Small-section hollow slab beam core mold for bridge

Abstract

The utility model provides a small-section hollow slab beam core mold for a bridge, and belongs to the technical field of bridge construction. The core mold comprises a shaping main body, a supporting frame, a pull-down piece and an isolation pad, the shaping body comprises a plurality of hollow pipes, and the adjacent hollow pipes are attached to each other to form a continuous outer surface and a continuous inner surface. The inner surface of each hollow pipe is attached to and connected to the corresponding supporting frame in a breakable mode, and the supporting frames are evenly arranged in the length direction of the shaping unit. The pull-down piece is arranged in the supporting frame and is provided with an inhaul cable; and the isolation pad covers the outer surface of the shaping main body. According to the utility model, the plurality of hollow pipes are spliced to form the shaping main body, the supporting frame is adopted to support the shaping main body, and the core mold is split into a plurality of light-weight components, so that the dismounting difficulty of the core mold is reduced; good stability and strength are achieved; by designing the corner core pipes, the connecting core pipes and the standard core pipes, flexible permutation and combination can be carried out, the construction requirements of different abdominal cavity section forms and sizes are met, and the manufacturing and using cost is reduced.

Description

Technical Field

[0001] This utility model belongs to the field of bridge construction technology, and in particular relates to a core mold for small cross-section hollow slab beams of bridges. Background Technology

[0002] Precast hollow slab girders offer numerous advantages, including lightweight, robustness, economy, and stability, and are widely used as the main span structure for small and medium-sized bridges in highways, railways, and urban roads. Current technologies typically employ rigid formwork made of steel plates, PVC boards, or high-density foam as core molds for hollow slab girder construction. However, due to the small size of hollow slab girders in small and medium-sized bridges, with internal hollow cavity cross-sections generally ranging from 40cm to 70cm, workers cannot access the hollow slab girder cavity to remove the core mold after the concrete pouring is complete. This makes core mold removal difficult, time-consuming, labor-intensive, and prone to damaging the surface of the formed concrete. Utility Model Content

[0003] To solve the above-mentioned technical problems, this utility model provides a core mold for small cross-section hollow slab beams of bridges, which solves the problem of the core mold being difficult to remove after construction, realizes the reuse of the core mold, and reduces the manufacturing and use costs.

[0004] The technical solution adopted by this utility model is: a core mold for a small cross-section hollow slab beam of a bridge, comprising a shaping body, a support frame pull-down component, and an isolation pad; the shaping body comprises a plurality of hollow tubes, adjacent hollow tubes being fitted together to form a continuous outer surface and inner surface; the inner surface of each hollow tube is fitted together and brokenably connected to the support frame, the support frame being uniformly arranged along the length direction of the shaping body; the pull-down component is disposed inside the support frame and is provided with a pull cable; the isolation pad covers the outer surface of the shaping body.

[0005] Furthermore, the hollow tube includes a corner core tube, a connecting core tube, and a rectangular core tube, with the connecting core tube disposed between the rectangular core tube and the corner core tube.

[0006] Furthermore, the rectangular core tube, the connecting core tube, and the corner core tube are symmetrically arranged about the length of the shaped main body cross section.

[0007] Furthermore, the support frame includes several end-to-end connected support members, each support member having a mating surface and a vertical surface. The mating surface is mated to the hollow tube and spot-welded, and the pull-down member is connected to the vertical surface.

[0008] Furthermore, the corners of the support frame are provided with chamfered bevels, and an air cushion is provided between the chamfered bevels and the shaping body.

[0009] Furthermore, the hollow tubes are joined together to form a top shaping unit, a bottom shaping unit, and a side shaping unit, with the side shaping unit disposed between the top shaping unit and the bottom shaping unit.

[0010] Furthermore, the support frame includes a bottom support frame, a top support frame, and a side support frame, which are respectively provided corresponding to the top shaping unit, the bottom shaping unit, and the side shaping unit.

[0011] Furthermore, the lateral support is connected to the bottom support and the top support via a slanted wedge joint.

[0012] Furthermore, the two ends of the pull-down member are respectively connected to the middle of the bottom support and the top support.

[0013] The construction method for the core mold of a small-section hollow slab beam for bridges, as described above, includes the following steps:

[0014] Hollow tubes and support frames are designed and manufactured according to the cross-sectional shape of the hollow slab beam;

[0015] Install the pull-down component onto the support frame;

[0016] Assemble the bottom shaping unit;

[0017] An inflatable pad is attached to the designated position of the bottom shaping unit;

[0018] Install the support frame and spot weld the support frame to the hollow tube that makes up the bottom shaping unit.

[0019] The inflatable pad is attached to the designated position on the support frame;

[0020] The lateral shaping unit is installed from bottom to top, and the lateral shaping unit and the support frame are spot welded together;

[0021] Install the top shaping unit and spot weld the top shaping unit and the support frame;

[0022] The gaps are filled with polyurethane foam, and an insulating pad is wrapped around the outer surface of the main body.

[0023] After construction is completed, the support frame and the pull-down component are removed by pulling the cable.

[0024] The top shaping unit, the side shaping unit, and the bottom shaping unit are removed in a symmetrical, top-to-bottom order.

[0025] The advantages and positive effects of this utility model are as follows: This application assembles multiple hollow tubes into a fixed body and uses a support frame to support the fixed body. The core mold is disassembled into multiple lightweight components, so construction personnel do not need to enter the cavity to easily remove the core mold from the inside out, which reduces the difficulty of core mold removal and improves construction efficiency. In addition, this design also reduces the overall weight of the core mold, reduces the difficulty of moving and installing the core mold, and enables the core mold to be reused.

[0026] By spot-welding each hollow tube to the support frame, the core molds are connected to form a closed overall structure with good stability and strength. By designing corner core tubes, connecting core tubes, and rectangular core tubes, the rectangular core tubes are manufactured in a standardized manner according to a set module, while the corner core tubes and connecting core tubes are manufactured according to requirements. This allows for flexible arrangement and combination to meet the construction needs of different abdominal cavity cross-sectional shapes and sizes, thereby reducing manufacturing and usage costs. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of a small-section hollow slab beam structure for bridges, representing a specific embodiment of this utility model.

[0028] Figure 2 This is a schematic diagram of a core mold structure according to a specific embodiment of this utility model;

[0029] Figure 3 This is a schematic diagram of a rectangular core tube structure according to a specific embodiment of this utility model;

[0030] Figure 4 This is a schematic diagram of the corner core tube structure of a specific embodiment of this utility model;

[0031] Figure 5 This is a schematic diagram of the connecting core tube structure of a specific embodiment of this utility model;

[0032] Figure 6 This is a schematic diagram of a support structure according to a specific embodiment of this utility model;

[0033] Figure 7 This is a schematic diagram of the pull-down component structure of a specific embodiment of this utility model.

[0034] In the picture:

[0035] 1. Hollow core beam; 2. Abdomen; 3. Rectangular core tube; 4. Corner core tube; 5. Connecting core tube; 6. Support frame; 61. Support component; 7. Pull-down device; 71. Cable; 8. Inflatable cushion; 9. Isolation pad. Detailed Implementation

[0036] The embodiments of this utility model will now be described with reference to the accompanying drawings.

[0037] This invention proposes a core mold for small-section hollow slab beams of bridges, used to shape the concrete during the pouring of the hollow slab beam concrete to form a cavity with a designed cross-sectional shape; typically, the cross-sectional shape of this cavity is designed as rectangular, circular, elliptical, trapezoidal, or other irregular cross-sectional forms. Figure 1 The image shows a hollow slab beam 1 with an octagonal cross-section for the cavity 2. In the prior art, a fixed rigid template is usually made according to the cross-sectional shape of the cavity 2 of the hollow slab beam 1 for construction. The fixed rigid template is usually made of steel plate, PVC board or high-density foam. However, because the cross-sectional size of the cavity 2 of the small cross-section hollow slab beam of the bridge is small, the construction personnel cannot enter the cavity 2 to dismantle it after the concrete is formed.

[0038] To address the aforementioned technical problems, this application proposes a core mold for small-section hollow slab beams of bridges, such as... Figure 1 As shown, the structure includes a shaping body, a support frame 6, a pull-down component 7, and an isolation pad 9. The shaping body comprises multiple hollow tubes, with adjacent hollow tubes bonded together to form a continuous outer and inner surface, forming a cavity 2 with a designed cross-sectional shape. The inner surface of each hollow tube is bonded to and detachably connected to the support frame 6, which is uniformly arranged along the length of the shaping unit to provide effective support for the shaping body. The pull-down component 7 is located inside the support frame 6 and is equipped with a cable 71. After construction, pulling the cable 71 breaks the connection between the support frame 6 and the shaping body, facilitating the removal of the support frame 6 inside the cavity 2. Subsequently, the hollow tubes are removed one by one. The isolation pad 9 covers the outer surface of the shaping body to form a waterproof isolation layer, preventing grout from seeping into the outside of the shaping body during concrete pouring and thus avoiding adverse effects on the removal of the shaping body.

[0039] The hollow tubes of the aforementioned molded body fit together but are not fixedly connected to each other; the shape of the outer surface formed by the hollow tubes is constructed to match the shape of the cavity 2 of the hollow slab beam 1, so as to form a cavity 2 with a set cross-sectional shape; the aforementioned multiple hollow tubes form a hollow structure, which is provided with a support frame 6 inside. The support frame 6 is set inside the molded body along the length direction at a set interval to form effective support for the molded body; through the above technical solution, the overall core mold forms a closed structure, which not only ensures its stability and strength, enabling it to better resist the buoyancy force, impact force and vibration force of the vibrating equipment transmitted to the core mold during concrete pouring, but also, by disassembling the core mold into multiple lightweight components, construction personnel can easily remove the core mold from the inside out without entering the cavity 2, reducing the difficulty of core mold removal and improving construction efficiency; in addition, this design also reduces the overall weight of the core mold, reducing the difficulty of moving and installing the core mold.

[0040] The hollow tube mentioned above is a steel tube with a hollow structure. Its cross-sectional shape and size are designed according to the cross-section of the cavity 2 of the hollow slab beam 1. Preferably, when used for hollow slab beam 1 with a cross-section of rectangular or trapezoidal, the hollow tube in this application includes a corner core tube 4, a connecting core tube 5, and a rectangular core tube 3. The connecting core tube 5 is disposed between the rectangular core tube 3 and the corner core tube 4. Specifically, the corner core tube 4 is constructed to match the corner shape of the rectangular or trapezoidal cross-section. The rectangular core tube 3 is a steel tube with a fixed size and a square or rectangular cross-section. Several rectangular core tubes 3 and corner core tubes 4 are assembled according to certain rules to form a cavity 2 with a notch. The connecting core tube 5 is made according to the shape of the notch. Preferably, the connecting core tube 5 is located between the rectangular core tube 3 and the corner core tube 4. The three surround each other to form a fixed body with a continuous outer surface and inner surface. This technical solution enables the rectangular core tube 3 to be manufactured in a rectangular shape according to a set module, while the corner core tubes 4 and connecting core tubes 5 are manufactured in a fixed shape according to requirements. By flexibly arranging and combining different corner core tubes 4, connecting core tubes 5 and rectangular core tubes 3, cavities 2 with different cross-sectional shapes and sizes can be formed to meet the construction requirements of different hollow slab beams 1. This simplifies the manufacturing process of the rectangular core tube 3, enables the reuse of the rectangular core tube 3, and reduces manufacturing and usage costs.

[0041] In a specific embodiment, such as Figure 2 , Figure 3 and Figure 4 The structure of a hollow tube for a hollow slab beam 1 with a chamfered rectangular cross-section for the abdominal cavity 2 is shown. The cross-section of the abdominal cavity 2 of the hollow slab beam 1 gradually decreases from one end to the other. The cross-section of the rectangular core tube 3 is designed to be rectangular, and the cross-section of the corner core tube 4 is a right-angled triangle, which is made according to the shape of the chamfered part of the abdominal cavity 2. The cross-section of the connecting core tube 5 is rectangular and the cross-section size gradually decreases from one end to the other. By combining and splicing the corner core tube 4, the connecting core tube 5 and the rectangular core tube 3 in the designed manner, a fixed body that is adapted to the cross-section of the abdominal cavity 2 of the hollow slab beam 1 can be formed.

[0042] Furthermore, the rectangular core tube 3, connecting core tube 5, and corner core tube 4 in this application are symmetrically arranged about the length of the shaped body section. This technical solution allows the load during concrete pouring to be evenly distributed along the length of the shaped body section, thereby avoiding the problem of local stress concentration, which helps to improve the load-bearing capacity and overall stability of the shaped body, and enhances the overall strength of the shaped body.

[0043] Furthermore, the aforementioned support frame 6 includes several support members 61 connected end to end. Each support member 61 includes a mating surface and a vertical surface. The mating surface is mated to the hollow tube and connected by a breakable connection. The function of this connection is to temporarily fix the hollow tube to the support frame 6. The connection can be made by spot welding, adhesive bonding, or wire binding, etc., preferably spot welding. The vertical surface is perpendicularly connected to the mating surface and is located on the opposite inner side of the support frame 6. The pull-down member 7 is connected to the vertical surface. The function of the spot welding connection is to form a temporary fixing method, so that the support frame 6 and the shaping body can be connected as one body, which is convenient for positioning the shaping body and prevents the relative displacement between the shaping body and the support frame 6 during the movement of the overall core mold and the concrete pouring process, which would affect the forming effect and quality of the hollow slab beam 1. At the same time, it is also convenient to remove the connection between the two by applying a small external force after construction, which is convenient for the individual dismantling of each component.

[0044] Furthermore, the corners of the support frame 6 are provided with chamfered bevels, and an air cushion 8 is provided between the chamfered bevels and the shaping body. The air cushion 8 is tightly connected to both the chamfered bevels and the shaping body. Since the air cushion 8 has a certain degree of elasticity and compressibility, it can adapt to the slight deformation that may occur between the support frame 6 and the shaping body during use, thus avoiding gaps between the support frame 6 and the shaping body. At the same time, it is easier for workers to assemble the components. The sharp angle design of the corners of the support frame 6 reduces the possible wear and improves the overall integrity of the support frame 6 and the shaping body.

[0045] In a specific embodiment, such as Figure 2 As shown, hollow tubes are joined together to form a top shaping unit, a bottom shaping unit, and a side shaping unit, with the side shaping unit positioned between the top and bottom shaping units. In this embodiment, both the top and bottom shaping units include three rectangular core tubes 3 located at the midpoint of the cross-section of the shaping main body, and connecting core tubes 5 and corner core tubes 4 located on both sides of the three rectangular core tubes 3. Each of the two side shaping units includes two connecting core tubes 5 and two rectangular core tubes 3. The cross-section formed by the outer surfaces of the top, bottom, and side shaping units is octagonal, and the cross-section formed by the inner surfaces is rectangular. Both the octagon and the rectangle are symmetrical about the centerline along the width direction of the shaping main body cross-section.

[0046] Furthermore, the support frame 6 includes a bottom support, a top support, and a side support, which are respectively provided with the top shaping unit, the bottom shaping unit, and the side shaping unit. Specifically, the bottom support is attached to and spot-welded to the inner surface of the bottom shaping unit, the top support is attached to and spot-welded to the inner surface of the top support, and the side support is attached to and spot-welded to the inner surface of the side shaping unit, so that the support frame 6 provides more effective and balanced support for the shaping body.

[0047] The lateral supports are connected to the bottom and top supports via oblique wedge joints. In one specific embodiment, the lateral supports, bottom supports, and top supports are all welded from angle steel, with a 45-degree oblique wedge joint between adjacent angle steels. The connection surface between the inflatable cushion 8 and the chamfered surface of the support frame 6 is slightly smaller than the chamfered surface. This design allows operators to easily refer to the position of the oblique wedge joint to correctly install the inflatable cushion 8 onto the chamfered surface of the support frame 6, ensuring that the centerline of the inflatable cushion 8 coincides with the oblique centerline of the support frame 6.

[0048] The two ends of the pull-down component 7 are respectively connected to the middle of the bottom support and the top support. Specifically, the pull-down component 7 is made of rod-shaped or strip-shaped steel, and its two ends are welded to the bottom support and the top support respectively. The cable 71 can be made of steel wire rope or steel strand and is fixed in the middle of the pull-down component 7. The cable 71 has sufficient length so that when the support frame 6 and the shaping body are installed, the other end of the cable 71 is pulled to the outside of the shaping body so that external force can be applied to the support frame 6 through the cable 71 after construction is completed, so that the support frame 6 can be separated from the shaping body and dismantled one by one.

[0049] The construction method for the core mold of small-section hollow slab beams for bridges proposed in this application includes the following steps:

[0050] S1. Design the hollow tube and support frame 6 according to the cross-sectional shape of the hollow slab beam 1 and then finalize and manufacture them.

[0051] Specifically, the shape, specifications, and quantity of the rectangular core tube 3, corner core tube 4, connecting core tube 5, support frame 6, and tie rod 7 are determined according to the cross-sectional shape of the hollow slab beam 1. The rectangular core tube 3, corner core tube 4, connecting core tube 5, support frame 6, and tie rod 7 are manufactured in the factory or prefabrication site. The corners and weld scars are polished smooth and flat, and then stored in categories.

[0052] S2. Install the pull-down component 7 onto the support frame 6;

[0053] S3, Assembly of bottom shaping unit;

[0054] Choose a flat plane as the assembly platform, draw the center line of the core mold on the assembly platform, first place the rectangular core tube 3 from the center line to both sides, then place the connecting core tube 5 and the corner core tube 4 in sequence, and the two adjacent hollow tubes fit together to form the top shaping unit.

[0055] S4. Attach the air cushion 8 to the designated position of the bottom shaping unit;

[0056] The inflatable pad 8 is a strip of a certain length. According to the intended installation position of the support frame 6, the inflatable pad 8 is pasted onto the bottom shaping unit.

[0057] S5. Install the support frame 6 and spot weld the support frame 6 to the hollow tube that makes up the bottom shaping unit.

[0058] When installing the support frame 6, the oblique wedge seam at the bottom of the support frame 6 should be aligned with the center line of the air cushion 8 so that the support frame 6 presses the air cushion 8 tightly. Then, the support frame 6 is spot welded to the hollow tube at its bottom.

[0059] S6. Attach the air cushion 8 to the designated position on the support frame 6;

[0060] Attach the air cushion 8 to the chamfered edge of the upper part of the support frame 6, and align the center line of the air cushion 8 with the corresponding oblique wedge during installation.

[0061] S7. Install the lateral shaping unit from bottom to top, and spot weld the lateral shaping unit and the support frame 6 together;

[0062] First, place the connecting core tube 5, which forms the lateral shaping unit, at the designed position above the corner core tube 4 of the bottom shaping unit, and spot weld the connecting core tube 5 to the support frame 6; then install the rectangular core tube 3 and the connecting core tube 5 above the rectangular core tube 3. After each hollow tube is installed in place, spot weld it to the support frame 6, and then install the other hollow tube above it; during installation, ensure that the lateral shaping units on the left and right sides are symmetrical.

[0063] S8. Install the top shaping unit and spot weld the top shaping unit and the support frame 6;

[0064] First, place the rectangular core tubes 3 that make up the top shaping unit on the upper part of the support frame 6 from the center line to both sides, and spot weld them to the support frame 6 respectively; install the connecting core tubes 5 and corner core tubes 4 from the center to the left and right sides in sequence. After each hollow tube is installed in place, it is spot welded to the support frame 6, and then install another hollow tube on one side; until each hollow tube of the top shaping unit is spot welded to the support frame 6.

[0065] S9. Use polyurethane foam to fill the gaps and cover the outer surface of the main body with an isolation pad 9.

[0066] After the core module assembly is completed, a lifting device is used to move the core module onto a platform, suspending it in mid-air. Polyurethane foam is used to fill the gaps between the components of the core module, and then the protruding foam is cut off with a blade. Finally, an isolation pad 9 is wrapped around the entire outer surface of the core module.

[0067] S10. After construction is completed, the support frame 6 and the pull-down component 7 can be removed by pulling the cable 71.

[0068] Once the concrete pouring is complete and the concrete strength reaches the strength required for core mold removal, the core mold removal process begins. First, secure the chain hoist to the end of the cable 71. Then, manually pull the chain hoist to remove each of the support frames 6 inside the main body.

[0069] S11. Remove the top shaping unit, side shaping unit and bottom shaping unit in a symmetrical, top-to-bottom order.

[0070] After all the support frames 6 are removed, manual pry bars, sledgehammers, or hammers are used to pry off the rectangular core tubes 3 one by one, starting from the top shaping unit located at the center line of the core mold, removing them from the concrete and taking them out of the cavity 2 of the hollow slab beam 1. Then, the connecting core tubes 5 and corner core tubes 4 of the top shaping unit, and the connecting core tubes 5 and rectangular core tubes 3 of the side shaping unit are removed in the same way. Finally, the rectangular core tubes 3, connecting core tubes 5 and corner core tubes 4 of the bottom shaping unit are removed in sequence from the center to both sides. At this point, the removal of all core molds is completed. The rectangular core tubes 3, corner core tubes 4, connecting core tubes 5, support frames 6 and pull-down parts 7 can all be reused for the construction of the next hollow slab beam 1 core mold.

[0071] This application assembles multiple hollow tubes into a fixed main body, uses a support frame to support the fixed main body, and disassembles the core mold into multiple lightweight components. Construction personnel can easily remove the core mold from the inside out without entering the cavity, reducing the difficulty of core mold removal and improving construction efficiency. In addition, this design also reduces the overall weight of the core mold, reduces the difficulty of moving and installing the core mold, and enables the core mold to be reused.

[0072] By spot-welding each hollow tube to the support frame, the core molds are connected to form a closed overall structure with good stability and strength. By designing corner core tubes, connecting core tubes, and rectangular core tubes, the rectangular core tubes are manufactured in a standardized manner according to a set module, while the corner core tubes and connecting core tubes are manufactured according to requirements. This allows for flexible arrangement and combination to meet the construction needs of different abdominal cavity cross-sectional shapes and sizes, thereby reducing manufacturing and usage costs.

[0073] The embodiments of this utility model have been described in detail above, but the content described is only a preferred embodiment of this utility model and should not be considered as limiting the scope of implementation of this utility model. All equivalent changes and improvements made in accordance with the claims of this utility model should still fall within the patent coverage of this utility model.

Claims

1. A core mold for a small-section hollow slab beam of a bridge, characterized in that: The device includes a shaping body, a support frame, a pull-down component, and a spacer pad. The shaping body comprises multiple hollow tubes, with adjacent hollow tubes bonded together to form a continuous outer and inner surface. The inner surface of each hollow tube is bonded to and detachably connected to the support frame, which is uniformly arranged along the length of the shaping body. The pull-down component is disposed inside the support frame and is equipped with a pull cable. The spacer pad covers the outer surface of the shaping body.

2. The core mold for small-section hollow slab beams of bridges according to claim 1, characterized in that: The hollow tube includes a corner core tube, a connecting core tube, and a rectangular core tube, with the connecting core tube disposed between the rectangular core tube and the corner core tube.

3. The core mold for small-section hollow slab beams of bridges according to claim 2, characterized in that: The rectangular core tube, the connecting core tube, and the corner core tube are arranged symmetrically about the length direction of the shaping main body section.

4. The core mold for small-section hollow slab beams of bridges according to any one of claims 1-3, characterized in that: The support frame includes several end-to-end connected support members. Each support member includes a mating surface and a vertical surface. The mating surface is mated to the hollow tube and spot-welded. The pull-down member is connected to the vertical surface.

5. The core mold for small-section hollow slab beams of bridges according to claim 4, characterized in that: The corners of the support frame are provided with chamfered bevels, and an air cushion is provided between the chamfered bevels and the shaping body.

6. The core mold for small-section hollow slab beams of bridges according to claim 1, 2, 3 or 5, characterized in that: The hollow tubes are assembled to form a top shaping unit, a bottom shaping unit, and a side shaping unit, with the side shaping unit disposed between the top shaping unit and the bottom shaping unit.

7. The core mold for small-section hollow slab beams of bridges according to claim 6, characterized in that: The support frame includes a bottom support frame, a top support frame, and a side support frame, which are respectively provided corresponding to the top shaping unit, the bottom shaping unit, and the side shaping unit.

8. The core mold for small-section hollow slab beams of bridges according to claim 7, characterized in that: The lateral support is connected to the bottom support and the top support by a slanted wedge joint.

9. The core mold for small-section hollow slab beams of bridges according to claim 8, characterized in that: The two ends of the pull-down member are respectively connected to the middle of the bottom support and the top support.

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