A partially encased steel reinforced concrete folded beam construction

Abstract

The application discloses a concrete folded beam structure with partially built-in steel bones, which comprises a concrete folded beam composed of a high horizontal beam segment, a vertical beam segment and a low horizontal beam segment, and supports respectively arranged at two ends of the concrete folded beam, the high horizontal beam segment is internally provided with a high horizontal beam segment steel bone arranged along an axial direction of the high horizontal beam segment, the vertical beam segment is internally provided with a vertical beam segment steel bone, the low horizontal beam segment is internally provided with a low horizontal beam segment steel bone arranged along an axial direction of the low horizontal beam segment, the high horizontal beam segment steel bone, the vertical beam segment steel bone and the low horizontal beam segment steel bone are connected in a head-to-tail mode, the sum of axial lengths of the high horizontal beam segment steel bone and the low horizontal beam segment steel bone is shorter than the sum of axial lengths of the high horizontal beam segment and the low horizontal beam segment, and a steel mesh with an overall folded shape is arranged outside the high horizontal beam segment steel bone, the vertical beam segment steel bone and the low horizontal beam segment steel bone, and two ends of the folded steel mesh are respectively connected with corresponding supports. The application aims to balance structural performance and economic benefits by optimizing steel bone configuration and reinforcement design, and can be widely applied in the field of building beam column structures.

Description

Technical Field

[0001] This invention relates to building beam and column structures, and in particular to a concrete folded beam structure with partially built-in steel reinforcement. Background Technology

[0002] With social progress and rising living standards, architectural designs are becoming increasingly complex, and the utilization of interior spaces is becoming more diversified, placing higher demands on structural design. This is especially true in public building design, where column-free large spaces and variations in floor levels are becoming more common, negatively impacting structural layout. Therefore, in structural design, we utilize large-span steel-reinforced concrete folded beams to adapt to changes in building elevation and meet the needs of column-free large spaces. In reinforced concrete structures, vertical folded beams, as structural components with a zigzag shape in the vertical plane, are commonly found in scenarios requiring adaptation to complex architectural forms, spatial functions, or load-bearing requirements. When modern architecture pursues curved or zigzag appearances, vertical folded beams can conform to irregular facades, balancing aesthetics and structural function. In staggered or stepped floor designs, folded beams form continuous supports at different elevations, coordinating the overall structural integrity. Their advantages lie in their flexible matching of irregular building plans or facades, reducing structural height occupation, and increasing headroom.

[0003] The technical problem this invention aims to solve is the configuration of steel reinforcement and reinforcing bars in reinforced concrete vertical folded beams. The stress distribution at the bends of vertical folded beams is complex, involving bending moment, axial force, and shear force under gravity loads and lateral forces. When the bend angle is large, stress concentration is significant, easily leading to concrete cracking. The stress at the bend connection is similar to that of a beam-column joint; under strong earthquakes, plastic hinges easily form at the bend, exacerbating the unfavorable stress conditions. The reinforcing bars within the folded beam need to be bent multiple times or anchored to each other according to the bend angle, which weakens the reliability of the reinforcement connections. For folded beams with small bend angles and small spans, the redundancy can be increased by increasing the reinforcement area; for folded beams with large bend angles or large spans, it is usually advisable to add steel reinforcement within the beam, using continuous steel reinforcement to bear the complex stress state at the bend.

[0004] This is mainly because, when traditional reinforced concrete folded beams bear vertical loads, the corner area is prone to stress concentration due to sudden changes in bending moment, leading to concrete cracking and main reinforcement yielding, thereby reducing the ductility and load-bearing capacity of the structure. Especially in large-span or high-intensity seismic fortification areas, ordinary reinforcement schemes are difficult to meet the shear and torsional resistance requirements of the folded beam joint area. Domestic and foreign scholars have found through experiments that the crack development pattern at the corner of the folded beam is radially distributed, and the crack width is negatively correlated with the radius of curvature of the corner, urgently requiring innovative structural measures to improve its stress performance. The introduction of steel-reinforced concrete structures provides a new approach to improve the load-bearing efficiency of folded beams. According to the "Code for Design of Composite Structures", the built-in steel frame can significantly enhance the bending stiffness of the member and delay the propagation of concrete cracks. Its core advantage lies in the material complementarity of steel and concrete: the steel frame bears the peak tensile and compressive stresses, while the outer concrete inhibits the local buckling of the steel frame.

[0005] The existing technical solution involves embedding steel reinforcement along the entire length of the vertical reinforced concrete beam. The disadvantages of this approach are significant material waste, especially when the beam span is large and the bending moment at mid-span or one support is relatively small. Furthermore, embedding steel reinforcement along the entire length complicates the beam-column joint, requiring additional internal steel reinforcement within the column for connection, thus increasing construction difficulty.

[0006] In response to this situation, it is necessary to study a large-span folded beam structure with partially built-in steel reinforcement. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a concrete folded beam structure with partially built-in steel reinforcement, which aims to achieve a balance between structural performance and economic benefits through optimized steel reinforcement configuration and reinforcement design.

[0008] This invention provides a partially reinforced concrete folded beam structure, comprising a concrete folded beam composed of a high horizontal beam segment, a vertical beam segment, and a low horizontal beam segment, and supports located at both ends of the concrete folded beam. The high horizontal beam segment contains a high horizontal beam segment steel skeleton arranged along its axial direction, the vertical beam segment contains a vertical beam segment steel skeleton, and the low horizontal beam segment contains a low horizontal beam segment steel skeleton arranged along its axial direction. The high horizontal beam segment steel skeleton, the vertical beam segment steel skeleton, and the low horizontal beam segment steel skeleton are connected end to end. The sum of the axial lengths of the high horizontal beam segment steel skeleton and the low horizontal beam segment steel skeleton is shorter than the sum of the axial lengths of the high horizontal beam segment and the low horizontal beam segment. The outer sides of the high horizontal beam segment steel skeleton, the vertical beam segment steel skeleton, and the low horizontal beam segment steel skeleton are provided with an integrally folded steel mesh, and the two ends of the folded steel mesh are respectively connected to the corresponding supports.

[0009] In the above technical solution, the top and bottom of the high-level beam segment steel frame and the low-level beam segment steel frame, as well as both sides of the vertical beam segment steel frame, are all flange plates. The top flange plate of the high-level beam segment steel frame and the low-level beam segment steel frame are connected to the flange plate on one side of the vertical beam segment steel frame, and the bottom flange plate of the high-level beam segment steel frame and the low-level beam segment steel frame are connected to the flange plate on the other side of the vertical beam segment steel frame. Above the top flange plate of the high-level beam segment steel frame and the low-level beam segment steel frame, multiple upper longitudinal reinforcing bars are evenly distributed within the width of the flange plate along the axial direction of the flange plate. Below the bottom flange plate of the high-level beam segment steel frame and the low-level beam segment steel frame, multiple lower longitudinal reinforcing bars are evenly distributed within the width of the flange plate along the axial direction of the flange plate. The upper longitudinal reinforcing bars within the width of the flange plate of the high-level beam segment steel frame and the lower longitudinal reinforcing bars within the width of the flange plate of the high-level beam segment steel frame and the low-level beam segment steel frame all extend into the vertical beam segment.

[0010] In the above technical solution, an inclined connecting plate is provided at the bottom of the intersection of the high-level beam segment steel and the vertical beam segment steel. The lower longitudinal steel bars within the flange width of the high-level beam segment steel are connected to the inclined connecting plate and extend vertically into the vertical beam segment along the surface of the inclined connecting plate until they bend below the low-level beam segment steel. The lower longitudinal steel bars within the flange width of the low-level beam segment steel are bent and extend into the vertical beam segment. The lower longitudinal steel bars within the flange width of the high-level beam segment steel are welded to the surface of the inclined connecting plate. The connection points between the two ends of the inclined connecting plate and the high-level beam segment steel and the vertical beam segment steel are the high-point connection line and the low-point connection line, respectively. A vertically arranged first stiffening plate is provided in the high-level beam segment steel corresponding to the high-point connection line, and a horizontally arranged second stiffening plate is provided in the vertical beam segment steel corresponding to the low-point connection line.

[0011] In the above technical solution, a cross-shaped orthogonal connecting plate is provided above the intersection of the vertical beam segment steel and the low horizontal beam segment steel. One end of the horizontal plate of the cross-shaped orthogonal connecting plate is connected to the flange plate of the vertical beam segment steel, and one end of the vertical plate of the cross-shaped orthogonal connecting plate is connected to the top flange plate of the low horizontal beam segment steel. The upper longitudinal reinforcement within the width of the flange plate of the high horizontal beam segment steel enters the vertical beam segment and is welded to the vertical plate surface of the cross-shaped orthogonal connecting plate. The upper longitudinal reinforcement within the width of the flange plate of the low horizontal beam segment steel is welded to the horizontal plate surface of the cross-shaped orthogonal connecting plate. A third horizontally arranged stiffening plate is provided in the vertical beam segment steel corresponding to the horizontal plate of the cross-shaped orthogonal connecting plate. A fourth vertically arranged stiffening plate is provided in the low horizontal beam segment steel corresponding to the vertical plate of the cross-shaped orthogonal connecting plate.

[0012] In the above technical solution, longitudinal reinforcing bars beyond the width of the flange plate are provided above the top and below the bottom of the steel skeleton of the high-level beam segment and the steel skeleton of the low-level beam segment, as well as on the oblique outer side of the flange plate of the steel skeleton of the vertical beam segment. The ends of the longitudinal reinforcing bars beyond the width of the flange plate in the high-level beam segment and the low-level beam segment are bent in the direction of extension of the vertical beam segment. The two ends of the longitudinal reinforcing bars beyond the width of the flange plate in the vertical beam segment are bent in the direction of extension of the high-level beam segment and the low-level beam segment, respectively. The high-level beam segment, the vertical beam segment and the low-level beam segment are provided with multiple rings of stirrups arranged according to the axial section of each beam segment. The upper longitudinal reinforcing bars within the width of the flange plate, the lower longitudinal reinforcing bars within the width of the flange plate and the longitudinal reinforcing bars outside the width of the flange plate are all connected to the inner side of the multiple rings of stirrups.

[0013] In the above technical solution, beam side reinforcement is provided between the top and bottom of the high-level beam segment and the low-level beam segment, and between the longitudinal reinforcement outside the width of the flange plate on both sides of the vertical beam segment. The ends of the beam side reinforcement in the high-level beam segment and the low-level beam segment are bent in the direction of extension of the vertical beam segment, and the two ends of the beam side reinforcement in the vertical beam segment are bent in the direction of extension of the high-level beam segment and the low-level beam segment, respectively. The beam side reinforcement is connected to the inner side of the multi-ring stirrup.

[0014] In the above technical solution, the concrete folded beam is provided with multiple oblique additional reinforcing bars. The multiple oblique additional reinforcing bars are arranged from high to low, and their two ends pass through the vertical beam segment and extend into the high horizontal beam segment and the low horizontal beam segment respectively. The multiple oblique additional reinforcing bars are symmetrically arranged along the steel skeleton of the corresponding high horizontal beam segment, the steel skeleton of the vertical beam segment and the steel skeleton of the low horizontal beam segment. More than half of the length of the multiple oblique additional reinforcing bars is located between the longitudinal reinforcing bars outside the width of the corresponding flange plate. The multiple oblique additional reinforcing bars are connected to the inner side of the stirrups they pass through.

[0015] In the above technical solution, a gap is provided between the bottom end of the upper longitudinal steel bar within the flange width of the high-level beam segment steel frame and the end of the upper longitudinal steel bar within the flange width of the low-level beam segment steel frame.

[0016] In the above technical solution, the spacing between the stirrups located at the vertical beam segment steel members and at the connection points between the vertical beam segment steel members and the high-level beam segment steel members, and between the vertical beam segment steel members and the low-level beam segment steel members in the concrete folded beam is less than the spacing between the stirrups located at the beam segments other than the vertical beam segment steel members and at the connection points between the vertical beam segment steel members and the high-level beam segment steel members, and between the vertical beam segment steel members and the low-level beam segment steel members in the concrete folded beam.

[0017] In the above technical solution, the axial length of the steel reinforcement in the low-level beam segment is equal to or less than the axial length of the low-level beam segment, or the steel reinforcement in the low-level beam segment extends into the corresponding support along the low-level beam segment; the bending length of the longitudinal reinforcement outside the flange width and the side reinforcement of the beam is not less than 15 times the diameter of the reinforcement; the inclined connecting plate and the inclined additional reinforcement are both at a 45° angle to the horizontal plane; the stirrups are two-legged or four-legged stirrups; when the stirrups are four-legged stirrups, the longitudinal reinforcement outside the flange width, the side reinforcement of the beam, and the inclined additional reinforcement are all connected to the outer stirrups; when the stirrups are two-legged stirrups, the diameter of the two-legged stirrups is greater than the diameter of the four-legged stirrups; the longitudinal reinforcement outside the flange width in the high-level beam segment and The side reinforcement of the beam is connected to or extends into the corresponding support sidewall; when the end of the steel reinforcement of the lower horizontal beam segment is connected to the corresponding support sidewall, the longitudinal reinforcement outside the flange width and the side reinforcement of the beam in the lower horizontal beam segment are connected to the reinforcement of the corresponding support sidewall; when the steel reinforcement of the lower horizontal beam segment extends into the corresponding support along the lower horizontal beam segment, the longitudinal reinforcement and the side reinforcement of the beam in the lower horizontal beam segment extend into the corresponding support; the multiple rings of stirrups in the concrete folded beam located at the steel reinforcement of the vertical beam segment and at the connection between the steel reinforcement of the vertical beam segment and the steel reinforcement of the higher horizontal beam segment, and the steel reinforcement of the vertical beam segment and the steel reinforcement of the lower horizontal beam segment form the first stirrup reinforcement zone, and the connection between the higher horizontal beam segment and the lower horizontal beam segment and the corresponding support is provided with a second stirrup reinforcement zone. The axial length of both the first and second stirrup reinforcement zones is not less than 1.5 times the beam height and not less than 500 mm; there are four diagonal additional reinforcement bars, two on each side of the high-level beam segment steel reinforcement, the vertical beam segment steel reinforcement, and the low-level beam segment steel reinforcement; the total cross-sectional area of ​​the four diagonal additional reinforcement bars is not less than the total cross-sectional area of ​​the upper longitudinal reinforcement bars within the width of the flange plate and the total cross-sectional area of ​​the lower longitudinal reinforcement bars within the width of the flange plate; the diameter of the two upper diagonal additional reinforcement bars is the same as the diameter of the largest longitudinal reinforcement bar among the upper longitudinal reinforcement bars within the width of the flange plate and the longitudinal reinforcement bars outside the width of the flange plate; the diameter of the two lower diagonal additional reinforcement bars is the same as the diameter of the largest longitudinal reinforcement bar among the upper longitudinal reinforcement bars within the width of the flange plate and the longitudinal reinforcement bars outside the width of the flange plate. The diameter of the largest longitudinal steel bar in the lower longitudinal reinforcement and the longitudinal reinforcement outside the flange plate width is the same; the upper longitudinal steel bars within the flange plate width are welded to the cross-shaped orthogonal connecting plate on both sides; the lower longitudinal steel bars within the flange plate width of the high-level beam segment steel are welded to the oblique connecting plate on both sides; the high-level beam segment steel, vertical beam segment steel, and low-level beam segment steel are I-beams or U-shaped steels; when the high-level beam segment steel, vertical beam segment steel, and low-level beam segment steel are U-shaped steels, the top and bottom surfaces of the high-level beam segment steel and the low-level beam segment steel are flange plates, and the sidewall connecting the vertical beam segment steel to the flange plates of the high-level beam segment steel and the low-level beam segment steel is a flange plate.

[0018] The concrete folded beam structure with partially built-in steel reinforcement of the present invention has the following beneficial effects: Segmented steel reinforcement: Based on the characteristics of bending moment distribution, steel reinforcement is only placed in vertical beam segments with complex stress or in the extension area of ​​supports with large bending moments, which significantly reduces the amount of steel used. Simplified node construction: Avoids the complex connection between traditional full-length steel frame and column nodes, reduces the need for pre-embedded steel frames in the column, eliminates the spatial interference problem between steel bars and steel frames, and improves construction convenience. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the external overall structure of the concrete folded beam structure with partially built-in steel reinforcement of the present invention; Figure 2 This is a schematic diagram of the internal structure of the longitudinal steel bars, steel frame, connecting plate and stiffening plate within the width of the flange plate in the concrete folded beam of Embodiment 1 of the present invention, which is a partially built-in steel frame concrete folded beam structure. Figure 3 This is a schematic cross-sectional view of the beam segment outside the first stirrup reinforcement zone in the high-level beam segment of Embodiment 1 of the concrete folded beam structure with partially built-in steel reinforcement of the present invention; Figure 4 This is a schematic diagram of the internal structure of the longitudinal reinforcement outside the flange width, the side reinforcement of the beam, and the diagonal additional reinforcement in the concrete folded beam of Embodiment 1 of the present invention, which is a partially built-in steel frame concrete folded beam structure. Figure 5 This is a cross-sectional schematic diagram of the beam segment in the first stirrup reinforcement zone of the high-level beam segment in Embodiment 1 of the concrete folded beam structure with partially built-in steel reinforcement of the present invention; Figure 6 This is a schematic diagram showing the distribution of dense stirrups in the concrete folded beam of Embodiment 1 of the present invention, which features a partially built-in steel frame. Figure 7 This is a schematic diagram of the low-level beam segment steel skeleton connected to the support sidewall in Embodiment 1 of the concrete folded beam structure with partially built-in steel skeleton of the present invention. Figure 8 This is a schematic diagram of the structure in which the longitudinal reinforcement outside the flange width and the side reinforcement of the beam are connected to the support sidewall in the horizontal beam segment of the concrete folded beam structure embodiment 1 of the present invention with partially built-in steel reinforcement. Figure 9 This is a schematic diagram of the low-level beam segment steel reinforcement entering the corresponding support in Embodiment 2 of the concrete folded beam structure with partially built-in steel reinforcement of the present invention. Figure 10 This is a schematic diagram of the longitudinal reinforcement outside the flange width and the side reinforcement of the beam entering the corresponding support in Embodiment 2 of the concrete folded beam structure with partially built-in steel reinforcement of the present invention, for the horizontal beam segment of the horizontal beam segment. Figure 11 This is a schematic diagram of the cross-section of a high-level beam segment in the first stirrup reinforcement zone of the concrete folded beam structure embodiment 2 of the present invention, where the stirrups are four-legged stirrups. Figure 12 This is a beam bending moment diagram for the concrete folded beam structure with partially built-in steel reinforcement of this invention. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments, but these embodiments should not be construed as limiting the present invention.

[0021] This invention addresses some of the shortcomings of traditional steel-reinforced concrete folded beams, providing a novel large-span concrete folded beam and reinforcement structure with partially built-in steel reinforcement. The aim is to achieve a balance between structural performance and economic benefits through optimized steel reinforcement configuration and design. The folded beam structure comprises concrete beams, steel reinforcement, and longitudinal steel bars.

[0022] See Figure 1 The present invention includes a partially built-in steel frame concrete folded beam structure, comprising a concrete folded beam 1 composed of a high horizontal beam segment 1.1, a vertical beam segment 1.2 and a low horizontal beam segment 1.3, and supports located at both ends of the concrete folded beam 1.

[0023] Example 1 See Figures 2 to 3 The high-level beam segment 1.1 contains a high-level beam segment steel frame 2 arranged along its axial direction, the vertical beam segment 1.2 contains a vertical beam segment steel frame 3, and the low-level beam segment 1.3 contains a low-level beam segment steel frame 4 arranged along its axial direction. The high-level beam segment steel frame 2, the vertical beam segment steel frame 3, and the low-level beam segment steel frame 4 are connected end to end. In one or more embodiments, the high-level beam segment steel frame 2, the vertical beam segment steel frame 3, and the low-level beam segment steel frame 4 are I-beams. The sum of the axial lengths of the high-level beam segment steel frame 2 and the low-level beam segment steel frame 4 is shorter than the sum of the axial lengths of the high-level beam segment 1.1 and the low-level beam segment 1.3. The outer sides of the high-level beam segment steel frame 2, the vertical beam segment steel frame 3, and the low-level beam segment steel frame 4 are provided with an integrally folded steel mesh, and the two ends of the folded steel mesh are respectively connected to the corresponding supports.

[0024] The top and bottom of the high-level beam segment steel rib 2 and the low-level beam segment steel rib 4, as well as both sides of the vertical beam segment steel rib 3, are all flange plates. The top flange plates of the high-level beam segment steel rib 2 and the low-level beam segment steel rib 4 are connected to the flange plate on one side of the vertical beam segment steel rib 3, and the bottom flange plates of the high-level beam segment steel rib 2 and the low-level beam segment steel rib 4 are connected to the flange plate on the other side of the vertical beam segment steel rib 3. The top flange plates of the high-level beam segment steel rib 2 and the low-level beam segment steel rib 4 are evenly distributed above them. There are multiple upper longitudinal reinforcing bars 5 arranged along the axial direction of the flange plate within the width of the flange plate. Below the bottom flange plate of the high horizontal beam segment steel frame 2 and the low horizontal beam segment steel frame 4, there are multiple lower longitudinal reinforcing bars 6 arranged along the axial direction of the flange plate within the width of the flange plate. The upper longitudinal reinforcing bars 5 within the width of the flange plate of the high horizontal beam segment steel frame 2 and the lower longitudinal reinforcing bars 6 within the width of the flange plate of the high horizontal beam segment steel frame 2 and the low horizontal beam segment steel frame 4 all extend into the vertical beam segment 1.2.

[0025] At the bottom of the intersection of the high-level beam segment steel 2 and the vertical beam segment steel 3, an inclined connecting plate 12 is provided. In one or more embodiments, the inclined connecting plate 12 forms a 45° angle with the horizontal plane. The lower longitudinal steel bars 6 within the flange width of the high-level beam segment steel 2 are connected to the inclined connecting plate 12 and extend vertically along the surface of the inclined connecting plate 12 into the vertical beam segment 1.2 until they reach below the low-level beam segment steel 4 and bend. The lower longitudinal steel bars 6 within the flange width of the low-level beam segment steel 4 are bent and extend into the vertical beam segment 1.2. In beam segment 1.2, the lower longitudinal reinforcing bars 6 within the flange width of the high horizontal beam segment steel frame 2 are welded to the surface of the inclined connecting plate 12. The connection points between the two ends of the inclined connecting plate 12 and the high horizontal beam segment steel frame 2 and the vertical beam segment steel frame 3 are the high connection line 14 and the low connection line 15, respectively. A first vertically arranged stiffening plate 13 is provided in the high horizontal beam segment steel frame 2 at the position corresponding to the high connection line 14, and a second horizontally arranged stiffening plate 13 is provided in the vertical beam segment steel frame 3 at the position corresponding to the low connection line 15.

[0026] The concrete folded beam 1 structure consists of a high horizontal beam segment 1.1, a vertical beam segment 1.2, and a low horizontal beam segment 1.3, forming a folded structure. The stress characteristics of the vertical beam segment 1.2 are similar to those of a short column, mainly exhibiting a combined compression-bending stress state. When the vertical beam segment 1.2 is subjected to both vertical loads and lateral forces, its cross-section exhibits a significant shear force distribution. In this concrete folded beam 1 structure, steel reinforcement is only provided at the vertical beam segment 1.2 or at the support where the bending moment value is large (the support refers to the intersection of the folded beam and the columns at both ends of the folded beam), using continuous steel reinforcement to resist the combined stress (bending moment + shear force + axial force) at the turning point of the concrete folded beam 1. A vertical haunch with a width-to-height ratio of 1:1 is provided at the connection between the bottom of the high horizontal beam segment 1.1 and the vertical beam segment 1.2 (vertical haunches are usually located at the ends of beams or supports, increasing the beam height locally to enhance the load-bearing capacity of the structure, i.e., Figure 2 The inclined concrete structure connected to the inclined connecting plate 12 in the middle relieves stress concentration through gradual cross-section changes.

[0027] A cross-shaped orthogonal connecting plate 11 is provided above the intersection of the vertical beam segment steel 3 and the low-level beam segment steel 4. One end of the horizontal plate of the cross-shaped orthogonal connecting plate 11 is connected to the flange plate of the vertical beam segment steel 3, and one end of the vertical plate of the cross-shaped orthogonal connecting plate 11 is connected to the top flange plate of the low-level beam segment steel 4. The upper longitudinal reinforcing bars 5 within the flange plate width of the high-level beam segment steel 2 enter the vertical beam segment 1.2 and are welded to the vertical plate surface of the cross-shaped orthogonal connecting plate 11. The upper longitudinal reinforcing bars 5 within the flange plate width of the low-level beam segment steel 4 are connected to... The horizontal plates of the cross-shaped orthogonal connecting plate 11 are welded together. In one or more embodiments, there is a gap between the bottom end of the upper longitudinal steel bar 5 within the flange width of the high horizontal beam segment steel 2 and the end of the upper longitudinal steel bar 5 within the flange width of the low horizontal beam segment steel 4. A third horizontally arranged stiffening plate 13 is provided in the vertical beam segment steel 3 of the horizontal plate, corresponding to the horizontal plate of the cross-shaped orthogonal connecting plate 11. A fourth vertically arranged stiffening plate 13 is provided in the low horizontal beam segment steel 4, corresponding to the vertical plate of the cross-shaped orthogonal connecting plate 11.

[0028] In the reinforcement structure of the concrete folded beam 1, the longitudinal reinforcement is divided into two parts: one within the width of the steel flange plate and the other outside the width of the steel flange plate. Anchoring of the longitudinal reinforcement at the bends within the width of the steel flange plate is difficult (this is because the bending space available for the longitudinal reinforcement within the width of the steel flange plate is small, and the concrete may not be able to effectively fix the reinforcement, leading to easy detachment under stress). To avoid the increased construction difficulty caused by multiple bends of the reinforcement, connecting plates are installed at the junctions of vertical beam segment 1.2 with high-level beam segment 1.1 and low-level beam segment 1.3, respectively. The longitudinal reinforcement is welded to the connecting plates for anchorage connection. Among them, the upper longitudinal steel bars 5 within the width of the flange plate are connected to the vertical beam segment 1.2 at the intersection of the top of the low horizontal beam segment 1.3 and the vertical beam segment 1.2 by two orthogonal steel plates, namely the cross orthogonal connecting plates 11. The lower longitudinal steel bars 6 within the width of the flange plate are anchored to the vertical beam segment 1.2 at the intersection of the bottom of the high horizontal beam segment 1.1 and the vertical beam segment 1.2 by 45° oblique connecting plates 12 to avoid construction defects caused by multiple bends. In order to enhance the structural strength, stiffening plates 13 are provided on the opposite side of the flange plate at the corresponding positions of the cross orthogonal connecting plates 11 and the oblique connecting plates 12. The stiffening plates 13 have the same thickness as the corresponding cross orthogonal connecting plates 11 and oblique connecting plates 12 but are not connected.

[0029] See Figures 3 to 4 The high-level beam segment steel frame 2 and the low-level beam segment steel frame 4 are provided with longitudinal steel bars 7 outside the width of the flange plate above the top and below the bottom, as well as on the oblique outer side of the flange plate of the vertical beam segment steel frame 3. The ends of the longitudinal steel bars 7 outside the width of the flange plate in the high-level beam segment 1.1 and the low-level beam segment 1.3 are bent towards the extension direction of the vertical beam segment 1.2. The two ends of the longitudinal steel bars 7 outside the width of the flange plate in the vertical beam segment 1.2 are bent towards the extension directions of the high-level beam segment 1.1 and the low-level beam segment 1.3, respectively. The high-level beam segment 1.1, the vertical beam segment 1.2 and the low-level beam segment 1.3 are provided with multiple rings of stirrups 9 arranged according to the axial section of each beam segment. In one or more embodiments, the stirrups 9 are two-legged stirrups, and the diameter of the two-legged stirrups is larger than that of the four-legged stirrups. The upper longitudinal steel bars 5 within the width of the flange plate, the lower longitudinal steel bars 6 within the width of the flange plate and the longitudinal steel bars 7 outside the width of the flange plate are all connected to the inner side of the multiple rings of stirrups 9.

[0030] Beam side reinforcement bars 8 are provided between the top and bottom of the high horizontal beam segment 1.1 and the low horizontal beam segment 1.3, and between the longitudinal reinforcement bars 7 outside the width of the flange plates on both sides of the vertical beam segment 1.2. The ends of the beam side reinforcement bars 8 in the high horizontal beam segment 1.1 and the low horizontal beam segment 1.3 are bent towards the extension direction of the vertical beam segment 1.2. The two ends of the beam side reinforcement bars 8 in the vertical beam segment 1.2 are bent towards the extension direction of the high horizontal beam segment 1.1 and the low horizontal beam segment 1.3, respectively. All beam side reinforcement bars 8 are connected to the inner side of the multi-ring stirrups 9.

[0031] The concrete folded beam 1 is provided with multiple diagonal additional reinforcing bars 10. In one or more embodiments, the diagonal additional reinforcing bars 10 form a 45° angle with the horizontal plane. There are four diagonal additional reinforcing bars 10 in total, two on each side of the high-level beam segment steel frame 2, the vertical beam segment steel frame 3, and the low-level beam segment steel frame 4. The multiple diagonal additional reinforcing bars 10 are arranged from high to low, and their two ends pass through the vertical beam segment 1.2 and extend into the high-level beam segment 1.1 and the low-level beam segment 1.3 respectively. The multiple diagonal additional reinforcing bars 10 are symmetrically arranged along the sides of the corresponding high-level beam segment steel frame 2, vertical beam segment steel frame 3, and low-level beam segment steel frame 4. See [reference needed]. Figure 5 More than half of the length of the multiple diagonal additional reinforcing bars 10 is located between the longitudinal reinforcing bars 7 outside the width of the corresponding flange plate, and the multiple diagonal additional reinforcing bars 10 are connected to the inner side of the passing stirrups 9.

[0032] In the concrete folded beam 1, the longitudinal reinforcement outside the width of the steel flange plate extends from the high-level beam segment 1.1 and the low-level beam segment 1.3 to the vertical beam segment 1.2, where it is bent and anchored. The longitudinal reinforcement in the vertical beam segment 1.2, namely the longitudinal steel bars 7 and the side reinforcement 8, extends from the high-level beam segment 1.1 and the low-level beam segment 1.3 respectively, forming a closed force transmission path. The bending length at the ends of the longitudinal steel bars 7 and the side reinforcement 8 is not less than 15 times the steel bar diameter. To compensate for the strength loss of the longitudinal reinforcement, additional inclined reinforcement 10 is added on both sides of the high-level beam segment 1.1, the vertical beam segment 1.2, and the low-level beam segment 1.3. The total cross-sectional area of ​​these reinforcements is not less than the total cross-sectional area of ​​the upper longitudinal reinforcement 5 and the lower longitudinal reinforcement 6 within the width of the steel flange plate, forming an additional 45° section. The longitudinal reinforcement 7, the side reinforcement 8, and the diagonal additional reinforcement 10 outside the width of the flange plate are not connected to the steel frame.

[0033] See Figure 6 The spacing between the stirrups 9 located at the vertical beam segment steel 3 and at the connection points between the vertical beam segment steel 3 and the high-level beam segment steel 2, and between the vertical beam segment steel 3 and the low-level beam segment steel 4 in the concrete folded beam 1 is less than the spacing between the stirrups 9 located at the beam segments other than the connection points between the vertical beam segment steel 3 and the high-level beam segment steel 2, and between the vertical beam segment steel 3 and the low-level beam segment steel 4 in the concrete folded beam 1. In one or more embodiments, the multiple rings of stirrups 9 located at the vertical beam segment steel 3 and at the connection points between the vertical beam segment steel 3 and the high-level beam segment steel 2, and between the vertical beam segment steel 3 and the low-level beam segment steel 4 in the concrete folded beam 1 form a first stirrup reinforcement zone 16. A second stirrup reinforcement zone 17 is provided at the connection points between the high-level beam segment 1.1 and the low-level beam segment 1.3 and the corresponding supports. The axial length of both the first stirrup reinforcement zone 16 and the second stirrup reinforcement zone 17 is not less than 1.5 times the beam height and not less than 500 mm.

[0034] See Figures 7 to 8In one or more embodiments, the axial length of the low-level beam segment steel 4 is equal to or less than the axial length of the low-level beam segment 1.3; the longitudinal steel bars 7 and the beam side reinforcement 8 outside the flange width in the high-level beam segment 1.1 are connected to the corresponding support sidewalls. When the end of the low-level beam segment steel 4 is connected to the corresponding support sidewall, the longitudinal steel bars 7 and the beam side reinforcement 8 outside the flange width in the low-level beam segment 1.3 are connected to the corresponding support sidewall reinforcement.

[0035] Example 2 This embodiment is basically the same as Embodiment 1, except that: See Figure 9 The steel reinforcement 4 of the low-level beam segment extends along the low-level beam segment 1.3 into the corresponding support, see [reference]. Figure 10 In the low-level beam segment 1.3, the longitudinal steel bars 7 and the side reinforcement bars 8 outside the flange width extend into the corresponding supports, and in the high-level beam segment 1.1, the longitudinal steel bars 7 and the side reinforcement bars 8 outside the flange width extend into the corresponding supports.

[0036] Whether the steel reinforcement of the horizontal beam segment in the folded beam structure extends into the support depends on the following two situations: 1. Vertical beam segment 1.2 is close to the mid-span and has a large distance from the support. The bending moment at the mid-span is large, while the bending moment at the support is small. Therefore, the steel reinforcement in both the high-level beam segment 1.1 and the low-level beam segment 1.3 does not extend into the support. (See [reference needed]). Figures 7 to 8 ; 2. When the distance between vertical beam segment 1.2 and the support is small and the support bending moment is large, steel reinforcement is installed along the entire length of both the high-level beam segment 1.1 and the low-level beam segment 1.3 between vertical beam segment 1.2 and the support, with one side of the steel reinforcement extending into the support. See [reference needed]. Figures 9 to 10 .

[0037] The steel reinforcement extension lengths within the high-level beam segment 1.1 and low-level beam segment 1.3 of the concrete folded beam 1 need to be determined based on the beam bending moment diagram, and must encompass the extreme bending moment region. When the positive bending moment at mid-span is large, the steel reinforcement lengths within the high-level beam segment 1.1 and low-level beam segment 1.3 need to encompass the positive bending moment region; when the negative bending moment at the support is large, the steel reinforcement lengths within the high-level beam segment 1.1 and low-level beam segment 1.3 need to encompass the negative bending moment region.

[0038] The bending length of the longitudinal reinforcement 7 and the side reinforcement 8 outside the width of the flange plate shall not be less than 15 times the diameter of the reinforcement.

[0039] See Figure 11 When the difference between the beam width and the steel flange width is not less than 250mm, the stirrup 9 is a four-legged stirrup; when the stirrup 9 is a four-legged stirrup, the longitudinal steel bar 7 outside the flange width, the beam side waist bar 8 and the diagonal additional steel bar 10 are all connected to the outer stirrup 9.

[0040] The total cross-sectional area of ​​the four oblique additional reinforcing bars 10 is not less than the total cross-sectional area of ​​the upper longitudinal reinforcing bars 5 within the width of the flange plates and the total cross-sectional area of ​​the lower longitudinal reinforcing bars 6 within the width of the flange plates; the diameter of the two upper oblique additional reinforcing bars 10 is the same as the diameter of the largest reinforcing bar among the upper longitudinal reinforcing bars 5 within the width of the flange plates and the longitudinal reinforcing bars 7 outside the width of the flange plates; the diameter of the two lower oblique additional reinforcing bars 10 is the same as the diameter of the largest reinforcing bar among the lower longitudinal reinforcing bars 6 within the width of the flange plates and the longitudinal reinforcing bars 7 outside the width of the flange plates.

[0041] The upper longitudinal steel bar 5 within the width of the flange plate is welded to the cross orthogonal connecting plate 11 on both sides, and the lower longitudinal steel bar 6 within the width of the flange plate of the high horizontal beam segment steel frame 2 is welded to the oblique connecting plate 12 on both sides.

[0042] The high-level beam segment steel rib 2, the vertical beam segment steel rib 3, and the low-level beam segment steel rib 4 are U-shaped steel ribs. The top and bottom surfaces of the high-level beam segment steel rib 2 and the low-level beam segment steel rib 4 are flange plates, and the side wall of the vertical beam segment steel rib 3 that connects to the flange plates of the high-level beam segment steel rib 2 and the low-level beam segment steel rib 4 is a flange plate.

[0043] The stirrups 9 of the concrete folded beam 1 are constructed in the non-steel-reinforced sections in the same manner as ordinary horizontal beams, with a second stirrup reinforcement zone 17 at the supports, extending at least 1.5 times the beam height and at least 500 mm in length. Unlike ordinary beams, the steel-reinforced folded beam also requires stirrup reinforcement zones at the mid-span (i.e., at the vertical beam segment steel 3) and at the connections between the vertical beam segment steel 3 and the higher horizontal beam segment steel 2, and between the vertical beam segment steel 3 and the lower horizontal beam segment steel 4. A first stirrup reinforcement zone 16 extends from the turning point of the vertical beam segment steel 3 towards the support, extending at least 1.5 times the beam height and at least 500 mm in length. If necessary, the stirrups 9 of the steel-reinforced beam segments must be reinforced along their entire length. When the difference between the width of the steel flange and the width of the concrete folded beam 1 section is small, resulting in the inability to increase the number of stirrup legs 9, the diameter of stirrup 9 can be increased to ensure that the area of ​​stirrup 9 meets the requirements of the reinforced zone (in the example, based on the calculation results and the minimum stirrup ratio, it is necessary to set two-legged stirrups with a cross-sectional area of ​​not less than 8@100(4), and 12@100(2) was finally selected. When promoting its application, it is only necessary to meet the calculated reinforcement cross-sectional area). See also Figure 11 Normally, when the beam width exceeds 400mm, four-limb stirrups are required. In the embodiment, the 500mm wide concrete folded beam 1 has a 300mm wide steel skeleton. Setting four-limb stirrups would make the distance between the limbs of the stirrups 9 too small, making construction difficult. Therefore, it is necessary to increase the diameter of the stirrups 9 (from 8mm to 12mm) and set them as two-limb stirrups.

[0044] This invention employs a partially internally reinforced concrete folded beam structure. This concrete folded beam structure includes a concrete folded beam 1, a high-level beam segment steel frame 2, a vertical beam segment steel frame 3, and a low-level beam segment steel frame 4, upper longitudinal reinforcement 5 within the flange width, lower longitudinal reinforcement 6 within the flange width, longitudinal reinforcement 7 outside the flange width, beam side reinforcement 8, stirrups 9, diagonal additional reinforcement 10, orthogonal cross-connecting plate 11, diagonal connecting plate 12, and stiffening plate 13. The lengths of the high-level beam segment steel frame 2 and the low-level beam segment steel frame 4 need to be determined and calculated based on the bending moment diagram of the concrete folded beam 1. The upper longitudinal reinforcement 5 within the flange width of the vertical beam segment 1.2 and the upper longitudinal reinforcement 5 within the flange width of the low horizontal beam segment 1.3 are not connected but have gaps, thus being interrupted by the steel reinforcement. To ensure their strength, the upper longitudinal reinforcement 5 within the flange width is welded to the cross-shaped orthogonal connecting plate 11 on both sides. The ends of the cross-shaped orthogonal connecting plate 11 are welded to the vertical beam segment steel reinforcement 3 and the low horizontal beam segment steel reinforcement 4 respectively, and stiffening plates 13 are installed to strengthen the connection. The lower longitudinal reinforcement 6 within the flange width of the high horizontal beam segment steel reinforcement 2 is bent and welded to the oblique connecting plate 12 on both sides. The oblique connecting plate 12 is welded to the high horizontal beam segment steel reinforcement 2 and the vertical beam segment steel reinforcement 3 respectively, and stiffening plates 13 are installed to strengthen the connection. The longitudinal reinforcement 7 outside the flange width and the beam side reinforcement 8 are connected according to... Figure 10 Bend and anchor. If necessary, reinforced stirrups 9 should be densified along the entire length of the steel-reinforced beam segment. Diagonal additional reinforcement 10 should be provided on both sides of the concrete folded beam 1, as follows: Figure 5 As shown. The diameter of the upper diagonal additional reinforcement 10 is the same as the largest diameter of the upper longitudinal reinforcement 5 within the flange width and the longitudinal reinforcement 7 outside the flange width. The diameter of the lower diagonal additional reinforcement 10 is the same as the largest diameter of the lower longitudinal reinforcement 6 within the flange width and the longitudinal reinforcement 7 outside the flange width. Furthermore, the total cross-sectional area of ​​the diagonal additional reinforcement 10 must be greater than the total cross-sectional area of ​​both the upper longitudinal reinforcement 5 within the flange width and the lower longitudinal reinforcement 6 within the flange width. This forms a safe and reliable steel fracture beam structure, suitable for large-span vertical fracture beams. This steel fracture beam structure reduces material waste, simplifies beam-column joints, and improves the utilization rate of structural components.

[0045] The technical principles and key points of this invention are as follows: 1. This invention discloses for the first time a concrete vertical folded beam scheme with partially built-in steel reinforcement. The key is that steel reinforcement is only set in the complex stress transition section, while the remaining beam sections are only normally reinforced, which can achieve the purpose of saving materials and simplifying beam-column joints.

[0046] 2. For the bending section of the beam with built-in steel frame, the present invention discloses comprehensive and specific reinforcement measures: vertical haunches, setting connecting plates for steel bar connection, setting diagonal additional steel bars 10 and stirrups 9 for reinforcement.

[0047] 3. Based on the flexible selection of values ​​from the beam bending moment diagram, this invention proposes a basis for determining the length of the built-in steel frame.

[0048] The closest technology to this invention is a concrete vertical folded beam structure with full-length built-in steel reinforcement. Compared to this technology, this invention uses less steel to meet load-bearing requirements, saving materials and increasing the utilization rate of structural components. Installing steel reinforcement along the entire length of the beam segment complicates the beam-column joints; this invention avoids or reduces the need for additional steel reinforcement within the columns, simplifying the beam-column joints and reducing construction difficulty. Furthermore, this invention incorporates comprehensive reinforcement measures at the turning beam segments, including vertical haunches, connecting plates for reinforcing bars, additional diagonal reinforcing bars 10, and denser stirrups 9, making the structure safer and more reliable.

[0049] The feasibility of this invention has been proven through structural calculation software. In the commonly used structural calculation software Yingjianke, a large-span vertical folded beam structure model with a single-span internal steel frame was established, and the beam bending moment diagram was calculated. (See attached diagram.) Figure 12 Analysis of the bending moment diagram shows that the bending moment at the support is relatively small, while the bending moment at the mid-span transition section is relatively large. Therefore, steel reinforcement is only needed at the mid-span transition section. In this embodiment, during the structural construction drawing stage of a museum, a concrete vertical folded beam with partially built-in steel reinforcement, as described in this scheme, was used as the roof frame beam for a column-free large space under a roof with varying elevations. This beam has a span of 19m and a vertical transition section height of 1.5m to 3.6m.

[0050] The advantages of the partially reinforced concrete folded beam structure of this invention are as follows: Segmented steel reinforcement: Based on the characteristics of bending moment distribution, steel reinforcement is only placed in the vertical beam segment 1.2 with complex stress or in the support extension area with large bending moment, which significantly reduces the amount of steel used; Simplified node construction: Avoids the complex connection between traditional full-length steel frame and column nodes, reduces the need for pre-embedded steel frames in the column, eliminates the spatial interference problem between steel bars and steel frames, and improves construction convenience.

[0051] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

[0052] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

Claims

1. A partially reinforced concrete folded beam structure, comprising a concrete folded beam (1) composed of a high horizontal beam segment (1.1), a vertical beam segment (1.2), and a low horizontal beam segment (1.3), and supports located at both ends of the concrete folded beam (1), wherein the high horizontal beam segment (1.1) has a built-in high horizontal beam segment steel frame (2) arranged along its axial direction, the vertical beam segment (1.2) has a built-in vertical beam segment steel frame (3), and the low horizontal beam segment (1.3) has a built-in low horizontal beam segment steel frame (4) arranged along its axial direction, the high horizontal beam segment steel frame (2), the vertical beam segment steel frame (3), and the low horizontal beam segment steel frame (4) are connected end to end, characterized in that: The sum of the axial lengths of the high-level beam segment steel (2) and the low-level beam segment steel (4) is shorter than the sum of the axial lengths of the high-level beam segment (1.1) and the low-level beam segment (1.3). The high-level beam segment steel (2), the vertical beam segment steel (3) and the low-level beam segment steel (4) are provided with an integral folded steel mesh on their outer sides. The two ends of the folded steel mesh are respectively connected to the corresponding supports.

2. The concrete folded beam structure with partially built-in steel reinforcement according to claim 1, characterized in that: The top and bottom of the high-level beam segment steel frame (2) and the low-level beam segment steel frame (4), as well as both sides of the vertical beam segment steel frame (3), are all flange plates. The top flange plates of the high-level beam segment steel frame (2) and the low-level beam segment steel frame (4) are connected to the flange plate on one side of the vertical beam segment steel frame (3), and the bottom flange plates of the high-level beam segment steel frame (2) and the low-level beam segment steel frame (4) are connected to the flange plate on the other side of the vertical beam segment steel frame (3). Above the top flange plates of the high-level beam segment steel frame (2) and the low-level beam segment steel frame (4) are all Multiple upper longitudinal reinforcing bars (5) are arranged along the axial direction of the flange plate within the width of the flange plate. Multiple lower longitudinal reinforcing bars (6) are evenly distributed below the bottom flange plate of the high horizontal beam segment steel skeleton (2) and the low horizontal beam segment steel skeleton (4). The upper longitudinal reinforcing bars (5) within the flange plate width of the high horizontal beam segment steel skeleton (2) and the lower longitudinal reinforcing bars (6) within the flange plate width of the high horizontal beam segment steel skeleton (2) and the low horizontal beam segment steel skeleton (4) all extend into the vertical beam segment (1.2).

3. The concrete folded beam structure with partially built-in steel reinforcement according to claim 2, characterized in that: At the bottom of the intersection of the high-level beam segment steel (2) and the vertical beam segment steel (3), there is an inclined connecting plate (12). The lower longitudinal steel bars (6) within the flange width of the high-level beam segment steel (2) are connected to the inclined connecting plate (12) and extend vertically into the vertical beam segment (1.2) along the surface of the inclined connecting plate (12) until they reach below the low-level beam segment steel (4) and bend. The lower longitudinal steel bars (6) within the flange width of the low-level beam segment steel (4) are bent and extend into the vertical beam segment (1.2). The high-level beam segment steel (2) The lower longitudinal steel bars (6) within the width of the flange plate are welded to the surface of the inclined connecting plate (12). The connection points of the two ends of the inclined connecting plate (12) with the high horizontal beam segment steel skeleton (2) and the vertical beam segment steel skeleton (3) are the high connection line (14) and the low connection line (15), respectively. The high horizontal beam segment steel skeleton (2) is provided with a vertically set first stiffening plate (13) corresponding to the high connection line (14), and the vertical beam segment steel skeleton (3) is provided with a horizontally set second stiffening plate (13) corresponding to the low connection line (15).

4. The concrete folded beam structure with partially built-in steel reinforcement according to claim 3, characterized in that: A cross-shaped orthogonal connecting plate (11) is provided above the intersection of the vertical beam segment steel (3) and the low horizontal beam segment steel (4). One end of the horizontal plate of the cross-shaped orthogonal connecting plate (11) is connected to the flange plate of the vertical beam segment steel (3), and one end of the vertical plate of the cross-shaped orthogonal connecting plate (11) is connected to the flange plate at the top of the low horizontal beam segment steel (4). The upper longitudinal reinforcement (5) within the flange plate width of the high horizontal beam segment steel (2) enters the vertical beam segment (1.2) and connects with the cross-shaped orthogonal connecting plate (11). The vertical plates of the 1) are welded together. The upper longitudinal steel bars (5) within the flange width of the low horizontal beam section steel (4) are welded together with the horizontal plate of the cross orthogonal connecting plate (11). A third stiffening plate (13) is horizontally arranged in the vertical beam section steel (3) corresponding to the horizontal plate of the cross orthogonal connecting plate (11). A fourth stiffening plate (13) is vertically arranged in the low horizontal beam section steel (4) corresponding to the vertical plate of the cross orthogonal connecting plate (11).

5. The concrete folded beam structure with partially built-in steel reinforcement according to claim 4, characterized in that: The high-level beam segment steel frame (2) and the low-level beam segment steel frame (4) are provided with longitudinal steel bars (7) outside the width of the flange plate, both above the top and below the bottom, and on the oblique outer side of the flange plate of the vertical beam segment steel frame (3). The ends of the longitudinal steel bars (7) outside the width of the flange plate in the high-level beam segment (1.1) and the low-level beam segment (1.3) are bent towards the direction of extension of the vertical beam segment (1.2). The longitudinal steel bars (7) outside the width of the flange plate in the vertical beam segment (1.2) are also provided. Both ends are bent towards the high horizontal beam segment (1.1) and the low horizontal beam segment (1.3) respectively. The high horizontal beam segment (1.1), the vertical beam segment (1.2) and the low horizontal beam segment (1.3) are provided with multiple rings of stirrups (9) arranged according to the axial section of each beam segment along their axial direction. The upper longitudinal steel bar (5) within the width of the flange plate, the lower longitudinal steel bar (6) within the width of the flange plate and the longitudinal steel bar (7) outside the width of the flange plate are all connected to the inside of the multiple rings of stirrups (9).

6. The concrete folded beam structure with partially built-in steel reinforcement according to claim 5, characterized in that: Beam side reinforcement bars (8) are provided between the top and bottom of the high horizontal beam segment (1.1) and the low horizontal beam segment (1.3), and between the longitudinal reinforcement bars (7) outside the width of the flange plate on both sides of the vertical beam segment (1.2). The ends of the beam side reinforcement bars (8) in the high horizontal beam segment (1.1) and the low horizontal beam segment (1.3) are bent towards the extension direction of the vertical beam segment (1.2). The two ends of the beam side reinforcement bars (8) in the vertical beam segment (1.2) are bent towards the extension direction of the high horizontal beam segment (1.1) and the low horizontal beam segment (1.3), respectively. The beam side reinforcement bars (8) are all connected to the inside of the multi-ring stirrups (9).

7. The concrete folded beam structure with partially built-in steel reinforcement according to claim 6, characterized in that: The concrete folded beam (1) is provided with multiple oblique additional steel bars (10). The multiple oblique additional steel bars (10) are arranged from high to low, and both ends pass through the vertical beam segment (1.2) and extend into the high horizontal beam segment (1.1) and the low horizontal beam segment (1.3) respectively. The multiple oblique additional steel bars (10) are symmetrically arranged on both sides of the corresponding high horizontal beam segment steel bar (2), vertical beam segment steel bar (3) and low horizontal beam segment steel bar (4). More than half of the length of the multiple oblique additional steel bars (10) is located between the longitudinal steel bars (7) outside the width of the corresponding flange plate. The multiple oblique additional steel bars (10) are connected to the inside of the stirrups (9) they pass through.

8. The concrete folded beam structure with partially built-in steel reinforcement according to claim 7, characterized in that: A gap is provided between the bottom end of the upper longitudinal steel bar (5) within the flange width of the high-level beam segment steel (2) and the end of the upper longitudinal steel bar (5) within the flange width of the low-level beam segment steel (4).

9. The concrete folded beam structure with partially built-in steel reinforcement according to claim 8, characterized in that: The spacing between the stirrups (9) located at the vertical beam segment steel (3) and at the connection between the vertical beam segment steel (3) and the high horizontal beam segment steel (2), and between the vertical beam segment steel (3) and the low horizontal beam segment steel (4) in the concrete folded beam (1) is less than the spacing between the stirrups (9) located at the vertical beam segment steel (3) and at the connection between the vertical beam segment steel (3) and the high horizontal beam segment steel (2), and between the vertical beam segment steel (3) and the low horizontal beam segment steel (4) in the concrete folded beam (1) outside the beam segment.

10. The concrete folded beam structure with partially built-in steel reinforcement according to claim 9, characterized in that: The axial length of the steel reinforcement (4) of the low-level beam segment is equal to or less than the axial length of the low-level beam segment (1.3), or the steel reinforcement (4) of the low-level beam segment extends along the low-level beam segment (1.3) into the corresponding support. The bending length of the longitudinal reinforcement (7) outside the width of the flange plate and the side reinforcement (8) of the beam shall not be less than 15 times the diameter of the reinforcement; The inclined connecting plate (12) and the inclined additional steel bar (10) are both at a 45° angle to the horizontal plane; The stirrup (9) is a two-legged stirrup or a four-legged stirrup; when the stirrup (9) is a four-legged stirrup, the longitudinal steel bars (7) outside the width of the flange plate, the side waist bars (8) of the beam and the diagonal additional steel bars (10) are all connected to the outer stirrup of the stirrup (9); when the stirrup (9) is a two-legged stirrup, the diameter of the two-legged stirrup is larger than the diameter of the four-legged stirrup. The longitudinal steel bars (7) and the side reinforcement bars (8) outside the flange width in the high horizontal beam segment (1.1) are connected to or extend into the corresponding support sidewall; when the end of the steel reinforcement (4) of the low horizontal beam segment is connected to the corresponding support sidewall, the longitudinal steel bars (7) and the side reinforcement bars (8) outside the flange width in the low horizontal beam segment (1.3) are connected to the corresponding support sidewall reinforcement; when the steel reinforcement (4) of the low horizontal beam segment extends into the corresponding support along the low horizontal beam segment (1.3), the longitudinal steel bars (7) and the side reinforcement bars (8) in the low horizontal beam segment (1.3) extend into the corresponding support; The concrete folded beam (1) has multiple rings of stirrups (9) at the vertical beam segment steel skeleton (3) and at the connection between the vertical beam segment steel skeleton (3) and the high horizontal beam segment steel skeleton (2), and the vertical beam segment steel skeleton (3) and the low horizontal beam segment steel skeleton (4) forming a first stirrup reinforcement zone (16). The high horizontal beam segment (1.1) and the low horizontal beam segment (1.3) are provided with a second stirrup reinforcement zone (17) at the connection with the corresponding support. The axial length of the first stirrup reinforcement zone (16) and the second stirrup reinforcement zone (17) is not less than 1.5 times the beam height and not less than 500 mm. There are four diagonal additional reinforcing bars (10), two on each side of the high-level beam segment steel reinforcement (2), the vertical beam segment steel reinforcement (3), and the low-level beam segment steel reinforcement (4); The total cross-sectional area of ​​the four oblique additional reinforcing bars (10) is not less than the total cross-sectional area of ​​the upper longitudinal reinforcing bars (5) within the width of the flange plate and the total cross-sectional area of ​​the lower longitudinal reinforcing bars (6) within the width of the flange plate; the diameter of the two upper oblique additional reinforcing bars (10) is the same as the diameter of the largest reinforcing bar among the upper longitudinal reinforcing bars (5) within the width of the flange plate and the longitudinal reinforcing bars (7) outside the width of the flange plate; the diameter of the two lower oblique additional reinforcing bars (10) is the same as the diameter of the largest reinforcing bar among the lower longitudinal reinforcing bars (6) within the width of the flange plate and the longitudinal reinforcing bars (7) outside the width of the flange plate. The upper longitudinal steel bar (5) within the width of the flange plate is welded to the cross orthogonal connecting plate (11) on both sides, and the lower longitudinal steel bar (6) within the width of the flange plate of the high horizontal beam segment steel skeleton (2) is welded to the oblique connecting plate (12) on both sides. The high-level beam segment steel (2), vertical beam segment steel (3), and low-level beam segment steel (4) are I-beams or U-shaped steel. When the high-level beam segment steel (2), vertical beam segment steel (3), and low-level beam segment steel (4) are U-shaped steel, the top and bottom surfaces of the high-level beam segment steel (2) and low-level beam segment steel (4) are flange plates, and the side wall connecting the vertical beam segment steel (3) with the flange plates of the high-level beam segment steel (2) and low-level beam segment steel (4) is a flange plate.

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