Monolithic reinforced concrete floors. Reinforced concrete floors: features of monolithic, prefabricated products

The main elements of the floor are load-bearing structures, which can be made of beams with liners, decking and panels. In large-panel houses, as a rule, floor panels various designs room size. The nomenclature of the II-03-02 catalog includes prestressed floor panels 22 cm high according to GOST 9561-60 with horizontal oval and vertical voids made of heavy and lightweight concrete. Vertical voids are formed by liners from pipes with a channel welded from below. Until January 1, 1963, the use of panels with round voids is allowed. Floor slabs over 5 m are allowed only prestressed. In the presence of manufacturing equipment, two-layer panels and decks are allowed, manufactured on concreting machines.

Floor panels are accepted in four sizes in width - 80.100, 120, 160 cm and are designed for two standard loads - 600 and 900 kg / m 2 (PO and PTO).

The panels are reinforced with cold-drawn carbon steel wire or low-alloy hot-rolled periodic steel grades 35 GS, 25 G2S, 30KhG2S, mounting loops from St. 3. Panels reinforced with cold drawn wire should be prepared from heavy concrete grade 300; reinforced with steel 35 GS, 25 G2S, 30KhG2S - from heavy concrete grade 200.

Panels should be produced, as a rule, with one butt closed during the molding process.

Table 1. Indicators of floor panels

Panel brand	Size in mm		Weight in kg	Panel brand	Size in mm		Weight in kg
	length	width			length	width
ON 59-16	5860	1590	2280	PV 59-16	5860	1590	2330
PTO 59-16				PTV 59-16
ON 59-12		1190	1710	PV 59-12		1190	1750
PTO 59-12				G1TV 59-12
ON 63-10	6260	990	1530	PV 63-10	6260	990	1550
PTO 63-10				PTV 63-10
ON 59-10	5860		1400	HB 59-10	5860		1450
PTO 59-10				PTV 59-10
ON 47-10	4660	9	1145	PV 47-10	4660		1150
PTO 47-10				PTV 47-10
ON 63-8	6260	790	1180	? At 63-8	6260	790	1240
PTO 63-8				PTV 63-8
ON 47-8	4660		885	? At 47-8	4660		920
PTO 47-8				PTV 47-8

For 3-5-storey houses, the II-03-02 catalog recommends panels such as PO, PTO, PV and PTV - 59-16; 59-12 and 59-10, other types of panels are intended for civil engineering.

Permissible deviations from the design dimensions ± 5 mm in length, + 5-10 mm in width, ± 3 mm in height, ± 2 mm in the protective layer.

For 1-2-storey construction, the catalog provides for the use of:

• flat slabs 318 and 258 cm long, 79 cm wide, reinforced with meshes;
• ribbed slabs 398 cm long, 39.5 cm wide, reinforced with meshes and frames;
• T-beams, reinforced with frames (for filling with gypsum concrete and lightweight concrete rolling slabs).

For 1-2-storey residential construction, the catalog allows the use of products intended for 3-5-storey buildings.

In prefabricated construction, it is also possible to use other rational floor panel designs that reduce the weight of supporting structures, reduce material consumption, cost and labor intensity. The characteristics of some panels are given in table. 2.

There are several ways to build floors:

• Use floor slabs.
• Construction of a monolithic reinforced concrete floor.
• The device is a prefabricated-monolithic version.
• Laying of wooden crates, subsequent flooring of drywall or wooden flooring.

Hollow-core floor slabs have a number of significant advantages over other methods: - Hollow-core floor slabs are manufactured industrially, ensuring compliance with all manufacturing standards and the specified design load; - reinforced concrete floor slabs are installed with minimal labor costs and the highest speed of construction, whether it is the installation of a reinforced concrete slab for a private house or a high-rise building; - reasonable price for hollow core floor slabs, relative to other options. In the construction of prefabricated buildings, wall panels are used, using concrete floor slabs in this case it is possible to increase the speed of the process, while the construction resembles a large constructor. Typical dimensions wall panel ideal for joining reinforced concrete slabs, creating a strong frame.

In the construction of prefabricated buildings, wall panels are used, using concrete floor slabs in this case it is possible to increase the speed of the process, while the construction resembles a large constructor. Typical dimensions of the wall panel are ideal for attaching a reinforced concrete slab, creating a solid frame.

Production of reinforced concrete floor slabs

According to the types of floor slabs, hollow slabs are made in special metal forms (formworks) with different outlines of voids. A pre-prepared reinforcing cage is lowered into the mold, after pouring the concrete mixture, poissons are introduced - special pipes that will determine the hollow shapes of the slabs. It is important which form is used - the price directly depends on this. The most important criterion for selecting a manufacturer is the quality of products, confirmed by the relevant certificates, it is on this basis that manufacturers of floor slabs are selected - Ryazan Concrete Concrete Plant No. 2, Eco Yaroslavl.

Overlappings consist of a bearing part, which transfers the load to walls or individual supports, and an enclosing part, which includes floors and ceilings. According to the material of the bearing part, they distinguish reinforced concrete ceilings, on wooden and steel beams, as well as armosilicate and ceramic. The cost of ceilings and floors in the total cost of the house reaches 20% of its total value.

The main material for floor devices V modern construction is reinforced concrete. Reinforced concrete floors divided into prefabricated And monolithic, concreted in formwork. IN last years used mainly prefabricated And monolithic floors.
Overlappings must meet the requirements of strength, rigidity, fire resistance, durability, sound and heat insulation, if they separate heated rooms from unheated rooms or from the outside environment. Overlappings in rooms with wet processes they must be waterproof, and in rooms with the release of gases - gas-tight.

IN country houses With brick walls apply reinforced concrete floor panels with round voids, the length of which is from 4800 mm to 6980 mm, width from 1000 to 2400 mm, height 220 mm, as well as with flat ones - 2700-4200 mm long with a gradation of 300 mm, 1200, 1500 mm wide, 120 and 160 thick mm . Panels laid (fig. 1) on a layer of freshly laid masonry mortar 10 mm thick with embedding on supports of at least 120 mm. Through one panel(step 2400-3000 mm) are connected to the walls with anchors with a diameter of 8-10 mm, which are attached to the hinges and led into the masonry 250 mm from the end of the panel, ending with a bend at an angle of 90 ° horizontally by 380 mm.

Seams between panels fill with cement mortar composition 1: 4 (by volume). Panel mounting carried out with the help of truck cranes.

Reinforced concrete floors

Such floors have a number of valuable qualities, the main of which are great strength, durability and fire resistance. When designing element structures prefabricated concrete floors it is necessary to strive to consolidate them in order to reduce the number assembly operations and butt joints.

Precast concrete floors subdivided into three main groups: in the form of decking (slabs), large-panel and beam. Overlappings in the form of floorings consist of flat or ribbed elements of the same type, laid close; connect them by filling the gaps with cement mortar. Such floors consist of a bearing reinforced concrete part (usually textured from below), a sound or thermal insulation layer and a floor structure. The supports for the flooring are walls and girders. Most common hollow flooring 160 mm high with spans up to 4 m and 220 mm - with spans over 4 m. The decks have longitudinal voids of circular cross section (Fig. 2, a).

In the manufacture of floorings with vertical voids, the consumption of concrete 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). decking, which can cover entire rooms, are called large panels. No seams in floor panels within the room increases their sound insulation and provides more high quality ceiling finishes.
To ensure standard soundproofing properties from airborne noise, single-layer structures interfloor panel ceilings made of heavy concrete, must have a mass exceeding 300 kgf / sq.m.

At flooring device separate type, in which the soundproofing ability of the air gap between the upper and lower floor panels of the connection is used, as well as when installing layered floors, it is possible to ensure the normative soundproofing 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, separate type (with a separate floor, ceiling or from two separate 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.); normative sound insulation is provided by a layered floor structure or the presence of a continuous air gap in the thickness floors.
floor panels produce solid, hollow (with round voids) and tented. Carrier single-layer panel (Fig. 4, a) is reinforced concrete slab constant cross-section with a lower surface ready for painting and a flat upper surface.

solid single layer reinforced concrete panels 140 mm thick cover spans up to 3.6 m. To cover large spans (6-6.6 m), mainly solid single-layer prestressed concrete panels 14-16 cm thick or expanded clay-reinforced concrete 18 cm thick.

hipped panel(Fig. 4, b) has the form of a slab framed along the contour with ribs facing downwards in the form of a cornice. satisfied interfloor floors and from flat reinforced concrete panels 14-16 cm thick.

Prefabricated reinforced concrete floors(fig. 5) beam type consist of T-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 bar 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. Attic and basement floors be sure to insulate, interfloor soundproof. For this, expanded clay or sand bedding, layered coatings with elastic gaskets are used. At the same time, it is desirable that heat and sound insulation be carried out not due to an increase in the weight of building structures.
Since the elements beam floors have a relatively small weight, they are used in buildings equipped with low-capacity cranes (up to 1 t).
At installation of reinforced concrete floors and in sanitary facilities, a waterproofing layer is included in the floor structure. To do this, 1-2 layers of roofing material are usually glued on bituminous mastic over decking or panels.

Monolithic floors

Monolithic floors perform according to formwork. Transferring loads from the floor to load-bearing walls, monolithic floors serve as an additional rigid frame of the building. Their device requires a certain professional skill and should be carried out according to the project under the guidance of a specialist builder. Manufacturing floors location has its advantages. It does not require special transport and lifting equipment. Small-scale mechanization is enough to lift and move concrete. The basis monolithic floors laid down Monier plate, in which the reinforcement is placed in places of tension, that is, in the lower part of the slab. This is because steel has 15 times the tensile strength of concrete. The reinforcing frame of the slab should be located at a distance of at least 3-5 cm from the formwork walls so that concrete can fill this space. Length of span covered monolithic slabs , should not exceed 3 m. For plumbing pipelines, special metal or vinyl sleeves with an inner 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.

To disadvantages monolithic floors include the need to install wooden formwork over almost the entire area of ​​\u200b\u200bthe house. However, this does not mean that the formwork must be set all at once. overlap can be performed in separate spans, transferring the formwork as the concrete sets.
Load bearing capacity monolithic floors provided with reinforcement, the diameter of which must be at least 8 -12 mm. In this case, intermediate joints of the rods along the entire length of the floor are undesirable. The minimum layer of concrete on the outer side of the ceiling must be at least 2 cm. The span must be concreted in one working cycle.

Comments:

• Reinforced concrete floors - the main panels in the construction business
• What are monolithic panels?

Floor panels are the main part of any building. They include load-bearing elements that load the walls, or individual supporting elements. According to the material of the supporting element, reinforced concrete structures. The price of floors is 20% of the total cost of the building.

The composition of the floor panels contains load-bearing elements that exert a load on the walls.

Reinforced concrete floors - the main panels in the construction business

Currently, potential developers prefer to take panels made of reinforced concrete material. In turn, they are divided into:

1. Prefabricated.
2. Monolithic.

Panels must have characteristics such as strength, rigidity, fire resistance, reliability, and quick installation properties. If a building is being built where high humidity is implied during operation, then the floor panels must be resistant to moisture. In country houses, you can often find the use of these structures made of reinforced concrete panels with the presence of round voids. Basically, their length can reach up to 6800 mm, and their width - up to 2400 mm.

Reinforced concrete structures have a huge number of advantages. They have high strength, long service life, and most importantly, they are fire resistant. When creating a project for the construction of a house or any other building, potential developers try to enlarge them in order to reduce the number of installation actions and butt contacts. Prefabricated type reinforced concrete floors are divided into 3 main classes:

1. In the form of flooring (tiled form).
2. Large-panel.
3. Beam.

Deck-shaped structures have flat or ribbed components of the same type in their composition, which must be mounted tightly. Their connection is carried out by means of a special cement mortar. Consequently, they include load-bearing reinforced concrete parts, which have high rates of thermal insulation and sound insulation.

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Interfloor large-panel reinforced concrete structures

By design feature interfloor large-panel structures made of reinforced concrete may have a layered floor. They are lightweight, soundproofing abilities are carried out using a special layered floor structure or the presence of a continuous air gap in the thickness of the ceiling. The floor panels themselves can be solid, hollow and hipped. The hipped panel is a special type of slab, which is framed along the contour with ribs. The ribs are always directed downward.

Reinforced concrete floors are one of their types and, in comparison with wooden ones, they have such advantages as durability, strength and fireproofness. They can be built with your own hands, using the information provided in this article.

Types of reinforced concrete floors

Reinforced concrete floors can be:

• monolithic, manufactured on site;
• prefabricated, assembled from factory-made elements (plates, panels).

In addition to these traditional types, relatively new ones are currently being built:

• often ribbed (from reinforced concrete beams and hollow blocks);
• ceilings made of lightweight concrete (polystyrene concrete, etc.).

Most of these types can be arranged with your own hands. And how to do this, we will consider in more detail below.

Do-it-yourself monolithic reinforced concrete floors

Monolithic reinforced concrete floors one of the most durable types of floors, but also requiring a lot of time and money.

For its device, it is necessary to build a horizontal removable formwork("decks").

Such formwork can be made of wooden panels (from edged boards 25-35 mm thick) or waterproof plywood with a thickness of at least 20 mm. If formwork boards made of boards have gaps, a waterproofing film must be laid on top of the formwork so that the grout does not leak out

Removable formwork is laid on beams - crossbars, which are supported by vertical support legs. Racks can be telescopic, factory-made or self-made from bars or round timber with a diameter of 8-15 mm.
Removable formwork elements for a monolithic reinforced concrete slab can be made independently or you can use ready-made ones - factory-made. But even using ready-made racks and crossbars, the size of the shields or plywood sheets will have to be adjusted to the size of the room, especially if the ceiling has a complex shape in terms of shape.

The formwork must be installed strictly horizontally, without gaps.
On the horizontal formwork, steel reinforcement in the form of a mesh with cells of 200x200 mm is laid and tied with soft knitting wire.

Rebar frame

fittings it is laid along the formwork so that there is a gap of at least 25 mm between it and the formwork. For this, special standard plastic stands are used or they are made independently from wood, plywood or other.

The diameter of the steel reinforcement that is used for the device of a monolithic reinforced concrete floor depends on the size of the floor and the load that it must bear and can be in the range of 12-20 mm.

Depending on the required strength of a monolithic reinforced concrete floor, there may be one or two rows of reinforcement. The second row of steel reinforcement is laid on supports - "chairs" made of reinforcement, previously installed on the bottom row and secured with a soft knitting wire. The height of the "high chairs" depends on the thickness of the reinforced concrete floor being constructed.

The second row of reinforcement is also laid in the form of a grid with cells of 200x200 mm in such a way that the top of the reinforcement and the top of the concrete pour have a distance of at least 25 mm.

For a strong connection of a monolithic reinforced concrete floor with load-bearing walls, a reinforcing belt of steel reinforcement and clamps is arranged inside the latter, to which the floor reinforcement is attached. The reinforcing belt consists of four guides made of reinforcement with a diameter of 12-20 mm, to which prepared clamps are attached perpendicularly with a knitting wire. The distance between the clamps is 200-400 mm.

Before pouring concrete, it is necessary to install formwork in the form of boxes for technological openings provided for by the building project (smoke or ventilation ducts), lay electrical wiring and set “beacons” to control the thickness of the concrete of the monolithic slab.

Pouring concrete

Concrete for monolithic slabs is ordered ready-made or made independently using one or more concrete mixers. If the ceiling is at a height, then concrete must be supplied using lifting mechanisms.

When laying concrete, it is necessary to ensure that it lays down tightly, evenly covering the reinforcing cage.

Concrete laying work must be organized in such a way as to be carried out as quickly as possible, without interruption for 3 hours. The formwork is removed after the concrete has completely hardened.

IN Lately, in addition to the device method described above, reinforced concrete monolithic flooring is often made on corrugated board.

Prefabricated reinforced concrete floors from slabs and panels

Ceilings from precast concrete slabs and panels can be divided into floors from small-sized and large-sized elements.

In individual construction and construction of low-rise buildings, mainly small-sized reinforced concrete slabs are used, while large-sized ones are used in the construction of multi-storey buildings.

In addition, reinforced concrete slabs differ in the type of cross-section into multi-hollow, ribbed and solid, and in the method of reinforcement into slabs with conventional or prestressed reinforcement.

Ribbed floor slabs are made with ribs in one or two directions with a solid slab in the upper part. Such a plate works well for bending, but due to the protrusions from below, it forms a non-flat ceiling, which limits its use in residential buildings.

Do-it-yourself reinforced concrete floor slab

The manufacture of floor slabs is a rather complicated technological process and it is better to purchase them ready-made, factory-made. But sometimes there may be a need for a small or irregular shaped slab to close a certain space that cannot be covered with standard slabs.

In this case, you can make a solid or hollow reinforced concrete slab with your own hands.

To do this, you first need to make a formwork for the future slab. On a flat horizontal platform, a horizontal formwork made of a wooden shield or waterproof plywood is laid. The dimensions and shape of the horizontal formwork must correspond to the required dimensions and shape of the iron concrete slab.

On the sides of the horizontal formwork, a vertical formwork in the form of a ledge is nailed, the height of which must correspond to the required height of the slab.

Reinforcement in the form of a grid of 20x20 cm is laid on horizontal formwork on stands 25 mm high. In this case, the ends of the reinforcement should not rest against the sides of the formwork, but be separated from them at a distance of 20 mm. The fittings are tied with thin soft steel knitting wire. On the lower row of reinforcement, stands are laid and fastened - "high chairs" for the upper row. The height of the supports is calculated so that there is a distance of at least 25 mm between the upper row of reinforcement and the upper plane of the concrete slab.

The upper row of reinforcement is laid on the "chairs", also in the form of a grid of 20x20 cm, and is attached to them with the same knitting wire.

When the frame of the slab is ready, the entire structure is poured with concrete with careful laying. If it is possible to use vibrators when laying, this is best option. If not, it is necessary to pour and disperse the concrete very carefully throughout the entire volume of the structure so that no voids remain. As already mentioned, the height of the concrete layer above the upper row of reinforcement must also be at least 25 mm.

After the concrete is poured, the surface of the slab is leveled with a mop-shaped device that you can make yourself.

The manufactured slab, after the concrete has set, must be cured for at least two weeks. At the same time, it is desirable to constantly moisten its surface with water to give greater strength.

Often ribbed reinforced concrete floor

Frequently ribbed reinforced concrete slab is a beam type slab, as load-bearing structure in which reinforced concrete beams are used, and hollow ribbed blocks are used as inter-beam filling.

When constructing such a reinforced concrete floor, reinforced concrete beams are first installed. For reliable connection of beams with load-bearing walls, belts of steel reinforcement 23-28 cm high are arranged in the latter. The ends of the beams should go into the belt passing through the load-bearing walls by 8 - 12 cm.

The step of reinforced concrete floor beams is 40-60 cm and depends on the size of the hollow blocks that rest on the beams and fill the space between the beams.
The height of the hollow blocks determines the height of the often ribbed reinforced concrete floor and is usually between 16 and 27 cm.

The soundproofing characteristics of this type of flooring depend on the type of hollow blocks.

In the places of the design location of the interior partitions, under them, in the ceiling, a reinforcement of two beams is installed, which are laid side by side.

With a floor span of more than 4 m, an additional stiffening element is installed across the beams - a dividing rib.

From above, the entire floor structure is poured with concrete, which fills the space between the hollow blocks and above them to a height of several centimeters.

Sometimes to increase strength and bearing capacity such an overlap on hollow blocks is arranged with a reinforcing frame made of reinforcement in the form of a mesh with cells of 200x200 mm, which is poured with concrete. True, this significantly complicates the design of the floor.

You can watch a video about the device of a ribbed reinforced concrete floor at the end of the article "Types of floors at home".

Ceilings made of polystyrene concrete

This is a relatively new type of flooring. Three main floor systems are made from polystyrene concrete:

• - mounting ( bearing beams and filling elements);
• - semi-mounted ( mounting plates and bulk layer - reinforced concrete);
• -monolithic system (according to corrugated board).

Polystyrene concrete slabs are made for floor spans:

• up to 4.0 m (thickness 140 mm and weight 150 kg / m 2),
• 4.0 - 5.0 m (thickness 180 mm and weight 190 kg / m 2);
• 5.0 - 6.0 m (thickness 220 mm and weight 230 kg/m2).

Plates and other sizes can be made to order.

A positive feature of polystyrene concrete slabs is their low weight, which leads to a decrease in the load on the supporting frame and the foundation of the house. In addition, such plates have high strength, heat-insulating and sound-proofing properties, as well as ease of installation.