I-shaped UHPC superposed beam

Abstract

The invention discloses an I-shaped UHPC superposed beam. The I-shaped UHPC superposed beam comprises an I-shaped beam and a connecting truss, the connecting truss comprises a first connecting part and a second connecting part which are connected; the first connecting part is provided with a connecting hole used for being connected with an external structure. The second connecting part is arranged in the I-shaped beam; and the I-shaped beam is formed by arranging the second connecting part in a UHPC I-shaped beam template and pouring UHPC. An I-shaped UHPC superposed beam is formed by an I-shaped beam and a connecting truss, a second connecting part of the connecting truss is arranged in a UHPC I-shaped beam template, UHPC is poured to form the I-shaped beam, and the second connecting part is arranged in the I-shaped beam; meanwhile, the I-shaped cross section of the I-shaped beam can give full play to the tensile and shear resistance of UHPC, and the purpose of saving materials is achieved; and dry connection with an external structure is realized through the first connecting part, so that the construction is more convenient, the quality is easier to control, and the construction efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of building structures, in particular to an I-shaped UHPC composite beam. Background Art

[0002] The beam structures used in traditional building structures are mostly ordinary reinforced concrete beams and I-beams. However, ordinary reinforced concrete beams are prone to cracking, require a large amount of concrete and have poor durability, while I-beams have poor fire resistance and corrosion resistance.

[0003] With the continuous development of building materials, ultra-high-performance concrete (UHPC) has become a major building material. UHPC boasts exceptionally high compressive strength (fc > 120 MPa), high tensile strength (ft > 5 MPa), and excellent durability (its chloride ion diffusion coefficient is 1 / 100 that of ordinary concrete). By fabricating UHPC into I-section beams, the tensile and shear resistance of UHPC can be fully utilized.

[0004] However, the existing ultra-high performance concrete beam structure has complex connection structures between nodes and a large amount of wet work, resulting in low construction efficiency. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an I-shaped UHPC composite beam, which enables dry connection between the beam and its nodes, thereby improving construction efficiency.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: An I-shaped UHPC composite beam comprises an I-beam and a connecting truss; the connecting truss comprises a first connecting portion and a second connecting portion connected to each other; the first connecting portion is provided with a connecting hole for connecting to an external structure; the second connecting portion is arranged in the I-beam; the I-beam is formed by arranging the second connecting portion in a UHPC I-beam formwork and casting UHPC.

[0007] The beneficial effects of the present invention are as follows: an I-shaped UHPC composite beam is formed by an I-beam and a connecting truss, and the UHPC is cast into the I-beam by arranging the second connecting portion of the connecting truss in the UHPC I-beam formwork, so that the second connecting portion is built into the I-beam; at the same time, the I-shaped cross-section of the I-beam can give full play to the tensile and shear properties of UHPC and achieve the purpose of saving materials; and a dry connection with the external structure is achieved through the first connecting portion, making construction more convenient and quality easier to control, thereby improving construction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 This is a structural schematic diagram of an I-shaped UHPC composite beam in an embodiment of the present invention; Figure 2 Schematic diagram of a connecting truss structure of an I-shaped UHPC composite beam in an embodiment of the present invention; Figure 3 This is a schematic diagram of the connection of an I-shaped UHPC composite beam in an embodiment of the present invention; Figure 4 This is a schematic diagram of an I-shaped UHPC composite beam assembly according to an embodiment of the present invention; Description of labels: 1. I-beam; 2. Connecting truss; 21. First connection; 211. Vertical plate; 212. Upper flange plate; 213. Lap plate; 22. Second connection; 23. Connection hole; 24. Diamond hole; 25. Stiffener; 3. Longitudinal steel plate; 31. First area; 32. Transition area; 33. Second area; 4. Longitudinal steel bar; 5. Steel cage; 51. Stirrups; 52. Longitudinal steel bar; 6. Connection assembly; 61. Upper flange cover; 62. Lower flange cover; 63. Web cover; 64. Bolt; 65. Concrete cover; 66. Concrete precast slab; 7. H-shaped steel corbel extending from column. DETAILED DESCRIPTION

[0009] To illustrate the technical content, achieved objectives and effects of the present invention in detail, the following description is given in conjunction with the embodiments and accompanying drawings.

[0010] An I-shaped UHPC composite beam comprises an I-beam and a connecting truss; the connecting truss comprises a first connecting portion and a second connecting portion connected to each other; the first connecting portion is provided with a connecting hole for connecting to an external structure; the second connecting portion is arranged in the I-beam; the I-beam is formed by arranging the second connecting portion in a UHPC I-beam formwork and casting UHPC.

[0011] As can be seen from the above description, the beneficial effects of the present invention are as follows: an I-shaped UHPC composite beam is formed by an I-beam and a connecting truss, and the UHPC is cast into the I-beam by arranging the second connecting portion of the connecting truss in the UHPC I-beam formwork, so that the second connecting portion is built into the I-beam; at the same time, the I-shaped cross-section of the I-beam can give full play to the tensile and shear properties of UHPC and achieve the purpose of saving materials; and a dry connection with the external structure is achieved through the first connecting portion, making construction more convenient and quality easier to control, thereby improving construction efficiency.

[0012] Furthermore, the second connecting portion is provided with diamond-shaped holes at equal intervals.

[0013] From the above description, it can be seen that by providing equally spaced diamond holes on the second connection part, that is, the second connection part forms a cross-stitched plate structure, and the cross-stitched plate structure is arranged in the I-beam, the direction of the oblique ties formed by the diamond holes is close to the oblique cracks, which bear the shear force more directly, and its shear resistance efficiency is higher, thereby improving the shear resistance of the composite beam.

[0014] Furthermore, a longitudinal steel plate is provided at the bottom of the connecting truss.

[0015] From the above description, it can be seen that by setting a longitudinal steel plate at the bottom of the connecting truss and coordinating it with a cross-stitched plate structure, a UHPC I-beam with a steel skeleton reinforcement can be formed, thereby improving the tensile performance of the lower flange of the I-shaped UHPC composite beam.

[0016] Furthermore, the longitudinal steel plate includes a first region, a transition region and a second region; the transition region is trapezoidal and is arranged at the junction region between the first connecting portion and the second connecting portion; the width of the first region is greater than the width of the second region.

[0017] It can be seen from the above description that by providing a transition area in the longitudinal steel plate, the problem of stress concentration can be avoided.

[0018] Furthermore, the first connecting part also includes a vertical plate and an upper flange plate; the upper flange plate is arranged on the top of the vertical plate; the upper flange plate and the vertical plate are both provided with the connecting holes; the longitudinal steel plate is provided with the connecting hole at one end close to the first connecting part; the upper flange plate and the longitudinal steel plate are respectively symmetrically arranged with respect to the vertical plate.

[0019] From the above description, it can be seen that by providing connection holes in the vertical plate, the upper flange plate and the longitudinal steel plate, the connection strength between the first connection part and the external structure is increased, thereby improving the stability of the I-shaped UHPC composite beam.

[0020] Furthermore, it also includes a connection component; the connection component includes an upper flange cover plate, a lower flange cover plate and a web cover plate; one end of the upper flange cover plate is connected to the upper flange plate, and the connection hole on the other end is used to connect to an external structure; one end of the lower flange cover plate is connected to the longitudinal steel plate, and the connection hole on the other end is used to connect to an external structure; one end of the web cover plate is connected to the vertical plate, and the connection hole on the other end is used to connect to an external structure.

[0021] From the above description, it can be seen that by using the upper flange cover plate, the lower flange cover plate and the web cover plate as connecting components, the first connecting part is connected to the external structure, so that the first connecting part can form a stable connection with the external structure more quickly.

[0022] Furthermore, the connection assembly also includes a concrete cover and two concrete precast panels; the first connection part also includes a lap plate; the lap plate is arranged between the upper flange plate and the longitudinal steel plate, and the lap plate is symmetrical about the vertical plate; the two concrete precast panels are respectively arranged on the lap plates on both sides of the vertical plate and the upper surface of the I-beam; the concrete cover is formed by pouring concrete between the concrete precast panels.

[0023] From the above description, it can be seen that the use of precast concrete panels as the connection structure not only improves the connection strength between the I-shaped UHPC composite beam and the external structure, but the precast concrete panels can also serve as the formwork for post-poured concrete, thereby greatly reducing the formwork work, reducing on-site wet operations, and improving construction efficiency.

[0024] Furthermore, a stiffening rib is provided between the lap plate and the vertical portion.

[0025] It can be seen from the above description that by providing stiffening ribs between the lap plates and the vertical portions, the punching shear resistance of the I-shaped UHPC composite beam can be improved.

[0026] Furthermore, a steel cage is provided on the top of the second connecting portion; and a side of the steel cage close to the second connecting portion is embedded in the I-beam.

[0027] As can be seen from the above description, by arranging a steel cage on the top of the second connection part and partially burying the steel cage in the I-beam, the interface connection performance between the UHPC I-beam and the concrete composite floor slab can be improved.

[0028] Furthermore, the steel cage includes stirrups and longitudinal steel bars; the stirrups are wound around the longitudinal steel bars and the top of the second connecting portion; and one end of the longitudinal steel bars is connected to the first connecting portion.

[0029] As can be seen from the above description, by forming a steel cage composed of stirrups and longitudinal steel bars, while enhancing the interface connection performance between the UHPC I-beam and the concrete composite floor slab, one end of the longitudinal steel bar is connected to the first connection part, so that the first connection part can transfer the stress of the longitudinal steel bar.

[0030] The I-shaped UHPC composite beam provided by the present invention can be applied to building construction scenarios, and is described below through specific implementation methods: Example 1 Please refer to Figure 1 as well as Figure 2 , an I-shaped UHPC composite beam, comprising an I-beam 1 and a connecting truss 2; Figure 2As shown, the connecting truss 2 is an H-shaped steel connector, comprising a first connecting portion 21 and a second connecting portion 22, i.e., the second connecting portion 22 is the web of the H-shaped steel connector. The first connecting portion 21 is provided with a connection hole 23 for connecting to an external structure. The second connecting portion 22 is disposed within the I-beam 1. The I-beam 1 is formed by placing the second connecting portion 22 within the UHPC I-beam formwork and casting the UHPC. By adopting an I-shaped cross-section design, the flange area of ​​the I-beam 1 maximizes the bearing of bending stress, while the web area concentrates on resisting shear stress, significantly improving cross-sectional efficiency. Compared to traditional rectangular cross-section components, the weight is reduced by 30%-40%, significantly reducing transportation and lifting costs. The cross-sectional moment of inertia is highly adjustable, making it easy to match the load requirements of different spans.

[0031] Please refer to Figure 2 The second connection part 22 of the connecting truss 2 is provided with diamond-shaped holes 24 at equal intervals, so that the second connection part 22 forms a cross-stitch plate; at the same time, a longitudinal steel plate 3 is provided at the bottom of the connecting truss 2; a longitudinal steel bar 4 is provided at the upper edge of the second connection part 22; the longitudinal steel plate 3 and the longitudinal steel bar 4 are connected to the connecting truss 2 by welding, and the connection by welding is easier to realize automation; the UHPC I-beam reinforced by the steel skeleton composed of the longitudinal steel plate 3, the longitudinal steel bar 4 and the cross-stitch plate has better integrity; under the action of shear force, the web of the UHPC I-beam forms multiple oblique cracks, and most of the shear force is borne by the concrete diagonal compression rod. The obliquely arranged cross-stitch plates are in the same direction as the force, which can better exert its shear resistance. Compared with traditional reinforced concrete beams, the reinforced UHPC I-beam is not easy to crack, uses less concrete, is light in weight, and has excellent durability; and it also has good fire resistance and corrosion resistance.

[0032] The longitudinal steel plate 3 includes a first region 31 , a transition region 32 and a second region 33 ; the transition region 32 is trapezoidal and is located at the junction of the first connecting portion 21 and the second connecting portion 22 ; the width of the first region 31 is greater than that of the second region 33 .

[0033] The first connection part 21 also includes a vertical plate 211, an upper flange plate 212 and a lap plate 213; the upper flange plate 212 is arranged on the top of the vertical plate 211; the upper flange plate 212 and the vertical plate 211 are both provided with connection holes 23; the longitudinal steel plate 3 is provided with a connection hole 23 at one end close to the first connection part 21; the upper flange plate 212 and the longitudinal steel plate 3 are respectively symmetrically arranged about the vertical plate 211; wherein, a stiffening rib 25 is provided between the lap plate 213 and the vertical part; the lap plate 213 is arranged at the same height as the first connection part 21 and the upper flange of the I-beam 1 by welding, and is used to overlap the concrete precast plate 66.

[0034] A steel cage 5 is provided on the top of the second connection portion 22; the side of the steel cage 5 close to the second connection portion 22 is embedded in the I-beam 1; wherein the steel cage 5 includes stirrups 51 and longitudinal steel bars 52; stirrups 51 are wound around the longitudinal steel bars 52 and the top of the second connection portion 22; one end of the longitudinal steel bar 52 is connected to the first connection portion 21. Figure 2 As shown, the reinforcement cage 5 is composed of longitudinal reinforcements 52 and stirrups 51 arranged at equal intervals. The stirrups 51 are welded to the longitudinal steel bars 4; and the longitudinal reinforcements 52 are welded to the upper flange plate 212.

[0035] In order to achieve dry connection of the I-shaped UHPC composite beam, in this embodiment, the H-shaped steel connector embedded in the UHPC beam cooperates with the connection assembly 6 to achieve connection with the external structure. The connection between the I-shaped UHPC composite beam and the column extended H-shaped steel bracket 7 is used as an example for description. The connection structure of the column extended H-shaped steel bracket 7 is the same as that of the first connection part 21. The specific connection structure is as follows: Please refer to Figure 3 The connection assembly 6 includes an upper flange cover plate 61, a lower flange cover plate 62 and a web cover plate 63; the connection hole 23 on one end of the upper flange cover plate 61 is connected to the upper flange plate 212, and the connection hole 23 on the other end is connected to the column extended H-shaped steel corbel 7; the connection hole 23 on one end of the lower flange cover plate 62 is connected to the longitudinal steel plate 3, and the connection hole 23 on the other end is used to connect to the column extended H-shaped steel corbel 7; the connection hole 23 on one end of the web cover plate 63 is connected to the vertical plate 211, and the connection hole 23 on the other end is used to connect to the column extended H-shaped steel corbel 7. The connection holes 23 are dry-connected by bolts 64, thereby realizing a dry connection between the I-shaped UHPC composite beam and the column extended H-shaped steel corbel 7 through the connection assembly 6.

[0036] Among them, the connection component 6 also includes a concrete cover 65 and two concrete precast panels 66; the lap plate 213 is arranged between the upper flange plate 212 and the longitudinal steel plate 3, and the lap plate 213 is symmetrical about the vertical plate 211; the two concrete precast panels 66 are respectively arranged on the lap plates 213 on both sides of the vertical plate 211 and the upper surface of the I-beam 1; the concrete cover 65 is formed by pouring concrete between the concrete precast panels 66.

[0037] The construction method of the above-mentioned I-shaped UHPC composite beam is as follows: Please refer to Figure 2Diamond-shaped holes 24 are evenly spaced in the second connection portion 22 of the connecting truss 2 to form a cross-stitch plate. The cross-stitch plate is welded to the longitudinal steel plate 3 and the longitudinal steel bar 4 to form a steel reinforcement frame. A reinforcement cage 5 formed by binding stirrups 51 and longitudinal steel bars 52 is then welded to the top surface of the longitudinal steel bar 4. One end of the longitudinal steel bar 52 is welded to the top surface of the upper flange plate 212 of the first connection portion 21. The bottom of the connecting truss 2 is welded to the longitudinal steel plate 3.

[0038] Please refer to Figure 1 ,After the above components are connected, they are placed in the UHPC I-beam formwork and then cast UHPC to form a stiffened I-shaped UHPC composite beam.

[0039] Please refer to Figure 3 and Figure 4 The first connection 21 of the I-shaped UHPC composite beam is placed parallel to the column's extended H-steel corbel 7, with a 10 mm gap between the two components to prevent damage to the structure from compression and collision during splicing. The first connection 21 is dry-connected to the flange and web of the column's extended H-steel corbel 7 using upper flange caps 61, web caps 63, lower flange caps 62, and bolts 64, respectively.

[0040] After the connection is completed, the two precast concrete panels 66 are overlapped on the overlap plate 213 of the I-shaped UHPC composite beam and the overlap plate 213 of the column extended H-shaped steel corbel 7; then concrete is poured in the joint between the two adjacent precast concrete panels 66, and the construction is completed after the concrete curing requirements are met to form a concrete cover 65.

[0041] Compared with the traditional reinforced concrete beam reinforcement binding process, the modular H-shaped steel frame of "steel plate + cross-stitch plate" used in this embodiment has the following technical advantages: (1) Convenient construction. The standardized frame units are prefabricated in the factory and dry-connected to the structural columns on site through bolts 64, avoiding the reinforcement binding process of cast-in-place concrete beams and improving construction efficiency by more than 50%. (2) Good mechanical properties. In traditional reinforced concrete beams, stirrups 51 are usually placed vertically to resist shear force and constrain longitudinal reinforcement. However, the cross-stitch plate truss I-shaped frame used in this embodiment has better integrity because its steel plates and cross-stitch plates are connected as a whole by welding.

[0042] In summary, the I-shaped UHPC composite beam provided by the present invention is composed of an I-shaped UHPC composite beam through an I-shaped beam and a connecting truss, and the shear and bending resistance of the component is improved by setting the second connection part of the connecting truss as a cross plate and connecting the cross plate with the longitudinal steel plate; and the second connection part is set in the UHPC I-beam template to cast UHPC to form an I-beam, so that the second connection part is built into the I-beam; at the same time, the I-shaped cross section of the I-beam can give full play to the tensile and shear resistance of UHPC and achieve the purpose of saving materials; during the connection construction, the composite plate part of the I-shaped UHPC composite beam adopts a concrete prefabricated plate, which can be used as a template for post-cast concrete, greatly reducing the formwork work and reducing on-site wet work; and when the I-shaped UHPC composite beam is connected to the column, it only needs to be connected to the H-shaped steel bracket extending from the column through high-strength bolts and cover plates. This connection method has reliable quality, simple operation, and low requirements for equipment and personnel.

[0043] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention's description and drawings, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An I-shaped UHPC composite beam, characterized in that: Including I-beams and connecting trusses; The connecting truss comprises a first connecting portion and a second connecting portion that are connected; The first connecting portion is provided with a connecting hole for connecting to an external structure; The second connection portion is arranged in the I-beam; the I-beam is formed by arranging the second connection portion in a UHPC I-beam template and pouring UHPC.

2. The I-shaped UHPC composite beam according to claim 1, characterized in that: The second connecting portion is provided with diamond-shaped holes at equal intervals.

3. The I-shaped UHPC composite beam according to claim 1, characterized in that: A longitudinal steel plate is provided at the bottom of the connecting truss.

4. The I-shaped UHPC composite beam according to claim 3, characterized in that: The longitudinal steel plate includes a first region, a transition region and a second region; The transition area is trapezoidal and is provided at the junction area between the first connecting portion and the second connecting portion; The width of the first region is greater than the width of the second region.

5. The I-shaped UHPC composite beam according to claim 3, characterized in that: The first connecting portion further includes a vertical plate and an upper flange plate; The upper flange plate is arranged on the top of the vertical plate; The upper flange plate and the vertical plate are both provided with the connecting holes; The connecting hole is provided at one end of the longitudinal steel plate close to the first connecting portion; The upper flange plate and the longitudinal steel plate are respectively arranged symmetrically with respect to the vertical plate.

6. The I-shaped UHPC composite beam according to claim 5, characterized in that: Also included are connection components; The connection assembly includes an upper flange cover plate, a lower flange cover plate and a web cover plate; One end of the upper flange cover is connected to the upper flange plate, and a connection hole on the other end is used to connect to an external structure; One end of the lower flange cover is connected to the longitudinal steel plate, and a connection hole on the other end is used to connect to the external structure; One end of the web cover is connected to the vertical plate, and a connection hole on the other end is used for connecting to an external structure.

7. The I-shaped UHPC composite beam according to claim 6, characterized in that: The connection assembly also includes a concrete cover and two precast concrete panels; The first connecting portion further includes a lap plate; The lap plate is arranged between the upper flange plate and the longitudinal steel plate, and the lap plate is symmetrical with respect to the vertical plate; The two precast concrete panels are respectively arranged on the lap plates on both sides of the vertical panel and the upper surface of the I-beam; The concrete cap is formed by pouring concrete between the precast concrete panels.

8. The I-shaped UHPC composite beam according to claim 7, characterized in that: Stiffening ribs are provided between the lap plates and the vertical portions.

9. The I-shaped UHPC composite beam according to claim 1, characterized in that: A steel cage is provided on the top of the second connecting portion; The side of the steel cage close to the second connecting portion is embedded in the I-beam.

10. The I-shaped UHPC composite beam according to claim 9, characterized in that: The reinforcement cage includes stirrups and longitudinal reinforcement; The stirrups are wound around the longitudinal reinforcement and the top of the second connecting portion; One end of the longitudinal steel bar is connected to the first connecting portion.

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