Characteristics of expanded clay concrete blocks for load-bearing walls. Characteristics of expanded clay concrete blocks and state standards. House made of expanded clay concrete: a new trend in modern construction

30.10.2019

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Expanded clay concrete is a material that is made from expanded clay, water and cement. When producing blocks, pressing technology is used on a conveyor, after which the blocks are steamed. Expanded clay, which is part of the blocks, has high strength and at the same time it is light.

Expanded clay concrete blocks have a very good characteristics, perfectly insulate sound, have good resistance to humidity and temperature changes. Thanks to these advantages, this material has firmly established itself in construction market. However, like any other product, it has its drawbacks. Below we will consider the main characteristics of expanded clay concrete, its advantages and disadvantages and features.

Specifications

Expanded clay concrete is lightweight material, in which expanded clay is the filler, and cement mortar is the binder.

The composition of the blocks determines their physical and technical properties:

Block density. This indicator is considered one of the main ones, because the strength of the wall, sound insulation and energy saving ability depend on its value. The density of expanded clay concrete blocks varies depending on the quality of the raw materials from which they are made. Typically this value ranges from 500 to 1800 kg/m. cube If we recalculate this value for load resistance, then this value will be 35-25 kg/sq.cm. The weight of one block can range from 10 to 25 kg. The material is durable and can last up to 60 years.
The thermal conductivity of blocks depends on their density. Depending on the density, the blocks are divided into 2 groups according to their ability to save energy. The first includes blocks weighing from 600 to 1100 kg/m. cube The second group includes blocks with a weight from 1200 to 1800 kg/m. cube
Resistance to frost and fire. GOST provides several levels of frost resistance for blocks: F25, 35, 50, 75. The numbers depend on the number of freezing and thawing times that the blocks can withstand without losing strength. Concerning fire safety, then the blocks have the highest security class. Even when exposed to open fire for 7-10 hours, the blocks will not lose their properties.
The vapor permeability of expanded clay concrete blocks is very good, the material is breathable. Expanded clay concrete allows steam and air to pass through 2 times better than brick it can also absorb excess moisture and release it when the air in the room is dry. Thanks to this ability, a good microclimate is established in houses built from expanded clay concrete.
Marking. When purchasing expanded clay concrete blocks, it is important to know exactly the characteristics of the material. All necessary information can be found on the packaging. The first letter K means that the blocks belong to a group artificial stone. The second letter indicates the purpose of the block (Wall, partition, front or ordinary). Letters numbered 4 and 5 indicate the position of the block (corner, row, for seams). Blocks with a cavity inside are designated by the letters PS. Also on the packaging there is information about strength and frost resistance.

Features of expanded clay concrete blocks

Good thermal conductivity properties. For central Russia the thickness of walls made of such blocks should be about 50 cm. If compared with cellular concrete, this value is inferior to it.
Good load-bearing capacity. You can even build from this material high rise buildings. Blocks are also used in construction internal partitions. But it is worth considering that, compared to cellular concrete, walls made of expanded clay concrete will be thicker and heavier, which means that the cost of building the foundation may increase.
The material is highly durable, due to which there is no fighting during construction.
Constructed walls from expanded clay concrete blocks practically do not shrink.
Good blocks are performed with good form., have a slight difference in size.
Good water absorption rates up to 50% indicate good resistance to precipitation. This indicator will be very useful in the construction of unheated premises. The wall will remain dry and last longer.
By cost of material expanded clay concrete blocks cheaper than brick, but more expensive concrete slabs by 15%

Shape and sizes of blocks

Currently, blocks of various shapes are produced. But for blocks to perform their functions, they must have a lot of empty spaces inside. This form helps improve physical properties walls, increasing energy savings. Blocks usually contain grooves and ridges that serve to fix them together, improve thermal insulation properties seams located vertically.

There are different sizes of blocks, but the most common are blocks with a width of 70,190,390,425 mm, a height of 190 and 240 mm, and a length of 120-450 mm.

There are also U-shaped blocks that are used for laying lintels, similar to those used for laying concrete slabs.

This variety of shapes allows the use of blocks in construction different types walls, partitions.

For high-quality masonry of blocks, it is best to use a solution with small fractions. In this case, its consumption will be low.

Pros and cons of expanded clay concrete blocks

So, the advantages that can be noted in blocks made of expanded clay concrete:

The disadvantages of expanded clay concrete blocks include:

Not resistant to strong impacts.
The material is difficult to saw. It is almost impossible to cut straight - this will leave uneven edges on the block.

When making a purchase, it is best to ask the seller for a certificate confirming the product’s compliance with GOST standards. Otherwise, you can buy a product that contains synthetic additives that reduce its characteristics.

Why are expanded clay concrete blocks not popular in our country?

The answer to this question lies in the nineties. At that time there was a period when building materials were in great demand. And many entrepreneurs sought to make as much profit as possible from the production of building materials.

To make the blocks, the cheapest equipment was purchased in a hurry, and the cheapest raw materials were used to further reduce costs. And the raw material for the production of expanded clay concrete is cement, and if it is of poor quality, then the blocks from it are weak, with a damaged structure.

On this moment in Russia there are several large enterprises that have purchased good equipment in Germany and producing good quality blocks.

So, let’s note the main reasons why expanded clay concrete blocks are not in demand in Russia:

No pressing stage. The block production technology involves good pressing on a conveyor, due to which the final product has a compacted structure, good shape and absolutely standard size. In cheap factories, which are widespread in our country, the blocks are not pressed due to the lack of necessary equipment and, as a result, the products have low quality. Of course, blocks that can crumble in your hands are no longer produced, but you can often find very low quality products.
Variation in block sizes. The dimensions of the blocks can differ significantly from each other by several centimeters; you can often find specimens with very uneven edges. These shortcomings lead to the fact that when laying blocks you have to spend a lot of plaster, which smooths out the defects.
The width of Russian blocks is usually no more than 30 cm. This width is inconvenient, it is not enough. It is more convenient to work with wider specimens, and also when large sizes Less plaster is required.

Expanded clay is used to produce blocks - this is a standard technology.

But not everything is so bad, in Russia you can find quite a lot quality products. In St. Petersburg, Kaluga, Zhukovsky and some other cities there are advanced production facilities that produce high-quality products. In addition, Belarusians also supply us with blocks. Belarusian blocks are considered high quality and inexpensive.

conclusions

So, as can be seen from the article, expanded clay concrete blocks have good technical characteristics. The material is easy to lay, durable, and can compete with blocks made of porous concrete. Both of these materials have good properties, pros and cons.

Expanded clay concrete performs well when used in rooms where there is no heating, for wet areas. It is resistant to temperature changes and moisture, so it is very common in northern countries located near the sea.

When purchasing this material, you should carefully study its labeling and ask the seller for a certificate of conformity to make sure that the blocks are manufactured in accordance with GOST. Otherwise you can purchase defective goods, which will have low strength and will not perform required functions during operation.

You decided to build country house, but do you want to use expanded clay concrete blocks as a material? Then you are probably interested in questions about their cost, size and much more.

Time does not stand still, assortment " classic material originally from the sixties" for last years increased noticeably. This happened due to the fact that manufacturers want to stand out from their competitors.

The main problem when searching for information is that 70% of advertising messages about the sale of expanded clay concrete blocks are published by so-called outbids. Most of them contain unreliable data and distort all information about wall blocks.

To help you understand all aspects of choosing this building material, we have written this article. Today you will learn what expanded clay concrete blocks are. Pros and cons, reviews, projects, sizes and prices - we tried to cover the topic from all sides and hope that the information we collected will be useful to you.

Dimensions and prices of expanded clay concrete blocks

Wall blocks are used for masonry walls, and their key indicator is strength grade, since the main load falls on them. Wall blocks are divided into:

four-slot(from 37 rubles per piece);
full-bodied(from 59 to 66 rubles per piece);
double-hollow(from 40 to 45 rubles per piece);
three-hollow(from 39 to 44 rubles per piece);
multi-slit(from 35 to 57 rubles per piece);
(from 119 to 149 rubles per piece);
end-to-end(from 119 to 270 rubles per piece).

Expanded clay concrete blocks

Purpose vertical voids(or cracks) is to give the material mass, density and thermal conductivity. IN full-bodied Expanded clay block has no voids, so it is much heavier and stronger than its counterparts with through and non-through holes. This type of material is used in the construction especially strong walls all types of buildings (multi-storey garage or house).

Four-slit hollow wall blocks will be a good basis for building a cottage type and any other three-dimensional buildings.

Improvement technological processes, with the help of which it is produced concrete mortar, made it possible to begin the production of a new material. This is expanded clay concrete, its composition differs from conventional materials. Expanded clay concrete is considered lightweight, maintaining the quality characteristics of concrete products. The low thermal conductivity makes it possible to use the composition for arranging walls. To produce expanded clay concrete of different densities, it is necessary to know the proportions of plasticizers, with the help of which elasticity is created, and other ingredients that influence the main indicators.

Expanded clay concrete - what is it

The material is a composite with a porous structure used in construction. When compared with other materials, the composition of expanded clay concrete is different.

Compound

Every specialist knows that to prepare expanded clay concrete the following components will be required:

cement mass;
washed sand;
finely dispersed expanded clay, for the production of which natural raw materials were used;
clean water that does not contain technical impurities.

Waste water with a pH less than 4 is not suitable for the recipe for making expanded clay concrete. The same applies to sea water when a white coating forms on the surface.

In addition to the specified components, it is allowed to use sawdust to prepare dry expanded clay concrete mixture wood material, ash, plasticizer additives.

Precise selection of expanded clay concrete composition is carried out directly on the construction site. Here there are certain recommendations with the help of which effective porous expanded clay concrete is obtained:

elasticity is increased through the use of quartz sand;
In order for the structure to perfectly withstand the effects of moisture, expanded clay gravel must be added to the mortar mass;
M400 cement is a good binder that does not contain plasticizers;
cement improves the characteristics of the block material, but here it is necessary to take into account that the volumetric mass of the mixture may increase;
in case it is planned heat treatment blocks, it is necessary to use an alite cement composition.

Speaking about the size of expanded clay concrete:

It is recommended to add expanded clay of large fractions to a composition with a moderate density. This type of concrete with expanded clay retains heat well;
during construction load-bearing structure use fine-grained expanded clay.

Small expanded clay granules will give the material more weight. To obtain " golden mean", it is recommended to use a mixture of large and small stones.

Characteristics of expanded clay concrete and its brand

The main characteristics include the brand and density of the material. The indicators are complex and depend on the composition of expanded clay concrete and the fractions of the feedstock. Each brand is used for its intended purpose:

M50 - used when pouring partitions in a house or arranging a load-bearing wall;
M75 – load-bearing structures are manufactured in residential and industrial premises. In this case, monolithic technology is used;
M100 - the properties are such that the material is ideal for filling screeds;
M150 – used in the manufacture of blocks;
M200 (v15) - block material and lightweight flooring options are prepared from this composition;
M300 - used in the construction of bridges and roads.

Based on density, the material is divided into three groups:

1. Sandless - gravel, water and cement composition are used for production; sand is not added. The main advantage is reasonable cost. Application in construction - used in the construction of walls, floors and ceilings in low-rise buildings.

2. Porous - blocks are made from M20 solution. Based on strength, there are three subtypes of expanded clay concrete:

thermal insulation – d400 – d700 – used as additional insulation for walls;
body-insulating and structural – from d800 to d1 400, used for insulation or when laying partitions;
wall – d1 400 – d2 000, various engineering structures are made from it.

3. Dense – contains an increased amount cement composition, combining the characteristics of sandless and porous compositions. The price of the material is high; it is rarely used in the construction industry.

There is another option for classifying the composite composition - according to volumetric mass. According to this criterion, expanded clay concrete is divided into three groups:

heavy – strength indicator is 25 MPa, volume weight is 1,200 – 1,400 kg per cubic meter;
light - weight is 800 - 1,000 kg, the composition contains lightweight expanded clay material with a low specific gravity;
especially light - the weight of one cube is from 600 to 1,800 kg, the strength is 7.5 - 40 MPa. As a filler, instead of crushed stone, you can add expanded clay, ash gravel, and slag pumice to concrete.

Production technology

How to make expanded clay concrete with your own hands? To do this, you should follow certain tips:

the preparation of expanded clay concrete is carried out in a concrete mixer;
when mixing, all components are supplied in strict sequence - water, cement composition, sand and only after that - expanded clay;

to increase the compressive strength of expanded clay concrete, it is recommended to use reinforcement;
A mixture where the cement mass completely covers each filler granule is considered to be of high quality;
the time of one batch is no more than seven minutes. If this condition is not met, then the characteristics of expanded clay concrete will not meet the requirements of the certificate of conformity. It is recommended to stop the concrete mixer at the moment when the consistency of the mixture resembles sour cream, without containing lumps.

To check readiness, scoop the mixture with a shovel. A quickly blurred slide indicates low quality material.

Application area

As follows from the reviews, expanded clay concrete is universal material with quite wide scope use. Its main feature is the ability to regulate the mixture taking into account the required density of the finished products:

construction of walls of low-rise buildings. Expanded clay concrete is lightweight concrete, from which panels, blocks, etc. are formed;

filling the screed. Many people ask the question: why do we need expanded clay on the floor? But he is considered good insulation material. It is enough to take two shares of stone, add three – sand, one each – water and cement composition. This ratio will ensure good floor strength and rapid hardening of the concrete material.
production of floor slabs. The injection molding method makes it possible to produce products with low weight, excellent resistance to moisture, a long service life, and the ability to preserve thermal energy. One drawback of the material - high level fragility.

Advantages and disadvantages

First let's deal with positive aspects material:

the ratio of thermal conductivity and strength index is the main advantage of the material. As follows from the passport for expanded clay concrete, in terms of heat retention it is practically not inferior to lightweight aerated concrete, but its strength is much higher;
I have an opportunity self-made material. Expanded clay concrete is a composition that does not require large financial costs at the preparation stage. Is it possible to use expanded clay instead of crushed stone in concrete? In certain situations, yes;
price is another important advantage, no comments are required on this, since it is very acceptable;
thermal conductivity of floors – this material has almost no equal in this regard;
long operational period;
environmental safety of the material;
light weight.

There are still quite a lot of advantages in expanded clay concrete, but there is a need to remind you of its disadvantages. Builders note the following disadvantages:

water permeability. The airiness of expanded clay concrete promotes the active absorption of moisture, which has a destructive effect. This feature limits the use of expanded clay concrete. Simply put, external walls made of expanded clay concrete will lose all their advantages, and there will be complete disadvantages. Here a mandatory condition must be met - the exclusion of water from entering the surface of expanded clay concrete.
the need for additional insulation. Although the material has a good thermal conductivity, in most regions it is not used as an independent insulation material. As a rule, load-bearing walls on the outside require an additional insulating layer;
disadvantages of expanded clay concrete products. They don't have ideal geometric parameters, which makes it impossible to make seams when laying tonic, thereby increasing the likelihood of “cold bridges”. But the minus is corrected if the walls are additionally insulated;
unfair attitude of manufacturers. It has already been noted that the production of expanded clay concrete does not require large financial costs. This is often used by artisanal producers, without caring about the final quality of the product.

Conclusion

Experienced specialists assure that it is allowed to add expanded clay to concrete instead of crushed stone. This reduces the strength of the product, but increases its ability to retain heat. The method for selecting expanded clay concrete in this case has its own peculiarities.

Expanded clay concrete blocks - common construction material, which is made in accordance with GOST 6133–99 from sand, cement and expanded clay (in a ratio of 2/1/3) and is actively used in the construction of low-rise buildings.

High performance and technical characteristics combined with affordable price make expanded clay concrete one of the most popular materials on the construction market.

The use of expanded clay concrete blocks instead of bricks allows you to reduce:

the load of the walls on the foundation is 2 times;
house heating costs 3 times;
labor costs 4 times (due to low weight, large format - one standard block is equal to 6 bricks);
significantly speed up construction time.

Specifications

Standard dimensions expanded clay concrete blocks are 190/390/90 mm and 190/390/188 mm. Manufacturers have the right to change these parameters up or down, but no more permissible deviations specified in the tables of technical regulations:

length: +/- 44 mm;
width: +/- 3 mm;
height: +/- 4 mm;
the maximum deviation of the straightness of the ribs is 6 mm.

The weight of expanded clay concrete blocks depends on the type, dimensions and hollowness can vary from 5 to 26 kg. List of the most common types of blocks indicating weight, brand, dimensions and presence of voids:

Solid block (390/190/188 mm.)

SKTs-1PRP 01/01S - 16.9 kg;
SKTs-1PRP - 26 kg;

Solid block (250/188/120 mm)

SKTs-25R - 9.9 kg;
SKTs-25L - 12.8 kg.

2 hollow block(390/190/188 mm)

SKTs-1R - 14.7 kg;
SKTs-1L - 17.5 kg.

Ordinary smooth block (390x188 mm/196x140 mm):

SKTs-14R 01/01 - 7 kg;
SKTs-14R - 10.9 kg.

Seven slot block (390/190/188 mm.)

SKTs-1RG 01/01 - 12.2 kg.
SKTs-1RG - 16.8 kg.

Partition block (390/90/188 mm.)

SKTs-3R 01/01S - 5.1 kg;
SKTs-3R - 9.7 kg;

Volumetric weight of expanded clay concrete blocks depending on the type

structural - volumetric weight up to 1700 kg/m3;
structural and thermal insulation - volumetric weight 700–1400 kg/m3;
thermal insulation - volumetric weight -150–200 kg/m3.

Strength of expanded clay concrete

According to the tables of GOST 6133–99, depending on the brand, it can vary in the range of 25 - 150 kg/cm². This indicator is marked with the letter M and a digital index, which indicates the maximum permissible pressure on the material in kg/cm². For example: M50. The number 50 means that each cm² of block can withstand a load of 50 kg without destruction.

The thermal conductivity coefficient depends on the type of blocks

structural expanded clay concrete - 0.55 W/(m*K);
structural and thermal insulation expanded clay concrete - 0.22 - 0.45 W/(m*K);
thermal insulating expanded clay concrete - 0.10 - 0.17 W/(m*K).

Frost resistance

constructive - 100 – 400 MP3;
structural and thermal insulation - 20 - 100 MP3;
thermal insulation - 15 - 50 MP3.

Compressive strength

structural and thermal insulation - 35 - 100 kg/cm2;
structural - 100 – 500 kg/cm2;
thermal insulation – 5 – 25 kg/cm2.

Other technical specifications

density: from 400 to 1800 kg/m3;
water absorption - 50%;
vapor permeability - 0.30 - 0.090 mg/m/h/Pa (under normal conditions);
shrinkage - 0%;
fire safety class A1. Expanded clay concrete can withstand impact without destruction open flame at 1000ºC up to 10 hours;
Sound insulation indicators comply with SNiP standards 03/23/2003. Wall blocks provide noise protection from 50 to 62 dB, partition blocks - from 41 to 50 dB;
durability - 50 - 75 years;
high environmental friendliness. The content of radionuclides is essentially within the established standards.

Conclusion: Analyzing the above data, it can be noted that the technical characteristics of expanded clay are very worthy. In terms of its physical and mechanical properties, the material is in no way inferior to brick, and costs significantly less.

M300. This is the most durable brand with increased strength indicators.
M200. Used for blocks and light floors.
M150. Suitable for the production of lightweight blocks and panels.
M100. Great for screeding.
M75, M50. The brand is suitable for the construction of external walls and partitions between rooms.

Density

The strength of a material directly depends on its density. WITH high density(ratio of mass to volume of material) the strength of expanded clay concrete increases.

Varieties of expanded clay concrete have the following density:

For structural – up to 1800 kg/m3;
For thermal insulation and structural – up to 1200 kg/m3;
For thermal insulation - 500 kg/m3.

Porosity

The porosity of a material is another important property of it, which is the ratio of pore volume to volumetric mass. The last indicator depends on the type of filler and its quality.

Based on these parameters, expanded clay concrete can be heavy (up to 1400 kg/m3), light (up to 1000 kg/m3) and especially light (600 kg/m3). We’ll talk about the dimensions of the expanded clay concrete block next.

Block sizes

According to the standards, blocks can be:

wall (188*190*390 mm) and
partition (188*90*390 mm).

Depending on the quality and structure of the block faces, they can be ordinary or front.

The first type is used in the construction of walls with additional external decoration,
the second is for the construction of buildings without subsequent finishing.

Read about the density, specific and volumetric weight of expanded clay concrete per 1 m3 and the strength of expanded clay concrete blocks.

Durability

Acoustic and energy-saving properties depend on the density of the blocks, and the reliability and durability of the walls depend on their strength.

Density, depending on the filler, can be in the range of 500-1800 kg/m3.

Strength indicators vary from 35 to 250 kg/cm2. The weight of the blocks themselves can be between 10-20 kg. The durability of design bureaus reaches 60 years.

Thermal conductivity The coefficient allows you to find out how much a material can retain heat. IN in this case

it directly depends on the density of expanded clay concrete.

Look at the comparison table with the thermal conductivity coefficient of expanded clay concrete.

Resistant to low temperatures and fire

These two indicators directly affect the durability of the material. According to the GOST standard for KB blocks, there are four grades for the frost resistance of expanded clay concrete: F25, 35, 50 and 75. The digital values indicate the number of freezing and thawing cycles that a water-soaked block can withstand without changing its strength. As for fire safety, KB blocks have the most high class (A1). This means that in 7-10 hours laying from of this material

do not collapse under the influence of fire.

Vapor permeability

Having an idea of the characteristics various materials, we can conclude that KB blocks have 2 times better vapor permeability than brick.

Comparative characteristics with other blocks

If you compare the technical characteristics of KB blocks, aerated concrete and foam concrete, you can see that they are similar in many properties. Thus, approximately the same indicators are observed in terms of frost resistance and thermal conductivity.

The significant superiority of KB is noticeable in lower moisture absorption and higher strength.

GOST

According to the GOST standard, the composition of expanded clay concrete should include only high-quality raw materials:

The stones contain white and colored Portland cement, which meets the standards.
The composition of lightweight concrete should include: crushed stone, gravel and sand, ash, slag mixtures and other components that are defined by the standard.
To fill the solution, you can use crushed stone and gravel made from rocks.

KB according to GOST 25820-2000 must be made of aggregates that have fractions of 1 cm (in the case of a hollow block) and 2 cm (for a solid block). To obtain color, you can use pigments of inorganic origin.

The following video will tell you whether the use of expanded clay concrete can be dangerous: