Large-span prestressed steel-concrete composite structure and construction method thereof

Abstract

The application discloses a large-span prestressed steel-concrete composite structure and a construction method thereof, wherein the frame column and the beam of the large-span structure are all made of a steel-concrete composite structure, the frame column is a cross-shaped steel reinforced concrete column, the frame edge beam around the frame column is a box-shaped steel reinforced concrete beam, the middle large-span structure beam is a large-span variable cross-section prestressed steel-concrete composite structure beam, and the construction is performed by using a bonded post-tensioning prestressing technology; the tensioning end and the anchoring end are both embedded, the steel structure is deepened by opening, the tensioning end of the core area of the beam-column joint is added with a haunch, the steel bar positioning and passing rate design, the prestressed reverse bending point design and fixing are performed, and the quality and safety of the prestressed steel-concrete composite structure can be ensured, the construction efficiency can be improved, and the invention cost can be reduced.

Description

Technical Field

[0001] This invention relates to the field of architectural invention technology, and more specifically, to a large-span prestressed steel-concrete composite structure and its construction method. Background Technology

[0002] To meet the space requirements of public buildings, large-span structures such as swimming pools are often designed without frame columns, resulting in large spans and localized "heavy loads." This not only places stricter requirements on structural selection and layout but also presents challenges such as strict limits on building height, high requirements for deflection and crack control, stringent waterproofing requirements, and significant construction difficulties.

[0003] As an important combination of the two traditional structural forms of reinforced concrete and steel, the steel-concrete composite structure has the advantages of greater load-bearing capacity, greater stiffness and better seismic performance than traditional reinforced concrete structures. Prestressed design can improve the tensile strength and load-bearing capacity of concrete under load, prevent or delay the occurrence of cracks and increase the stiffness of the structure, and optimize the cross-sectional dimensions to save material usage.

[0004] Therefore, steel-concrete composite structures and prestressed concrete structures are used in large-span structures such as swimming pools due to their unique advantages in structural stress. However, when the building structure has a large span and is subjected to large stress, and the seismic fortification intensity is high, the above two types of structures may fail to meet the requirements in terms of stress and deflection calculations.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a large-span prestressed steel-concrete composite structure and its construction method, which can not only ensure the quality and safety of the prestressed steel-concrete composite structure, but also improve construction efficiency and reduce invention costs.

[0007] To solve the above-mentioned technical problems, the basic concept of the technical solution adopted by the present invention is as follows:

[0008] Firstly, a large-span prestressed steel-concrete composite structure includes:

[0009] The composite beam is composed of a concrete beam and an I-beam, and both ends of the concrete beam and the I-beam are integrally cast with the frame column.

[0010] The prestressed corrugated pipe is integrally cast with the concrete beam, and one end of the prestressed corrugated pipe is a fixed end and the other end is a tensioning end.

[0011] The concrete beam includes upper main reinforcement, lower main reinforcement, first anti-torsion reinforcement, additional side reinforcement and main reinforcement tied together, and the upper main reinforcement, lower main reinforcement, first anti-torsion reinforcement, additional side reinforcement and main reinforcement are integrally cast with concrete.

[0012] In a preferred embodiment of any of the above schemes, the tensioning end of the prestressed frame beam is arranged outside the core area of ​​the beam and column by using a horizontal haunch method on the side of the beam; the tensioning end of the prestressed secondary beam is arranged outside the supporting beam by using an exposed anchorage method; the horizontal haunch is equipped with top additional reinforcement, bottom additional reinforcement, web reinforcement additional reinforcement and stirrups to achieve local bearing pressure of the horizontal haunch;

[0013] Add connecting plates or sleeves at the stiffening plate positions inside the column to connect with the second and third rows of reinforcing bars; set stirrup connecting plates on the web of the box-type steel beam, and weld the stirrups to the stirrup connecting plates; when the bent reinforcing bars encounter the web of the box-type steel beam, open holes for straight bars to pass through, passing through the webs on both sides of the box beam and the web of the column.

[0014] In a preferred embodiment of any of the above schemes, the U-shaped prestressed tendon positioning bar fixes the corrugated pipe to the steel pipe, the U-shaped prestressed tendon positioning bar is welded to the web of the steel pipe on one side with a 10d weld, and the distance between adjacent prestressed tendon positioning bars is ≤1000mm.

[0015] In a preferred embodiment of any of the above schemes, the large-span prestressed steel-concrete composite structure further includes:

[0016] The second anti-torsion steel bar is tied to the first anti-torsion steel bar at both ends;

[0017] The vertical additional reinforcing bars are tied to the second anti-torsion reinforcing bars, and the beam side additional reinforcing bars are tied to the vertical additional reinforcing bars and the second anti-torsion reinforcing bars;

[0018] The vertical reinforcing bars are tied to the second anti-torsional reinforcing bars;

[0019] The vertical additional reinforcing bars are tied to the second anti-torsional reinforcing bars.

[0020] In a preferred embodiment of any of the above schemes, the large-span prestressed steel-concrete composite structure further includes:

[0021] The vent extends into the composite beam at one end and out of the composite beam at the other end;

[0022] A horizontal turning point is provided at the junction of the prestressed corrugated pipe and the frame column.

[0023] In a preferred embodiment of any of the above schemes, the large-span prestressed steel-concrete composite structure further includes:

[0024] The inflection point is set on the prestressed corrugated pipe;

[0025] Grouting holes are located in the middle of the composite beam.

[0026] In a preferred embodiment of any of the above schemes, the large-span prestressed steel-concrete composite structure further includes:

[0027] The steel mesh is connected to the tensioned end that extends to the outside of the frame column.

[0028] In a preferred embodiment of any of the above solutions, a prestressed tendon is provided inside the prestressed corrugated pipe, and the tensioning end includes:

[0029] Anchor plate, fitted onto the outside of the prestressed corrugated pipe;

[0030] Spiral reinforcement is wound around the outside of the anchor plate;

[0031] An anchor plate, connected to the anchor pad plate, and also connected to the prestressing tendon;

[0032] The sealing end is connected to the prestressed tendon and the anchor plate;

[0033] The reinforcing bars are fixed and connected to the anchor plate and prestressed tendons.

[0034] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art.

[0035] The large-span structural frame columns and beams all adopt steel-concrete composite structures. The frame columns are cross-shaped steel-concrete columns, the perimeter frame beams are box-shaped steel-concrete beams, and the large-span structural beams in the middle are large-span variable cross-section prestressed steel-concrete composite structural beams. The construction adopts bonded post-tensioning prestressing technology. The tensioning end and anchorage end are both embedded, and the anchorage is anchored into the concrete structure. After the prestressing tendons are tensioned, the anchor heads and anchor plates of the tensioning end and other metal components should be coated with special anti-corrosion grease or epoxy resin and the tensioning end should be sealed with micro-expansion fine stone concrete.

[0036] The composite beam is composed of concrete beams and I-beams, cast integrally with the frame columns at both ends. This structure provides high stiffness and strength. The concrete beams primarily resist compressive forces, while the I-beams primarily resist tensile forces; their combination leverages the advantages of each. The prestressed corrugated pipes are cast integrally with the concrete beams. These prestressed corrugated pipes are typically filled with prestressed steel bars. By tensioning these bars, prestress is generated, which helps improve the beam's load-bearing capacity and stiffness. The frame columns are cast integrally with the composite beams, providing support and bearing the loads transmitted from the beams.

[0037] Secondly, a construction method for a large-span prestressed steel-concrete composite structure, the method comprising the following steps:

[0038] The steel columns and steel beam frame columns are hoisted to the designated positions and welded to construct the building's frame columns;

[0039] On the foundation of the frame columns, a prestressed concrete beam support scaffold is erected, and the bottom formwork of the beam is erected to create an arch and the bottom elevation of the beam is calibrated to form a support structure.

[0040] On the supporting structure, a non-prestressed steel reinforcement skeleton is tied, while the prestressed material is transported to the designated location;

[0041] Using the prestressed materials that have been transported to the designated location, install and fix the prestressed positioning steel bars, install the prestressed corrugated pipes and insert the prestressed steel strands, and install and fix the prestressed tensioning end and anchorage end nodes to form a prestressed system.

[0042] After the prestressed system is installed, non-prestressed steel bars, professional pipelines, and prestressed concrete beam formwork are installed.

[0043] After the installation of all prestressed and non-prestressed systems is completed, a concealed inspection is carried out, and concrete is poured. Once the concrete reaches the tension design strength, the beam end formwork is removed.

[0044] After the concrete strength meets the requirements, prestressing is carried out, the ducts are grouted, excess exposed steel strands are cut off, and the tensioning end nodes are concealed and sealed.

[0045] In a preferred embodiment of any of the above schemes, the steel columns and steel beam frame columns are hoisted to the designated positions and welded to construct the building's frame columns, including:

[0046] Based on the architectural design drawings, calculate and determine the dimensions, quantity, and location of the steel columns and beams;

[0047] The steel is cut and shaped to produce steel columns and beams that meet the design requirements, and the manufactured steel columns and beams are transported to the construction site.

[0048] Use a crane to lift the steel columns and beams to the positions specified in the design;

[0049] Welding equipment is used to weld steel columns and beams together to construct the building's frame columns.

[0050] In a preferred embodiment of any of the above schemes, a prestressed concrete beam support scaffold is erected on the foundation of the frame columns, and the bottom formwork of the beam is simultaneously erected, cambered, and the bottom elevation of the beam is calibrated to form a support structure, including:

[0051] According to the design drawings and construction requirements, erect the prestressed concrete beam support scaffolding;

[0052] Install the bottom formwork of the beam on the scaffolding, and carry out the cambering operation of the bottom formwork of the beam according to the design and site conditions;

[0053] Use measuring equipment to calibrate the elevation of the bottom formwork of the beam.

[0054] In a preferred embodiment of any of the above solutions, a non-prestressed steel reinforcement cage is tied to the supporting structure, while the prestressed material is transported to a designated location, including:

[0055] According to the design drawings and construction specifications, the non-prestressed steel bars are tied in the prescribed manner and sequence to form a skeleton;

[0056] After the non-prestressed steel reinforcement cage is tied, the prestressed steel bars or strands, anchors, and corrugated pipes are transported to the construction site according to the positions and quantities required by the drawings.

[0057] In a preferred embodiment of any of the above schemes, the prestressed material already transported to the designated location is used to install and fix the prestressed positioning steel bars, install the prestressed corrugated pipes and insert the prestressed steel strands, and install and fix the prestressed tensioning end and anchorage end nodes to form a prestressed system, including:

[0058] According to the design drawings, the prestressed positioning steel bars are installed in the designated positions and fixed with steel bar binding.

[0059] After the positioning steel bars are fixed, install the prestressed corrugated pipes according to the design requirements;

[0060] After the corrugated pipe is installed, the prestressed steel strands are threaded into the corrugated pipe. After the steel strands are threaded into the corrugated pipe, the prestressed tensioning end and anchoring end nodes are installed and fixed. According to the tensioning sequence, one end of the steel strand is anchored and the other end is tensioned.

[0061] In a preferred embodiment of any of the above solutions, after the prestressed system is installed, the installation of non-prestressed steel bars, professional pipelines, and prestressed concrete beam formwork includes:

[0062] According to the design drawings, install the steel bars in the designated positions and tie them with steel bars;

[0063] After the steel reinforcement is installed, install the specialized pipelines;

[0064] After the steel reinforcement and pipelines are installed, install the side and top formwork of the concrete beam.

[0065] In a preferred embodiment of any of the above schemes, after the installation of all prestressed and non-prestressed systems is completed, a concealed acceptance inspection is conducted, and concrete is poured. Once the concrete reaches the tension design strength, the beam end formwork is removed, including:

[0066] After the prestressed system and non-prestressed system are installed, a concealed acceptance inspection is carried out.

[0067] After the inspection is passed, the concrete will be poured.

[0068] Once the concrete reaches its designed tension strength, the beam end formwork is removed.

[0069] In a preferred embodiment of any of the above schemes, after the concrete strength meets the requirements, prestressing is performed, followed by grouting of the ducts, removal of excess exposed steel strands, and concealed sealing of the tensioning end nodes, including:

[0070] Tensioning equipment is used to tension prestressed steel bars or steel strands;

[0071] After tensioning is completed, the cavity inside the corrugated pipe is grouted.

[0072] After the grouting is completed and the strength meets the requirements, the excess steel strands exposed on the concrete surface are cut off.

[0073] The nodes at the tensioning end are concealed and sealed.

[0074] In a preferred embodiment of any of the above solutions, tensioning the prestressed steel bars or steel strands using a tensioning device includes:

[0075] Inspect the tensioning equipment to ensure it is in good working order;

[0076] The tensioning equipment is attached to one end of the prestressed steel bar or steel strand;

[0077] Start the equipment to tension the prestressed steel bars or steel strands.

[0078] In a preferred embodiment of any of the above solutions, tensioning the reinforcing bars or steel strands includes:

[0079] Using force and displacement indicators, the tension force and elongation of prestressed steel bars or strands can be monitored in real time.

[0080] The monitored data is recorded and compared with the design requirements. If the actual tension or elongation does not meet the design requirements, tensioning is stopped. If the actual tension or elongation exceeds the design requirements, the tension is reduced by adjusting the equipment until the design requirements are met.

[0081] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art.

[0082] By employing precise prefabrication and on-site construction, the correct installation and stress control of the prestressed system are ensured, effectively improving the strength and stability of the structure. Furthermore, this invention takes into account aspects such as concrete pouring and curing, thereby guaranteeing the quality and strength of the concrete and improving the durability of the structure. In addition, this invention simplifies the construction process, improves construction efficiency, and reduces invention costs.

[0083] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0084] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. Some specific embodiments of this application will be described in detail below with reference to the accompanying drawings in an exemplary and non-limiting manner. The same reference numerals in the drawings designate the same or similar parts or components. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the drawings:

[0085] Figure 1 This is a schematic diagram of the prestressed internal structure of the construction method for large-span prestressed steel-concrete composite structures of the present invention.

[0086] Figure 2 This is a schematic diagram of the prestressed tendon positioning in the construction method of the large-span prestressed steel-concrete composite structure of the present invention.

[0087] Figure 3 This is a schematic diagram of the grouting hole setting in the construction method of the large-span prestressed steel-concrete composite structure of the present invention.

[0088] Figure 4 This is a schematic diagram of the prestressed secondary beam tensioning end in the construction method of the large-span prestressed steel-concrete composite structure of the present invention.

[0089] Figure 5 This invention relates to a construction method for large-span prestressed steel-concrete composite structures. Figure 4 A schematic diagram of the AA cross section.

[0090] Figure 6 This is a plan view of the beam-column joint with haunches in the large-span prestressed steel-concrete composite structure of the present invention.

[0091] In the attached diagram: 1. Composite beam; 2. I-beam; 3. Prestressed corrugated pipe; 4. Frame column; 5. Tensioning end; 6. Fixed end; 7. Vent hole; 8. Inflection point; 9. Grouting hole; 10. Steel mesh; 11. Horizontal section turning point; 12. Top main reinforcement; 13. Torsional reinforcement; 14. Additional reinforcement on beam side; 15. Main reinforcement; 16. Vertical additional reinforcement; 17. Vertical additional reinforcement; 18. Bottom main reinforcement; 19. Torsional reinforcement; 20. Vertical reinforcing reinforcement; 21. Spiral reinforcement; 22. Fixed reinforcement; 23. Prestressed tendon; 24. Anchor plate; 25. Sealed anchor end; 26. Anchor plate.

[0092] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0093] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative effort should fall within the scope of protection of the present application.

[0094] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0095] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0096] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0097] The following embodiments of this application use the construction method of a large-span prestressed steel-concrete composite structure as an example to illustrate the solution of this application. However, these embodiments do not limit the scope of protection of this application.

[0098] like Figures 1 to 5 As shown, a large-span prestressed steel-concrete composite structure includes:

[0099] Composite beam 1 is composed of a concrete beam and an I-beam 2, and both ends of the concrete beam and the I-beam 2 are integrally cast with the frame column 4.

[0100] The prestressed corrugated pipe 3 is integrally cast with the concrete beam, and one end of the prestressed corrugated pipe 3 is a fixed end 6, and the other end is a tensioning end 5.

[0101] The concrete beam includes upper main reinforcement 12, lower main reinforcement 18, first anti-torsion reinforcement 13, beam side additional reinforcement 14 and main reinforcement 15 tied together, and the upper main reinforcement 12, lower main reinforcement 18, first anti-torsion reinforcement 13, beam side additional reinforcement 14 and main reinforcement 15 are integrally cast with concrete.

[0102] In this embodiment of the invention, the large-span structural frame columns and beams all adopt steel-concrete composite structures. The frame columns are cross-shaped steel-concrete columns, the perimeter frame beams are box-shaped steel-concrete beams, and the central large-span structural beams are large-span variable cross-section prestressed steel-concrete composite structural beams. The construction adopts bonded post-tensioning prestressing technology. Both the tensioning end and the anchoring end are embedded, and the anchorage is anchored into the concrete structure. After the prestressing tendons are tensioned, the tensioning end anchor head and anchor plate and other metal components should be brushed with special anti-corrosion grease or epoxy resin and the tensioning end should be sealed with micro-expansion fine stone concrete.

[0103] In this embodiment of the invention, the composite beam 1 is composed of a concrete beam and an I-beam 2, integrally cast at both ends with the frame columns 4. This structure provides high stiffness and strength. The concrete beam primarily resists compressive forces, while the I-beam primarily resists tensile forces; their combined use leverages their respective advantages. The prestressed corrugated pipe 3 is integrally cast with the concrete beam. The prestressed corrugated pipe is typically filled with prestressed steel bars. Tensioning these steel bars generates prestress, which helps improve the beam's load-bearing capacity and stiffness. The frame columns 4 are integrally cast with the composite beam, providing support for the beam and bearing the loads transmitted from it.

[0104] In this embodiment of the invention, the upper main reinforcement 12, lower main reinforcement 18, first anti-torsional reinforcement 13, beam-side additional reinforcement 14, and main reinforcement 15 primarily bear the tensile and compressive stresses generated by bending moment. The first anti-torsional reinforcement resists torque, while the beam-side additional reinforcement and main reinforcement resist lateral shear force and provide stability to the web. This large-span prestressed steel-concrete composite structure, by rationally utilizing the advantages of various materials and components, provides high stiffness and load-bearing capacity, enabling its application in large-span bridges or building structures.

[0105] like Figures 1 to 5 As shown, the large-span prestressed steel-concrete composite structure further includes:

[0106] The second anti-torsion steel bar 19 is tied to the first anti-torsion steel bar 13 at both ends;

[0107] The vertical additional reinforcing bar 16 is tied to the second anti-torsion reinforcing bar 19, and the beam side additional reinforcing bar 14 is tied to the vertical additional reinforcing bar 16 and the second anti-torsion reinforcing bar 19.

[0108] The vertical reinforcing bar 20 is tied to the second anti-torsional reinforcing bar 19;

[0109] The vertical additional reinforcing bar 17 is tied to the second anti-torsion reinforcing bar 19.

[0110] In this embodiment of the invention, the second anti-torsional reinforcement 19 is tied to the first anti-torsional reinforcement 13 at both ends. Together, they resist torque caused by loads or other external forces, helping to maintain the stability of the structure. The vertical additional reinforcement 16 is tied to the second anti-torsional reinforcement 19, providing vertical support to resist shear and torque, enhancing the overall stability of the concrete beam. The beam-side additional reinforcement 14 is tied to the vertical additional reinforcement 16 and the second anti-torsional reinforcement 19, together enhancing the lateral stability of the beam and resisting shear stress. The vertical reinforcing reinforcement 20 is tied to the second anti-torsional reinforcement 19, providing additional vertical strength to help resist bending and torque of the beam. The vertical additional reinforcement 17 is tied to the second anti-torsional reinforcement 19, also providing vertical support and enhancing the stability of the beam. These reinforcements, tied together in the positions and manner determined by design requirements, collectively improve the stability of the entire structure, resisting various possible stresses, especially shear stress and torque.

[0111] like Figures 1 to 5 As shown, the large-span prestressed steel-concrete composite structure further includes:

[0112] The exhaust port 7 extends into the composite beam 1 at one end and out of the composite beam 1 at the other end;

[0113] A horizontal turning point 11 is provided at the junction of the prestressed corrugated pipe 3 and the frame column 4.

[0114] In this embodiment of the invention, one end of the vent 7 extends into the composite beam 1, and the other end extends out of the composite beam 1. The vent is mainly designed to remove air or other gases from inside the beam during concrete pouring, preventing the formation of air pockets or pores. This improves the density of the concrete, ensuring concrete quality and structural strength. The horizontal section turning point 11 is located at the junction of the prestressed corrugated pipe 3 and the frame column 4. This design ensures the stability of the prestressed steel bars when entering or leaving the prestressed pipe, avoiding uneven tension or wear caused by turning, and guaranteeing the tensioning quality of the prestressed steel bars. This large-span prestressed steel-concrete composite structure exhibits greater stability and durability, and can withstand complex loads and environmental conditions.

[0115] like Figures 1 to 5 As shown, the large-span prestressed steel-concrete composite structure further includes:

[0116] The inflection point 8 is located on the prestressed corrugated pipe 3;

[0117] Grouting hole 9 is located in the middle of the composite beam 1.

[0118] In this embodiment of the invention, the inflection point 8, located on the prestressed corrugated pipe 3, is used to change the orientation of the prestressed steel bars, better distribute the prestress, and increase the elasticity of the structure. This can improve the seismic performance of the structure to a certain extent. The grouting hole 9 is located in the middle of the composite beam 1. The main function of the grouting hole is to fill the inside of the corrugated pipe with cement grout after the prestressed steel bars are tensioned, so as to protect the prestressed steel bars and prevent their corrosion, while also enhancing the stiffness and load-bearing capacity of the structure. This invention makes the use of prestressed steel bars safer and more effective, while also improving the robustness and durability of the entire structure.

[0119] like Figures 1 to 5 As shown, the large-span prestressed steel-concrete composite structure further includes:

[0120] The reinforcing mesh 10 is connected to the tensioning end 5 extending to the outside of the frame column 4; the prestressed corrugated pipe 3 is provided with prestressed tendons 23, and the tensioning end 5 includes:

[0121] Anchor plate 26 is sleeved on the outside of the prestressed corrugated pipe 3;

[0122] Spiral reinforcement 21 is wound around the outside of the anchor plate 26;

[0123] Anchor plate 24 is connected to anchor pad plate 26 and prestressing tendon 23;

[0124] The sealing end 25 is connected to the prestressed tendon 23 and the anchor plate 24;

[0125] The fixed reinforcing bar 22 is connected to the anchor plate 26 and the prestressed tendon 23.

[0126] In this embodiment of the invention, the reinforcing mesh 10 provides additional tensile strength and crack control. During the concrete hardening process, the reinforcing mesh works alongside the concrete to prevent cracks caused by stress concentration, thus enhancing the overall stability and durability of the concrete. The anchor plate 26 distributes the load of the prestressing tendons over a larger concrete area, preventing concrete cracking due to excessive local stress. Simultaneously, the anchor plate protects the prestressing tendons from direct contact with the concrete and potential damage. The spiral reinforcement 21 provides additional longitudinal and transverse restraint, enhancing the shear strength and ductility of the concrete, especially under transverse loads such as earthquakes, effectively preventing or reducing shear failure. The anchor plate 24 fixes the prestressing tendons 23 in predetermined positions, transferring prestress to the concrete. By adjusting the shape and size of the anchor plate, a suitable prestress distribution can be obtained, thereby optimizing structural performance. The sealing anchor end 25 protects the ends of the prestressing tendons from oxidation and corrosion. Especially in harsh environments, the presence of the sealing anchor end effectively extends the service life of the prestressing tendons. The function of the fixing steel bar 22 is to fix the position of the prestressing tendon and the anchor plate, prevent displacement during tensioning, and ensure the correct tensioning of the prestressing tendon and the effective transfer of prestress.

[0127] like Figures 1 to 5 As shown, this invention provides a construction method for a large-span prestressed steel-concrete composite structure, the method comprising the following steps:

[0128] Step 11: Hoist the steel columns and steel beam frame columns to the designated positions and weld them to construct the building's frame columns;

[0129] Step 12: On the foundation of the frame columns, erect a prestressed concrete beam support scaffold, and at the same time erect the beam bottom formwork, camber it, and calibrate the beam bottom elevation to form a support structure;

[0130] Step 13: Tie the non-prestressed steel reinforcement cage onto the support structure, and at the same time transport the prestressed material to the designated location;

[0131] Step 14: Using the prestressed materials that have been transported to the designated location, install and fix the prestressed positioning steel bars, install the prestressed corrugated pipes and insert the prestressed steel strands, and install and fix the prestressed tensioning end and anchorage end nodes to form a prestressed system.

[0132] Step 15: After the prestressed system is installed, install the non-prestressed steel bars, professional pipelines, and prestressed concrete beam formwork;

[0133] Step 16: After the installation of all prestressed and non-prestressed systems is completed, conduct concealed acceptance and pour concrete. Once the concrete reaches the tension design strength, remove the beam end formwork.

[0134] Step 17: After the concrete strength meets the requirements, perform prestressing tensioning, grout the ducts, cut off excess exposed steel strands, and conceal and seal the tensioning end nodes.

[0135] In this embodiment of the invention, considering the dual characteristics of steel structure construction and prestressed construction, the design of the prestressed duct alignment needs to consider not only potential interference with ordinary reinforcing bars, but also potential interference with steel beams and columns. During the detailed design phase, interference analysis was performed using 3D-aided modeling with TeklaStructures software. All openings at potential interference locations were prefabricated before the steel structure left the factory, avoiding on-site drilling.

[0136] like Figure 6 As shown, to avoid weakening the beam-column core area or the cross-section of the supporting beam by the anchor head, the tensioning end of the prestressed frame beam in this invention adopts a horizontal haunch method on the beam side, placing the tensioning end outside the beam-column core area. The tensioning end of the prestressed secondary beam adopts an exposed anchorage method, placing the tensioning end outside the supporting beam. The horizontal haunch is equipped with top additional reinforcement, bottom additional reinforcement, web reinforcement, and stirrups to ensure the local bearing capacity of the horizontal haunch. During construction, the quality of concrete pouring and reinforcement binding must be strictly guaranteed.

[0137] In this embodiment of the invention, precise prefabrication and on-site construction ensure the correct installation and stress control of the prestressed system, effectively improving the strength and stability of the structure. Simultaneously, the invention also considers concrete pouring and curing, thereby guaranteeing the quality and strength of the concrete and improving the durability of the structure. Furthermore, this invention simplifies the construction process, improves construction efficiency, and reduces invention costs.

[0138] In a preferred embodiment of the present invention, step 11 above may include:

[0139] Step 111: Based on the architectural design drawings, calculate and determine the dimensions, quantity, and location of the steel columns and beams;

[0140] Step 112: Cut and shape the steel to produce steel columns and beams that meet the design requirements, and transport the manufactured steel columns and beams to the construction site.

[0141] Step 113: Use a crane to hoist the steel columns and beams to the positions specified in the design;

[0142] Step 114: Use welding equipment to weld the steel columns and steel beams together to construct the building's frame columns.

[0143] In this embodiment of the invention, to ensure the design requirements for the penetration rate of the main beam reinforcement, the main beam reinforcement is treated by merging the reinforcement according to relevant standards, while ensuring accuracy and penetration rate. After merging, the main beam reinforcement can pass through the core area of ​​the node better, thus better ensuring the penetration rate required by the design. Furthermore, the reinforcement penetration rate can be reduced to approximately 40%. Connecting plates or sleeves can be added at the stiffening plate positions within the column to connect with the second and third rows of reinforcement. Stirrup connecting plates are set in the web of the box-type steel beam, and the stirrups are welded to them. When bent reinforcement encounters the web of the box-type steel beam, perforated straight reinforcement passes through, penetrating both sides of the box-type beam web and the column web. Due to the large amount of welding and the significant fire hazard, the inner limb stirrups are changed to tie rods to reduce the amount of welding. These measures, combined with the requirements for prestressed applications, optimize the reinforcement connection method in the steel node area. According to the specifications and the linear curve equation of the prestressing tendon, the inflection point of the prestressing tendon is reasonably calculated, and the corrugated pipe and the steel pipe are fixed by designing U-shaped prestressing tendon positioning tendons. The positioning tendons are welded to the web of the steel section on one side by 10d. The distance between adjacent prestressing tendon positioning tendons is not greater than 1000mm, so as to ensure the accuracy of the prestressing curve and the positioning of the inflection point and improve the construction quality of the prestressed beam. The prestressing tendon curve equation is: y=he{1}-b(x-0.5L)[2]. When 0≤x≤0.40L, y=a×[2]+e[2], where a=5(h-e1-e2) / [2]; when 0.40≤x≤0.50L, y=he{1}-b(x-0.5L)[2], where b=20(he{1}-e{2}) / L[2].

[0144] In this embodiment of the invention, to achieve precise conversion of architectural design, the dimensions, quantity, and location of steel columns and beams are calculated and determined based on architectural design drawings. This provides accurate parameters for subsequent construction, avoids construction errors, and helps ensure building quality and construction progress. To manufacture steel columns and beams that meet design requirements, steel is cut and shaped to produce steel columns of various sizes and shapes to meet different building needs. Simultaneously, the manufactured steel columns and beams are transported to the construction site, providing necessary materials for subsequent construction and improving construction efficiency. To accurately install the steel columns and beams into the designated locations, cranes are used for hoisting, ensuring accurate and rapid installation and guaranteeing structural stability, which is beneficial for subsequent construction. To construct the building's frame columns, steel columns and beams are welded together using welding equipment, quickly constructing a solid and stable building frame column, laying a solid foundation for subsequent construction, and ensuring the building's stability and safety.

[0145] In a preferred embodiment of the present invention, step 12 above may include:

[0146] Step 121: Erect prestressed concrete beam support scaffolding according to the design drawings and construction requirements;

[0147] Step 122: Install the bottom formwork of the beam on the scaffolding, and perform the cambering operation of the bottom formwork of the beam according to the design and site conditions;

[0148] Step 123: Use measuring equipment to calibrate the elevation of the bottom formwork of the beam.

[0149] In this embodiment of the invention, to provide a stable and safe platform for subsequent construction operations, scaffolding supporting the prestressed concrete beams is erected according to the design drawings and construction requirements. This ensures worker safety during construction and provides necessary support for subsequent concrete pouring and other operations. To accurately install the beam bottom formwork and perform cambering operations according to design requirements, the beam bottom formwork is installed on the scaffolding. This ensures that the shape and dimensions of the concrete beam meet design requirements. Furthermore, cambering the beam bottom formwork according to design and site conditions effectively controls the bending moment and shear force of the prestressed concrete beam during construction, improving its structural performance. To confirm the accuracy of the beam bottom formwork's position, measuring equipment is used to calibrate its elevation. This ensures that the beam bottom formwork matches the height on the design drawings, thereby ensuring the accurate height and position of the prestressed concrete beam and contributing to the overall quality and stability of the building.

[0150] In a preferred embodiment of the present invention, step 13 above may include:

[0151] Step 131: According to the design drawings and construction specifications, tie the non-prestressed steel bars in the prescribed manner and sequence to form a skeleton;

[0152] Step 132: After the non-prestressed steel reinforcement cage is tied, transport the prestressed steel bars or steel strands, anchorages, and corrugated pipes to the construction site according to the positions and quantities required by the drawings.

[0153] In this embodiment of the invention, to construct the reinforcing steel skeleton of the concrete beam, non-prestressed steel bars are tied in a prescribed manner and sequence according to the design drawings and construction specifications to form the skeleton. This is a crucial step in ensuring that the concrete beam has sufficient load-bearing capacity and strength. The tying method and sequence of the non-prestressed steel bar skeleton directly affect the subsequent quality of the concrete beam; therefore, this step requires strict adherence to the design and specifications. To transport the main components of the prestressed system to the construction site and prepare for subsequent construction operations, prestressed steel bars or strands, anchorages, and corrugated pipes are essential materials for constructing prestressed concrete beams. Their quality and installation location directly affect the performance of the concrete beam. Therefore, transporting these materials to the construction site according to the locations and quantities specified in the drawings is a crucial step in ensuring construction quality.

[0154] In a preferred embodiment of the present invention, step 14 above may include:

[0155] Step 141: According to the requirements of the design drawings, install the prestressed positioning steel bars to the designated positions and fix them with steel bar ties;

[0156] Step 142: After the positioning steel bars are fixed, install the prestressed corrugated pipes according to the design requirements;

[0157] Step 143: After the corrugated pipe is installed, the prestressed steel strands are threaded into the corrugated pipe. After the steel strands are threaded into the corrugated pipe, the prestressed tensioning end and anchoring end nodes are installed and fixed. According to the tensioning sequence, one end of the steel strand is anchored and the other end is tensioned.

[0158] In this embodiment of the invention, to inflate prestress in a concrete beam, prestressing positioning steel bars are installed at designated positions according to the design drawings and secured with steel bar ties. This ensures that the direction and magnitude of the prestress meet design requirements, thereby improving the load-bearing capacity and durability of the concrete beam. To install the prestressed corrugated pipe, after the positioning steel bars are fixed, the prestressed corrugated pipe is installed according to design requirements. The corrugated pipe protects the steel bars or strands from direct contact with concrete, preventing corrosion and ensuring the safety and durability of the prestressing system. To thread the prestressed steel strands into the corrugated pipe and perform tensioning and anchoring, after the steel strands are threaded into the corrugated pipe, the prestressing tensioning end and anchoring end nodes are installed and fixed. According to the tensioning sequence, one end of the steel strand is anchored, and the other end is tensioned. This achieves prestressing within the concrete beam, improving its load-bearing capacity and effectively preventing cracking, thus enhancing the concrete beam's durability.

[0159] In a preferred embodiment of the present invention, step 15 may include:

[0160] Step 151: According to the requirements of the design drawings, install the steel bars to the designated positions and tie them with steel bars;

[0161] Step 152: After the steel reinforcement is installed, install the specialized pipelines;

[0162] Step 153: After the reinforcement and pipeline installation is completed, install the side formwork and top formwork of the concrete beam.

[0163] In this embodiment of the invention, to install non-prestressed steel bars in a concrete beam, the bars are installed in designated positions and tied according to the design drawings. This process is one of the fundamental procedures for constructing a concrete beam, and the position and tying method of the bars directly affect the stability and load-bearing capacity of the concrete beam. To install specialized pipelines in the concrete beam, after the steel bars are installed, these pipelines, such as electrical conduits and drainage pipes, are installed. These pipelines play important roles in the building, such as providing power supply and drainage; therefore, their installation position and method must strictly adhere to the design requirements. To construct the shape of the concrete beam, after the steel bars and pipelines are installed, the side and top formwork of the concrete beam are installed. The shape and size of these formworks will determine the final shape and size of the concrete beam; therefore, their installation position and method must strictly adhere to the design requirements. After this step is completed, concrete pouring can proceed.

[0164] In a preferred embodiment of the present invention, step 16 above may include:

[0165] Step 161: After the prestressed system and non-prestressed system are installed, conduct concealed acceptance.

[0166] Step 162: After the inspection is passed, concrete will be poured.

[0167] Step 163: Once the concrete has reached its designed tension strength, remove the beam end formwork.

[0168] In this embodiment of the invention, to confirm whether the installation of the prestressed and non-prestressed systems meets the design requirements and construction specifications, ensuring construction quality and safety, a concealed acceptance inspection is conducted after the systems are installed. This inspection checks whether various indicators meet standards, such as the quantity, location, and binding method of the reinforcing bars, and the installation status of the prestressed system. To construct the concrete beam structure, after acceptance, concrete is poured according to design requirements. During pouring, the pouring speed, thickness, and curing process need to be controlled to ensure the quality and stability of the concrete beam. For subsequent construction operations, once the concrete reaches its design tension strength, the beam end formwork is removed. Removing the beam end formwork allows for better curing of the concrete beam and facilitates subsequent construction operations, such as prestressing.

[0169] In a preferred embodiment of the present invention, step 17 above may include:

[0170] Step 171: Tension the prestressed steel bars or steel strands using tensioning equipment;

[0171] Step 172: After tensioning is completed, the cavity inside the corrugated pipe is grouted.

[0172] Step 173: After the grouting is completed and the strength meets the standard, the excess steel strands exposed on the concrete surface are cut off.

[0173] Step 174: Conceal and seal the nodes at the tensioning end.

[0174] In this embodiment of the invention, to apply prestress to the concrete beam, a tensioning device is used to tension the prestressed steel bars or strands. The magnitude and direction of the tension force should be in accordance with the design requirements. Prestressing can improve the load-bearing capacity and crack resistance of the concrete beam. To protect the prestressed steel bars or strands and ensure their bond with the concrete beam, the cavity inside the corrugated pipe is grouted after tensioning. Grouting prevents moisture and other harmful substances from corroding the prestressed steel bars or strands, while also improving the bond with the concrete beam and ensuring the transfer of prestress. To maintain the cleanliness and aesthetics of the concrete beam, after grouting is completed and the strength meets the requirements, excess steel strands exposed on the concrete surface are cut off. This prevents injury to personnel from the steel strands and maintains the cleanliness and aesthetics of the concrete beam. To protect the tensioning end joints, the joints are concealed and sealed. This prevents corrosion of the steel bars or strands at the joints and also prevents leakage of the grout, ensuring the stability and durability of the concrete beam.

[0175] In a preferred embodiment of the present invention, step 171 above may include:

[0176] Step 1711: Inspect the tensioning equipment to ensure it is in good working order;

[0177] Step 1712: Assemble the tensioning device onto one end of the prestressed steel bar or steel strand;

[0178] Step 1713: Start the equipment to tension the prestressed steel bars or steel strands.

[0179] In this embodiment of the invention, to ensure the normal operation and construction safety of the tensioning equipment, the equipment is inspected, including its integrity and working condition, to ensure it is in good working order. This process can prevent construction errors or safety accidents caused by equipment problems. Before tensioning, the tensioning equipment is assembled to one end of the prestressed steel bars or strands. This is the preliminary preparation for tensioning; correct assembly ensures accurate application of tension force and smooth tensioning operation. The tensioning operation is then carried out on the prestressed steel bars or strands. The equipment is started to tension the prestressed steel bars or strands. The force applied by the equipment induces prestress in the steel bars or strands, thereby improving the load-bearing capacity and durability of the concrete beam.

[0180] During the tensioning of the prestressed beam of this invention, a jack (model YC-250) is selected for whole-bundle tensioning based on the operating space at the tensioning end; the elongation value at the tensioning end is the actual elongation value of the prestressed beam. The prestressed beam tensioning process involves staged tensioning. The tensioning control stress for a single prestressing tendon is σcon = XX MPa, with a 3% over-tensioning. The tensioning stresses during each stage of staged tensioning are shown in the table below:

[0181] Tension stress tables at various levels

[0182] Classification 20% σcon 60% σcon 1.03σcon

[0183] In a preferred embodiment of the present invention, tensioning of the reinforcing bar or steel strand includes:

[0184] Using force and displacement indicators, the tension force and elongation of prestressed steel bars or strands can be monitored in real time.

[0185] The monitored data is recorded and compared with the design requirements. If the actual tension or elongation does not meet the design requirements, tensioning is stopped. If the actual tension or elongation exceeds the design requirements, the tension is reduced by adjusting the equipment until the design requirements are met.

[0186] In this embodiment of the invention, force and displacement indicators are used to monitor the tension force and the elongation of the prestressed steel bars or strands in real time. Precise control of the tension force and the elongation of the bars or strands, ensuring they remain within the design range, is crucial for the quality and performance of the prestressed concrete beam. The monitored data is recorded to guarantee construction quality and to facilitate tracking and investigation in case of problems. Recording data allows for a better understanding of the construction process, providing experience and reference for future construction. The monitored data is compared with the design requirements. If the actual tension force or elongation does not meet the design requirements, tensioning is stopped to prevent structural problems caused by insufficient tension or elongation. If the actual tension force or elongation exceeds the design requirements, the equipment is adjusted to reduce the tension force until the design requirements are met. This is to prevent structural problems caused by excessive tension or elongation. Through this process, the quality and performance of the prestressed concrete beam are ensured.

[0187] During construction, reinforcement should be laid out in a curved pattern according to design requirements, ensuring that the final control point height in the vertical direction meets design requirements. The curve should be smooth, and the location of the inflection point should be constructed according to the drawing. The anchorage bearing plate at the tensioning end must be reliably fixed, and the tensioning line must be perpendicular to the bearing plate surface. The radius of curvature of the prestressed steel strands should not be less than 5m. The prestressed tendons in the beam should be symmetrically arranged within the beam section. When there is a conflict between the placement of non-prestressed tendons and prestressed tendons, the position of the non-prestressed tendons should be adjusted in consultation with the design team to ensure the position and shape of the prestressed tendons. When the spacing between the prestressed steel strands is small or the stirrups in the beam and column are dense, the spiral reinforcement under the anchorage must be replaced with welded steel mesh, and the local bearing capacity must be verified. Tie bars should be placed after the prestressed tendons are threaded through the beam. The longitudinal reinforcement of secondary beams that intersect the prestressed beam perpendicularly must not be positioned against the corrugated pipe.

[0188] The concrete at the tensioning end and the fixed end should be vibrated carefully, and missed vibration is strictly prohibited to avoid honeycomb and pitting. When pouring concrete, avoid direct impact of the vibrator on the prestressed corrugated pipe. The water-cement ratio of the concrete must be controlled and it must be vibrated to ensure compaction. Proper on-site curing should be carried out to prevent early cracking. Before the initial setting of the concrete, the surface of the concrete should be swept and compacted to reduce shrinkage cracks.

[0189] When tensioning prestressed beams, a jack (model YC-250) is selected based on the operating space at the tensioning end for whole-bundle tensioning; the elongation value at the tensioning end is the actual elongation value of the prestressed beam. The prestressed beam tensioning process involves staged tensioning, and the tensioning stress at each stage is shown in the table below.

[0190] When setting up formwork for prestressed beams, cambering is required. Prestressing tendons can only be tensioned after the concrete strength reaches 100% of the design value and meets the tensioning conditions. Prestressing tensioning should adhere to the principle of symmetry; prestressing tendons in the same beam should be tensioned simultaneously. Deformation and cracking of the beam should be monitored during tensioning. If abnormalities such as excessive deflection or cracking are encountered, tensioning should be stopped immediately and resumed only after analysis and treatment. After tensioning, the ducts should be filled with special grout with a strength grade ≥ M45. The grouting should be full and dense; admixtures in the grout must not contain chlorides, sulfides, or nitrates that are corrosive to prestressing tendons. The formwork for the prestressed section can only be removed after tensioning and grouting are completed and the strength reaches 100% of the design value.

[0191] In a preferred embodiment of the present invention, the tension force is calculated based on construction error, material type, temperature, humidity, and stress relaxation, wherein the formula for the tension force is:

[0192] F=A*σ*(1-R)*(1+αT+βH)*(1-η)*(1+ε), where ε is the construction error, which can determine the force that needs to be applied to the prestressed steel bars or steel strands during construction, and can more accurately calculate the required tension force;

[0193] The elongation is calculated based on construction errors, friction losses, initial stress, and changes in the material's elastic modulus. The formula for calculating the elongation is as follows:

[0194] ΔL=L*(σ i +Δσ-μF) / E'×(1+ε) can predict the elongation of prestressed steel bars or steel strands after force is applied, which can better control the construction process and avoid engineering problems caused by excessive or insufficient elongation.

[0195] The modulus of elasticity is calculated based on durability, anchoring system, and environmental impact. The formula for calculating the modulus of elasticity is as follows:

[0196] E'=E / (1+ψT+φH)*(1-ζ)*(1-δ), where δ is the elastic modulus adjustment coefficient caused by the reduction of material durability. It can help us understand the rebound of the material after being subjected to force and can more accurately predict the rebound of steel bars or steel strands after being subjected to force.

[0197] Where F is the tension force, A is the cross-sectional area of ​​the prestressed steel bar or strand, σ is the tensile strength of the steel bar or strand, R is the stress relaxation rate, α is the coefficient of thermal expansion of the material, T is the temperature change, β is the coefficient of thermal expansion of the material, H is the humidity change, η is the stress adjustment coefficient due to different types of steel bars or strands, ε is the construction error, ΔL is the elongation of the steel bar or strand, L is the original length of the steel bar or strand, and σ i denoted as the initial stress of the reinforcing bar or steel strand; Δσ as the stress change; μ as the friction coefficient; E' as the actual elastic modulus of the material; E as the standard elastic modulus of the material; ψ as the temperature elastic modulus coefficient of the material; φ as the humidity elastic modulus coefficient of the material; ζ as the elastic modulus adjustment coefficient caused by the anchoring system; and δ as the elastic modulus adjustment coefficient caused by the reduction in material durability.

[0198] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A large-span prestressed steel-concrete composite structure, characterized in that, include: The composite beam (1) is composed of a concrete beam and an I-beam (2), and the two ends of the concrete beam and the I-beam (2) are integrally cast with the frame column (4); The prestressed corrugated pipe (3) is integrally cast with the concrete beam, and one end of the prestressed corrugated pipe (3) is a fixed end (6), and the other end is a tensioning end (5); it also includes: The exhaust port (7) extends into the composite beam (1) at one end and out of the composite beam (1) at the other end; A horizontal turning point (11) is provided at the junction of the prestressed corrugated pipe (3) and the frame column (4); it also includes: The inflection point (8) is set on the prestressed corrugated pipe (3); Grouting holes (9) are set in the middle of the composite beam (1); the tensioning end of the prestressed frame beam is arranged outside the core area of ​​the beam and column by using the method of horizontal haunching on the side of the beam; the tensioning end of the prestressed secondary beam is arranged outside the supporting beam by using the method of exposed anchorage; the horizontal haunches are equipped with top additional steel bars, bottom additional steel bars, web additional steel bars and stirrups to achieve local bearing pressure of the horizontal haunches; Connecting plates or sleeves are added at the stiffening plate positions within the columns to connect with the second and third rows of reinforcing bars; stirrup connecting plates are installed on the web of the box-type steel beam, and the stirrups are welded to the stirrup connecting plates; when bent reinforcing bars encounter the web of the box-type steel beam, perforated straight reinforcing bars pass through, passing through the webs on both sides of the box-type beam and the web of the column; U-shaped prestressed tendon positioning bars fix the corrugated pipes to the steel pipes, and the U-shaped prestressed tendon positioning bars are welded to the web of the steel pipes on one side with a 10d weld, and the distance between adjacent prestressed tendon positioning bars is ≤1000mm; It also includes: A steel mesh (10) is connected to a tensioning end (5) extending to the outside of the frame column (4); a prestressed tendon (23) is provided inside the prestressed corrugated pipe (3), and the tensioning end (5) includes: Anchor plate (26) is fitted on the outside of the prestressed corrugated pipe (3); Spiral reinforcement (21) is wound around the outside of the anchor plate (26); Anchor plate (24) is connected to the anchor pad plate (26) and to the prestressing tendon (23); The sealing end (25) is connected to the prestressed tendon (23) and the anchor plate (24); The fixed reinforcing bar (22) is connected to the anchor plate (26) and the prestressed tendon (23).

2. A construction method for a large-span prestressed steel-concrete composite structure as described in claim 1, characterized in that, The construction method includes the following steps: The steel columns and steel beam frame columns are hoisted to the designated positions and welded to construct the building's frame columns; On the foundation of the frame columns, a prestressed concrete beam support scaffold is erected, and the bottom formwork of the beam is erected to create an arch and the bottom elevation of the beam is calibrated to form a support structure. On the supporting structure, a non-prestressed steel reinforcement skeleton is tied, while the prestressed material is transported to the designated location; Using the prestressed materials that have been transported to the designated location, install and fix the prestressed positioning steel bars, install the prestressed corrugated pipes and insert the prestressed steel strands, and install and fix the prestressed tensioning end and anchorage end nodes to form a prestressed system. After the prestressed system is installed, non-prestressed steel bars, professional pipelines, and prestressed concrete beam formwork are installed. After the installation of all prestressed and non-prestressed systems is completed, a concealed inspection is carried out, and concrete is poured. Once the concrete reaches the tension design strength, the beam end formwork is removed. After the concrete strength meets the requirements, prestressing is carried out, the ducts are grouted, excess exposed steel strands are cut off, and the tensioning end nodes are concealed and sealed.

3. The construction method for large-span prestressed steel-concrete composite structures according to claim 2, characterized in that, The steel columns and steel beam frame columns are hoisted to the designated positions and welded to construct the building's frame columns, including: Based on the architectural design drawings, calculate and determine the dimensions, quantity, and location of the steel columns and beams; The steel is cut and shaped to produce steel columns and beams that meet the design requirements, and the manufactured steel columns and beams are transported to the construction site. Use a crane to lift the steel columns and beams to the positions specified in the design; Welding equipment is used to weld steel columns and beams together to construct the building's frame columns.

4. The construction method for large-span prestressed steel-concrete composite structures according to claim 3, characterized in that, On the foundation of the frame columns, a prestressed concrete beam support scaffolding is erected, and simultaneously, the beam bottom formwork is erected, cambering is performed, and the beam bottom elevation is calibrated to form the support structure, including: According to the design drawings and construction requirements, erect the prestressed concrete beam support scaffolding; Install the bottom formwork of the beam on the scaffolding, and carry out the cambering operation of the bottom formwork of the beam according to the design and site conditions; Use measuring equipment to calibrate the elevation of the bottom formwork of the beam.

5. The construction method for large-span prestressed steel-concrete composite structures according to claim 4, characterized in that, On the supporting structure, a non-prestressed steel reinforcement cage is tied, and prestressed materials are transported to a designated location, including: According to the design drawings and construction specifications, the non-prestressed steel bars are tied in the prescribed manner and sequence to form a skeleton; After the non-prestressed steel reinforcement cage is tied, the prestressed steel bars or strands, anchors, and corrugated pipes are transported to the construction site according to the positions and quantities required by the drawings.

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