Steel-concrete composite beam combined after pre-tensioning and pre-stressing

Abstract

The utility model relates to the technical field of bridge engineering, and discloses a pre-tensioned pre-stressed and combined steel-concrete composite beam which comprises a steel beam and a concrete prefabricated bridge deck installed on the steel beam, a pre-stressed pipeline is arranged in the concrete prefabricated bridge deck, and ultra-high performance concrete is poured in a wet joint at the position of the pre-stressed pipeline. According to the technical scheme, the structural form of a traditional prestressed steel-concrete composite beam is improved, the adjacent prefabricated bridge deck slabs are connected through the ultra-high-performance concrete firstly, the steel beams and the prefabricated bridge deck slabs are connected into a whole by pouring the remaining wet joints after prestress tensioning is completed, it is guaranteed that prestress is completely applied to the bridge deck slabs, and the construction efficiency is improved. The stress of the concrete bridge deck and the steel beam is improved, the dry joints of the splicing matching surfaces of the concrete bridge deck are eliminated, and the diseases such as cracking and damage caused by local point contact of the bridge deck concrete due to poor contact of the dry joints of the splicing matching surfaces during prestress tensioning are completely eradicated.

Description

Technical Field

[0001] This utility model relates to the field of bridge engineering technology, and in particular to a steel-concrete composite beam that is prestressed and then assembled. Background Technology

[0002] A steel-concrete composite bridge is a structure that combines steel and concrete materials through shear connectors to share the load. It can fully utilize the good compressive strength of concrete and the good tensile strength of steel, and has the advantages of high stiffness and high load-bearing capacity.

[0003] To reduce steel consumption in bridge construction, lower project costs, minimize prefabrication and assembly work, and improve construction efficiency, an increasing number of steel-concrete composite beams are adopting a structure with fewer main beams. The larger spacing between the main beams results in significant tensile stress on the lower edge of the concrete bridge deck between two main beams under vehicle loads, leading to cracks in the concrete slab and affecting its strength and durability. Therefore, the common practice is to apply prestressed steel strands to the concrete bridge deck to counteract the tensile stress at the lower edge.

[0004] Chinese patent document CN113187152A discloses a "steel beam and steel-concrete composite beam". The steel beam includes an H-shaped beam, stiffening members, and multiple widening sections. The widening sections are located on the upper flange of the H-shaped beam, and the beam segment structure formed by two adjacent widening sections on the H-shaped beam is used to support the concrete slab. The stiffening members are located on the side of the web of the H-shaped beam, and their two ends are used to support the two flanges of the H-shaped beam. Along the length of the H-shaped beam, the stiffening members are positioned at the location of the widening sections on the upper flange. The stiffening members, the web of the H-shaped beam, and the two flanges form a box-shaped structure for pouring concrete. The above technical solution is prone to insufficient prestressing effect of the concrete slab, while the steel beam bears more pressure. Summary of the Invention

[0005] This utility model primarily addresses the technical problem that existing solutions often result in insufficient prestressing of the concrete slab while the steel beam bears more pressure. It provides a steel-concrete composite beam that is prestressed before assembly, improving upon the traditional prestressed steel-concrete composite beam structure. By using ultra-high performance concrete to first connect adjacent precast bridge decks, and then pouring the remaining wet joints after prestressing is complete, the steel beam and precast bridge deck are connected as a whole. This ensures that the prestress is fully applied to the bridge deck, improving the stress distribution on both the concrete bridge deck and the steel beam. It also eliminates dry joints at the splicing surfaces of the concrete bridge deck, preventing cracking and damage caused by poor contact at the dry joints during prestressing, which can lead to localized point contact in the bridge deck concrete.

[0006] The above-mentioned technical problems of this utility model are mainly solved by the following technical solution: This utility model includes a steel beam and a precast concrete bridge deck installed on the steel beam. The precast concrete bridge deck has prestressed ducts inside, and the wet joints at the locations of the prestressed ducts are filled with ultra-high performance concrete. Ultra-high performance concrete is an ultra-high strength fiber-reinforced concrete produced by using cement and mineral admixtures as cementing materials, combined with aggregates, admixtures, high-strength micro-steel fibers and / or non-metallic fibers, water, and other raw materials. Due to its ultra-high compressive, tensile, crack, and fatigue resistance mechanical properties, it has been extensively studied and widely used in the field of civil engineering. Ultra-high performance concrete has a short setting time and rapid early strength development; its compressive strength can reach 40-80 MPa in 1 day.

[0007] Preferably, a shear connector is provided on the top surface of the steel beam at the location of the non-prestressed duct. The shear connector, located on the top surface of the steel beam at the location of the non-prestressed duct, helps to integrate the steel beam and the concrete bridge deck by resisting relative slippage.

[0008] Preferably, ordinary wet-joint concrete is poured at the wet joints where there are no prestressed ducts. Debris at the remaining wet joint locations is cleared, the wet joint reinforcement is placed, tied, and welded, and finally, ordinary wet-joint concrete is poured at the remaining locations and cured to the required strength. The ordinary wet-joint concrete is located at the non-prestressed duct locations. Rubber pads or plastic films must not be laid on the contact surface between the ordinary wet-joint concrete and the steel beam. Prestressing tendons are first threaded and tensioned before the ordinary wet-joint concrete is poured.

[0009] Preferably, rubber pads or plastic films are laid on the top surface of the steel beams near the prestressing ducts to prevent effective connection between the ultra-high performance concrete and the precast concrete bridge deck. By first laying rubber pads or plastic films at the prestressing duct locations to prevent the ultra-high performance concrete from connecting with the steel beams, the steel beams are free from prestressing, thus improving the efficiency of prestressing application.

[0010] Preferably, the prestressing ducts of adjacent precast concrete bridge decks are aligned. The precast bridge decks are poured and cured in sections at the precast yard to achieve the required strength. After being stored for several months, they are transported to the site. Rubber strips are attached to the contact surfaces between the steel beams and the precast bridge decks. Once firmly attached, the precast bridge decks are hoisted, ensuring that the prestressing ducts of adjacent precast slabs are aligned during the hoisting process.

[0011] Preferably, prestressed corrugated pipes are installed within the wet joint area of ​​adjacent precast concrete bridge decks, connecting to the prestressed ducts that run through the adjacent precast bridge decks. Rubber pads or plastic films are laid on the top surface of the steel beams near the prestressed duct locations. Then, the prestressed corrugated pipes within the wet joint area are installed, connecting to the prestressed ducts that run through the adjacent precast bridge decks. The continuity and sealing of the prestressed ducts are checked to prevent grout leakage. Ultra-high performance concrete is then poured into the wet joint at the location of the prestressed ducts and cured.

[0012] Preferably, prestressed steel strands are installed within the prestressed ducts. Prestressed steel strand tensioning and grouting: After the ultra-high performance concrete reaches 1 day of age, with a compressive strength of not less than 40 MPa and 90% of the standard compressive strength of ordinary concrete for precast bridge decks, the prestressed steel strands are tensioned using jacks. Tensioning employs a stress control method, with elongation values ​​used for verification. Intelligent grouting or circulating grouting processes are used for grouting operations, requiring the duct to be densely and fully grouted.

[0013] Preferably, the thickness of the ultra-high performance concrete in the wet joint is consistent with the thickness of the precast concrete bridge deck.

[0014] The beneficial effects of this utility model are: it improves the structural form of traditional prestressed steel-concrete composite beams, and uses ultra-high performance concrete to first connect adjacent precast bridge decks. After the prestressing is completed, the remaining wet joints are poured to connect the steel beams and precast bridge decks into a whole. This ensures that the prestress is fully applied to the bridge deck, improves the stress on the concrete bridge deck and the steel beam, eliminates the dry joints on the splicing and matching surfaces of the concrete bridge deck, and prevents cracking, damage and other defects caused by poor contact of the dry joints on the splicing and matching surfaces during prestressing tension. Attached Figure Description

[0015] Figure 1 This is a three-dimensional structural schematic diagram of this utility model.

[0016] Figure 2 This is a schematic diagram of the cross-section of a structure of this utility model (non-prestressed pipe location).

[0017] Figure 3 This is a schematic diagram of the cross-section (position of prestressed pipe) of a structure according to this utility model.

[0018] Figure 4 This is a schematic diagram of the cross-section (position of the steel beam) of a structure according to this utility model.

[0019] Figure 5 This is a planar schematic diagram of the present invention.

[0020] Figure 6 This is an installation diagram of a steel-concrete composite beam according to this utility model.

[0021] In the diagram, 1 is a steel beam, 2 is a precast concrete bridge deck, 3 is a shear connector, 4 is a prestressed steel strand, 5 is a prestressed duct, 6 is ultra-high performance concrete, and 7 is ordinary concrete with wet joints. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this application will be further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only one preferred embodiment of this application and are only used to explain this application. They do not limit the scope of protection of this application. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0023] Steel-concrete composite beams are generally prestressed after the steel beam and concrete slab form an integral whole. However, this method usually applies 20%-40% of the prestress to the steel beam, resulting in insufficient prestressing effect in the concrete slab and the steel beam bearing more pressure.

[0024] In addition, some steel-concrete composite beams are prestressed before the steel beams and concrete slabs are integrated, employing a construction process similar to segmental precast bridges. Epoxy resin is applied as an adhesive to the mating surfaces of the two concrete bridge decks. To prevent grout leakage and blockages at the mating surfaces during grouting, a 10mm thick epoxy resin-soaked sponge gasket or other reliable method is often attached to the prestressing duct openings at the mating surfaces. While the sponge gasket solves the grouting-related problems, it creates a dry joint between the mating surfaces of the two concrete slabs. Even after using emulsified asphalt grouting during bridge deck installation, the dry joint cannot be guaranteed to be sealed, leading to water leakage and significantly affecting the appearance and durability of the bridge deck. Meanwhile, due to the approximately 2% cross slope on each of the left and right bridge decks, there is a gap at the joint between the left and right bridge decks at the bridge axis, which is wider at the top and narrower at the bottom, making it difficult to align them completely. This irregularly shaped and smaller contact surface makes it easy for the bridge deck to crack or break at this location when the steel strands are tensioned, affecting the structural integrity and load-bearing capacity.

[0025] Before discussing the exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts describe the operations (or steps) as sequential processes, many of the operations (or steps) can be performed in parallel, concurrently, or simultaneously. Furthermore, the order of the operations can be rearranged. The process can be terminated when its operation is completed, but it may also have additional steps not included in the figures; the process may correspond to a method, function, procedure, subroutine, subroutine, etc.

[0026] The technical solution of this utility model will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0027] Example: This example describes a steel-concrete composite beam that is prestressed before assembly, such as... Figure 1 , Figure 5 As shown, the structure includes a steel beam 1 and a precast concrete bridge deck 2 installed on the steel beam 1. The precast concrete bridge deck 2 contains prestressed ducts 5, and the wet joints at the locations of the prestressed ducts 5 are filled with ultra-high performance concrete (UHVPC). The thickness of the UHVPC 6 at the wet joints is consistent with the thickness of the precast concrete bridge deck 2. UHVPC is an ultra-high strength fiber-reinforced concrete produced using cement and mineral admixtures as cementing materials, combined with aggregates, admixtures, high-strength micro-steel fibers and / or non-metallic fibers, water, and other raw materials. Due to its extremely high compressive, tensile, crack, and fatigue resistance mechanical properties, it has been extensively studied and widely applied in the field of civil engineering. UHVPC has a short setting time and rapid early strength development; its compressive strength can reach 40-80 MPa in 1 day. A rubber pad or plastic film is laid on the top surface of the steel beam 1 near the location of the prestressed ducts, and the UHVPC 6 and the precast concrete bridge deck 2 do not form an effective connection with the steel beam 1. Figure 4 As shown, at the location of the prestressing ducts, rubber pads or plastic films are first laid between the steel beams and the concrete bridge deck to prevent the ultra-high performance concrete from connecting with the steel beams, so that the steel beams are not subjected to prestressing and the prestressing application efficiency is improved.

[0028] Shear connectors are installed on the top surface of the steel beams located at the non-prestressed duct locations. These shear connectors, situated on the top surface of the steel beams at the non-prestressed duct locations, help to integrate the steel beams and concrete bridge deck by resisting relative slippage.

[0029] like Figure 2 As shown, ordinary concrete is poured at the wet joints where there are no prestressed ducts. After cleaning away debris at the remaining wet joint locations, the reinforcing steel bars are placed, tied, and welded. Finally, the remaining ordinary concrete is poured and cured to the required strength. The ordinary concrete for the wet joints is located at the non-prestressed duct locations. Rubber pads or plastic films must not be laid on the contact surface between the ordinary concrete and the steel beam. The transverse steel tendons are first threaded and tensioned before the ordinary concrete is poured.

[0030] The prestressing ducts 5 of adjacent precast concrete bridge deck 2 are aligned. The precast bridge decks are poured and cured in the precast yard to the required strength, and then stored for several months before being transported to the site. Rubber strips are pasted on the contact surfaces of the steel beams and the precast bridge decks. After the strips are firmly pasted, the precast bridge decks are hoisted. During the hoisting process, the prestressing ducts of adjacent precast decks are kept aligned.

[0031] like Figure 3As shown, prestressed corrugated pipes are installed within the wet joint area of ​​adjacent precast concrete bridge decks 2, connecting to the prestressed ducts that run through the adjacent precast bridge decks. Rubber pads or plastic films need to be laid on the top surface of the steel beams near the prestressed duct locations. Then, the prestressed corrugated pipes within the wet joint area are installed, connecting to the prestressed ducts that run through the adjacent precast bridge decks. The continuity and sealing of the prestressed ducts are checked to prevent grout leakage. Ultra-high performance concrete is then poured into the wet joint at the location of the prestressed pipes and cured.

[0032] The prestressed duct 5 contains the prestressed steel strands 4. Prestressed steel strand tensioning and grouting: After the ultra-high performance concrete reaches 1 day of age and its compressive strength is not less than 40 MPa and 90% of the standard compressive strength of ordinary concrete for precast bridge decks, the prestressed steel strands are tensioned using jacks. Tensioning employs a stress control method, with elongation values ​​used for verification. Intelligent grouting or circulating grouting processes are used for grouting operations, requiring the duct to be densely and fully grouted.

[0033] like Figure 4 As shown, the steel-concrete composite beam, which is prestressed and then assembled, includes a steel beam 1, multiple precast concrete bridge deck panels 2, shear connectors 3, prestressed steel strands 4, prestressed ducts 5, ultra-high performance concrete 6, and ordinary concrete for wet joints 7. The precast concrete bridge deck panels 2 are placed on top of the steel beam 1. Ultra-high performance concrete 5 is poured at the wet joint of the two at the prestressed duct location 4, while ordinary concrete 7 is poured at the remaining wet joints. The shear connectors 3 are located on the steel beam 1 at locations without prestressed ducts, and they prevent relative slippage, thus forming a unified structure between the steel beam 1 and the precast concrete bridge deck panels 2.

[0034] The steel beam 1 can be made of various strength grades of steel, such as Q235, Q355, and Q420. The cross-section can be selected from various forms, including I-beams, closed box girders, and open channel beams, depending on the stress conditions. The steel beam 1 is manufactured in the factory and then connected on-site by welding or bolting to form a whole. Shear connectors 3 must be installed on the top plate of the steel beam 1. During factory processing, the shear connectors must be precisely positioned according to the design documents to ensure that they do not conflict with the precast concrete bridge deck 2, the protruding reinforcing bars of the bridge deck, or the prestressed steel strands 4.

[0035] The precast concrete bridge deck 2 is factory-prefabricated using ordinary concrete with a strength grade of C30-C60 and a thickness between 220mm and 300mm. Prestressed ducts 5 are installed internally as needed, and their arrangement must strictly adhere to the design documents during prefabrication. Before leaving the factory, adjacent precast concrete bridge decks must be trial-assembled to ensure that the prestressed ducts 5 are aligned correctly.

[0036] The shear connector 3 is welded to the top plate of steel beam 1 during its fabrication in the steel beam 1 factory. Various methods can be used, such as welded stud connectors, perforated plate connectors, and structural steel connectors. This resists relative slippage, connecting steel beam 1 and the precast concrete bridge deck 2 into a single unit. To ensure that steel beam 1 and precast concrete bridge deck 2 do not form an effective connection during prestressing, the shear connector 3 must not be placed near the wet joints of the ultra-high performance concrete 6 in the prestressing duct 5. This ensures that steel beam 1 is essentially unaffected by prestressing, improving the efficiency of prestressing application.

[0037] The prestressed steel strands 4 are selected from high-strength, low-relaxation steel strands of φs15.2-2 to φs15.2-5, with a spacing between 0.4 and 1.5 m, according to the stress requirements. The prestressed ducts 5 must be used in conjunction with the prestressed steel strands 4, and the duct extension and connection of adjacent precast concrete bridge decks must be completed before the ultra-high performance concrete is poured at the wet joint.

[0038] The ultra-high performance concrete 6, located at the wet joint near the prestressed duct 5, must be a product with a short setting time and high early strength. The compressive strength of the ultra-high performance concrete at 1 day of age must reach 40-80 MPa, and not be less than 90% of the standard value of the compressive strength of ordinary concrete in precast slabs. The thickness of the ultra-high performance concrete at the wet joint should be consistent with the thickness of the precast concrete bridge deck 2, and the width should be reasonably selected based on the stress requirements and cost control.

[0039] Before pouring the ultra-high performance concrete 6, rubber pads or plastic films need to be laid on the contact surface between the ultra-high performance concrete 6 and the steel beam 1 to ensure that the ultra-high performance concrete 6 and the precast concrete bridge deck 2 do not form an effective connection with the steel beam 1, so that the prestress effect is basically applied to the concrete bridge deck, which improves the prestressing efficiency and improves the stress on the steel beam and the concrete bridge deck.

[0040] like Figure 6 As shown, the construction steps for the prestressed steel-concrete composite beam of this application include:

[0041] Step 1: Steel Beam 1 Fabrication and On-site Assembly: Steel Beam 1 is fabricated in the factory. During fabrication, the longitudinal steel beams, transverse steel beams, stiffening ribs, and shear connectors 3 are assembled strictly according to the design documents to ensure that there is no conflict with the precast concrete bridge deck 2, the protruding steel bars of the bridge deck, and the prestressed steel strands 4. After the steel beam 1 is fabricated, it is transported to the site and connected by welding or bolting to form a whole.

[0042] Step Two: Precast Concrete Bridge Panel 2 Fabrication and On-site Installation: The precast concrete bridge panel 2 is precast in sections at the prefabrication yard. During casting, the prestressing ducts 5 are placed simultaneously. It is crucial to ensure the top and bottom surfaces of the bridge panel are flat, especially the contact surface between the precast concrete bridge panel 2 and the steel beam 1, where the flatness deviation should not exceed 2mm to ensure a tight fit after on-site installation. After the precast concrete bridge panel 2 has cured to the required strength, it is stored at the prefabrication yard for several months to allow for sufficient early shrinkage and creep development, thereby reducing the risk of cracking. After reaching the required storage period, the precast concrete bridge panel 2 is transported to the site. Before installation, debris on the top surface of the steel beam 1 is cleaned, and 10×20mm rubber strips are adhered to the contact surface between the steel beam 1 and the precast concrete bridge panel 2. Once firmly adhered, the precast concrete bridge panel 2 is hoisted to the designed position using lifting equipment. During hoisting, the prestressing ducts 5 of adjacent precast concrete bridge panels 2 are aligned one-to-one, with a misalignment not exceeding 5mm.

[0043] Step 3: Connect the prestressed duct 5 and pour the ultra-high performance concrete 6 at the wet joint of the duct location: Rubber pads or plastic films need to be laid on the top surface of the steel beam near the prestressed duct location 5. Then, install the prestressed corrugated pipe within the wet joint area, connect the prestressed duct 5 that runs through the two adjacent precast concrete bridge decks 2, and check the continuity and sealing of the prestressed duct 5 to prevent grout leakage. Pour the ultra-high performance concrete 6 at the wet joint of the prestressed duct 5 and cure it.

[0044] Step 4: Tensioning and Grouting of Prestressed Steel Strands 4: After the ultra-high performance concrete reaches 6 years of age and 1 day of curing, with a compressive strength of not less than 40 MPa and 90% of the standard compressive strength of ordinary concrete in the precast bridge deck 2, the prestressed steel strands 4 are tensioned using jacks. Tensioning employs a stress control method, with elongation values ​​used for verification. After reaching the design control stress, the load is held for 5 minutes, and the deviation between the actual elongation value and the theoretical elongation value is controlled within ±6%. Within 48 hours after tensioning and anchoring, intelligent grouting or circulating grouting processes are used for grouting operations, requiring the grouting of the pipes to be dense and full.

[0045] Step 5: Pour ordinary concrete 7 for the remaining wet joint: After the prestressed steel strands 4 are tensioned and grouted, first clean up the debris in the remaining wet joint, place, tie and weld the wet joint reinforcement, and finally pour ordinary concrete 7 for the remaining wet joint and cure it to the required strength.

[0046] advantage:

[0047] 1. The steel beam processing and concrete slab prefabrication of this application can be completed in the factory. The wet joint concrete was poured in batches on site. The ultra-high performance concrete of the wet joint located at the prestressed duct only needs to be cured for 1 day before tensioning, which speeds up the construction and ensures the construction progress.

[0048] 2. In this application, ultra-high performance concrete is only used at the prestressed duct joints, while ordinary concrete is used at the other wet joints, which limits the amount of ultra-high performance concrete used in the whole bridge and ensures that the project cost is controllable.

[0049] 3. The wet joint at the prestressed duct in this application uses ultra-high performance concrete. Before pouring the ultra-high performance concrete, rubber pads or plastic films are laid to prevent the ultra-high performance concrete from connecting with the steel beam. Therefore, when prestressing is applied, the steel beam and the concrete slab do not form an effective connection, so that the prestressing effect is fully applied to the concrete bridge deck, which improves the prestressing application efficiency and improves the stress on the steel beam and the concrete bridge deck.

[0050] 5. In this application, the wet joints located at non-prestressed duct locations are constructed using ordinary concrete, and the steel beams at these locations are equipped with shear connectors. After prestressing tensioning is completed, the remaining ordinary wet joint concrete is poured to ensure that the joints form a unified whole and share the load.

[0051] 6. This application differs from the conventional dry-jointing process of prestressing steel-concrete composite beams, which are prestressed and then assembled. It eliminates the dry joints at the splicing and matching surfaces, and prevents cracking, damage, and other defects caused by poor contact at the dry joints of the splicing and matching surfaces during prestressing tension, which can lead to local point contact of the bridge deck concrete.

[0052] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this application. The above embodiments only express several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art to which this application pertains can make various modifications or additions to the described specific embodiments or use similar methods to substitute them, but without departing from the spirit of this application or exceeding the scope defined by the appended claims. For those skilled in the art, multiple variations and improvements can be made without departing from the concept of this application. Therefore, the scope of protection of this application should be determined by the appended claims.

Claims

1. A pre-tensioned prestressed post-combined steel-concrete composite beam, characterized in that, The application relates to a steel beam (1) and a prefabricated concrete bridge deck (2) installed on the steel beam (1), wherein the prefabricated concrete bridge deck (2) is internally provided with prestressed pipes (5), the wet joint at the position of the prestressed pipes (5) is filled with super high performance concrete (6), prestressed bellows are installed in the range of the wet joint of adjacent prefabricated concrete bridge decks (2), and the prestressed pipes are connected through the adjacent prefabricated bridge decks.

2. The pre-tensioned and post-combined steel-concrete composite beam according to claim 1, characterized in that, A shear connector is arranged on the top surface of the steel beam at the position of the non-prestressed pipe.

3. The pre-tensioned and post-combined steel-concrete composite beam according to claim 1, characterized in that, The wet joint at the position of the non-prestressed pipe is filled with wet joint ordinary concrete (7).

4. The pre-tensioned and post-combined steel-concrete composite beam according to claim 1, characterized in that, A rubber pad or plastic film is arranged on the top surface of the steel beam (1) near the position of the prestressed pipe, and the super high performance concrete (6) and the prefabricated concrete bridge deck (2) are not effectively connected with the steel beam (1).

5. The pre-tensioned and post-combined steel-concrete composite beam according to claim 1, characterized in that, The prestressed pipes (5) of adjacent prefabricated concrete bridge decks (2) are aligned.

6. The pre-tensioned and post-combined steel-concrete composite beam according to claim 5, characterized in that, Steel strands are arranged in the prestressed pipes (5).

7. The pre-tensioned and post-combined steel-concrete composite beam according to claim 1 or 2 or 3 or 4, characterized in that, The thickness of the wet joint super high performance concrete (6) is consistent with the thickness of the prefabricated concrete bridge deck (2).

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