Expanded clay concrete - the main characteristics

Expanded clay concrete is a type of lightweight concrete, the main filler of which is expanded clay.

Obtained by special firing of clay, expanded clay has a porous structure. Thanks to this, concrete blocks are relatively light, but strong enough. They are mainly used for the construction of lightweight structures with a good margin of safety.

The main ingredients of expanded clay concrete: expanded clay (60%), cement (10%), quartz sand (30%). You will also need water to mix the solution. Sometimes plasticizers or special air-entraining additives, such as saponified wood resin, are added.

Fraction of expanded clay concrete usually 5-10 mm. The smaller it is, the higher the strength of the blocks and the greater the weight. Therefore, this material has several classifications, for example, according to strength or thermal conductivity.

But you can make it yourself with your own hands as separate blocks, as well as a monolithic structure.

To do this, all parts of the ingredients of expanded clay concrete must be loaded into the concrete mixer in the following order:

1. water,
2. expanded clay,
3. cement,
4. sand.

Usually the water is 8-10%, but the moisture content of the expanded clay itself should be taken into account. If it was outside or was previously wetted for better adhesion, then less water will be needed than for granules stored in a dry room.

In this case, water is added little by little to the desired consistency. If there is too much of it, the solution will be very liquid. In this case, you need to let it settle a little. The consistency of "raw" expanded clay concrete should be such that it could be taken by hand, and all the granules were covered with cement mortar.

In addition to a concrete mixer, you will need a vibrating machine.

A steel plate must be placed in the molding and filled with the mixture. After the finished block is dried for 2-3 days. But ideally it is necessary to let it rest for about a week. If the blocks are dried outside in the heat, they must be sprayed with water to prevent drying out.

The steel plates are removed from the finished, dried block. They will acquire brand strength only after 30 days with regular moisture. The standard form takes 10-11 liters of the mixture.

The main classification is by purpose.

There are types:

• constructive - used for the construction of bridges, load-bearing structures of buildings, overpasses, etc.;
• structural and thermal insulation - mainly used in the construction of walls;
• heat-insulating - basically go as a heater.

They are also distinguished by application (partition and wall), size and shape.

The latter can be solid (monolithic) and hollow, in which blind and through holes can be present.

Partition and wall blocks of expanded clay concrete differ in size. But both are regulated by GOST 6133-99.

Walls have dimensions:

• 390x190x188 mm,
• 288x288x138 mm,
• 288x138x138 mm,
• 190x190x188 mm,
• 90x190x188 mm.

Full-bodied weight reaches 26 kg. Hollow (slotted) is slightly lighter, about 17 kg.

Partition dimensions:

• 590x90x188 mm,
• 390x90x188 mm,
• 190x90x188 mm.

Its thickness is only 90 mm.Weight ranges from 7 to 14 kg (for hollow and corpulent, respectively).

But almost any manufacturer can supply non-standard sizes of expanded clay blocks on order.

Expanded clay concrete blocks have a number of characteristics, the indicators of which can be strikingly different from each other depending on the type and size of the blocks, as well as the presence of certain additives in them:

1. Strength. The lowest values ​​are for thermal insulation blocks (from 5 to 25 kg / cm2). The highest are for constructive ones (from 100 to 500 kg / cm2). All intermediate indicators (from 25 to 100 kg / cm2) for structural and insulating.
2. Thermal conductivity. In terms of thermal conductivity, expanded clay concrete blocks can be compared to wood. And the less cement in the composition, the lower the thermal conductivity. But even heavy constructive ones are much preferable to brick and ordinary concrete. If hollow blocks are used in the construction of a residential building, then it will be significantly warmer. Usually, its indicator fluctuates 0.14-0.66 W / m * K.
3. Frost resistance. The lower the porosity of the material, the higher its value. So, for structural ones, frost resistance is up to 500 cycles, for structural and heat-insulating ones - 150, for heat-insulating ones - 15-50.
4. Soundproofing. The higher the porosity of expanded clay concrete, the better the sound insulation. For example, blocks 590x90x188 mm in size, folded into a partition, provide sound insulation up to 45-50 dB.
5. Water vapor permeability. Heat-insulating ones have a higher vapor permeability (up to 9 mg / m * h * Pa) compared to constructive ones (3 mg / m * h * Pa).
6. Water absorption. For expanded clay blocks, this value is 5-10% by weight, but can be reduced by adding plasticizers.
7. Shrinkage. Gives the same shrinkage as heavy concrete, namely 0.3-0.5 mm / m.
8. Maximum number of storeys of buildings. It is preferable to use structural and heat-insulating blocks for low-rise buildings. But the structural blocks allow you to build buildings of 10-12 floors.

About the features, characteristics and application of different types of expanded clay blocks, watch the following video from the channel ForumHouseTV. You will learn a lot of interesting things.

Advantages of building houses from expanded clay blocks:

• As material for individual construction expanded clay blocks fit just perfect. They perfectly retain heat, practically do not absorb moisture, which is why they do not freeze, perfectly protect against street noise, are fire resistant. Due to its size, masonry is carried out much faster compared to brick. The only drawback is that the blocks do not always fit together in size.
• The financial side of such construction is also pleasant. First, the material itself is inexpensive. Secondly, it allows you to save on insulation, since it has a low thermal conductivity. Thirdly, due to its light weight, it does not require a solid foundation, which can also be saved on. But expanded clay concrete is used only for the construction of walls. It is not suitable for pouring the base, since it does not have sufficient strength for this.
• And due to the practically insignificant shrinkage in the future, you will not have to spend extra money on renovation work on the interior decoration of the rooms.

Thanks to all these advantages, houses made of expanded clay blocks are very popular in Europe. But in Russia they are in no less demand. This is a great budget option. An analogue can be a house made of foam blocks.

Any construction begins with the development of a house project and drawing up a work plan.

Consider the following nuances:

• Select the type of foundation. If the basement is not provided, then you can stop at the strip foundation. As soon as the foundation gets stronger and shrinks, you can start building the walls.
• They lay blocks of expanded clay concrete in the same way as bricks. But here it is important to keep the same thickness of the solution between the blocks. No drops, gaps and voids. All shortcomings are eliminated as soon as they arise.
• For a comfortable stay in the house, the thickness of the walls should be at least 40 cm. Otherwise, additional thermal insulation will be required. In addition, over time, the structure still loses a little its ability to keep heat at the proper level, which will affect the increase in heating costs. Therefore, additional insulation never hurts, but it is better to place it outside.

Thermal insulation can be improved in the following ways:

• It is possible to make facing of expanded clay concrete blocks, but this method is costly and is rarely used.
• A more affordable option is mineral wool. It is laid in 2 layers, with a layer of waterproofing between them. Foil can be used for vapor-permeable insulation.
• Fiberglass can also be used as insulation (both from the outside and from the inside). But to work with it you will need a respirator and protective gloves.
• If the choice is made in favor of polystyrene, then one should choose with a higher vapor permeability index. But it is important to remember that he is very much loved by mice and other small rodents, and therefore he must be walled up in concrete.

External wall cladding made of expanded clay concrete can be made from:

• bricks,
• use facade plaster,
• thermal panels,
• close with siding.

Watch the following video about the advantages of expanded clay blocks in building a house.

The strength of expanded clay blocks depends on their density, so the price for blocks with a higher density is higher.

The higher the block grade, the higher its density:

• Grades 50-100 M are mainly used for thermal insulation purposes.
• For the construction of buildings, the 150-200 M grade is used.
• Grades above 300 M are already used for the construction of various structures, for example, bridges and highways.

The price of expanded clay blocks varies depending on the size, shape (solid or hollow) and brand. On average, in the regions, 1 wall block costs from 30 to 60 rubles, partition wall - 20-40 rubles.

When calculating the cost of all material, delivery costs must also be taken into account. In addition, all blocks are transported in special pallets. If the container is returnable, then a deposit is taken for it. If not, then the cost of one pallet can range from 100 to 300 rubles.