A connecting reinforcing device for prefabricated stair

Abstract

The utility model discloses a prefabricated stair's connecting and reinforcing device belongs to prefabricated stair construction technical field, including the upper rest platform, the upper rest platform is fixed through the reinforcing steel bar in the lateral edge of wall body, and the lower end of the lateral edge of wall body is fixed with the lower rest platform through the reinforcing steel bar, and the upper end one side of upper rest platform and the upper end lateral edge of lower rest platform all are fixed with the embedded reinforcing steel bar through the mode of concrete embedding, the utility model discloses a steel pipe subassembly is set up, makes embedded reinforcing steel bar and contacts when inserting steel pipe inner wall, avoids reinforcing steel bar and concrete hole wall direct friction, thoroughly eliminates the hole mouth collapse edge, the corner phenomenon of falling, guarantees the step end face complete, improves the grouting body grip and node durability, the utility model discloses a buffer pad is set up, and the elastic transition is formed between the platform step and the rest platform, can absorb crowd walking and the vertical impact under the action of earthquake, reduces the stress concentration of step end, prevents the microcrack and the hollow, promotes the use comfort and the structure life.

Description

Technical Field

[0001] This utility model belongs to the field of prefabricated staircase construction technology, specifically relating to a connection and reinforcement device for prefabricated staircases. Background Technology

[0002] Precast stairs refer to a modular staircase solution where reinforced concrete stair sections (including treads, risers, and inclined beams) are cast as a whole in a factory, cured to the design strength, and then transported to the construction site for direct hoisting and installation. Compared with cast-in-place stairs, precast stairs have advantages such as faster construction speed, less on-site wet work, better molding quality, and higher dimensional accuracy. They can significantly shorten the construction period and reduce labor and formwork costs, and have become an indispensable standardized component in prefabricated residential and public buildings.

[0003] However, in actual engineering, it was found that the above-mentioned conventional device still has two defects: First, the reinforcing bars are directly inserted through the reserved concrete insertion holes, and there is no isolation layer between the hole wall and the reinforcing bars. During the installation process, the reinforcing bars and the concrete hole wall will rub against each other, which will easily crush and chip the edge of the hole, weakening the bonding force of the grout later. Second, the joint between the stairs and the platform is filled only by rigid grout, which lacks vertical deformation margin after forming a rigid node. When pedestrian traffic or horizontal earthquake action occurs, instantaneous stress concentration is likely to occur at the end of the step, resulting in micro-cracks or even surface hollowing, affecting the comfort and durability of use. Utility Model Content

[0004] To address the problems mentioned in the background section, this utility model provides a connection and reinforcement device for prefabricated stairs, which can prevent the hole walls from chipping and corners from breaking after the prefabricated stairs are installed, and improves the overall stability and durability of the prefabricated stairs after installation.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a connection and reinforcement device for a prefabricated staircase, comprising an upper resting platform, which is fixed to the side of a wall by steel bars, and a lower resting platform is fixed to the lower end of the side of the wall by steel bars. Pre-embedded steel bars are fixed to the upper side of both the upper and lower resting platforms by concrete embedding. A prefabricated staircase body is installed at the upper end of the upper and lower resting platforms. Platform steps are provided at both the upper and lower ends of the prefabricated staircase body, and steel pipe assemblies corresponding to the pre-embedded steel bars are installed inside the platform steps.

[0006] Preferably, the wall has several anchoring steel bars pre-embedded at the elevation of the upper rest platform. The anchoring steel bars extend into the cast-in-place layer of the upper rest platform and are tied with the platform's load-bearing steel bars before being poured with concrete in one go, so as to achieve a rigid connection between the wall and the upper rest platform.

[0007] Preferably, four sets of hanging nails are fixed inside the upper end of the prefabricated staircase body by pre-embedding in concrete. The upper end of the hanging nail is provided with a hanging ring, the lower end of the hanging ring is provided with a bolt, and the interior of the hanging nail is provided with a screw hole corresponding to the bolt.

[0008] Preferably, a buffer pad is provided on the upper side of the resting platform at the edge of the installation position of the platform step.

[0009] Preferably, the steel pipe assembly includes a steel pipe, with a corresponding pre-embedded steel bar embedded inside the platform step, and a limiting groove for the corresponding steel pipe is opened inside the platform step.

[0010] Preferably, the steel pipe assembly further includes a limiting ring, the surface of the steel pipe is provided with a limiting ring, and the interior of the mounting hole is provided with a limiting groove corresponding to the limiting ring.

[0011] Preferably, the prefabricated staircase body has multiple sets of side positioning grooves on its side, and multiple sets of side embedded steel plates are fixed on the side of the wall corresponding to the positions of the side positioning grooves.

[0012] Compared with the prior art, the beneficial effects of this utility model are:

[0013] 1. This utility model, by setting up a steel pipe assembly, allows the pre-embedded reinforcing bars to contact the inner wall of the steel pipe when inserted, avoiding direct friction between the reinforcing bars and the concrete hole wall, completely eliminating the phenomenon of edge chipping and corner breaking at the hole opening, ensuring the integrity of the step end face, and improving the grout bonding force and joint durability.

[0014] 2. This utility model, by setting a buffer pad, forms an elastic transition between the platform step and the resting platform, which can absorb the vertical impact of people walking and earthquakes, reduce stress concentration at the end of the steps, prevent micro-cracks and hollows, and improve user comfort and structural life. Attached Figure Description

[0015] Figure 1 This is a perspective view of the present utility model;

[0016] Figure 2 This is a three-dimensional view of the prefabricated staircase installation process according to this utility model;

[0017] Figure 3 This utility model Figure 1 Enlarged view of point A in the middle;

[0018] Figure 4 This is a perspective view of the prefabricated staircase of this utility model;

[0019] Figure 5 This utility model Figure 4 Enlarged view of the steel pipe assembly;

[0020] In the diagram: 1. Wall; 2. Upper rest platform; 3. Platform steps; 4. Precast staircase main body; 5. Steel pipe assembly; 51. Limiting ring; 52. Steel pipe; 53. Limiting groove; 54. Mounting hole; 6. Embedded steel bar; 7. Buffer pad; 8. Lower rest platform; 9. Side positioning groove; 10. Side embedded steel plate; 11. Lifting ring; 12. Bolt; 13. Lifting nail; 14. Screw hole. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] Example 1

[0023] Please see Figure 1-5 The present invention provides the following technical solution: a connection and reinforcement device for a prefabricated staircase, including an upper rest platform 2, which is fixed to the side of a wall 1 by steel bars. A lower rest platform 8 is fixed to the lower end of the side of the wall 1 by steel bars. Pre-embedded steel bars 6 are fixed to the upper side of the upper rest platform 2 and the upper side of the lower rest platform 8 by concrete pre-embedding. A prefabricated staircase body 4 is installed at the upper end of the upper rest platform 2 and the lower rest platform 8. Platform steps 3 are provided at both the upper and lower ends of the prefabricated staircase body 4. Steel pipe assemblies 5 corresponding to the pre-embedded steel bars 6 are provided inside the platform steps 3.

[0024] Specifically, several anchoring steel bars are pre-embedded in wall 1 at the elevation of the upper rest platform 2. The anchoring steel bars extend into the cast-in-place layer of the upper rest platform 2 and are tied to the platform's load-bearing steel bars before concrete is poured in one go to achieve a rigid connection between wall 1 and the upper rest platform 2.

[0025] By adopting the above technical solution, the platform and wall 1 form an integral node, which can bear the combined forces of tension, compression and shear under seismic action, avoiding the slippage risk caused by traditional post-anchoring.

[0026] Specifically, four sets of hanging nails 13 are fixed inside the upper end of the precast staircase body 4 by pre-embedding in concrete. The upper end of the hanging nail 13 is provided with a hanging ring 11, and the lower end of the hanging ring 11 is provided with a bolt 12. The interior of the hanging nail 13 is provided with screw holes 14 corresponding to the bolts 12.

[0027] By adopting the above technical solution, during the hoisting stage, it is only necessary to screw the lifting ring 11 into the lifting nail 13 to form a four-point lifting. After the hoisting is completed, the lifting ring 11 and the lifting nail 13 are removed and the removed holes are sealed with mortar of the same strength to ensure that the surface is flat and leaves no hidden dangers.

[0028] Specifically, a cushioning pad 7 is provided at the edge of the upper side of the rest platform 2, corresponding to the installation position of the platform step 3.

[0029] By adopting the above technical solution, the buffer pad 7 is made of 10mm thick neoprene rubber sheet, with a width flush with the front edge of the step. It can absorb the vertical impact energy of pedestrians and earthquakes, and reduce the incidence of cracks at the ends of the steps.

[0030] In this embodiment, the cast-in-place corbel, i.e., the upper and lower rest platforms, is first leveled with M20 cement mortar, with a thickness controlled at 15-25mm. Galvanized steel leveling shims are added where the local elevation deviation is >5mm to ensure uniform contact between the bottom surface of platform step 3 and the platform surface. After the leveling layer strength is ≥20MPa, the precast staircase body 4 is slowly lowered into place, so that the embedded steel bars 6 are inserted into the inner cavity of the steel pipe 52, and the side positioning groove 9 is finely adjusted with a rubber hammer to align with the side embedded steel plate 10. After the staircase is lowered into place, the temporary fixing nuts are tightened immediately, and then the horizontal gap between the steps and the platform is sealed with a flexible polyethylene rod with a gap width of 10-15mm, leaving only the top grouting port. Pressure grouting with non-shrink grout with a compressive strength ≥60MPa is used until grout continuously overflows from the outlet. After curing for 24 hours, the sealing rod is removed and the surface is cleaned.

[0031] Example 2

[0032] The difference between this embodiment and embodiment 1 is that: the steel pipe assembly 5 includes a steel pipe 52, the platform step 3 has a steel pipe 52 pre-embedded with a corresponding pre-embedded reinforcing bar 6, and the platform step 3 has a limiting groove 53 corresponding to the steel pipe 52.

[0033] By adopting the above technical solution, the inner wall of the steel pipe 52 is shot blasted to remove rust and coated with epoxy zinc-rich primer, which reduces the friction coefficient by 30% and can effectively prevent edge chipping when inserting reinforcement bars; the limiting groove 53 is 3mm deep and forms an embedded positioning with the limiting ring 51 to ensure that the steel pipe 52 does not shift during concrete vibration.

[0034] Specifically, the steel pipe assembly 5 also includes a limiting ring 51. The surface of the steel pipe 52 is provided with the limiting ring 51, and the mounting hole 54 has a limiting groove 53 corresponding to the limiting ring 51 inside.

[0035] By adopting the above technical solution, the limiting ring 51 and the steel pipe 52 are connected by a double-sided fillet weld with a weld height of 6mm, which can withstand a pull-out force of ≥5kN, ensuring that the steel pipe 52 does not sink or rotate before grouting.

[0036] Specifically, multiple sets of side positioning grooves 9 are opened on the side of the prefabricated staircase body 4, and multiple sets of side embedded steel plates 10 are fixed on the side of the wall 1 corresponding to the positions of the side positioning grooves 9.

[0037] By adopting the above technical solution, the side positioning groove 9 is 20mm deep and filled with grout of the same strength to form an additional shear key, which can bear 15% of the horizontal seismic force of the staircase and reduce the burden on the main connection node.

[0038] In this embodiment, the side-embedded steel plate 10 is installed during the cast-in-place stage of the wall 1, with the plate surface flush with the wall surface. Before installation, the laitance is removed and an interface agent is applied. After the staircase is in place, the 5mm gap between the side positioning groove 9 and the side-embedded steel plate 10 is filled with flexible foam strips to prevent grout from overflowing. After the main joint of the staircase is grouted and the strength reaches 30MPa, a second grouting is injected into the side positioning groove 9 to form a hidden shear key. Finally, the surface is smoothed with the same grade of mortar to achieve a fair-faced finish without exposed metal parts.

[0039] The working principle and usage process of this utility model are as follows: When using this utility model, the prefabricated staircase body 4, steel pipe assembly 5, hanging nails 13 and side positioning groove 9 are first cast in the factory; on site, the wall 1 and the upper and lower rest platforms 2 and 8 are cast simultaneously, and the pre-embedded steel bars 6, side pre-embedded steel plates 10 and anchoring steel bars are accurately embedded; during the hoisting stage, the staircase is lifted at four points by the lifting rings 11, and after being placed, it is quickly installed by relying on the joint of the steel pipe 52 and the pre-embedded steel bars 6, the self-positioning of the limiting ring 51 and the limiting groove 53, and the shear key of the side positioning groove 9 and the side pre-embedded steel plate 10; then, the impact is absorbed by the buffer pad 7, the gaps are sealed by flexible materials, and the joints are filled with high-strength grout, finally forming a "rigid + tough" composite connection to meet the requirements of seismic resistance and durability.

[0040] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A connection and reinforcement device for a prefabricated staircase, comprising an upper resting platform (2), wherein the upper resting platform (2) is fixed to the side of a wall (1) by steel bars, and a lower resting platform (8) is fixed to the lower end of the side of the wall (1) by steel bars, and embedded steel bars (6) are fixed to the upper side of the upper resting platform (2) and the upper side of the lower resting platform (8) by pre-embedding in concrete, characterized in that: The upper rest platform (2) and the lower rest platform (8) are equipped with prefabricated stair body (4). Platform steps (3) are set at both the upper and lower ends of the prefabricated stair body (4). Steel pipe components (5) with corresponding pre-embedded steel bars (6) are set inside the platform steps (3).

2. The connection and reinforcement device for a prefabricated staircase according to claim 1, characterized in that: The wall (1) has several anchoring steel bars pre-embedded at the elevation position of the upper rest platform (2). The anchoring steel bars extend into the cast-in-place layer of the upper rest platform (2) and are tied with the platform's load-bearing steel bars before being poured into concrete in one go, so as to achieve a rigid connection between the wall (1) and the upper rest platform (2).

3. The connection and reinforcement device for a prefabricated staircase according to claim 1, characterized in that: The upper part of the prefabricated staircase body (4) is fixed with four sets of hanging nails (13) by pre-embedding concrete. The upper end of the hanging nail (13) is provided with a hanging ring (11), and the lower end of the hanging ring (11) is provided with a bolt (12). The interior of the hanging nail (13) is provided with screw holes (14) corresponding to the bolts (12).

4. The connection and reinforcement device for a prefabricated staircase according to claim 1, characterized in that: A buffer pad (7) is provided on the upper side of the resting platform (2) at the edge of the installation position of the platform step (3).

5. The connection and reinforcement device for a prefabricated staircase according to claim 1, characterized in that: The steel pipe assembly (5) includes a steel pipe (52), and the platform step (3) has a steel pipe (52) with a corresponding pre-embedded steel bar (6) embedded inside, and a limiting groove (53) corresponding to the steel pipe (52) is opened inside the platform step (3).

6. The connection and reinforcement device for a prefabricated staircase according to claim 5, characterized in that: The steel pipe assembly (5) also includes a limiting ring (51), the surface of the steel pipe (52) is provided with a limiting ring (51), and the interior of the mounting hole (54) is provided with a limiting groove (53) corresponding to the limiting ring (51).

7. The connection and reinforcement device for a prefabricated staircase according to claim 1, characterized in that: The prefabricated staircase body (4) has multiple sets of side positioning grooves (9) on its side, and multiple sets of side embedded steel plates (10) are fixed on the side of the wall (1) corresponding to the positions of the side positioning grooves (9).

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