Integral cast steel-concrete combined stair

Abstract

This utility model discloses a monolithically cast steel-concrete composite staircase. By replacing the conventional sawtooth side plate stair beams with rectangular steel pipe stair beams, and using U-shaped connectors to rigidly connect the concrete steps to the stair beams, a steel-concrete composite load-bearing system is formed, achieving uniform load transfer and enhancing overall rigidity and deformation resistance. At the same time, the distributed reinforcement and the main reinforcement are arranged crosswise and cast integrally, further optimizing the structural synergy and avoiding the stress concentration problem caused by the splicing of traditional precast steps.

Description

Technical Field

[0001] This utility model relates to the field of building structure technology, specifically to a monolithically cast steel-concrete composite staircase. Background Technology

[0002] Precast staircases, as prefabricated components, are widely used in new residential and office buildings. Common types of precast staircases include slab-type precast concrete staircases and steel staircases. While slab-type precast concrete staircases have lower material costs, they suffer from lower standardization, limited utilization of steel molds, high mold amortization costs, and are cumbersome to manufacture, heavy, and have high transportation and installation costs. Steel staircases, although lightweight, require a large amount of steel and necessitate anti-corrosion and fireproofing treatments. They also require secondary finishing, and the railings need to be welded to the steel staircase, making construction more complicated and resulting in a higher overall cost compared to precast concrete staircases. Utility Model Content

[0003] In view of the above-mentioned shortcomings of the existing technology, the purpose of this utility model is to provide an integrally cast steel-concrete composite staircase to solve the problems of low standardization, high production cost, heavy weight, high transportation and installation cost of existing precast concrete staircases, large steel consumption of steel staircases, need for anti-corrosion and fireproofing treatment, and need for secondary decoration.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] A monolithic cast-in-place steel-concrete composite staircase includes two opposing stair beams, the length of which extends vertically upwards or downwards. At each end of a stair beam is a fixing member, the length of which is perpendicular to the length of the stair beam, and both ends of the fixing member are fixedly connected to the two opposing stair beams. Multiple distribution and load-bearing reinforcing bars are laid between the two stair beams. The length of the distribution reinforcing bars is consistent with the length of the stair beams and is spaced along the length of the fixing members. One end of each distribution reinforcing bar is fixedly connected to one of the fixing members, and the other end is fixedly connected to the other fixing member. Load-bearing reinforcing bars are laid above the distribution reinforcing bars, and their length is perpendicular to the length of the distribution reinforcing bars and spaced along the length of the distribution reinforcing bars. Concrete is poured between the two stair beams to cover the distribution reinforcing bars, load-bearing reinforcing bars, and fixing members, forming concrete steps. The upper surface of each concrete step is stepped, and its lower surface is an upward or downward sloping surface.

[0006] Preferably, a plurality of connectors are provided on the ladder beam, the connectors being spaced apart along the length of the ladder beam; the connectors are U-shaped, with both ends of the connectors bent and extended in mutually opposite directions to form connecting ends; the connectors are located between two adjacent reinforcing bars, and the connecting ends of the connectors are fixedly attached to the ladder beam.

[0007] Preferably, the ladder beam is a rectangular steel pipe.

[0008] Preferably, a connecting box is provided at each end of the ladder beam. The connecting box is located on the opposite side of the two ladder beams and is fixedly connected to the ladder beams. The connecting box is a box-shaped structure with an opening on the top and an installation hole at its bottom, which penetrates through the bottom of the connecting box. A lifting hole is also provided on the side of the connecting box away from the ladder beam, which penetrates through the side wall of the connecting box.

[0009] Preferably, the fastener is L-shaped, and the outer side of one end of the fastener is fixedly connected to the outer side of the connecting box.

[0010] Compared with the prior art, the present invention has the following advantages:

[0011] 1. This utility model replaces the conventionally used sawtooth side plate ladder beams with rectangular steel pipe ladder beams, and uses U-shaped connectors to rigidly connect the concrete steps with the ladder beams, forming a steel-concrete composite stress system, realizing uniform load transfer and enhancing overall rigidity and deformation resistance; at the same time, the distribution reinforcement and the main reinforcement are arranged crosswise and cast as a whole, further optimizing the structural synergy and avoiding the stress concentration problem caused by the splicing of traditional precast steps.

[0012] 2. This utility model abandons the traditional prefabrication process of a single triangular step and adopts the whole step to be cast in one piece, which eliminates the need for step-by-step steel bar production, sleeve pre-embedding, block-by-block hardening and on-site assembly, simplifying the process by about 50% and significantly reducing labor costs and construction period; after casting, the steps are seamlessly connected, eliminating the need for secondary grouting and reducing on-site measures costs.

[0013] 3. This utility model combines the precise positioning design of U-shaped connectors and L-shaped fasteners to ensure reliable connection between the steel mesh and the ladder beam, thereby enhancing the structural durability under long-term use.

[0014] 4. This utility model provides connecting boxes with lifting holes and installation holes at both ends of the ladder beam, which facilitates modular lifting and rapid positioning installation, adapting to complex site conditions; the integral cast-in-place structure reduces the number of components, reduces transportation and storage difficulties, and provides a standardized solution for large-scale engineering applications. Attached Figure Description

[0015] Figure 1 This is a structural schematic diagram of a monolithically cast steel-concrete composite staircase according to the present invention.

[0016] Figure 2 for Figure 1 A magnified structural diagram of part A in the middle.

[0017] Figure 3This is a schematic diagram of the structure after the connecting box and the fastener are connected.

[0018] In the diagram: 1. Ladder beam; 2. Fixing component; 3. Distribution reinforcement; 4. Reinforcing reinforcement; 5. Concrete step; 6. Connecting component; 7. Connection box; 8. Mounting hole; 9. Lifting hole. Detailed Implementation

[0019] This utility model will be clearly and completely described with reference to the accompanying drawings of the embodiments of this utility model. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on this utility model are within the protection scope of this utility model.

[0020] To address the shortcomings of existing precast staircases, the applicant proposed a prefabricated steel-concrete composite staircase formed by connecting triangular precast concrete standard steps to steel ladder beams using embedded sleeves and bolts. Although this composite staircase reduces weight by 60% compared to slab concrete staircases, the applicant found several drawbacks in actual production and application: ① The connection to the ladder beams via embedded sleeves and bolts on the sides of the triangular steps suffers from poor overall integrity. ② The production process is complex, inefficient, and involves high labor costs. ③ The triangular steps exhibit poor forming quality and are prone to chipping and cracking on construction sites, affecting building quality. ④ Joints exist between each step, requiring additional treatment, increasing on-site construction procedures, construction time, and associated costs.

[0021] This utility model provides a monolithically cast steel-concrete composite staircase, such as... Figure 1-3As shown, the combined staircase includes two opposing stair beams 1, whose length direction extends vertically upwards or downwards. The stair beams are rectangular steel pipes. A fixing member 2 is provided at each end of the stair beam, the length direction of which is perpendicular to the length direction of the stair beam, and both ends of the fixing member are fixedly connected to the two opposing stair beams. Multiple distribution steel bars 3 and load-bearing steel bars 4 are laid between the two stair beams; the length direction of the distribution steel bars is consistent with the length direction of the stair beams and is spaced along the length direction of the fixing members; one end of each distribution steel bar is fixedly connected to one of the fixing members, and the other end is fixedly connected to the other fixing member; the load-bearing steel bars are laid above the distribution steel bars, and their length direction is perpendicular to the length direction of the distribution steel bars and is spaced along the length direction of the distribution steel bars, and the load-bearing steel bars are fixedly connected to the distribution steel bars by welding. Concrete is poured between the two stair beams to cover the distribution steel bars, load-bearing steel bars, and fixing members to form concrete steps 5; the upper surface of the concrete steps is stepped, and its lower surface is an upward or downward sloping surface. The distributed reinforcement and the main reinforcement are arranged in an intersecting manner and cast as a whole, which further optimizes the structural synergy and avoids the stress concentration problem caused by traditional precast step splicing.

[0022] In some embodiments of this utility model, multiple connecting members 6 are also provided on the ladder beam, such as... Figure 2 As shown, the connectors are spaced apart along the length of the ladder beam; each connector is U-shaped, with both ends bent and extended in opposite directions to form a connecting end; the connector is located between two adjacent reinforcing bars, and the connecting end is fixedly connected to the ladder beam. During the pouring of the concrete steps, by replacing the conventionally used sawtooth side plate ladder beams with rectangular steel pipe ladder beams and using U-shaped connectors to rigidly connect the concrete steps to the ladder beams, a steel-concrete composite load-bearing system is formed, achieving uniform load transfer. After actual construction, it was found that this significantly enhances the overall rigidity and deformation resistance.

[0023] In some embodiments of this utility model, a connecting box 7 is provided at each end of the ladder beam. The connecting box is located on one side opposite to the two ladder beams and is fixedly connected to them. The connecting box is a box-shaped structure with an opening at the top and a mounting hole 8 at its bottom, which penetrates the bottom of the connecting box. A lifting hole 9 is also provided on the side of the connecting box away from the ladder beam, penetrating the side wall of the connecting box. The design and use of the connecting box facilitates modular lifting and rapid positioning installation, adapting to complex site conditions.

[0024] In some embodiments of this utility model, the fixing member 2 is L-shaped, with the outer side of one end of the fixing member fixedly connected to the outer side of the connecting box, and the outer side of the other end located below the distributed reinforcing bars and fixedly connected to them.

[0025] During actual construction, the stair beams, fasteners, distributed reinforcing bars, load-bearing reinforcing bars, and connectors in this combined staircase can all be assembled in the factory through standardized production. The assembled steel structure is then transported to the construction site for installation and fixation before the concrete treads are poured. The overall cast-in-place structure reduces the number of components, lowers the difficulty of transportation and storage, and provides a standardized solution for large-scale engineering applications. At the same time, the addition of polypropylene fibers to the cast-in-place concrete can effectively enhance the tensile strength of the concrete, improve the molding quality, and effectively reduce the problems of concrete chipping and cracking.

[0026] This utility model is not limited to the above-described embodiments. Any structure that is the same as or similar to the above-described embodiments of this utility model is within the protection scope of this utility model.

[0027] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and not to limit the technical solutions. Those skilled in the art should understand that any modifications or equivalent substitutions to the technical solutions of this utility model that do not depart from the spirit and scope of this technical solution should be covered within the scope of the claims of this utility model.

Claims

1. A monolithically cast steel-concrete composite stair, characterized in that, It includes two opposing ladder beams (1), the length direction of which extends vertically upward or downward; a fixing member (2) is provided at each end of the ladder beam, the length direction of which is perpendicular to the length direction of the ladder beam, and the two ends of the fixing member are fixedly connected to the two opposing ladder beams respectively. Multiple distribution steel bars (3) and reinforcing steel bars (4) are laid between two ladder beams; the length direction of the distribution steel bars is consistent with the length direction of the ladder beams and is distributed at intervals along the length direction of the fixing members; one end of the distribution steel bar is fixedly connected to one of the fixing members and the other end is fixedly connected to another fixing member; the reinforcing steel bars are laid above the distribution steel bars, and the length direction of the reinforcing steel bars is perpendicular to the length direction of the distribution steel bars and is distributed at intervals along the length direction of the distribution steel bars. Concrete is poured between the two ladder beams to cover the distributed steel bars, the stressed steel bars and the fasteners to form concrete steps (5); the upper surface of the concrete steps is stepped and the lower surface is an upward or downward inclined surface.

2. The monolithically cast steel-concrete composite stair according to claim 1, characterized in that Multiple connectors (6) are also provided on the ladder beam, and the connectors are distributed at intervals along the length direction of the ladder beam; the connectors are U-shaped, and the two ends of the connectors are bent and extended in opposite directions to form connecting ends; the connectors are located between two adjacent reinforcing bars, and the connecting ends of the connectors are fixed to the ladder beam.

3. The monolithically cast steel-concrete composite stair according to claim 1, characterized in that The ladder beam is a rectangular steel pipe.

4. The monolithically cast steel-concrete composite stair of claim 1, wherein A connecting box (7) is provided at each end of the ladder beam. The connecting box is located on the opposite side of the two ladder beams and is fixedly connected to the ladder beams. The connecting box is a box-shaped structure with an opening on the top and an installation hole (8) is provided at its bottom. The installation hole penetrates the bottom of the connecting box. A lifting hole (9) is also provided on the side of the connecting box away from the ladder beam. The lifting hole penetrates the side wall of the connecting box.

5. The monolithically cast steel-concrete composite stair of claim 1, wherein The fastener is L-shaped, and the outer side of one end of the fastener is fixedly connected to the outer side of the connecting box.

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