Ultra high performance concrete beam

Abstract

The utility model discloses an ultrahigh performance concrete beam, including UHPC beam body, UHPC beam body includes UHPC beam top plate and the UHPC beam web connected below UHPC beam top plate, and UHPC beam web includes the UHPC horseshoe beam connected below, and UHPC horseshoe beam is provided with a plurality of longitudinal prestressed ducts, and prestressed duct is provided with prestressed reinforcement, and the end of prestressed reinforcement is anchored in the end of UHPC horseshoe beam through prestressed reinforcement anchoring block. The utility model discloses a plurality of longitudinal prestressed ducts are arranged in UHPC horseshoe beam, and then prestressed reinforcement is arranged in longitudinal prestressed duct, so that the prestress of UHPC horseshoe beam is more uniform, reduces the volume of UHPC horseshoe beam body and thereby ensures the light weight of UHPC horseshoe beam, under the premise of guaranteeing satisfying bearing capacity requirement, can make UHPC horseshoe beam bear prestress, and the tensile stress of UHPC beam body is reduced.

Description

Technical Field

[0001] This utility model relates to the field of bridge technology, and in particular to an ultra-high performance concrete beam. Background Technology

[0002] Currently, traditional reinforced or prestressed concrete structures have relatively large self-weights because traditional concrete has low compressive strength. Once cracked, the concrete is no longer usable and is a strain-softening material. Therefore, more concrete, prestressing tendons, and ordinary steel reinforcement are needed to meet the requirements for load-bearing capacity and crack resistance. This results in larger beam cross-sectional dimensions and self-weight, making transportation and installation inconvenient, prone to cracking, and with most of the load-bearing capacity being consumed by its own weight, thus limiting the design flexibility of the components.

[0003] Patent document CN222083322U discloses a thin-web concrete beam with positioning reinforcement, wherein the beam body material is ultra-high performance concrete (UHPC). Although replacing ordinary concrete with UHPC allows for a reduction in the cross-sectional dimensions of the concrete beam body due to the high compressive strength of UHPC, the tensile strength of UHPC is not high. Its design tensile strength is only about 3 MPa higher than that of ordinary concrete. Therefore, if the design tensile stress of the UHPC beam is strictly controlled, further reduction in the self-weight of the concrete beam body is very limited. Utility Model Content

[0004] The purpose of this invention is to provide an ultra-high performance concrete beam, thereby solving the above-mentioned problems.

[0005] To achieve the above objectives, this utility model discloses an ultra-high performance concrete beam, including a UHPC beam body. The UHPC beam body includes a UHPC beam top plate and a UHPC beam web connected below the UHPC beam top plate. The UHPC beam web includes a UHPC horseshoe beam connected below. The UHPC horseshoe beam is provided with multiple longitudinal prestressing ducts, and prestressing tendons are provided in the longitudinal prestressing ducts. The ends of the prestressing tendons are anchored to the ends of the UHPC horseshoe beam through prestressing tendon anchor blocks.

[0006] Furthermore, the prestressing tendons are made of ordinary prestressed steel strands.

[0007] Furthermore, the longitudinal prestressed ducts are arranged in multiple circumferential directions along the cross-section of the UHPC horseshoe beam.

[0008] Furthermore, the UHPC beam is provided with steel fibers, and the prestressing tendons are configured such that the steel fibers harden under tension when the UHPC beam is under tension.

[0009] Furthermore, the web of the UHPC beam is connected to both sides by UHPC web reinforcing ribs, which connect the top plate of the UHPC beam and the UHPC horseshoe beam, and are positioned above the bottom support position of the UHPC beam.

[0010] Furthermore, the web of the UHPC beam is of uniform thickness, and the UHPC horseshoe beam is provided with UHPC horseshoe beam height-increasing sections with gradually increasing height near both ends, and the bottom of the UHPC web reinforcing rib is connected to the UHPC horseshoe beam height-increasing section.

[0011] Furthermore, a top plate steel mesh is provided in the top plate of the UHPC beam, a web steel mesh is provided in the web of the UHPC beam, and a reinforcing rib steel mesh connecting the top plate steel mesh and the web steel mesh is provided in the web reinforcing rib of the UHPC beam.

[0012] Furthermore, the top plate of the UHPC beam is provided with joint ends on both sides for connecting the UHPC beam body, and the reinforcing bars of the top plate steel mesh extend laterally outward from the joint ends.

[0013] Furthermore, a shear groove is provided at the bottom thickened position of the joint end, and a joint groove is provided above the shear groove.

[0014] Furthermore, the top plate and web of the UHPC beam are provided with longitudinal tensile reinforcement bars, which are arranged along the length of the UHPC beam. The UHPC horseshoe beam is surrounded by horseshoe beam stirrups outside the longitudinal tensile reinforcement bars.

[0015] Compared with the prior art, the advantages of this utility model are: This invention provides multiple longitudinal prestressing ducts in the UHPC horseshoe beam, and then installs prestressing tendons in these ducts. This results in more uniform prestressing in the UHPC horseshoe beam, reduces the volume occupied by the UHPC horseshoe beam, and ensures its lightweight design. While ensuring that the load-bearing capacity requirements are met, the UHPC horseshoe beam can bear prestress, reducing the excessive tensile stress in the UHPC beam.

[0016] The present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings: Figure 1 This is a schematic diagram of the overall structure of the ultra-high performance concrete beam disclosed in the embodiment of this utility model.

[0018] Figure 2 This is a schematic diagram of the mid-span section of the ultra-high performance concrete beam disclosed in an embodiment of this utility model.

[0019] Figure 3 This is a left-side schematic diagram of the ultra-high performance concrete beam disclosed in an embodiment of this utility model.

[0020] Legend: 1. Top slab of UHPC beam; 2. Top slab reinforcement mesh; 3. Web reinforcement mesh; 4. Web of UHPC beam; 5. UHPC horseshoe beam; 6. Longitudinal prestressing duct; 7. Longitudinal tensile reinforcement; 8. Prestressing tendon; 9. Horseshoe beam stirrups; 10. Prestressing tendon anchorage block; 11. UHPC web reinforcing rib; 12. UHPC horseshoe beam heightening section; 13. Shear groove; 14. Joint groove; 15. Bottom support position. Detailed Implementation

[0021] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered by the claims.

[0022] like Figure 1-3 As shown, this utility model discloses an ultra-high performance concrete beam, including a UHPC beam body. The UHPC beam body includes a UHPC beam top plate 1 and a UHPC beam web 4 connected below the UHPC beam top plate 1. The UHPC beam web 4 includes a UHPC horseshoe beam 5 connected below. The UHPC material is steel fiber reinforced concrete with a compressive strength of not less than 100MPa. The UHPC horseshoe beam 5 is provided with multiple longitudinal prestressing ducts 6. Prestressing tendons 8 are provided in the longitudinal prestressing ducts 6. The prestressing tendons 8 are ordinary prestressed steel strands, which have lower usage costs. The ends of the prestressing tendons 8 are anchored to the ends of the UHPC horseshoe beam 5 through prestressing tendon anchor blocks 10. This invention provides multiple longitudinal prestressing ducts 6 in the UHPC horseshoe beam 5, and then prestressing tendons 8 in the longitudinal prestressing ducts 6. This makes the prestress of the UHPC horseshoe beam 5 more uniform, without reducing the load-bearing capacity of the UHPC horseshoe beam 5, and reduces the volume occupied by the UHPC horseshoe beam 5, thus ensuring the lightweight of the UHPC horseshoe beam 5. Under the premise of ensuring that the load-bearing capacity requirements are met, the UHPC horseshoe beam 5 can bear prestress, reducing the excessive tensile stress of the UHPC beam body.

[0023] In this embodiment, multiple longitudinal prestressed ducts 6 are arranged circumferentially along the cross-section of the UHPC horseshoe beam 5, specifically four, corresponding diagonally to the UHPC horseshoe beam 5, thereby ensuring that the UHPC horseshoe beam 5 bears more uniform prestress and optimizing the stress situation of the UHPC horseshoe beam 5.

[0024] In this embodiment, the UHPC beam is provided with steel fibers, and the prestressing tendons 8 are configured such that the steel fibers harden under tension when the UHPC beam is under tension. Although the tensile strength of UHPC is not high, it has excellent strain hardening performance. Structurally, this is reflected in the fact that after configuring a small amount of steel reinforcement, the UHPC beam only shows tiny cracks that meet the specifications under high tensile stress (such as 15MPa), thereby maximizing the performance of UHPC and allowing the steel fibers to exert their tensile effect. This can reduce the amount of UHPC material used and achieve further weight reduction.

[0025] In this embodiment, see Figure 1 To improve the shear bearing capacity of the UHPC beam web 4, UHPC web reinforcing ribs 11 are connected to both sides of the UHPC beam web 4. The UHPC web reinforcing ribs 11 connect the UHPC beam top plate 1 and the UHPC horseshoe beam 5, and are positioned above the bottom support position 15 of the UHPC beam. Meanwhile, the UHPC beam web 4 is of uniform thickness, and the UHPC horseshoe beam 5 has gradually increasing height UHPC horseshoe beam extension sections 12 near both ends. The bottom of the UHPC web reinforcing ribs 11 connects to the UHPC horseshoe beam extension sections 12. The UHPC horseshoe beam extension sections 12 improve the shear bearing capacity and also increase the anchorage area at the ends, facilitating the circumferential anchorage installation of multiple prestressed tendon anchor blocks 10.

[0026] In this embodiment, see Figure 2 The top slab 1 of the UHPC beam is provided with a top slab steel mesh 2, the web plate 4 of the UHPC beam is provided with a web plate steel mesh 3, and the web plate reinforcing rib 11 of the UHPC beam is provided with a reinforcing rib steel mesh connecting the top slab steel mesh 2 and the web plate steel mesh 3. The arrangement of the reinforcing rib steel mesh is similar to that of the top slab steel mesh 2 or the web plate steel mesh 3, which further improves the overall strength of the UHPC web plate reinforcing rib 11, the top slab 1 of the UHPC beam, and the web plate 4 of the UHPC beam, and can further reduce the application of UHPC.

[0027] In this embodiment, see Figure 2 To facilitate the splicing of adjacent UHPC beams, joint ends for connecting UHPC beams are provided on both sides of the top slab 1 of the UHPC beam. The reinforcing bars of the top slab steel mesh 2 extend laterally outward from the joint ends, and the connection strength is improved through the connection of adjacent top slab steel meshes 2. At the same time, a shear groove 13 is provided at the thickened position at the bottom of the joint end to improve the shear strength at the connection. A joint groove 14 is provided above the shear groove 13 to facilitate accurate docking.

[0028] In this embodiment, in order to improve the tensile strength of the UHPC beam and further facilitate weight reduction, the top plate 1 and web plate 4 of the UHPC beam are provided with longitudinal tensile reinforcement 7, which is arranged along the length of the UHPC beam. The UHPC horseshoe beam 5 is surrounded by horseshoe beam stirrups 9 located outside the longitudinal tensile reinforcement 7.

[0029] Furthermore, the construction of the ultra-high performance concrete beam in this embodiment includes the following steps: S1: Fabricate the UHPC beam casting template. The height H of the UHPC horseshoe beam 5 near the support is slightly greater than that at the mid-span position to facilitate the anchorage of the prestressing tendons 8 at the support and provide anchorage space for the prestressing tendon anchorage block 10 of the prestressing tendon 8.

[0030] S2: Place a steel mesh inside the casting formwork, wherein the steel mesh near the support point of the web 4 of the UHPC beam is densely arranged. Optionally, the steel mesh can be prepared according to the project requirements.

[0031] S3: Pour UHPC and cure to the specified age; S4: After the UHPC beam has been cured to the specified age, the prestressed tendons 8 are arranged and tensioned along the longitudinal prestressed ducts 6 in the UHPC horseshoe beam 5. The prestressed tendon anchor blocks 10 are set on the UHPC horseshoe beam 5 at the support point, and the anchor heads are sealed to facilitate further construction.

[0032] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An ultra-high performance concrete beam, characterized in that, The UHPC beam includes a UHPC beam top plate (1) and a UHPC beam web (4) connected below the UHPC beam top plate (1). The UHPC beam web (4) includes a UHPC horseshoe beam (5) connected below. The UHPC horseshoe beam (5) is provided with a plurality of longitudinal prestressing ducts (6). Prestressing tendons (8) are provided in the longitudinal prestressing ducts (6). The ends of the prestressing tendons (8) are anchored to the ends of the UHPC horseshoe beam (5) by prestressing tendon anchor blocks (10).

2. The ultra-high performance concrete beam according to claim 1, characterized in that, The prestressed tendon (8) is made of ordinary prestressed steel strand.

3. The ultra-high performance concrete beam of claim 1, wherein, The longitudinal prestressed ducts (6) are arranged in multiple circumferential directions along the cross section of the UHPC horseshoe beam (5).

4. The ultra-high performance concrete beam of claim 1, wherein, The UHPC beam is provided with steel fibers, and the prestressed tendon (8) is configured such that the steel fibers harden under tension when the UHPC beam is under tension.

5. The ultra-high performance concrete beam of claim 1, wherein, The web (4) of the UHPC beam is connected to the two sides by UHPC web reinforcing ribs (11), which connect the top plate (1) of the UHPC beam and the UHPC horseshoe beam (5), and the UHPC web reinforcing ribs (11) are located above the bottom support position (15) of the UHPC beam.

6. The ultra-high performance concrete beam according to claim 5, characterized in that The web (4) of the UHPC beam is of equal thickness, and the UHPC horseshoe beam (5) is provided with UHPC horseshoe beam heightening parts (12) with gradually increasing height near both ends. The bottom of the UHPC web reinforcing rib (11) is connected to the UHPC horseshoe beam heightening parts (12).

7. The ultra-high performance concrete beam of claim 5, wherein, The top plate (1) of the UHPC beam is provided with a top plate steel mesh (2), the web plate (4) of the UHPC beam is provided with a web plate steel mesh (3), and the web plate reinforcing rib (11) of the UHPC beam is provided with a reinforcing rib steel mesh connecting the top plate steel mesh (2) and the web plate steel mesh (3).

8. The ultra-high performance concrete beam according to claim 7, characterized in that The top plate (1) of the UHPC beam has joint ends on both sides for connecting the UHPC beam body, and the steel bars of the top plate steel mesh (2) extend laterally outward from the joint ends.

9. The ultra-high performance concrete beam according to claim 8, characterized in that A shear groove (13) is provided at the bottom thickened position of the joint end, and a joint groove (14) is provided above the shear groove (13).

10. The ultra-high performance concrete beam according to any one of claims 1-9, characterized in that, The top plate (1) and web plate (4) of the UHPC beam are provided with longitudinal tensile reinforcement (7), which is arranged along the length of the UHPC beam. The UHPC horseshoe beam (5) is surrounded by horseshoe beam stirrups (9) outside the longitudinal tensile reinforcement (7).

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