Aerated concrete floor - features of prefabricated monolithic structures. Aerated concrete floor slabs What is important to consider when using aerated concrete structures

By material plate manufacturing s are divided into:

• reinforced concrete;
• aerated concrete.

Reinforced concrete hollow core slabs

This is the most popular and affordable type of plates.

Previously, the use of massive reinforced concrete floors was not available in the construction of a private house due to their high cost and heavy weight, requiring the use of special equipment for delivery and lifting. Now there are no such problems, and crane or manipulator have become commonplace in low-rise construction.

Hollow-core reinforced concrete slabs have additional relief in the form of through holes-chambers, and they themselves are made of heavy concrete grades with reinforcement, which provides the necessary rigidity and strength. Such an overlap has a number of undeniable advantages:

• Ease of construction in comparison with a monolithic slab; voids significantly reduce the weight of the product, which means that they can be safely used in aerated concrete buildings up to 3 floors inclusive.
• High strength, which is provided by internal cavities, reinforcement and high-quality concrete. The bearing capacity of plates of this type is from 800 kg/m 2 .
• Simplified installation and the ability to mount on bases of any shape. The size of the slab can be 6 and 9 meters, which significantly expands the possibilities for planning.
• Internal cavities can be used to accommodate communications and wiring.
• Good soundproofing.

Device reinforced concrete floors will require around the perimeter. It can be made monolithic using formwork and reinforcement with a thickness of 10 mm or more. The width of the belt is not less than 150 mm - the distance on which the plate will rest. Due to this, the load on the walls is reduced, local stresses caused by the pressure of the upper floor and the slab itself are eliminated.

Marking

According to the configuration of the cavities, the plates are divided into:

• PC - with round voids, rests on 2 sides;
• PCT - with round cavities, based on 3 sides;
• PKK - with round voids, fits on 4 walls;
• PKT - with round cavities, mounting on 2 end and 1 long side;
• PG - with pear-shaped voids; thickness - 260 mm; support on 2 ends;
• PB - made without formwork, by continuous molding; its thickness is 260 mm, the hole diameter is 159 mm; the product is placed on 2 end sides.

According to the size of the cavities and the thickness of the plate, they are divided into the following types:

solid single layer:

• 1P - plates 120 mm thick.
• 2P - plates 160 mm thick;

multi-hollow:

• 1pc - slabs 220 mm thick with round voids 159 mm in diameter.
• 2pcs - slabs 220 mm thick with round voids 140 mm in diameter.
• PB - slabs with a thickness of 220 mm of bee-formwork molding.

Slabs of types 2P and 2PK are made only from heavy concrete.

Dimensions

The size of the hollow slab is included in its marking.

For example, PC 90.15-8. This is a round-hollow slab 90 decimeters long and 15 dm wide. Permissible load on the ceiling is 8 MPa (800 kgf/m2).

Under the spoiler are given standard sizes plates. To view, click on the heading "Table".

Support depth

It is important not to exceed the maximum support depth. Otherwise, the slab will work as a lever, and under heavy loads, a slight lifting of the wall above the slab is possible. It is not noticeable to the eye, but critical to the structure. Under loads from installed furniture, equipment and erected internal interior partitions possible cracks in the walls from the resulting stresses.

The length of support (the depth of insertion of plates into the walls) should not exceed:

• for brick walls- 160 mm;
• when supporting floor slabs on aerated concrete blocks of class B3.5-B7.5 - 200 mm;
• when resting on a concrete armored belt - 120 mm.

The minimum support length is also normalized. It should not be less than:

• 80 mm - for brick walls;
• 100 mm - for walls made of cellular concrete blocks;
• 65 mm - when resting on dense concrete of class B10 and above.

Installation of overlap from reinforced concrete structures necessarily require the use of a crane or manipulator with a large lifting capacity. The weight of a standard 6-meter slab reaches 2 tons. In addition, installation will require certain skills. So alignment is carried out at the seams on the smooth side of the ceiling, after which the plates are fastened with anchors, and the joints are poured cement mortar. Can be used as a heater mineral wool, Styrofoam.

Aerated concrete slabs

Not only are made of foamed concrete, but also interfloor partitions. This material has good strength, low thermal conductivity, it is easy to process and easy to use. Aerated concrete slab can withstand a load of 300 to 600 kg / m 2, and the maximum weight does not exceed 750 kg. The accuracy with which such a ceiling is made allows installation in a short time and does not require additional preparation for subsequent finishing. These are the lightest floor slabs for aerated concrete walls.

Now on the market you can find two types of such structures:

• They are made of concrete by autoclave injection molding, equipped with special elements of the tongue-and-groove type, which simplifies installation. With this method, the density can correspond to the concrete grade D500. This option is most in demand in low-rise construction.
• Standard panels, reinforced with reinforcing elements, can be used in any monolithic construction. Easily processed, inexpensive, well suited for non-standard solutions.

The maximum size of aerated concrete slabs does not exceed 5980 by 625 mm, and the thickness can be from 150 to 300 mm. Minimum length 2980 mm, pitch 300 mm. Such a variety of sizes and low weight makes it easy and with minimal loss to close the space between floors or any complex shape.

The slab should rest with its edges on the wall of the house by at least 10 cm, so the layout must be made taking into account this size.

The disadvantages of such an overlap follow from the features of cellular concrete , therefore, the choice must be approached carefully and after careful calculations of the bearing load and operating conditions.

• Aerated concrete is a very fragile material, which is practically devoid of elasticity. To avoid cracks in the walls and ceilings, it is necessary to take care of a high-quality monolithic or well-buried foundation, excluding any ground movements.
• This material perfectly absorbs moisture, and this will require additional waterproofing with a special primer in areas such as bathrooms and toilets. Reinforcement in the composition of aerated concrete must be processed in accordance with the requirements of SN 277-80, which guarantees the service life of the floors at least 25 years.
• The bearing capacity of less than 600 kg/m 2 is insufficient to accommodate heavy furniture and equipment and a large number of people. Screed, flooring, underfloor heating systems reduce the already low load capacity.
• Additional reinforced concrete beams will be required, laid through a distance in the width of the slab.

Comparative cost

When constructing interfloor structures, the issue of price plays an important role. If we compare all varieties with each other, we get the following sequence. Reinforced concrete hollow slab will be the cheapest with a cost per square meter at 1200 rubles. In second place will be a monolithic product - 2000 - 2500 rubles per square meter. The cost can vary greatly depending on the thickness and manufacturing technology.

The most expensive floor is a foam concrete slab - from 3,000 rubles per square. The high cost is due to the complex manufacturing technology and the small width of the plate.

Also, the cost of a slab ceiling should include the costs of transportation and lifting, which in some cases may be equal to their cost.

Overlap - horizontal design, which is not only a separating barrier between floors, a residential level and a basement or roof, but also performs transfer and distribution function load taken on bearing walls and other elements, also provides the rigidity of the house.

And if it's about roofing, basement or basement ceilings, then they must be arranged in such a way as to guarantee the preservation of heat.

The device of a monolithic reinforcing belt

For aerated concrete buildings reinforcing belt device is mandatory. Besides what it does load distribution function from the floors themselves, the walls of the upper floor, and the so-called payload: people, interior items, equipment, etc., armored belt compensates for the main disadvantage of aerated concrete associated with its inability to bend.
And despite the fact that aerated concrete withstands compression well, the absence of a reinforcing belt will lead to an uneven load on the load-bearing walls. As a result, cracks appear on the walls, and some blocks may even burst. For the device of a reinforcing or strapping circuit heavy types of concrete are used and fittings corresponding class A III.

One of the ways to construct a reinforcing belt can be as follows:

• first, concrete blocks are installed along the outer edge or you can use silicate brick for this;
• reinforcement is laid between them and the edge of the ceiling, which is necessarily tied up (cell size, on average, 10 × 10 cm);
• corners, external and internal, are reinforced with steel brackets;
• thereafter - reinforcing belt poured with concrete

The main types of floors for houses made of aerated concrete

When building houses from aerated concrete, you can use both monolithic and prefabricated floors. Overlappings can be arranged on wooden and metal beams, using hollow core slabs from heavy concrete or cellular, prefabricated monolithic structures or produced directly on site in the form of a monolithic slab.
Each type of cover has its undeniable advantages and, accordingly, the disadvantages, but given the popularity of the use of aerated concrete in private housing construction, the following three selection criteria come to the fore:

1. The need to use special equipment;
2. The cost of materials and installation;
3. Construction speed.

Selection of floors by strength characteristics and maximum loads, in most cases is not relevant, since all these types provide it at a level sufficient for this category of construction objects, on average, the calculated data are within from 500 to 800 kg load per 1 m² area.

But when choosing, materials are preferred having less weight, while saving strength characteristics, and sufficient service life, commensurate with aerated concrete, and resistance to various external influences: natural or chemical nature.

Ceilings from aerated concrete slabs

The use of material similar in properties and characteristics for floors for houses made of aerated concrete is justified, especially considering that the thermal conductivity of the material is the same. Moreover, having settled on this material, you can choose for a house floor device:

• prefabricated monolithic structures, which, during the installation process, are reinforced by the device of concrete reinforced joints;
• monolithic slabs;
• reinforced concrete slabs for coverings.

Many manufacturers of aerated concrete blocks offer the production of floor slabs according to individual sizes, but on average length is up to 6 m, width- up to 1.5 -1.8 m, and thickness- only 30 cm, and the calculated load per 1 m² is about 600 kg. Aerated concrete floor slabs are manufactured only by autoclave, and their density corresponds to D500.

Often monolithic slabs supplied with tongue and groove joints, which ensures the tightness of their fit to each other, and the installation is carried out in the shortest possible time- in one work shift, a team of 2-4 people can cover an area from 50 to 120 m². The most crucial moment when installing floors in this way is agreeing on the terms of production of plates, their transportation to the site and the crane rental time required for this.

For floors using prefabricated monolithic T-shaped blocks special lightweight reinforced concrete beams are used, the length of which is about 7 m, and the height is only 20 cm. The weight of this design is approximately 120 kg, which allows it to be installed manually.

Beam installation step is 68 cm, which, with a block length of 60 cm, provides it with support on a beam equal to 2 cm on each side. When installing the first row, one side of the floor block is also must be at least 2 cm lean on the load-bearing wall of the building.

Formed connections between blocks, in the form of grooves must be filled with concrete., its class must correspond to B20, and after all the floor blocks are laid, knitted reinforcing mesh and a layer of concrete of 5 cm is laid. Complete setting of concrete occurs after 4 weeks, but it is allowed to partially load the structure after 6-7 days.

Ceilings from reinforced concrete slabs

Traditional hollow slabs floors made of heavy concrete can be used for houses constructed from aerated concrete. Their use is most justified if the formed spans are 4.5-6 meters. But before proceeding with the installation, also a durable monolithic armored belt is required, which will distribute it quite big weight on load-bearing walls.

In terms of cost, this one of the most economical device options overlapping of the building, even taking into account the fact that it is necessary to involve special equipment for their installation, namely a crane. In addition, the delivery of slabs to the construction site is often accompanied by certain difficulties., considering the weight and especially the length of the products. The overlap of this type of slab allows loads of 800 and even a little more per 1 m².

Wooden and metal beams

On wooden beams in aerated concrete houses can arrange not only interfloor ceilings , but also basement, attic or attic. But it is not recommended to use this species when, if the distance between load-bearing walls exceeds 6 m, in this case, a deflection occurs that exceeds 1/300 of the length of the log or beam used as beams. The size of the beam section is determined primarily by its type, the planned loads and the span length.

But it is important to observe the following rule: the distance between the axes of adjacent beams should be within the range of half a meter to a meter.

Supporting a beam on a pre-prepared reinforced belt made of monolithic reinforced concrete should be 12-15 cm. To fix them, special anchor plates with an anti-corrosion coating are used.

But, giving preference to wooden beams, it should be remembered that they must be treated with antipyretic compounds, as well as means directed against the reproduction of insects and various microorganisms. The only thing you should exclude are products made on an oily basis, since they prevent moisture from evaporating and given the moisture absorption of the main building material of the building, it will worsen its strength and performance characteristics.

It is also important to take care of sufficient thermal insulation of such a floor- this will protect against the formation of a dew point right in the beam itself. It is necessary to pay attention to the connection of the wall and the beam, the so-called interface node.

To prevent moisture condensation in this area, all gaps must be sealed, for example, sealants or plaits from polyethylene foam. Full contact should not be allowed along the entire length of the beam with the wall, in this place 5 cm clearance required, which is sealed with insulation, most often it is mineral wool.

Beams, the length of which exceeds 4-4.5 m, due to their deflection deform and break monolithic belt, therefore it is recommended before installing them, to perform a small chamfer at their ends to exclude the manifestation of these negative processes. After the beams are installed, you can proceed to the device of the subfloor and the laying of thermal insulation, and if basement, it is necessary to take care of effective vapor barrier.

Similarly, the installation of metal beams occurs, for which are used:

• I-beams;
• channel;
• pipes with a square section.

Their bearing capacity high enough, they provide permissible loads up to 500-600 kg per 1 m², but must have reliable anti-corrosion treatment. Their installation, as well as wooden beams, does not require the involvement of special equipment and can be performed by a team of 2-3 people.

Monolithic overlap

The device of this type of overlap is also is valid in houses made of aerated concrete and arranged using formwork. In this case, the thickness of the slab can be 10-20 cm. Such a floor has the highest bearing capacity, exceeding 800 kg / 1 m². For such a cover span doesn't matter, as well as the configuration: it can be made both round and semicircular, as well as any other shape.

Concrete can be made directly on the site, but it is recommended to use the factory, with exact observance of all technology of its production. Also, most likely, the services of a concrete pump will be required, since the mixture must be supplied to a certain height.

They are reinforced products with grooves made of cellular concrete with a density of D 500 and a strength of D 2.5, they are made in length from 2.5 to 6 meters and have a weight of 240 kg to 670 kg. The manufacturer can make products to order. Transportation of aerated concrete slabs building object produced in a horizontal position. The plates are supplied with steel crossbars necessary for installation. For unloading and stacking, use mounting straps or special holders, i.e. mounting hangers.

Benefits of using aerated concrete floor slabs

• no need to use mounting brackets
• slab builds three times faster than any other type of slab
• the ceiling immediately after installation is able to take the load, for example, pallets with aerated concrete can be placed on it for laying the walls of the next floor.
• aerated concrete floor slabs have a flat surface from below and from above, which reduces the cost of finishing work.

Installation of aerated concrete floor slabs

Installation of floor slabs is carried out on an armored belt, an adhesive solution is applied to the support zone of the slabs. It is very important to accurately set the first plate, so as not to move or correct the next ones. After installing the next plate, it must be pressed close to the previous one along the entire length.

After mounting the plates, ribbed reinforcement with a diameter of 8 mm is laid in the seams between them and filled with concrete.

Can be extended outside the contour of the building. The maximum projection of the panel outside the wall can be 1.5 meters. This way you can get a balcony.

Non-standard elements, such as supports flight of stairs, are made traditional way i.e. filled with concrete.

To give the necessary rigidity and stability to the laid slabs, as well as to create a solidity of the entire floor, an annular anchor must be mounted around the entire perimeter of the load-bearing walls.

Before installing the ring anchor, the outer formwork should be organized using special sealing blocks laid on the adhesive. The height of the sealing blocks is equal to the height of the aerated concrete slabs.

In the resulting cavity, closer to the outside, a heater is laid, as well as anchor and butt fittings are installed and concrete grades of at least 150 are poured.

In construction, aerated concrete floor slabs are in great demand due to their numerous advantages, excellent technical and performance characteristics. The advantages of the material include:

• environmental friendliness;
• durability, reliability, strength;
• excellent soundproof performance;
• light weight, which greatly facilitates the process of transportation, installation.

Having figured out what aerated concrete floor slabs are, what are the main advantages of the material, it is worth considering the main characteristics. This will allow you to choose the right consumable for specific construction activities.

Hollow-core floor slabs made of aerated concrete can have a length of 2.5 to 6 m, the weight of the product depends on the length, is in the range of 240 - 670 kg.

Important! The price of aerated concrete floor slabs in each individual case is calculated individually based on their size.

Often among developers, the question arises whether it is possible to make floor slabs from aerated concrete to order? In many cases, this is possible, especially if an experienced team of builders is involved in the construction. For construction, you may need.
Transportation must be carried out strictly in a horizontal position with the involvement of special vehicles. It is possible to transport reinforced concrete panels by road and on a railway platform, more details.

What is important to consider when using aerated concrete structures

Autoclaved aerated concrete floor slabs can be used. Of these, two design options are offered:

1. Standard floor slabs made of aerated concrete, which are laid in a reinforced concrete frame. The advantage of using this technology makes it possible to provide the ceiling with the highest thermal insulation characteristics.
2. Plates are used, made at the factory on an individual order, taking into account the size and personal characteristics of the house in which the work is carried out. construction works. Aerated concrete structures have a tongue-and-groove system, the presence of which greatly facilitates the installation process, makes it much faster, less costly.

Important! Regardless of the type of material used, an accurate calculation of the floor slab of an aerated concrete house must be performed with respect to the expected temporary, permanent operational loads.

The advantage of using aerated concrete floor slabs

Let us consider in detail what advantages the plates have:

1. Dimensional accuracy, surface evenness, allows you to perform tasks with the highest quality.
2. The tongue-and-groove system allows you to work with minimal loss of time. To perform the work, it is enough to have only a crane and a team of specialists of three people.
3. A high-quality overlap acquires excellent technical indicators of strength, resistance to high mechanical and operational loads. The main advantage of the building material in environmental safety(completely no smell, harmful fumes), which allows it to be used in the construction of residential structures.
4. Since lightweight aerated concrete floor slabs are used during construction, it is possible to significantly reduce the load on the foundation and load-bearing walls of the structure.

Summing up, we can say the following - provided that the floor slabs in aerated concrete houses are laid taking into account all the requirements, the structure is guaranteed to acquire such important advantages as reliability, quality, durability. Do you need to know about foundation blocks and their selection parameters? Then go to

Today, aerated concrete is a very popular building material, and aerated concrete foam block is used not only for the house, but also for the construction of walls.

Aerated concrete is today the most popular building material, and not only walls are built from it, but also interfloor ceilings are erected.

Aerated concrete slabs are made of lightweight, reinforced with reinforcing mesh, and for ease of installation they have a comb-groove system.

Many manufacturers position aerated concrete floors as a universal building material, that is, suitable for the construction of private residential buildings, as well as for administrative and industrial buildings. But most often, aerated concrete foam blocks are used specifically for residential buildings, both for the device and for flat and gable roofs. As a rule, when using aerated concrete floors, houses are erected no higher than three floors.

Types of aerated concrete slabs

Aerated concrete foam block according to the type of production is divided into two types: autoclave and non-autoclave. How do they differ from each other?

Non-autoclaved aerated concrete in terms of price and quality is much preferable to autoclaved.

1. In the process of operation, ceilings made of cellular aerated concrete of autoclave production immediately after installation begin to “age”, and “raw” only harden with time (this process can take place within 10 years). But this difference is also smoothed out, because almost always there is plastering and finishing as interior spaces, and external walls at home.
2. There is a significant difference in production technology: in the manufacture of autoclave, lime acts as a binder, the material hardens under the influence of pressure and temperature. talking plain language, this process is most similar to ripening yeast dough. A concrete-sand mixture is poured into the prepared form, additional chemicals are introduced and the container is closed. Under the influence of temperature, the process of "raising" the concrete cushion and hardening occurs. In non-autoclaved cellular aerated concrete, cement acts as a binder, and the curing process occurs naturally. Whipped into foam is added to the mixture. chemical substances which form gas bubbles.
3. Another difference is in the structure of these materials. Autoclaved aerated concrete foam block has a very uniform distribution gas bubbles, while in non-autoclaved aerated concrete, the number of bubbles increases closer to the top surface of the slab, as the gas tends to rise during the curing process.

Benefits of using

The advantages of using aerated concrete blocks are that they have exact dimensions, this allows you to lay a perfectly flat ceiling.

1. The aerated concrete foam block has very precise dimensions, up to centimeters. This allows you to lay the most even ceiling and significantly save on finishing works. The only caveat: the walls under the ceiling should also be driven out as evenly as possible. If, nevertheless, there is an unevenness of the walls of the house under the ceiling, the aerated concrete can be easily “sawed” with coarse sandpaper.
2. Installation of overlappings is made easily and quickly. Lightness lies in the ease of installation thanks to the tongue-and-groove system. Also don't need a large number of heavy construction equipment. You will need a crane and a team of three installers: one slinger at the bottom and two people for installation at the top. Slinging is done with soft slings, and laying and screeding is done with a clamp. In a few hours, the first one is ready, on which you can walk and where you can place materials for mounting the next floor of the house.
3. Aerated concrete flooring for a private house has excellent technical indicators: strength (meaning a uniformly distributed load) from 600 kg / sq.m (this indicator depends on the brand of cement); high class of fire resistance; excellent heat and sound insulation. Aerated concrete blocks and ceilings withstand internal humidity of the premises from 60%, and with additional moisture insulation of the outer walls - up to 75%. This material is environmentally friendly, that is, it does not emit harmful substances and fumes, odorless.
4. Ease of use is also an advantage. this material, which will reduce the load on the load-bearing walls of the house.
5. Aerated concrete ceilings can be extended beyond the outer dimensions of the outer walls of the house, that is, it is easy to build balcony bases without thermal bridges. The width of such balconies can reach up to 150 cm.

Disadvantages of installation and operation

1. Foam block is quite expensive compared to others building materials and it's up to you to decide if it's worth it. But, on the other hand, you can easily calculate the savings on finishing work and installation costs.
2. Remember that cellular aerated concrete floors are a porous material, which means high vapor and moisture permeability. Without proper waterproofing, the foam block will absorb moisture from environment like a sponge. So when choosing a plaster, choose one that has good vapor and moisture barrier properties.

Saving Secrets

Transportation of gas blocks occurs in the reverse order, so that the first plate is on top.

Discuss with the supplier the order in which the boards are assembled. Loading should be in reverse order, so that the first plate is on top. Then you do not have to shift anything before installation - there is a time saving.

Synchronize an order for a construction crane with a delivery from a foam block manufacturer. Then you will get the opportunity to install in one day basement at home heating boilers or other equipment and immediately proceed with the installation of ceilings. Thus, you do two serious construction operations with one crane call.