Large-span prestressed hollow slab forming structure

Abstract

The embodiment of the utility model provides a large-span prestressed hollow slab forming structure which comprises a bottom template, an upper bidirectional reinforcing mesh, a lower bidirectional reinforcing mesh, a filling box, a ribbed beam reinforcing steel bar group, a height-adjustable support frame, a prestressed steel strand, a fixed anti-floating mechanism and other components, and all the components are matched with one another to construct a stable structure, for example, the ribbed beam reinforcing steel bar group is connected with the upper reinforcing mesh and the lower reinforcing mesh to transmit loads; the supporting frame provides adjustable support for the prestressed steel strand, the fixed anti-floating mechanism resists concrete pouring buoyancy and the like, and the cushion block and the limiting filler strip are further arranged to guarantee the structural stability. Through reasonable layout and construction, loads can be effectively dispersed, bending resistance, shearing resistance and crack resistance of the hollow slab are improved, self weight is reduced, integrity and stability of an internal structure in construction and use are guaranteed, cracks are reduced, the service life is prolonged, meanwhile, the height of the prestressed steel strand can be flexibly adjusted to adapt to different requirements, and the application range is wide. The overall reliability, durability and bearing capacity of the structure are improved, and it is guaranteed that the hollow slab is better in performance under the large-span condition.

Description

[Technical Field]

[0001] This utility model relates to the field of building construction technology, and in particular to a large-span prestressed hollow slab forming structure. [Background Technology]

[0002] In the field of building engineering, the demand for large-span spatial structures has led to the widespread application of prestressed hollow slabs. However, traditional prestressed hollow slab technology faces many challenges.

[0003] From a structural performance perspective, traditional hollow slabs have limited load-bearing capacity in large-span applications. Their bending and shear resistance is insufficient to cope with complex load systems, making them prone to structural deformation and damage, and failing to guarantee the long-term safety and durability of buildings. In the construction phase, the positioning and fixing measures for the internal components of traditional hollow slabs are significantly inadequate. In particular, the buoyancy problem of the infill boxes is extremely prominent. A single hollow slab infill box typically weighs no more than 10 kg, and during concrete pouring, the infill box is highly susceptible to floating due to buoyancy.

[0004] Traditional anti-buoyancy construction methods mainly rely on wire, fixing one end of the wire to the external reinforcing steel of the hollow slab, and threading the other end through the hollow slab and tightening it to the external structure. However, this method is unreliable and cannot guarantee a stable anti-buoyancy effect. In practice, the hollow slab filling box often experiences upward displacement, which adversely affects the structural dimensions of the hollow slab ribs and upper and lower slab strips. Ultimately, this leads to a significant reduction in the forming quality of the prestressed hollow slab, failing to meet the stringent requirements of modern construction engineering for high precision and high quality in large-span spatial structures.

[0005] Furthermore, traditional prestressed hollow slabs also have shortcomings in the laying and application of prestressed steel strands. The lack of specially designed support and adjustment structures makes it difficult to accurately control the laying height of the prestressed steel strands, failing to fully utilize the effects of prestressing in improving the crack resistance and controlling deformation of the hollow slab, thus affecting the overall stability and service life of the prestressed hollow slab structure. [Utility Model Content]

[0006] The purpose of this utility model is to provide a large-span prestressed hollow slab forming structure, aiming to solve at least one of the above-mentioned problems existing in the prior art of large-span prestressed hollow slabs.

[0007] This utility model is achieved through the following technical solution:

[0008] A large-span prestressed hollow slab forming structure includes a bottom formwork, on which a lower bidirectional steel mesh is laid. Multiple filling boxes are positioned above the lower bidirectional steel mesh, and an upper bidirectional steel mesh is laid above the filling boxes. A rib beam steel reinforcement group is positioned between any two adjacent filling boxes. The upper end of the rib beam steel reinforcement group is fixedly connected to the upper bidirectional steel mesh, and its lower end is fixedly connected to the lower bidirectional steel mesh. An adjustable-height support frame is erected on the bottom formwork between any two adjacent filling boxes. Prestressed steel strands are laid on the support frame. A fixed anti-buoyancy mechanism is provided between the bottom of the rib beam steel reinforcement group and the bottom formwork.

[0009] As described above, in a large-span prestressed hollow slab forming structure, the rib beam reinforcement group includes upper longitudinal bars of the rib beam fixedly connected to the upper bidirectional reinforcement mesh, lower longitudinal bars of the rib beam fixedly connected to the lower bidirectional reinforcement mesh, and intermediate anti-buoyancy bars sleeved around the upper longitudinal bars and the lower longitudinal bars of the rib beam.

[0010] As described above, in a large-span prestressed hollow slab forming structure, the fixed anti-buoyancy mechanism includes an anti-buoyancy fixing member disposed on the upper surface of the bottom template, an anti-buoyancy base disposed on the lower surface of the bottom template, and an anti-buoyancy screw that passes through the anti-buoyancy fixing member, the bottom template, and the anti-buoyancy base sequentially from top to bottom. A fixing nut that cooperates with the anti-buoyancy screw is provided above the anti-buoyancy fixing member, and a base nut that cooperates with the anti-buoyancy screw is provided below the anti-buoyancy base. The anti-buoyancy fixing member is used to fix the lower longitudinal reinforcement of the rib beam.

[0011] As described above, in a large-span prestressed hollow slab forming structure, the anti-buoyancy fastener is a channel steel with an opening in the middle, so that the lower longitudinal reinforcement of the rib beam can be inserted and the protective layer thickness between it and the lower surface of the bottom template can be reserved.

[0012] As described above, in a large-span prestressed hollow slab forming structure, the support frame includes a support base mounted on the bottom template. Two symmetrically arranged height adjustment devices are connected to the support base. Each height adjustment device is connected to a support rod, and the upper ends of the two support rods are movably connected to support members that can undergo relative rolling displacement with the prestressed steel strands.

[0013] As described above, in a large-span prestressed hollow slab forming structure, the support base includes a support made of multiple angle irons spliced ​​and fixed together. Multiple support columns are evenly arranged around the support. The support rod is a screw rod. The support has an opening for the screw rod to pass through. The height adjustment device includes a first nut located below the support and connected to the screw rod, and a second nut located above the support and connected to the screw rod. The upper ends of the two screw rods are movably connected to the support member.

[0014] As described above, in a large-span prestressed hollow slab forming structure, the upper ends of the two support rods are respectively provided with U-shaped irons. The support member includes a rolling rod that is erected between the two U-shaped irons and abuts against the prestressed steel strand. The two ends of the rolling rod are provided with limiting parts. When the prestressed steel strand is displaced by external force, the rolling rod rolls with the prestressed steel strand.

[0015] In the large-span prestressed hollow slab molding structure described above, a pad is provided between the lower bidirectional steel mesh and the filling box.

[0016] In the large-span prestressed hollow slab molding structure described above, the side end of the filling box and the rib beam reinforcement are provided with the pad block.

[0017] As described above, in a large-span prestressed hollow slab forming structure, the pad includes a surface support portion that abuts against the filling box, and the surface support portion is connected to a snap-fit ​​portion that can snap into the lower bidirectional steel mesh and the rib beam steel reinforcement group.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] 1. This utility model uses an adjustable-height support frame erected on the bottom template to precisely control the laying height of the prestressed steel strands, fully leveraging the effects of prestressing in improving the crack resistance and controlling deformation of hollow slabs, enhancing the overall stability of the prestressed hollow slab structure, and extending its service life.

[0020] 2. By forming a robust anti-buoyancy connection structure consisting of a fixed anti-buoyancy mechanism, a lower bidirectional steel mesh, an upper bidirectional steel mesh, an infill box, and rib beam steel reinforcement groups, the anti-buoyancy problem of the infill box during concrete pouring is effectively solved, preventing the infill box from floating and deviating, ensuring the accuracy of the structural dimensions of the hollow slab rib beams and upper and lower slab strips, improving the forming quality of the prestressed hollow slab, and further enhancing the load-bearing capacity in large-span situations, improving bending and shear performance, better coping with complex load systems, reducing structural deformation and damage, and ensuring the long-term safety and durability of the building.

[0021] 3. The upper end of the support rod is supported by a rolling rod with a limit part installed on a U-shaped iron frame to form a support component. When the prestressed steel strand is displaced by external force, the rolling rod can roll with it. This support frame structure can not only accurately control the laying height of the prestressed steel strand, but also give full play to the effect of prestress in improving the crack resistance of hollow slabs and controlling deformation, thereby enhancing the overall stability of the prestressed hollow slab structure and extending its service life. [Attached Image Description]

[0022] To more clearly illustrate the technical solutions in the embodiments of the utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0023] Figure 1 This is a schematic diagram of the cross-sectional structure of this embodiment;

[0024] Figure 2 This is a side view of the fixed anti-buoyancy mechanism in this embodiment;

[0025] Figure 3 This is a top view of the fixed anti-buoyancy mechanism in this embodiment;

[0026] Figure 4 This is a front view of the support frame in this embodiment;

[0027] Figure 5 This is a side view of the support frame in this embodiment;

[0028] Figure 6 This is a top view of the support frame in this embodiment;

[0029] Figure 7 This is a front view of the pad block in this embodiment;

[0030] Figure 8 This is the bottom view of the pad block in this embodiment.

Detailed Implementation Methods

[0031] To make the technical problems solved by this application, the technical solutions, and the beneficial effects clearer, this application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0032] Please see Figures 1 to 8This embodiment provides a large-span prestressed hollow slab forming structure, including a bottom template 1, on which a lower bidirectional steel mesh 2 is laid. Above the lower bidirectional steel mesh 2, there are multiple filling boxes 3. Above the filling boxes 3, an upper bidirectional steel mesh 4 is laid. Between any two adjacent filling boxes 3, there is a rib beam steel bar group 5. The upper end of the rib beam steel bar group 5 is fixedly connected to the upper bidirectional steel mesh 4, and its lower end is fixedly connected to the lower bidirectional steel mesh 2. Between any two adjacent filling boxes 3, there is a rib beam steel bar group 5. An adjustable height support frame 6 is erected on the bottom template 1 between any two adjacent filling boxes 3. Prestressed steel strands 7 are laid on the support frame 6. A fixed anti-buoyancy mechanism 8 is provided between the bottom of the rib beam steel bar group 5 and the bottom template 1.

[0033] In this embodiment, the bottom formwork 1 serves as the foundational load-bearing component, providing a stable bottom support plane for the entire prestressed hollow slab structure. A lower bidirectional steel mesh 2 is laid on the bottom formwork 1; its crisscrossing steel reinforcement layout evenly distributes the load, enhancing the local load-bearing capacity of the bottom formwork 1 and effectively preventing localized damage due to concentrated loads, thus improving the uniformity of stress distribution at the bottom of the entire hollow slab. Multiple infill boxes 3 are placed above the lower bidirectional steel mesh 2. The infill boxes 3 are made of lightweight materials, effectively reducing the overall weight of the hollow slab. An upper bidirectional steel mesh 4 is laid above the infill boxes 3 and connected to the lower bidirectional steel mesh 2 via rib beam reinforcement groups 5. The presence of the rib beam reinforcement groups 5 allows the upper and lower bidirectional steel meshes to form an integrated concrete skeleton structure. When the hollow slab is subjected to external loads, such as vertical pressure and horizontal shear force, the rib reinforcement group 5 transfers the load on the upper two-way reinforcement mesh 4 to the lower two-way reinforcement mesh 2. Through the connection between the two and the bottom formwork 1, the load is distributed throughout the entire bottom formwork 1, greatly improving the flexural and shear resistance of the hollow slab and ensuring the stability and safety of the structure under large span conditions. Adjustable height support frames 6 are erected on the bottom formwork 1 and located between adjacent filling boxes 3. Specifically, they are set in the casting area of ​​the hollow slab ribs. Multiple support frames 6 are evenly arranged along the setting path of the rib reinforcement group 5, providing a foundation for the prestressed steel strands 7. Furthermore, the height of the support frame 6 can be flexibly adjusted according to design requirements, providing a suitable laying height position for the prestressed steel strands 7. Prestressed steel strands 7 are pre-stressed within the hollow slab. When the hollow slab is subjected to tensile stress by external loads, the prestressed steel strands 7 can offset part of the tensile stress, thereby significantly improving the crack resistance of the hollow slab, reducing crack formation, and extending its service life. It also increases the rigidity of the hollow slab, making it deform less under load and ensuring the safety and comfort of the structure during use. A fixed anti-buoyancy mechanism 8 is installed between the bottom of the rib reinforcement group 5 and the bottom formwork 1. During the concrete pouring process of the hollow slab, the filling box 3 and the rib reinforcement group 5 are subjected to the buoyancy of the concrete. The fixed anti-buoyancy mechanism 8 can effectively resist buoyancy, ensuring that the filling box 3 and the rib beam reinforcement group 5 remain in a fixed position during concrete pouring. This avoids the internal structure of the hollow slab becoming chaotic due to floating, ensuring the integrity and uniformity of the internal structure of the hollow slab, and thus guaranteeing the overall strength and performance of the hollow slab. It effectively prevents the filling box from floating or shifting during concrete pouring, ensuring sufficient vibration of the concrete at the bottom of the filling box, thereby guaranteeing the quality of concrete pouring and avoiding problems such as cracking or insufficient flatness of the concrete surface.

[0034] Specifically, the rib beam reinforcement group 5 includes an upper longitudinal bar 51 fixedly connected to the upper bidirectional reinforcement mesh 4, a lower longitudinal bar 52 fixedly connected to the lower bidirectional reinforcement mesh 2, and an intermediate anti-buoyancy bar 53 sleeved around the upper longitudinal bar 51 and the lower longitudinal bar 52 of the rib beam. The intermediate anti-buoyancy bar 53 is a closed stirrup of the rib beam.

[0035] In the rib beam reinforcement group 5, the upper longitudinal reinforcement 51 of the rib beam is firmly fixed to the upper bidirectional steel mesh 4 by welding or binding with wire, ensuring a tight connection and effective stress transfer. Similarly, the lower longitudinal reinforcement 52 of the rib beam is reliably fixed to the lower bidirectional steel mesh 2, enabling the entire rib beam reinforcement group 5 to establish a stable force transmission path between the upper and lower steel meshes. The intermediate anti-buoyancy reinforcement 53 adopts the form of closed stirrups in the rib beam, surrounding the upper longitudinal reinforcement 51 and the lower longitudinal reinforcement 52 of the rib beam. During the concrete pouring process, when the filling box 3 and the rib beam reinforcement group 5 are subjected to upward buoyancy, the intermediate section anti-buoyancy reinforcement 53, with its closed stirrup structural characteristics, can apply restraining forces to the upper longitudinal reinforcement 51 and the lower longitudinal reinforcement 52 of the rib beam from multiple directions, effectively preventing them from undergoing relative displacement or deformation due to buoyancy. This further enhances the stability of the rib beam reinforcement group 5 in the concrete pouring environment, ensures the precise forming of the internal structure of the hollow slab during construction, avoids local structural defects in the hollow slab due to the deformation of the reinforcement group, and thus ensures the reliability and consistency of the entire large-span prestressed hollow slab structure performance.

[0036] Furthermore, as a preferred embodiment of this solution and not a limitation, the fixed anti-buoyancy mechanism 8 includes an anti-buoyancy fixing member 81 disposed on the upper surface of the bottom template 1, an anti-buoyancy base 82 disposed on the lower surface of the bottom template 1, and an anti-buoyancy screw 83 passing through the anti-buoyancy fixing member 81, the bottom template 1, and the anti-buoyancy base 82 sequentially from top to bottom. A fixing nut 84 that cooperates with the anti-buoyancy screw 83 is provided above the anti-buoyancy fixing member 81, and a base nut 85 that cooperates with the anti-buoyancy screw 83 is provided below the anti-buoyancy base 82. The anti-buoyancy fixing member 81 is used to fix the lower longitudinal rib 52 of the rib beam.

[0037] In the construction process of the large-span prestressed hollow slab proposed in this embodiment, when assembling components such as the rib beam reinforcement group 5 and the filling box 3, the anti-buoyancy fixing component 81 is placed at the corresponding position on the upper surface of the bottom formwork 1. This anti-buoyancy fixing component 81 has a specially designed slot or clamp structure that can accurately clamp the lower longitudinal reinforcement 52 of the rib beam, thereby initially positioning and fixing the rib beam reinforcement group 5 in the vertical direction, effectively preventing easy vertical displacement during subsequent construction. The anti-buoyancy base 82 is installed at the corresponding position on the lower surface of the bottom formwork 1. The anti-buoyancy screw 83 passes through the anti-buoyancy fixing component 81, the bottom formwork 1, and the anti-buoyancy base 82 sequentially from top to bottom. Above the anti-buoyancy fixing component 81, the fixing nut 84 is threaded into the anti-buoyancy screw 83 and tightened, so that the anti-buoyancy fixing component 81 tightly clamps the lower longitudinal reinforcement 52 of the rib beam, further enhancing the constraint on the rib beam reinforcement group 5. Below the anti-buoyancy base 82, the base nut 85 and the anti-buoyancy screw 83 are tightened together, making the entire fixed anti-buoyancy mechanism 8 a stable integral structure. During concrete pouring, the upward buoyancy force on the filling box 3 and the rib reinforcement group 5 is transmitted to the anti-buoyancy fixing member 81. The anti-buoyancy fixing member 81 transmits the force to the anti-buoyancy base 82 through the anti-buoyancy screw 83, and finally the anti-buoyancy base 82 evenly distributes the force to the bottom formwork 1 and the entire support system. This design of the fixed anti-buoyancy mechanism 8 can accurately and effectively resist the buoyancy effect during the concrete pouring process, ensuring the accurate position of the rib reinforcement group 5 and the filling box 3 inside the hollow slab, avoiding structural deformation or positional displacement caused by buoyancy, thereby ensuring the integrity and stability of the internal structure of the large-span prestressed hollow slab, and improving the forming quality and overall performance of the hollow slab.

[0038] Furthermore, as a preferred embodiment of this solution and not a limitation, the anti-buoyancy fastener 81 is a channel steel with an opening in the middle, so that the lower longitudinal reinforcement 52 of the rib beam can be inserted and a protective layer thickness between it and the lower surface of the bottom template 1 can be reserved.

[0039] In this embodiment, due to the special structure of the channel steel, its opening size is matched with the diameter of the lower longitudinal reinforcement 52 of the rib beam, enabling precise positioning and fixing, and effectively preventing the lower longitudinal reinforcement 52 of the rib beam from shifting in the horizontal direction. At the same time, the height design of the channel steel cleverly reserves the thickness of the protective layer between it and the lower surface of the bottom formwork 1, which can effectively prevent the reinforcement from rusting due to contact with the bottom formwork 1, thereby extending the service life of the hollow slab.

[0040] Furthermore, as a preferred embodiment of this solution and not a limitation, the support frame 6 includes a support base 61 mounted on the bottom template 1. Two symmetrically arranged height adjustment devices 62 are connected to the support base 61. Support rods 63 are respectively connected to the height adjustment devices 62. Support members 64 that can undergo relative rolling displacement with the prestressed steel strands 7 are movably connected to the upper ends of the two support rods 63.

[0041] In this embodiment, the height adjustment device 62 can take the form of a threaded adjusting rod or a hydraulic jack. By rotating the threaded adjusting rod or controlling the extension and retraction of the hydraulic jack, the height of the support rod 63 can be precisely adjusted. This symmetrically arranged height adjustment device 62 ensures that the two support rods 63 remain synchronized and evenly stressed during the height adjustment process, avoiding uneven laying of the prestressed steel strand 7 or uneven stress on the support frame 6 due to inconsistent heights.

[0042] The upper end of the support rod 63 is movably connected to the support member 64. The support member 64 can adopt a special rolling structure or a low-friction coefficient sliding bearing structure, enabling it to undergo relative rolling displacement with the prestressed steel strand 7. When the prestressed steel strand 7 undergoes expansion and contraction deformation during tensioning or due to factors such as temperature changes, the support member 64 can adapt to this deformation, avoiding additional frictional resistance or constraint stress on the prestressed steel strand 7, thereby ensuring the prestressing effect of the prestressed steel strand 7 and its normal working condition during use.

[0043] Furthermore, as a preferred embodiment of this solution and not a limitation, the support base 61 includes a support 611 formed by splicing and fixing multiple angle irons. Multiple support columns 612 are evenly arranged around the support 611. The support rod 63 is a screw rod. The support 611 has an opening for the screw rod to pass through. The height adjustment device 62 includes a first nut 621 located below the support 611 and connected to the screw rod, and a second nut 622 located above the support 611 and connected to the screw rod. The upper ends of the two screw rods are movably connected to the support member 64.

[0044] In this embodiment, four angle irons are welded into a rectangular support 611 to ensure that the support 611 has sufficient strength and stability to support the subsequent support column 612 and other components.

[0045] Four support columns 612 are evenly installed around the support 611. The support columns 612 can be made of common steel bars, which are simple to obtain and have reliable strength. The support columns 612 are connected to the support 611 by welding or high-strength bolts, so that the support columns 612 can stably support the entire support frame structure.

[0046] The support rod 63 is a screw rod, which passes through a pre-set opening on the support 611. The height adjustment device 62 is connected to the screw rod via a first nut 621 located below the support 611 and a second nut 622 located above the support 611. In operation, the construction personnel can precisely adjust the extension length of the screw rod and tighten it by rotating the first nut 621 and the second nut 622, thereby changing the height of the support rod 63 to adapt to different construction requirements and the laying height requirements of the prestressed steel strand 7.

[0047] Furthermore, as a preferred embodiment of this solution and not a limitation, the upper ends of the two support rods 63 are respectively provided with U-shaped irons 631, and the support member 64 includes a rolling rod 642 that is mounted between the two U-shaped irons 631 and abuts against the prestressed steel strand 7. The two ends of the rolling rod 642 are provided with limiting parts 643. When the prestressed steel strand 7 is displaced by external force, the rolling rod 642 rolls with the prestressed steel strand 7.

[0048] In this embodiment, U-shaped irons 631 are welded to the upper ends of the two support rods 63 respectively. The U-shaped irons 631 are preferably made of sturdy and smooth steel, and their openings are adapted to the diameter of the rolling rod 642 to stably support it. The rolling rod 642 is placed between the two U-shaped irons 631. Limiting portions 643 are provided at both ends of the rolling rod 642. The limiting portions 643 can be protruding annular structures or baffles welded to both ends of the rolling rod 642, their function being to prevent the rolling rod 642 from detaching from the U-shaped irons 631 during rolling. Prestressed steel strands 7 are laid above and abut against the rolling rods 642. When the prestressed steel strands 7 are displaced due to tensioning operations, temperature changes, or other external forces, the rolling rods 642 will roll along with the movement of the prestressed steel strands 7. For example, during the tensioning process of the prestressed steel strand 7, the strand gradually elongates, and the rolling rod 642 rolls synchronously under the frictional force of the strand, making the relative motion between the strand and the rolling rod 642 rolling friction rather than sliding friction. This rolling friction method greatly reduces the wear on the bonding layer of the prestressed steel strand 7, ensuring the structural integrity and prestress transfer effect of the prestressed steel strand 7. Simultaneously, due to the presence of the support base 61 and the height adjustment device 62, the height of the support rod 63 can be adjusted at any time according to design requirements and actual construction conditions, thereby adjusting the height of the rolling rod 642 to adapt to the support requirements of the prestressed steel strand at different positions in the spatial curve of the large-span prestressed hollow slab. Whether the prestressed steel strand 7 is in a plane or on a spatial curve, the support frame 6 provides stable and adjustable support, effectively ensuring the correct position and good working condition of the prestressed steel strand 7 in the large-span prestressed hollow slab, improving the reliability, durability, and load-bearing capacity of the overall hollow slab structure.

[0049] Furthermore, as a preferred embodiment of this solution and not a limitation, a pad 9 is provided between the lower bidirectional steel mesh 2 and the filling box 3. The pad 9 is provided at the side end of the filling box 3 and the rib beam steel reinforcement group 5. The pad 9 includes a surface support part 91 that abuts against the filling box 3. The surface support part 91 is connected to a snap-fit ​​part 92 that can snap onto the lower bidirectional steel mesh 2 and the rib beam steel reinforcement group 5. The snap-fit ​​part 92 is a cross groove.

[0050] In this embodiment, the pad 9 is a frustum-shaped pad made of high-strength plastic or concrete, and the planar shape of its surface support 91 fits the contact surface of the filling box 3 to ensure a good contact effect.

[0051] During the preparation for hollow slab pouring, spacer blocks 9 are placed on the lower bidirectional reinforcing mesh 2. Their locking parts 92, with their cross-grooved structure, facilitate easy connection with the reinforcing bars of the lower bidirectional reinforcing mesh 2. In practice, the reinforcing bars are embedded into the cross-grooves, fixing the spacer block 9 in place on the lower bidirectional reinforcing mesh 2 and effectively preventing displacement during subsequent construction. When placing the filling box 3, the bottom of the filling box 3 is in close contact with the surface support part 91 of the spacer block 9. The presence of the spacer block 9 ensures a suitable distance between the filling box 3 and the lower bidirectional reinforcing mesh 2. This distance provides sufficient space for concrete pouring, ensuring that the concrete fully encloses the reinforcing bars and the filling box 3, thus improving the overall integrity and strength of the structure.

[0052] Simultaneously, a spacer 9 is also installed between the side end of the filling box 3 and the reinforcing steel rib group 5. The snap-fit ​​part 92 of the spacer 9 is snapped into the reinforcing steel rib group 5, fixing the spacer 9 onto the reinforcing steel rib group 5, and its surface support part 91 abuts against the side end of the filling box 3. This ensures the horizontal stability of the filling box 3, preventing it from shifting due to concrete compression during concrete pouring, and ensuring the accuracy and stability of the internal structure of the hollow slab.

[0053] Furthermore, as a preferred embodiment of this solution, and not a limitation thereof, a limiting strip 10 is provided between the filling box 3 and the upper bidirectional reinforcing mesh 4 to restrict the upward floating of the filling box 3. The limiting strip 10, through its interaction with the upper bidirectional reinforcing mesh 4, applies downward pressure or a restrictive force to the filling box 3. During concrete pouring, when the filling box 3 is subjected to the upward buoyancy force of the concrete, the limiting strip 10 can effectively prevent the filling box 3 from floating upward, further improving the anti-buoyancy effect.

[0054] Working principle of this embodiment:

[0055] This embodiment proposes a structural scheme for large-span prestressed hollow slabs, comprising a bottom formwork, upper and lower bidirectional steel mesh, infill box, ribbed steel reinforcement assemblies, adjustable-height support frames, prestressed steel strands, and a fixed anti-buoyancy mechanism. These components work together to construct a stable structure. For example, the ribbed steel reinforcement assemblies connect the upper and lower steel meshes to transfer loads; the support frames provide adjustable support for the prestressed steel strands; and the fixed anti-buoyancy mechanism resists the buoyancy of poured concrete. Additionally, spacers and limiting strips ensure structural stability. Through reasonable layout and construction, the load is effectively distributed, improving the hollow slab's bending, shear, and crack resistance, reducing its self-weight, ensuring the integrity and stability of the internal structure during construction and use, reducing crack formation, and extending service life. Simultaneously, the height of the prestressed steel strands can be flexibly adjusted to adapt to different needs, improving the overall reliability, durability, and load-bearing capacity of the structure, ensuring superior performance of the hollow slab in large-span applications.

[0056] The above are implementation methods provided in conjunction with specific content, and it is not intended that the specific implementation of this application is limited to these descriptions. Any methods or structures that are similar to those of this application, or any technical deductions or substitutions made based on the concept of this application, should be considered within the scope of protection of this application.

Claims

1. A large-span prestressed hollow slab forming structure, comprising a bottom formwork (1), on which a lower bidirectional steel mesh (2) is laid, and above the lower bidirectional steel mesh (2) are multiple filling boxes (3), and above the filling boxes (3) is an upper bidirectional steel mesh (4), characterized in that: A rib beam steel bar group (5) is provided between any two adjacent filling boxes (3). The upper end of the rib beam steel bar group (5) is fixedly connected to the upper bidirectional steel mesh (4), and its lower end is fixedly connected to the lower bidirectional steel mesh (2). A rib beam steel bar group (5) is provided between any two adjacent filling boxes (3). An adjustable height support frame (6) is erected on the bottom template (1) between any two adjacent filling boxes (3). Prestressed steel strands (7) are laid on the support frame (6). A fixed anti-buoyancy mechanism (8) is provided between the bottom of the rib beam steel bar group (5) and the bottom template (1).

2. The large-span prestressed hollow slab forming structure according to claim 1, characterized in that, The rib beam reinforcement group (5) includes an upper longitudinal bar (51) fixedly connected to the upper bidirectional steel mesh (4), a lower longitudinal bar (52) fixedly connected to the lower bidirectional steel mesh (2), and an intermediate anti-buoyancy bar (53) sleeved around the upper longitudinal bar (51) and the lower longitudinal bar (52) of the rib beam.

3. The large-span prestressed hollow slab forming structure according to claim 2, characterized in that, The fixed anti-buoyancy mechanism (8) includes an anti-buoyancy fixing member (81) on the upper surface of the bottom template (1), an anti-buoyancy base (82) on the lower surface of the bottom template (1), and an anti-buoyancy screw (83) passing through the anti-buoyancy fixing member (81), the bottom template (1), and the anti-buoyancy base (82) from top to bottom. A fixing nut (84) that cooperates with the anti-buoyancy screw (83) is provided above the anti-buoyancy fixing member (81), and a base nut (85) that cooperates with the anti-buoyancy screw (83) is provided below the anti-buoyancy base (82). The anti-buoyancy fixing member (81) is used to fix the lower longitudinal reinforcement (52) of the rib beam.

4. The large-span prestressed hollow slab forming structure according to claim 3, characterized in that, The anti-buoyancy fastener (81) is a channel steel with an opening in the middle, so that the lower longitudinal reinforcement (52) of the rib beam can be inserted and the protective layer thickness between it and the lower surface of the bottom template (1) can be reserved.

5. The large-span prestressed hollow slab forming structure according to claim 1, characterized in that, The support frame (6) includes a support base (61) mounted on the bottom template (1). Two symmetrically arranged height adjustment devices (62) are connected to the support base (61). Support rods (63) are connected to the height adjustment devices (62). Support members (64) that can roll relative to the prestressed steel strands (7) are movably connected to the upper ends of the two support rods (63).

6. The large-span prestressed hollow slab forming structure according to claim 5, characterized in that, The support base (61) includes a support (611) assembled and fixed from multiple angle iron pieces. Multiple support columns (612) are evenly arranged around the support (611). The support rod (63) is a screw rod. The support (611) has an opening for the screw rod to pass through. The height adjustment device (62) includes a first nut (621) located below the support (611) and connected to the screw rod, and a second nut (622) located above the support (611) and connected to the screw rod. The upper ends of the two screw rods are movably connected to the support member (64).

7. A large-span prestressed hollow slab forming structure according to claim 6, characterized in that, The upper ends of the two support rods (63) are respectively provided with U-shaped iron (631). The support member (64) includes a rolling rod (642) that is erected between the two U-shaped irons (631) and abuts against the prestressed steel strand (7). The two ends of the rolling rod (642) are provided with limiting parts (643). When the prestressed steel strand (7) is displaced by external force, the rolling rod (642) rolls with the prestressed steel strand (7).

8. A large-span prestressed hollow slab forming structure according to claim 1, characterized in that, A pad (9) is provided between the lower bidirectional steel mesh (2) and the filling box (3).

9. A large-span prestressed hollow slab forming structure according to claim 8, characterized in that, The side end of the filling box (3) and the rib beam steel reinforcement group (5) are provided with the pad (9).

10. A large-span prestressed hollow slab forming structure according to claim 9, characterized in that, The pad (9) includes a surface support (91) that abuts against the filling box (3), and the surface support (91) is connected to a snap-fit ​​part (92) that can snap into the lower bidirectional steel mesh (2) and the rib beam steel reinforcement group (5).

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