Lightweight prefabricated concrete stair and preparation mold thereof

Abstract

The utility model discloses a kind of lightweight precast concrete staircases and preparation mould thereof, including stair body, multiple steps are equipped on the upside surface of stair body, form step;Two ladder beams stress reinforcements are respectively arranged in the inside of stair body and along the two sides of stair body width direction, one of ladder beams stress reinforcement is located in the side close to stair layer upper surface, another ladder beams stress reinforcement is located in the side close to stair layer lower surface, and two ends of one of ladder beams stress reinforcement are fixedly connected with the two ends of another ladder beams stress reinforcement located below it;Step stress reinforcement is laid in each step, and two ends of step stress reinforcement are respectively bent towards the direction of ladder beams stress reinforcement, and fixedly connected with ladder beams stress reinforcement;Multiple step distribution steels are laid below step stress reinforcement, and the length direction of step distribution steel is perpendicular to the length direction of step stress reinforcement, and fixedly connected with step stress reinforcement.

Description

Technical Field

[0001] This utility model relates to the field of building structure technology, specifically to a lightweight precast concrete staircase and its preparation mold. Background Technology

[0002] Precast concrete slab staircases are widely used in residential buildings as prefabricated components. However, precast concrete slab staircases require a large amount of material, are heavy, and have high transportation and hoisting costs. Sometimes, to meet the requirements of on-site tower crane lifting capacity, the staircase has to be produced in two parts separately. This causes inconvenience to factory production, on-site installation, and subsequent decoration, increases the number of processes, consumes more labor, and results in high overall costs. Utility Model Content

[0003] In view of the above-mentioned shortcomings of the existing technology, the purpose of this utility model is to provide a prefabricated lightweight concrete staircase and its preparation mold, so as to solve the problems of large material consumption, heavy weight, and high transportation and hoisting costs of prefabricated concrete slab staircases in the existing technology.

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

[0005] A lightweight precast concrete staircase includes a staircase body with multiple steps forming a staircase on its upper surface. Two reinforcing bars are installed on both sides of the staircase body along its width. One reinforcing bar is located near the upper surface of the staircase step, and the other is located near the lower surface of the staircase step. Both ends of one reinforcing bar are fixedly connected to the ends of the other reinforcing bar located below it. Each step has a reinforcing bar, with both ends bent towards the reinforcing bars and fixedly connected to them. Multiple distribution reinforcing bars are installed below the reinforcing bars, their lengths perpendicular to the reinforcing bars and fixedly connected to them.

[0006] Preferably, one end of the reinforcing bar of the ladder beam is bent toward the other end of the reinforcing bar and continues to extend along the length of the reinforcing bar to form a U-shaped connecting end I; the other end of the reinforcing bar of the ladder beam is bent and continues to extend to form a connecting end II, such that the length direction of the connecting end II forms an angle with the length direction of the reinforcing bar of the ladder beam; among two adjacent reinforcing bars of the ladder beam, the connecting end I of one reinforcing bar of the ladder beam is fixedly connected to the connecting end II of the other reinforcing bar of the ladder beam.

[0007] Preferably, concrete ladder beams are provided on both sides of the concrete layer along its length, and the force is borne within the concrete ladder beams.

[0008] Preferably, a connecting section is provided at both ends of the concrete layer along its length; multiple reinforcing bars are provided in the connecting section, the reinforcing bars are arranged along the width direction of the step, and the reinforcing bars are distributed in the upper and lower layers of the connecting section; multiple reinforcing stirrups are sleeved outside the upper and lower layers of reinforcing bars, the reinforcing stirrups are spaced apart along the length direction of the reinforcing bars.

[0009] This utility model also provides a mold for preparing the above-mentioned concrete stairs. The mold includes a side mold I, a side mold II, and a mold base. The side mold I and the side mold II are arranged opposite to each other and are located on both sides of the mold base along its length. The side mold I and the side mold II are detachably and fixedly connected to the mold base. The surface of the side mold II facing the side mold I is stepped. End sealing plates are provided at both ends of the side mold I along its length, and the end sealing plates are fixedly connected to the side mold I and the side mold II, so that the side mold I, the side mold II, the mold base, and the end sealing plates enclose and form a mold cavity.

[0010] Preferably, a boss is formed in the middle of the side surface of side mold I facing side mold II, so that the edge of the side surface of side mold I facing side mold II forms a boss side; multiple fixing holes are provided on the boss side of side mold I, and the fixing holes are provided one-to-one with the two ends of the step reinforcing steel bars, so that the two ends of the step reinforcing steel bars can be inserted into the fixing holes, thereby fixing the step reinforcing steel bars in the mold cavity.

[0011] Preferably, the mold base has multiple support frames on the side opposite to the side mold I, and the support frames are distributed at intervals along the mold base to support the mold.

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] 1. This utility model optimizes the force transmission path of the staircase, that is, the steps transfer the vertical load to the two side stair beams, and then to the supports at both ends of the stair beams. This significantly reduces the amount of concrete and steel bars used, directly reduces the self-weight and saves material costs. At the same time, it facilitates transportation and hoisting, thus reducing the overall cost.

[0014] 2. Compared with slab stairs, the stairs described in this utility model have a 40% to 50% reduction in weight. The significant reduction in weight allows the stairs to be cast in one piece, solving the problems of production, installation, and subsequent decoration troubles caused by the need to divide precast concrete slab stairs into two parts due to their heavy weight and insufficient on-site tower crane lifting capacity.

[0015] 3. This utility model provides a mold for preparing the lightweight precast concrete staircase. The mold accurately positions the reinforcing steel bars of the steps through the fixing holes, so that the protective layer of the produced staircase components is of uniform thickness and the position of the reinforcing steel bars is accurate and reliable, which greatly improves the product quality and structural reliability. Attached Figure Description

[0016] Figure 1 This is a structural schematic diagram of the lightweight precast concrete staircase described in this utility model.

[0017] Figure 2 This is a schematic diagram of the structure after the reinforcement bars of the ladder beam and the reinforcement bars of the steps are installed.

[0018] Figure 3 This is a structural schematic diagram of the reinforcing bars and stirrups in the connecting section.

[0019] Figure 4 This is a structural diagram illustrating one of the connection methods between the connecting section and the main building.

[0020] Figure 5 This is a structural schematic diagram of the reinforcing steel bars in a ladder beam.

[0021] Figure 6 This is a structural diagram showing the locations of the concrete stair beams, mounting holes, and hoisting holes in the staircase body.

[0022] Figure 7 This is a schematic diagram of the structure after the mold base and side mold I are installed.

[0023] Figure 8 This is a schematic diagram of the structure after the side mold I, side mold II, mold base and end sealing plate are enclosed.

[0024] Figure 9 A schematic diagram of the structure in which the reinforcing steel bars of the steps are fixed in the mold before concrete pouring.

[0025] In the diagram: 1. Staircase body; 2. Steps; 3. Stair beam reinforcing bars; 4. Step reinforcing bars; 5. Connection end I; 6. Connection end II; 7. Concrete stair beam; 8. Connection section; 9. Reinforcing bars; 10. Side formwork I; 11. Side formwork II; 12. Mold base; 13. End sealing plate; 14. Boss; 15. Boss side; 16. Mounting hole; 18. Mounting platform; 19. Mounting plate; 20. L-shaped connecting bolt; 21. Mounting nut; 22. Step distribution reinforcing bars; 23. Lifting hole; 24. Detailed Implementation

[0026] 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.

[0027] I. A lightweight precast concrete staircase

[0028] The precast concrete building includes a staircase body 1, such as... Figure 1 and 6 As shown, multiple steps 2 are provided on the upper surface of the staircase body. These steps are evenly spaced and inclined downwards or upwards in the vertical direction, forming steps. Two reinforcing steel bars 3 are respectively installed on both sides of the staircase body along its width. One reinforcing steel bar is located near the upper surface of the staircase body, and the other is located near the lower surface. Both ends of one reinforcing steel bar are fixedly connected to the ends of the other reinforcing steel bar located below it. Each step is provided with reinforcing steel bars 4, such as... Figure 2 As shown, the two ends of the step reinforcing bars are bent toward the direction of the ladder beam reinforcing bars and are fixedly connected to the ladder beam reinforcing bars. The step reinforcing bars 4 transfer the vertical load of the step to the ladder beams on both sides, and the ladder beams then transfer the load to the supports. This changes the way the slab staircase transfers the load to both ends of the supports. This force transfer method is more reasonable and reduces the amount of material used. Multiple step distribution reinforcing bars are laid below the step reinforcing bars. The length direction of the step distribution reinforcing bars is perpendicular to the length direction of the step reinforcing bars and is fixedly connected to the step reinforcing bars.

[0029] To address the shortcomings of existing precast staircases, the inventor proposed two types of steel-concrete composite staircases. The first type is an assembled steel-concrete composite staircase formed by connecting triangular precast concrete standard steps to steel ladder beams using pre-embedded sleeves and bolts. Although this type of composite staircase reduces its weight by 60% compared to slab concrete staircases, the inventor found that it still has shortcomings in actual production and application, mainly: ① The connection of the ladder beams on the sides of the triangular steps using pre-embedded sleeves and bolts results in poor overall integrity. ② The production process is complex, with low production efficiency and high labor costs. ③ The triangular steps have poor forming quality and are prone to corner chipping and cracking on the construction site, affecting the building quality. ④ There are splicing seams between each step, requiring additional treatment, increasing on-site construction procedures, construction period, and costs. The second type replaces the sawtooth steel ladder beams of the first type with rectangular tube ladder beams. The ladder beams are placed below the steps, and π-shaped steel bars are welded to the upper flange of the rectangular tube ladder beams and tied with steel mesh. Then, the steps are poured integrally, with the π-shaped steel bars acting as shear-resistant connectors. Although the second type of steel-concrete composite staircase is superior to the first in terms of material usage, overall integrity, and production efficiency, it still has shortcomings: ① The material usage of the rectangular tube steel stair beams is not economical enough and can be further optimized. ② The welding of steel structure steel and reinforcing bars still exists; the fabrication of π-shaped reinforcing bars is troublesome, inconvenient to position on the rectangular tube beams, and requires a large amount of welding. ③ Since the rectangular tubes are directly exposed to the air, additional anti-corrosion and fireproofing treatments are required, increasing later maintenance costs.

[0030] Based on this, this utility model has been further improved by replacing the rectangular tube stair beam with a concrete stair beam. The design focuses on optimizing the steel reinforcement structure, setting two appropriately positioned reinforcing bars for the stair beam, with both ends fixedly connected. Simultaneously, the ends of the reinforcing bars for the steps are fixed to the reinforcing bars for the stair beam, and the distributed reinforcing bars for the steps are perpendicularly fixed to the reinforcing bars for the steps, forming a more rational steel reinforcement skeleton. This ensures structural strength while achieving lightweight design, avoids the need for anti-corrosion and fireproofing treatments, and reduces later maintenance costs. The optimized steel reinforcement structure makes the staircase more rationally stressed, significantly improving structural strength and durability. During long-term use, it can better withstand loads, reducing the need for maintenance or even replacement, and extending the lifespan of the staircase. The lightweight design of the staircase not only reduces transportation costs and energy consumption during transportation, but also lowers the requirements for lifting equipment during installation, significantly improving installation efficiency and potentially enabling more flexible installation methods. Meanwhile, using specially designed molds, the entire lightweight precast concrete staircase can be poured in one go, eliminating the need for steel structure welding and improving production efficiency. The joints between adjacent steps are chamfered, reducing concrete thickness while still meeting the required protective layer thickness for the reinforcing steel. During actual construction, polypropylene fibers are added to the cast-in-place concrete, effectively enhancing its tensile strength, resulting in better molding quality and reducing issues such as corner chipping and cracking.

[0031] In some embodiments of this utility model, such as Figure 5 As shown, one end of the reinforcing bar of the ladder beam is bent towards the other end of the reinforcing bar and continues to extend along the length of the reinforcing bar to form a U-shaped connecting end I 5; the other end of the reinforcing bar is bent and continues to extend to form a connecting end II 6, such that the length direction of the connecting end II forms an angle with the length direction of the reinforcing bar, and the angle is less than 90°, preferably 45°; among two adjacent reinforcing bars of the ladder beam, the connecting end I of one reinforcing bar is fixedly connected to the connecting end II of the other reinforcing bar.

[0032] In some embodiments of this utility model, such as Figure 2 As shown, concrete stair beams 7 are formed by vertically protruding downwards on the lower surfaces of the two sides of the stair body along its width direction, and the reinforcing steel bars of the stair beams are located inside the concrete stair beams.

[0033] In some embodiments of this utility model, to avoid obscuring the load-bearing steel bars of the ladder beam and causing unclear display, Figure 3 Only the structure of the connecting section is shown; the reinforcing steel bars of the ladder beam are omitted. For example... Figure 3 As shown, connecting sections 8 are provided at both ends of the staircase along its length; multiple reinforcing bars 9 are provided in the connecting sections, the reinforcing bars are arranged along the width of the steps, and the reinforcing bars are distributed in the upper and lower layers of the connecting sections; multiple reinforcing stirrups 10 are sleeved outside the upper and lower layers of reinforcing bars, the reinforcing stirrups are distributed at intervals along the length of the reinforcing bars.

[0034] Similarly, in some embodiments of this utility model, such as Figure 4 As shown, multiple mounting holes 18 are provided on the connecting section, extending through the upper and lower sides of the connecting section. At the lower vertical end of the staircase, the side wall of one of the mounting holes, facing away from the main building, protrudes inward to form a mounting platform 19. A mounting plate 20 is provided on the mounting platform, fixedly connected to it, and has through holes. Meanwhile, an L-shaped connecting screw 21 is provided at the location where the main building connects to the staircase. One end of the L-shaped connecting screw is embedded in the main building, and the other end extends out of the main building, into the mounting hole, and through the through hole on the mounting plate. A mounting nut 22 is fitted onto the other end of the L-shaped connecting screw to achieve a sliding connection, so that the staircase is not involved in the overall structural seismic calculation. At the upper vertical end of the staircase, a mounting hole and an L-shaped connecting screw are also provided. Here, one end of the L-shaped connecting screw is embedded in the main building, and the other end extends out of the main building and continues into the mounting hole. Concrete is then poured into the mounting hole for anchoring, so that the upper end of the staircase is fixedly connected to the main building.

[0035] In some embodiments of this utility model, such as Figure 6 As shown, multiple hoisting holes 24 are also provided on the connecting section for hoisting the stairs.

[0036] II. A mold for preparing the above-mentioned concrete staircase

[0037] like Figure 7-8 As shown, the mold includes side mold I 11, side mold II 12 and mold base 13. Side mold I and side mold II are arranged opposite to each other and are located on both sides of the mold base along its length direction. Side mold I and side mold II are detachably and fixedly connected to the mold base. The surface of side mold II facing side mold I is stepped. End sealing plates 14 are provided at both ends of side mold I along its length direction and are fixedly connected to side mold I and side mold II respectively, so that side mold I, side mold II, mold base and end sealing plates enclose and form a mold cavity.

[0038] In the fabrication of concrete stairs, it was found that precise positioning of the reinforcing steel reinforcement cage within the mold is a challenge in traditional precast stair production, especially when there are complex tread reinforcements. Reinforcing steel displacement leads to uneven concrete cover thickness, affecting structural durability and load-bearing performance. To address this, this invention designs a mold that incorporates multiple fixing holes on side mold I, such as... Figure 9 As shown, the fixing bolt 24 passes through the fixing hole from the outside of the mold, with its end facing away from the fixing hole extending into the mold. A flexible washer 25 is then placed on the end of the fixing bolt 24 that extends into the mold. Next, a sleeve 26 is threaded onto the end of the fixing bolt 24 that extends into the mold and the sleeve 26 is tightened. Finally, the step-bearing reinforcing bar 4 is tied and fixed to the sleeve 26. This method can fix the step-bearing reinforcing bar 4 onto the mold. This ensures the positional accuracy of the reinforcing bar and allows the thickness of the protective layer to be determined based on the length of the fixing bolt, fundamentally solving the problems of inaccurate positioning and difficulty in controlling the protective layer.

[0039] In some embodiments of this utility model, a boss 15 is formed in the middle of the side surface of side mold I facing side mold II in the direction of side mold II, and a boss side 16 is formed on the edge of the side surface of side mold I facing side mold II; a plurality of fixing holes are provided on the boss side of side mold I, and the fixing holes are provided one-to-one with the two ends of the step force reinforcing steel bars, so that the two ends of the step force reinforcing steel bars can be inserted into the fixing holes, thereby fixing the step force reinforcing steel bars in the mold cavity.

[0040] In some embodiments of this utility model, a plurality of support frames 17 are provided on the side of the mold base away from the side mold I. The support frames are distributed at intervals along the mold base to support the mold.

[0041] Construction process: First, fix the reinforcing steel bars of the steps to the side formwork I using fixing bolts; then, tie and fix the reinforcing steel bars of the ladder beams and the distributed reinforcing steel bars of the steps to the reinforcing steel bars of the steps respectively; then, assemble side formwork I, side formwork II, and the formwork base. The assembled formwork is as follows: Figure 8 As shown; then, concrete with added polypropylene fibers is poured into the mold cavity, and after solidification, the staircase is obtained. The staircase is transported to the site and hoisted to the construction location to complete the on-site installation.

[0042] 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.

[0043] 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 lightweight precast concrete staircase, comprising a staircase body (1), wherein a plurality of steps (2) are provided on the upper surface of the staircase body to form a staircase; characterized in that, Two reinforcing bars for the ladder beam are respectively installed on both sides of the ladder body along the width direction of the ladder body (3). One reinforcing bar for the ladder beam is located on the side close to the upper surface of the ladder layer, and the other reinforcing bar for the ladder beam is located on the side close to the lower surface of the ladder layer. The two ends of one reinforcing bar for the ladder beam are respectively fixedly connected to the two ends of the other reinforcing bar for the ladder beam located below it. Each step is provided with step reinforcing steel bars (4), the two ends of which are bent toward the direction of the ladder beam reinforcing steel bars and are fixedly connected to the ladder beam reinforcing steel bars; multiple step distribution steel bars (23) are provided below the step reinforcing steel bars, the length direction of which is perpendicular to the length direction of the step reinforcing steel bars and is fixedly connected to the step reinforcing steel bars.

2. The lightweight precast concrete staircase according to claim 1, characterized in that, One end of the reinforcing bar of the ladder beam is bent toward the other end of the reinforcing bar and continues to extend along the length of the reinforcing bar to form a U-shaped connecting end I (5); the other end of the reinforcing bar of the ladder beam is bent and continues to extend to form a connecting end II (6), so that the length of the connecting end II forms an angle with the length of the reinforcing bar of the ladder beam; among two adjacent reinforcing bars of the ladder beam, the connecting end I of one reinforcing bar of the ladder beam is fixedly connected to the connecting end II of the other reinforcing bar of the ladder beam.

3. The lightweight precast concrete staircase according to claim 1, characterized in that, The staircase body has concrete stair beams (7) on both sides along its width direction, and the reinforcing steel bars of the stair beams are located inside the concrete stair beams.

4. The lightweight precast concrete staircase according to claim 1, characterized in that, Connecting sections (8) are provided at both ends of the staircase along its length; multiple reinforcing bars (9) are provided in the connecting sections, the reinforcing bars are arranged along the width of the steps, and the reinforcing bars are distributed in the upper and lower layers of the connecting sections; multiple reinforcing stirrups (10) are provided outside the upper and lower layers of reinforcing bars, the reinforcing stirrups are distributed at intervals along the length of the reinforcing bars.

5. A mold for preparing the concrete staircase according to any one of claims 1-4, characterized in that, The mold includes side mold I (11), side mold II (12) and mold base (13). Side mold I and side mold II are arranged opposite to each other and are located on both sides of the mold base along its length. Side mold I and side mold II are detachably and fixedly connected to the mold base. The side surface of side mold II facing side mold I is stepped. End sealing plates (14) are provided at both ends of side mold I along its length, and the end sealing plates are fixedly connected to side mold I and side mold II respectively, so that side mold I, side mold II, mold base and end sealing plates enclose and form a mold cavity.

6. The mold according to claim 5, characterized in that, A boss (15) is formed in the middle of the side surface of side mold I facing side mold II, so that the edge of the side surface of side mold I facing side mold II forms a boss side (16); multiple fixing holes are provided on the boss side of side mold I, and the fixing holes fix the step force-bearing steel bars in the mold cavity.

7. The mold according to claim 5, characterized in that, The mold base is provided with multiple support frames (17) on the side away from the side mold I. The support frames are distributed at intervals along the mold base to support the mold.

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