A new type of UHPC-steel composite structure

Abstract

The utility model relates to bridge engineering technical field especially relates to a novel UHPC - steel combined structure. Including I -beam, the I -beam surface layer is equipped with bearing capacity reinforcing structure, and the I -beam all around pours concrete and forms steel - concrete combined structure, and the upper end of steel - concrete combined structure is provided with UHPC layer, and the lower end of steel - concrete combined structure is equipped with carbon fiber cloth. The carbon fiber reinforcement is set in the lower end of steel - concrete combined structure, utilizes its excellent fatigue resistance and tensile property, greatly reduces the probability of easy fracture of the section steel under the fatigue load, and simultaneously can flexibly select carbon fiber cloth or carbon fiber plate, and only lays in the stress concentration area, effectively controls the engineering cost.

Description

Technical Field

[0001] This utility model relates to the field of bridge engineering technology, and in particular to a novel UHPC-steel composite structure. Background Technology

[0002] Traditional bridge decks mostly use reinforced concrete structures or steel-concrete composite structures. Although traditional steel-concrete composite decks have optimized the balance between self-weight and load-bearing capacity to a certain extent, they still face technical bottlenecks such as complex construction procedures, easy cracking of cast-in-place wet joints in the negative bending moment zone at the pier top, and poor synergistic stress effect due to insufficient interface bonding performance.

[0003] As bridge engineering develops towards longer spans, lighter weight, and longer lifespans, traditional structures can no longer meet the higher performance requirements. Ultra-high performance concrete (UHPC), as a new type of cement-based composite material, is gradually being used in bridge engineering due to its ultra-high strength, ultra-high toughness, excellent crack resistance, and durability.

[0004] However, existing UHPC-steel composite bridge decks still have many shortcomings in practical applications: First, the interfacial bond strength between the steel and concrete is insufficient, making relative slippage prone to occur, resulting in the two not being able to fully cooperate in bearing the load and restricting the overall load-bearing capacity of the structure; second, under long-term vehicle fatigue loads, the steel in the bridge deck is prone to fatigue damage, especially in stress concentration areas, which can easily lead to fracture failure and affect structural safety. Furthermore, the ease of construction and economy of bridge deck construction are also key factors that need to be considered in engineering applications.

[0005] Therefore, there is an urgent need to develop a new type of UHPC-steel composite bridge deck structure with reasonable structural design, good component coordination, and excellent load-bearing capacity. Utility Model Content

[0006] The purpose of this utility model is to solve the problems existing in the prior art by proposing a new UHPC-steel composite structure.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A novel UHPC-steel composite structure includes an I-beam, the surface of which is provided with a load-bearing reinforcement structure, and concrete is poured around the I-beam to form a steel-concrete composite structure. A UHPC layer is provided at the upper end of the steel-concrete composite structure, and carbon fiber cloth is provided at the lower end of the steel-concrete composite structure.

[0008] Preferably, the load-bearing capacity strengthening structure includes several wing plates one and several wing plates two, with the wing plates one arranged in parallel and the wing plates two arranged in parallel. The wing plates one and the wing plates two are intersected to form a reinforcing mesh, which is placed on the surface of the I-beam.

[0009] Preferably, the surface of the I-beam is provided with a plurality of X-shaped grooves at intervals along the length direction, and the intersection of a plurality of wing plates one and a plurality of wing plates two is embedded in the grooves.

[0010] Preferably, the first wing plate has a first insertion port on its surface, and the second wing plate has a second insertion port at its lower end. The first wing plate and the second wing plate are arranged crosswise through the insertion of the first insertion port and the second insertion port, so that the surfaces of the first wing plate and the second wing plate are flush.

[0011] Preferably, the width of the lower flange of the I-beam is greater than the width of the upper flange.

[0012] Preferably, the load-bearing capacity strengthening structure further includes spokes disposed on both sides of the web, the spokes having a C-shaped cross-section, the lower end face of the spokes resting on the lower flange surface of the I-beam, and the upper end face of the spokes abutting against the lower end faces of flange one and flange two.

[0013] Preferably, the spokes are detachably mounted on the I-beam.

[0014] Preferably, the carbon fiber cloth is fixed to the lower end of the steel-concrete composite structure with epoxy resin adhesive.

[0015] Preferably, the carbon fiber cloth can be replaced with carbon fiber sheet.

[0016] Compared with the prior art, this utility model provides a novel UHPC-steel composite structure, which has the following beneficial effects: 1. This utility model involves specifically setting carbon fiber reinforcements at the lower end of a steel-concrete composite structure. Utilizing its excellent fatigue resistance and tensile strength, it greatly reduces the probability of steel fracture under fatigue load. At the same time, carbon fiber cloth or carbon fiber plates can be flexibly selected, and it is only laid in areas of stress concentration, effectively controlling project costs.

[0017] 2. This utility model, by setting up a load-bearing capacity strengthening structure, utilizes the reinforcing mesh formed by the intersection of wing plate one and wing plate two to significantly improve the interfacial bonding strength between the I-beam and the concrete, effectively avoids relative slippage, achieves synergistic force sharing between the two, and enhances the overall load-bearing capacity of the bridge deck.

[0018] 3. In this utility model, each component adopts a modular design, with interlocking joints between the wing plates and detachable installation of the spokes, which simplifies the construction process and improves installation efficiency.

[0019] Other advantages, objectives and features of this invention will be set forth in part in the description which follows; and in part will be apparent to those skilled in the art upon examination of the following description; or may be taught from practice of this invention. Attached Figure Description

[0020] Figure 1This is a partial cross-sectional schematic diagram of the novel UHPC-steel composite structure of this utility model.

[0021] Figure 2 For the present utility model Figure 1 A plan view after the concrete grout has been removed.

[0022] Figure 3 For the present utility model Figure 1 A 3D schematic diagram after removing the UHPC layer.

[0023] Figure 4 For the present utility model Figure 3 A three-dimensional schematic diagram after removing wing plate one and wing plate two.

[0024] Figure 5 This is a three-dimensional schematic diagram of wing plate one and wing plate two of this utility model.

[0025] Figure 6 For the present utility model Figure 3 A top-down view.

[0026] In the diagram: 1. I-beam; 2. Concrete grout; 3. Epoxy resin adhesive; 4. Carbon fiber cloth; 5. UHPC layer; 6. Load-bearing reinforced structure; 61. Wing plate one; 62. Wing plate two; 63. Groove; 64. Socket one; 65. Socket two; 66. Spokes; 67. Stud. Detailed Implementation

[0027] The following will refer to the appendix in the embodiments of this utility model. Figure 1-6 The technical solutions in the embodiments of this utility model will be clearly and completely described. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments.

[0028] Example 1: To address the problems existing in the prior art, this example provides a novel UHPC-steel composite structure, including I-beams 1. Several groups of I-beams 1 are evenly spaced along the width of the construction surface, and several groups of I-beams 1 are arranged parallel to each other along the length of the construction surface. Concrete grout 2 is poured around the I-beams 1 to form a steel-concrete composite foundation structure, serving as the foundation bearing point.

[0029] The steel-concrete composite structure has a UHPC layer 5 on top (either a precast formwork can be used, or the UHPC can be poured on the surface after the steel-concrete composite structure is poured to form the UHPC layer 5), which constitutes a UHPC-steel composite structure. This achieves synergistic stress distribution between steel and UHPC, giving full play to the tensile strength of steel and the compressive and crack resistance of UHPC. It can significantly reduce the self-weight of the structure, simplify bridge construction, and improve the durability of the structure.

[0030] However, when UHPC-steel composite beams are subjected to fatigue loads, fatigue fracture failure mode of the lower steel section may occur. Therefore, in the fatigue stress concentration areas corresponding to the negative bending moment at the bottom of the I-beam and the top of the pier, carbon fiber reinforced components (such as epoxy resin adhesive 3) are fixed with epoxy adhesive (such as epoxy resin adhesive 3). Carbon fiber cloth 4 or carbon fiber plate can be selected. Since carbon fiber cloth 4 has many advantages such as light weight, good fatigue resistance, and good tensile strength, it can make up for the deficiencies of steel and enhance the fatigue resistance of the composite structure.

[0031] While the application of high-performance reinforcement materials such as carbon fiber can improve fatigue resistance, their high price and the significant increase in engineering costs due to widespread application limit their large-scale promotion. Therefore, carbon fiber cloth 4 is only used in certain areas to work in conjunction with the steel profile. This is also the purpose of this scheme, which only sets carbon fiber cloth 4 on the bottom: the bottom is the area where fatigue failure is more severe, and reinforcement only at the bottom can achieve a good reinforcement effect while reducing costs.

[0032] In Example 2, to enhance the overall strength of the steel-concrete composite structure, a load-bearing reinforcement structure 6 is provided on the surface of the I-beam 1. The load-bearing reinforcement structure 6 includes several first flanges 61 and second flanges 62. The first flanges 61 are arranged in parallel with each other, and the second flanges 62 are arranged in parallel with each other. The first flanges 61 and the second flanges 62 are intersected to form a reinforcing mesh, which is placed on the surface of the I-beam 1 to enhance the connection stability between the I-beam 1 and the concrete, improve the interface's cooperative stress-bearing capacity, and also enhance the support force on the UHPC layer 5.

[0033] Furthermore, the surface of the I-beam 1 is provided with a plurality of X-shaped grooves 63 spaced along the length direction, and the intersection of a plurality of wing plates 61 and a plurality of wing plates 62 is embedded in the grooves 63, further defining the position of the reinforcing mesh and preventing displacement when subjected to force.

[0034] Furthermore, the surface of the first wing plate 61 is provided with a first insertion port 64, and the lower end of the second wing plate 62 is provided with a second insertion port 65. The first wing plate 61 and the second wing plate 62 are cross-set through the insertion and cooperation of the first insertion port 64 and the second insertion port 65, and the surfaces of the two are flat to enhance the tightness of the splicing of the reinforcing mesh.

[0035] Furthermore, the lower flange width of the I-beam 1 is greater than the upper flange width, which is adapted to the stress characteristics of the lower part of the bridge deck bearing a larger load and optimizes the stress performance of the cross section; at the same time, it also provides some clearance for the reinforcing mesh.

[0036] Example 3: To further enhance the overall strength, the load-bearing capacity strengthening structure 6 is further optimized: The load-bearing capacity strengthening structure 6 also includes spokes 66 disposed on both sides of the web. The spokes 66 have a C-shaped cross-section. The lower end face of the spokes 66 rests on the lower flange surface of the I-beam 1, and the upper end face of the spokes 66 abuts against the lower end faces of flange 1 61 and flange 2 62. The spokes 66 between two adjacent I-beams 1 are fully penetrated by a set of studs 67 and locked with nuts; while the studs 67 between the same I-beam 1 and the left and right I-beams 1 are staggered. This not only enhances the shear stiffness and stability of the web of the I-beam 1, but also provides effective support for the reinforcing mesh, further improving the overall strength of the load-bearing capacity strengthening structure 6.

[0037] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

[0038] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0039] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A novel UHPC-steel composite structure, characterized in that, It includes an I-beam (1), the surface of which is provided with a load-bearing capacity strengthening structure (6), and concrete is poured around the I-beam (1) to form a steel-concrete composite structure. A UHPC layer (5) is provided at the upper end of the steel-concrete composite structure, and carbon fiber cloth (4) is provided at the lower end of the steel-concrete composite structure.

2. The novel UHPC-steel composite structure according to claim 1, characterized in that, The load-bearing capacity strengthening structure (6) includes several wing plates one (61) and several wing plates two (62). The several wing plates one (61) are arranged in parallel with each other, and the several wing plates two (62) are arranged in parallel with each other. The several wing plates one (61) and several wing plates two (62) are arranged in a cross pattern to form a strengthening mesh, and the strengthening mesh is placed on the surface of the I-beam (1).

3. The novel UHPC-steel composite structure according to claim 2, characterized in that, The surface of the I-beam (1) is provided with a plurality of X-shaped grooves (63) spaced along the length direction, and a plurality of wing plates one (61) and a plurality of wing plates two (62) are embedded in the grooves (63) at the intersection.

4. The novel UHPC-steel composite structure according to claim 3, characterized in that, The surface of the first wing plate (61) is provided with a first socket (64), and the lower end of the second wing plate (62) is provided with a second socket (65). The first wing plate (61) and the second wing plate (62) are arranged crosswise by the insertion and cooperation of the first socket (64) and the second socket (65), so that the surfaces of the first wing plate (61) and the second wing plate (62) are flat.

5. The novel UHPC-steel composite structure according to claim 2, characterized in that, The width of the lower flange of the I-beam (1) is greater than the width of the upper flange.

6. The novel UHPC-steel composite structure according to claim 5, characterized in that, The load-bearing capacity strengthening structure (6) also includes spokes (66) on both sides of the web. The spokes (66) have a C-shaped cross section. The lower end face of the spokes (66) rests on the lower flange surface of the I-beam (1), and the upper end face of the spokes (66) abuts against the lower end face of flange one (61) and flange two (62).

7. The novel UHPC-steel composite structure according to claim 6, characterized in that, The spokes (66) are detachably mounted on the I-beam (1).

8. The novel UHPC-steel composite structure according to claim 1, characterized in that, The carbon fiber cloth (4) is fixed to the lower end of the steel-concrete composite structure by epoxy resin adhesive (3).

9. The novel UHPC-steel composite structure according to claim 1, characterized in that, The carbon fiber cloth (4) can be replaced with a carbon fiber plate.

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