different types of these additives: on a synthetic basis or organic. The main task of production is to accurately maintain the proportions of cement mortar and additives. On the packaging of the latter, the manufacturer necessarily indicates the quantitative ratio.

So, the foaming additive is added to the cement composition, all this is well mixed and poured into molds. Here the concrete hardens into natural environment. Since the foam was inside the solution, its air bubbles form pores (cells).

Foam concrete can be poured at the place of requirement, constructing formwork for it. That is, it is possible to build monolithic structures from it. According to experts in this regard, foam concrete is superior to its competitor.

Now about the recipe for aerated concrete. There is state standards, in which the classic recipe is precisely defined. The composition of aerated concrete includes:

• Portland cement brand M500 DO or M 400 DO.
• Quartz sand with a particle size modulus of not more than 1.5 mm. At the same time, it must be washed and dried. Clay must not be allowed to enter the aerated concrete.
• Aluminum powder or paste as blowing agent. Most often, powder grades PAP1 or PAP2 are used. The mass fraction of the additive in the solution is not more than 1%.
• Caustic soda, aka caustic soda. As part of the solution, it acts as a gas release accelerator. Its share in the solution is not more than 0.45%.
• Water. It should be clean and warm (+40-60C). It is added at the rate of 1.25 m³ of a solution of 0.5 m³ of water.

Of all the components, the most expensive is aluminum powder. To reduce the cost of aerated concrete, a different recipe is used, in which sand is replaced with crushed limestone (up to 26%) and lime (up to 2.5%). At the same time, the mass fraction of powder is reduced to 0.1%.

It turns out that even in composition there is a difference between the foam block and the gas block. But that's not all. The production of the former can be established at the construction site, the latter are made only in the factory. The first are the exact form of the product, which in finished form is immediately used in the construction of buildings. The second are finished products of great length, which are cut into blocks by special string machines. Blocks are obtained with very flat planes. Hence the answer to the question of what is cheaper: foam block or gas block. The first ones are cheaper: 1 m³ of foam blocks costs within 1500 rubles, gas blocks - 2200 rubles.

Material characteristics

We turn to the technical characteristics and determine which is better: foam concrete blocks or aerated concrete blocks. Immediately make a reservation that both materials are manufactured according to the same GOSTs. It would seem that the characteristics of the foam block and the gas block should be close to each other. But it's not.

Moisture and frost resistance

It is necessary to indicate the fact that all cellular concretes absorb moisture well, which means that they have a low frost resistance index. Therefore, the houses built from them must be outside covered with protective solutions or structures. So in practice, both characteristics are not taken into account. Just for information, we denote that the moisture absorption of aerated concrete is higher than that of foam concrete.

Strength

This is a characteristic that is compared more often than others when the question is raised of what to build a house from. As already mentioned, gas blocks are made under pressure, which makes their density greater. But in this regard, foam blocks on the market are represented by different brands, where the density can compete with gas blocks. At the same time, for the former, the dispersion of density indicators is huge from 100 to 1200 kg / m³. For gas blocks, the spread is small: 600-800 kg / m³.

But at the same time, the spread of compressive strength for both materials is huge: for foam concrete - 2-7.5 MPa, for aerated concrete - 2.5-15 MPa. For the latter material, everything depends on the chosen recipe and the brand of cement used. But if we compare both finished products with the same density, then aerated concrete is stronger, it is also more reliable.

Shrinkage

Another criterion that indicates the differences between foam concrete and aerated concrete. For the first, this indicator is 1-3 mm / m, for the second, 0.5 mm / m. Hence the conclusion: houses made of foam blocks undergo cracking during shrinkage.

Thermal conductivity

It is necessary to compare the thermal conductivity of foam concrete and aerated concrete, taking into account their density. The higher this parameter, the higher the heat-conducting qualities of the material. And since they have the same structure - cellular, then with the same density, the thermal conductivity will be the same. For information:

fire resistance

It is not worth comparing the advantages and disadvantages of two concretes in terms of fire resistance. They belong to the category of non-combustible materials - NG, and that says it all.

Environmental Safety

Here it is necessary to indicate that the chemical reaction that occurs during the manufacture of aerated concrete releases hydrogen. And this scares a lot of people. First, this gas is not poisonous. Secondly, there is a minimum amount of it in the pores. Thirdly, the surfaces from the inside are covered with finishing materials, which act as barrier layers from penetration of any contaminants.

Now about foam concrete. All additives added to it: protein or synthetic are also not harmful to people. Therefore, the question of what to choose from the two materials is not worth it here.

Dimensions

Dealing with the dimensions of foam concrete and aerated concrete, it should be noted that there is a standard the lineup, where foam blocks are mainly represented by three positions:

• a single block with dimensions of 100x300x600 mm, it is used for the construction of partitions;
• one and a half - 150x300x600 mm;
• double - 200x300x600 mm.

Gas blocks have a wider size range, this mainly concerns the width, which varies in the range of 100-400 mm. The height of the blocks is standard - 250 mm, length is either 600 or 625 mm.

Product price

This is one of the most important criteria choice when the question is, how does aerated concrete differ from foam concrete. Due to the fact that an expensive component in the form of aluminum powder is used for the production of the former, and special equipment is used in the technological process, and several types of energy carriers (here we mean electricity and steam), there is no doubt that aerated concrete is more expensive. And the difference is at least 20%.

But that's not all. Aerated concrete blocks during installation are laid on an expensive adhesive composition. But the foam blocks are laid on a conventional masonry mortar of cement and sand. By the way, for the construction of a garage, a barn, a boiler room and other outbuildings, you should not purchase expensive material. This also applies to the frequently asked question, what is better to build a bath from. It is not necessary to increase the construction budget of these buildings.

Vapor permeability

This characteristic also depends on the density of the materials. Therefore, with the same indicator, it will be the same. Although many believe, and this can be seen from the reviews on many portals, foam concrete "breathes" better. It probably depends on the size of the pores.

How to distinguish aerated concrete from foam concrete in appearance is a question that needs clarification. Everything is simple here: the first is a white block, the second is gray. But they also have a different structure. The first cell is smaller than the second. At the same time, the foam block has a structure with closed cells, therefore the outer planes are even. In gas blocks, the cells in the outer layers are open, in the inner layers they are closed, hence the planes into shallow depressions. Therefore, anyone can determine the difference.

Aerated concrete houses

Today construction companies offer a huge number of projects of houses made of aerated concrete and foam concrete. All the pros and cons of materials are taken into account in them. But, as practice shows, the construction of such houses is increasingly being carried out according to the "do it yourself" principle. Neither material nor the other causes difficulties. Of course, it is easier to shift the burden of responsibility onto the shoulders of professionals. And this correct solution, especially if a multi-storey building is being built.

But if the task is to build a small building, then you should not call specialists. All this can be done independently, given everything that was said above. Of course, the question is: what is better for building a house: foam blocks or aerated concrete, even here it will be sharp. Therefore, look at your capabilities, especially financial ones.

And one more topic is the insulation of a house made of aerated concrete or foam concrete. Is it necessary to carry out, given that both materials have good thermal conductivity. It all depends on the region where the house is being built. In the south, this is not necessary; in the north, it is better to carry out thermal insulation measures. At the same time, it is optimal to make external insulation, which will immediately solve the problem of protecting cellular concrete from moisture.

Conclusion

So, all the nuances on the topic, how to distinguish or determine the differences between aerated concrete and foam concrete, and which is better, have been sorted out. Everyone chooses for himself. There is no point in giving advice here. You just need to understand that the choice sometimes depends on the construction budget, so many give their preference to cheaper products. And at the end, another answer to one question: cellular concrete and aerated concrete are the same or not. This is the same thing, just aerated concrete is a subspecies of cellular.

You may also be interested

Recently, cellular concrete has been increasingly chosen as a material for building a house - an artificial building material with a porous structure, one of the varieties of lightweight concrete. Both cottages and apartment buildings are built from this material. At the same time, such buildings are distinguished by the best thermal insulation characteristics in comparison with brick and much stronger than those in the construction of which cinder block was used.

Due to its shape and low dimensional variation, aerated concrete blocks can be laid not on cement mortar, which is a kind of cold bridge in the finished wall, and on a special glue that can significantly reduce the heat transfer of the walls.

There are three ways to porous such concrete: foaming, gas generation and aeration, due to which aerated cellular concrete and silicates are obtained.

A similar material began to be used for the construction of buildings as early as the 19th century, when builders began to add bovine blood to the cement-lime mortar, the protein of which formed foam when reacting with the solution. Neither then, nor in the 30s of the last century, cellular concrete was not widely used and began to gain popularity relatively recently, as a lighter and more inexpensive building material compared to brick. It is characterized by sufficient strength, retains heat better and easily removes excess moisture from the room to the outside.

Today, from high-density foam concrete blocks, it is quite possible to build houses up to three floors. If the design of the house involves the construction of a reinforced concrete supporting frame, then buildings of any number of storeys can be erected from foam blocks.

There are several varieties of foam concrete blocks, different in density, thermal conductivity and frost resistance.

To obtain aerated concrete, special substances are introduced into the cement mortar, which release gas and provide a more even porous structure than in the production of foam concrete.

Features of the production of foam blocks and gas blocks

Foam concrete is obtained by simply mixing pre-prepared foam with a concrete mixture. Such production is much simpler and cheaper than the production of aerated concrete and can be organized, in fact, at any construction site, while reducing transportation costs to zero. The relative ease of production of the foam block is very similar to the cinder block, which can be made from cement, water and screenings in any yard. However, it should be borne in mind that in this case the quality of such foam blocks can be called into question.

There are three ways to get foam concrete blocks.

First- the mixture for blocks is poured into cassette metal molds, where it hardens for about 10 hours. After that, the form is disassembled and ready-made foam blocks are taken out of it. At the same time, perhaps the only thing that distinguishes the cinder block is that pre-prepared foam is not added to the mixture for its production.

Scheme of a cassette mold for the manufacture of foam concrete

Second way involves pouring a large array of foam concrete with a volume of 2–3 cubic meters. Such an array solidifies for about 14 hours, after which the entire array is cut into pieces on a special cutting machine. This method is better because you can get a foam concrete block of any size. In terms of cost, this method is more expensive than the first. In addition, with this method of producing foam blocks, about 0.5% of the concrete goes to waste when sawing.

With the third method production, foam concrete is fed into special forms, which, after solidification of the mass, are taken to automatic demoulding. Finished blocks are extruded from the molds onto a special pallet, and the block molds are automatically lubricated. The main disadvantage of this method is that such an installation cannot be reconfigured; it can produce foam blocks of only one shape and size.

Any Internet forum that discusses construction issues is ready to offer a ready-made video of the production process of foam concrete blocks, as well as cinder blocks.

In the production of aerated concrete, not pre-prepared foam is added to the concrete mixture, but a foaming agent - an aqueous suspension of aluminum powder, which reacts with the fillers of the mixture. As a result, hydrogen bubbles up to 2 millimeters in diameter are formed in the concrete, which are evenly distributed throughout the material. After pre-hardening of the mixture, the mass is cut into blocks of equal size, which are subjected to heat treatment in an autoclave.

Aerated concrete production

Professional skills are required to use such equipment. But the finished blocks are highly frost-resistant and resistant to cracking, they can be easily used in the construction of houses and other buildings.

In the non-autoclaved aerated concrete production method, the cut blocks are left to harden under natural conditions. This method of production is more economical due to the reduction of energy consumption, but it also has a significant drawback.

So, with the same density of the material, non-autoclaved concrete shrinks by 2-3 millimeters, while during heat treatment, shrinkage does not exceed 0.3 mm.

In addition, with this method of production, the technology also implies an increased consumption of cement.

Due to this, it was the autoclave that became more widespread. aerated concrete block.

Pros and cons of foam concrete and aerated concrete blocks

The advantages of foam concrete and aerated concrete over traditional, familiar building materials are similar. Aerated concrete and foam concrete blocks weigh less than a brick and are more durable than a cinder block, the very name of which, as some builders joke, speaks eloquently of the quality of this material. They are easier to transport and, due to their low weight, save money already at the very beginning of construction by laying a lightweight foundation at the base of the building. At the same time, the main differences of foam concrete, along with its lower cost, are its disadvantages.

Aerated concrete is easy to process

Blocks of cellular concrete of both types are easily mounted together. Therefore, the construction of walls of houses from such blocks takes a third less time than for walls made of ordinary bricks, but aerated concrete is also much better amenable to additional processing. What other stone, albeit artificial, can be cut with an ordinary hacksaw if necessary? Even cinder blocks are less pliable for cutting.

Hygroscopicity and frost resistance

Both materials have low moisture resistance, so the walls of houses made of them need additional processing with different compositions. The aerated concrete block absorbs moisture better due to the fact that the pores in it are not only closed, as in foam concrete, but also open. He takes him out of the room excess moisture and "breathes" due to its porosity is also much better. In the same conditions high humidity the facade of the aerated concrete building will need to be additionally protected from direct moisture.

Due to its porous structure, there is always a reserve place inside the blocks for water to move when it freezes. Therefore, the frost resistance of foam concrete ranges from F15 to F50.

Autoclaved aerated concrete, in turn, is able to withstand about 200 freezing cycles, which corresponds to approximately 500 years of wall operation. At the same time, GOST requires only 35 freezing cycles for this material.

Strength

Foam concrete and aerated concrete blocks can be produced with different material densities: from 300 to 1200 kg/m3.

However, with equal density, the foam concrete block noticeably loses to autoclaved aerated concrete in strength, which largely depends on the quality of the foam concentrates.

Since foam concrete can be made almost artisanally, many manufacturers use their cheaper counterparts instead of high-quality components of mixtures. At the same time, the cost of foam concrete blocks decreases, but their quality as a building material does not get better.

Shrinkage

Masonry of autoclaved aerated concrete blocks is less prone to cracking than a wall of foam concrete. Shrinkage of autoclaved aerated concrete usually does not exceed 0.5 mm per 1 meter of masonry. At the same time, for foam concrete blocks, shrinkage can reach 3 mm/m.

thermal insulation

The thermal conductivity of foam blocks is three times lower than that of conventional bricks. They are distinguished from aerated concrete blocks by the fact that the pores inside the block are unevenly distributed and can vary greatly in size. Somewhere the time turned out to be more, somewhere - less, and in some place it did not form at all. Because of this, it is difficult to say that even one block of foam concrete is able to provide the same level of thermal conductivity throughout its volume.

The texture of gas blocks has more pores and they penetrate the entire material evenly. Therefore, their thermal insulation qualities are better than those of foam blocks.

Only a cinder block can have a lower thermal conductivity than aerated concrete blocks. However, in his case, the thermal conductivity largely depends on what material was used in its production.

fire resistance

Aerated concrete, due to its structure, does not support combustion and does not spread fire. By visiting any construction forum, you can be sure that, according to reviews, masonry of aerated concrete blocks with a thickness of only 20 cm is quite capable of stopping the spread of fire.

Foam concrete also belongs to non-combustible materials and is able to withstand one-sided exposure to fire for 5–7 hours.

Price

Aerated concrete, especially autoclaved, is significantly more expensive than foam concrete or cinder block. This happens for the simple reason that was already mentioned earlier - foam concrete can be produced almost everywhere. You can even produce it simply by reading reviews and visiting a construction forum, where they will not only help you understand the production technology. A video of the production process can also be offered by people visiting a similar forum, and with good advice, if anything, they will help.

Equipment for the production of autoclaved aerated concrete is expensive, only large enterprises can afford it. Therefore, this material is significantly more expensive.

Dimensions

The size of the foam block and brick

Just one foam or gas block can replace 15–20 bricks in a masonry.

At the same time, the wall of the house made of these materials will be much lighter. The concrete blocks themselves can be produced in various sizes. It all depends on the equipment on which this building material is produced.

Houses made of foam and gas blocks compare favorably with brick houses, primarily at a lower cost. During their construction, both the foundation and the masonry and the material itself are cheaper. Among other things, such houses will be cheaper and maintain. It is much easier to heat a room with walls made of cellular concrete.

What is better for construction?

Any forum where the intricacies of construction are discussed can accommodate enough supporters and opponents of the use of both materials. Some prefer accessibility, simplicity and low cost of production. The second nicer good old brick and cinder block. Others believe that the quality of construction can only be guaranteed if materials produced in large-scale production with expensive equipment are used. Both the foam and the gas block deserved both negative and laudatory reviews. Each material has its own undoubted advantages and shortcomings.

Advantages and disadvantages of aerated concrete and foam concrete

In addition to the production process, using the video, you can appreciate the simplicity and subtleties of laying walls made of foam concrete and aerated concrete. Simplicity and convenience of this process play far from the last role.

The choice of material for construction can be influenced by many factors. The price consists of the cost of the material itself, the cost of its installation, performance, availability, purpose of the building being erected, and much more.

When building a house it is important to choose the right material, which will be strong enough, light and at the same time be able to keep warm in the house. Among the building materials for private construction, the most popular are gas blocks and foam blocks. The difference between them, at first glance, is insignificant, but their technical performance is significantly different.

Comparative characteristics of foam blocks and gas blocks

Foam concrete and aerated concrete refer to cellular concrete, and they have a similar structure. But due to the different raw material composition and production technology, cellular blocks have different properties and technical characteristics. It is important to weigh the difference between a gas block and a foam block for the correct choice of building material. The difference between them must be carefully studied.

The main indicators by which these building materials differ, for ease of analysis, are summarized in the table.

Technical indicators	Foam block	gas block
Color	Gray	White
Surface structure	Smooth	Rough
Grade by density	700, 800, 900	350, 400, 500, 600, 700
Strength	Class B2.0 at D800	Class B2.0 at D500
Durability	70 years old	50 years. Because it modern material was not possible to test experimentally
Vapor permeability	Below	Above
Thermal conductivity	Higher, but in the case of this indicator, this is a disadvantage for the walls of the house	Below
masonry	Laying is carried out on a cement-sand mortar with a joint thickness of 10 mm. This promotes the formation of cold bridges.	masonry gas blocks performed on a special glue. The thickness of the seam is 1 mm, which eliminates the formation of cold bridges
Geometric parameters	Production is carried out in molds and deviations can reach 5 mm.	The autoclaved gas block is cut on modern equipment and the deviation of dimensions from the norm is ± 1 mm
Shrinkage	3 mm/m	The shrinkage process takes place in an autoclave, so it does not exceed 0.1 mm / m
Due to the greater specific gravity, the load on the foundation is higher	Below
Ease of work	Harder due to more weight	Easier, because easier to work with light material
Soundproofing	Below	Above
Ease of processing	More difficult	Due to the lower density of the material, it is easy to saw
Environmental factor	4	2
moisture resistance	Above	Below
Frost resistance	Below	Above
fire resistance	high	high
Price	Below	Significantly higher

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All about foam blocks

Foam blocks are made of foam concrete, which formed by mechanical mixing of the concrete mixture with foam. Thus, the weight of the material is significantly lightened. The pores of the foam blocks are closed, which contributes to increased moisture resistance.

Components of foam blocks:

• sand;
• cement;
• water;
• foam.

Specifications:

• dimensions foam blocks and gas blocks are the same - 200x300x600 mm;
• weight one block of the appropriate size - 22 kg;
• density
• water absorption - 14%;
• frost resistance - 35 cycles;
• compressive strength - (0.25 - 12.5) MPa;

Advantages of foam blocks:

Their disadvantages:

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All about gas blocks

Aerated concrete blocks are made in autoclaves from aerated concrete. It is formed due to a chemical reaction, as a result of which gas is released. In the structure of aerated concrete, many small cracks are created under the action of the outgoing gas, so this material permeable to air and moisture.

Components of aerated concrete:

• cement;
• quartz sand;
• lime;
• water;
• aluminum powder;
• chemical additives.

Specifications:

• dimensions aerated concrete blocks - 200x300x600 mm;
• weight one block of the appropriate size - 18 kg;
• density material - (300 - 1200) kg / m3;
• water absorption - 20%;
• thermal conductivity - (0.1 - 0.4) W / m * K;
• frost resistance - 35 cycles;
• ultimate compressive strength - (0.5 - 25) MPa;
• material consumption - (21 - 27) pcs / m3.

Advantages of gas blocks:

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Manufacturing technologies for these materials

The process of creating foam concrete blocks:

1. In industrial concrete mixer cement and sand are poured in the required proportion. All components necessary for the manufacture of the product are pre-weighed. Depending on the proportional ratios of sand and cement, the strength grade is determined from D400 to D1000. The higher the brand of foam concrete, the stronger and more massive the material.
2. The required amount of water is added to the dry mixture to obtain a solution of the desired consistency.
3. The composition is kneaded until a homogeneous consistency is formed.
4. When the solution is ready, foam is added to the industrial mixer.
5. The cement-sand mixture is mixed with foam.
6. After the solution is ready, it poured into molds.
7. After filling in the form, stand up to 4 hours, during this time the primary setting occurs.
8. After 4 hours, the forms are loaded and taken to a place where the foam concrete will dry in natural atmospheric conditions. Behind three weeks the material reaches sufficient strength for the construction of the supporting structures of the building.
9. The remaining strength is gained over the next six months. In the future, the strength of the material only increases. This process lasts for 50 years of operation.

Manufacturing technology of aerated concrete blocks:

Separately, we note that the equipment for the manufacture of blocks of aerated concrete is quite complex and expensive.

Having studied what gas blocks and foam blocks consist of, their technical characteristics, production technology and differences, it is easier to decide what to build a house or cottage from. What material to choose for the construction of the building foam block or gas block depends on technical requirements and financial opportunities the future owner of the house.

Didn't find answers in the article? More information on the topic:

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Aerated concrete or foam concrete what is the difference

Before you build a house, you need to decide what to build it from. It is the material chosen that determines how strong and comfortable the home will turn out to be. good walls and heat will not be given out to the street, and extraneous noise will not be allowed to enter the rooms. And they must be environmentally friendly and fireproof. Now at the peak of popularity, light and durable cellular materials for walls. Often, the developer thinks for a long time what to buy: aerated concrete or foam concrete - what is the difference between them. At first glance, it does not exist at all. And let's take a closer look.

Understanding terminology

Aerated concretes are lightweight cement-based materials. Their feature is the presence of numerous cells, due to which the material acquires many useful properties both physical and mechanical. Cellular concrete has several varieties. In addition to the foam concrete and aerated concrete already mentioned above, there is, for example, aerated concrete. Porous concrete can be autoclaved and non-autoclaved.

According to the method of formation of these cells, materials such as:

• aerated concrete;
• foam concrete;
• Aerated concrete.

According to the method of hardening, porous concretes are divided into:

• The autoclave method involves curing the material at elevated pressure in a sealed tank to which saturated water vapor is added.
• The non-autoclave method assumes that the material hardens in a natural environment. At the same time, it is heated by electricity. It is also possible to treat concrete with saturated steam. But, unlike the previous method, the pressure does not increase.

Foam concrete and aerated concrete are quite significantly different from each other. They have different composition and characteristics. And in operation, both materials manifest themselves in completely different ways.

Features of the production of foam blocks and gas blocks

1. To make foam concrete, mix the cement base with special additives. They are necessary for foaming the mass. These foaming agents are both based on synthetic substances and organic. The foamed mass falls into special forms, where it hardens in a natural environment. The result is foam concrete blocks. The material, called monolithic, is not poured into molds, but into formwork. After hardening, the removable formwork is dismantled. Fixed formwork remains in place.

Structure of foam concrete.

2. There is a significant difference between foam concrete and autoclaved aerated concrete. The latter, unlike foam concrete, can only be made under production conditions. In order for it to foam, no special chemical additives are needed. Aerated concrete consists of natural substances - water, cement, lime and gypsum. A certain amount of aluminum is also added to it - in the form of powder or paste. It is this substance that promotes gas formation.

Aerated concrete is produced in a special container - an autoclave. To give the material strength, it is subjected to high pressure and temperature, as well as water vapor. During the production process, a chemical reaction occurs between the components, and a substance with new properties is formed. And its crystal lattice is similar to the lattices of some organic substances. These are, for example, calcium silicates, in particular, tobermorite. The chemical reaction is accompanied by the release of hydrogen - it is this gas that makes the material porous and fills these same pores.

The structure of aerated concrete.

When the aerated concrete finally hardens, it's time to cut it into neat identical blocks. For this, strings are used that provide an almost perfect even cut. Due to this, when laying blocks of aerated concrete, the seams are very thin. So cold bridges, through which a lot of heat can go outside, can be avoided.

Video: Production and differences between aerated concrete and foam concrete

Compare the characteristics of foam concrete and aerated concrete

GOSTs for the manufacture of both materials are the same. Deviations from them are not allowed. It would seem that the characteristics of both porous concretes should coincide. In fact, there are differences.

Moisture absorption and frost resistance

The difference in manufacturing technologies affects these two parameters. So, aerated concrete absorbs water like a sponge. Because of this, during frosts, he does not manifest himself in the best way. Foam concrete has much lower water absorption. But it should be remembered that usually walls made of cellular materials are not left "as is" - they are covered with a protective layer. It can be plaster, siding or tiling. So in practice, you can not take into account the difference in water absorption. But you can know that aerated concrete loses here.

Video: Aerated concrete sinks or floats

What is stronger

The density of both porous concretes can vary from 300 to 1200 kilograms per cubic meter. If we compare aerated concrete and foam concrete of the same density, it turns out that the latter is less reliable and strong. In addition, the strength of this material directly depends on the quality of the foaming agents. Since a good blowing agent is expensive, some manufacturers cheat and replace it with a cheaper one. The strength of foam concrete is also unstable over the entire surface of the block. But the aerated concrete block is homogeneous and manifests itself equally at all points.

Environmental Safety

During the production of autoclaved aerated concrete, a reaction takes place between lime and aluminum. The hydrogen released as a result is by no means all released during the solidification of the material. Part of this gas (however, quite a bit) can come out during construction, and then, when the walls of the house are already folded. But hydrogen does not belong to poisonous gases, therefore it does not produce a toxic effect on the human body. Blowing agents that form foam concrete, both proteinaceous and artificial, also harmful substances do not contain. In addition, the pores of foam concrete are closed and airtight. It turns out that both of these materials do not have significant environmental deficiencies, and this parameter cannot be decisive in the choice of one or another material.

Video: Is it true that aerated concrete is poisonous and banned in Europe

Which material is more susceptible to shrinkage

Cracks may occur in a wall made of foam concrete blocks. After all, the shrinkage rate of this material is from 1 to 3 mm / m. Aerated concrete blocks practically do not crack, since they have a similar parameter - no more than 0.5 mm / m.

Ability to retain heat

The denser the structure of cellular concrete, the worse its thermal insulation ability. Therefore, foam concrete, which has a low density, is a better heat insulator than aerated concrete. But load-bearing walls cannot be laid out of it - it is not strong enough. Therefore, it is necessary to use a denser material, but make the walls thicker, because its thermal conductivity is higher. For example, for Novosibirsk, the walls of a house made of foam concrete blocks D600 should be no thinner than 65 centimeters. Then the house will be warm enough.

If, under the same conditions, lay walls of aerated concrete, then they will turn out to be no thicker than 45 or 50 centimeters. And the density at the same time will be sufficient D 400 or D 500. As you can see, aerated concrete is much better able to retain heat, and the wall from it is lighter and stronger. However, it is up to you to decide whether to use aerated concrete or foam concrete for your home.

fire resistance

Both materials perform well in this respect. And these cellular concretes pass air well, and also contain only substances of natural origin. They are lightweight and easy to use. As for resistance to frost, aerated concrete in this regard is twice as reliable, and sometimes even three times more reliable.

Compare the cost

Foam concrete is much cheaper - about 20 percent. After all, the components for its manufacture are not very expensive, and the equipment is not complicated. But during construction, it may need more than aerated concrete. Therefore, you should not look only at the price of a cubic meter of material - first, calculate the entire project of the future home.

It is also important that aerated concrete is laid on an adhesive mixture, and inexpensive cement mortar is quite suitable for foam blocks. True, with glue, styling is faster, and you will need it much less than cement mixture. As a result, it turns out that the cost of laying foam blocks (including all materials) exceeds the cost of laying gas blocks. Besides, thin layer glue, unlike cement, does not give cold bridges. As a result, the house is more energy efficient.

Compare sizes

Since aerated concrete blocks are manufactured in the factory, their dimensions are more stable than those of foam blocks. After all, foam concrete can be made right on the construction site - with the help of special installations. As a result, both the consumption of materials for laying and the convenience of laying itself are different for both cellular concretes. But this does not mean that aerated concrete is a winner on all counts.

We hope that this comparison of the advantages and disadvantages of foam concrete or aerated concrete was timely and helped you. Good luck building!

Video: Which is better? Aerated concrete or foam concrete?

You will be interested

srbu.ru

Gas block or foam block - what to choose?

Similarities and differences of materials

The gas block or foam block is chosen based on the fact that these are similar building materials and they belong to lightweight concrete, they differ only in the way the air cells are formed in the block itself.

Layout of the foam block device.

Air bubbles in the foam block are formed using foam, which is mixed with concrete. The result of which, after the concrete has dried, is a block of the appropriate size, the foam in which is frozen in the form of air bubbles. This block is durable, light and warm. The cells of the foam block have a closed type structure, that is, when solidified, air bubbles envelop the concrete. As a result, all bubbles are enclosed in concrete. You can buy foam blocks here, on the website mi-2.ru.

Gas block and foam block are porous materials that absorb moisture, but this happens when completely immersed in water. If they are simply left on the street, moisture absorption will not be critical, in which case the comparison of the gas block and the foam block will lead to the same result. The most important thing during construction is the proper organization of the drainage system; water must not be allowed to stagnate in the area of ​​\u200b\u200bthe basement and foundation.

To create air bubbles in the gas block, aluminum chips are used, which, when heated, react with oxygen and release gas. The result is aerated concrete. In aerated concrete, the cells have open type, that is, air bubbles interact with each other. Gas blocks are usually produced industrial way, they are dried in an autoclave. To form a block, string cutting is used, which can provide correct form, which makes the laying of blocks of high quality and speeds up the process.

The density of the foam block is 600-700 kg / m 3, and the density of the gas block is 400-500 kg / m 3. Therefore, the foam block will be stronger.

The statement that the strength of a block depends on its density is absolutely true. But we must remember that a significant role in the strength of the block is played by the good quality of cement. If slag or low grade cement is used (use cement grade 400 instead of 500), the quality will be affected. Moreover, in the private production of foam blocks there is no way to check the quality of concrete, and large plants producing aerated concrete, the quality of cement must be checked in the factory laboratory.

Ecology and economy

The foam block is an environmentally friendly material.

Aerated concrete contains aluminum, which has unhealthy properties, and the foam block is an environmentally friendly material.

During production, aluminum chips are introduced into aerated concrete in the ratio of 400 g/m3. This is necessary for the formation of air bubbles, particles of aluminum powder react with the hydroxo groups of the solution, converting aluminum oxide into oxygen. The released oxygen swells the gas mass almost twice by volume; metallic aluminum does not remain in the composition of aerated concrete.

Aluminum oxide is present in aerated concrete, it gets there with cement and other components of the gas block. If we compare the aluminum content in a conventional brick, it has up to 400 kg of oxide, which is found in simple clay, and in the foam block, the content of aluminum oxide is 50 kg. Therefore, it makes no sense to worry about the fact that aluminum is included in the composition of the gas block.

Cement mortar for a foam block is usually applied with a layer of 1 cm, and masonry for a high-precision gas block has a thickness of 2 mm. The difference in this case in the volume of material can be 5-6 times. Glue for the gas block, respectively, will need 6 times less. And it is only 2 times more expensive than cement mortar. Considering that the foam block is cheaper than the gas block, then laying on glue is not more expensive, and even a little cheaper than laying on cement mortar.

There are two types of technology for the production of cellular concrete: non-autoclave and autoclave.

What is done with the help of an autoclave is called aerated concrete. The porosity of this material is formed by a chemical reaction. It consists of lime, cement and aluminum powder.

The foam block (non-autoclave block) consists of the same components as concrete (sand, cement, water), plus a foaming agent.

http://youtu.be/oQ-jkHBKrzI

These materials are made according to one DSTU or GOST, as they have similar technical and physical characteristics.

Production of concrete blocks

Table of production of aerated concrete blocks.

Aerated concrete is produced by large enterprises, given the complex process of its manufacture.

Foam concrete is easier to manufacture, which is why portable equipment for its production has recently appeared. Since the cost of such equipment is low, people who are far from the basic concepts of strength, density and thermal conductivity began to manufacture this material. This pretty much spoiled the reputation of the foam block. But this is an excellent material that has certain advantages and is not inferior to the gas block in its properties.

When buying a foam block, you need to contact serious manufacturers who have been on the market for more than a year, who have a quality certificate, conduct laboratory tests, observing the technology and working with cement of a brand of at least M500.

The gas block is distinguished by more accurate dimensions, and the technological requirements are most carefully observed, since it is produced in the factory. Foam concrete is often made directly on construction sites where it is difficult to meet impeccable technological requirements.

Due to the difference in production technology, foam concrete and aerated concrete are frost-resistant and absorb moisture differently. Gas blocks absorb water more easily, and, naturally, their frost resistance is lower. Both the foam block and the gas block need a protective and decorative finish with siding or facing bricks to increase their service life, thanks to which this problem is reduced to zero.

Comparison of foam concrete and aerated concrete

Table of characteristics of aerated concrete and foam concrete.

It can be noted that the gas block, in comparison with the foam block, has a more “strict” geometry (permissible deviations). This eliminates problems when laying gas blocks using cement-adhesive mortars. Consequently, it reduces the gaps and gaps between the blocks, and therefore the "cold bridges" are minimal.

An aerated concrete block is aerated concrete cut into pieces. And aerated concrete is a porous, artificially created stone obtained by curing the mixture in an autoclave. The mixture consists of a hydraulic binder, a finely dispersed silica component, a blowing agent and water. It differs from other building materials in its extreme strength and lightness.

If desired, you can also make gas blocks yourself. Equipment for this production is sold freely and almost everywhere.

First of all, foam blocks and gas blocks differ in production technology.

Lime, cement and sand are dosed and mixed in a special mixer, then water and aluminum powder are added to them. Then the mixture is poured into a mold and kept for several hours. During this time, a chemical reaction takes place in the mixture, in which carbon dioxide is released.

Due to the interaction of aluminum with water, pores appear in the material and, consequently, the total volume increases. At this time, the material "seizes" or gains initial strength.

After "setting" a kind of half-baked mass is formed. On a special installation, blocks are cut from it. The remaining excess mass is collected and re-sent to production. Sliced ​​gas blocks are fed into autoclaves and steamed for several hours at 180 ° C and a pressure of 11.5 atmospheres. During chemical and physical processes that occur during steaming, gas blocks gain 100% strength. In the final phase, the gas blocks are stacked on pallets and packed in plastic to prevent moisture from entering.

Foam concrete production

Scheme of the production of foam concrete.

Cement and sand are poured into an industrial mixer, then water is added. The mass of each ingredient is determined by preliminary weighing. Depending on the proportions of cement and sand, the strength grade for future blocks is set: D400-D800, D1000. The higher the brand of the block, the stronger, stronger and heavier it is. The resulting solution is stirred until a homogeneous solution of concrete is formed. Then foam is added to the industrial mixer where the solution was mixed. And then the concrete solution mixed with foam is poured into molds.

Foam concrete after pouring stands for 4 hours, at which time the initial setting occurs. Then the blocks are loaded onto pallets and sent for further drying. Under natural atmospheric conditions, foam concrete blocks dry for 2-3 weeks. During this period, foam concrete blocks acquire performance required for laying floors and walls. Foam concrete reaches the main share of strength within the next 6 months.

The minimum set of equipment for the manufacture of foam blocks includes:

• installation for the production of foam concrete;
• foam generator, foam mixer;
• pumps and compressor equipment;
• molds for the production of foam blocks.

If we compare high-quality gas blocks and foam blocks, aerated concrete has one advantage: at an early stage, at the same density, it is stronger, but inferior to foam concrete in all other parameters. If you choose aerated concrete, then it must be borne in mind that it has maximum strength at the time of manufacture, and then this indicator slowly decreases.

In concrete, strength development takes decades. That is, at the time of production, foam concrete or concrete products have the lowest strength, which will further increase.

Foam block or gas block

Foam concrete differs from aerated concrete in a closed porosity structure, air bubbles are separated from each other inside the material. In aerated concrete, air bubbles communicate with each other, therefore, having the same density, foam concrete floats in water, and aerated concrete sinks. Thus, due to the lack of water absorption, foam concrete has high frost-resistant and heat-shielding characteristics. Due to these qualities, it is worth choosing foam concrete for use in places with high humidity and at “heat-cold” joints, where condensation forms. Aerated concrete blocks are unacceptable for use in such places. This requires the use of special technologies and high-quality performance of such work.

Foam concrete is an environmentally friendly material. This is another of its advantages over aerated concrete. The main material used in the manufacture of aerated concrete is quicklime(aggressive, chemically active substance). Reacting with aluminum powder, it releases gas, which, in turn, forms gas bubbles in the structure of aerated concrete.

With strict observance of the technology, quicklime enters into a chemical reaction and is “extinguished”. It is practically impossible to achieve this in production, therefore, there is always unreacted lime in aerated concrete. The consequences of this are most clearly seen in poor-quality bricks, in the production of which lime is used. The surface of such a brick is covered with small chips and dents, with white small dots, the cause of which is lime. When exposed to moisture, it is extinguished, generates heat, increases in size and destroys the brick. Processes like this also take place inside the material. With foam concrete, this is impossible, since it does not contain quicklime.

Advantages of the foam block

1. Heat. Due to the high thermal resistance, the foam block building is warmer. During operation, this allows you to reduce heating costs by 20-30%.
2. Microclimate. The foam block prevents significant heat loss in winter. Foam concrete blocks are not afraid of dampness, they allow you to avoid high temperatures in summer and adjust the air humidity in the room by releasing and absorbing moisture. This contributes to the creation of a positive microclimate.
3. Fast installation. The low density and lightness of foam blocks, the impressive size of the blocks in comparison with bricks several times allow you to increase the speed of laying. Ease in the processing of foam blocks and their finishing, the ability to make holes, channels for pipes and electrical wiring. Elementary laying of foam blocks.
4. Soundproofing. Foam concrete has a high ability to absorb sound. Buildings made of foam blocks are provided with current requirements for sound insulation.
5. Environmental friendliness. During the operation of foam blocks, toxic substances are not emitted and in terms of their environmental friendliness they are second only to wood.
6. The beauty. Due to the ease of processing, corners, arches and various pyramids can be made from foam blocks. different shapes.
7. Profitability. The high accuracy of the geometric dimensions of the foam blocks makes it possible to lay the foam blocks on glue, prevent “cold bridges” in the wall and significantly reduce the thickness of the outer and inner plaster. In comparison with standard heavy concrete, the weight of foam blocks is 10-87% lower. A fair reduction in weight leads to solid savings on the foundation.
8. Fire safety. Foam blocks prevent the spread of fire and have the first degree of fire resistance. Therefore, foam blocks are suitable for use in the construction of fire-resistant structures. When exposed to intense heat, such as a blowtorch, the surface of the concrete does not explode or split, as does heavy concrete. Therefore, the fittings are protected from heating for a longer period. Tests have shown that foam blocks 150 mm thick protect against fire for 4 hours.
9. Transportation. Favorable ratio of volume of foam blocks, weight and packaging makes building structure convenient for transportation.

Concrete strength ratio table.

When a vapor-forming component is added, a reaction occurs, which is accompanied by the release of gas, from which the mixture becomes porous, resulting in the formation of cellular aerated concrete. There is another method in which foam agents are added and concrete mix foamed mechanically.

The foam block is almost ageless and virtually eternal material, not afraid of the effects of time. It does not rot, has the strength of a stone. High compressive strength allows the use of foam blocks in the construction of products with low volumetric weight, and this increases the thermal resistance of walls made of foam blocks.

Comparison table of the main physical and technical indicators.

By appointment, aerated concrete and foam concrete are classified as structural and heat-insulating materials. Blocks are cured in natural conditions. It is recommended to use foam blocks for laying internal and external walls, partitions in buildings with a relative humidity of no more than 75%. Blocks for walls with a wet regime in basements, as well as where strong wetting of concrete is possible or an aggressive environment exists, should not be used without the use of water-repellent coatings. It is recommended to use blocks for self-supporting and bearing walls in buildings with a height of up to three floors, but not more than twelve meters. The number of floors in buildings in which blocks are used to fill non-bearing walls or frames is not limited.

Foam block or gas block are building materials with a low density, which determines lighter walls, in comparison with brickwork. This reduces the load on the foundation and reduces labor costs, predetermining the low cost of the construction object.

Concrete, brick and wood are the most popular building materials. In the construction of houses, aerated concrete (foam concrete) blocks, which combine the best properties of these materials, are now gaining more and more solid positions.

So, comparing foam concrete and aerated concrete, we can conclude that each of them is good in certain conditions.

o-cemente.info

which is better, warmer and stronger

When building a house, it is necessary to use materials that guarantee the strength and longevity of the erected structure. One of the most popular are "light" concretes - foam concrete and gas block, the differences between them are insignificant at first glance, but the technical properties differ.

Consumers, choosing materials for construction, first of all, distinguish those that have the following properties:

• Reliability;
• Durability;
• Frost resistance;
• moisture resistance;
• Thermal insulation.

These are the main indicators that are guided by when buying; such a factor as profitability is also often taken into account.

Cellular concrete meets these criteria, it is presented in various types. In this article, we will focus on foam concrete and aerated concrete, find out what the difference between a foam block and aerated concrete is, consider the characteristics of materials and be able to compare the foam block and aerated concrete according to the main indicators.

Foam and aerated concrete is a kind of "light" or cellular concrete, the body of their blocks is saturated with air bubbles, which lighten the weight of the material and retain heat.

Depending on the density index, they are divided into three types:

• Structural;
• Thermal insulation;
• Structural and heat-insulating.

Aerated concrete and foam concrete, despite the similarity of the structure, have a different composition and method of manufacture, so their characteristics differ from each other. Let's carefully consider gas blocks and foam blocks, the pros and cons of the material and choose the best option.

Characteristics of gas blocks

The porosity of aerated concrete blocks occurs during the reaction of a blowing agent - aluminum powder with lime under the influence of high temperature and pressure in an autoclave furnace.

During the reaction, a gas arises, which, when released, forms a network of microcracks and bubbles in the body of the block. The resulting cells are open and freely pass air, which has a positive effect on the vapor permeability of the material.

Composition of aerated concrete

• Portland cement brand not lower than M400;
• Fine sand;
• Lime;
• Water;
• Aluminum powder or paste;
• Chemical additives and plasticizers (if necessary).

Advantages of aerated concrete blocks

The advantages of aerated concrete include the following properties:

• Durability - manufacturing takes place in an autoclave method, which guarantees high strength and longevity;
• Lightness - the presence of voids in the structure of the block makes it noticeably lighter in comparison with ordinary concrete;

• Ease of processing - aerated concrete does not require special tools for additional processing - cutting, drilling, sawing, etc.;
• Low thermal conductivity - gas blocks keep heat perfectly, the room warms up quickly and cools down slowly;
• Fire resistance - blocks withstand up to 8 hours of exposure to fire, while maintaining technical characteristics;
• Sound insulation - voids in the body of the block absorb noise;
• Biostability - aerated concrete is not subject to damage from the effects of fungus, mold, insects and rodents;

Cons of aerated concrete

Among the negative properties stands out poor resistance to moisture. Gas, in the manufacture of blocks, formed a network of microcracks in the structure of the block, which absorb and conduct water. Therefore, during construction, it is necessary to think carefully about the waterproofing of the structure.

Developers also note low bending strength and difficulty in fixing additional elements. To hang a shelf or cabinet on a wall of gas blocks, you need to use special fasteners.

Characteristics of foam blocks

Foam concrete is formed by mixing cement mortar with a special foam, which, when the blocks dry, forms many closed cells. The composition of the foam blocks includes sand, cement M400, water and foam.

It is necessary to evenly distribute the foam so that the structure of the block has a uniform composition.

Advantages of foam blocks

The advantages of the material include:

• High rates of thermal insulation;
• Light weight - reduces foundation and transportation costs, easier to move and build;
• Strength - load-bearing walls up to three floors are erected from foam concrete;
• Breathability - foam concrete does not interfere with natural air circulation, a comfortable microclimate is created in the room;
• High resistance to temperature extremes and frost;

• Fire resistance - foam blocks do not burn, withstand more than 4 hours of open fire, without loss of properties;
• Environmental friendliness - the composition of foam concrete includes only safe materials that do not emit toxic substances;
• Resistance to the occurrence of fungal and mold lesions;
• Moisture resistance.

Minuses

The disadvantages of foam concrete blocks are:

• Structural shrinkage - up to 3 mm per meter of wall;
• The need for waterproofing - foam concrete, like any cellular concrete, does not tolerate moisture well;
• The need to use special fasteners - ordinary nails and oakels do not hold well in a foam concrete wall;
• The opportunity to purchase low-quality goods - foam blocks are not difficult to manufacture, therefore handicraft production is widely developed.

Block comparison

Let's compare the foam block and aerated concrete according to the main criteria, and find out what is better to build a foam block or aerated concrete from.

Thermal insulation - which is warmer foam block or gas block? The thermal conductivity of both materials is quite high, there are no significant differences.

Strength - What is stronger foam block or gas block? The strength of aerated concrete is higher, this is due to the method of manufacture. Aerated concrete blocks harden under the influence of high temperature in an autoclave, and foam concrete dries naturally.

So what is stronger gas block or foam block? Definitely a gas block, aerated concrete of strength grade B500 has a strength class of B2, for a foam block this class has blocks with a brand of D800.

Geometry - there is no fundamental difference in shape and size, manufacturers produce blocks of different shapes depending on the scope of the material.

Gas blocks are distinguished by accuracy and evenness of lines, the deviation from the norm is not more than 1 mm, since the material is cut in production. And the foam block cannot boast of these, the dimensions of the foam concrete can deviate up to 5 mm.

The speed of construction - the dimensions of the foam block and the gas block can reduce the time by several times, and the light weight reduces the load on the foundation.

Biostability - both materials are not subject to the appearance of fungus and mold formations. They also have indicators of durability, fire resistance and sound insulation on the same level.

Vapor permeability - the air exchange indicators of a gas block are significantly higher than those of a foam block, due to the openness of the pores.

Moisture resistance - foam concrete has the best performance, but aerated concrete absorbs water like a sponge, so thorough protection is necessary.

Profitability - the cost of an aerated concrete block and a foam block is different, building a house from aerated concrete will cost much more. This is explained by the fact that the production of aerated concrete is possible only at the plant using special equipment.

Masonry and finishing - ordinary cement mortar is suitable for a foam block, this is not acceptable for gas blocks. For aerated concrete, only a special adhesive solution for cellular concrete is used; a deep penetration primer and gypsum-based plaster are also used for its finishing.

Shrinkage - structures built from foam blocks are subject to shrinkage, approximately 3 mm / m, aerated concrete does not suffer from this, since complete hardening occurs in an autoclave oven.

Main indicators of materials

Specialists and developers leave a lot of positive and negative reviews about foam blocks and gas blocks, which can affect consumer opinion. To make sure the information is true, we not only examined, but also compared foam and gas blocks, which is better to choose for yourself.

Which material to prefer depends on the purpose of use and financial condition. For example, when choosing a foam block or a gas block for a garage, you can take foam concrete, but for the construction of a residential building it is better to use aerated concrete.

betonov.com

Comparative characteristics of gas block and foam block. What material is better? +Photo

In this article, we will try to figure out together which material is better for building a house - gas block or foam block.

And help us with this Comparative characteristics the main qualities of these materials.

We will learn the secrets of the technology for the production of aerated concrete and foam concrete, what determines the cost of the material, and what professionals advise you to choose.

New materials for building houses

In the modern construction market with an enviable frequency, new materials for the construction of houses appear. Among them are gas block and foam block, which made a kind of revolution in construction.

Although, this is not surprising, because the materials have remarkable qualities that make the process of building buildings easy.

Gas block or foam block, which is better?

This question, for sure, is asked by site owners when they are faced with the choice of materials.

Let's try to figure out what characteristics each of these building materials is endowed with, and which one should be preferred. In this case, it is important to take into account the opinion of experienced developers, and not use word of mouth. People's opinions can differ, and quite radically.

Features of the manufacture of aerated concrete and foam concrete

These materials are made from raw materials with a high environmental friendliness, and are included in the category of lightweight concrete.

It is quite difficult for non-specialists to distinguish these materials in appearance, because they are very similar. But, their production technology is different. Even the formation of pores in blocks occurs as a result of different technological procedures.

Foam block production

The production technology includes several stages:

The equipment that is used for the production of foam concrete is very affordable, and even beginners in this field can afford it.

Quite often, small firms are manufacturers of foam blocks.

This leads to the fact that the original product does not have an attractive appearance and proportional shapes, which forces builders to adjust each block in size during the construction of the house.

Gas block production

Manufacturing steps:

Given the complexity of the technological process, gas blocks for building a house are produced mainly at specialized factories, which in turn affects the final cost of the product. He a priori can not be cheap. But, building houses from a gas block is a pleasure, and the process itself takes a little time, because nothing needs to be cleaned, cut, adjusted to size.

Components

Composition of foam concrete

• Blast furnace slag and waste from other production processes.
• Lime.
• Water.
• Lime.
• Cement.
• Soapy or sulfide liquor (gives the blocks a recognizable porosity).

Note. Air bubbles in foam concrete are obtained due to the reaction of the concrete solution and the foam former. They represent the closure of a cell filled with oxygen.

Out of ignorance, many are afraid to buy gas blocks due to the presence of aluminum powder in the composition. But, experts say that it is not in the final product, and the harm comes from the component in its pure form.

Composition of aerated concrete

• Sand is quartz.
• Cement.
• Water.
• Aluminum paste.
• Lime.

How to distinguish a foam block from a gas block?

You can distinguish a foam block from a gas block by the size of the pores. At the gas block they are small, at the foam block they are larger.

The color of aerated concrete blocks is white, the surface has roughness and relief. The foam blocks are smooth to the touch and have a gray tint. Knowing these nuances will help beginners to distinguish between these two materials in appearance.

Important! Before buying foam concrete blocks, be sure to ask about the availability of a quality certificate so as not to buy a pig in a poke.

Foam blocks due to closed pores have excellent heat and sound insulation qualities. In addition, the material does not absorb water, but at the same time needs to be treated with special water-repellent compounds.

The gas block for building a house, which has small pores with microcracks, is more susceptible to the damaging effects of moisture, so the blocks must be covered with waterproofing substances.

The strength and reliability of each of the materials can only be judged in practice. As the theory says, strength is directly proportional to the density of the material. But in fact, even fragile at first glance, aerated concrete is in no way inferior in strength to the foam block.

Important! The heat conductivity coefficient of a gas block at a density of D 500 is 0.12, a foam block with a density of D 700 is 0.24.

What is better aerated concrete or foam concrete?

The opinion of experts is unambiguous - the best material for the construction of housing for permanent residence, as well as other types of buildings, is a gas block. Since he managed to establish himself as a reliable and durable material.

Although aerated concrete cannot boast of good heat retention properties, but thanks to its wonderful geometric shape and frost resistance, this shortcoming can be made up for by using a high-quality cement-adhesive composition during masonry. In addition, a kind of monolithic masonry allows you to reduce the penetration of cold masses to a minimum.

Foam concrete has good heat retention performance, but in order to build warm housing, it is necessary to make thick masonry walls, which will entail the purchase more material. As a result, the gas block holds the palm with the same wall thickness.

Aerated concrete and foam concrete are used mainly in low-rise construction. Foam concrete is more often used for load-bearing walls no higher than the 3rd floor, different type partitions.

Aerated concrete is ideal for the construction of load-bearing walls, they close the spaces between the frame in monolithic structures, and also build partitions. Also, gas blocks are suitable for building houses above 3 floors, subject to the use of stiffening belts.

Very often, the pricing policy of the material affects the answer which is better gas block or foam block. But, in any case, before making a final decision, you need to analyze all the features and nuances of using these building materials.

Above, we have already described the production technology of each material, and concluded that the cost of building a house from gas blocks is higher.

It is important to take into account the fact that financial costs should pay off with the durability of the house, elementary installation and low consumption of additional materials. All this is possible when using aerated concrete.

What can be said about useful qualities foam concrete? If you are willing to spend more time looking for proportional blocks of foam concrete, having a desire to save money on material, professional builders will build a strong house for you, and it will cost less than from a gas block.

In addition, you can save the family budget on heating during the cold season, because foam concrete perfectly retains heat. As a result, houses from aerated concrete are warmer than from foam concrete with equal wall thicknesses.

Installation of ventilated facades and proper insulation at home, will create a favorable climate in the house.

Results. comparison table

What is the market price and where to buy?

1. Aerated concrete blocks - buy in the online store construction yard, go>>
2. Aerated concrete blocks - buy in Petrovich, go to the online store>>
3. Building blocks in Leroy Merlin, go to online store>>

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domsdelat.ru

difference, characteristics, which is better to choose?

For the construction of residential buildings, garages and outbuildings widely used concrete blocks with a cellular structure. They are distinguished by high thermal insulation characteristics, low weight, increased dimensions and allow you to complete the work in a short time. When planning construction activities, the owners analyze the properties of materials, trying to choose the best option. One of the frequently asked questions is what better foam concrete or aerated concrete. We will try to understand and give a detailed answer to it.

Foam block or gas block - which material to prefer

Both foam concrete and aerated concrete are common varieties of porous concrete, the distinguishing feature of which is the cellular structure of the concrete mass. At a superficial examination, blocks made of foamed concrete and gas-saturated composite are identical.

The choice of material for building a house

They have a lot in common:

• light weight;
• increased volume;
• fire safety;
• frost resistance;
• thermal insulation properties.

Despite many general characteristics, there are fundamental differences related to the following points:

• the ingredients used;
• the specifics of the manufacturing process;
• strength properties;
• features of the cellular structure;
• degree of moisture absorption.

In addition, there are differences related to appearance, features of masonry materials, their shrinkage, as well as a number of other distinctive points.

Private developers and professional builders are constantly debating on the topic: "A foam block and a gas block - which is better." Trying to answer this question, they cannot come to a consensus. In order to give an objective answer to the question of the fundamental differences between building materials, we compare their characteristics, production process, performance properties, and cost.

Foam block and gas block - which is better

The difference between a foam block and a gas block within the framework of the technical process

Having set out to compare the foam block and the gas block, we will consider in detail the technological moments that affect the method of forming cavities in the concrete mass. Gas-filled blocks are produced by the autoclave method at industrial enterprises, and foam concrete products are manufactured using a simplified technology and harden naturally. Fundamental differences in the properties and structure of composites are caused by the components used for manufacturing, as well as by the features of the technology.

How does a gas block differ from a foam block in composition

Aerated concrete block includes the following ingredients:

• portland cement marked M400, the concentration of which reaches 50% of the total volume of the mixture;
• sand fraction based on quartz, which is a filler and is introduced in the amount of 30-40%;
• lime in an amount of 10–25%, which is involved in the chemical reaction of gas formation;
• aluminum powder, which promotes vaporization and is introduced in an amount of not more than a tenth of a percent;
• calcium chloride and calcium silicate introduced into the working mixture as special additives.

To ensure the required consistency, water is added, heated to 50 ºC. The technology allows the introduction of special modifiers that affect the strength characteristics of the composition.

The amount of ingredients introduced into foam concrete products is determined depending on the required specific gravity of the blocks. The simplified technology makes it possible to obtain products with a density of 0.35–1.25 t/m³.

Cement brand M500

The composition of the mixture includes the following components:

• cement brand M500. Added as a binder;
• sand of medium size. It is possible to replace sand with expanded clay;
• foam additives. Their number determines the porosity of the product.

The amount of sand exceeds the volume of cement three times for foamed composites with increased bulk density.

What is the difference between a gas block and a foam block according to manufacturing technology

To decide which material to use for construction - aerated concrete or foam block, consider the manufacturing methods:

• aerated concrete composites are made only in production conditions on special equipment. The manufacturing technology of products provides for high-temperature treatment of the concrete composition in closed tanks, in which performance properties are achieved under the influence of high pressure. The formed aerated concrete array after hardening is cut into products of various sizes and shapes, which allows expanding the range of products;
• the manufacture of foamed composites does not require the use of special equipment and can be carried out in small enterprises, as well as by private traders. The filling of the working mixture is carried out in special forms that determine the dimensions of the products. When mixing the foaming agent with the working mixture, a cellular structure of an array with closed pores is formed. The process of hardening of the foam concrete composition occurs in cast molds at a temperature corresponding to the ambient temperature.

The laboratory quality control system operating at industrial enterprises guarantees the conformity of the characteristics of the manufactured aerated concrete products. Privately produced foam concrete composites may differ significantly from the requirements of the standards. When purchasing aerated concrete, foam concrete and other types of block materials, pay attention to the availability of certificates of conformity.

Aerated concrete composites are made only in production conditions

Foam block and gas block - the difference in cells

Despite the fact that both building materials have a cellular structure, the shape of the air pores is different:

• in the aerated concrete mass, the pores formed as a result of the chemical reaction of aluminum powder are evenly distributed throughout the volume and have an open shape. Gas-filled building material, like a sponge, intensively absorbs moisture. Aerated concrete blocks absorb up to 50% of liquid with a corresponding increase in mass. Increased hygroscopicity significantly reduces thermal insulation properties, causes cracking of unprotected blocks when they freeze;
• foam concrete products are distinguished by a closed form of air inclusions, which occupy up to 80% of the total volume. Air cavities with a diameter of 4–5 mm are unevenly located in the foam concrete mass, which is caused by the peculiarities of the distribution of the foaming agent. This reduces the strength of the material. However, the closed cell configuration contributes to the resistance of the foam concrete mass to moisture absorption. It is not difficult to verify the hydrophobic properties of foam concrete blocks - the material immersed in water does not sink.

The porous structure is easy to see during visual inspection. In addition, the products have different colour. The gas-filled composite containing lime has White color, and foam concrete blocks - gray.

What is the difference between a foam block and a gas block - we compare the characteristics

Comparison of the characteristics of materials will help answer the question of what better foam block or gas block.

When talking about aerated concrete and foam concrete blocks, you can often encounter the fact that not everyone understands well what kind of materials they are and what is the difference between them. Aerated concrete and foam concrete are united by the fact that they belong to cellular concrete, i.e. have a porous structure. This provides them with high performance in terms of thermal insulation properties, ease of processing and use, good strength and reliability, and, most importantly, a relatively low price - after all, a brick wall will cost much more. But aerated concrete and foam concrete also differ from each other, which is due to some differences in their manufacture, hence the difference in some technical properties. It is impossible to say exactly which material is better, but we hope that after reading this material you will form the correct conclusion for yourself.

Features of the production of foam concrete blocks

The most important differences between foam concrete and aerated concrete should be sought in the technology of their production.

So, foam concrete blocks are obtained by adding special foaming additives of organic or synthetic origin to an ordinary cement mortar. Foam is formed on the basis of water, and the water itself evaporates naturally during the drying process. Foaming additives foam the concrete, thereby filling it with air bubbles. Such bubbles are distributed throughout the entire volume of concrete, and after hardening, they make it much lighter, adding heat-insulating and sound-proofing properties.

Such a process can be carried out right at the construction site, since especially specific and high-tech equipment is unnecessary. Due to the shapes used in the manufacture of the foam block, finished products may differ in size, sometimes by 10-20 mm.

Features of the production of aerated concrete blocks

To obtain aerated concrete, quartz sand, lime, cement and water are required, as well as a special component - aluminum powder, due to the presence of which bubbles are formed that fill the aerated concrete. The process of solidification of the mixture takes place in autoclaves at a sufficiently high temperature and high pressure, and not in natural conditions, as is the case with foam concrete. And since special equipment is used for production, all the characteristics of the future aerated concrete block can be controlled, making them the same throughout the entire volume. This cannot be said about foam concrete, which, while hardening on the street, may have a slightly heterogeneous and unequal structure and properties. And the shape of the gas blocks produced in this way is ideal, has minimal deviations from each other, which cannot be said about foam concrete, for which forms are often used that are not capable of ensuring accuracy and evenness.

Such processing allows aerated concrete blocks to have a number of other advantages over foam concrete, which we will discuss later.

Advantages of aerated concrete over foam concrete

1. Strength- this is the main advantage of aerated concrete. With the same density, aerated concrete is much stronger than foam concrete. And if we compare blocks with the same strength, then, naturally, aerated concrete will have a lower density, which means it will be easier and more convenient in construction. By the way, it is believed that foam concrete can shrink and microcrack after construction is completed, so it is useful to wait at least a year after building a house from foam concrete blocks before starting expensive repairs and decoration.
2. Aerated concrete blocks have the best vapor permeability. It's all about, again, the structure of the material and the method of production. So, in aerated concrete, all the pores are interconnected, which cannot be said about foam concrete, where they are isolated. Therefore, an aerated concrete block passes moisture and air better, and the microclimate in such a house will be much better than if you use foam concrete, which passes air much worse. That is why, if you decide to insulate a wall of aerated concrete blocks, then it is better to use breathable materials so as not to negate all the advantages of aerated concrete. And foam concrete blocks can also be insulated with foam plastic to reduce the cost of work.
3. Now oh thermal conductivity. It is believed that aerated concrete and foam concrete are capable of providing approximately equal thermal insulation performance. But if you look into some details, you can understand that the thermal insulation of foam concrete does not always meet the values ​​declared by the manufacturers. The fact is that the pores in foam concrete, as a rule, different sizes: it can be 1 mm, or it can be 5 mm, while in aerated concrete the pore size is usually constant. It follows from this that the value of thermal conductivity may differ in different places of the block. But this is not as scary as the fact that under conditions of high humidity, the thermal conductivity of foam concrete can increase significantly, which will lead to the fact that the walls simply will not keep the temperature that is comfortable for residents. Yes, and more powerful wall insulation will also have to be spent. Although there are many experts who can argue with this fact.
4. Aerated concrete blocks are often called environmentally friendly material - this is true, because nothing is used in production except natural materials which have already been mentioned above. In the production of foam concrete blocks, synthetic blowing agents can be used, which can no longer be called environmentally friendly. Here it is impossible not to mention the myth that aerated concrete contains aluminum, and it is harmful to our health. It is pointless to argue about the harmfulness of aluminum - it is harmful, but is it available in ready-made aerated concrete blocks? All the aluminum reacts with the lime, eventually liberating oxygen and forming aluminum oxide: oxygen is needed to form pores, and aluminum oxide is harmless and is found in most building materials, even in clay. Yes, and the aluminum oxide itself in aerated concrete is less than in foam concrete and in brick. And here, not everything is clear: there are opinions that aluminum still remains in the material, not completely spent on the reaction, but still we remain of the opinion that aerated concrete is more environmentally friendly.
5. The form aerated concrete blocks are almost perfect, and the error is no more than 2 mm, so it is very easy to work with them, the walls are smooth, and you need a little glue. Foam concrete blocks can have such significant deviations in size that it will be noticeable to the naked eye, and it will be more difficult to correct such irregularities, much more mortar will be needed.
6. Mounting aerated concrete blocks will cost you relatively less than foam concrete. This is due to the fact that glue is used for laying aerated concrete, and its thickness is much less than the thickness of the cement mortar for foam concrete (2 mm versus 1 cm). Even taking into account that glue is 2-3 times more expensive than cement, and its consumption will be about 6 times lower, we get savings, not to mention the fact that when using glue for aerated concrete, there are practically no cold bridges, which makes the house more comfortable and warmer.
7. Aerated concrete blocks are much easier in the subsequent decorative processing, this is largely due to the fact that they have excellent geometry.

Advantages of foam concrete over aerated concrete

conclusions

From everything written above, it follows that, according to some characteristics, foam concrete and aerated concrete blocks are similar, while foam concrete is cheaper. Thus, foam concrete may be suitable for a certain type of construction, where some of its shortcomings will not fail. Aerated concrete, on the other hand, has more attractive properties compared to foam concrete: largely due to production technology. And besides, if you calculate all the installation costs, then the construction of aerated concrete blocks may not be at all more expensive than construction from concrete blocks. The final choice is made by everyone before the start of construction, but in most cases the use of aerated concrete blocks remains justified.

In recent decades, cellular concrete has become widespread in construction, a porous material based on cement and mineral fillers. Belongs to the group of lightweight concrete. Aerated concrete and foam concrete products belong to cellular concrete.

These materials are quite close to each other in their properties. By external signs, it will be difficult for a non-specialist to distinguish one from the other, but still there are differences and quite significant.

aerated concrete- a building material with a cellular structure. Produced by autoclave curing. It is used for the manufacture of external load-bearing walls and internal non-bearing walls and partitions. When reinforcing it is used for floor slabs. Excellent material for thermal insulation.

- one of the types of cellular concrete. Produced from cement, mineral fillers and a foaming agent. It is used in domestic and industrial construction as a foam block or monolithic foam concrete. It has good performance for thermal insulation.

Structural features of cellular materials

Composition of aerated concrete

For the production of aerated concrete blocks are used:

• cement: is an astringent;
• quartz sand, gypsum, lime, ash, slag, waste from metallurgical production: used as mineral fillers;
• pure aluminum powder: is introduced into the general composition in the form of a paste or suspension.

As a result of chemical reactions, aerated concrete acquires a cellular structure in the form of closed, evenly distributed throughout the volume, spheroid cavities with a cell size of 1 ... 3 mm. Internal pores do not communicate with each other.

Composition of foam concrete

For the manufacture of foam concrete are used:

• cement, - is used as a binder;
• washed sand, - is used as a mineral filler;
• blowing agent, - most often they use artificially produced liquid wood-saponified resin.

Due to foaming additives in the composition of the mixture, closed with water, pores are formed that do not communicate with each other. The internal structure of foam concrete is affected by additives in the initial mixture and compositions of foam concentrates.

If we compare the products in the section, then with the naked eye it will be seen that foam concrete has larger internal pores compared to aerated concrete. In addition, the cell sizes in the latter are characterized by a smaller variation in size than in foam concrete.

According to the color difference, aerated concrete has a light, almost white tint, foam concrete has a light gray color scheme.

If we compare the surface of the products, it can be seen that the foam block has a smooth surface, while the gas block has a relief rough structure.

Methods for the production of cellular products

aerated concrete

The stages of production of aerated concrete products consist of:

1. Measured dry ingredients are mixed with water and mixed through mechanical devices. The process time is determined by the technological map.
2. The finished mixture is poured into molds. In this case, an aqueous solution of cement with fillers forms an alkaline medium, which interacts with fine aluminum powder. The result of a chemical reaction is gaseous hydrogen, which actually foams the cement slurry. Due to the released gas, the volume of the mixture increases (yeast dough can serve as an analogue).
3. After the period allotted for setting the cement mixture, the resulting workpiece is removed from the mold and cut into intermediate semi-finished products - blocks, panels, slabs.
4. Finishing carried out in autoclaves or electric ovens. According to these methods, aerated concrete is called:

1. • "autoclave", - aerated concrete products are processed for a fixed technological time in an autoclave with water vapor at a certain temperature and pressure;
   • "non-autoclave", - gas blocks are subjected to the drying process in special electric drying chambers.

These procedures give the aerated concrete final technical properties.

Stages of production of foam concrete:

1. Dry ingredients are mixed, dissolve in water.
2. A foaming agent is introduced into the finished solution. The resulting mixture is subjected to mixing until a homogeneous composition is obtained. In the process of mechanical action, physical and chemical reactions occur, as a result of which free masses of gas are formed in the form of individual bubbles. The gas component gives the composition a porous structure.
3. The resulting solution is poured into molds and aged for 6 ... 12 hours c, - until the cement sets. The resulting products are released from the forms for further drying, which is carried out in a place protected from rain.
4. Technological strength for use in construction foam blocks are purchased after 15 ... 30 days.

Aerated concrete is produced in the factory, which predetermines high quality components and products derived from them.

The foam concrete production technology is simpler, which predetermined the possibility of its production by private individuals and small organizations. Moreover, production can be organized directly on the free area of ​​the construction site.

But such simplicity affects the quality of products:

• mistakes are made with the choice of components for mixtures;
• often mixtures are not balanced in composition;
• time limits are not observed when mixing components, drying semi-finished products;
• the geometric dimensions of foam concrete products are performed with unacceptable deviations from the required ones.

In this regard, when choosing a supplier, it is necessary to carefully read the product documentation, clarify the production conditions, and, if possible, visually inspect the finished product.

Technical characteristics and applications of cellular concrete products

aerated concrete

If we compare aerated concrete and foam concrete in the field of application, then it is advisable to use the first one in critical work, mass construction in both industrial and domestic construction. The foam block is good in small construction production - it is used for the construction of country or low-rise houses, it is used for the construction of shelters for livestock, agricultural premises.

This alignment can be explained by the quality and properties of the material, the conditions of its production, the price of a unit of production.

Geometric dimensions. Comparison

In order to perform an analysis on the geometry of a gas block and foam block, it must be remembered that the first is produced only in the factory; the second - allows handicraft production. Industrial products from both materials have tight tolerances - the discrepancy in length does not exceed 1 ... 3 mm. Private production "sins" with a discrepancy in size - even in one batch, the run-up reaches 10 ... 20 mm.

Based on this, foam concrete products, sinning with dimensional accuracy, should be used only for irresponsible construction - for garden houses, sheds, garages, auxiliary outbuildings and other similar buildings.

The strength of the gas block and foam block

When comparing strength characteristics, products of the same size are taken. In this case, it is necessary to take into account the conditions for the production of foam blocks. For the purity of the experiment, it is advisable to use products manufactured in the factory.

Despite the apparent lightness of the gas block, it turns out to be 10 ... 40% stronger than the foam block. Naturally, this takes into account the grade of the material.

In addition, the foam block has a high expansion coefficient and can shrink, which causes microcracks to appear over time.

Minus the gas block - increased hygroscopicity. The structure of the material does not prevent the penetration of moisture into the product, which requires additional finishing works to improve the waterproofing properties of the erected structure.

Economic indicators, price differences

A gas block, which has approximately the same dimensions and characteristics, costs 20 ... 100% more than a foam block. This is due to the materials used, the equipment used, transport and production costs. But this is an incomplete analysis.

If we take into account the full consumer properties of materials, durability, installation technology, then in general it turns out that the gas block is, in economic terms, more profitable than the foam block.

Naturally, in the analysis it is necessary to take into account the object being built, - during construction garden house and a multi-storey structure, the economic result, per given unit of production, may be opposite.