As bearing elements of overlappings in civilian and industrial buildings of the mass construction, predominantly typical reinforced concrete products are used - plates.
Reinforced concrete slabs of overlaps are subdivided:
In cross section (Fig. 2.1) -solid, crowded, ribbed, boxes;
By number of layers (See Fig. 2.1) -single-layer, two-layer, three-layer;
According to options, on four sides (by contour), on the three sides, two opposite hundred-rubles, in the corners (on the frame columns);
The precast floors from reinforced concrete slabs are used, mainly in the walls of wall and frame constituent systems, resting them, respectively, on the walls and beams (riglia) (Fig. 2.1 A, b).In some cases, the PLI is based directly on the columns of the frame, as well as on dr. Plates of overlaps (Fig. 2.2 V, d).
Plates of overlapping reinforced concrete multi-specific(Table 2.1, Fig. 2.3)divided by types:
1PK- 220 mm thick with round voids with a dia-meter of 159 mm, designed to be based on two sides;
1PT.
1PKK - T.same foropportion byfour sides (by contour);
2PK- 220 mm thick with round voids with a dia-meter of 140 mm, designed to be based on two sides;
2Pt.- the same, for painting in three sides;
2pzh
ZPK.- 220 mm thick with round voids with a dia-meter of 127 mm, designed to be supported in two sides;
Zpact- the same, for painting in three sides;
ZPKK- the same, for support in four sides (by contour);
4PK- 260 mm thick with round voids with a dia-meter of 159 mm and cutouts in the upper zone along the contour for support on two sides;
5PK- 260 mm thick with round voids with a dia-meter of 180 mm, designed to be supported on two sides;
6PK- 300 mm thick with round voids with a dia-meter of 203 mm, designed to be based on two sides;
7PK- 160 mm thick with round voids with a dia-meter of 114 mm, designed to be based on two sides;
Fig. 2.1. The main types of reinforced concrete slabs of floors:
a - solid one-layer; b - solid two-layer; in, r - solid three-layer; d - wetty; E is a vigolous two-layer-naya; Well - ribbed: z - ribbed (vest) sanitary and technical; and - ribbed type "pi"; K - ribbed insulated with a lower shelf; l - ribbed type "TT"; M - ribbed folded; N is boxed.
Table 2.1. Plates of overlapping reinforced concrete multi-profile (according to GOST 9561-91)
Note.The side of the slabs takes the size of the side of the plate, not based on the supporting structures of the building, for plates intended for support on two or three sides; Smaller plate size in terms - for plates with support on the contour.
PG - 260 thickness with pear-like voids, pre-designated for support on two sides;
PB is a thickness of 220 mm, manufactured by non-interrupted molding on long stands and embodiment-based for support on two sides.
These types of crowded plates are designed for use in residential and public buildings:
With walls of brick, stones and blocks;
With walls from large panels;
With monolith-concrete walls;
Frame structural system.
Plates 1PK can also be used for production buildings. The use of plates of type 7PCs is limited to low-rise residential houses.
Widespread use of crowded plates in building (Fig.2.4)in many respects, they are determined by the reality:
Strength, rigidity and crack resistance;
Small thickness due to the high emptiness of sections reaching 50%;
Sufficient sound insulation of overlap, ensuring a mass of plates in combination with the floor design;
High fire resistance overlap;
The high level of the factory readiness of the prefabricated elements, which provides a smooth ceiling and an acceptable surface for the floor;
Ability to device in engineering communications plates.
Empties in the stovesdesigned for support on two or three sides are located in the direction of the slab length. In the plates with support on the four stort-us emptiness are located in parallel to any of the Stro-Ron Plate.
Plates are made with recesses or grooves on side faces for education after deputy intermittent or continuous swordsupporting the joint work of the slabs of overlapping on the shift in the rizonal and vertical directions.
Plates designed to be supported on two or three sides of more than 4.8 m long have pre-tense fittings.
Strengthening the ends of the slabs,required during the transmission of the load is achieved by a decrease in the cross section of voids on the supports (on the one hand) and filling the voids with concrete (on the other side).
Plates may have (in accordance with the project of a specific building) mortgage parts, reinforcement releasants, local cuts, holes, etc. Additional constructive parts. For lifting and mounting, plates include mounting loops or special gripping devices (holes).
Multipurist plates are made of heavy-tone classes B15-B25 and the structural lightweight concrete of the dense structure of the average density of at least 1400 kg / m 3.
Multipurb plates with support on two sides (beam plates) are calculated in the longitudinal director for bending as freely lying single-span balls. According to the calculated values \u200b\u200bof bending moments and in pepper forces, the required number of longitudinal and transverse reinforcement is prescribed. The longitudinal working Arma Tour with a diameter of 10-18 mm Classes A-IV and A-V is included in the lower grid. The transverse reinforcement is installed in the extreme edges of the sections, and if necessary, on average, according to the results of the calculation on the transverse force. An example of the arrangement of the hollow plate is shown on fig. 2.5.
In the manufacture of PB type plates, modern method of continuous unoperable formon heated long stands. The forming machine with the address feed of the concrete mix is \u200b\u200bre-re-cooked at a speed of 0.6-3.5 m / min. The addressing part of the track guarantees concrete ripening up to 70% of the strength in 16 hours, after which a diamond disc with a computer computer control cuts the reinforced concrete linen on the plates of any given length (2.4-9 m), including Trapezoidal in the plan. The nominal width of such plates is 1.2 or 1.5 m. The reinforcement is made by straining rods of the wire fittings Clast owls in and and BP and a diameter of up to 8 mm or sevenproof the cable reinforcement of class K-7 with a diameter of up to 15 mm.
Fig. 2.5. Reinforcement of the hollow plate: A - cross section; b - longitudinal section; 1 - lower welded grid; 2 - longitudinal working fittings; 3 - vertical flat welded frames; 4 - mounting loop; 5 - upper welded mesh; 6 - protective layer of concrete; 7 - distributor - naya fittings.
Multipurist plates are used in the overlaps of cable and monolith-concrete buildings with a longitudinal-wall and cross-wall structural systems. (Fig. 2.6).
The role of overlapping as hard drives is the pre-entertainment of all vertical and burning loads on them, as well as in ensuring the unity of the carrier island when the power of the building walls is perceived. Therefore, the plates have anchor connections among themselves and with carrier walls (See Fig. 2.6).
If it is necessary, the vertical communication device between the plates or between the wall and the slab is equipped with a gap to 300 mm, which is subsequently deposited with concrete with the installation of flat reinforcing car casas (nodes 5.6, 9 - Fig. 2.6).
In buildings with monolith-concrete walls, the blocks of multi-piscular plates can be performed by once-carvedor effectiveschemes (Fig. 2.7).At the same time, the design of nodes of mating overlap with walls should ensure unobstructed passage through them vertical wall fittings.
Table 2.2. Plates of overlapping reinforced concrete solid for large-pointed buildings (according to GOST 12767-94)
| Plate thickness, mm | Type of plates when painting construction structures | ||
| in four sides | for three sides | on two sides | |
| 1p. | - | - | |
| 2p. | - | 2PD | |
| Zp. | 3pt | 3PD | |
| 4p | 4pt | 4PD | |
| 5p | 5pt | 5PD | |
| 6P. | 6T. | 6PD |
With free supporting on the wall (split circuit), the slabs of overlaps must have support protrusions, incoming the edge of the wall to a depth sufficient for the anchoring of the longitudinal fittings of the plates, but not less than 70 mm. In this case, the compounds of the slabs in addition to the specified method can be carried out by depowcing reinforcement frames in the hollows of the plates ( fig. 2.7 a).
With hard connections with walls (continuous diagram), the slabs of the floors must have reinforcement-start - straight, loopers, hooks. The rigidity of the nodes is pre-tired by the welding of the upper and lower release of the reinforcement (Fig. 2.7 b),association of looping issues and an ante-performance with the help of horizontal reinforcement terminal (Fig. 2.7 V, d).
Fig. 2.7. Conjugation of hollow slabs overlapping with monolith-nobtonic walls:
a - freely opened plates on the inner wall (circuit); B, B - rigid knots of pairing slabs of overlapping with inside-rhenium walls; M is the same, with an outer wall; 1 - interior wall; 2 - outer wall; 3 - Multiplass plate; 4 - mallet; 5 - Armature frame; 6 - reproduction straight; 7 -Petle reinforcement.
In low-rise buildings and apartments in two levels, there is a need for a device of staircase pro-emes in overlaps. These openings can be designed without any additional vertical supporting structures using rolling steel profiles based on walls or main plates of overlaps (Fig. 2.8).
Reinforced concrete solid slabs of floors for large-pointed buildingsdivided into types of their thickness and a design of the wall panels (Table 2.2).
The stove thickness is taken from 100 to 200 mm. The highest application is found from a heavy concrete plate 160 mm.
Rely plates on the walls in four sides (by contour), in three or two opposite sides. Based on this, the working fittings plates are located in two or one direction. Plates of more than 4.8 m long, designed to be based on two sides, are usually pre-stressed fittings.
Coordination Sizes Plates: Length 3.0-7.2 m (Che cut 0.3), width 1.2-6.6 m (0.3). For the length of the plate at-bottom: when it is based on four sides - a smaller plate size in terms of plates; When it is based on three or two sides, the size of the side of the plate, which is not based on the supporting structures. Under the terms of transportation, one of the sizes of the slab should not exceed 3.6 m.
Plates have (Fig. 2.9):
Steel mortgage parts, reinforcement releases and other structural elements for connecting with adjacent building structures;
Channels of hidden wiring, sockets for boxes and sockets, plastic boxes with anchors for fixing lamps;
Fig. 2.8. The device of openings for intra-quarter stairs in overlaps with multi-retail plates: A - when adjacent to one wall; b - when joining two walls; A, B, B, G - nodes.
Holes and openings for passing engineering communications.
Side faces on the sides of the Types of PD and PT types, pre-assigned to docking in the span (without support on the walls), are performed with closed or unlumbed recesses, the shape of which ensures the joint operation of the conjugated slabs on the shift in the horizontal and vertical directions after the seams of seams between the stoves . The plates may have a recess for the formation of the key also on the sides resting on the wall panels.
Depth of the Outwear Plate Plate on External Steers - 90 mm (Fig. 2.10).The nominal size of the depth of the platform for the inner walls is equal to half the thickness of the wall panel minus 10 mm, except in cases of supporting the plates on the walls of the staircase, where the support plates are accepted for the thickness of the walls. Opportuning slabs of floors on the walls is carried out by cement-sandy solution. All steel bonds of the plates of the breakdown between themselves and with the panels of the outer walls - welded. It is envisaged for at least two connections for each of the sides of the slab of the overlap.
The overlap of buildings with reinforced concrete frames is solved using three types of products:
Crowded plates with a height of 220 mm;
Ribbed plates with a height of 300 or 400 mm;
Plates of type "TT" and "T".
Fig. 2. 9. Plate of overlapping reinforced concrete solid type PT for large-pointed buildings:
1 - mortgage corner for connecting plates on welding; 2 - slop-alcohol loop; 3 - looping for connecting plates; 4 - tweeted for ventblock; 5 - opening for communications; 6 - Channel of hidden wiring; 7 - Box for fastening the lamp.
Multi-public platesfor buildings with reinforced concrete frames of the 1.020.1 series are used for overlapping spans 3.0; 6.0; 7.2; 9.0 M. (Fig. 2.11).Coordination sizes in width - 3 m (only for a span 6 m); 1.5; 1.2; 0.9 m. Together with them, as a passage of vertical engineering communications, the ribbed (vertical) plates is also used in the passage of vertical engineering communications, with a 120 mm high with a width of 1.5 m.
Multipurist plates are placed on the Riga shelves or diaphragms of stiffness in a layer of cement-ra with a thickness of 10 mm. Flat reinforcement frames are installed in the seams between the plates and is poured with cement-sandy mortar. The intercolatular slabs of the frame of the frame are also installed on the shelves of the riglels (diaphragm of rigidity) along the internal axes of buildings and with the help of reinforcing assembly products, arc welding (node \u200b\u200bb - see fig. 2.11).
Fig. 2.10. The circuit of the assembly plan and knots of pairing plates of ne-reprints:
1 - slab overlap; 2 - outer wall panel; 3 - in-nya wall panel; 4 - connecting rod; 5 - Concrete of Camo-Nitching; 6 - connecting bracket; 7 - cement mortar; 8 - mounting loop; 9 - slab overlap of the loggia.
Ribbed reinforced concrete plates of overlapping height 300 mmthey are intended for overlappings of many public and industrial buildings for various purposes with a pitch of a column of 6 m with a maximum load on the slab to 26 kPa (2600 kgf / m 2). Shapes, sizes of plates and their purpose are indicated in table. 2.3and on fig.2.12.
The plates may have holes with a diameter of 400, 700 and 1000 mm, cutouts in shelves, recesses on the outer edges of the longitudinal ribs for the device of concrete knaps between adjacent plates, additional mortgage parts.
Ribbed stoves install "dry" on the shelves of riglels or diaphragms of stiffness and weld to the shelves of riglels.
The plates are made of heavy concrete of the average density of 2200 kg / m 3 or light concrete of a dense structure with a density of at least 1600 kg / m 3.
Fig. 2.11. Multipurpost plates with a height of 220 mm and their proposition in the floors of frame buildings: a, b - in the span of the riglels 3 m; in, g - in the span of riglels 6 m; d, e-in the span of riglels 7.2 m; Well, s - in the span of riglels 9 m; 1 - row-water stove; 2 - intercolanted (connected); 3 - intercolatular at-wall; 4 - plumbing ribbed stove; 5 - transverse reiglel; 6 - longitudinal reiglel; 7 - Armature frame; 8 - Ko-Lonna; 9 - connecting rod.
Ribbed reinforced concrete plates of overlapping height 400 mmdesigned for overlappings of production buildings for various purposes with a step of Ko-Lonn frames 6 m with a maximum load on the slab to 52 kPa (5200 kgf / mg 2).
Plates, depending on the method of their support on the Ri-gel of the building frame, are divided into two types (Table 2.4):
1p - with support on the shelves of riglels;
2p - with support on the top of the riglels (Fig. 2.13).
Slabs type 1P are provided for eight sizes (1P1-1P8), type 2P - one size (2P1).
Reinforced concrete precompanied tension plates of the TT type and "T"(Fig.2.14)designed for overlaps of public and industrial buildings with a pitch of columns 9 m (coordination slab length).
Fig. 2.12. Ribbed plates with a height of 300 mm and their location in the floors of frame buildings:
a, b - in the span of riglels 3 m; in, g - in the span of riglels 6 m; d, e - in the span of riglels 9 m; 1 - ordinary plate; 2 - ordinary and intercalone (connected); 3 - intercolatular wall; 4 - sufficient solid stove; 5 - Rigel transverse; 6 - Rigel longitudinal; 7 -armatical frame; 8 - Concrete of insulating.
Table 17.5. Plates of overlaps reinforced concrete ribbed 300 mm high
The TT plate with two ribs in the longitudinal director has a width of 3 m and can also be used as a series, and as an intercalone (connected). The stove "T" with one edge has three sizes: 1,5m-row
and intercolanny; 1.3 m - Private Dobly; 1.7 m - intercolanted wall. The height of all plates of type "TT" and "T" 600 mm - corresponds to the height of reinforced concrete rigales. Opportion is made on the shelves of bolts thickened knockers with trimming of longitudinal rebar (Fig. 2.14 g), which allows you to solve the overlap withoutprotruding individual elements.
Architectural expressiveness is different castle ceilings overlapspublic Supplies made of reinforced concrete plates having not only longitudinal, but also transverse (sometimes diago-mall) ribs of the same height (Fig.2.15).In this case, two types of plates are used - ordinary and side (intercolacon). The overlap is solved on a square set of columns with a pitch of 6 or 7.5 m. The modular sizes of shi-rin plates and the steps of their ribs are taken 1.5 m. Private plates are based on the riglels only in two hundred rubles, side - by Three. The support parts of the plates have trimming from the bottom to the height of the rigel shelf.
Fig. 2.14. Plates of type "TT" and "T" and their location in the breakdowns of frame buildings:
a - in the span of riglels 3 m; b - in the span of riglel 6 m; B - in the proli-those riglels of 9 m; M - node of supporting the plates on the riglel; 1 - plate-lade plate and an intercalone width of 3 m; 2 - the same, 1.5 m wide; 3 - Private Turning Plate; 4 - intercolatular wall; 5 - Ri-gel at the end of the building; 6 - fine-grained concrete.
The overlap is one of the structural elements of the building, dividing its inner space on the floors. The overlap refers to the bearing elements, as perceives and transfers the load from its own weight, as well as from equipment and people on the walls, supports, riglels. It is performed from reinforced concrete plates.
By location in the building they can be divided into:
- Advanced.
- Internet.
- Attic.
By their design, they are divided into beam and boiling off. They are made by the factory method from reinforced concrete and are divided into assembly-monolithic, multi-profile, manufactured from heavy concrete and cellular concrete. Overlappings must meet such requirements as strength, soundproof, stiffness, non-corruption and waterproof.
Mostly reinforced concrete plates from which overlaps are made are multi-handstone structures and are made with polygonal, oval and round voids. The largest distribution in the construction of a plate with round voids of PNO and PC, which bears the ability of which - 800kg / m2. High strength is distinguished, full factory readiness for installation, manufacturability. Such plates are relying on two sides. Put them on the bearing walls. Overlapping from such plates is used in the stepping of the bearing walls up to 9 m. Durability, fire resistance, the necessary spatial rigidity, the stability of the building - this is what distinguishes such overlaps.
Conventional standards of hollow plates:
- length - 2.4-7.2 m;
- width - 1-1.8 m;
- thickness - 220 mm.
The basis on which the plates are stacked may be from:
- brick;
- reinforced concrete panels;
- aerated concrete;
- foam blocks.
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Depth of supporting overlapping and necessary equipment for work
Depending on the basis for which the magnitude of the depth of the content is taken into account.
The slate length, its weight, the thickness of the supporting wall, constant or temporary load on the plate on top, the seismic resistance of the building are also taken into account. Calculations are quite complex and made by experts. The individual developer is enough to focus on the parameters of the manufacturer, labeling their products, and clearly follow them. The clarity of the recommendations of manufacturers will save from errors in the design and installation of void structures, otherwise the consequences will entail expensive and labor-intensive steps.
- on large-pointed walls - 50-90 mm;
- on brick walls - 90-120 mm;
- based on aerated concrete - 120 mm;
- on foam block walls - 120 mm;
- on the outer walls, the opiir is negotiated up to 250 mm.
Necessary equipment, materials and tools:
- anchors;
- cement mortar;
- level or level - to determine the height difference between working surfaces;
- rigels - support beams;
- mounting Lomik;
- plumb - to test the vertical surface;
- inventory stage;
- swarf cord;
- slings;
- autocran with a loading capacity of 25 tons.
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Installation of overlapping in brick buildings
For installation work requires a brigade of four. The crane driver sues (walls) - stove. The rigger is occupied by the slabs by the four -roadwide sling. Two installers, while on both sides of the supports of the mounting plate, take it, unfold and then the guide actions coordinate its lowering to the specified position. After the assembly lobs, they perform a small richness of the plate, even before the removal of the sling.
In brick buildings, they are laid on the walls and riglias. Rigels are placed on reinforced concrete pillows with a sling. They must be laid in brick walls during masonry. Before placing the riglel, it is necessary to check the horizontal of the pillows. The difference between them, or rather, their surfaces should not exceed 10 mm. Then the riglee is brought to the right position by assembly lomits. The installers themselves are located on the stage. Rigel necessarily need to move only on perpendicular to the longitudinal axis, using the blade of the assembly lomka. Otherwise, the stability of the walls serving the riglu will be broken. After the reconciliation of verticality (plumbing) and horizontal (level), and only then the reiglel is fixed to the base. When these works are completed, the slings are removed.
The use of hollow slabs is possible in buildings or with transverse, or with longitudinal carriding walls, because they are based on two sides. Then follows the anchoring of the overlap, which is the fastening of the placed slabs of the overlap with the outer walls and between themselves. Anchors usually have no more than 3 m away from each other.
Before placing slabs, the horizontal surfaces of the working surfaces is re-selected. Must align the wall masonry.Because a fairly large area of \u200b\u200bempty floors will be sensitive even to small irregularities of the foundation. Plates just will swing. Revealed irregularities are paired by additional isolation strips.
And only after that they fall on the plates, where cement mortar is already laid. In order to obtain a single rigid horizontal overlap, the plates are connected to each other and with the outer walls with steel anchors, which are fixed to the mounting hinges. The ends of the slabs of the floors are connected to the masonry of the brick wall M-shaped anchors. Then they are close to a mortar mixture in order to protect against corrosion.
When the plates are based on the inner walls, the composite anchors obtained by connecting them to welding are used. The gaps arising between the plates are filled with bricks used in the main masonry. Plates are placed on the mortar mixture.
The ceiling after laying the plates is checked on horizontal. When the mismatch is detected between the adjacent plates, they are raised with the help of a crane and hang the mortar bed, after which they are replaced again. When the reconciliation is over, the slabs fix the anchors that lay in the masonry. The adjacent plates are combined with each other for the mounting loops by anchors.
In hollow flooring, if the support goes to the outer basis, empties are filled with heavy concrete or concrete traffic jams by about 12 cm. This is done for the purpose of insulation. The same is produced in hollow boards, which are based on the inner bearing walls. The voids are filled in order to prevent the destruction of the reference parts of the plates under the pressure of the structures located above, as they are their edges are the brittle.
The jumpers, which are supporting, that is, those on which the main load from the overlaps is installed, are installed, lifts for mounting loops lifting and placing on the mortar mixture. Private jumpers are handed to manually, given the area of \u200b\u200bthe content and horizontality.
The reliability of supporting overlap on the bearing walls provides a safe reliable and long-term possibility of exploitation of the entire building. The design stability of engineering structures depends on competent execution. Therefore, the opacity of the floor overlapping slabs is regulated by SNiP.
Parameters that have determined the magnitude of the content
The depth of overlapping on the walls depends on the following factors:
- appointments and type of buildings - residential, administrative, production;
- material and thickness of bearing walls;
- the magnitudes of the overlapping span;
- the size of reinforced concrete structures and their own weight;
- the species acting on the overlap of loads (static or dynamic nature) which of them are constant and what time;
- values \u200b\u200bof point and distributed loads;
- seismicity of the construction area.
All the factors listed above are necessarily taken into account when performing calculations of reliability of a constructive. In accordance with the current regulatory documents, supporting the slab overlap 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 smaller outflows, the heavy weight of the elements, together with active loads, will have a direct impact on the edge of the masonry, which can lead to its gradual destruction.
On the other hand, a larger flaw will already be a kind of pinching of reinforced concrete elements with a weight transmission from the above-mentioned section of the wall on their ends. The result is cracking and slow destruction of masonry walls. Also, at the approach of the ends of the products to the outer surfaces of the walls, the heat loss in reinforced concrete elements occurs with the formation of cold bridges, leading to the formation of cold floors. The cost of details is proportional to their length, so excessive pinching will lead to an increase in the cost of the structure.
Removement knot Overlapping plate on a brick wall
When building brick buildings with a device of overlapping from precast concrete plates, the masonry is carried out in full thickness to the design nose of the ceilings. Next, bricks are laid only on the outside of the walls for the formation of a niche in which the plates can be put.
In support nodes, it is important to comply with the following conditions:
- the ends should not be restricted into the brickwork, so for the most frequently used in the practice of Fall in 12 cm, the width of the niche ≥ 13 cm;
- the solution on which the plates are stacked, the same brand as a masonry;
- voids in the channels are closed from the ends with the help of concrete liners, which will protect ends from destruction when squeezed under loads. The manufacture of concrete liners is performed on factories with delivery when buying plates, in the absence of liners, channel emptiness is filled with concrete B15 directly on the construction site.
On the end brick walls, slab reinforced concrete products lie down and one side side. In this case, the minimum supporting plates of overlapping on the end walls is not normalized. But in order to avoid the destruction of the product when squeezing the wetting channel, the installation must be made so that the laying lay down above the masonry does not fall on the extreme emptiness of the design and the shoulders acting from the load of the moments must be minimal values.
Requirements for Armopoyarov Device for Overlapping Plate
In buildings with walls from blocks made of light concrete (agencies, gas-concrete, foam concrete, polystyrene-concrete), having small strength characteristics of the overlap must necessarily rely on the reinforced belt. Armopoyas is arranged throughout the perimeter of the building. Armopoyeas height under the ceiling plate from 20 to 40 cm. Connection of reinforced belts with overlap parts should be mechanically durable, for which anchor devices are used or docking by reinforcement rods of the periodic profile using electric welding.
A number of the following requirements are presented to the design:
- the belt should be arranged to the entire width of the walls, for outer width ≥ 50 cm, it is permissible to decrease ≤ 15 cm for laying the insulation;
- reinforcement made with the help of engineering calculations should provide sufficient mechanical strength to perceive the loads from its own weight of reinforced concrete elements and the above-skilled constructs;
- concrete ≥ class B15;
- the belt is a kind of cold bridge, so its mandatory insulation needs to prevent the destruction of aerated concrete blocks from the accumulated moisture;
- reliability of clutch with carrying walls.
Opportuning slabs of overlapping on aerated concrete blocks of bearing walls for reinforced belts is performed in compliance with the following normalized values:
- at the end ≥ 250 mm;
- by the rest of the contour ≥ 40-k mm;
- when describing the 2nd sides of the span ≤ 4.2 m - ≥ 50 mm;
- the same when I span ≥ 4.2 m - 70 mm.
Aerated concrete blocks are not able to withstand high loads, the material begins to be subjected to various deformations. Aropoyas, taking on all the loads, evenly distributes them, thereby ensuring not the destruction of the structure.
Installation of ceiling slabs on gas-silicate blocks is also performed with a mandatory device of monolithic reinforced concrete belts. Required support values \u200b\u200bcorrespond to the above values \u200b\u200bfor walls from aerated concrete blocks.
During the production of installation work, the following conditions must be performed:
- compliance with the symmetry of laying elements in flights;
- ends of the plates should be aligned on one line;
- all elements should be located in one horizontal level (control is carried out using a construction level), permissible deviation in plane plane ≤ 5 mm;
- the thickness of the solution under plates ≤ 20 mm, the solution should be freshly prepared, without the beginning of the gripping process. Invalid additional dilution of the mixture with water.
Invalid laying instead of Armopoyas series of bricks or reinforcement grids.
The construction of the house is in itself a lot of nuances, which many beginner builders do not even know. In particular, one of these "pitfalls" is the flooring node, which is, a whole technology that is responsible for the durability of the house.
That is why it is necessary to approach the decision of this problem with full responsibility, at least familiar with the consequences of a negligence relationship.
Acquaintance with floors
The opening plate of the ceiling plate on the brick wall is nothing but a butt of two planes: vertical and horizontal. Many private developers beat this moment in different ways, but it does not always work correctly, and even more so reliably.
Therefore, in order to avoid adverse consequences related to expensive repairs, it is necessary to prepare in advance.
Types of used materials for overlaps
These overlaps themselves are made from reinforced concrete slabs, the most reliable of the materials available.
That's just there are some differences in the production process, this is due to the type of structure:
- Cellular concrete.
- Collected-monolithic - The most popular of all submitted.
- Hard concrete-based. This type refers to many materials, since impurities of heavy concrete are present in various products.
- Multi-publication.
All of the above overlaps of brick buildings are used under certain conditions, depend on the plan of the structure, the load carried out and the size of the span.
It should be divided into two categories:
- Inter-storey floors in a brick house are used for multi-level houses. They are mounted in the bearing wall on a special lining that ensures reliable fixation of the product. At the same time, the depth is very important with which the overlap will fall on the wall.
- An attic type does not experience such high loads, so mounted in the wall without lining.
For your information! If you decide to build a multi-storey brick house with your own hands, you should give your preference to overlapping from precast concrete plates. They have not only increased strength, but also a huge bearing capacity, as well as, if so we can speak available by installation.
Remaining knot - find a solution
In order for the restraint of overlapping slabs to brick walls, it was able to withstand high loads, little use of durable materials, it requires the most subtle approach.
- At first, It is necessary to correctly calculate the support node. Consider that it can only be implemented on the carrier wall, but can not be associated with the partition.
Note! Each product (building material) has its markings, which indicates its specific features: seismic resistance, carrying capacity and others. This applies not only to reinforced concrete slabs, but also bricks used as supporting structures. For example, double silicate brick M 150 is not the best solution for the construction of a multi-storey house.
- SecondlyAll calculations and plan solving the problem must be verified with GOST 956-91 and additional project documents. Otherwise, you may be denied construction.
For example, familiarize yourself with the marking of PC plates 42.15-8t, where PC is overlapped with round emptiness, 42.15 - product dimensions in decimeters (length 4180, width 1490). The figure 8 is the maximum permissible load on the stove, which is 800 kgf / m2, and the letter T, following 8 - the index of heavy concrete used for the production of this stove.
There is also a certain standard of how the operating plates should look like on a brick wall - from 90 to 120 mm. It is this size that is worth withstanding, adjusting to it.
Here you should consider two main points:
- Reliability of the base of the house, which should be designed for high loads. It is necessary to avoid those places where the foundation can be weakened, which will lead to an uneven shrinkage of the structure, as a result of which - the curvature of the overlap.
- The width of the foundation in no case should be less than brickwork. In this case, the deformation of the bearing walls is inevitable - the load load will affect bricks, on the weakening of the cement mortar.
It is necessary to navigate on the thickness of the plate in relation to the thickness of the carrier wall. And this is provided that high-quality construction brick is used, which meets standards and gta stations.
Fixation of slabs of the overlap
Anchoring slabs of overlapping in a brick house is used to enhance the design, increase strength and reduce the probability of deformation of the material. This method is extremely difficult to implement on their own, so it is better to trust his professionals, even though the price may be unpleasant. The main thing in construction business is reliability and durability.
One feature that should be felt - the location of the anchors is possible through the stove. However, there is a limit - 3 meters from each other, this is a permissible maximum.
For your information! The anchor is also used to fasten the precast concrete plates among themselves.
Now you understand that such a node is a supporting plate overlapping on a brick wall, which is connected with it and what it affects. That is why you can protect yourself from any unfavorable moments at the design stage.
Output
It is important not only to put the plates correctly, but also to build the foundation, withstand the time of drying the solution, make a masonry of bricks with a minimum stall of the seam, as the statement statement. All this can be done yourself, but if you doubt, it is better to entrust the work of professionals.
Plates of overlapping
Factory slabs of overlappings - a very popular option of overlapping in ILS, because Alternative - Monolithic concrete overlap - a much more labor-intensive thing, difficult for inexperienced private developers. In contrast to the monolith, the plates go with the maximum load guaranteed plant, which is more than enough in a private house.
Description
On the slabs of overlaps in Russia there are two GOST:- GOST 9561-91 "Plates of overlapping reinforced concrete multi-consist for buildings and structures. Technical conditions. "
- GOST 26434-85 "Plates of overlapping reinforced concrete for residential buildings. Types and basic parameters. "
- 1PK - 220 mm thick with round voids with a diameter of 159 mm, designed for support on two sides;
- 1Pt - the same, for support in three sides;
- 1PKK - the same, for support in four sides;
- 2PC - 220 mm thick with round voids with a diameter of 140 mm, designed for support on two sides;
- 2Pt - the same, for optilation in three sides;
- 2PKK - the same, for support in four sides;
- 3PK - 220 mm thick with round voids with a diameter of 127 mm, designed for support on two sides;
- 3Pt - the same, for fusion in three sides;
- 3PKK - the same, for support in four sides;
- 4PK - a thickness of 260 mm with round voids with a diameter of 159 mm and cutouts in the upper zone on the contour designed to be supported on two sides;
- 5PC - a thickness of 260 mm with round voids with a diameter of 180 mm, designed to be supported in two sides;
- 6PC - a thickness of 300 mm with round voids with a diameter of 203 mm, designed to be supported on two sides;
- 7PC - 160 mm thick with round voids with a diameter of 114 mm, designed for support on two sides;
- GHG - 260 mm thick with pear-like voids designed to be supported on two sides;
- PB is a thickness of 220 mm, manufactured by continuous molding on long stands and designed to be supported on two sides.
In this list there are no plates of floors of the type PNO, which are found from manufacturers of the progress. In general, as I understood, manufacturers of slabs are not obliged to observe GOST (Government Decision of December 1, 2009 No. 982), although many produce and label plates according to GOST.
Manufacturers produce plates of different sizes, you can almost always find yourself the necessary size.
Overlapping slabs in most cases are manufactured preloaded (paragraph 1.2.7 GOST 9561-91). Those. The reinforcement in the plates is stretched (thermally or mechanically), and after pouring the concrete is released back. Compression efforts are transferred to concrete, the stove becomes stronger.
The ends of the plates that are involved in the contents, manufacturers can enhance: fill the round empties to concrete or to narrow the cross section of emptiness in this place. If they are not filled with the manufacturer and the house is obtained heavy (the loads of the walls on the ends increase accordingly), then the voids in the area of \u200b\u200bthe ends can be filled with concrete.
Plates usually have special hinges outside, for which they climb the crane. Sometimes the reinforcement loops are inside the stove in the open cavities located closer to the four corners.
The slabs of the floors according to paragraph 1.2.13 GOST 9561-91 are indicated as: the plate type - length and width in decimeters - the calculated load on the plate in kilopascals (kilogram-force per square meter). Also, a class of steel reinforcements and other characteristics may be indicated.
Manufacturers do not bother with the designation types of plates and in the pricea usually write the type of plate only PC or PB (without 1PC, 2PK, etc.). For example, the designation "PC 54-15-8" means a plate 1PC with a length of 5.4 m and a width of 1.5 m and with the maximum allowable distributed load of about 800 kg / m 2 (8 kilopascals \u003d 815.77 kilograms / m 2 ).
The slabs of the overlaps there is a lower (ceiling) and the upper (sex) side.
According to paragraph 4.3 of GOST 9561-91, the stoves can be stored in a stack of not more than 2.5 m high. The lining under the lower row of plates and gaskets between them in the stack should be placed near the mounting loops.
Opporting plates
Plates of overlaps have a zone of support. According to clause 6.16 "The benefits for the design of residential buildings. 3 (K SNIP 2.08.01-85) ":The depth of the prefabricated plates on the walls, depending on the nature of their support, it is recommended to take at least mm: when describing the contour, as well as two long and one short sides - 40; when working on two sides and span plates of 4.2 m and less, as well as on two short and one long sides - 50; When painting on two sides and spit plates more than 4.2 m - 70.
The slabs also have a series of work drawings, for example, "Series 1.241-1, release 22". In these series, the minimum depth of the support is also indicated (it can vary). In general, the minimum depth of the plates must be clarified by the manufacturer.
But with the maximum depth of supporting the plates there are questions. In various sources, completely different meanings are given, somewhere it is written that 16 cm, somewhere 22 or 25. One friend on YouTube assures that a maximum of 30 cm. Psychologically, it seems that, the deeper the slab stuffing into the wall, the more reliable will be. However, the limitation of the maximum depth is exactly there, because if the stove is too deep into the wall, then the bending loads "work" in a different way. The deeper the plate enters the wall, the usually the permissible voltages from the loads on the support ends of the plate. Therefore, the magnitude of the maximum content is better also from the manufacturer to find out.
Similarly, it is impossible to describe the plates not in the Oppulating zones. Example: On the one hand, the stove lies right, and the other side hangs, leaning on the middle carrier wall. Below I drew it:
If the wall is built from the "weak" wall materials like aerated concrete or foam concrete, then it will be necessary to build armooosas to remove the load from the edge of the wall and distribute it to the entire area of \u200b\u200bthe wall blocks. For warm ceramics, Armopoyas is also desirable, although instead you can put several rows of ordinary durable full-scale bricks, which does not have such problems with support. With the help of Armopoyas, it is also possible to ensure that the plates will form a flat plane together, so it will not be necessary to costly the ceiling plaster.
Plate laying
The plates are put on the wall / armopoyas on the cement-sandy solution with a thickness of 1-2 cm, not more. Quote from the joint venture 70.13330.2012 (updated edition SNIP 3.03.01-87) "Bearing and enclosing structures", paragraph 6.4.4:The ceiling slabs must be laid on a layer of a thickness of no more than 20 mm, combining the surface of adjacent plates along the seam from the side of the ceiling.
Those. Plates are aligned so as to create a smooth ceiling, and the uneven floor can then be aligned with a screed.
Plates when installing are placed only on those sides that are provided for the Oppulating. In most cases, these are only two sides (for PB plates and 1PCs), therefore, it is impossible to "pin" the wall of the third side, not intended for support. Otherwise, the stove squeezed from the third side will not correctly perceive the loads from above, cracks may form.
Stacking slabs of floors should be made before the construction of interior partitions, the plates should not initially rely on them. Those. First you need to give the stove "Proviscribe", and only then build the nonsense interior walls (partitions).
The gap between the stoves (the distance between the sides) can be different. They can be placed closely, and it is possible with a gap of 1-5 cm. The space of the gap between the ceiling slabs is then close to the solution. Typically, the width of the gap is obtained "by itself" when calculating the desired number of plates, their size and distance that you want to overlap.
Plates of overlapping after laying can be removed with each other with, for example, welding. This is done in seismic regions (Ekaterinburg, Sochi, etc.), in ordinary regions it is not necessary.
In places where it is difficult to choose the slab of the overlap or it does not work correctly to mount, the monolithic overlap should be poured. You need to pour it after mounting the factory plates to correctly set the thickness of the monolith. You need to make sure of the rigidity of the installation of the monolithic overlap, especially if the staircase will rely on it. The space formed between the ceiling slabs does not always have a trapezoidal form either form with stove protrusions to which you can rely on. If the monolith is rectangular and is not held on the beveled edges of the adjacent plates, it can simply fall out.
Insulation
Ends of the slabs of overlaps lying on the outer walls, you must insulate, because Reinforced concrete has a greater thermal conductivity and a stove in this place becomes cold bridge. As a heater, an extruded polystyrene foam can be used. Drew an example:
In the carrier outer wall, 50 cm thick includes a plate with 12 cm, which from the end is insulated with an EPPS (orange color) with a thickness of 5 cm.