Reinforced concrete slabs are one of the most common types of floors. They provide high strength and allow the assembly of a rigid structure in the shortest possible time. Installation of floor slabs is a demanding task that requires certain knowledge in the field of construction. Everything in order.

Floor slab types

Before starting to mount the horizontal structure, you must select the type. Reinforced concrete prefabricated structures are produced in the form:

• hollow;
• flat (PT);
• hip panels with perimeter ribs;
• with longitudinal ribs.

Most often, the use of reinforced concrete hollow-core... They are available in two types, depending on the manufacturing method:

• hollow-core (PC);
• continuous molding (PB).

Scheme of a hollow-core slab with holes

Hollow core slabs are time-tested products that have been used in construction for several decades. Many regulatory documents and installation rules have been developed for them. Thickness - 220 mm. Products are installed according to serial dimensions, which creates inconvenience for individual construction.

The manufacturing technology of these slabs involves the use of reusable molds for pouring, and before the manufacture of atypical products, you first need to prepare the formwork. Therefore, the cost the right size may increase significantly... Typical PC slabs have a length of 2.7 to 9 meters in 0.3 m increments.

Scheme of reinforced concrete products with dimensions

The width of reinforced concrete products can be:

• 1.0 m;
• 1.2 m;
• 1.5 m;
• 1.8 m.

Structures with a width of 1.8 m are extremely rarely purchased, since, due to the large weight, the process of installation in the design position is greatly complicated.

PB are used in much the same way as the previous type. But the technology of their manufacture allows you to give the product any length. Thickness - 220 mm. The width is the same as the PC series. The disadvantage is the little experience of use and the lack of processing of regulatory documents.

Flat PTs are often purchased as additional elements for hollow-core slabs. They are available in 80 or 120 mm thicknesses and are smaller for overlapping narrow corridors, pantries, bathrooms.

Supporting the plates

The laying of floor slabs is carried out after the preparation of the project or the scheme on which the products are laid out. The overlap elements must be selected so that they are sufficiently supported on brick wall or expanded clay concrete blocks and laying without gaps in width.

The minimum support for the PB and PC series depends on their length:

• products up to 4 m long - 70 mm;
• products longer than 4 m - 90 mm.

A visual diagram of how to correctly and how incorrectly to carry out the support of floor slabs

Most often, designers and constructors take the optimal value of support on the wall 120 mm. This value guarantees reliability with small deviations during installation.

It will be correct to pre-position the load-bearing walls of the house at such a distance that it is easy to lay the slabs. The distance between the walls is calculated as follows: length of standard slabs minus 240 mm. Series PK and PB must be supported on two short sides without intermediate supports. For example, PK 45.15 has a size of 4.48 m, 24 cm is subtracted from it. It turns out that the distance between the walls should be 4.24 m. In this case, the products will lie with the optimal amount of support.

Minimum wall support for PT series products is 80 cm. Installation of such reinforced concrete slabs possible with support points on all sides.

The support must not interfere with the passage of the ventilation ducts. Optimum carrier thickness inner wall brick - 380 mm. 120 mm on each side goes under reinforced concrete floors, and 140 mm remains in the middle - standard width ventilation duct. In this case, it is necessary to lay as correctly as possible. Displacement of the product to the side ventilation hole will lead to a decrease in its cross section and insufficient ventilation of the premises.

Summarizing what was said:

• series PK and PB up to 4 m are supported on both sides by at least 7 cm;
• series PC and PB more than 4 m - not less than 9 cm;
• PT series - on two, three or four sides at least 8 cm.

Storage of boards

Warehousing schemes different types

After the scheme has been developed and the products are purchased, they need to be located on the building site for convenient installation in the design position. There are rules for storing materials:

• you need to lay the elements under a canopy;
• the storage place should be located in the access zone of the crane;
• lining is provided under the support points.

Failure to comply with the last rule will lead to a split in half. PC, PB and PT products work in such a way that the appearance of intermediate supports or a solid base leads to the appearance of cracks. Laying is performed in the following order:

• laid on the ground wooden blocks or boards under the edges of the slab;
• on the boards with a crane from the machine I shift the overlapping element;
• boards or bars are again placed on the laid plate;
• unload the second plate from the machine;
• repeat points 3 and 4, the maximum storage height is 2.5 m.

Masonry requirements

Calculation scheme for floor slabs

In order to correctly install floor slabs, it is necessary to ensure that special requirements for a brick wall are met:

• evenness of the masonry in the place of laying the floors;
• laying in three rows to overlap reinforcement mesh with a cell of 5 by 5 cm made of wire with a diameter of 3-4 mm;
• top row of masonry with inside should be bonded.

If the slabs are mounted on expanded clay concrete blocks, they are additionally arranged under the floors monolithic belt... Such a design will help to evenly distribute the load from heavy floors on expanded clay concrete blocks with less strength. The construction technology provides for pouring a monolithic tape of concrete 15-20 cm thick onto blocks.

Floor laying

To carry out the work, at least three people are required: one performs slinging, and two install them in the design position. If the installers and the crane operator cannot see each other, when installing the slab, another worker will be needed to give commands to the crane.

Reinforced concrete product laying scheme

Fastening to the crane hook is performed with a four-branch sling, the branches of which are fixed at the corners of the slab. Two people stand on both sides of the support and control its evenness.

When installing a PC, pinching into the wall is carried out in a rigid way, that is, bricks or blocks are laid both above and below the slab. When using overlappings according to the PB series, it is recommended to perform hinged fastening. For this, the plates are not pinched from above. Many builders mount the PB series in the same way as PCs and buildings stand, but it's not worth the risk, because the quality of the installation load-bearing structures human life and health depends.

Another important feature of the use of products from the PB series is that it is forbidden to make technological holes in them.

These punches are needed for conducting heating, water supply and sewerage pipes. Again, many builders neglect this even when building multi-storey buildings. The difficulty is that the behavior of this type of floor under load over time has not been fully understood, since there are no objects built for a long time yet. The ban on punching holes has reasons, but it is rather preventive.

Slab cutting

Sometimes, in order to install a slab, you need to cut it. The technology provides for work with a grinder with a disc on concrete. It is impossible to cut the PC and PT slabs along the length, since they have reinforced reinforcement in the support zones. If you support such a cut slab, then one edge will be weakened, serious cracks will go along it. It is possible to cut PB slabs in length, this is due to the peculiarities of the manufacturing method. A timber or board is laid under the cut site, which will facilitate the work.

The division along the length is performed along the weakened part of the section - the hole. this method is suitable for a PC, but is not recommended for a PB, since the width of the walls between the holes is too small.

After installation, the holes in the areas of support on the walls are poured lightweight concrete or clog mineral wool... This is necessary to provide additional strength in the pinch points in the walls.

What to do if it was not possible to evenly spread the product across the width

Sometimes the dimensions of the room do not correspond to the width of the products, in this case all the gaps are brought together into one. This space is covered with a monolithic section. Reinforcement occurs with curved meshes. In length, they rest on the top of the floor and seem to sag in the middle of the monolithic section. for floors, concrete is used at least B 25.

Technology prefabricated floor on bricks or blocks is simple enough, but requires attention to detail.

What should be the minimum support of the floor slab on a brick wall in order to ensure the reliability and durability of the structure? The question is serious, the stability of the building to loads and the safety of people in it depends on its solution. That is why the depth of application of flat reinforced concrete products to brickwork is regulated by construction regulatory documents(SNiP).

The strength of the entire structure of the house depends on the quality of installation of floor slabs.

About hollow concrete products

It is difficult to understand the issue if you do not know what floor slabs are. These are structural elements capital buildings, made of reinforced concrete, for the construction of floors between floors. Inside, along the entire slab, there are voids of various shapes, more often round.

Products are manufactured according to typical projects- series of drawings, where indicated design features and sizes. The length of the elements is 1.5-12 m. Modern technologies production allows you to cut slabs of the required length with a step of 100 mm. The width of the product is made in 4 types: 1000, 1200, 1500 and 1800 mm.

The standard distributed load for which each element is designed is 800 kg / m 2. The slab can be 16-33 cm thick, depending on the design and length, the most common size is 22 cm.

Floor slabs are practically irreplaceable products. The alternative is either monolithic reinforced concrete. Wood loses to reinforced concrete in terms of bearing capacity, and the construction of a monolithic structure is a complex and expensive process.

What determines the minimum distance for support

The normative documents set the minimum length of support of the end part of the hollow core slab on the brick wall - 9 cm. A similar decision is made by design engineers with justification and calculations. Factors affecting the overlap depth:

The support parameters of the slab depend on the type of future structure.

• the overall size of the span and the length of the reinforced concrete product;
• the value of the distributed and point load on the concrete floor;
• types of loads - static, dynamic;
• thickness load-bearing wall brick;
• type of building - residential, administrative or industrial.

All of these factors must be taken into account in calculating the reliability of the structure. In accordance with the standards, the end of a reinforced concrete hollow core slab is applied to the wall so that the size of the overlap is 9-12 cm, accurate data are obtained by calculation.

If you study the series for which the elements of the floors are produced, then they indicate 2 types of sizes:

1. Modular. This is the theoretical span where the element should be placed.
2. Constructive. This is sheer length ceiling slab from one end to the other.

The question arises - why the size of the support is so small, because the slab can be laid by 20-30 cm, if only the width of the fence allows it. But this will not be a support, but a pinching of a reinforced concrete element, since its end also carries part of the load from the wall built above. In such a situation, both the slab and the load-bearing partition will not work properly, which will lead to slow destruction and cracking of the brickwork.

Conversely, due to too little overlap, the heavy slab, together with the entire load, will begin to act on the edge of the masonry and eventually collapse it.

Therefore, the minimum support of 9 cm is rarely used in practice, usually 10-12 cm is taken.

There is another reason why the edge of the slab should not be too deep inside the enclosing structure. The closer the end of the slab to the outer surface, the more heat is lost in such a structural unit, because concrete conducts heat well. The result is a cold bridge, from which there will be cold floors in the house.

Support assembly design

During the construction of a brick building with floors of flat concrete elements, the masonry in the full thickness of the fence is carried out to the design level of the bottom of the ceiling. Then the brick is laid only from the outside in such a way that a niche is formed where the slab will lie. The process is accompanied by the following:

1. If the depth of support is 12 cm (exactly half a brick), then the niche is made at least 13 cm wide so that the end part of the slab does not rest against brickwork.
2. Before installing the floor, a layer of cement-sand mortar of the same brand that was used during the construction of the masonry is laid on the base.
3. Since the edge zones of the slabs will perceive part of the load from the wall erected above, the voids from the end are tightly sealed with concrete inserts so that the product does not collapse from compression.

//www.youtube.com/watch?v=-Ol8NGMGQGc

As a rule, concrete inserts are provided by manufacturers of reinforced concrete products at the factory. If this has not been done, the voids are necessarily filled concrete mix M200 brand in the conditions of the construction site.

IN end walls Buildings floor slabs lie on external fences not only with their ends, but also with one side part. Here, the bearing depth is not standardized, but for reliability, this unit should be designed in such a way that the load from the brickwork does not fall on the first void of the product. Otherwise, from the compression of the hollow part, its destruction may occur. The shoulder of the support should be minimal, its value depends on the design of the slab.

Comments:

During the construction of a building, such an important issue as the support of floor slabs must be taken into account.

Building codes have special instructions in this regard.

Important structural element

Overlappings - load-bearing elements buildings made of reinforced concrete structures... They receive and distribute the loads from their weight and the people and equipment in the building on the walls and supports. With their help inner space the structure is divided into floors, and the attic and basement are separated.

Overlapping in a building must meet many requirements. They must be strong, tough, have good soundproof characteristics, do not burn and do not leak water.

The material used for the production of floor slabs is reinforced concrete. These are mainly hollow-core structures with voids. different forms: polygonal, oval, round. Most often, elements with round voids are used in construction. They are highly durable, technologically advanced and completely ready for installation. Their bearing capacity is 800 kg / m². They are stacked on load-bearing walls located at a distance of about 9 m from each other. Lean on two sides. They are distinguished by fire resistance, rigidity, long term exploitation. Brick, aerated concrete, foam blocks and reinforced concrete panels are used as the material for the walls on which such overlapping elements will be laid.

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Some calculations

To find the amount of support for the floor slab great importance has a base on which it is planned to be laid. It is imperative to take into account the length and weight of the structure, the thickness of the support wall, the seismological stability of the building. In addition, the load and its nature must be taken into account, whether it will be temporary or permanent. Such calculations should be carried out by specialists. For an individual developer, when drawing up a project and installation, the marking of the manufacturer becomes the main reference point.

When using flat overlapping elements, the span can be calculated as follows: you need to add the thickness of this element and the distance between the two supports. As for the depth of support of the floor slab on the brick base, this value should be equal to the thickness of the structure itself, but not less than 70 mm. To calculate minimum thickness outer wall, which will become the basis for floor slabs, must be taken into account thermal insulation layer and facing material on the end parts of the latter. So, a structure with a thickness of 140 mm must be supported by a base, the thickness of which is at least 300 mm.

Installation of often ribbed structures that have inserts requires a minimum deepening of the floor slabs on the base - 150 mm. During installation, do not allow hollow liners to enter the wall. If the ribs are reinforced with two rods, then it is necessary to bend them after one at the support. If the rib has one bar, then the stirrups will take shear stress.

Reinforced stone structures are analogs of flat ones. therefore minimum value the bearing depths of these elements can be determined in the same way. They must be at least 90 mm thick, they are supported on two sides.

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Individual construction

In specialized literature on construction works the definition of the necessary standards regarding the depth of support of floor slabs is given. This indicator is in the range of 90-120 mm. For a more accurate determination of this value, certain calculations must be made, which take into account the length and weight of the structure, the thickness of the supporting wall and the material from which it is made. The expected load must also be determined.

For example, the use of a slab, the length of which is 6 m, assumes a depth of support on a brick base of at least 100 mm. When using structures made of reinforced concrete or steel, a depth of at least 70-75 mm is permissible, on walls made of foam blocks and aerated concrete - at least 120 mm.

When building a house, any developer faces the question of choice interfloor overlap... The most common are three types of floors - wood, monolithic reinforced concrete and precast reinforced concrete, mounted from flat hollow core slabs. It is about this type of overlap, as the most popular and practical for low-rise construction, that will be discussed in this material. From this about interfloor floors in a private house, you will learn:

• What is the difference between hollow-core floor slabs (PC) from floor slabs made by the method formless molding(PB).
• How to lay floors correctly.
• How to avoid mistakes during installation.
• How to store floor slabs.

How to choose a hollow core slab

At first glance at hollow ceilings it may seem that they differ from each other only in length, thickness and width. But specifications hollow floor slabs are much wider and are detailed in GOST 9561-91.

Hollow floor slab, private house.

Hollow interfloor slabs differ from each other in the way of reinforcement. Moreover, reinforcement (depending on the type of slabs) can be performed using prestressed reinforcement or without prestressed reinforcement. Overlappings with prestressed working reinforcement are more often used.

When choosing floor slabs, you should pay attention to the following important point, as the permissible number of sides on which they can be supported. ... Usually only two short sides can be supported, but some types of slabs can be supported on three and four sides.

• PB. Provides support on both sides;
• 1pc. Thickness - 220 mm. The diameter of the round voids is 159 mm. Supports only two sides;
• 1PCT. Having the same dimensions, it can be supported on three sides;
• 1PCK. Can be supported on four sides.

Also, floor slabs differ in their manufacturing method. Often there is a dispute about which to prefer - PC or PB.

Andrey164 FORUMHOUSE user

It's time to overlap ground floor buildings with floor slabs, but I just can't determine what to choose - PC or PB, PB has a better surface finish than PC, but I heard that PB are used only in monolithic-frame houses and country houses, and the end of such a slab cannot be loaded with a wall.

Sasha1983 FORUMHOUSE user

The main difference between the plates lies in the technology of their manufacture.

PC (with a thickness of 160 to 260 mm and a typical bearing capacity of 800 kg / sq. M.) Is cast in formwork. Panels of the PB brand (with a thickness of 160 mm to 330 mm and a typical bearing capacity of 800 kg / sq.m) are manufactured by the method of non-formwork continuous casting (this allows obtaining a smoother and more even surface than that of PC panels). PB is also called extruder.

PB, due to the prestressing of the compressed and stretched zones (prestressing of the reinforcement is done at any length of the slab), are less susceptible to cracking than PCs. PCs with a length of up to 4.2 meters can be produced without prestressed reinforcement and have a greater free deflection than PB.

At the request of the customer, PB can be cut to individual specified dimensions (from 1.8 to 9 meters, etc.). They can also be cut lengthwise and into separate longitudinal elements, as well as bevel cut at an angle of 30-90 degrees, without losing its bearing capacity. This greatly simplifies the layout of such floor slabs at the construction site and provides a great deal of freedom for the designer, because the dimensions of the building box and load-bearing walls are not tied to standard sizes PC.

When choosing interfloor PC slabs (more than 4.2 meters long), it is important to remember this feature - they are prestressed with special stops at the ends of the slab. If you cut off the end of the PC, then the stop (cut off together with the end of the PC and vertical reinforcement) will not work. Accordingly, the working reinforcement will cling to concrete only with its lateral surface. This will significantly reduce bearing capacity plates.

Despite the higher quality smooth surface, good geometry, lower weight and high bearing capacity, such a moment should be taken into account when choosing a PB. Hollow holes in the PC (depending on the width of the slab, with a diameter of 114 to 203 mm) allow you to easily punch a hole in it for sewer riser, with a diameter of 100 mm. While the size of the hollow hole in the PB is 60 mm. Therefore, to break through through hole in the panel of the PB brand (so as not to damage the fittings), you should check with the manufacturer in advance how this is best done.

Floor slabs for a private house: installation features

PB (unlike PC) do not have mounting loops (or you have to pay extra for their installation), which can complicate their loading, unloading and installation.

It is not recommended to use the "popular" method of installing the PB, when the fastening hooks cling to the end of the hollow hole. In this case, there is a high probability that the hook will tear out of the hole due to the destruction of the end of the plate, or the hook will simply slip off. This will cause the slab to fall. Also, at your own peril and risk, you can apply a method in which scrap is inserted into the hollow holes of the PB (two scrap on one side of the slab) and hooks cling to them.

Installation of PB plates is allowed only with the use of soft rods or a special traverse.

ProgC FORUMHOUSE user

To pull the pull out from under the slab, while laying it, leave a 2 cm gap to the adjacent slab. Then we move the already laid slab with a crowbar to the neighboring one.

Max_im FORUMHOUSE user

Personal experience: I laid the slabs at my construction site using this method. The gap was left 3 cm. The slabs were laid on cement-sand mixture 2 cm thick. The mixture served as a lubricant, and the plates were easily moved with a crowbar to the distance I needed.

Also, when installing floor slabs, it is necessary to observe the calculated values ​​of the minimum support depth of the slab. The following numbers can be used as a guideline:

• brick wall, the minimum bearing depth is 8 cm, the maximum bearing depth is 16 cm;
• reinforced concrete - 7 cm, maximum bearing depth - 12 cm;
• gas and foam concrete blocks- at least 10-12 cm, optimal bearing depth - 15 cm;
• steel structures- 7 cm.

It is not recommended to support the floor slab more than 20 cm, because with an increase in the depth of support, it begins to "work" like a restrained beam. When laying floor panels on walls built from gas and foam concrete blocks, it is necessary to install a reinforced reinforced concrete armored belt, which is described in detail in the article:. Read also our article, which tells in detail,. We wish you to successfully apply the acquired knowledge on your construction sites!

It is recommended to seal the ends of the hollow holes before starting the installation of the slabs. The voids are sealed to prevent water from getting inside the panel. It also increases the strength at the ends of the plates (this is to a greater extent refers to a PC than to a PB) in the case of bearing partitions on them. The voids can be repaired by inserting half a brick into them and covering the gap with a layer of concrete. Typically, voids are sealed to a depth of at least 12-15 cm.

If water does get inside the slabs, it must be removed. To do this, a hole is drilled from the bottom in the panel, in the "void", through which water can flow out. This is especially important if the ceilings have already been laid, and the house went into the winter without a roof. Water in frost can freeze inside the hollow hole (since it has nowhere to flow out) and break the slab.

Sergey Perm FORUMHOUSE user

The slabs laid on the ceiling lay for a whole year. I specially drilled holes in the "voids" with a perforator, a lot of water leaked out. Each channel must be drilled.

Before laying floor slabs, it is necessary to select a crane with the required lifting capacity. It is important to take into account the accessibility of access roads, the maximum possible boom reach at the truck crane and the permissible load weight. And also calculate the ability to lay floor panels not from one point, but from two sides of the house.

zumpf FORUMHOUSE user

The surface on which the floor slab is laid must be flat, free of debris. Before laying the panel "spreads out" cement mix, the so-called mortar "bed", 2 cm thick. This will ensure its reliable adhesion to the walls or armored belt. Also, before installing the panels and before applying the mortar to the wall, you can lay a reinforcing bar with a diameter of 10-12 mm.

This method will allow you to strictly control the verticality of mixing of all slabs during their laying (since the panel will not go down below the bar). The rod will not allow her to completely squeeze out from under him cement mortar and lie down "dry". It is not allowed to place the slabs "steps". Depending on the length of the slabs, the divergence of the ends should not exceed 8-12 mm.

A serious mistake during laying is the overlap of two spans with one slab at once, i.e. it rests on three walls. Because of this, loads that are not provided for by the reinforcement scheme appear in it, and under certain, unfavorable circumstances, it can crack.

If such a layout cannot be avoided, to relieve stress, a cut is made with a grinder on the upper surface of the panels, just above the middle partition (wall).

Another point to focus on is how to block a flight of stairs between floor slabs, if there is nothing to support them. In this case, two channels can be run parallel to the slabs, and one can be placed across, along the edge of the opening, tied reinforcement cage in the form of a grid with a cell of 20 cm and a rod diameter of 8 mm, etc. Place the formwork and pour monolithic area... It is not necessary to tie the channel to the floor slabs. In this case, they rest on two short sides and are not subjected to loads from the support unit of the staircase.

How to properly store floor slabs on the site

Ideally, if the panels were brought to the site, they must be installed immediately. If for some reason this cannot be done, the question arises: how to store them correctly.

For storage of slabs, it is necessary to prepare a firm and level area in advance. You can't just put them on the ground. In this case, the lower slab can lean on the ground, and, due to uneven loading, under the weight of the upper slabs, it will break.

Products should be stacked no more than 8-10 pcs. Moreover, spacers are placed under the bottom row (from a bar of 200x200 mm, etc.), and all subsequent rows are placed through spacers - an inch board 25 mm thick. The gaskets should be located no further than 30-45 cm from the ends of the plates, and they should be placed strictly vertically above each other. This will ensure an even redistribution of the load.

, and read about e. The video reveals everything

Reliability of floor support on load-bearing walls ensures safe, reliable and long-term operation of the entire building. The constructive stability of engineering structures depends on competent execution. Therefore, the support of floor slabs on the walls is regulated by SNiP.

Parameters that determined the amount of support

The depth of the overlap on the walls depends on the following factors:

• purpose and type of buildings - residential, administrative, industrial;
• material and thickness of load-bearing walls;
• the size of the span to be covered;
• dimensions of reinforced concrete structures and their own weight;
• the type of loads acting on the floor (static or dynamic), which of them are permanent and which are temporary;
• values ​​of point and distributed loads;
• seismicity of the construction area.

All the factors listed above are necessarily taken into account when performing calculations of the reliability of the construct. In accordance with the current regulatory documents, the support of the floor slab on the brick wall is taken from 9 to 12 cm, the final size is determined by engineering calculations during the design of the building. With less overlaps, the heavy dead weight of the elements, together with the existing loads, will have a direct effect on the edge of the masonry, which can lead to its gradual destruction.

On the other hand, a larger overlap will already be a kind of pinching of reinforced concrete elements with the transfer of weight from the upper section of the wall to their ends. The result is cracking and slow destruction of the wall masonry. Also, when the ends of the products approach the outer surfaces of the walls, an increase in heat loss in reinforced concrete elements occurs with the formation of cold bridges, leading to the formation of cold floors. The cost of parts is proportional to their length, so excessive pinching will increase the cost of the structure.

The node for supporting the floor slab on a brick wall

When erecting brick buildings with the installation of prefabricated reinforced concrete slabs, the laying is carried out in full thickness to the design bottom of the ceilings. Further, the bricks are laid only on the outside of the walls to form a niche into which the slabs can be laid.

It is important to observe the following conditions in the support nodes:

• the ends should not rest against the brickwork, so for the overlap most often used in practice of 12 cm, the width of the niche is ≥ 13 cm;
• the mortar on which the slabs are laid is of the same brand as the masonry;
• the voids in the channels are sealed from the ends with the help of concrete inserts, which will protect the ends from destruction when squeezed under loads. The production of concrete liners is carried out in factories with delivery upon purchase of slabs; in the absence of liners, the channel voids are filled with B15 concrete directly at the construction site.

On end brick walls, slabs reinforced concrete products lie on one side. In this case, the minimum support of the floor slab on the end walls is not standardized. But in order to avoid the destruction of the product when the hollow channel is squeezed, the installation should be carried out so that the masonry laid out above the overlap does not lie on the extreme void of the structure and the shoulders of the moments acting from the load should be of minimum values.

Requirements for the device of armored belts for floor slabs

In buildings with walls made of blocks made of lightweight concrete (aerated concrete, aerated concrete, aerated concrete, polystyrene concrete), with low strength characteristics, the overlap must necessarily rely on reinforced belts. Armopoyas is arranged around the entire perimeter of the building. The height of the armored belt under the floor slabs is from 20 to 40 cm. The connection of the reinforced belts with the floor details must be mechanically strong, for which anchoring devices or joining with reinforcing bars of a periodic profile using electric welding are used.

A number of the following requirements are imposed on the design:

• belts should fit the entire width of the walls; for external widths ≥ 50 cm, a decrease of ≤ 15 cm is permissible for laying insulation;
• reinforcement made using engineering calculations must provide sufficient mechanical strength for the perception of self-weight loads of reinforced concrete elements and upstream structures;
• concrete ≥ class B15;
• the belt is a kind of cold bridge, therefore, its mandatory insulation is necessary in order to prevent the destruction of aerated concrete blocks from accumulated moisture;
• reliability of adhesion to load-bearing walls.

Supporting floor slabs on aerated concrete blocks load-bearing walls reinforced belts is carried out in compliance with the following standardized values:

• at the ends ≥ 250 mm;
• along the rest of the contour ≥ 40 mm;
• when supported on 2 sides of the span ≤ 4.2 m - ≥ 50 mm;
• the same with a span of ≥ 4.2 m - 70 mm.

Aerated concrete blocks are not able to withstand high loads, the material begins to undergo various deformations. Armopoyas, taking on all the loads, evenly distributes them, thereby ensuring that the structure is not destroyed.

Installation of floor slabs on gas silicate blocks also performed with the obligatory installation of monolithic reinforced concrete belts. The required support values ​​correspond to the values ​​given above for walls made of aerated concrete blocks.

During production installation works the following conditions must be met:

• compliance with the symmetry of the laying of elements in the spans;
• the ends of the plates must be aligned in one line;
• all elements must be located in the same horizontal level (control is carried out using building level), permissible deviation in the plane of the plates ≤ 5 mm;
• mortar thickness under the boards ≤ 20 mm, the mortar must be freshly prepared, without starting the setting process. Additional dilution of the mixture with water is inadmissible.

It is unacceptable to lay rows of bricks or reinforcing meshes instead of an armored belt.