RU2637006C1 - Hollow-core floor slab - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: hollow-core floor slab contains the lower and upper reinforced belt, voids, monolithic areas and embedded items. Monolithic areas are made in all voids of the end sections of the slab. The embedded items are installed in at least two voids. The embedded items are made in the form of a corner with anchor elements welded to the inner side of the angle, which is turned by its open part with anchor elements to the body of the slab. The angle has two horizontal anchor elements which are connected at the free ends by a plate, and one vertical anchor element extending between the horizontal anchor elements and terminating in a plate. All anchor elements are recessed in monolithic areas of the voids of the slab. The angle is installed in such a way that the upper leg of the angle is buried in the upper part of the slab, and the end leg is buried in the end part of the slab.

EFFECT: increase in the strength of butt joints.

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Description

The present invention relates to elements of building structures, namely to hollow core slabs.

A patent of the Russian Federation for utility model No. 147226, IPC E04G 23/02, “STRUCTURE OF REINFORCEMENT OF REINFORCED CONCRETE MULTI-VESSEL FLOOR PLATE”, is known. The reinforcement structure of a reinforced concrete multi-hollow floor slab includes additional reinforcement, which is placed and monolithic in grooves made in the stretched zone of the slab. The grooves are placed in the areas of the voids of the plate, connected to the voids and provided with clamps, which are placed additional monopolistic fittings. In addition, the additional monolithic reinforcement is provided with at least two monolithic anchors.

The disadvantage of this device is the unreliability of the connection of the plate with other plates and building elements.

Closest to the claimed invention is a patent of the Russian Federation for invention No. 2024707 IPC E04C 2/04, E04B 5/02, "MULTI-EMERGENCY REINFORCED CONCRETE FLOOR PLATE AND METHOD FOR ITS MANUFACTURE". The inventive slab contains located in the body of concrete lower prestressed reinforcement, differently sized alternately located voids and upper reinforcing mesh with a length equal to 0.1-0.2 length of the slab installed at the ends of the slab. In the manufacture of the slab, the mold is filled with activated concrete mixture with a hardness of 5-10 s. After compaction of the mixture on a vibrating platform, sealing and calibration of the upper part of the plate with a rotating roller is carried out.

The disadvantage of this technical solution is the inconvenience and low reliability of the connection of the slab with other building elements.

The task of the invention is the creation of a hollow core slab providing strength butt joints in multi-story construction.

The problem is solved due to the fact that the multi-hollow floor slab contains the body of the slab, the lower and upper reinforced belt, voids, monolithic sections and embedded parts. Monolithic sections are made in all voids of the end sections of the plate. Embedded parts are installed in at least two voids. The embedded parts are made in the form of a corner with anchor elements welded to the inside of the corner, turned with its open part with anchor elements into the body of the plate. The corner has two horizontal anchor elements that are connected at the free ends by a plate, and one vertical anchor element, passing between horizontal and ending with the plate. All anchor elements are recessed in monolithic sections of the voids of the plate. The corner is installed in such a way that the upper shelf of the corner is recessed in the upper part of the plate, and the end shelf is recessed in the end part of the plate, and the lower edge of the end shelf of the corner is located at the same level with the lower edge of the plate. The length of the upper flange of the corner of the embedded part is always longer than the width of the supporting element of the object under construction.

The invention is illustrated by drawings:

FIG. 1 - vd from the end of a fragment of a hollow core slab with monolithic sections and embedded parts;

FIG. 2 is a view of a fragment of a hollow core slab with monolithic sections and embedded parts;

FIG. 3 is a view of a fragment of a multi-hollow floor slab dissected in the void region with a part of the monolithic section and the longitudinal half of the embedded part, while the slab is supported on the supporting element of the building under construction;

FIG. 4 is a view of a embedded part.

The multi-hollow floor slab 1 contains the body of the slab 2, the lower reinforced belt 3 and the upper reinforced belt 4, voids 5, monolithic sections 6 and embedded parts 7. Monolithic sections 6 are made in all voids 5 of the end sections 8 of the plate. The embedded parts 7 are installed in at least two voids 5. The embedded parts 7 are made in the form of a corner 9 with anchor elements 10 welded to the inner side 11 of the corner turned with its open part 12 with anchor elements 10 into the body of the plate 2. The corner 9 has two horizontal anchor elements 13, which are connected at their free ends by a plate 14, and one vertical anchor element 15 extending between the horizontal anchor elements 13 and ending with the plate 16. All anchor elements 10 are recessed in monolithic sections 6 is empty from 5 plates. The corner 9 is installed so that the upper shelf 17 of the corner 9 is recessed in the upper part of the plate 18, and the end shelf 19 is recessed in the end part of the plate 20, and the lower edge 21 of the end shelf 19 of the corner 9 is located at the same level with the lower edge of the plate 22. Length the upper shelf 17 of the corner 9 of the embedded part 7 is always longer than the width of the supporting element 23 of the object under construction (see Fig. 1, 2, 3, 4).

The number of embedded parts 7 is determined by the structural need, depending on the design of adjacent prefabricated elements (floors, panels of external or internal walls) so that the total number of connections established through the considered embedded parts 7 is sufficient to ensure the stability of the building as a whole against progressive collapse in emergency situation.

An example implementation of the invention:

In the present invention can use multi-hollow floor slabs 1 - reinforced concrete prestressed bench formwork moldings up to 9.0 m long, intended for use in residential, public and industrial buildings with load-bearing walls made of bricks or blocks, as well as in frame, precast and monolithic prefabricated buildings erected under normal construction conditions. The indicated plates 1 are reinforced in the longitudinal direction in the lower zone (lower reinforced belt 3) with high-strength wire of class Bp1400 according to GOST 7348 with a diameter of 5 mm with a pitch of reinforcing beams of 120 mm and in the upper zone (upper reinforced belt 4) with single high-strength wires of class Bp1400 according to GOST 7348 with a diameter of 5 mm, transverse reinforcement is absent.

To increase the strength of butt joints with the proposed multi-hollow floor slabs, 1 ends of freshly formed slabs are reinforced in the factory by filling the voids with 5 concrete of class B25 to a length of 250 mm. This increases the strength of butt joints, making it possible to use multi-hollow floor slabs with 1 span of up to 6.6 m for large-panel buildings up to 25 floors. The estimated strength of the butt joints with the proposed multi-hollow floor slabs 1, which are sold in large-panel buildings, is confirmed by laboratory tests of JSC Research Center "Construction" in the structural unit of the NIIZhB named after A.A. Gvozdeva (Laboratory No. 2 Reinforced concrete structures and quality control. Contract No. 842 / 2-19-15 / ZhB from 08.24.2015).

Embedded parts 7 are made of steel equal-angle corner 140 * 140 * 9 in accordance with GOST 8509-93 80 mm wide and anchor rods for anchor elements 10 embedded parts 7. Before installing embedded parts 7 when molding multi-hollow floor slabs 1, on wet concrete, in the upper hollow sections of the slab make concrete cuts over each void 5 with a width of 80 mm and a length necessary for the formation of a monolithic section 6. Then the collapsed concrete is removed from the voids 5 and polystyrene caps are installed in the body of the slab 2 to prevent leakage concrete slabs inside. After that set the embedded parts 7 in accordance with the calculated parameters of the deepening. The voids 5 formed at the installation sites of embedded parts 7 are filled with high mobility concrete with a class of at least B25 and vibrated using a depth vibrator, thereby ensuring the formation of a monolithic section 6 connecting the embedded part 7 with the body of the plate 2.

The embedded part 7, installed on the end sections 8 of multi-hollow floor slabs 1, is designed with optimal dimensions of 140 × 80 × 200 mm for the possibility of installing voids 5 between the edges of the plates in the monolithic sections 6, taking into account the necessary anchoring for the perception of shear forces. The strength of the proposed embedded parts 7 in shear meets the requirements of GOST 8820-94 and is sufficient for the perception of shear forces in the nodes of large-panel buildings up to 25 floors.

The present invention can be implemented using elements of other perimeters.

The effectiveness of the proposed embedded parts is confirmed by laboratory tests of multi-hollow floor slabs with reinforced ends of JSC Research Center "Construction" in the structural unit of the NIIIZhB named after A.A. Gvozdeva (Laboratory No. 2 Reinforced concrete structures and quality control. Contract No. 229 / 2-7-16 / ZhB dated 10.03.2016).

The strength and reliability of butt joints with the proposed multi-hollow floor slab is achieved by redistributing the load on the monolithic sections and embedded parts that are longer than the supporting element of the building under construction.

All of the above indicates the fulfillment of the technical task, namely the creation of a multi-hollow floor slab, which ensures the strength of butt joints in multi-storey construction.

The list of positions:

1. Hollow core slab

2. Plate body

3. Lower reinforced belt

4. The upper reinforced belt

5. Void

6. Monolithic section

7. The embedded part

8. End section

9. Corner

10. Anchor elements

11. The inner side of the corner

12. The open part of the corner

13. Horizontal anchor element

14. Plate of horizontal anchor element

15. Vertical anchor element

16. Plate of vertical anchor element

17. The upper shelf of the corner

18. The top of the stove

19. End shelf corner

20. The end of the plate

21. The lower edge of the end flange of the corner

22. The bottom edge of the plate

23. Support element

Claims (1)

A multi-hollow floor slab containing the body of the slab, lower and upper reinforced belt and voids, characterized in that the multi-hollow floor slab is made with the formation in all voids of the end sections of the slab of the monolithic sections with embedded parts pre-installed in at least two voids, while the embedded parts are made in the form of a corner with anchor elements welded to the inside of the corner, turned with its open part with anchor elements into the body of the plate, and the corner has two horizontal anchor elements, which are connected at the free ends by a plate, and one vertical anchor element, passing between horizontal and ending with the plate, while all anchor elements are recessed in monolithic sections of the voids of the plate, and the corner is installed so that the upper shelf of the corner is recessed in the upper part of the plate, and the end shelf is buried in the end part of the plate, and the lower edge of the end shelf of the corner is located at the same level with the lower edge of the plate, while the length of the upper shelf of the corner of the mortgage d Details are always longer than the width of the supporting element of the building under construction.

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