Floors consist of a load-bearing part, which transfers the load to walls or individual supports, and an enclosing part, which includes floors and ceilings. Based on the material of the load-bearing part, a distinction is made between reinforced concrete floors, wooden and steel beams, as well as reinforced silicate and ceramic ones. The cost of floors and floors in the total cost of the house reaches 20% of its total cost.
The main material for constructing floors in modern construction is reinforced concrete. Reinforced concrete floors are divided into prefabricated and monolithic, concreted in formwork. IN last years Prefabricated and monolithic floors are mainly used.
Floors must meet the requirements of strength, rigidity, fire resistance, durability, sound and heat insulation if they separate heated rooms from unheated ones or from the outside environment. Floors in rooms with wet processes must be watertight, and in rooms with gas emissions - gas-tight.
IN country houses With brick walls they use floors made of reinforced concrete panels with round voids, the length of which varies from 4800 mm to 6980 mm, width from 1000 to 2400 mm, height 220 mm, as well as with flat ones - length 2700-4200 mm with gradation of 300 mm, width 1200, 1500 mm , thickness 120 and 160 mm. The panels are laid (Fig. 1) on a layer of freshly laid masonry mortar 10 mm thick with a seal on supports of at least 120 mm. Through one panel (pitch 2400-3000 mm) they are connected to the walls with anchors with a diameter of 8-10 mm, which are attached to the hinges and inserted into the masonry 250 mm from the end of the panel, ending with a bend at an angle of 90° horizontally at 380 mm.
The seams between the panels are filled cement mortar composition 1: 4 (by volume). The panels are installed using truck cranes.
Such floors have a number of valuable qualities, the main ones being greater strength, durability and fire resistance. When designing structures of precast iron elements concrete floors it is necessary to strive to enlarge them to reduce the number of installation operations and butt connections.
Prefabricated reinforced concrete floors are divided into three main groups: in the form of decking (slabs), large-panel and beam. Ceilings in the form of floorings consist of flat or ribbed elements of the same type, laid closely; connect them by filling the gaps with cement mortar. Such floors consist of a load-bearing reinforced concrete part (usually textured at the bottom), a sound or thermal insulation layer and a floor structure. The supports for the decking are walls and purlins. The most common hollow decks are 160 mm high for spans up to 4 m and 220 mm for spans over 4 m. There are longitudinal voids in the decks round section(Fig. 2, a).
When making decks with vertical voids, concrete consumption is reduced by up to 15% compared to round-hollow ones. Vertical round voids are formed using pipe liners (the liners are welded to the channels). Flooring that can cover entire rooms is called large panels. The absence of joints in floor panels within a room increases their sound insulation and provides more high quality ceiling finishing.
To ensure standard sound insulation properties from airborne noise, single-layer structures of interfloor panel ceilings made of heavy concrete, must have a mass exceeding 300 kgf/sq.m.
When installing separate-type floors, which use the sound-insulating ability of the air gap between the upper and lower panels of the communication floor, as well as when installing layered floors, it is possible to ensure the standard sound-proofing ability with the weight of the floor less than 300 kgf/sq.m.
By design, interfloor large-panel reinforced concrete floors can be with a layered floor, a separate type (with a separate floor, a ceiling or two separate load-bearing panels) and with a layered floor and a separate ceiling (Fig. 3). All these floor structures have a relatively small mass (less than 300 kgf/sq.m.); Standard sound insulation is ensured by a layered floor structure or the presence of a continuous air gap in the thickness of the ceiling.
Floor panels are made solid, hollow (with round voids) and hipped. Carrier single layer panel(Fig. 4, a) is a reinforced concrete slab of constant cross-section with a lower surface ready for painting and a flat upper surface.
Solid single-layer reinforced concrete panels with a thickness of 140 mm cover spans up to 3.6 m. To cover large spans (6-6.6 m), solid single-layer prestressed reinforced concrete panels with a thickness of 14-16 cm or expanded clay-reinforced concrete panels with a thickness of 18 cm are mainly used.
The tent panel (Fig. 4, b) has the form of a slab, framed along the contour with ribs facing down in the form of a cornice. Satisfied interfloor ceilings and from flat reinforced concrete panels 14-16 cm thick.
Prefabricated reinforced concrete interfloor floors (Fig. 5) of the beam type consist of T-profile beams and filling between them. The filler here is a roll of gypsum concrete or lightweight concrete slabs 80 mm thick and 395 mm long, reinforced with wooden slatted or timber frames, and in attic floors- lightweight concrete slabs 90 mm thick and 395 mm long, reinforced with welded steel mesh. The seams between the beams and slabs are filled with cement mortar and rubbed. Attics and basement floors They must be insulated and soundproof between floors. To do this, use expanded clay or sand bedding, layered coatings with elastic gaskets. At the same time, it is desirable that heat and sound insulation is not carried out at the expense of increasing the weight of building structures.
Since the elements of beam floors are relatively light in weight, they are used on buildings equipped with low-capacity cranes (up to 1 t).
When installing reinforced concrete floors in sanitary facilities, the floor structure includes waterproofing layer. To do this, they usually stick on top of decking or panels. bitumen mastic 1-2 layers of roofing material.
Monolithic floors performed on installed formwork. By transferring loads from the floor to load-bearing walls, monolithic floors serve as an additional rigid frame for the building. Their installation requires a certain professional skill and should be carried out according to the project under the guidance of a specialist builder. Making floors on site has its advantages. This does not require special transport or lifting equipment. To lift and move concrete, small-scale mechanization equipment is sufficient. Monolithic floors are based on a Monier slab, in which reinforcement is placed in tension areas, that is, in the lower part of the slab. This is because steel has 15 times more tensile strength than concrete. The reinforcement frame of the slab must be located at a distance of at least 3-5 cm from the formwork walls so that concrete can fill this space. The length of the span covered by monolithic slabs should not exceed 3 m. For pipelines plumbing communications special metal or vinyl sleeves with an internal diameter larger than the pipeline being laid are installed in the ceiling. The gap between the sleeve and the pipeline is minted with tarred tow.
The disadvantages of monolithic floors include the need to install wooden formwork almost over the entire area of the house. However, this does not mean that the formwork needs to be installed all at once. The overlap can be done in separate spans, moving the formwork as the concrete sets.
The load-bearing capacity of monolithic floors is ensured by reinforcement, the diameter of which must be at least 8-12 mm. In this case, intermediate joints of rods along the entire length of the floor are undesirable. Minimum concrete layer with outside the overlap must be at least 2 cm. The span must be concreted in one working cycle.
Reinforced concrete floors are used in cottage and industrial construction, serve as a ceiling for the lower floor and a floor for the upper. 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 slabs, which are mounted one after another, the gaps are filled with mortar, the result is monolithic surface. The length of the produced slabs ranges from 2 to 7.2 m, width from 0.8 to 2 m, height up to 22 cm.
Monolithic reinforced concrete floors are one of the most reliable and versatile. Their advantages include:
Disadvantages of monolithic flooring:
Ready-made ones are often used on construction sites. These ceilings have their advantages:
Factory reinforced concrete slabs common construction material, used for covering. Disadvantages of precast concrete floors:
Depending on the design principles, reinforced concrete floors come in several types:
Pouring a monolithic floor will help reduce the amount of concrete used and reduce the pressure on the foundation and walls. Usually used for arranging industrial buildings when large spans need to be filled.
This monolithic floor includes a slab and beams running along it (can go in one or two directions). There are main beams, which rest on columns, walls, and secondary beams, which rest on the main ones. The slabs rest on secondary beams. The edges of the slab rest on the walls or columns. The width of the slabs is from 1.8 to 2.8 m, this allows you to make slabs minimum thickness(5-8 cm). It should be noted that installing formwork for such a structure is more difficult than when pouring flat slabs, and the ceilings are ribbed and require plasterboard covering. The thickness of the ribbed ceiling is 5-6 cm less than usual. The installation of floors with ribbed monolithic slabs is 2 times more profitable than conventional ones.
Scheme of the caisson floor. When pouring large areas The coffered ceiling is also popular. In such a ceiling, beams are placed in two directions (perpendicular) with a step of up to 1.5 m, and a monolithic concrete slab. The beams must have a height of at least 1/20 of the span, and the slab thickness must be at least 4 cm.
The lightness of a reinforced concrete floor is given by the voids between the ribs, which are formed using plastic void formers that perform the function of a removable or permanent 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-rib, often-beam, or waffle monolithic floors.
Beamless ceilings are made in rooms with large uniform loads and when they want to get smooth ceilings that are convenient for installing overhead transport and wiring communications. These could be multi-storey warehouses, refrigerators, meat processing plants. The beamless ceiling is a flat reinforced concrete continuous panel. It rests on columns or mushroom-shaped capitals. The peculiarity of this design is that the load through the panel is transferred directly to the columns. The grid of columns is made square or rectangular shape in increments of 6 m. At the top, the columns expand, forming capitals. The beamless design has a number of advantages: sanitary indicators are improved, ventilation of the premises is facilitated, the laying of communications is simplified, the area requiring additional finishing is reduced (the ceilings are smooth), the ceiling height is lower than when using ribbed or coffered structures, which allows you to save on building maintenance (heating) , cooling).
For filling monolithic structures it is necessary to prepare the following materials: reinforcement, cement (grade from M-400), crushed stone, sand, apparatus for welding reinforcement, boards for formwork, power tools (for cutting boards, reinforcement). When the material is ready, you can begin assembling the formwork; its bottom can be made of boards 3-4 cm thick, or waterproof plywood 2 cm thick; for the side walls, boards 2-3 cm thick are used. If the panels have cracks, they must be covered with film , this will prevent the solution from leaking.
The first thing to do is lay the bottom panels; transverse beams and supports are used for installation. The distance between the racks (supports) is 1-1.2 m. After this, the side walls are mounted. The formwork must be strong, be positioned strictly horizontally, the bottom can be covered with film or roofing felt, this will make the surface smooth and remove minor unevenness of the boards.
The calculation of 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).
The reinforcement is carried out in two balls, the lower one is installed on plastic stands. A mesh is made from reinforcement with a pitch of 150-200 mm. The reinforcement is attached to the mesh soft wire. The reinforcement is taken whole; if the length is short, then an additional piece is attached with an overlap equal to 40 times the diameter of the rod. The joints are placed in a checkerboard pattern. The meshes at the edges are connected by U-shaped reinforcements. After pouring, the frame should be hidden with a ball of concrete of 2 cm.
Depending on the area of filling, additional reinforcement is carried out. It is done with separate pieces of reinforcement 40-200 cm long. The lower mesh must be reinforced in the opening, the upper one above load-bearing walls. In places where they rest on columns, reinforcement requires separate volumetric reinforcing elements.
To fill the floors, use concrete grade M400 (1 part concrete, 2 parts sand, crushed stone -4, water). Concrete is poured into the formwork, starting in one corner and ending in the opposite. When laying, you need to use a deep vibrator, this will help remove voids from the concrete. The reinforced concrete slab is poured without interruptions, with a thickness of 8-12 cm. After pouring, the surface is leveled with devices similar to mops.
The formwork can be removed 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 slabs can be used after 28 days (after complete drying). To avoid drying out and the appearance of cracks, the concrete must be regularly moistened and watered for the first week after pouring. Sometimes the surface is covered with burlap or film to further retain moisture.
When constructing brick, stone, concrete and slag concrete buildings, reinforced concrete floors are used. This is due to their durability, strength, relative ease of installation, as well as short construction time (if prefabricated reinforced concrete floors are used). Next, we will take a closer look at what their types are, and how you can perform the overlap yourself.
All existing reinforced concrete floors can be divided into two types:
Now let's take a closer look at each type of structure.
Reinforced concrete monolithic floors, unlike prefabricated ones, are poured on site, directly at their location.
They come in several types:
Reinforced concrete prefabricated floors are knitted and welded. The welded frame is made of straight reinforcement, which is connected by electric or gas welding. Making a knitted frame is more difficult. For these purposes, use a special knitting wire with a thickness of no more than 2 mm.
Prefabricated structures are divided into the following groups:
Prefabricated structures include reinforced concrete hollow-core floor panels, which are very popular. They are monolithic reinforced concrete slabs reinforced with a reinforcement cage.
Inside the panels there are cylindrical voids that run along the entire length of the slabs. They can significantly reduce the weight of products and also increase the resistance to fracture deformation of the slabs. These panels come in different lengths and widths.
Now let's look at how to perform a beamless floor. It must be said that it is very rare to make reinforced concrete floor beams with your own hands.
So, to erect the structure you need to prepare the following materials and equipment:
First of all, you need to do the formwork yourself. For the bottom of the slab you can use plywood panels at least 2 cm thick, reinforced with bars, or board panels 4-5 cm thick.
Suitable for side walls regular boards 2-3 cm thick, you can, of course, use plywood, but its price is higher.
The formwork is assembled in the following order:
To fill the slab, you should make the solution in the following proportion:
Filling is performed without interruption, starting from one corner and ending with the opposite. In this case, the solution is compacted using a deep vibrator.
After pouring, the concrete is protected from rapid drying. To do this, cover it with damp burlap and sawdust. For the first 8-10 days, the surface is periodically moistened.
After 2-3 weeks, after the solution has collected about 80 percent of its content, remove it. However, the slabs can only be used after 28 days.
Advice!
After completing the slab, it may need to be machined.
It is most effective to perform procedures with a diamond instrument.
In particular, cutting of reinforced concrete with diamond wheels, grinding with diamond cups or diamond drilling of holes in concrete can be carried out.
It must be said that in some cases it may be necessary not to build a slab from scratch, but to repair reinforced concrete floors. It consists in strengthening the structure additional elements in the form of slabs, beams, shells, etc. The procedure is quite complex, so it must be carried out by specialists.
As we found out, there are many types of concrete floors that are designed for different cases. Therefore, in each individual case, you need to choose the right type of structure. In private construction, you can make reinforced concrete floors with your own hands, using the technology indicated above.
From the video in this article you can get Additional information on this topic.
Monolithic reinforced concrete floors consist of a flat slab supported on walls and a system of beams (ribbed and coffered floors) or on walls and directly on columns (beamless floors).
Ribbed floors are a structure consisting of interconnected slabs and beams. The span of the slab (the distance between the axes of the ribs) is taken from 1.5 to 3.0 m, with a thickness of 60 to 100 mm.
The beams (or ribs) usually point downwards, but if you want to have a smooth ceiling they can be placed at the top.
A coffered floor is obtained by crossing ribs of the same height that are evenly spaced in two directions; it is used for aesthetic reasons in interiors public buildings, and also as a means of lightening the large mass of the slab for large spans.
Beamless floors rest on columns through widened capitals.
The above floors are made at a construction site in specially manufactured formwork.
Recently, instead of monolithic structures, promising structural construction systems of prefabricated monolithic buildings erected in inventory formwork of the “Grazdanstroy” type have been used.
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COLOVER PLAN |
INTER-FLOOR COLORS ON WOODEN BEAMS WITH ROLLING SHIELDS |
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1- clean floor; 2 – lags; 3 – plaster; |
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4 – beam; 5 – cranial bars; 6 – roll shield; 7 – sound insulation (backfill) |
WHEN SEALING INTO EXTERNAL WALLS |
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WHEN OPENED INTO EXTERNAL WALLS |
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WHEN OPENED INTO INNER WALLS |
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1 – sealing with mortar; 2 – two layers of roofing felt on mastic; |
3 – anchor; 4 – nails; 5 – open nest; 6 – overlay 50x6 mm |
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WOODEN BEAMS WITH SKULL BARS |
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CONSTRUCTION OF THE ROLLING SHIELD |
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SUPPORTING THE ENDS OF WOODEN BEAMS WOODEN COVERING IN SANITARY UNITS 1 – ceramic plates; 2 – cement mortar; 3 – waterproofing; 4 – flooring made of tongue and groove bars 50 – 60 mm
INTER-FLOOR COLORS |
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ON WOODEN BEAMS AND ROLLING PLATES FROM HOLLOW LIGHTWEIGHT CONCRETE BLOCKS
1 – clean floor; 2 – lags; 3 – plaster or grout; 4 – roll-up shield; 5 – solution;
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6 – lightweight concrete block |
Rice. 47. |
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INTER-FLOOR COLORS
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FROM WOODEN SHIELDS
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FROM GYPSUM CONCRETE PLATES |
ATTIC COVERS |
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INSTALLATION OF PARTITIONS OF THE 2ND FLOOR
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INTER-Apartment Partition
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WOODEN COVERING IN SANITARY UNITS INTERNAL APARTMENT PARTITION |
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Rice. 48. COLOVER PLAN |
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ON REINFORCED CONCRETE BEAMS WITH LIGHTWEIGHT CONCRETE PLATES 1 – clean floor; |
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2- lags; 3 – plaster or grout; 4 – reinforced concrete beam; 5 – gypsum concrete slab; |
6 – solution |
INTER-FLOOR COLORS |
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SUPPORTING PARTITIONS T-BEAM |
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LIGHTWEIGHT CONCRETE ROLL PLATE |
STONE - INSERTER |
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ANCHORING AND SUPPORTING BEAMSINTERNAL WALLNOTES: OUTER WALLINTERNAL WALL1. Reinforced concrete T-beams (RT) must be of the same section C (INTERNAL WALLh = 220) in length no more than 6000 mm and a multiple of 300 mm; |
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2. Slabs (non-load-bearing) roll - gypsum concrete 395x80 (
1 – clean floor; 2 – lags; 3 – plaster or grout; 4 – roll-up shield; 5 – solution;
) unreinforced; carrier – 395x90 (
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)reinforced (for attic floors);
3. The beams are anchored in 1 – 2 pieces.
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INTER-FLOOR COLORS
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Rice. 49.
1 – clean floor; 2 – lags; 3 – plaster or grout; 4 – roll-up shield; 5 – solution;
IN THE RESIDENTIAL PREMISES
) unreinforced; carrier – 395x90 (
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CERAMIC TILE FLOOR |
(IN SANITARY CENTERS) |
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Rice. 50.
FLOOR (BOARD, PARQUET, LINOLEUM)
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INTER-Apartment Partition CERAMIC TILE COLORS IN Washrooms |
ATTIC COVERS |
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* the components and dimensions of the ceiling above the cold basement are indicated Fig.53. 2 BUILDINGS WITH LONGITUDINAL BEARING WALLS SUPPORT ON A BRICK WALL AND ANCHORING DETAILS |
DECODING OF PLATE MARKINGS: |
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P – plate; K – with round voids; 4;6;8;10 – design load; 4;6;8 and 10 kN/m |
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(without taking into account the own weight of the slab); |
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60.12 – length and width in dm. |
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CONNECTION TO A BRICK WALL (MAIN – WITH SEALING IN THE KADK) |
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1 – wall; 2 – overlap; 3 – steel anchor; 4 – cement-sand mortar; 5 – concrete grade M 200; 6 – reinforced concrete
Rice. 51.
SUPPORTING MULTI-HOLLOW FLOORS PANELS ON WALLS
a, b – external large-block; c – internal large-block; g – external brick; d – internal brick; e - the same with channels
Rice. 52.
COLORS OF LARGE-PANEL BUILDINGS AND THEIR DETAILS
a, b, - installation diagrams of the floor with small (a) and large wall spacing (b); c – joint and fastening of floor panels by welding the hinges together while resting on interior walls; d, e – the same using connecting rods
Rice. 54.
CONTINUOUS REINFORCED CONCRETE FLOORS PANELS FOR LARGE PANEL BUILDINGS
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a, h – lifting loops; e, i – embedded parts for welded panel fastenings; g = reinforcement outlet at the corner of the panel; k = loop for fastening the mounting struts.
Rice. 55.
REINFORCED CONCRETE SOLID FLOORS PLATES FOR RESIDENTIAL BUILDINGS WITH SMALL (2.7÷3.6 m) SPACING BEARING WALLS (SERIES 1.143-2)
Rice. 56.
REINFORCED CONCRETE SOLID FLOORS PLATES FOR RESIDENTIAL BUILDINGS WITH LARGE (≤6.3m) PITCH OF BEARING WALLS (ACCORDING TO SERIES 108)
Rice. 56.
Ribbed Pre-stressed Flooring
FLIGHT 9 M
PRE-STRESSED DECK
TYPE TT-12 (12 M) TT-15 (15 M)
1 – mounting loops; 2 – longitudinal ribs; 3 – transverse ribs
Rice. 58.
REINFORCED CONCRETE RIBBED PLATES OF TT- AND T-SHAPED SECTION FOR WALL SPACE UP TO 15 M (SERIES 1.242-1)
USED IN FLOORS AND ROOFS OF PUBLIC BUILDINGS
Expanded clay concrete ventilated slabs for combined roofs with external drainage
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WITH LONGITUDINAL CHANNELS Ø60; THROUGH 165 (SERIES 1.165-2) |
WITH TRANSVERSE CHANNELS 50x50/2; |
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Expanded clay concrete slabs (SERIES 1.165-7) FOR COMBINED ROOFS WITH INNER DRAINAGE |
PARAPET PLATES |
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Rice. 59.
MONOLITHIC REINFORCED CONCRETE FLOORS
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BEAM |
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CAUSED |
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BEAMLESS |
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Floor panels are a slab that includes the main load-bearing part and enclosing elements (ceiling and/or floor). The main purpose of the floor panel is to transfer the load from the building to other load-bearing elements. We will tell you in more detail about the main features of reinforced concrete floor panels.
Currently, most floor panels are made of reinforced concrete, due to the excellent thermophysical characteristics and reasonable price of production of such panels.
Reinforced concrete floors, depending on the combination of elements, are divided into:
Precast floors can be in the form of a deck, beam or large panel. Floor coverings include several similar parts (supporting structure + soundproofing layer + temperature insulation), which must be joined closely to each other. The joint space that appears between them is filled with a special cement mortar. Such slabs are usually laid on walls, interfloor purlins and floors.
Beam reinforced concrete floors are laid on two adjacent walls (central or outermost from the central one).
Large-panel ceilings are panels that can be used to cover large areas.
Monolithic floors are a type of floor that needs to be laid after preliminary preparatory formwork. Monolithic floors generally bear heavy loads from the upper structural elements buildings, therefore, they are also the rigid frame of the building under construction. Monolithic floors are quite difficult to install, so to carry out this process it is necessary to hire only highly qualified, experienced craftsmen.
Monolithic floors can be laid on spans whose length does not exceed three meters. Sometimes, in order to seal in elements of plumbing communications, to connect monolithic slabs special fastening sleeves are used, which have different diameters with the diameter of the pipeline being laid.
Floor panels can be solid (solid), hollow or tent.
Solid floor panels can be used to cover spans no longer than 3.5 m; if the span is long, it is recommended to use a prestressed reinforced concrete panel.
Tent floor panels are a type of slab that has a special ribbed contour around the perimeter. With the help of such tent panels, ceilings between floors are arranged. The thickness of the tent slabs is 14-16 cm.
Hollow-core floor panels are used in multi-story civil construction because, thanks to special hollow holes, they significantly reduce the weight of the building without losing their physical properties.
