Monolithic slab over metal beams. Do-it-yourself monolithic flooring Device monolithic floor beams

Monolithic beam ceilings are made in formwork from monolithic concrete at the construction site, with mandatory reinforcement.

By design, such floors are:

Ribbed (consisting of main beams (purlins) and auxiliary beams with a monolithic slab;

Caissons in the form of a system of intersecting beams of the same section, monolithically connected to the slab.

Beamless, which are a solid monolithic slab, supported by columns with thickened capitals.

Spans between monolithic beams 3-6m (without beams up to 3m). Thickness 60-100m.

If the main and secondary beams have the same height, then such a floor is called coffered.

Main disadvantage:

Time consuming

Non-industrial (long lead times)

Beamless floors are used for frame buildings with a grid of columns 5 * 5 or 6 * 6 can be monolithic and prefabricated rest on the gimp of the columns.

Figure 3 Monolithic reinforced concrete floors

a - ribbed; b - caisson; в - bezel-less; 1-plate; 2-auxiliary beams; 3-main beams (purlins);

4-columns; 5-cross beams; 6-capital

a) monolithic bezel-less floors

b) prefabricated non-girder covered

Theme: Hardwood floors

Timber floors are used mainly in low-rise buildings and in areas where wood is a local material. This type of overlap is simple in the device and has a relatively low cost. The disadvantages of wooden floors include their insufficient durability, combustibility, the possibility of decay and relatively low strength.

Wooden floors consist of beams, which are the supporting structure, inter-girder filling, floor structure and ceiling finishing layer (Fig. 1).

Beams (Fig. 2) are made mainly in the form of rectangular beams, the dimensions of which are set by calculation. Most often, the height of the beams is 130, 150, 180 and 200 mm, and the thickness is 75 and 100 mm. The distance between the beams (along the axes) is usually taken as 600 ... 1000 mm.

To support the inter-girder filling, the so-called cranial bars with a section of 40 x 50 mm are nailed to the sides. The depth of support of the ends of the beams in the nests stone walls take 180 mm (Fig. 3, a). It is necessary to leave a gap of at least 30 mm between the end of the beam and the masonry, so that there is no contact with the masonry and the evaporation of moisture from the beam is ensured. The ends of the beams are antiseptic with a 3% sodium fluoride solution for a length of 750 mm, and the lateral surfaces of the ends of the beams are pasted over with tar paper in two layers on resin. To increase rigidity and stability, the ends of the floor beams are anchored into the walls. The steel anchor is attached to the beam at one end, and the other end is embedded in the masonry.

When supporting beams on interior walls (Fig. 3.6) the ends are antiseptic and wrapped in two layers of tar paper. It is also recommended to seal the gap between the beams and the nest walls with mortar for fire and sound insulation reasons.

The filling between the beams (see Fig. 1) consists of a shield roll, grease on the top of the roll with a 20 ... 30 mm thick clay-sand mortar and a sound-insulating slag layer. In the attic and basement ceilings, the backfill is thermal insulation and its thickness is determined by a thermal calculation.

The structure of the floor on a wooden floor consists of a plank flooring of planed grooved boards, attached with nails to logs of plates, laid across the beams every 500 ... 700 mm. If the floor is parquet, then the flooring is made of unplaned boards (subfloor). Due to the presence of a lag under the floor, a continuous air gap is created under the entire area of \u200b\u200bthe room, which communicates with the air of the room through the rooms arranged in the corners ventilation grates... This ensures the ventilation of the underground space and the removal of water vapor from it. To reduce the floor height, the floor is often laid directly on the beams. However, the absence of lag impairs the sound insulation of the floor.

The lower surface of the hardwood floor forming the ceiling is upholstered plasterboard sheets or plaster on a layer of shredding. For this, lime-gypsum solution is most often used.

Reinforced concrete floors are used in cottage and industrial construction, serve as a ceiling for the lower floor and a floor for the upper one. There are two types of reinforced concrete floors: monolithic and prefabricated. Monolithic ones are made directly at the construction site, after pouring they represent a single horizontal plane. Prefabricated - assembled from factory plates, which are mounted one after another, the gaps are filled with mortar, the result is a monolithic surface. The length of the produced boards ranges from 2 to 7.2 m, width from 0.8 to 2 m, height up to 22 cm.

Advantages and disadvantages

Monolithic reinforced concrete floors are one of the most reliable and versatile. Their advantages include:

High bearing capacity.
Long service life. In the first 50 years, concrete is only gaining strength, such panels can serve several generations of people.
The ability to fill floors of any size and shape. The only condition for large rooms is that additional supports are required.
Fire safety. The concrete does not burn and does not promote combustion.
Lack of seams and transitions.
The thickness is less than that of the finished boards.

disadvantages monolithic floor:

The complexity of the device. The need to use specialized equipment, which greatly complicates the possibility of independent arrangement.
The heavy weight puts a heavy load on the walls and foundations, which makes it impossible to use in some buildings (wooden houses).
Seasonality of work. At temperatures below 5 ° C, anti-freeze additives must be used, which significantly increases the cost of the process.
Fill continuity. It is not recommended that "old" and "new" concrete meet, as this can lead to cracks.

Often on construction sites they use ready-made. These floors have their own advantages:

Factory precast concrete slabs common construction materialused to overlap.

Comparative cheapness.
Installation speed.
Strength and durability.
Ease of installation. Plates can be laid with a truck crane with the help of several slingers.
Noise isolation. Hollow slabs reduce noise levels.
Reliability. Plates are made in the factory, which guarantees quality.

Disadvantages of precast concrete floors:

The need to attract lifting equipment.
Lower level of rigidity in comparison with a monolithic floor.
The presence of spans between the slabs, which requires additional finishing.

Types

Depending on the principles of the device, reinforced concrete floors are of several types:

ribbed;
caisson;
bezel-less.

Pouring a monolithic floor will help reduce the amount of used concrete, reduce the pressure on the foundation and walls. It is usually used for the arrangement of industrial buildings when it is necessary to fill large spans.

This monolithic slab includes the slab and the beams running along it (they can go in one or two directions). There are main beams, which rest on columns, walls, and secondary ones, which rest on the main ones. The slabs are supported by secondary beams. The slab rests on the walls or columns with its ribs. The width of the slabs is from 1.8 to 2.8 m, which allows making slabs with a minimum thickness (5-8 cm). It should be noted that the installation of formwork for such a structure is more difficult than when pouring flat slabs, and the ceilings are ribbed and require plasterboard sheathing. The thickness of the ribbed slab is 5-6 cm less than the usual one. The device of overlapping with ribbed monolithic slabs is 2 times more profitable than the usual one.

Coffered floor scheme.

When filling large areas, coffered floors are also popular. In such a ceiling, the beams are placed in two directions (perpendicular) with a step of up to 1.5 m, a monolithic concrete slab is located on top. The beams must have a height of at least 1/20 of the span, the thickness of the slab must be from 4 cm.

The lightness of the reinforced concrete floor is given by the voids between the ribs, which are formed with the help of plastic cavity-forming molds, which perform the function of removable or non-removable formwork. The installation of a coffered floor allows you to save up to 55% of material compared to flat slabs. Caissons are also called often-ribbed, frequent-girder, or wafer monolithic ceilings.

Beamless ceilings are made in rooms with large uniform loads and when they want to get smooth ceilings, convenient for mounting suspended vehicles, wiring communications. These can be multi-storey warehouses, refrigerators, meat processing plants. Beamless slab is a flat reinforced concrete continuous panel. It rests on columns or mushroom-shaped capitals. The peculiarity of this design is that the load is transmitted through the panel directly to the columns. The grid of columns is made in a square or rectangular shape with a step of 6 m. At the top, the columns expand to form capitals. A bezel-less design has a number of advantages: improved sanitary indicators, easier ventilation of premises, easier laying of communications, reduced area requiring additional finishing (ceilings are smooth), the ceiling height is lower than when using ribbed or coffered structures, which saves on building maintenance (heating , cooling).

Manufacturing technology

For pouring monolithic structures, it is necessary to prepare the following materials: reinforcement, cement (grade from M-400), crushed stone, sand, an apparatus for welding reinforcement, boards for formwork, an electric tool (for cutting boards, reinforcement). When the material is ready, you can start assembling the formwork, its bottom can be made of boards 3-4 cm thick, or waterproof plywood 2 cm thick, boards 2-3 cm thick are used for the side walls.If boards with slots, they must be covered with a film , this will prevent the solution from leaking out.

The first thing to do is to lay the bottom panels; cross beams and supports are used for installation. The distance between the posts (supports) is 1-1.2 m. After that, the side walls are mounted. The formwork must be strong, be placed strictly horizontally, the bottom can be covered with foil or roofing felt, this will give a smooth surface, remove minor irregularities of the boards.

The calculation of the reinforcement in a reinforced concrete floor must be carried out by a specialist. It is recommended to use reinforcement with a diameter of 8-14 mm (depending on the expected loads).

Reinforcement is carried out in two balls, the lower one is installed on plastic supports. A mesh is made of reinforcement with a step of 150-200 mm. The reinforcement is attached to the mesh with soft wire. The reinforcement is taken in one piece, if the length is small, then an additional piece is attached with an overlap equal to 40 times the diameter of the rod. The joints are staggered. The grids are connected at the edges with u-shaped reinforcements. After pouring, the frame must be hidden by a ball of concrete from 2 cm.

Additional reinforcement is carried out depending on the pouring area. It is made in separate pieces of reinforcement 40-200 cm long. The lower mesh must be reinforced in the opening, the upper one - above the load-bearing walls. In places where columns are supported, the reinforcement requires separate volumetric reinforcing elements.

To fill the floors, concrete of the M400 brand is used (1 part is concrete, 2 - sand, crushed stone -4, water). The concrete is poured into the formwork, starting in one corner and ending in the opposite. A deep vibrator should be used when laying to help remove voids from the concrete. A reinforced concrete slab is poured without interruptions, 8-12 cm thick. After pouring, the surface is leveled with devices similar to mops.

It is possible to remove the formwork in 2-3 weeks after pouring, then the slab gains 80% of its strength. If the formwork is removed earlier, then the supports are left. The plates can be used after 28 days (after complete drying). To avoid drying out and the appearance of cracks, the first week after pouring the concrete must be regularly moistened, watered with water. Sometimes the surface is covered with burlap or foil for additional moisture retention.

Monolithic reinforced concrete floors are still of limited use due to their high labor intensity. They are used in cases where it is necessary to cover an atypical room with atypical dimensions, as well as in monolithic buildings.

Monolithic ceilings are made with girder (ribbed) and girderless in the form of a smooth slab (Figure 5.4).

Figure 5.4. Constructive schemes of monolithic reinforced concrete floors:

a - ribbed; b - caisson; в - bezelless; 1 - plate; 2 - beams; 3 - columns; 4 - column capital

5.1.4. Overlapping beams

Beam floors are used in low-rise construction (in wooden and stone buildings), in the reconstruction of old buildings by replacing wooden beams with more durable metal or reinforced concrete.

By material, beams are divided into wood, reinforced concrete and metal.

Overlapping on reinforced concrete beams.Overlappings on reinforced concrete beams consist of beams laid on load-bearing walls with a distance in the axes of 600, 800, 1000 mm, inter-girder filling and a floor (Figure 5.5).

The depth of bearing of the ends of the beams on the walls or purlins is taken at least 150 mm. The ends of the beams on the supports are anchored, and the gaps between the beam and the nest walls are sealed with mortar to a depth of 40-60 mm. Inter-girder filling (Fig.5.6) consists of a roll, which is a flooring of lightweight concrete slabs and a sound-insulating (heat-insulating) layer. The seams between the roll elements and the beams are carefully filled with mortar or glassine is laid on top of the roll. Sound insulation is usually made from a layer of slag or sand with a thickness of at least 60 mm. From below, the roll and the beams are rubbed with mortar. This design is used with plank floors on logs. When installing other types of floors, such as cement, requiring a solid gesture

Figure 5.5. Prefabricated reinforced concrete beams and their support details:

a - layout plan of floor beams; b - general form beams; 1 - beam;

2 - steel anchor; 3 - steel structure; 4 - mounting loop; 5 - embedding with concrete

after preparation, the space between the beams is filled with slag, over which a layer of slag concrete with a thickness of at least 40 mm and the floor are laid (Figure 5.6d). More expedient in these cases are rolls of two-hollow lightweight concrete stones - liners, which have sufficient soundproofing properties and require only careful filling of the joints with mortar (Fig.5.6 d).

Overlappings on metal beams.Currently, metal beams are used only in exceptional cases in the repair and reconstruction of buildings.

Steel beams (usually I-beams) are spaced 1-1.5 m apart. The depth of bearing their ends on the walls is 200-250 mm.

Figure 5.6. Prefabricated girder structure

reinforced concrete elements:

a - general view; b - lightweight concrete slab; c - lightweight concrete insert stone; d, e - flooring options with mineral floors; 1 - reinforced concrete beam; 2 - rolling from lightweight concrete slabs; 3 - waterproofing layer; 4 - soundproofing; 5 - soundproofing pad; 6 - lag; 7 - plank floor; 8 - slag; 9 - slag concrete thick

40 mm; 10 - cement floor 20 mm thick; 11 - grouting with mortar

To increase the area of \u200b\u200bpressure on the masonry in order to protect it from crushing, concrete cushions or steel linings are placed under the ends of the beams. The ends of the beams are anchored into the masonry of the walls and, if necessary, are insulated with felt, followed by sealing the gaps around the perimeter of the nest with concrete (Figure 5.7).

Inter-girder filling can be of reinforced concrete prefabricated or monolithic slabs, and in some cases from brick vaults.

Figure 5.7. Floor structure on steel beams:

a - support of the ends of the beams on the walls; b - detail of anchor fastening; c - overlap filled with reinforced concrete monolithic slab; d - the same, with brick vaults;

1 - steel beam; 2 - steel anchor; 3 - concrete pad; 4 - bolt; 5 - filling with cement mortar; 6 - reinforced concrete monolithic slab; 7 - lightweight concrete; 8 - ceramic tiles on a layer of cement mortar; 9 - brick vault; 10 - soundproofing layer; 11 - two layers of roofing paper; 12 - plank floor along the logs; 13 - steel mesh; 14 - plaster with cement mortar

Overlapping on wooden beams.Currently, wooden floors are allowed to be used only in low-rise buildings and only in areas where wood is a local building material. Their advantages are the simplicity of the device and the relatively low cost. Disadvantages - combustibility, the possibility of decay and relatively low strength.

All wooden floor elements are made of coniferous woods (pine, larch, spruce, etc.). Beams are made mainly in the form of rectangular beams, the dimensions of which are set by calculation. (Fig.5.8). The distance between the axes of the beams is taken from 600 to 1000 mm.

To support the inter-girder filling, bars with a cross section of 40 x 50 mm, called cranial bars, are nailed to the lateral sides of the beams (Figure 5.8). The depth of support of the ends of the beams in the slots of the stone walls must be at least 150 mm (Figure 5.9). The ends of the beams are antiseptic with a 3% solution of sodium fluoride or coated with resin (except for the ends), and when embedded in the outer walls, they are additionally wrapped in two layers of tar paper. On the inner walls or girders, two layers of roofing tar paper are laid under the ends of the beams. The gaps between the walls of the nest and the ends of the beams to a depth of 40-60 mm are tightly sealed with mortar. The arrangement of wooden floor beams, as well as their anchoring, are similar to reinforced concrete beam-type floors (Figure 5.1 c).

The filling between the beams (Figure 5.10) consists of a shield board run, grease on the top of the run with a 20-30 mm thick clay-sand mortar and a sound-insulating layer of slag or calcined earth 60 mm thick. The floors are made of planks along logs with metal ventilation grilles in the corners of the premises. The ceilings are plastered with lime-gypsum mortar on rags or hemmed with sheets of dry plaster.

Figure 5.8. Structural solutions for wooden beams:

1 - single squared beam; 2 - a beam composed of two solid wood bars; 3 - glued timber beam; 4 - cranial bar

Figure: 5.9. Details of supporting wooden floor beams on

stone walls:

a - on outer wall; b - to the internal; 1 - external load-bearing wall; 2 - external self-supporting wall; 3 - internal bearing wall; 4 - wooden beam; 5 - thermal insert; 6 - two layers of roofing roofing on tar mastic or antiseptic zone of the beam; 7 - anchor made of strip iron; 8 - crutches or nails

Figure 5.10. Floor structure on wooden beams:

a - with a plank board roll; b - the same, from hollow blocks; c - the same, from lightweight concrete blocks (slabs); d - floors in bathrooms; d - types of rolls; 1 - beams; 2 - roll forward (panel board); 3 - plaster; 4 - clay grease; 5 - backfill; 6 - lag; 7 - soundproofing pad; 8 - plank floor; 9 - hollow lightweight concrete block; 10 - cranial bar; 11 - solution; 12 - gypsum board; 13 - ceramic tile floor; 14 - cement screed 20 mm; 15 - concrete preparation; 16 - two layers of roofing material on the mastic; 17 - plank floor; 18 - plates; 19 - boards; 20 - false ceiling

In this article, we will talk about what are the ways to build a monolithic floor, and you will also learn about the advantages and disadvantages of these methods. The article will tell you about the basic requirements for the thickness and reinforcement of reinforced concrete floor elements.

Reinforced concrete is an almost eternal material. Many are created from it structural elements - beams, walls, lintels. One of the most difficult, at first glance, products is the overlap. However, the complexity of the construction is fully compensated by the operational properties of the finished product.

Advantages of a monolithic floor:

Highest load bearing capacity of known materials.
The most durable material available.
Relatively cheap raw materials (for concrete).
High qualifications of the entire team are not required to perform the work (1-2 leading specialists are enough).
Combined functions: the base of the second floor floor, armored belt, connection of all walls to each other.
Correctly arranged monolithic construction excludes the appearance of deformation defects ("steps", distortions, cracks).

Disadvantages of concrete floors:

Labor intensity of construction. The work is connected with the device of horizontal formwork of high strength and rigidity.
The accompanying material was used, which after concreting may become unusable - plywood, flanging board, racks (wooden).
Heavy construction weight - strong walls and foundation are required.
High thermal conductivity of concrete - all areas open to the outside must be insulated.
Concrete flooring is only possible on stone walls.

Reinforced concrete floors are suitable for permanent structures designed for a long service life, as well as for premises in which significant static and dynamic loads are provided - workshops, hotels, hostels (with partitions made of stone material).

In private construction, monolithic floor slabs are usually arranged along brick walls, since concrete walls are much more difficult to build than brick ones.

Monolithic slab thickness

Because of the large specific gravity concrete (2400 kg / m 3), products from it are heavy. The mass of the product can be reduced by reducing the amount of concrete in the structure, that is, simply making it thinner. In this case, the stiffness is compensated by the reinforcement. Sufficient thickness of reinforced concrete elements:

load-bearing walls - 160 mm
floors - 200 mm
partitions - 100 mm

The thickness of these elements will be considered sufficient only if the rules of reinforcement are observed. Calculations and many years of practice have shown that there is an optimal balance of mass, volume, section and bearing capacity of reinforced concrete elements. Read about it below in the section "Floor reinforcement". Sufficient thickness brick wall - 380 mm (1.5 bricks).

Slab formwork

Like any reinforced concrete element, the floor requires the installation of a form for concrete - formwork. Since the floor has significant dimensions in area and is at a height, the formwork for it looks like a table: a solid plane that fills the space between the load-bearing walls (and columns) on a spatially rigid frame of racks and slopes. There are three types of formwork, but one requirement is invariable for any of them - a reliable foundation.

Inventory formwork

Factory set, which includes:

Racks - screw sliding jacks, up to 4 m long.
Stand hardware - "tripods" at the bottom for the stability of the freestanding jack and "crown" at the top for seating the table beams.
Wooden beams - Factory glued products of I-profile with a height of 200 mm and a length of up to 4.2 m.
Film faced plywood - sheets of plywood 18-24 mm thick, 1220x2440 mm in size, covered with a resistant film, designed to create a floor plane. The coating can withstand up to 40 concreting cycles.

Such a set is professional - high-rise residential buildings are built with inventory formwork. It is reliable, convenient and designed for constant use. The purchase of a set for the device of one floor will not justify itself - all products are steel and are not cheap. The solution is to rent a formwork. The company's specialists will calculate themselves required amount each of the elements for your object.

The undoubted advantages of this approach are the speed of formwork installation and ease of work, as well as the quality of the plane. The disadvantages include the risk of a delay in the lease term.

Homemade formwork

All elements of the "table" for the ceiling can be made independently from wood and some metal parts.

This method is used when the main elements - posts, beam and plane material (plywood or board) are available. This is the main advantage of the method - the use of improvised material. Obvious disadvantages:

Time consuming construction requiring advanced carpenter skills.
Large waste of material - up to 20% will become unusable.
Problematic height adjustment (horizontal installation).

Combined method

Provides for the partial use of elements of inventory formwork and lumber.

In this case, you can use the factory racks with tripods and crowns, and make the beams and formwork flooring from the board. Or rent a laminated plywood, and assemble the "table" frame from an improvised forest. There can be many combinations.

Floor reinforcement

For the device of the reinforcing cage of the hanging reinforced concrete floor with a thickness of 200 mm, a mirror mesh made of reinforcement A3 Ø 16 mm with a cell of 150-180 mm is used. When using concrete prepared on site, we recommend strengthening the frame by using a smaller rod pitch - 150 mm. If the concrete is factory-made, a step of up to 200 mm is allowed. In the places of support and abutment of elements (support on a wall, column, capital), we recommend making reinforcements - add rods.

Floor concreting

There are concreting rules that should be followed unquestioningly so as not to subject the structure to destruction in the future:

Placing concrete in the floor must be done in one go. With prolonged downtime during concreting, the laid concrete can set, and the new one cannot mix with it. As a result, you get a boundary along which a crack can go.
When concreting in a cool period (0 ... + 5 ° C), use special anti-frost additives. Read more about winter concreting in this article.
Be sure to use vibrators - deep or surface vibrators. Concrete without vibration has 40-50% of design strength. You will find more information on concreting in our article.
The slab formwork is dismantled no earlier than 28 days after the concrete is placed.

reinforced concrete slabs, monolithic are also popular among private developers. Their advantages include not only the solidity and durability inherent in the same slabs, but also the ability to overlap rooms of any configuration. At the same time, the disadvantages include a large mass of slabs, requiring a reinforced base and wall materials of increased strength, and the need to assemble the formwork. Therefore, many self-builders, including the craftsmen of our portal, prefer a lightweight version - monolithic floors on a profiled sheet, which will be discussed in the material. Consider:

What is a monolithic slab on a profiled sheet.
Steel-reinforced concrete flooring technology.
The experience of the portal participants in the construction of unsupported monolithic floors on a profiled sheet.

Monolithic slab on a profiled sheet

Initially, the NIIZhB (Research Institute of Concrete and Reinforced Concrete) of the USSR State Construction Committee developed a method for pouring monolithic reinforced concrete floors with steel (SPN) for industrial buildings and structures. The first recommendations for the design of monolithic reinforced concrete floors with SPN were developed in 1987, almost two decades later, STO 0047-2005 appeared, in fact, slightly updated version the first option. However, for those who want to understand the technology and make calculations on their own, without resorting to the services of the pros, our old-timers advise first to study the manual from the Land of the Soviets.

Yury

If you want to figure it out at no extra cost, read the recommendations for designing monolithic reinforced concrete floors with steel profiled decking, NIIZhB, 1987.

The essence of the technique lies in the fact that the corrugated board serves simultaneously as both the external reinforcement of the slab, as well as the finishing layer.

When it comes to production facilities, such exterior decoration more than enough. According to the developers of the service station, lightweight overlappings along the profile have a number of advantages in comparison with a conventional monolithic slab:

Reducing the amount of steel for beams - by 15%.
Reduction of labor costs - by 25-40%.
Reducing the mass of the slab by 30-50%.
Increase the stiffness of the floors (to horizontal loads).
Simplification of the wiring of communications - placement of highways in corrugations.
Lack of wooden formwork - an increase in the speed of work.

The use of steel-reinforced concrete floors in the construction of industrial and private buildings is permissible under the following basic conditions:

slightly aggressive and non-aggressive operating environment;
humidity conditions up to 75%;
room temperature not higher than + 30 вышеС;
used concrete without potassium chloride and other chlorine-containing additives.

That is, the main contraindication to this type of floors is high humidity, due to which they are usually used as interfloor floors and are not used between the basement and the first floor or the basement and the first floor.

al185 Super Moderator FORUMHOUSE

The professional sheet in the basement will rot, who are interested in terms, look for a search. On the protection of the wheel arches, galvanized screws rust in a couple of months.

For pouring slabs, it is allowed to use both heavy and lightweight concrete, but the compressive strength class for heavy concrete on fine-grained aggregate is from B15 (M200), for lightweight concrete on porous aggregate - from B12.5 (M150). The minimum layer of concrete above the profile deck is 30 mm, if a final screed is provided, if without a screed - from 50 mm. The flooring is made of bearing profiled sheets (H), with a corrugation height of 44 mm.

For the reinforcing cage, reinforcing bars of a periodic profile, class A-III, and wire of class Bp are used. If you plan to overlap with a staircase, then reinforcement of the reinforcement cage around the perimeter and the device of the side formwork are necessary. The steel beams of the load-bearing frame are either rolled or composite profiles.

Steel-reinforced concrete floor technology

In the original version, the profiled sheet is laid not only on the walls, but also on the frame made of steel beams (girders), which is the load-bearing one. The number and parameters of beams are calculated individually, based on the dimensions of the span to be covered and the expected loads, on average, the step is from 1.5 to 3 m, but each sheet should have three support points - in the center and along the edges. Single-layer reinforcement - mesh, wire diameter from 3 mm, pitch 200 × 200 mm, protective layer thickness above the mesh not less than 15 mm.

The profiled sheets are laid across the long side of the span, with wide corrugations down, along the length on the overlapping girders, at least one wave, butt-to-end width. The waves are fixed between themselves with rivets or self-tapping screws with a pitch of not more than 500 mm. In order for the profile and purlins to work as one system, the flooring is fastened with rod anchors, which are welded to the beams. Near load-bearing walls, the anchor should pass through each wave, on intermediate beams through one. In addition, the flooring is fixed to the beams using self-tapping screws or dowels.

However, the use of steel beams is not the most attractive option for self-builders, therefore, many of the craftsmen of our portal prefer an alternative option - an unsupported monolithic overlap on a profile sheet.

The experience of the portal participants in the construction of unsupported monolithic floors on a profiled sheet

Winder

The overlap along the profiled sheet can be without I-beams or channels.

Instead of a frame, a bearing profiled sheet with a wave height of 60 mm and a thickness of 0.7 mm is used, and reinforced reinforcement - lower, upper, transverse and mesh. In this case, the profiled sheet is fixed formwork, and the main loads are taken by the reinforced reinforcement cage. The sheets are laid down with a narrow corrugation and, as in the method with beams, are oriented in waves across the long side of the span. It turns out a kind of ribbed monolithic floor, only the ribs are formed not by removable formwork, but by corrugations. Unlike a steel-reinforced concrete slab supported on beams, this slab is not recommended to be poured with lightweight concrete, and the compressive strength class should be increased to B22.5 (M300).

Winder

It is reinforced concrete that holds the load, neither foam concrete nor expanded clay concrete have the necessary strength. Strengthening the reinforcement is useless in this case.

When pouring, be sure to thoroughly vibrate the solution. If necessary, props are placed from below, which are removed after the concrete has gained strength.

One of our craftsmen decided to use the profiled sheet not only as a formwork, but also as an additional power frame.

worodew

I make a monolithic overlap on the H75 profiled sheet, 0.7 mm thick. In order not to lose its bearing capacity, after pouring, I decided to include it in joint work with concrete. I did this: with a perforator (drill 6 mm) in each ridge I punched holes through a meter and inserted pieces of wire 6 mm thick, 10 mm long into them, and instead of stars I put and tied reinforcement on it, plus a mesh on top. Even the stiffness has increased, I compare before and after tying the reinforcement.

Spans of 3.6 and 2.0 m, reinforcement in the wave is 12 mm, on top - a mesh of wire 5 mm thick, with a cell of 100 × 100 mm From the bottom of the wave, I closed it with scraps of aerated block and sealed the cracks polyurethane foam, one cylinder was enough for 70 m². The deck rests only on external walls and on load-bearing wall in the middle. The slab was poured with a concrete pump, the ceiling thickness was 130 mm, the area was 76 m², it took about 7 m³ of mortar (M300). After a few hours, it was possible to cut off the mounds, focusing on the rule, the next day I moistened the plate and sanded it.

The underfloor heating system is usually mounted in a fine screed, but if desired, you can combine a warm floor and a monolithic overlap on a profiled sheet.

Toha71

Is it possible to install TP pipes directly into the poured plate? Will not such an overlap weaken the presence of TP pipes in it? And if it is possible, how much thickness should be added under the 20 pipe? I understand that the TP should be placed between the layers of reinforcement so that the top layer of reinforcement in concrete is not "drowned" for its normal operation? I would like to try once and pour the concrete evenly, so that only the finishing self-leveling floor remains and does not have to load the slab with an additional screed.

The method has the right to life, subject to an increase in the thickness of the overlap and the presence of a certain experience.