U-shaped concrete superposed beam

Abstract

The utility model discloses a U-shaped concrete superposed beam. The U-shaped concrete superposed beam comprises a concrete bottom plate, concrete side walls, inner formworks, tie bars, longitudinal load-bearing steel bars and stirrups. The concrete side walls are arranged on the two sides of the concrete bottom plate. The inner mold sheet is arranged on the inner side of the concrete side wall; the tie bars are anchored in the concrete side wall end to end and arranged in the length direction of the concrete side wall. The longitudinal load-bearing steel bars are embedded in the concrete bottom plate and sleeved with the stirrups. And the stirrup part is embedded in the concrete side wall or the concrete bottom plate. According to the U-shaped concrete composite beam, one-time pouring forming of the U-shaped concrete composite beam is achieved through the inner formwork and the tie bars, manufacturing is convenient, the integrality of a prefabricated part is good, the rigidity in the later period is large, and bonding of composite concrete and prefabricated concrete is better. The composite beam prefabricated part is lighter in weight, free of molds and supports and convenient to transport and install.

Description

Technical Field

[0001] The utility model relates to the technical field of engineering, in particular to a U-shaped concrete composite beam which can be widely used in beams of various projects. Background Art

[0002] The technology of prefabricated composite beams is widely used. Currently, the most widely used type on the market is the solid composite beam, which is characterized by a large amount of precast concrete, which can save on formwork and reduce support. However, due to the large cross-section and heavy concrete weight, transportation and installation efficiency are often low, and the cost is actually higher than that of existing cast-in-place structures. Many people have also considered using trough-type composite beams, but due to the complex reinforcement in existing trough-type composite beams, the cost of the inner formwork is high, and the production is difficult. Production requires two or three pours of concrete, and the process is complicated. In addition, the rigidity and strength of prefabricated components are insufficient, and supports cannot be reduced during construction. The final project cost is high, making it difficult to apply and promote.

[0003] A prefabricated U-shaped composite beam (Patent No. CN 207017528 U) proposes using concrete wrapped around U-shaped steel plates to create a U-shaped steel-reinforced concrete composite beam. This technology welds anchor bars to the U-shaped steel plates and steel mesh within the concrete to form a stable stirrup. This technology makes the composite beam lightweight, easy to transport and install, and reduces transportation and installation costs. However, the welding of anchor bars to the steel plates and steel mesh requires significant welding effort and energy consumption, leading to high prefabrication costs. The principle is to wrap concrete around U-shaped steel plates to form a U-shaped steel-reinforced concrete composite beam. This technology also does not address the issue of simultaneous casting of the ribs and base plate. Relying on U-shaped steel to increase the strength and rigidity of the composite beam is costly and ineffective.

[0004] A prefabricated, cast-in-place, monolithic reinforced concrete composite beam (Patent No. CN 203213396 U) proposes a U-shaped prefabricated composite beam with a roughened inner wall and a cast-in-place T-shaped cross-section, forming a single unit with the roughened surface. Compared to prefabricated and assembled structures, this technology significantly improves structural integrity and enhances seismic performance. Furthermore, the number of formwork required during construction is significantly reduced compared to cast-in-place reinforced concrete structures, significantly accelerating construction and effectively shortening the project schedule. However, the fabrication of the prefabricated components using this technology is complex. Due to the complex relationship between the structural reinforcement, longitudinal tension reinforcement, and stirrups in the beam, this technology requires two pours, making it difficult to implement. Furthermore, due to the thin sidewalls and baseplate, the prefabricated components have low stiffness, and the sidewalls themselves are weak in stability, requiring support and lateral tensioning during on-site construction. Summary of the Invention

[0005] To this end, the present invention proposes a U-shaped concrete composite beam to solve the problems raised in the above background technology.

[0006] To achieve the above objectives, the present invention discloses a U-shaped concrete composite beam comprising: a concrete base plate, concrete sidewalls, an inner formwork, tie bars, longitudinal stress-bearing steel bars, and stirrups. The concrete sidewalls are disposed on either side of the concrete base plate; the inner formwork is disposed inside the concrete sidewalls; the tie bars are anchored end to end within the concrete sidewalls and arranged along the length of the concrete sidewalls; the longitudinal stress-bearing steel bars are embedded within the concrete base plate and encased within the stirrups; and the stirrups are partially embedded within the concrete sidewalls or the concrete base plate.

[0007] Furthermore, preferably, the inner formwork is permanently placed on the inner side of the concrete side wall, with the bottom edge close to the lower surface of the concrete bottom plate.

[0008] Furthermore, preferably, a small notch is provided on the bottom edge of the inner mold piece, the small notch is slightly larger than the diameter of the stirrup, and the stirrup passes through the small notch.

[0009] Furthermore, preferably, the inner side of the concrete side wall is provided with vertical ribs.

[0010] Furthermore, preferably, the inner mold piece has vertical ribs bent longitudinally, corresponding to the vertical ribs.

[0011] Furthermore, preferably, an outer longitudinal rib is provided on the outer side of the top of the concrete side wall.

[0012] Furthermore, preferably, an inner longitudinal rib is provided on the inner side of the top of the concrete side wall.

[0013] Furthermore, preferably, the inner mold piece has horizontal ribs bent longitudinally, corresponding to the inner longitudinal ribs.

[0014] Furthermore, as a preference, waist longitudinal steel bars are provided in the concrete side walls, and the waist longitudinal steel bars are arranged vertically in the concrete side walls.

[0015] Furthermore, preferably, the longitudinal steel bars at the waist are prestressed steel bars.

[0016] Furthermore, as a preference, the waist longitudinal reinforcement is located outside the stirrups and is tied together with the stirrups and tension bars.

[0017] Furthermore, preferably, a post-tensioned prestressed pipe is provided between the concrete side wall and the concrete bottom plate.

[0018] Furthermore, preferably, the post-tensioned prestressed pipe is in the shape of a curve, a broken line or a straight line.

[0019] Furthermore, preferably, the longitudinal stress-bearing steel bars are prestressed steel strands or non-prestressed steel bars or a combination of prestressed steel bars and non-prestressed steel bars.

[0020] Furthermore, preferably, the inner mold sheet is a steel mesh or a thin steel sheet with indentations.

[0021] Furthermore, preferably, steel bars are laid on the upper portion of the concrete base plate.

[0022] Furthermore, preferably, the stirrups are welded closed stirrups.

[0023] Furthermore, preferably, the thickness of the concrete base plate is 40-300 mm.

[0024] This utility model utilizes the above technology and has the following advantages compared to existing technologies: Concrete sidewalls are cast simultaneously with the base plate, simplifying the manufacturing process. The sidewalls have a high inherent stability strength, meeting the strength requirements of post-cast concrete. The precast components have high rigidity and strength, enabling support-free construction. The precast components are lighter, resulting in improved structural integrity and seismic performance. Construction and installation avoid rebar conflicts, are lightweight, and require no supports or formwork, resulting in simple, efficient, and time-saving construction.

[0025] The use of an inner formwork, with its lower edge close to the bottom of the base slab, mitigates the pressure differential between the concrete pouring of the sidewalls and base slab, enabling a single pour. Furthermore, the inner formwork is a permanent metal formwork, enhancing the shear resistance of the precast component and its bond with the composite concrete. A small notch in the bottom edge of the inner formwork, through which stirrups pass, secures the stirrups during fabrication and mitigates the pressure differential between the sidewall and base slab concrete during pouring, enabling a single pour of the sidewall and base slab concrete.

[0026] The inner side of the concrete sidewalls is formed of vertical ribs. Bending the inner formwork increases the rigidity of the inner formwork, meeting the requirements for sidewall casting. This also reduces the overall thickness of the sidewalls, creating a thin-plate ribbed effect: the sidewalls are locally thickened while remaining thinner in most areas. This localized thickening involves widening the beam formwork and inner formwork in certain locations to facilitate concrete pouring during sidewall construction. The concave and convex curves on the inner side of the sidewalls increase the contact surface between the precast components and the composite concrete, further ensuring that the overall performance of the composite components is closer to that of cast-in-place concrete.

[0027] The top of the concrete sidewall is partially thickened outward to form longitudinal ribs that protrude from the sidewall. This thickens the upper edge of the precast component, increasing its bending moment of inertia and, consequently, its strength and rigidity. This outward protrusion also facilitates the placement of precast composite slabs, enabling construction without formwork or support. The protruding sidewall ribs also facilitate the pouring of concrete during the precast component's molding.

[0028] The top of the concrete sidewall is locally thickened inward, protruding from the inside of the sidewall to form an inner longitudinal rib. Thickening the upper edge of the precast component can increase the precast component's bending moment of inertia, thereby increasing the component's strength and rigidity. The protruding sidewall ribs also facilitate the pouring of concrete during the precast component's molding.

[0029] The concrete sidewalls are equipped with longitudinal reinforcement at the waist, arranged vertically within the concrete sidewalls. Prestressed longitudinal reinforcement improves the precast component's crack and torsional strength while reducing steel usage. Positioned outside the stirrups, the longitudinal reinforcement is tied together with the stirrups and tie bars, allowing the two concrete sidewalls to form a single unit through the tie bars. This enhances the anchoring strength of the tie bars and meets the lateral strength requirements of the composite concrete pour.

[0030] Post-tensioned prestressed pipes are installed between the concrete side walls and the concrete bottom plate. The post-tensioned prestressed pipes are generally metal bellows. After the composite concrete is poured, metal bellows are reserved in the beam to pass through prestressed steel strands, thereby improving the strength of the composite components, greatly reducing the amount of steel used in the structure, and increasing the seismic performance of the structure.

[0031] The longitudinal force-bearing reinforcement in the concrete base plate adopts prestressed steel strands, which can reduce the amount of steel used, improve the strength of prefabricated components, and meet the strength requirements of unsupported components during composite concrete pouring.

[0032] The inner formwork is a steel mesh or a thin steel sheet with indentations, which can not only reduce the material consumption of the inner formwork, but also strengthen the connection between the prefabricated components and the composite concrete. The exposed cement slurry of the steel mesh can form a rough contact surface between the new and old concrete.

[0033] Rebar is laid on the upper portion of the concrete baseplate, placing some load-bearing reinforcement within the precast components and some within the composite concrete. This reduces the amount of reinforcement used in the precast components, mitigates steel clashes, and facilitates installation. The subsequent reinforcement is non-prestressed, meeting the seismic requirements of the components. A linear groove is reserved in the baseplate, allowing the subsequent reinforcement to be placed closer to the bottom of the component, resulting in a thinner protective layer, reducing steel usage and increasing component strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic diagram of the inner formwork of a U-shaped concrete composite beam Figure 1 ;

[0035] Figure 2 Schematic diagram of the inner formwork of a U-shaped concrete composite beam Figure 2 ;

[0036] Figure 3 Schematic diagram of the inner formwork of a U-shaped concrete composite beam Figure 3 ;

[0037] Figure 4Schematic diagram of the inner formwork of a U-shaped concrete composite beam Figure 4 ;

[0038] Figure 5 A schematic diagram of the relationship between the reinforcement and the inner formwork of a U-shaped concrete composite beam;

[0039] Figure 6 A schematic diagram of a U-shaped concrete composite beam Figure 1 ;

[0040] Figure 7 A schematic diagram of a U-shaped concrete composite beam Figure 2 ;

[0041] Figure 8 A schematic diagram of a U-shaped concrete composite beam Figure 3 ;

[0042] Figure 9 A schematic diagram of a U-shaped concrete composite beam Figure 4 ;

[0043] Figure 10 A schematic diagram of a U-shaped concrete composite beam Figure 5 ;

[0044] Figure 11 A schematic diagram of a U-shaped concrete composite beam Figure 6 ;

[0045] Figure 12 This is a schematic diagram of the AA section of a U-shaped concrete composite beam;

[0046] Figure 13 A schematic diagram of a U-shaped concrete composite beam Figure 7 ;

[0047] Figure 14 This is a schematic diagram of the BB section of a U-shaped concrete composite beam;

[0048] Figure 15 This is a schematic cross-sectional view of a U-shaped concrete composite beam (with post-tensioning).

[0049] In the figure: 1. Concrete base plate; 2. Concrete side walls; 2-1. Vertical ribs; 2-2. Outer longitudinal ribs; 2-3. Inner longitudinal ribs; 3. Inner formwork; 3-1. Small notch; 3-2. Vertical ribs; 3-3: Horizontal ribs; 4. Tie bars; 5. Longitudinal stress-bearing steel bars; 6. Stirrups; 7. Waist longitudinal steel bars; 8. Steel bars; 9. Post-tensioned prestressed pipes. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0051] Example 1: Please refer to the attached Figure 1-15 The present invention provides a technical solution comprising a concrete base plate, concrete side walls, an inner formwork, tie bars, longitudinal stress-bearing steel bars, and stirrups. The concrete side walls are arranged on both sides of the concrete base plate; the inner formwork is arranged inside the concrete side walls; the tie bars are anchored at both ends within the concrete side walls and arranged along the length of the concrete side walls; the longitudinal stress-bearing steel bars are embedded within the concrete base plate and encased within the stirrups; and the stirrups are partially embedded within the concrete side walls or the concrete base plate.

[0052] Furthermore, the inner mold piece is permanently placed on the inner side of the concrete side wall, with the bottom edge close to the lower surface of the concrete bottom plate.

[0053] Furthermore, the concrete side walls are provided with waist longitudinal steel bars, and the waist longitudinal steel bars are arranged vertically in the concrete side walls.

[0054] Furthermore, the longitudinal steel bars at the waist are prestressed steel bars.

[0055] Furthermore, the waist longitudinal reinforcement is located outside the stirrups and is tied together with the stirrups and the tension bars.

[0056] Furthermore, the inner mold piece is a steel mesh or a thin steel sheet with indentations.

[0057] Furthermore, steel bars are laid on the upper portion of the concrete base plate.

[0058] Furthermore, a post-tensioned prestressed pipe is provided between the concrete side wall and the concrete bottom plate.

[0059] Furthermore, the post-tensioned prestressed pipe is in the shape of a curve, a broken line or a straight line.

[0060] Furthermore, the stirrups are welded closed stirrups.

[0061] Furthermore, the thickness of the concrete base plate is 40-300 mm.

[0062] Example 2: It is basically the same as Example 1, except that a small notch is opened at the bottom edge of the inner mold piece. The small notch is slightly larger than the diameter of the stirrup, and the stirrup passes through the small notch. Figure 5

[0063] Example 3: It is basically the same as Examples 1 and 2, except that vertical ribs are provided in the concrete side walls. Figure 3 、 10 .

[0064] Furthermore, the inner mold piece has vertical ribs bent longitudinally, corresponding to the vertical ribs.

[0065] Example 4: It is basically the same as Examples 1, 2, and 3, except that an outer longitudinal rib is provided on the outer side of the top of the concrete side wall. Figure 2 、 7 .

[0066] Example 5: It is basically the same as Examples 1, 2, and 3, except that an inner longitudinal rib is provided on the inner side of the top of the concrete side wall. Figure 4 、 5 、8.

[0067] Furthermore, the inner mold piece has horizontal ribs bent longitudinally, corresponding to the inner longitudinal ribs.

[0068] Although the 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 variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A U-shaped concrete composite beam, characterized in that: It comprises: a concrete base plate (1), a concrete side wall (2), an inner formwork (3), a tie bar (4), longitudinal stress-bearing steel bars (5) and stirrups (6); the concrete side wall (2) is arranged on both sides of the concrete base plate (1); the inner formwork (3) is arranged on the inner side of the concrete side wall (2); the tie bar (4) is anchored at both ends in the concrete side wall (2) and arranged along the length direction of the concrete side wall (2); the longitudinal stress-bearing steel bars (5) are embedded in the concrete base plate (1) and are sheathed in the stirrups (6); and the stirrups (6) are partially embedded in the concrete side wall (2) or the concrete base plate (1).

2. A U-shaped concrete composite beam according to claim 1, characterized in that: The inner mold piece (3) is permanently placed on the inner side of the concrete side wall (2), with the bottom edge close to the lower surface of the concrete bottom plate (1).

3. The U-shaped concrete composite beam according to claim 1, characterized in that: A small notch (3-1) is provided on the bottom edge of the inner mold piece (3), the small notch (3-1) being slightly larger than the diameter of the stirrup (6), and the stirrup (6) passes through the small notch (3-1).

4. The U-shaped concrete composite beam according to claim 1, characterized in that: Vertical ribs (2-1) are provided in the concrete side wall (2).

5. The U-shaped concrete composite beam according to claim 1, characterized in that: The inner mold piece (3) has vertical ribs (3-2) bent longitudinally, corresponding to the vertical ribs (2-1).

6. The U-shaped concrete composite beam according to claim 1, characterized in that: External longitudinal ribs (2-2) are provided on the outer side of the top of the concrete side wall (2).

7. The U-shaped concrete composite beam according to claim 1, characterized in that: Inner longitudinal ribs (2-3) are provided on the inner side of the top of the concrete side wall (2).

8. The U-shaped concrete composite beam according to claim 1, characterized in that: The inner mold piece (3) has longitudinally bent horizontal ribs (3-3) corresponding to the inner longitudinal ribs (2-3).

9. The U-shaped concrete composite beam according to claim 1, characterized in that: Waist longitudinal steel bars (7) are provided in the concrete side wall (2), and the waist longitudinal steel bars (7) are arranged vertically on the concrete side wall.

10. The U-shaped concrete composite beam according to claim 9, characterized in that: The waist longitudinal steel bars (7) are prestressed steel bars.

11. The U-shaped concrete composite beam according to claim 9, characterized in that: The waist longitudinal steel bars (7) are located outside the stirrups (6) and are tied together with the stirrups (6) and the tension bars (4).

12. The U-shaped concrete composite beam according to claim 1, characterized in that: A post-tensioned prestressed pipe (9) is provided between the concrete side wall (2) and the concrete bottom plate (1).

13. The U-shaped concrete composite beam according to claim 12, characterized in that: The post-tensioned prestressed pipe (9) is in the shape of a curve, a broken line or a straight line.

14. The U-shaped concrete composite beam according to claim 1, characterized in that: The longitudinal stress-bearing steel bars (5) are prestressed steel strands or non-prestressed steel bars or a combination of prestressed steel bars and non-prestressed steel bars.

15. The U-shaped concrete composite beam according to claim 1, characterized in that: The inner mold piece (3) is a steel mesh or a thin steel sheet with indentations.

16. The U-shaped concrete composite beam according to claim 1, characterized in that: Steel bars (8) are laid on the upper part of the concrete base plate (1).

17. The U-shaped concrete composite beam according to claim 1, characterized in that: The stirrups (6) are welded closed stirrups.

18. The U-shaped concrete composite beam according to claim 1, characterized in that: The thickness of the concrete base plate (1) is 40-300 mm.

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