Bidirectional prestress reduced-overlapping plywood

Abstract

The utility model discloses a two-way prestress weight reduction laminated plate which comprises a prefabricated concrete bottom plate, weight reduction blocks, longitudinal load-bearing steel bars, transverse distribution steel bars, reinforcing ribs and transverse pipelines. Longitudinal prestress load-bearing steel bars and transverse distribution steel bars are arranged in the prefabricated concrete bottom plate. Reinforcing ribs are arranged on the concrete bottom plate; the weight reducing blocks are laid on the prefabricated concrete bottom plate, and the weight reducing blocks are spaced by a certain distance. According to the device, a plurality of prefabricated concrete bottom plates are spliced together, the transverse pipelines are connected into a straight line, and the post-tensioned prestressed steel bars penetrate through the pipelines and are tensioned, so that the bidirectional prestressed floor is formed, the bidirectional rigidity of a floor system can be consistent, the bidirectional force transmission performance and the bidirectional anti-cracking effect are better, the integrity of the floor system is better, and more steel materials are saved.

Description

Technical Field

[0001] This utility model specifically relates to the field of building engineering technology, and specifically to a two-way prestressed reduced-stress composite slab, which can be widely used in the floor slabs of various buildings. Background Technology

[0002] Existing prestressed composite slabs mainly include concrete-ribbed composite slabs and steel pipe truss prestressed composite slabs. Current technologies all employ reinforcing ribs on a concrete base slab, with gaps or holes for inserting reinforcing bars at the junction of the ribs and the concrete base slab. During construction, precast components are assembled first, and then reinforcing bars are inserted perpendicularly to the reinforcing ribs onto the surface of the precast concrete base slab, forming a two-way load-bearing member. Due to the large thickness of the concrete base slab, the protective layer of the inserted reinforcing bars is also thick, severely affecting the load-bearing performance of the inserted reinforcing bars and increasing the risk of cracking later in the component. This problem is particularly pronounced when the floor slab span is large, or when the floor slab contains weight-reducing blocks and the precast concrete base slab is thick. Moreover, current technologies use ordinary reinforcing bars, which easily lead to cracking at the component joints and increase the amount of reinforcing steel used. Especially with existing concrete ribs, when there are weight-reducing blocks, the contact area between the precast base slab and the cast-in-place concrete is small. The concrete reinforcing ribs and the base slab are also poured twice, resulting in weak bond strength between the base slab and the reinforcing ribs, as well as weak bond strength between the cast-in-place concrete and the base slab. As span and load increase, existing technologies cannot meet the structural bearing capacity requirements. Furthermore, leaving holes in the concrete ribs can easily lead to misalignment of the holes during factory processing, making processing more difficult and subsequent quality control challenging. Summary of the Invention

[0003] Therefore, this utility model proposes a bidirectional prestressed reduced-overlap composite plate to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, this utility model discloses a bidirectional prestressed weight-reducing composite slab, comprising: a precast concrete base slab, weight-reducing blocks, reinforcing ribs, longitudinal reinforcing bars, transverse distributed reinforcing bars, and transverse ducts. The precast concrete base slab contains pre-tensioned prestressed longitudinal reinforcing bars and transverse distributed reinforcing bars; the precast concrete base slab is provided with reinforcing ribs and transverse ducts; the transverse ducts traverse the reinforcing ribs.

[0005] In this invention, a reinforced concrete base slab, a weight-reducing block, and transverse ducts for post-tensioned prestressed steel bars are integrated onto a single component. After the floor slab is assembled, a through-tube is connected to the transverse ducts between the components, through which post-tensioned prestressed steel bars are inserted and tensioned, ultimately forming a two-way prestressed weight-reducing composite floor slab. This allows for large-span, heavy-load, two-way isotropic floor slabs with improved overall integrity, crack resistance, and two-way force transmission. Using two-way prestressing significantly reduces the required reinforcement in the floor slab, making construction more convenient.

[0006] Furthermore, as a preferred embodiment, the thickness of the precast concrete base slab is 45mm to 70mm.

[0007] Furthermore, as a preferred embodiment, the reinforcing rib is a concrete rib, which is cast in one piece with the precast concrete base plate.

[0008] Furthermore, as a preferred embodiment, the concrete rib is provided with stirrups.

[0009] Furthermore, as a preferred embodiment, the concrete rib is provided with continuously bent corrugated bars.

[0010] Furthermore, as a preferred embodiment, the reinforcing rib is a steel pipe truss, a steel bar truss, a steel pipe web truss, or a concrete truss rib.

[0011] Furthermore, as a preferred embodiment, the reinforcing rib is a combination of corrugated steel plate and concrete, with the corrugated steel plate serving as the web and concrete, reinforcing bars, or steel pipes serving as the upper flange.

[0012] Furthermore, as a preferred embodiment, the longitudinal reinforcing bars are prestressed steel bars.

[0013] Furthermore, as a preferred embodiment, the transverse pipe is a metal corrugated pipe.

[0014] Furthermore, as a preferred embodiment, the bottom surface of the transverse pipe is 5mm to 20mm lower than the top surface of the precast concrete base plate, and part of it is embedded in the precast concrete base plate.

[0015] Furthermore, as a preferred embodiment, the transverse pipe rests on the surface of the precast concrete base slab and is fixed to the precast concrete base slab.

[0016] Furthermore, as a preferred embodiment, the transverse pipes are perpendicular to the longitudinal reinforcing bars and are arranged in multiple sections with a spacing of not less than 500mm.

[0017] Furthermore, as a preferred embodiment, the weight-reducing block is a steel wire mesh box, a lightweight membrane shell, or a foam board.

[0018] Furthermore, as a preferred embodiment, the weight-reducing block is cast integrally with the precast concrete base slab.

[0019] Furthermore, as a preferred embodiment, the weight-reducing block is placed on a precast concrete base slab and fixed to the precast concrete base slab.

[0020] Furthermore, preferably, the weight-reducing block is disposed within the area enclosed by the reinforcing rib and the transverse pipe.

[0021] This utility model, employing the above-mentioned technology, has the following advantages compared to existing technologies: This utility model combines a ribbed concrete base slab, weight-reducing blocks, and transverse sleeves to form a new type of composite slab—used for bidirectional prestressed weight-reducing prefabricated composite slabs. This technology allows for prestressing in both directions of the composite slab, with the concrete cover thickness for the reinforcement in both directions being less than 30mm, consistent with the design value. This results in reduced steel consumption and more rational component design. Component processing is simple, and quality is easily guaranteed.

[0022] Horizontal pipes can be used to form through-reinforcement pipes after the concrete base slab is assembled, or they can serve as a guide for reinforcing ribs and weight-reducing blocks to ensure the quality of component processing.

[0023] The component installation site does not require the installation and fixing of weight-reducing blocks and the laying of horizontal sleeves. On-site concrete pouring solves the problem of buoyancy of weight-reducing blocks and the problem of unstable concrete pouring under weight-reducing blocks, reducing construction procedures and increasing construction efficiency.

[0024] After on-site assembly, ribbed concrete slabs enable the precast components to be assembled and the structure to be supported with little or no support during the subsequent concrete pouring process. In contrast, the existing construction of cast-in-place concrete slabs with post-tensioned prestressed structures requires waiting until the post-tensioning is completed and the grouting reaches its strength before the support frame and formwork can be removed. This reduces the turnover of the support frame and formwork and affects the construction period.

[0025] The use of weight-reducing blocks effectively reduces the structural self-weight. Because these floor slabs typically have large spans and handle significant live loads, their final thickness is substantial. Without weight-reducing blocks, the slabs would be entirely cast in concrete, resulting in a heavy component, dispersed reinforcement, and numerous pre-drilled holes for reinforcing bars and stiffeners on the precast base slab. This significantly increases construction efficiency and material consumption. By using weight-reducing blocks arranged in a regular, horizontal and vertical pattern, with transverse sleeves placed between blocks perpendicular to the stiffeners, and a horizontal spacing of approximately 500-1000 mm, the reinforcement is more concentrated. The use of post-tensioned prestressed steel increases reinforcement strength while reducing its quantity, resulting in substantial steel savings and reduced on-site reinforcement stringing difficulties.

[0026] Because the floor slab is assembled from precast base plates before concrete is poured to form a whole, the integrity between the precast components is relatively poor. Post-tensioning prestressing is used to generate pre-compression stress between the precast components, increasing the overall integrity of the floor slab and its crack resistance. Since the floor slab is prestressed in both directions after completion, the structural stiffness in both directions is more consistent, and the two-way structural performance is similar, enabling a more effective two-way force-transfer floor slab. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of a two-way prestressed reduced-overlap composite slab structure.

[0028] Figure 2 This is a side elevation diagram of a two-way prestressed reduced-overlap composite slab structure (part of the transverse pipe is embedded in the concrete base slab).

[0029] Figure 3 This is a side elevation diagram of a two-way prestressed reduced-overlap composite slab structure (part of the transverse pipe is laid on the surface of the concrete base slab).

[0030] Figure 4 This is a schematic front cross-section of a bidirectional prestressed reduced-overlap composite slab structure.

[0031] Figure 5 This is a schematic diagram of a two-way prestressed reduced-overlap composite slab structure (double-row transverse pipes).

[0032] Figure 6 This is a side elevation diagram of a two-way prestressed reduced-overlap composite slab structure (with two rows of transverse pipes on the upper surface of the concrete base slab).

[0033] Figure 7 This is a side elevation diagram of a two-way prestressed reduced-overlap composite slab structure (with the double-row transverse pipes embedded in the concrete base slab).

[0034] Figure 8 This is a schematic side cross-section of a bidirectional prestressed weight-reducing prefabricated composite floor slab.

[0035] Figure 9 This is a schematic diagram of the side section of a two-way prestressed weight-reducing prefabricated composite floor slab.

[0036] In the diagram: 1. Precast concrete base slab; 2. Weight reduction block; 3. Reinforcing rib; 4. Longitudinal reinforcing steel; 5. Transverse pipe; 6. Transverse distribution reinforcing steel; 7. Stirrup; 8. Continuous bent corrugated reinforcement. Detailed Implementation

[0037] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0038] Example: Please refer to the appendix. Figure 1-8 This utility model discloses a bidirectional prestressed weight-reducing composite slab, comprising: a precast concrete base slab, weight-reducing blocks, reinforcing ribs, longitudinal reinforcing bars, transverse distributed reinforcing bars, and transverse pipes. The precast concrete base slab contains pre-tensioned prestressed longitudinal reinforcing bars and transverse distributed reinforcing bars; the precast concrete base slab is provided with reinforcing ribs and transverse pipes; the transverse pipes traverse the reinforcing ribs.

[0039] In this embodiment, a new type of composite slab is formed by combining a ribbed concrete base slab, weight-reducing blocks, and transverse sleeves—for bidirectional prestressed weight-reducing prefabricated composite slabs. The component installation site eliminates the need for paving and fixing of weight-reducing blocks and laying of transverse sleeves. On-site concrete pouring solves the problems of buoyancy of the weight-reducing blocks and the tendency for concrete under the weight-reducing blocks to be unstable, reducing construction steps and increasing construction efficiency.

[0040] After on-site assembly, ribbed concrete slabs enable the precast components to be assembled and the structure to be supported with little or no support during the subsequent concrete pouring process. In contrast, the existing construction of cast-in-place concrete slabs with post-tensioned prestressed structures requires waiting until the post-tensioning is completed and the grouting reaches its strength before the support frame and formwork can be removed. This reduces the turnover of the support frame and formwork and affects the construction period.

[0041] The use of weight-reducing blocks effectively reduces the structural self-weight. Because these floor slabs typically have large spans and handle significant live loads, their final thickness is substantial. Without weight-reducing blocks, the slabs would be entirely cast in concrete, resulting in a heavy component, dispersed reinforcement, and numerous pre-drilled holes for reinforcing bars and stiffeners on the precast base slab. This significantly increases construction efficiency and material consumption. By using weight-reducing blocks arranged in a regular, horizontal and vertical pattern, with transverse sleeves placed between blocks perpendicular to the stiffeners, and a horizontal spacing of approximately 500-1000 mm, the reinforcement is more concentrated. The use of post-tensioned prestressed steel increases reinforcement strength while reducing its quantity, resulting in substantial steel savings and reduced on-site reinforcement stringing difficulties.

[0042] Because the floor slab is assembled from precast base plates before concrete is poured to form a whole, the integrity between the precast components is relatively poor. Post-tensioning prestressing is used to generate pre-compression stress between the precast components, increasing the overall integrity of the floor slab and its crack resistance. Since the floor slab is prestressed in both directions after completion, the structural stiffness in both directions is more consistent, and the two-way structural performance is similar, enabling a more effective two-way force-transfer floor slab.

[0043] In this embodiment, the thickness of the prestressed concrete base slab is 45mm~70mm. If the thickness is too thin, it cannot meet the requirements of the reinforcement protective layer and the floor slab to bear the hanging load. If the floor slab is too thick, the self-weight of the floor slab will be too large, which is not conducive to hoisting. The self-weight of the structure will also increase, and the reinforcement and material usage of the floor slab beams and columns will increase.

[0044] In this embodiment, the reinforcing ribs are concrete ribs. The concrete ribs, cast in one piece with the base slab, offer good rigidity and lower cost. This increases the rigidity and flexural strength of the concrete base slab, meeting the requirements for reduced support during component lifting, transportation, hoisting, and construction. Fewer openings between the ribs and the base slab facilitate component fabrication and on-site reinforcement insertion. The concrete ribs are reinforced with stirrups or continuously bent corrugated bars, increasing the shear resistance of the concrete ribs and the concrete base slab, increasing the shear resistance between the cast-in-place concrete and the precast component, and increasing the shear bearing capacity of the composite component.

[0045] In this embodiment, the reinforcing ribs are steel pipe trusses, steel bar trusses, steel pipe web trusses, or concrete truss ribs. The web reinforcement of the reinforcing ribs uses continuously bent steel bars, steel pipes, steel strips, or structural steel. The upper chord uses steel pipes, steel pipe concrete, steel bars, or concrete materials. This increases the stiffness and bending strength of the concrete base slab, meeting the requirements for reduced support during component lifting, transportation, hoisting, and construction. Pre-cast steel ribs facilitate the fabrication of precast base slabs, eliminating the need for secondary rib casting. The pre-cast steel ribs, together with the base slab, form a composite truss, with the prestressed base slab as the lower chord, steel pipes or concrete as the upper chord, and the web reinforcement using steel bars or steel pipes. This allows for thinner precast base slabs with lighter weight, facilitating transportation and hoisting.

[0046] In this embodiment, the reinforcing rib is a composite rib of corrugated steel plate and concrete, with the corrugated steel plate serving as the web and concrete, reinforcing bars, or steel pipes serving as the upper flange. This increases the stiffness and bending strength of the concrete base plate, meeting the requirements for reduced support during component lifting, transportation, hoisting, and construction.

[0047] In this embodiment, the transverse pipe is a metal corrugated pipe. Metal corrugated pipes are easy to obtain and have an irregular surface, which helps to increase the bond strength between the post-tensioned prestressed steel bars, post-grouting and concrete, resulting in better structural performance.

[0048] In this embodiment, the bottom surface of the transverse duct is 5mm to 20mm lower than the top surface of the precast concrete base slab, and part of it is embedded within the precast concrete base slab. This allows for a protective layer thickness of less than 30mm for the post-tensioned prestressed steel reinforcement, increasing the lever arm of the post-tensioned prestressed steel reinforcement, improving the load-bearing capacity of the component, and reducing steel consumption. Maintaining consistency with the design model parameters reduces the workload of recalculating and verifying the design.

[0049] In this embodiment, the transverse pipe rests on the surface of the precast concrete base slab and is fixed to the base slab. The transverse pipe is fixed on site and is used to form a reserved pipe after the concrete is poured. Reinforcing bars are inserted and grout is injected to form bonded post-tensioned prestress.

[0050] In this embodiment, multiple transverse pipes are arranged perpendicular to the longitudinal reinforcing bars, with a spacing of not less than 500mm. Increasing the spacing of the transverse pipes appropriately facilitates component fabrication and reduces the number of reinforcing bars inserted. While increasing the spacing increases the calculated amount of reinforcing bars, using post-inserted prestressed reinforcing bars allows for better utilization of material properties.

[0051] In this embodiment, the weight-reducing block is a steel mesh box, a lightweight membrane shell, or a foam board. Using hollow or lightweight materials to replace concrete, which bears less stress, saves concrete usage and reduces the structure's self-weight. It also serves as lateral formwork for the cast-in-place concrete ribs. After the concrete is poured, a two-way concrete ribbed floor slab is formed.

[0052] In this embodiment, the weight-reducing block is cast integrally with the pre-tensioned prestressed concrete base slab and pre-assembled in the factory, which improves on-site installation efficiency and saves construction time. It also avoids the problems of the weight-reducing block floating during concrete pouring and the problem of insufficient compaction of the concrete directly beneath the weight-reducing block.

[0053] In this embodiment, the weight-reducing blocks are set in the area enclosed by the reinforcing ribs and the transverse pipes. The reinforcing ribs and the transverse pipes form orthogonal gaps, which form concrete ribs after the concrete is poured, and finally form a two-way dense rib floor slab.

[0054] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A bidirectional prestressed reduced-overlap composite slab, characterized in that, It includes: The precast concrete base slab (1), weight reduction block (2), reinforcing rib (3), longitudinal reinforcing bar (4), transverse distribution reinforcing bar (6), and transverse pipe (5) are provided inside the precast concrete base slab (1); the precast concrete base slab (1) is provided with prestressed longitudinal reinforcing bar (4) and transverse distribution reinforcing bar (6); the precast concrete base slab (1) is provided with reinforcing rib (3) and transverse pipe (5); the transverse pipe (5) passes through the reinforcing rib (3).

2. The bidirectional prestressed reduced-overlap composite slab according to claim 1, characterized in that: The thickness of the precast concrete base plate (1) is 45mm~70mm.

3. The bidirectional prestressed reduced-overlap composite slab according to claim 1, characterized in that: The reinforcing rib (3) is a concrete rib, which is cast in one piece with the precast concrete base plate.

4. The bidirectional prestressed reduced-overlap composite slab according to claim 3, characterized in that: The concrete rib is provided with stirrups (7).

5. A bidirectional prestressed reduced-overlap composite slab according to claim 3, characterized in that: The concrete rib is provided with continuous bent corrugated bars (8).

6. The bidirectional prestressed reduced-overlap composite slab according to claim 1, characterized in that: The reinforcing rib (3) is a steel pipe truss, steel bar truss, steel pipe web truss, or concrete truss rib.

7. The bidirectional prestressed reduced-overlap composite slab according to claim 1, characterized in that: The reinforcing rib (3) is a combination of corrugated steel plate and concrete, with the corrugated steel plate as the web and concrete, steel bars, or steel pipes as the upper flange.

8. A bidirectional prestressed reduced-overlap composite slab according to claim 1, characterized in that: The longitudinal reinforcing steel bar (4) is a prestressed steel bar.

9. A bidirectional prestressed reduced-overlap composite slab according to claim 1, characterized in that: The transverse pipe (5) is a metal corrugated pipe.

10. A bidirectional prestressed reduced-overlap composite slab according to claim 1, characterized in that: The bottom surface of the transverse pipe (5) is 5mm~20mm lower than the upper surface of the precast concrete base plate (1), and part of it is embedded in the precast concrete base plate.

11. A bidirectional prestressed reduced-overlap composite slab according to claim 1, characterized in that: The transverse pipe (5) rests on the surface of the precast concrete base plate (1) and is fixed to the precast concrete base plate.

12. A bidirectional prestressed reduced-overlap composite slab according to claim 1, characterized in that: The transverse pipes (5) are perpendicular to the longitudinal reinforcing bars (4) and are arranged in multiple sections with a spacing of not less than 500 mm.

13. A bidirectional prestressed reduced-overlap composite slab according to claim 1, characterized in that: The weight-reducing block (2) is a steel wire mesh box, a lightweight membrane shell, or a foam board.

14. A bidirectional prestressed reduced-overlap composite slab according to claim 1, characterized in that: The weight-reducing block (2) is cast as a whole with the precast concrete base plate (1).

15. A bidirectional prestressed reduced-overlap composite slab according to claim 1, characterized in that: The weight-reducing block (2) is placed on the precast concrete base plate (1) and fixed to the precast concrete base plate.

16. A bidirectional prestressed reduced-overlap composite slab according to claim 1, characterized in that: The weight-reducing block (2) is set in the area enclosed by the reinforcing rib (3) and the transverse pipe (5).

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