Aerated concrete or foam concrete

Building materials with a porous structure are gaining popularity. They are durable and lightweight, used for the construction of private houses, country cottages, economic and commercial buildings, garages. For this, foam concrete and aerated concrete are more often used, but you need to know what is the difference between these two concretes that are similar in technical characteristics.

Foam concrete and aerated concrete are building materials that are gaining popularity because they have sufficient strength and low thermal conductivity. The porous structure reduces the density and mass of blocks made from them. The air-filled cells explain the thermal insulation. Despite the similarity of characteristics, the scope of these compositions varies.

Strength, low specific density of foam concrete increases the service life of this material. Therefore, it is used for residential buildings - houses, cottages, household structures, baths. The only limitation in the use of foam concrete is that buildings erected from it should not be higher than three floors. It is used in the device:

bearing walls of buildings and structures;
interior walls for space planning;
fences, fencing areas;
floors with steel bar reinforcement.

The uniformity of the structure of aerated concrete explains one of its main features - increased resistance to cracking and shrinkage of structures created from it. This allows it to be used for the construction of household buildings, industrial, public and commercial facilities. It is used for:

interior partitions;
filling spans in frame buildings;
load-bearing structures and walls;
multi-storey structures and buildings.

Production technologies and composition

To understand how aerated concrete differs from foam concrete, you need to understand the technologies by which these building materials are made. During the production process, an internal porous structure is formed at the calculated density and strength - characteristics that determine the main advantages. At the same time, components that are harmless to health are used, which significantly expands the scope of such concretes.

Foam concrete production

Foam concrete is produced using a simplified technology, available even at home. The components for production are: cement, water, sand, slag and other fillers. The main substance - providing the porosity of the material structure - sulfite liquor. For foam concrete you will need: Portland cement 36%, sand 47%, 16% water. Foam additives and fibers to increase strength do not exceed 1%. Production stages:

All ingredients are thoroughly mixed in dry form, after which a small amount of water is added to them.
A foaming component is added - sulfite liquor. Stirring is continued until a homogeneous structure is achieved. During chemical reactions, gas is released, as a result of which the material acquires a porous structure.
The prepared solution is placed in the prepared formwork in the form of the required blocks or structures. Foam concrete sets in 10 hours, the minimum time is 5 hours. After removal from the formwork, the blocks are laid outdoors or in a dry room for final drying.
The necessary strength, allowing the use of this material, is achieved in 14-21 days.

It is important to pay attention to the quality of the formwork so that the dimensions and surface of the blocks or structural elements meet the technical requirements.

Aerated concrete production

Aerated concrete is produced at industrial enterprises with special equipment. Cement, quartz sand and lime, water are used as the main components. The foaming component is aluminum paste. The composition is similar to that used for the preparation of foam concrete. A pure substance carries an environmental hazard, but it is completely neutralized during the production process. Stages of production of aerated concrete:

The components are poured into the concrete mixer in proportions and filled with water, kneaded to a homogeneous consistency, according to a previously developed technological map. The added aluminum paste, sometimes powder, reacting with the solution, saturates it with gas, creating a cellular structure and at the same time being neutralized.
The resulting solution is poured into pre-prepared forms. It should be borne in mind that as a result of the reaction of aluminum compounds, its volume will increase during setting.
The frozen monolith is removed from the molds and cut into blocks, slabs, lintels, and other elements of the desired size.
To improve the strength and waterproofing characteristics, the resulting products are processed in autoclaves under steam at 12 bar or high temperature electric furnaces.

The resulting aerated concrete and materials from it have increased strength, correct geometry.

Feature Comparison

The main components and production technologies are largely similar, but the technical characteristics of these materials differ. The difference between the properties of foam concrete and aerated concrete is explained by their structure and appearance.

Foam concretes are structured with relatively large cells with low moisture absorption, good sound and heat insulation. The surface is relatively smooth, the color is gray.

Aerated concrete has smaller cells, as a result of the formation of gas in the thickness of the solution, microcracks may appear on the surface. They have good water and vapor permeability, thermal insulation characteristics. Rough white surface requires additional finishing.

The density of aerated concrete is in the range from 400 to 800, foam concrete - a higher density from 400 to 1200 kg / m³. Differences in other specifications:

Aerated concrete has more stable thermal conductivity, since it has a uniform cellular structure. The pores in foam concrete have a diameter of 1-3 mm, they are distributed unevenly, so the thermal conductivity of this material is unstable.
The strength of treated aerated concrete is significantly higher than that of foam concrete.
Industrial production allows you to get aerated concrete blocks with precise geometry, privately made foam concrete blocks do not have such properties.
The plaster lies on both materials, but the correct geometry of the aerated concrete elements saves. Also, aerated concrete has better adhesion.
Aerated concrete has better frost resistance, like autoclaved or heat-treated concrete. This indicator for foam concrete reaches 35 cycles of freezing and thawing, and aerated concrete with hydrophobic fillers can withstand up to 75 cycles.

If we compare the performance of foam concrete and aerated concrete, then aerated concrete has best performance, allowing its use for the construction of various buildings and structures, including multi-storey ones.

Advantages and disadvantages

Aerated concrete and foam concrete have their own advantages and disadvantages. What is better to use in a particular situation can only be determined after analyzing the properties of these materials. Among the advantages of foam concrete note:

Relatively low thermal conductivity.
Relatively low density, which allows you to save on the foundation, lay out the walls yourself.
High levels of sound insulation.
The optimal size of blocks and other structural elements speeds up construction.
Ease of fitting elements with a simple hacksaw.
Environmental friendliness allows the use for the construction of any residential premises.
Long-term operation even in difficult conditions, corrosion resistance.

But this material also has disadvantages:

The porosity of the structure gives fragility, especially at the edges of structures, the strength of foam concrete is unstable.
Unattractive outer surface, which is better to plaster.
When erecting foam concrete structures, reinforcement is required at the junctions of elements.
With handicraft production, the quality of the material is reduced.
The use of this material requires careful calculations of the strength of the structure.
Foam blocks do not have the correct geometry, since they are not produced in industrial conditions.

The advantages of aerated concrete include the following characteristics:

Reduced density with increased strength.
Increased moisture resistance of the autoclave block.
Fire resistance.
Frost resistance.
Resistant to biological influences and corrosion.
Durability allows buildings to operate for more than 100 years.
Excellent indicators of heat and sound insulation.
Ease of processing.
Savings, since aerated concrete requires a minimum amount of cement.
Environmental Safety.
The correct geometry, since the structural elements are made in production.

With all the advantages of the material, it also has disadvantages:

Increased hygroscopicity requires additional plastering.
Accuracy is required when calculating loads, since blocks can crack.
The cost of this material is higher than foam concrete.

Results

When choosing foam concrete or aerated concrete, you need to weigh what is best for construction. These materials have much in common, but there are differences that do not allow them to be used in the same way. Obviously, aerated concrete has the best strength indicators, they are similar in other characteristics. Therefore, specific calculations, features and budget of the work are taken into account, as a result of which a decision is made.

Today on the market there is a large number of various building materials. And among the most popular building materials are blocks of cellular concrete. They are quite widely demanded both among home masters and among specialists.

From honeycomb lightweight concrete To date, two types of blocks are being produced: foam block and gas block. In this article, we will consider what to choose: aerated concrete or foam concrete.

Due to the large distribution of building materials on the market, many home craftsmen are trying to figure out which is better than aerated concrete or cinder block, not forgetting about such a popular building material as foam concrete.

These materials are characterized by almost the same chemical composition.

The common components are:

Sand.
Water.
Cement.

Due to the same composition, aerated concrete and foam block have the following advantages:

Resistance to the influence of various biological factors (rotting, damage by rodents, etc.).
Fire resistance.
Ease of installation. If you know the principles brickwork, then you do not need instructions for building a wall from a gas block or foam block with your own hands.
Resistant to active chemicals.

What's the Difference?

Consider the manufacturing technology of these materials:

It is these differences in production that influenced the properties of these materials.

Characteristics of foam blocks and gas blocks

To determine which better blocks- foam blocks or gas silicate, first of all, you need to compare their characteristics. Despite technological progress, today there are no ideal building materials, so you need to choose all the time by comparing the advantages and disadvantages of different blocks.

Determining which is better, aerated concrete or foam block, we will compare materials according to the following characteristics:

Let's consider these points in more detail.

moisture resistance

A good house must be dry. And foam concrete in this case will be an ideal building material, since it almost does not absorb moisture.

Suggestion: to make sure in good water resistance foam block, you can make such an experience. Place the block in a container of water and leave for a long time. The block will float on water, both in a day and in a week.

Due to such a high hygroscopicity, experienced builders advise waterproofing only the outer walls of the house, which are lined with foam blocks.

Aerated concrete is also waterproof, however, to a slightly lesser extent. At the same time, the drying of this material takes longer.

A warm home is the dream of many our compatriots. Given the harsh winters, anyone wants to forget about drafts, cold and heating appliances that are placed throughout the home.

Walls built of cellular concrete require insulation, especially external. Aerated concrete is characterized by a lower thermal conductivity, but thermal insulation is still a mandatory process.

As for sound insulation, isolated pores in foam blocks create better sound insulation than aerated concrete. But soundproofing these walls is still necessary.

Strength

In our country, we have long been accustomed to doing everything “for centuries”. Given the cost of modern building materials, this desire is quite easy to justify. Therefore, a durable building material for load-bearing walls is required.

The gas block has a higher strength than the foam block.

Aerated concrete blocks better hold external loads, as a result, they do not crumble and do not lose their shape during loading and unloading. That is, the house comes out more durable.

Thus, when the material needs to be processed - choose a foam block, if you need a house with strong and even walls - choose aerated concrete.

Wall masonry

Consider, what is better foam block or gas silicate during masonry and what is the difference, since ease of use is an important indicator for every home master.

Foam blocks are not afraid of rain, no cold. Immediately after production, they are ready for use. Therefore, work can begin immediately upon the arrival of building materials.

At the same time, gas blocks absorb moisture, so they should be used in masonry walls only after drying. However, plaster lays better on this material, which greatly facilitates the execution of finishing work.

Reinforcement

Rebar laying in foam concrete walls prevents the formation of cracks. Due to their lower strength, this process is mandatory. Aerated concrete walls also require reinforcement, but in this case, reinforced blocks are laid only in the ceilings of window and door openings.

Dimensions of foam blocks and gas blocks

Since aerated concrete blocks are made in industrial conditions, their dimensions are much more stable, unlike foam blocks. Since foam concrete can be made directly on construction site- with the help of special installations. As a result, both the convenience of masonry and the consumption of masonry materials themselves differ for both cellular concretes. However, this does not say at all that aerated concrete - wins on all counts.

Fare

When deciding which gas silicate blocks or foam blocks are better, you should not least of all pay your attention to the difference in transportation costs, since the delivery of building materials to the construction site is a mandatory step, since building a house will require a significant amount of building materials.

Foam concrete blocks are less resistant to transportation. Requiring high-quality masonry, when transported on bad roads, they can receive a minimum of damage. Gas blocks are stronger, but, as a rule, are transported in covered vehicles to prevent moisture from entering.

fakes

Deciding what better foam blocks or gas blocks, not many home craftsmen think that today it is very easy to stumble upon a fake on the market when buying building materials of dubious quality. And if the manufacture of aerated concrete blocks excludes these cases in the bud, then easy-to-manufacture foam blocks are often faked by one-day companies and small cooperatives.

Industrial production of aerated concrete products is possible only with the purchase of expensive specialized equipment, because all building materials of this type meet all quality standards.

At the same time, on modern market there is a lot of low-quality foam concrete. And in addition to low cost, these building materials can have a number of other, more unpleasant indicators, among them low environmental friendliness and increased brittleness.

Facts and misconceptions

Today there are a number of questions on these building materials, of interest to many home masters:

How harmful is aluminum in aerated concrete to human health? These experiences are completely groundless, since aluminum, being one of the most popular materials on earth, is also found in the traditional ceramic brick. At the same time, its mass fraction in brick is much higher than in aerated concrete. This material does not have any harmful effects on the human body.
For laying the foam block, cement mortar is used, while the gas block is placed on glue. Will laying a gas block be cheaper due to saving the solution? During the laying of the foam block, the layer cement mortar is at least 1 cm. The adhesive layer when constructing a wall of gas blocks is only 2 mm. Naturally, the consumption of glue will be 5 times less, and its price is only 2 times higher than the cost of concrete.

With the development of the idea of energy saving, alternative building materials have received a rebirth, in particular wall blocks. For the construction of walls, foam blocks and gas blocks, which are varieties of cellular concrete, are increasingly being used.

Their main similarity is their porous structure, which improves performance in comparison with classic ceramic bricks.

Foam concrete block - fake diamond with a porous structure, consisting of sand, cement, water and a synthetic foaming agent.

Aerated concrete block - a cellular artificial stone, consisting of cement, quartz sand, blowing agent (aluminum paste or suspension), water, gypsum or lime.

1. Foam block and gas block: what is the difference?

Already from a short definition of the concepts, it can be seen that, despite the similar composition, the materials have a significant difference in manufacturing technology. Hence the completely different structure of internal pores.

Comparative analysis by key parameters is presented in the table:

Options	Foam block	gas block
Cell structure	has closed pores, providing excellent heat and sound insulation	has a fine-cellular structure with microcracks after the release of gas, allowing the material to "breathe"
Production technology	a) mechanical mixing of the components and the foaming agent - the difficulty in obtaining a structure that is homogeneous in density; b) drying and curing in natural conditions.	a) the interaction of components through a chemical reaction - the ability to control the process; b) drying takes place in autoclaves under high pressure and temperature.
visual perception	a) a gray tint; b) smooth surface; c) when split, large pores are visible; d) a fragment remains on the surface when immersed in water.	a) white color; b) surface with roughness; c) when splitting a pore with a diameter of less than 1 mm; d) a fragment in a container with water quickly sinks to the bottom.

There is an opinion about the difference in the geometry of the blocks, which is not always true. More often than not, materials made in different ways are compared. So, if we compare the foam blocks produced by the cassette method (molded) with cut gas blocks, then the former will be inferior in dimensional accuracy. The cassette method is common in small handicraft factories. Used in large scale production high tech, allowing to maintain the accuracy of the parameters, regardless of the type of material.

There are no differences in environmental safety. It is based on natural materials, and chemical reagents either decompose during the reaction or become non-toxic.

2. What are the sizes of foam concrete and aerated concrete blocks?

The construction of walls and internal partitions from blocks is accelerated, in part, due to the relatively large size of the building material unit. The increase in geometric parameters, relative to the classic brick, became possible due to a decrease in the weight of the porous material. But even here there are limits regulated by GOST: the maximum size of one foam block in mm is 625x500x500.

Foam concrete blocks with a length of 600 mm, a height of 200 and 300 mm, a thickness of 100 (for partitions), 200 and 300 mm are in demand on the market. The exact dimensions are specified in GOST. Enterprises that produce cut blocks have the opportunity to fulfill orders with individual requirements for dimensions.

Gas blocks are in demand in the following sizes: length 600 or 625 mm, height 200 or 250 mm, thickness 100, 150, 200, 250, 300, 350 and 400 mm.

In the cheap production of blocks, the cassette method is used, in which the concrete mixture is poured into a mold with partitions. With this method, the deviation in size can be up to 5 mm.

When choosing a suitable option, the height and length are compared with the perimeter of the wall being erected for ease of masonry, and the thickness directly depends on the load and the required level of thermal insulation.

3. How much do foam blocks and gas blocks cost?

The cost of building materials is an important argument in favor of one or another type. Especially when it comes to similar technical characteristics. But you need to understand what to compare. There will be a strong bias in prices when comparing products of different quality. Foam blocks of handicraft production using outdated technology will be noticeably cheaper than gas blocks from a plant with advanced equipment. But this approach will not be useful, since saving means losing quality.

Let's analyze the price of certified products from major manufacturers with a good reputation. The price of blocks depends on the brand of strength and size.

In Moscow and the Moscow region, the cost of one wall foam block of the D600 brand and 600x300x200 in size from different manufacturers ranges from 100-115 to 160 rubles. At the same time, 1 m 3 costs 2900-3750 rubles.

The price of heat-insulating and structural aerated concrete wall blocks of the D500 brand and 600x300x200 in size in Moscow and the region starts from 110-112 rubles. per piece, and the upper limit is at around 167-175 rubles. per piece 1 m 3 contains 27.8 blocks, respectively, the average price of 1 m 3 gas blocks is 3058-3700 rubles.

The price of blocks in remote regions (Siberia, the Far East), as well as other building materials, will be on average 1.5 times higher than in the Central region. In addition, during construction, to increase thermal insulation, thicker walls must be laid.

The budget also needs to include the cost of paying for masonry services. On average, 1 m 2 of a wall of cellular blocks costs 1500-1700 rubles. The price list of contractors indicates the cost per cubic meter, which varies from 2400 to 4000 rubles.

4. Specifications: which is warmer and more durable?

Specific technical characteristics are available in the product card on the manufacturer's website or in the accompanying document for the supplied lot. The most significant indicators are strength and the ability to maintain a comfortable temperature for living.

The structure of blocks of different densities: structural and heat-insulating (D600) and heat-insulating (D300).

The thermal insulation of cellular concrete is due to the presence of a system of pores filled with air. According to this indicator, foam blocks with closed pores win. But if we consider cheap option with poor geometry, requiring laying on cement mortar, then because of the "cold bridges" the foam concrete wall needs additional insulation.

Aerated concrete blocks often have exact dimensions and are laid on an adhesive composition, so the finished aerated concrete box creates a better microclimate (keeps warm in winter and cool in summer). If we compare walls made of foam block and gas block on glue, then in the first case, thermal insulation will be better.

The strength of the material depends on the density, while the density has a negative effect on thermal insulation (the higher the density, the higher the thermal conductivity). Based on the density kg / m3, the blocks are divided according to their purpose: heat-insulating D300, D400, D500; structural and heat-insulating D600, D700, D800 and structural grades D900 and higher.

When comparing aerated concrete and foam concrete of the same strength grade, the first density will be lower. Autoclave production technology ensures the output of high strength blocks.

In relation to moisture, gas blocks with open pores and a rough surface are comparable to a sponge. In areas with frequent floods, aerated concrete houses are impractical and short-lived. Foam blocks are more resistant to the environment and absorb water more slowly when immersed in it. Water absorption in foam concrete is half that of aerated concrete. However, the porous structure of the material, one way or another, requires moisture protection.

5. What are the main pros and cons of foam blocks and gas blocks?

General pros and cons of wall blocks and specific ones, peculiar only to a particular type, are presented in the table below.

pros	Minuses
general
environmental friendliness	low load bearing capacity- only suitable for low-rise buildings
light specific gravity	not suitable for storage open sky, after laying, exterior finishing is required
ease of installation and high speed of wall construction	the laying of a capital expensive foundation is implied
high thermal insulation	fragility - at the slightest deformation of the foundation, the walls crack
	needed outer insulation to shift the dew point that destroys the material
for foam blocks
good sound insulation	gradually gain strength - laying begins 1.5 months after manufacture
low thermal conductivity	gives a slight shrinkage of 2 - 3 mm
durability over 30 years	high risk of buying low-quality material
fire resistance
frost resistance 25 - 30 cycles
for gas blocks
ideal geometry - dimensional error no more than 1 mm	lower soundproofing performance
does not shrink	strong water absorption
durability over 55 years	high cost of interior finishing works
frost resistance 50 cycles and more	it is necessary to prime the surface of the walls twice due to the strong absorption of the composition

You can also find other comments on materials on the forums, but most of them are related to the manufacturer’s dishonesty or violations of construction technology.

6. What to put foam blocks and gas blocks on: glue or cement mortar?

Manufacturers of gas blocks indicate the accuracy of the dimensions of the block as an advantage of their products, which allows them to be carried out. This method makes it possible to minimum thickness seams in 2-3 mm and high strength masonry. At the same time, the laying of gas blocks on cement mortar is not allowed, since the material takes a large amount of water, as a result, the laying is fragile. The adhesive for cellular blocks contains water-retaining additives and substances that increase the adhesion of materials.

The exception is the laying of the first row. It is carried out on cement-sand mortar 10-15 mm to compensate for irregularities in the foundation and accurately level the blocks.

For foam blocks, laying is possible both on mortar and on glue. The first option is considered budgetary and is used for the material Low quality with bad geometry. The second one is used for high-quality certified blocks of high accuracy.

7. What kind of foundation is needed for a house made of foam blocks or gas blocks?

In promotional materials, you can find the statement that, due to the low weight of the blocks, the foundation can be lightweight and low-cost. But this gross misunderstanding can lead to irreversible consequences. Porous blocks are brittle and have low resistance to deformation, so they need a reliable monolithic foundation. But this option will not be cheap, and high costs will not always be rational.

To pick up best option for reliability and price, the following factors are taken into account:

soil properties (level ground water, freezing depth, heaving, soil type);
the number of floors in the plan (direct relationship with the load on the foundation);
the volume and complexity of the work (in some cases, an initially simple and cheap option can end up costing more than a monolithic slab).

Before starting work, they collect complete information about the characteristics of the soil on the building site. Errors in laying the foundation will soon be reflected in large cracks on the walls.

Most often used strip foundation and a monolithic reinforced concrete slab, less often a pile-screw foundation.

8. How many blocks are needed to build a house: calculation method

The correct calculation of the required number of blocks for the construction of a residential building will save you from overspending: for an extra volume or for a second delivery when reordering.

The calculation method for a one-story house is as follows:

calculate the perimeter of the outer walls (the sum of the lengths of all sides);
calculate the area of \u200b\u200bthe walls (multiply the perimeter by the height of the floor);
subtract the area of window openings and doors;
determine the volume of masonry (multiply the resulting area by the thickness of the walls);
calculate the quantity in pieces by dividing the volume of masonry by the volume of one block (obtained by multiplying the length, height and thickness);
multiply the resulting number by a loss factor of 1.05;
similarly, we calculate the area of internal load-bearing walls and partitions.

More about the nuances of the calculation with parsing on real examples.

9. Is it necessary to insulate, reinforce or plaster blocks of foam concrete and aerated concrete?

In spite of good performance thermal insulation, porous blocks need external insulation. This is done to shift the dew point to prevent condensation from forming inside the unit. Insulation is also needed in areas with a temperate climate, when laying in two rows is impractical.

In most cases, it is necessary to fill in under the Mauerlat and under the floors with 2-3-story construction, small one-story houses and outbuildings are erected without reinforcement.

To protect against atmospheric precipitation (rain, snow and fog), the cellular material is covered with plaster. Plastering gas blocks is best done immediately on a reinforcing mesh, as there are reviews about the problems of its application. Foam blocks are also plastered to improve aesthetic qualities.

10. What is better foam blocks or gas blocks: popular opinion

On construction forums, these materials have their fans and opponents. The negative is more often associated with the purchase of cheap low-quality material produced using artisanal technology (cast (cassette) foam block and non-autoclaved gas block). Experienced Builders it is advised to purchase certified material from large manufacturers and follow the technology.

Aerated blocks of many are alarmed by the presence of aluminum powder in the composition, so they are considered ideal for non-residential outbuildings. Due to the high hygroscopicity, gas blocks are not suitable for internal partitions of the bathroom, shower room and bathroom. For the same reason, they are not chosen for the construction of a bath.

For a private house, the most successful option is the combination of gas blocks and foam blocks. The first ones go to external walls, and the second - for the construction of interior partitions.

Modern concrete materials with a porous structure are successfully used for the construction of a residential building, a dacha, a bathhouse, a garage and an outbuilding. They have high thermal insulation properties, light weight and easy handling. At the planning stage of the future construction, each owner, analyzing performance characteristics materials, trying to choose a profitable option for himself.

So what is better to use for construction - aerated concrete or foam concrete? To do this, it is enough to compare the materials in order to determine the main similarities and differences between them.

Applications

Foam blocks and gas blocks are one of the most popular building materials with a lightweight cellular structure and excellent thermal insulation characteristics.

Foam concrete has a greater mass, long service life and high strength. This allows it to be successfully used for the construction of low-rise residential and commercial buildings, livestock facilities and outbuildings, the height of which does not exceed 3 full floors. They build from it:

Bearing wall structures.
Internal partitions.
Technical barriers and fences.
Reinforced floors.

Aerated concrete has a constant and uniform structure, resistant to shrinkage and cracking. These characteristics allow it to be used in the mass construction of industrial, commercial and domestic facilities of various types. Often it is used to build:

Partitions.
Bearing walls.
spans of frame buildings.
multi-storey complexes.

Features of the production of cellular blocks

The main difference between aerated concrete and foam concrete lies in the production technology, which allows the formation of an internal porous base of block materials.

Lightweight porous concrete is produced from environmentally friendly components. It is during the production of materials that their unique performance characteristics are formed.

Production of foam blocks

For the manufacture of foam blocks, a more simplified technology is used, which makes it possible to obtain a practical and safe high-quality material.

Dry components are mixed in a prepared container and diluted with a small amount of water.
A foaming agent is added to the resulting mixture. All components are subjected to mechanical mixing to obtain a homogeneous solution. In the process of kneading, the necessary chemical reactions occur with the release of free gases. The gas filler provides the necessary porosity of the material.
The finished solution is poured into special molds and left to fully harden for 5-10 hours. Products are removed from molds and stored to dry naturally in a well ventilated area protected from rain.
The technological strength of the finished blocks is achieved in 2-3 weeks after production.

A distinctive feature of the products are surface irregularities, significant deviations in the geometry of shapes and sizes.

Important! As a basis for pouring concrete mix monolithic formwork can be used. After drying, the base is cut into separate blocks.

Production of gas blocks

Unlike foam concrete, aerated concrete blocks are produced under industrial conditions, which guarantees excellent quality and strength of the material.

Stages technological process:

Dry ingredients in the right proportions diluted with water and mixed until a homogeneous solution is obtained. The duration of the batch is set by the technological map (TK).
The finished solution is poured into molds. In this case, aluminum powder or paste is used as a foaming agent, which enters into a chemical reaction with a liquid cement mortar. The evolution of hydrogen gases contributes to an increase in the total volume of the solution.
After complete hardening, the cement base is removed from the mold and cut into separate blanks in the form of blocks, slabs and panels.
At the final stage finished goods exposed heat treatment using autoclaves or electric ovens. In autoclaves, the blocks are treated with hot steam at a pressure of 12 atmospheres, in electric ovens– drying at high temperatures.

This production technology provides an almost perfect geometry and high strength of gas silicate.

In this regard, the gas block is more preferable than its direct counterpart, since the autoclave production technology provides excellent quality and good performance characteristics of the material. The production of foam concrete does not involve the use of expensive equipment, so the entire technological process can be organized at home.

Comparative characteristics of aerated concrete and foam concrete

Despite the fact that the production of cellular concrete blocks is strictly regulated by uniform state standards, the technical parameters of these materials have significant differences.

Components

Concrete materials are produced using the technology of mixing cement with fillers that provide it with a cellular structure.

Foam concrete is produced on the basis of the following components:

Lime or sand of medium fraction is a mineral filler.
Foaming agent - a chemical additive to create a porous structure.
Water.

The composition of the gas block includes the following components:

Portland cement is a binder.
Quartz sand, gypsum, lime, wood ash, slag waste - mineral fillers.
Aluminum paste or powder - a component for the formation of pores.
Water.

Aluminum foaming agent is a harmful component in its pure form; in the production of aerated concrete mortar, it is completely dissolved in water.

Structure

The difference between aerated concrete and foam concrete blocks lies in their structure and appearance:

Foam blocks: large closed cells with a low level of moisture absorption, excellent soundproofing and heat-insulating properties. They have a smooth gray surface.
Gas blocks: small cells with microcracks formed as a result of gas formation. They are distinguished by good air and moisture permeability, insufficient thermal insulation and require mandatory exterior finish. The material has a relief rough surface of white color.

Strength

Which material is more durable - aerated concrete or foam concrete? This parameter directly depends on the block density.

The density of aerated concrete blocks is from 200 to 600 kg/cu. m, the density of foam concrete blocks - from 300 to 1600 kg / cu. m.

Modern technologies make it possible to create gas silicate concrete with a density of up to 400 kg / cu. m, capable of withstanding the ultimate load, as well as a foam block with a density of over 600 kg / cu. m.

Despite the high density, foam concrete is definitely inferior to its competitor. This is due to the heterogeneity of the structure over the entire area of the material.

Frost resistance

This parameter determines the ability of the cellular material to maintain its performance characteristics during repeated freezing and thawing cycles.

Compared to other porous materials, autoclaved aerated concrete blocks have increased frost resistance, low thermal conductivity and excellent vapor permeability.

For example, due to the special structure, the strong structural Sibit gas block is able to withstand 75 full cycles of freezing and thawing, while for a foam block this figure is only 35 cycles.

Important! When hydrophobic components are added to the feedstock, the frost resistance index of aerated concrete can be increased up to 75 cycles.

Features of use

With many advantages, porous foam concrete widely used for low-rise construction. It is also suitable for the construction of monolithic buildings and structures. In this case, it is used as an insulating or additional material.

Aerated concrete blocks are used as the main structural and thermal insulation material for the construction of objects of varying complexity. The blocks are suitable for arranging heat-resistant and other partitions, filling frame structures from metal and concrete, restoration of dilapidated buildings and the erection of half-timbered structures of residential buildings. Moreover, they can be operated in any climatic conditions.

Price

What is the main difference between foam concrete and aerated concrete? in their market value. With equal technical parameters and dimensions, gas silicate will cost more than foam concrete blocks. This is due to the complexity of the technological process, the high cost of equipment and consumables, as well as significant costs for its transportation.

Foam blocks are produced on cheaper and simpler units that can be located on the construction site.

The market value of aerated concrete blocks is higher, but the production costs are offset by the quality of construction. At the same time, it is economically profitable to build a warm house from aerated concrete due to lower consumption. building material. In addition, the lining of aerated concrete will take less cement mortar than it will take to level the foam concrete blocks.

Table of technical parameters of foam concrete and aerated concrete

The final comparative table shows the main technical parameters that determine the performance properties of aerated concrete and foam concrete. Such a comparison will determine which of the materials should be chosen for the construction of residential buildings and other objects.

Technical specifications	Foam blocks	gas blocks
Filler to create a porous structure	Saponified tree resin	Fine dispersion aluminum
Technological process	By cutting blocks or cassette casting	Single block casting method
Components	Portland cement Lime or medium sand foaming agent	Portland cement Quartz sand, gypsum, lime, wood ash, slag waste Aluminum paste or powder
Equipment for the production of	Factory equipment or do-it-yourself installations	Industrial equipment - autoclaves and electric ovens
Type of pores (cells)	Heterogeneous structure with closed pores	Homogeneous porous structure with external open and internal closed pores
Pore sizes	different size	One size
Block sizes, cm
Height	20, 30, 40	20
By lenght	60	50, 60
By width	10-30	7,5-50
Density, kg / cu. m	300-1600	200-600
Weight, kg / cu. m	300-1600	300-600
Index of mechanical compressive strength of the material	1,2	2,5
Time to gain strength	Gradually with a subsequent increase in strength over 2-3 weeks	Instantly when concrete sets within a few hours
Shape Geometry Accuracy	When cutting a solid base - minor errors. In the production of the cassette method - significant discrepancies. This is the main disadvantage of the material. Up to 25 mm	Minor differences are allowed. This is the main advantage of the material. Up to 2 mm
Moisture absorption level, % (in direct contact with water)	10	45
Frost resistance (number of freeze and thaw cycles)	Average frost resistance - up to 35 cycles	High frost resistance depending on the density of the material - from 35 to 75 cycles. Reducing the level of humidity leads to a significant increase in frost resistance
Soundproofing	high	Low
Environmental indicator	4	2
Thermal conductivity, W/M*k	For thermal insulation - 0.2 For the construction of structures - 0.35	For thermal insulation - 0.1 For the construction of structures - 0.18
External component	Smooth gray surface	Rough white surface
Vapor permeability index, mg/m×h×Pa	0.8 to 0.12	0.15 to 0.23
Life time	No more than 35 years old	Over 60 years
Features of the installation work	Since porous concretes are lighter than solid materials, they are easier to cut, drill, chisel and lay.
Adhesive Requirements	For masonry work, traditional concrete compositions or special adhesive mixtures. Seam thickness - 22 mm	Special masonry compositions are intended for installation. Seam thickness - 3 mm
Additional protection of wall structures	Not required
Degree of shrinkage, mm/sq. m	2-4	0,6
Ability to hold fasteners	The same. The need to use special fasteners designed for porous materials
Cladding material	All available materials	Breathable materials
Thermal insulation material	If necessary, a reliable heat-insulating material is used - mineral or basalt wool
Applying the plaster	For plastering porous substrates, special plaster compositions with high level breathability. To increase the adhesion of the composition with the treated surface, a reinforced mesh is additionally used.
Price, USD/cub. m	35-50	55-60

It is difficult to give an unambiguous answer to the question of which material is the best - foam concrete or aerated concrete. Each of the materials has its own distinctive advantages and disadvantages. Based on the presented table, a brief conclusion can be drawn: gas blocks have higher rates of frost resistance and strength, and foam blocks - thermal conductivity and environmental friendliness. Which technical parameter is more important depends on the scope and characteristics of the application of the building material.

Products made of cellular concrete have long established themselves in the market, firmly occupying the niche of wall masonry materials. Although the first years of the popularity of these materials on the market even experts predicted a great future for them with the complete displacement of bricks, but this did not happen.

The strength indicators of building stone and brick have remained an impregnable bastion for the characteristics of cellular concrete. However, aerated concrete and foam concrete may be of interest for other qualities. Among them energy saving and light weight. Of course, there are a number of operational nuances that should be guided already when choosing between a gas and foam block.

Description of aerated concrete

Aerated concrete in the form of aerated concrete is blocks, slabs or panels intended for the construction of walls, partitions or structures. The basis of the material can be cement, lime, quartz sand, slag and waste from various industries.

A gas generator is introduced into the primary composition, which further activates the process chemical reaction and promotes the formation of a cellular structure.

To understand how aerated concrete differs from foam concrete, it is the manufacturing technique that is of key importance. High-quality aerated concrete cannot be produced in an artisanal way. This is especially true for autoclave blocks, for the manufacture of which special chambers are used. Actually, this is the final stage of production, during which the aerated concrete hardens.

Advantages of aerated concrete

Disadvantages of aerated concrete

The negative qualities of aerated concrete blocks are due to the same porous structure that endowed the material with many of the listed advantages. However, there are not so many shortcomings and only two can be classified as serious:

Where is it best to use?

The best solution in the use of a gas block will be internal walls , partitions, the creation of complex structural elements and the provision of thermal insulation.

It is advisable to use blocks for laying walls, on which it is planned to impose small loads. The panels are suitable as thermal insulation of walls and partitions.

Description of foam concrete

Roughly speaking, the foam block is simplified version of aerated concrete. The material is also one of the most popular representatives of cellular concrete.

In the manufacture of such blocks, approximately the same compositions are used, but the technology of further processing of the mass has significant differences. When deciding whether foam concrete or aerated concrete is better, it should be borne in mind that the first is made using mechanical action. That is, with the help of baroinstallations and a foam generator, bubbles are formed, and later pores. In the case of aerated concrete, a similar effect is created by chemical reaction from a blowing agent.

Pros of foam concrete

Cons of foam concrete

By and large, foam blocks correspond The same negative qualities, as in the case of the gas block. This is, in particular, the ability absorb moisture which negatively affects performance.

Further noted insufficient strength. The question of whether foam concrete or aerated concrete is better in terms of strength is ambiguous. In both cases, this characteristic depends on the brand, but even the most durable products are incomparable with bricks.

In addition, it is the foam block, due to the simple manufacturing technique, that most often offered on the market in unsatisfactory quality which is almost impossible to verify. It is possible to produce foam concrete with minimal technical support, so you should pay attention only to the products of large manufacturers.

Where is the best place to apply?

On the question of whether foam concrete or aerated concrete is better for construction, the first option is more profitable, because. has a wider range of possible applications. Another thing is that aerated concrete allows you to solve problems of a smaller circle but with more responsibility.

The most popular foam concrete in the form of blocks. The construction of walls in low-rise and high-rise buildings using foam blocks is quite common. Indoors, as well as when finishing facades, this material is used as a means of decorative and structurally complex design.

The concrete itself can used for roofing, floor coverings, thermal insulation of communications, pipelines, etc. Grades with high strength rates can also be used in foundations, although such technological solutions yet risky and suitable for structures with small bearing loads.