Frame composed of steel reinforced concrete columns and prestressed steel reinforced concrete beams and construction method

Abstract

The invention discloses a frame composed of steel reinforced concrete columns and prestressed steel reinforced concrete beams and a construction method, and belongs to the technical field of structural engineering.The frame comprises the steel reinforced concrete beams and the steel reinforced concrete columns, and a plurality of prestressed tendons are arranged in the steel reinforced concrete beams; the steel reinforced concrete beam comprises beam profile steel and a beam steel reinforcement framework, and the prestressed tendons are symmetrically distributed on the outer side of a beam flange plate of the beam profile steel with a beam web of the beam profile steel as the center. The high prestressed tendons along the beam are divided into a plurality of rows with different elevations; the prestressed tendons are symmetrically arranged relative to the axial midpoint of the steel reinforced concrete beam; the steel reinforced concrete column comprises column-shaped steel, the column-shaped steel comprises a cross-shaped web plate, and holes are formed in the corresponding positions of the cross-shaped web plate in advance and used for the prestressed tendons to penetrate through. The prestressed tendons are retard-bonded prestressed tendons. The retard-bonded prestressed tendons are arranged on the two sides of the beam flange plate, the size of holes in the column type steel is reduced, damage of the holes to the column type steel is reduced, and the construction procedures of pre-burying pipelines and grouting are reduced; and a tensioning end haunch is not arranged at the node any more, so that the concrete consumption is reduced.

Description

Technical Field

[0001] This invention belongs to the field of structural engineering technology, specifically relating to a frame composed of steel-concrete composite columns and prestressed steel-concrete composite beams and its construction method. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Large-span structures are typically found in the roofs of public buildings such as conference rooms, lecture halls, atriums, theaters, cinemas, restaurants, and indoor sports fields, with spans ranging from 20 to 35 meters. These structures are mostly frame-concrete composite (PCC) structural systems, and their main design objectives are to reduce self-weight, control deflection and cracking, and meet requirements for good floor comfort.

[0004] To achieve the above requirements, existing technology discloses a large-span prestressed steel-concrete composite structure, including frame columns and beams. Both the frame columns and beams adopt a steel-concrete composite structure, and the beams are fabricated using pre-installed duct reinforcement and post-tensioning. Prestressing design improves the tensile strength and bearing capacity of the concrete under load, prevents or delays cracking, increases structural stiffness, and optimizes cross-sectional dimensions to save material usage.

[0005] The above solution has the following problems: The prestressed tendon scheme using pre-installed ducts and grouting requires drilling holes in the steel-concrete composite column to insert the prestressed tendons. The large diameter of the prestressed tendons reduces the stiffness and load-bearing capacity of the column steel and causes stress concentration. Furthermore, after the prestressed tendons pass through the joint area for a certain distance, additional tensioning ends and haunches are set on both sides of the beam for tensioning the prestressed tendons, which affects the aesthetics and is not conducive to saving concrete usage. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a frame composed of steel-concrete composite columns and prestressed steel-concrete composite beams and a construction method thereof. The structural composition of the frame can solve the problems in the prior art where the pre-set ducts for reinforcing bars cause a decrease in the stiffness and bearing capacity of the column steel and stress concentration, while the addition of haunches at the tensioning ends affects the aesthetics and is not conducive to saving concrete usage.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, a frame composed of steel-concrete composite columns and prestressed steel-concrete composite beams is provided, including steel-concrete composite beams and steel-concrete composite columns, wherein multiple prestressing tendons are provided in the steel-concrete composite beams, and the two ends of the prestressing tendons pass through the steel-concrete composite columns and are connected to anchorages. A steel-concrete composite beam consists of beam steel sections and a beam reinforcement cage. The beam steel section includes a beam web, with beam flanges fixed at both the upper and lower ends of the beam web. Multiple prestressing tendons are symmetrically distributed on the outer side of the beam flanges with the beam web as the center. Along the beam height from bottom to top, the prestressing tendons are divided into multiple rows at different elevations. The middle part of each prestressing tendon is located at the bottom of the middle section of the steel-concrete beam, and each prestressing tendon is symmetrically arranged with respect to the axial midpoint of the steel-concrete beam; before pouring, the bottom formwork at the middle section of the steel-concrete beam is arched. The steel-concrete composite column includes column steel and column reinforcement cage. The column steel includes cross-shaped web and column flange plates at the ends of the cross-shaped web. Holes are pre-drilled at corresponding positions in the cross-shaped web for the prestressing tendons to pass through. The prestressing tendons are slow-bonded prestressing tendons.

[0008] Preferably, the beam reinforcement cage includes bottom reinforcement, web reinforcement, top reinforcement, and several stirrups arranged along the axial direction of the steel-concrete beam, with the bottom reinforcement, web reinforcement, and top reinforcement tied to the stirrups; the column reinforcement cage includes longitudinal reinforcement, with several stirrups arranged along the axial direction of the steel-concrete column, and the longitudinal reinforcement tied to the stirrups.

[0009] Preferably, the beam web reinforcement is fixed by beam tie bars; the beam tie bars are welded to the beam web, or multiple through holes are evenly opened on the beam web along the beam axis, and the beam tie bars pass through the through holes to connect to the beam web reinforcement.

[0010] Preferably, multiple studs are fixed on the upper and lower ends of the beam web, on both sides of the beam web, and on the outer side of the column flange.

[0011] Preferably, the beam steel is welded and fixed to the outer side of the column flange plate; the column steel is fixed with reinforcing ribs at the elevation of the upper beam flange plate and the elevation of the lower beam flange plate, and the reinforcing ribs are fixedly connected to the column flange plate and the cross web plate; the beam flange plate is fixed with a steel bar connector for connecting the column longitudinal reinforcement, and a reinforcing plate is set at the connection of the longitudinal reinforcement.

[0012] Preferably, steel bar connectors are welded to the column flange plate, and some of the top or bottom reinforcement bars of the beam are connected to the column flange plate through the steel bar connectors. Some of the top or bottom reinforcement bars of the beam are directly anchored into the steel-concrete column from both sides of the column flange plate.

[0013] Preferably, when the lateral force resisting frame is a single-span frame, the connection node between the steel-concrete beam and the steel-concrete column is a T-joint point; at the T-joint point, the prestressing tendons are anchored on the side of the steel-concrete column away from the steel-concrete beam; the prestressing tendons are locked after tensioning is completed.

[0014] Preferably, when the lateral force resisting frame is a multi-span frame, the connection node between the steel-concrete beam and the steel-concrete column is a cross node; the cross node has multiple tensioning slots reserved in the stirrup reinforcement zone of the adjacent span, and the anchorages at the ends of the prestressing tendons are set in the tensioning slots.

[0015] Preferably, tensioning slots with the same number of prestressing tendons are provided on the adjacent span beams of the cross node; the tensioning slots corresponding to the prestressing tendons on different sides are staggered; the tensioning slots corresponding to the lower row of prestressing tendons on the same side are set away from the steel-concrete composite column, and the tensioning slots corresponding to the upper row of prestressing tendons on the same side are set close to the steel-concrete composite column.

[0016] Secondly, a construction method for the aforementioned frame composed of steel-concrete composite columns and prestressed steel-concrete composite beams is provided, with the specific steps as follows: Prepare column steel and beam steel in advance; while installing column steel, tie column longitudinal reinforcement and column stirrups, reserve connection nodes with steel-concrete beams, and support and pour steel-concrete columns. Once the steel-concrete composite column reaches the required strength, the bottom formwork of the beam is erected, and the beam bottom elevation is adjusted by cambering the middle section of the beam. The beam steel is then installed, the steel reinforcement cage of the steel-concrete composite beam is tied, and the beam steel, the steel reinforcement cage of the steel-concrete composite beam, and the column steel are connected. Position and fix the prestressing tendons, pass them through the column steel connecting anchors, and fix the anchors at the same time; erect the node end formwork and the side formwork of the steel-concrete beam, and pour the steel-concrete beam concrete; Once the concrete strength of the steel-concrete beam reaches the required level, the end formwork of the joint and the side formwork of the steel-concrete beam are removed. After the prestressing tendons are tensioned to the required level, the prestressing tendons are locked and anchored.

[0017] Compared with the prior art, the advantages and positive effects of this invention are: This invention reduces the size of the openings in the column steel by setting slow-bonding prestressing tendons on both sides of the beam flange, thus reducing damage to the column steel. By setting multiple rows of prestressing tendons, the prestressing can be applied while reducing the construction steps of embedded pipes and grouting. At the joint, there is no need to set tensioning end haunches. Tensioning is carried out directly on the side of the steel-concrete column or in the adjacent span beam, saving concrete usage. Attached Figure Description

[0018] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0019] Figure 1 This is a front view of a single-span frame in the framework of Embodiment 1 or 2 of the present invention; Figure 2 This is embodiment 1 or 2 of the present invention. Figure 1 Schematic diagram of AA section in the middle; Figure 3 This is a bottom schematic diagram of a single-span frame T-byte point in Embodiment 1 or 2 of the present invention; Figure 4 This is a top view of a single-span frame T-byte point in Embodiment 1 or 2 of the present invention; Figure 5 This is a front view of a single-span frame T-byte point in Embodiment 1 or 2 of the present invention; Figure 6 This is a side view of a single-span frame T-byte point in Embodiment 1 or 2 of the present invention; Figure 7 This is a front view of the multi-span frame in the framework of Embodiment 1 or 2 of the present invention; Figure 8 This is a bottom schematic diagram of the cross node of the multi-span frame in Embodiment 1 or 2 of the present invention; Figure 9 This is a top schematic diagram of the cross node of the multi-span frame in Embodiment 1 or 2 of the present invention; Figure 10 This is a front view of the cross node of the multi-span frame in Embodiment 1 or 2 of the present invention; In the picture: 1. Bottom reinforcement of beam; 2. Bottom stud; 3. Beam steel; 4. Prestressed tendon; 5. Waist stud; 6. Beam waist reinforcement; 7. Beam stirrup; 8. Beam top reinforcement; 9. Top stud; 10. Reinforcing plate; 11. Beam tie bar; 12. Column longitudinal reinforcement; 13. Column stirrup; 14. Column steel; 15. Shear stud; 16. Reinforcing rib; 17. Tensioning groove; 18. Anchorage; 19. Rebar connector. Detailed Implementation

[0020] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0021] The present invention will now be described in detail with reference to the accompanying drawings.

[0022] Example 1 This embodiment discloses a frame composed of steel-concrete composite columns and prestressed steel-concrete composite beams, such as... Figure 1 , Figure 7 As shown, it is divided into single-span frame and multi-span frame, both of which include steel-concrete beams and steel-concrete columns; multiple prestressed tendons 4 are set in the steel-concrete beams, and the two ends of the prestressed tendons 4 pass through the steel-concrete columns and are connected to anchorages 18.

[0023] like Figure 1 , Figure 2 , Figure 4 , Figure 7 , Figure 9As shown, the steel-concrete composite beam includes beam steel section 3 and beam reinforcement cage. Beam steel section 3 includes a beam web, with the upper and lower ends of the beam web fixed to the beam flange. Multiple prestressing tendons 4 are symmetrically distributed on the outer side of the beam flange with the beam web as the center, that is, multiple prestressing tendons 4 are symmetrical along the axis of the steel-concrete composite beam. On both sides of the beam web, along the height of the beam from bottom to top, the prestressing tendons 4 are divided into multiple rows with different elevations. The tensioning slots corresponding to the prestressing tendons on different sides are staggered. The tensioning slots corresponding to the upper and lower rows of prestressing tendons on the same side are also staggered, which can avoid excessive tension stress causing stress concentration in the beam. The tensioning slots are not large in size and do not protrude outward from the beam body after being sealed and anchored. The distance between the prestressing tendons 4 in the same row and the axis of the steel-concrete composite beam is different.

[0024] like Figure 2 As shown, in this embodiment, there are eight prestressing tendons 4. These eight prestressing tendons 4 are symmetrical along the axis of the steel-concrete beam, with four prestressing tendons 4 on each side of the axis. Figure 4 , Figure 9 As shown, along the beam's height from bottom to top, the four prestressing tendons 4 are divided into two rows at different elevations, with the distances between the prestressing tendons 4 and the axis of the steel-concrete beam varying within the same row. The prestressing tendons closer to the axis of the steel-concrete beam are the inner prestressing tendons, while those farther away are the outer prestressing tendons. It is understandable that placing the prestressing tendons 4 on both sides of the beam flange facilitates positioning and fixing during the construction binding process.

[0025] like Figure 1 , Figure 7 As shown, the middle part of each prestressing tendon 4 is located at the bottom of the middle section of the steel-concrete beam, and each prestressing tendon 4 should be symmetrically arranged with respect to the axial midpoint of the steel-concrete beam; thus, in space, the prestressing tendons 4 form a double-symmetrical structure, ensuring uniform distribution of prestress during tensioning. In addition, before pouring, the bottom formwork at the middle section of the steel-concrete beam is arched, so that the anti-arching effect of the prestressing tendons 4 can effectively reduce the equivalent bending moment of the steel-concrete beam, thereby reducing the mid-span deflection.

[0026] like Figure 1 , Figure 7 As shown, the steel-concrete composite column includes column steel section 14 and column reinforcement cage, with prestressed tendons 4 passing through and anchored to the column steel section 14; as Figure 3 , Figure 4 , Figure 8 , Figure 9 As shown, the column steel 14 includes a cross web and column flanges at the ends of the cross web. Holes are pre-drilled at corresponding positions in the cross web for the prestressing tendons 4 to pass through.

[0027] The prestressing tendon 4 is a slow-bonding prestressing tendon (composed of prestressing steel bars coated with a slow-setting adhesive). During the construction phase, the prestressing tendon 4 does not bond with the surrounding slow-setting adhesive. However, within a predetermined period after the completion of construction, the prestressing tendon 4 bonds with the surrounding concrete through the cured slow-setting adhesive.

[0028] In this embodiment, the prestressing tendon 4 is a slow-bonded prestressing tendon. Compared with the method of setting ducts and then inserting prestressing tendons, the size of the opening on the column steel can be reduced, and the damage of the opening to the column steel can be reduced.

[0029] In this embodiment, the lateral force resisting frame consists of steel-concrete composite columns and steel-concrete composite beams. In terms of deflection control, the prestressing effect of the prestressing tendons on the concrete in the tension zone of the steel-concrete composite beams allows more concrete in the compression zone to participate in the calculation of the beam's bending stiffness, thereby improving the overall bending stiffness of the beam.

[0030] Furthermore, because the middle of prestressing tendon 4 is located at the bottom of the middle section of the steel-concrete beam, and its two ends are symmetrically positioned at the top of both ends of the beam, the anti-camber effect of the prestressing tendons effectively reduces the equivalent bending moment of the beam, thereby reducing mid-span deflection. Its deflection control efficiency is higher than that of ordinary beams, steel beams, and steel-concrete beams. In terms of crack control, steel-concrete beams can directly apply compressive stress to the concrete in the tension zone, further reducing tensile strain and crack width. Compared to ordinary beams, steel beams, and steel-concrete beams, prestressed concrete beams are more direct and effective in reducing crack width.

[0031] like Figure 1 , Figure 2 , Figure 4 As shown, the beam reinforcement cage includes several bottom reinforcement bars 1, web reinforcement bars 6, and top reinforcement bars 8. The bottom reinforcement bars 1 are located at the bottom of the steel-concrete beam, and the top reinforcement bars 8 are located at the top. Multiple web reinforcement bars 6 are installed along the beam's height, and multiple stirrups 7 are installed along the beam's axial direction. The bottom reinforcement bars 1, web reinforcement bars 6, and top reinforcement bars 8 are tied and fixed to the stirrups 7 to form the reinforcement cage of the steel-concrete beam. Multiple prestressed tendons 4 are tied to predetermined positions within the reinforcement cage of the steel-concrete beam.

[0032] like Figure 1 , Figure 5 , Figure 6 , Figure 7 , Figure 10 As shown, the steel-concrete composite column also includes several longitudinal reinforcement bars 12, which are evenly distributed on the outer circumference of the column steel 14. Several column stirrups 13 are arranged along the axial direction of the steel-concrete composite column. The longitudinal reinforcement bars 12 and the column stirrups 13 are tied and fixed to form a stable steel reinforcement skeleton of the steel-concrete composite column.

[0033] like Figure 2As shown, the web reinforcement 6 on both sides of the beam steel 3 is fixed by beam tie bars 11; the beam tie bars 11 can be welded to the beam web. In some embodiments, multiple through holes are evenly opened in the beam web along the beam axis, and the beam tie bars 11 pass through the through holes to connect the web reinforcement 6; it can be understood that, because the beam bears pressure, the beam web is set perpendicular to the roof. The through holes in the beam web also facilitate the flow of concrete on both sides of the beam steel 3 during concrete pouring, making the pouring denser.

[0034] like Figure 2 As shown, multiple bottom studs 2 are fixedly installed on the lower end beam flange plate, multiple top studs 9 are fixedly installed on the upper end beam flange plate, and multiple waist studs 5 are fixed on both sides of the beam web plate; as shown Figure 1 As shown, shear studs 15 are also provided on the outer side of the column flange plate. The studs are used to strengthen the connection between the column steel 14, the beam steel 3 and the concrete.

[0035] like Figure 3 , Figure 4 , Figure 8 , Figure 9 As shown, the cross-shaped web is composed of a first web and a second web welded and fixedly connected perpendicularly to each other. The first web is set parallel to the steel-concrete beam, and the second web is set perpendicular to the steel-concrete beam. Multiple through holes are made at corresponding positions in the second web for the prestressing tendons 4 to pass through. In this embodiment, since the prestressing tendons 4 are loosely bonded prestressing tendons, compared to setting ducts and then inserting the prestressing tendons, the size of the openings in the second web can be reduced, thereby reducing damage to the column steel caused by the openings. To enhance the strength of the second web, reinforcing steel plates can also be welded to both sides at the through holes in the second web.

[0036] like Figure 1 , Figure 5 , Figure 7 , Figure 8 As shown, when the steel-concrete column is connected to the steel-concrete beam, the outer side of the column flange plate of the beam steel 3 and the column steel 14 is welded and fixed; the bottom reinforcement 1, the web reinforcement 6, and the top reinforcement 8 of the beam extend into the steel-concrete column and are fixed to ensure the connection strength between the steel-concrete beam and the steel-concrete column. Reinforcing ribs 16 are fixed to the column steel 14 at the elevation of the upper and lower beam flange plates, and the reinforcing ribs 16 are fixedly connected to the column flange plate and the cross web plate; these reinforcing ribs strengthen the connection between the column flange plate and the cross web plate, thereby also ensuring the connection strength between the column flange plate and the beam steel 3.

[0037] like Figure 3 , Figure 8As shown, since the beam steel 3 and the column steel 14 are welded and fixed to the outer side of the column flange plate, the column longitudinal reinforcement 12 passes through the upper and lower beam flange plates of the beam steel 3. Therefore, it is necessary to set the reinforcement connector 19 (such as the connecting sleeve) on the upper and lower beam flange plates. In order to strengthen the connection and ensure the strength of the beam steel 3, the reinforcement plate 10 is set at the longitudinal reinforcement connection.

[0038] like Figure 3 , Figure 8 As shown, a steel bar connector 19 (such as a connecting sleeve) is welded onto the column flange plate. Some of the top or bottom reinforcement bars of the beam are connected to the column flange plate through the steel bar connector 19, and some of the top or bottom reinforcement bars of the beam are directly anchored into the steel-concrete column from both sides of the column flange plate; thus realizing the connection between the steel-concrete beam reinforcement cage and the steel-concrete column.

[0039] like Figure 1 , Figure 7 As shown, the prestressing tendon 4 is located below the top reinforcement 8 of the beam. After passing through the cross web, the anchor 18 is installed. After the steel-concrete column and steel-concrete beam are poured and cured, the steel-concrete beam is tensioned through one end of the anchor 18 to apply prestress.

[0040] In this embodiment, the DZM single-hole tensioning anchoring system is adopted. The anchor 18 at the tensioning and sealing end includes a wedge, an anchor ring, a wedge anchor plate, a spiral reinforcement, and a cavity mold. It should be noted that the anchor 18 of the present invention is not limited to the DZM single-hole tensioning anchoring system. In other embodiments, other types of anchors can also be used, such as upset head anchors, nut anchors, etc.

[0041] In this embodiment, the prestressing tendon 4 can be tensioned at one end, i.e., one end of the prestressing tendon 4 is the tensioning and anchoring end, and the other end is the fixed end, which adopts a compression anchor. Alternatively, tensioning can be performed at both ends of the prestressing tendon 4, with tensioning first at one end and then supplementary tensioning at the other end, reducing frictional loss.

[0042] like Figures 1 to 6 As shown, when the lateral force resisting frame is a single-span frame, the connection node between the steel-concrete beam and the steel-concrete column is the T-joint point; at the T-joint point, the prestressing tendon 4 is anchored 18 on the side of the steel-concrete column away from the steel-concrete beam; the prestressing tendon 4 is locked after tensioning is completed.

[0043] like Figures 7 to 10 As shown, when the lateral force resisting frame is a multi-span frame, the connection node between the steel-concrete beam and the steel-concrete column is a cross node; the difference from the T-shaped node is that the cross node has multiple tensioning slots 17 reserved in the stirrup reinforcement zone of the beam in the adjacent span, and one end of a prestressing tendon 4 is set in each tensioning slot 17, and the anchor 18 at the end of the prestressing tendon 4 is set in the tensioning slot 17.

[0044] Based on the number of prestressing tendons 4, the same number of tensioning slots 17 are set on the adjacent span beams at the cross joint; the tensioning slots 17 corresponding to the prestressing tendons 4 on different sides are pre-set on both sides of the axis of the adjacent span beam, and the tensioning slots 17 on one side and the other side are staggered along the axis of the adjacent span beam; the tensioning slots corresponding to the lower row of prestressing tendons on the same side are set away from the steel-concrete composite column, and the tensioning slots corresponding to the upper row of prestressing tendons on the same side are set close to the steel-concrete composite column. The reason for this design is to facilitate the zonal tensioning of each prestressing tendon 4 after the pouring and curing are completed, to avoid stress concentration on the beam, and to ensure that the adjacent span beams are not damaged.

[0045] In this embodiment, eight tensioning slots 17 are provided. According to the arrangement of the prestressing tendons 4, the tensioning slots 17 are divided into four groups, with two slots in each group. The four groups of tensioning slots 17 are respectively preset on both sides of the axis of the adjacent span beam, and the tensioning slots 17 on one side and the other side are staggered along the axis of the adjacent span beam.

[0046] like Figure 9 As shown, the tensioning slots 17 of the two groups on the same side are arranged such that the tensioning slot 17 corresponding to the lower row of prestressing tendons 4 is located on the current side away from the steel-concrete composite column; the tensioning slot 17 corresponding to the upper row of prestressing tendons 4 is located on the current side closer to the steel-concrete composite column. The two ends of the prestressing tendons 4 extend into the tensioning slots 17 of the adjacent span for anchoring.

[0047] It should be noted that the span of the span adjacent to the current large span in a multi-span frame is a normal span.

[0048] In this embodiment, the prestressed concrete beam has a strength grade of not less than C40, and the prestressing tendons are made of high-strength, low-relaxation grade steel strands φs12.6 (or similar materials), with a structural form of (1×7) seven strands, an ultimate strength standard value of fptk=1860MPa, and a cross-sectional area of ​​313mm². 2 The steel profiles inside the beams and columns are made of Q355-B grade. (It should be noted that in other embodiments, other types of steel profiles, prestressing tendons, and concrete strength can be selected according to design requirements and the magnitude of prestress.)

[0049] Example 2 This embodiment discloses a construction method for a frame composed of steel-concrete composite columns and prestressed steel-concrete composite beams. It applies the frame composed of steel-concrete composite columns and prestressed steel-concrete composite beams disclosed in Embodiment 1. The specific steps are as follows: Prepare column steel 14 and beam steel 3 in advance; install column steel 14, and at the same time tie column longitudinal reinforcement and column stirrups, reserve connection nodes with steel-concrete beams, and formwork and pour steel-concrete columns. Once the steel-concrete composite column reaches the required strength, the bottom formwork of the beam is erected, and the beam bottom elevation is adjusted by cambering the middle section of the beam. Install beam steel 3, tie the steel reinforcement cage of the steel-concrete beam, and connect beam steel 3, the steel reinforcement cage of the steel-concrete beam, and column steel; locate the position of the prestressing tendons and fix the prestressing tendons, so that the prestressing tendons pass through the column steel and connect to the anchorage, and fix the anchorage at the same time; Erect the end formwork of the nodes and the side formwork of the steel-concrete beam, and pour the concrete for the steel-concrete beam; Once the concrete strength of the steel-concrete beam reaches the required level, the end formwork of the joint and the side formwork of the steel-concrete beam are removed. After the prestressing tendons are tensioned to the required level, the prestressing tendons are locked and anchored.

[0050] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A frame composed of steel-concrete composite columns and prestressed steel-concrete composite beams, characterized in that, It includes steel-concrete beams and steel-concrete columns. Multiple prestressed tendons are installed inside the steel-concrete beams, and the two ends of the prestressed tendons pass through the steel-concrete columns and are connected to anchorages. A steel-concrete composite beam consists of beam steel sections and a beam reinforcement cage. The beam steel section includes a beam web, with beam flanges fixed at both the upper and lower ends of the beam web. Multiple prestressing tendons are symmetrically distributed on the outer side of the beam flanges with the beam web as the center. Along the beam height from bottom to top, the prestressing tendons are divided into multiple rows at different elevations. The middle part of each prestressing tendon is located at the bottom of the middle section of the steel-concrete beam, and each prestressing tendon is symmetrically arranged with respect to the axial midpoint of the steel-concrete beam; before pouring, the bottom formwork at the middle section of the steel-concrete beam is arched. The steel-concrete composite column includes column steel and column reinforcement cage. The column steel includes cross-shaped web and column flange plates at the ends of the cross-shaped web. Holes are pre-drilled at corresponding positions in the cross-shaped web for the prestressing tendons to pass through. The prestressing tendons are slow-bonded prestressing tendons.

2. A frame composed of steel-concrete composite columns and prestressed steel-concrete composite beams as described in claim 1, characterized in that, The beam reinforcement cage includes bottom reinforcement, web reinforcement, top reinforcement, and several stirrups along the axial direction of the steel-concrete beam. The bottom reinforcement, web reinforcement, and top reinforcement are tied to the stirrups. The column reinforcement cage includes longitudinal reinforcement and several stirrups along the axial direction of the steel-concrete column. The longitudinal reinforcement is tied to the stirrups.

3. A frame composed of steel-concrete composite columns and prestressed steel-concrete composite beams as described in claim 2, characterized in that, The beam web reinforcement is fixed by beam tie bars; the beam tie bars are welded to the beam web, or multiple through holes are evenly opened on the beam web along the beam axis, and the beam tie bars pass through the through holes to connect to the beam web reinforcement.

4. A frame composed of steel-concrete composite columns and prestressed steel-concrete composite beams as described in claim 3, characterized in that, Multiple studs are fixed to the upper and lower ends of the beam web, the beam flanges, the sides of the beam web, and the outer side of the column flanges.

5. A frame composed of steel-concrete composite columns and prestressed steel-concrete composite beams as described in claim 4, characterized in that, The beam steel is welded and fixed to the outer side of the column flange plate; the column steel is fixed with reinforcing ribs at the upper and lower elevations of the beam flange plate, and the reinforcing ribs are fixedly connected to the column flange plate and the cross web plate; the beam flange plate is fixed with a steel bar connector for connecting the column longitudinal reinforcement, and a reinforcing plate is provided at the connection of the longitudinal reinforcement.

6. A frame composed of steel-concrete composite columns and prestressed steel-concrete composite beams as described in claim 5, characterized in that, The column flange is welded with a steel bar connector. Some of the top or bottom reinforcement bars of the beam are connected to the column flange through the steel bar connector. Some of the top or bottom reinforcement bars of the beam are directly anchored into the steel-concrete column from both sides of the column flange.

7. A frame composed of steel-concrete composite columns and prestressed steel-concrete composite beams as described in claim 1, characterized in that, When the lateral force resisting frame is a single-span frame, the connection node between the steel-concrete beam and the steel-concrete column is the T-joint point; at the T-joint point, the prestressing tendons are anchored on the side of the steel-concrete column away from the steel-concrete beam; the prestressing tendons are locked after tensioning is completed.

8. A frame composed of steel-concrete composite columns and prestressed steel-concrete composite beams as described in claim 1, characterized in that, When the lateral force resisting frame is a multi-span frame, the connection node between the steel-concrete beam and the steel-concrete column is a cross node; the cross node has multiple tensioning slots reserved in the stirrup reinforcement zone of the beam in the adjacent span, and the anchorages at the ends of the prestressing tendons are set in the tensioning slots.

9. A frame composed of steel-concrete composite columns and prestressed steel-concrete composite beams as described in claim 8, characterized in that, Tensioning slots, the same number as the prestressing tendons, are provided on the adjacent span beams of the cross node; the tensioning slots corresponding to the prestressing tendons on different sides are staggered; the tensioning slots corresponding to the lower row of prestressing tendons on the same side are set away from the steel-concrete composite column, and the tensioning slots corresponding to the upper row of prestressing tendons on the same side are set close to the steel-concrete composite column.

10. A construction method for a frame composed of steel-concrete composite columns and prestressed steel-concrete composite beams as described in any one of claims 1-9, characterized in that, The specific steps are as follows: Prepare column steel and beam steel in advance; while installing column steel, tie column longitudinal reinforcement and column stirrups, reserve connection nodes with steel-concrete beams, and support and pour steel-concrete columns. Once the steel-concrete composite column reaches the required strength, the bottom formwork of the beam is erected, and the beam bottom elevation is adjusted by cambering the middle section of the beam. The beam steel is then installed, the steel reinforcement cage of the steel-concrete composite beam is tied, and the beam steel, the steel reinforcement cage of the steel-concrete composite beam, and the column steel are connected. Position and fix the prestressing tendons, pass them through the column steel connecting anchors, and fix the anchors at the same time; erect the node end formwork and the side formwork of the steel-concrete beam, and pour the steel-concrete beam concrete; Once the concrete strength of the steel-concrete beam reaches the required level, the end formwork of the joint and the side formwork of the steel-concrete beam are removed. After the prestressing tendons are tensioned to the required level, the prestressing tendons are locked and anchored.

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