Shear connector, steel-concrete composite beam comprising the shear connector, and construction method thereof

Abstract

The application discloses a shear connector, a steel-concrete composite beam containing the shear connector and a construction method of the steel-concrete composite beam. The shear connector comprises an inverted truncated cone type cylinder (7), a stiffener, a cover plate, a penetrating steel bar (8) and a high-strength bolt (21); the stiffener comprises an integrally formed stiffener bottom plate (13) and a stiffener side plate (14), the size of the stiffener bottom plate is consistent with the size of the lower opening of the cylinder, and the stiffener bottom plate is attached to the lower opening of the cylinder; the stiffener bottom plate is provided with a second connecting hole for connecting the high-strength bolt; the stiffener side plate is arranged around the stiffener bottom plate and is attached to the inner wall of the cylinder; the height of the stiffener side plate is lower than that of the first connecting hole; the cover plate covers the upper opening of the cylinder; the penetrating steel bar transversely passes through the cylinder through the first connecting hole and leaves a connecting section on each side of the cylinder; and the high-strength bolt connects the stiffener bottom plate through the second connecting hole. The application realizes the disassembly and replacement of each component of the shear connector and the prefabricated bridge deck; and the structure form and stress performance of the shear connector are optimized.

Description

Technical Field

[0001] This invention relates to steel-concrete composite beams in the fields of bridges and building construction, and in particular to a shear connector, a steel-concrete composite beam containing the shear connector, and a construction method thereof. Background Technology

[0002] Steel-concrete composite bridge structures integrate steel beams and concrete bridge decks using shear connectors, fully utilizing the strengths of steel (suitable for tension) and concrete (suitable for compression). This improves the overall structural load-bearing capacity and economy, resulting in superior mechanical properties and significant technical and economic benefits. They are widely used in bridge and building construction both domestically and internationally. However, influenced by factors such as technological level, construction methods, and raw materials, steel-concrete composite beams still suffer from issues such as low assembly density due to complex structural design, and insufficient shear force transfer and ductility at the steel-concrete joint. Overcoming these shortcomings through optimized design and more efficient construction methods remains a key challenge.

[0003] The steel-concrete composite section is a critical part of the steel-concrete composite structure, with a complex force transmission mechanism. Its stress performance directly affects the safety and reliability of the structure, easily leading to localized stress concentration and structural failure. Connectors are typically required to meet the functional requirements of resisting shear forces and vertical uplift forces. Traditional shear connectors can be broadly classified into four categories: stud connectors, profiled steel connectors, bent-rib connectors, and perforated steel plate connectors (PBL connectors), most of which are fixed to the steel beams by welding. In contrast, using detachable shear connectors offers several significant advantages: First, it can improve project progress and quality by reducing welding procedures, thus increasing construction efficiency and quality; second, it can reduce maintenance costs and cycles, facilitating connector replacement; third, it can improve the reusability of the bridge structure; and finally, it can ensure the quality and reliability of the connectors, improving the safety of the bridge structure. These advantages enhance the reliability and durability of the bridge structure while bringing greater convenience to bridge maintenance and upgrades. To enhance the shear strength of steel-concrete composite structures in different directions, increase structural stiffness and strength, and ensure a good combination effect between steel and concrete, it is necessary to continuously explore and optimize the construction form of shear connectors.

[0004] Compared to ordinary concrete bridge decks, UHPC bridge decks offer numerous advantages, including high strength, durability, lightweight, ease of construction, and aesthetic appeal. The high strength of UHPC bridge decks allows for designs requiring high strength and high structural efficiency, while also reducing the cross-sectional dimensions and weight of the bridge structure. Their excellent impermeability, freeze-thaw resistance, and chemical resistance enable long-term use in harsh climates and environments, preventing cracking and peeling caused by chloride ions and other chemicals. Their lightweight nature reduces the self-weight of the bridge deck and the amount of material used, further lowering the overall weight of the bridge structure. Rapid installation and dismantling shorten construction time and minimize the impact on the surrounding environment. Finally, their aesthetic appeal allows for adjustments to color and texture according to design requirements, enhancing the bridge's visual appeal and overall appearance. Therefore, UHPC bridge decks are widely used in bridge and building construction.

[0005] A channel steel beam is a box girder with an open upper edge, consisting of parallel upper and lower steel plates and a pair of vertical webs between them. Made of steel, channel steel beams are lighter than concrete beams, reducing the structure's self-weight and thus lowering construction costs. Their rational cross-sectional shape, high moment of inertia, and large cross-sectional area give them excellent resistance to bending, shear, and torsion, resulting in high structural strength and stability. Furthermore, channel steel beams are relatively easy to manufacture and process, with mature manufacturing techniques that allow for fabrication, assembly, and disassembly through a series of steps. They can also be connected by bolts or welding, facilitating construction and maintenance. This connection method allows for easy disassembly, replacement, or adjustment of the main channel steel beam during maintenance or renovation, reducing the difficulty and cost of maintenance and renovation.

[0006] In view of this, the inventors of this application have developed a shear connector, a steel-concrete composite beam containing the shear connector, and a construction method thereof, in order to overcome some shortcomings of traditional steel-concrete composite structures and obtain better structural forms and mechanical properties. Summary of the Invention

[0007] The technical problem to be solved by this invention is to address the shortcomings and areas for improvement of the traditional steel-concrete composite structure, and to provide a shear connector, a steel-concrete composite beam containing the shear connector, and a construction method thereof, so as to achieve the detachability and performance improvement of the shear connector in the steel-concrete composite beam, the optimization of the mechanical properties and durability of the precast bridge deck, the reduction of the self-weight of the steel beam and the improvement of its bending, shear and torsional resistance, and the simplification of the construction process and the reduction of construction and maintenance costs while the composite beam has high structural strength and stability.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a shear connector, comprising a frustum-shaped cylinder, a stiffener placed inside the cylinder, a cover plate covering the top of the cylinder, a through-bar rebar extending transversely through the cylinder, and a high-strength bolt installed on the stiffener; the cylinder has a large upper opening and a small lower opening, and a first connecting hole is provided at the upper part of the cylinder; the stiffener comprises an integrally formed stiffening base plate and a stiffening side plate, the size of the stiffening base plate being the same as the size of the lower opening of the cylinder and fitting against the lower opening of the cylinder, a second connecting hole being provided on the stiffening base plate, the stiffening side plate being arranged around the stiffening base plate and fitting against the inner wall of the cylinder, and the height of the stiffening side plate being lower than the first connecting hole; the cover plate covering the upper opening of the cylinder; the through-bar rebar extending transversely through the first connecting hole through the cylinder, and having connecting sections on both sides of the cylinder; the high-strength bolt connecting to the stiffening base plate through the second connecting hole.

[0009] Furthermore, the stiffening side plates are multiple pieces, evenly distributed around the stiffening base plate, and telescopic connecting rods connect the opposing stiffening side plates.

[0010] Furthermore, the telescopic connecting rod includes a sleeve and a connecting screw. One end of the sleeve is connected to one end of the connecting screw by a threaded connection, and the other end of the sleeve is hinged to the stiffening side plate. The other end of the connecting screw is configured as a spherical head, and a fixed sleeve with a spherical cavity is installed on the stiffening side plate. The spherical head of the connecting screw is connected to the spherical cavity of the fixed sleeve to form a spherical rotary joint.

[0011] Furthermore, the cylindrical body is a frustum shape.

[0012] Furthermore, a stop is provided at the top of the inner wall of the cylinder to support the cover plate.

[0013] Furthermore, a lifting ring is provided on the top surface of the cover plate.

[0014] Based on the same inventive concept, the present invention also provides a steel-concrete composite beam including the shear connector, which includes a channel steel beam, a shear connector, and a precast bridge deck. The channel steel beam includes an upper flange steel plate, a web steel plate and a bottom steel plate. The web steel plate is respectively provided on both sides of the bottom steel plate. One end of the web steel plate is connected to the bottom steel plate and the other end is connected to the upper flange steel plate.

[0015] A third connecting hole is provided on the upper flange steel plate on both sides of the bottom steel plate. A slot corresponding to the connecting hole on the upper flange steel plate is reserved on the precast bridge panel. The top surface of the upper flange steel plate is in contact with the bottom surface of the precast bridge panel. A cast-in-place groove is formed between the inner wall of the slot and the top surface of the upper flange steel plate.

[0016] The shear connector is placed in the cast-in-place trough, and the two ends of the through steel bar are respectively connected to the structural steel bars of the precast bridge deck. The stiffening bottom plate and the upper flange steel plate are fixedly connected by the high-strength bolts passing through the third connecting hole. The cast-in-place concrete is poured in the cast-in-place trough.

[0017] Furthermore, third connecting holes are symmetrically arranged on the upper flange steel plates on both sides of the bottom steel plate relative to the longitudinal central axis of the channel steel beam.

[0018] Furthermore, the through reinforcing bars are arranged transversely parallel to the channel-shaped steel beam.

[0019] Based on the same inventive concept, the present invention also provides a construction method for the aforementioned steel-concrete composite beam, comprising:

[0020] First, the prefabricated bridge deck is hoisted onto the top surface of the upper flange steel plate of the channel steel beam, and the reserved slots on the prefabricated bridge deck are aligned with the reserved connection holes on the upper flange steel plate.

[0021] Then, the cylinder with the stiffened bottom plate is placed on the upper flange steel plate. The second connection hole reserved on the stiffened bottom plate corresponds to the third connection hole on the upper flange steel plate. Then, the shear connector is fixed to the upper flange steel plate with high-strength bolts at the second connection hole and the third connection hole. At the same time, through steel bars are configured and the top cover plate is installed.

[0022] After the shear connector is installed, the through steel bar and the structural steel bar of the precast bridge deck are connected by steel bar sleeve. Then, concrete filling material is poured into the cast-in-place trench, and construction is carried out at the joint of adjacent precast bridge decks. The construction is then completed.

[0023] Both the bottom steel plate and the belly steel plate are provided with stiffening ribs. The stiffening ribs of the bottom steel plate are arranged on the upper surface of the bottom plate in the form of longitudinal arrangement along the channel steel beam. The stiffening ribs of the belly steel plate are arranged on the inner side of the belly steel plate, and the belly steel plate is reinforced in a cross arrangement of transverse and vertical arrangement. The stiffening ribs and the corresponding steel plates are rigidly connected by welding.

[0024] The aforementioned steel-concrete composite beam with shear connectors combines the upper UHPC slab (preferably a precast bridge deck) with the lower channel steel beam via shear connectors. The lightweight UHPC slab structure exhibits high ductility, reduces the self-weight of the concrete bridge deck structure, lowers the risk of cracking, and provides higher durability, thus enhancing the span capacity of the composite beam. The channel steel beam is lightweight and high-strength, can be prefabricated in a factory, and its manufacturing process is relatively simple, improving construction efficiency. During assembly and installation, the precast bridge deck (UHPC slab) is first hoisted onto the top surface of the upper flange steel plate of the channel steel beam, and the pre-drilled slots on the precast bridge deck are aligned with the slots pre-drilled on the upper flange steel plate. The third connecting hole is positioned accordingly. Then, the cylinder with the stiffened base plate is placed on the upper flange steel plate. The second connecting hole reserved on the base plate of the shear connector corresponds to the third connecting hole on the upper flange steel plate of the channel steel beam. Then, the shear connector is fixed to the upper flange steel plate at the second and third connecting holes with high-strength bolts. Subsequently, through-bar reinforcement is installed and the top cover plate is installed. After the connector is installed, the through-bar reinforcement is connected to the structural reinforcement of the precast bridge deck through the reinforcement sleeve. Then, concrete filling material is poured in the cast-in-place trench, and the construction of the joint of the precast bridge deck is carried out at the same time, thereby completing the construction of the UHPC-channel steel composite beam with the shear connector.

[0025] To replace the shear connector, loosen the nut below the shear connector from the bottom of the upper flange steel plate, remove the concrete from the top of the shear connector in the cast-in-place trench, lift the top cover plate with the folding lifting ring, cut the through reinforcement, clean the residual concrete near the first connection hole on the shear connector, tighten the telescopic connecting rod to reduce the bending angle of the stiffening side plate, achieving the effect of separating the stiffening side plate from the cylinder, and then lift the telescopic connecting rod to allow the stiffening bottom plate to be removed smoothly. Subsequently, the cylinder, stiffening bottom plate, and high-strength bolts can be disassembled and replaced according to the actual situation. If it is necessary to replace the precast bridge deck components, remove the shear connector and remove the concrete in the joint of the precast bridge deck. After cutting the lapped reinforcement at the joint of the bridge deck with a cutting tool, the precast bridge deck components can be disassembled and replaced.

[0026] Therefore, the steel-concrete composite beam with shear connectors can be disassembled and replaced, and the precast bridge deck can be replaced. This improves the performance of the precast bridge deck, enhances the bending, shear, and torsional resistance of the channel steel beam, and enables prefabricated construction, thereby improving the efficiency of engineering construction.

[0027] Furthermore, the shear connector is arranged along the longitudinal central axis of the channel steel beam in the form of through steel bars parallel to the transverse direction of the channel steel beam. When subjected to external forces, the cylinder is mainly used to resist the horizontal shear forces in various directions on the composite beam. The cylinder is an inverted frustum-shaped cylinder with a large upper opening and a small lower opening. This design allows the outer wall of the cylinder to resist the horizontal shear force while also constraining the vertical lifting of the concrete slab, so that the shear connector achieves the dual function of resisting shear and pulling.

[0028] Furthermore, the through-bar is a ribbed bar, which will form a concrete tenon at the first connecting hole of the cylinder after concrete is poured in the cast-in-place trench; when subjected to external force, the through-bar and the concrete tenon in the first connecting hole work together to resist the longitudinal horizontal shear force of the steel beam, and can also play a role in resisting pull-out.

[0029] Furthermore, the channel steel beams are manufactured in the factory using precise machines and equipment for cutting, drilling, welding, and other processing steps to ensure the dimensional accuracy and quality control of the channel steel beams.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0031] I. The shear connector of this invention combines the advantages of steel profile connectors and PBL connectors. The inverted frustum-shaped cylinder resists horizontal shear forces, while its inverted frustum design with a large upper opening and a small lower opening resists the vertical uplift force of the concrete slab. The through-bar rebar runs horizontally through the cylinder and forms a concrete tenon at the first connection hole after concrete pouring, which also resists both horizontal shear forces and vertical uplift forces. The combined effect of these two components enhances the shear strength of the steel-concrete composite structure in different directions, reduces the shear slippage of the connector, thereby increasing the stiffness and strength of the structure and achieving a more stable combination between the steel beam and the concrete bridge deck.

[0032] 2. The stiffening base plate of the shear connector is equipped with bent stiffening side plates on all sides, and telescopic connecting rods are set between the stiffening side plates. This, combined with the inverted frustum design of the cylinder with a large upper opening and a small lower opening, achieves a tight and firm contact between the stiffening side plates and the cylinder side plates while the stiffening base plate is fixedly connected by high-strength bolts. This avoids the welding connection between the cylinder side plates and the stiffening base plate, making the processing and manufacturing of the shear connector more efficient and its shear and pull-out resistance superior to traditional shear connectors.

[0033] Third, shear connections using high-strength bolts exhibit significant advantages over welded connections in terms of disassembly, adjustability, ease of installation, and fault tolerance. High-strength bolt connections are disassembly-friendly, allowing for easy disassembly and reassembly of shear connections, which is crucial for maintenance, repair, and component replacement. Secondly, high-strength bolt connections are adjustable; by adjusting the tightening force of the high-strength bolts, the tightness and preload of the connection can be precisely controlled to meet specific engineering requirements. Furthermore, the installation process of bolted connections is relatively simple, requiring only appropriate tools for tightening, eliminating the need for specialized equipment and complex procedures required for welding, thereby reducing installation costs and time.

[0034] IV. Prefabricated UHPC panels exhibit significant advantages in strength, durability, lightweight design, and construction efficiency. UHPC panels possess exceptional strength and durability; their high strength allows them to withstand greater loads and provide long-term stable performance. Secondly, due to the high strength of UHPC, prefabricated UHPC panels can be designed with lightweight, thin layers, reducing weight and simplifying construction and installation. Furthermore, prefabrication and rapid installation improve construction efficiency, and panels can be customized to meet specific design requirements.

[0035] V. The combination of channel steel beams and stiffening ribs in their bottom and web plates constitutes a structural system with high strength, good rigidity, and strong adaptability. Its high strength and rigidity enable it to withstand large loads and resist deformation, while its light weight saves materials, reducing the structural self-weight and construction load. Channel steel beams offer flexibility and adaptability, allowing for customization according to project requirements and providing design flexibility. The stiffening ribs in the bottom and web plates further enhance the stiffness and stability of the channel steel beams, share the load, improve the overall structural bearing capacity and stability, and enhance bending and shear resistance.

[0036] VI. The synergistic cooperation between the channel steel beams and the precast bridge deck achieves optimized load-bearing capacity, fully leveraging the advantages of each. The channel steel beams possess high strength and rigidity, effectively bearing large loads and reducing deflection; simultaneously, the precast bridge deck, through its lightweight design and excellent material properties, reduces the overall structural weight, thereby lowering costs and foundation requirements; furthermore, the prefabrication process makes construction faster and more efficient, and the durability and low maintenance of UHPC materials reduce subsequent maintenance work and costs. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a structural schematic diagram of the steel-concrete composite beam containing shear connectors according to the present invention;

[0039] Figure 2 This is a schematic diagram of the structure of the channel steel beam of the present invention;

[0040] Figure 3 This is a schematic diagram of the shear connector of the present invention;

[0041] Figure 4 This is a schematic diagram of the assembly of the top cover plate of the shear connector of the present invention;

[0042] Figure 5 This is a schematic diagram of the component assembly of the shear connector of the present invention;

[0043] Figure 6 This is a schematic diagram of the assembly structure of the stiffening member of the shear connector of the present invention;

[0044] Figure 7 This is a schematic diagram of the assembly structure of the telescopic connecting rod of the present invention;

[0045] Figure 8 This is a schematic diagram showing the arrangement of the shear connector of the present invention on the channel steel beam;

[0046] Figure 9 This is a schematic diagram of the connection between the shear connector and the upper flange steel plate of the present invention.

[0047] In the diagram: 1. Precast bridge deck; 2. Shear connector; 3. Channel steel beam; 4. Upper flange steel plate; 5. Web steel plate; 6. Bottom steel plate; 7. Cylinder; 8. Through reinforcement; 9. First connecting hole; 10. Screw; 11. Nut; 12. Washer; 13. Stiffening bottom plate; 14. Stiffening side plate; 15. Second connecting hole; 16. Cast-in-place channel; 17. Web stiffening rib; 18. Bottom plate stiffening rib; 19. Bridge deck joint; 20. Third connecting hole; 21. High-strength bolt; 22. Groove; 23. Cover plate; 24. Telescopic connecting rod; 25. Sleeve; 26. Hinge device; 27. Connecting screw; 28. Fixing sleeve; 29. ​​Folding lifting ring; 30. Welded fixing plate; 31. Lifting ring; 32. Stop block; 33. Spherical head; 34. Smooth section; 35. Threaded section. Detailed Implementation

[0048] The present invention will be further described below with reference to specific preferred embodiments, but this does not limit the scope of protection of the present invention.

[0049] For ease of description, the relative positions of the components, such as top, bottom, left, right, etc., are described according to the layout direction of the accompanying drawings and do not limit the structure of this patent.

[0050] Please see Figure 1 An embodiment of the steel-concrete composite beam with shear connectors of the present invention includes a precast bridge deck 1, a shear connector 2, and a channel steel beam 3.

[0051] The precast bridge deck 1 is preferably a UHPC panel. The precast bridge deck 1 is a segmented precast bridge deck that is prefabricated in a factory. That is, the precast bridge deck is divided into multiple smaller block units for prefabrication, and then transported to the site for splicing and installation. The symmetry and balance of the segments need to be fully considered according to the specific bridge structure to ensure the overall balance and stability.

[0052] like Figure 2 As shown, the channel steel beam 3 includes an upper flange steel plate 4, a web steel plate 5, and a bottom steel plate 6. The bottom steel plate 6 is provided with bottom plate stiffening ribs 18, and the web steel plate 5 has web plate stiffening ribs 17 on its inner side. All components of the channel steel beam 3 are rigidly connected by welding. Third connecting holes 20 are symmetrically arranged on both sides of the upper flange steel plate 4 along the longitudinal central axis of the channel steel beam 3.

[0053] The precast bridge deck 1 is provided on the top surface of the upper flange steel plate 4. The precast bridge deck 1 has a slot 22 reserved at the corresponding position of the shear connector 2. The side length of the slot 22 is 15cm to 20cm. A cast-in-place groove 16 is formed between the slot 22 and the upper flange steel plate 4. The cast-in-place groove 16 is filled with a high-strength non-shrink grout.

[0054] like Figure 3 - Figure 6As shown, the shear connector 2 includes an inverted frustum-shaped cylinder 7, a stiffener placed inside the cylinder 7, a cover plate 23 covering the top of the cylinder 7, a through steel bar 8 that runs transversely through the cylinder 7, and a high-strength bolt 21 installed on the stiffener. The steel plates used for the cylinder 7, top cover plate 23, and stiffening base plate 13 are 3-7mm thick. The cylinder 7 is formed by bending steel plates into a square closed ring, with the joints connected by welding. The upper opening is 120mm×120mm or 150mm×150mm, and the lower opening is 60mm×60mm or 90mm×90mm. The overall height of the cylinder 7 is 80mm-100mm. The cylinder 7 has four side wall steel plates, and two opposite side wall steel plates are provided with transverse through holes 9 of the same height and size. The diameter of the through holes 9 is 20mm-30mm. The top of the inner wall of each of the four side plates of the cylinder 7 is provided with a stop block 32, which is 3mm×3mm×15mm in size and is located 7mm from the top of the vertical axis of the side wall steel plate.

[0055] The inverted frustum-shaped cylinder 7 is a cold-formed component. In this embodiment, it is made by bending a steel plate into a square closed ring, and the joints are connected by welding to form a cylinder with a large upper opening and a small lower opening. The cylinder 7 has four side wall steel plates, and two opposite side wall steel plates are provided with first connecting holes 9 that are transversely penetrating the cylinder 7 with the same height and size. The top of the inner wall of each of the four side plates of the cylinder 7 is provided with a stop block 32 to support the top cover plate 23 and prevent the cover plate 23 from tipping over.

[0056] The stiffening component includes an integrally formed stiffening base plate 13 and a stiffening side plate 14. The size of the stiffening base plate 13 is the same as the size of the lower opening of the cylinder 7 and fits the lower opening of the cylinder 7. The stiffening base plate 13 is provided with a second connecting hole 15 for high-strength bolts 21 to connect. The stiffening side plate 14 is arranged around the stiffening base plate 13 and fits the inner wall of the cylinder 7. The height of the stiffening side plate 14 is lower than the setting height of the first connecting hole 9.

[0057] In this embodiment, the stiffening base plate 13 is a square steel plate with dimensions consistent with the lower opening size of the cylinder 7; the stiffening side plates 14 are multiple pieces, evenly distributed around the stiffening base plate 13, and the stiffening side plates 14 are bent upward relative to the stiffening base plate 13. The bending angle of the stiffening side plates 14 is slightly larger than the inclination angle of the side wall steel plates on the cylinder 7 during processing; the height of the stiffening side plates 14 is half the height of the side wall steel plates of the cylinder 7, and a telescopic connecting rod 24 is welded between two opposing stiffening side plates 14 to adjust the fit between the stiffening side plates 14 and the side wall steel plates of the cylinder 7.

[0058] like Figure 4As shown, in this embodiment, the top cover plate 23 of the cylinder 7 is a square steel plate, slightly smaller than the upper opening size of the cylinder 7. A folding lifting ring 29 is provided in the center of its top surface to facilitate the installation and removal of the top cover plate. The folding lifting ring 29 includes a welded fixing plate 30 and a lifting ring 31. The welded fixing plate 30 is 3mm thick, and the lifting ring 29 is made of a 5mm diameter steel bar bent into shape. After the shear connector 2 is installed, the lifting ring 31 is folded to fit the top cover plate 23 to avoid affecting the paving construction of the precast bridge deck 1.

[0059] like Figure 5 , Figure 6 and Figure 7 As shown, the telescopic connecting rod 24 includes a connecting screw 27, a sleeve 25, a hinge device 26, and a fixing sleeve 28. The hinge device 26 is mounted on a stiffening side plate 14, and the fixing sleeve 28 is mounted on the opposite stiffening side plate 14. The sleeve 25 and the connecting screw 27 are telescopically connected by a threaded engagement. The connecting screw 27 consists of a spherical head 33, a smooth section 34, and a threaded section 35. The spherical head 33 has a diameter of 8mm, the screw section has a diameter of 5mm, and the rod length is 30mm. The smooth section 34 has a length of 8mm, and the threaded section 35 has a length of 22mm. A spherical cavity is provided inside the fixing sleeve 28, and the spherical head 33 is fitted inside the spherical cavity to form a "universal spherical rotary joint" structure, which allows the connecting screw 27 to rotate and change angles. The principle is to utilize the universal rotation of the universal spherical rotary joint and the fixing effect of the fixing sleeve, so that it can rotate and connect freely at different angles. The telescopic connecting rod 24 is telescopic, thereby adjusting the inclination angle of the stiffening side plate 14 connected to it. The smooth section 34 has a through hole for inserting tools to rotate the connecting screw 27. When rotating the connecting screw 27, steel wire is pre-wound through the through hole of the smooth section 34 to increase friction, and then the screw is rotated using needle-nose pliers. The sleeve 25 has a wall thickness of 2mm, a length of 30mm, and an inner diameter of 5mm, and its inner wall is threaded. The end of the sleeve 25 is equipped with a hinge device 26 fixedly connected to the stiffening side plate 13, which can accommodate the angle change of the telescopic connecting rod 24 during length changes. The hinge device 26 and the fixed sleeve 28 are welded to the stiffening side plate 14. The two mutually perpendicular telescopic connecting rods 24 are set at different heights; one is set at 1 / 2 the height of the stiffening side plate 14, and the other at 3 / 4 the height, so that each can be adjusted independently.

[0060] During installation, the stiffening base plate 13 is pre-tightened by the telescopic connecting rod 24 to reduce the inclination angle of the stiffening side plate 14, allowing it to be smoothly positioned inside the cylinder 7. Subsequently, the telescopic connecting rod 24 is loosened. Under the combined structural resistance of the elastic deformation of the stiffening side plate 14 and the support of the telescopic connecting rod 24, the stiffening side plate 14 and the side wall steel plate of the cylinder 7 are tightly fitted together. This allows the stiffening base plate 13 to be fixed to the channel steel beam 3 by high-strength bolts 21, while restricting the displacement of the cylinder 7 in both the horizontal and vertical directions.

[0061] The through-bar 8 is a ribbed steel bar that passes horizontally through the interior of the cylinder 7 through the first connecting hole 9 provided on the cylinder 7. The diameter of the through-bar 8 can be 10mm to 15mm.

[0062] The high-strength bolt 21 includes a bolt 10, a washer 12, and a nut 11. The bolt 10 consists of a hexagonal head, a smooth bolt section, and a threaded bolt section from top to bottom. The length of each bolt section is determined by the thickness of the stiffening base plate 13 of the connector and the thickness of the upper flange steel plate 4 of the channel steel beam 3, matching the actual engineering conditions. The diameter of the bolt 10 can be 12mm or 16mm. The design of the smooth bolt section avoids the threads on the bolt 10 from embedding inside the upper flange steel plate 4, thereby reducing the connection effect at the joint. The washer 12 is a steel washer with a thickness of 3mm to 5mm, and the diameter of the central opening matches the diameter of the bolt 10. The nut 11 is a hexagonal nut, and its specifications match the diameter of the bolt 10.

[0063] like Figure 8 , Figure 9 As shown, the diameter of the third connecting hole 20 provided on the upper flange steel plate 4 matches the diameter of the screw 10; the shear connector 2 is provided on the upper flange steel plate 4 along the longitudinal central axis of the channel steel beam 3, the through steel bar 8 of the shear connector 2 is parallel to the transverse direction of the channel steel beam 3, and is fixedly connected to the upper flange steel plate 4 by passing through the third connecting hole 20 with a high-strength bolt 21.

[0064] The construction process steps of the composite beam in this embodiment of the invention are as follows:

[0065] S1: The upper flange steel plate 4, the web steel plate 5, the bottom steel plate 6, the bottom plate stiffening rib 18, and the web plate stiffening rib 17 are connected by welding to form a channel steel beam 3.

[0066] S2: Prefabricate UHPC panels in sections (preferably prefabricated bridge deck panels 1), and reserve slots 22 on the UHPC panels; set a third connecting hole 20 on the upper flange steel plate 4 along the longitudinal center axis of the channel steel beam 3, and then hoist the UHPC panels onto the top surface of the upper flange steel plate 4, and align the slots 22 on the UHPC panels with the third connecting holes 20 on the upper flange steel plate 4.

[0067] S3: Place the cylinder 7 with the stiffened base plate 13 on the upper flange steel plate 4. The high-strength bolts 21 on the stiffened base plate 13 of the shear connector 2 correspond to the flange plate connection holes 20 of the upper flange steel plate 4 of the steel beam. Then, fix the shear connector 2 on the upper flange steel plate 4 by the cooperation of the nut 11 and the high-strength bolts 21. At the same time, the through steel bar 8 is configured and the top cover plate 23 is installed. After the shear connector 2 is installed, connect the through steel bar 8 to the structural steel bar of the precast UHPC slab through the steel bar sleeve.

[0068] S4: Construction of the bridge deck joints 19 between the precast UHPC panels involves preparation, joint material installation, filling, and leveling. During construction, first ensure the surface of the bridge deck joint 19 is flat and clean. Then, install and fix the polymer joint strip as required. Next, fill the bridge deck joint 19 with polymer concrete filler material, and after the filler dries, perform leveling to ensure the bridge deck joint 19 is flat and harmonious with the surrounding precast UHPC panels.

[0069] S5: High-strength, non-shrink grout is poured into the cast-in-place trough 16 to complete the assembly of the composite beam.

[0070] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can make many possible variations and modifications to the technical solution of the present invention, or modify it into equivalent embodiments with equivalent changes, without departing from the scope of the technical solution of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention should fall within the scope of protection of the technical solution of the present invention.

Claims

1. A shear connector, characterized in that: Includes a frustum-shaped cylinder (7), a stiffener placed inside the cylinder, a cover plate covering the top of the cylinder, a through steel bar (8) that runs horizontally through the cylinder, and a high-strength bolt (21) installed on the stiffener. The upper opening of the cylinder is large and the lower opening is small. A first connecting hole (9) is horizontally provided through the upper part of the cylinder. The stiffening component includes a stiffening base plate (13) and a stiffening side plate (14). The stiffening base plate and the stiffening side plate are integrally formed. The size of the stiffening base plate is consistent with the size of the lower opening of the cylinder and fits the lower opening of the cylinder. There are multiple stiffening side plates, and each stiffening side plate surrounds the stiffening base plate. The stiffening side plates installed opposite each other are connected by a telescopic connecting rod (24). Under the combined resistance of the elastic deformation of the stiffening side plate and the support of the telescopic connecting rod, the stiffening side plate fits tightly against the inner wall of the cylinder. The height of the stiffening side plate is lower than the first connecting hole. The cover plate covers the upper opening of the cylinder; The through-bar passes laterally through the first connecting hole through the cylinder, and connection sections for connecting with the bridge deck reinforcement are left on both sides of the cylinder. A second connecting hole is provided on the stiffening base plate, and the high-strength bolt is connected to the stiffening base plate through the second connecting hole.

2. The shear connector according to claim 1, characterized in that: The telescopic connecting rod includes a sleeve (25) and a connecting screw (27). One end of the sleeve is connected to one end of the connecting screw by a threaded connection. The other end of the sleeve is hinged to the stiffening side plate. The other end of the connecting screw is set as a spherical head (33). A fixed sleeve (28) with a spherical cavity is installed on the stiffening side plate. The spherical head of the connecting screw is connected to the spherical cavity of the fixed sleeve to form a spherical rotary joint.

3. The shear connector according to claim 1, characterized in that: The cylinder is a frustum shape.

4. The shear connector according to claim 1, characterized in that: The top of the inner wall of the cylinder is provided with a stop (32) for supporting the cover plate.

5. The shear connector according to claim 1, characterized in that: The top surface of the cover plate is provided with a lifting ring (31).

6. A steel-concrete composite beam with shear connectors, comprising a channel steel beam, shear connectors, and precast bridge deck, wherein the channel steel beam comprises an upper flange steel plate (4), a web steel plate (5), and a bottom steel plate (6), wherein the web steel plate is respectively disposed on both sides of the bottom steel plate, one end of the web steel plate is connected to the bottom steel plate, and the other end is connected to the upper flange steel plate, characterized in that: The shear connector is the shear connector according to any one of claims 1-5; A third connecting hole (20) is provided on the upper flange steel plate on both sides of the bottom steel plate. A slot (22) corresponding to the connecting hole on the upper flange steel plate is reserved on the precast bridge panel. The top surface of the upper flange steel plate is in contact with the bottom surface of the precast bridge panel. A cast-in-place groove is formed between the inner wall of the slot and the top surface of the upper flange steel plate. The shear connector is placed in the cast-in-place trough, and the two ends of the through steel bar are respectively connected to the structural steel bars of the precast bridge deck. The stiffening bottom plate and the upper flange steel plate are fixedly connected by the high-strength bolts passing through the third connecting hole. The cast-in-place concrete is poured in the cast-in-place trough.

7. The steel-concrete composite beam with shear connectors according to claim 6, characterized in that, The upper flange steel plates on both sides of the bottom steel plate are symmetrically provided with third connecting holes (20).

8. The steel-concrete composite beam with shear connectors according to claim 6, characterized in that, The through-bar reinforcement is arranged horizontally parallel to the channel steel beam.

9. A construction method for a steel-concrete composite beam according to any one of claims 6-8, characterized in that: First, the prefabricated bridge deck is hoisted onto the top surface of the upper flange steel plate of the channel steel beam, and the reserved slots on the prefabricated bridge deck are aligned with the reserved connection holes on the upper flange steel plate. Then, the cylinder with the stiffened bottom plate is placed on the upper flange steel plate. The second connection hole reserved on the stiffened bottom plate corresponds to the third connection hole on the upper flange steel plate. Then, the shear connector is fixed to the upper flange steel plate with high-strength bolts at the second connection hole and the third connection hole. At the same time, through steel bars are configured and the top cover plate is installed. After the shear connector is installed, the through steel bar and the structural steel bar of the precast bridge deck are connected by steel bar sleeve. Then, concrete filling material is poured into the cast-in-place trench, and construction is carried out at the joint of adjacent precast bridge decks. The construction is then completed.

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