Prestressed component for deflection tensioning of composite beam bridge deck slab

Abstract

The utility model belongs to the technical field of building components, and particularly relates to a prestressed component for deflection tensioning of a composite beam bridge deck slab. Comprising a prestressed pipe, a steel strand harness, a deflection tensioning pipe and a tensioning jack. The plurality of prestressed pipes are pre-arranged in the bridge deck slab; the main body of the deflection tension pipe is in an upward bent pipe shape, and a horizontal pipe orifice is in butt joint with a pipe orifice at one end of the prestressed pipe through an anchor bearing plate; the area of the anchor bearing plate is larger than that of the prestressed pipe; the tensioning jack is arranged at an upward bent pipe orifice of the deflection tensioning pipe; the steel strand wire harness penetrates through the prestressed pipe, and one end of the steel strand wire harness extends out of the prestressed pipe, is guided upwards through the deflection tensioning device and is fixedly connected with the tensioning jack. Pre-pressure is provided for the bridge deck slab, the size of an anchor groove can be reduced through tensioning of the deflectors, the anchoring position can be placed in a wet joint area of the bridge deck slab, the bond stress of concrete and prestress is increased through anchor sealing of high-strength concrete, the anchoring performance is improved, construction is facilitated on the whole, and durability is good.

Description

Technical Field

[0001] This utility model belongs to the field of building component technology, specifically relating to a prestressed component for deflection tensioning of composite beam bridge deck. Background Technology

[0002] Composite beams, consisting of a lower steel beam and a top concrete bridge deck, fully utilize the material's performance characteristics and are widely used in bridges. However, due to the effects of tension, shrinkage, and creep on the bridge deck, cracking is a common problem. Prestressed steel strands are typically installed in the bridge deck to increase its crack resistance, ensuring a more reasonable stress distribution under load, thereby improving structural performance and saving materials.

[0003] The conventional methods for prestressing arrangement and tensioning of this type of component are: (1) setting prestress in the bridge deck and tensioning below the bridge deck by setting concrete tooth blocks at the bottom of the deck; (2) setting prestress in the bridge deck and tensioning above the bridge deck by opening slots at the top of the bridge deck.

[0004] For structure (1), tensioning is carried out below the bridge deck, requiring tensioning operation equipment and space under the bridge. Temporary supports can be used for tensioning under the bridge in the land section, while mobile maintenance vehicles are required for water operations. The construction costs are relatively high. Tensioning teeth are permanent components, which also affect the appearance of the structure. For structure (2), slots are cut at the top of the panel. Since the tensioning jacks require a certain amount of space, the slots need to be large, the reinforcing bars in the slots need to be cut off, and the overall integrity is poor after the slots are sealed and anchored. Summary of the Invention

[0005] The purpose of this utility model is to provide a prestressed component for deflection tensioning of composite beam bridge decks that has strong crack resistance, is easy to construct, and has low cost.

[0006] The prestressed member for deflection tensioning of composite beam bridge deck proposed in this utility model includes a prestressed tube, a steel strand bundle, a deflection tensioning tube, and a tensioning jack; wherein:

[0007] The prestressed pipes are of several types, and are pre-installed parallel to each other within the bridge deck along the width direction of the bridge deck.

[0008] The deflection tensioning tube body is in the shape of an upwardly curved tube (the upwardly curved tube body can avoid the adjacent bridge deck), and the horizontal tube opening and the tube opening at one end of the prestressed tube are connected by an anchor plate; the area of ​​the anchor plate is larger than the tube opening of the prestressed tube.

[0009] The tensioning jack is installed at the opening of the bend in the tensioning pipe.

[0010] The steel strand bundle passes through the prestressed tube, with one end extending out of the prestressed tube and then guided upward by a deflection tensioning device, where it is fixedly connected to the tensioning jack; wherein:

[0011] An anchor plate is provided at the other end of the prestressed pipe, and the other end of the steel strand bundle extends out of the prestressed pipe and is fixedly connected to the anchor plate to form single-end tensioning; or:

[0012] The other end of the prestressed tube is also equipped with a deflection tensioning tube and a tensioning jack. After the other end of the steel strand bundle extends out of the prestressed tube, it is guided upward by the deflection tensioning device and fixedly connected to the tensioning jack; thus forming a symmetrical double-end tensioning structure.

[0013] In this invention, during single-end tensioning, the steel strand bundle in each prestressed tube is divided into several steel strand branches. One end of each steel strand branch passes through a hole in a pre-set anchor plate on the concrete surface and is then secured by a compression sleeve, the cross-sectional area of ​​which is larger than the area of ​​the pre-set hole in the anchor plate. The other end of each steel strand branch is fixedly connected to a deflection tensioning tube and a tensioning jack. When the tensioning jack pulls the steel strand bundle, the other end of the bundle is restricted by the compression sleeve, forming a corresponding tensile force, thereby applying stress to the bridge deck.

[0014] In this invention, the total cross-sectional area of ​​the steel strand bundle is determined according to the stress condition, and the arrangement of each bundle should take into account the bridge deck size and the lateral distance required for tensioning and anchoring.

[0015] Typically, prestressed steel strands are installed in the bridge deck of composite beams to increase crack resistance. In this invention, prestressed ducts are arranged inside the bridge deck, and the steel strand bundles pass through the bridge deck as prestressing tendons. The number of prestressing tendons is determined according to the actual bridge dimensions. An anchor plate is installed at the connection point between the deflection tensioning pipe and the prestressing pipe. After the steel strand bundles pass through the anchor plate, they are led upward through the deflection tensioning pipe. The bridge deck is prestressed by jacks behind the deflection tensioning pipe. After tensioning, the jacks and deflection tensioning pipe are removed, and the inside of the prestressing duct is grouted to fill it with grout. After grouting, the anchor groove is sealed with high-strength concrete.

[0016] This invention provides preload to the bridge deck by tensioning the steel strand bundle through a deflection tensioning pipe, thereby changing the direction of the tensioning. The wet joint area of ​​the bridge deck can be directly used as the anchor groove, reducing the required anchor groove size (the wet joint area is the gap left between the bridge decks during installation), improving the overall integrity after the groove is sealed, and increasing the anchoring performance through high-strength concrete sealing. The overall design is easy to construct and has good durability.

[0017] The construction method of this utility model is as follows: bridge deck formwork and steel reinforcement construction, pre-embedded prestressed ducts, pouring bridge deck concrete, inserting prestressed strands (steel strand bundles) into the prestressed ducts, tensioning prestressing when the strength meets the requirements, grouting the prestressed ducts when the construction requirements are met, and backfilling the anchor grooves with concrete.

[0018] The advantages of this utility model are:

[0019] The prestressing material installed within the bridge deck is deflected out onto the deck for tensioning, reducing the required tensioning space. The tensioning point can be located at the relatively narrow wet joint between the bridge decks, satisfying the space requirement. High-strength concrete is used in the wet joint to increase the concrete's tensile strength and prestress bond strength. It also exhibits excellent durability and a pleasing structural appearance. After construction, the composite beam bridge deck demonstrates strong crack resistance, good durability, convenient construction, and low construction costs; moreover, it minimizes changes to the existing bridge structure's appearance and does not affect the overall aesthetic appeal of the bridge. Attached Figure Description

[0020] Figure 1 This is a top view of the layout of this utility model.

[0021] Figure 2 This is a schematic diagram of the prestressed pipe, deflection tensioning pipe and tensioning jack structure of this utility model.

[0022] Figure 3 This is a schematic diagram of the structure of a single-end tensioned steel strand bundle at the other end of a prestressed tube.

[0023] Figure 4 This is a schematic diagram showing the prestressed concrete filling process after prestressing tensioning is completed.

[0024] The numbers in the diagram are as follows: 1 is the bridge deck, 2 is the prestressed pipe, 3 is the steel strand bundle, 4 is the deflection tension pipe, 5 is the tension jack, 6 is the anchor groove, 7 is the steel strand branch line, 8 is the anchor plate, 9 is the extrusion sleeve, and 10 is the high-strength concrete. Detailed Implementation

[0025] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0026] Taking a composite beam cable-stayed bridge as an engineering example, the composite beam bridge deck is implemented using this new type of technology.

[0027] The main girder of this bridge is a composite beam, with a steel beam underneath and a concrete bridge deck 1 on top. Bridge deck 1 is prefabricated in sections, such as... Figure 1 The bridge deck 1 is arranged such that the gap between the bridge deck 1 and the bridge deck 1 is used as the anchor groove 6. Several prestressed pipes 2 with equal spacing are arranged in parallel inside the bridge deck 1 during prefabrication. After prefabrication and hoisting, the steel strand bundle 3 is inserted into the prestressed pipe 2.

[0028] One end of the prestressed pipe 2 is provided with a deflection tensioning pipe 4, and the other end is provided with a single anchor plate 8.

[0029] The steel strand bundle 3 is divided into four steel strand branches 7 inside the tube. The other end of each branch passes through a pre-set hole on the anchor plate 8 and is secured by a compression sleeve 9. The cross-sectional area of ​​the compression sleeve 9 is larger than the area of ​​the pre-set hole on the anchor plate 8. The other end of each branch is fixedly connected via a deflection tensioning tube 4 and a tensioning jack 5. Specifically, the branch passes through the tensioning jack 5 and is fixed by a tool anchor plate at the tail of the tensioning jack 5. Thus, when the tensioning jack 5 pulls the steel strand bundle 3, the other end of the bundle 3 is restricted by the compression sleeve 9, forming a corresponding tensile force, thereby applying stress to the bridge deck 1. Figure 3 As shown;

[0030] The deflection tensioning tube 4 is mainly in the shape of an upwardly curved tube, and the upwardly curved section of the tube can avoid the adjacent bridge deck 1. The upward bending angle can be 30~45°. Figure 2 As shown; the horizontal pipe opening and the pipe opening at one end of the prestressed pipe 2 are connected by an anchor plate; the area of ​​the anchor plate is larger than the pipe opening of the prestressed pipe 2.

[0031] The tensioning jack 5 is positioned at the opening of the upper bend of the deflection tensioning pipe 4;

[0032] The steel strand bundle 3 passes through the prestressed pipe 2, with one end extending out of the prestressed pipe 2 and then guided upward through the deflection tensioning pipe 4, where it is fixedly connected to the tensioning jack 5; as... Figure 2 As shown;

[0033] Start tensioning jack 5, which pulls the steel strand bundle 3. Due to the anchor plate 8, the steel strand bundle 3 begins to tighten, applying prestress to the bridge deck 1.

[0034] Prestressing is introduced above the bridge deck through a deflection tensioning pipe within the wet joint and tensioned by jacks. This reduces the space occupied by the wet joint and minimizes its size. After tensioning, the anchor plate is locked, the tensioning jacks and deflection tensioning pipe are removed, excess steel strands are cut off, the prestressing duct is grouted, and high-strength concrete is cast-in-place at the wet joint to form a whole.

[0035] In this embodiment, the standard precast bridge deck thickness is 240mm, with haunches on both sides at a height of 290mm; longitudinal prestressed steel strands 3 are installed in the bridge deck, using φ15.20mm low-relaxation steel strands with specifications of 5-φ15.20mm and a transverse spacing of 800mm; the height of the wet joint of the bridge deck is 300mm, and the cast-in-place wet joint is post-cast with high-performance concrete; the steel strand bundles are made of low-relaxation prestressed steel strands; the steel strand specifications are 1×5-φ15.20mm, and the nominal area of ​​a single steel strand is 140mm². 2 The standard strength is 1860 MPa, and the anchor control stress σcon = 1395 MPa.

[0036] Because the steel strand bundles are placed inside the bridge deck, they provide pressure to the bridge deck to increase its crack resistance. The total cross-sectional area of ​​the prestressed strands is determined based on the stress conditions under service. The arrangement of each steel strand should comprehensively consider the bridge deck dimensions and the tensioning requirements during construction, and they should be evenly and transversely distributed within the bridge deck.

[0037] This invention utilizes a prestressing mechanism within the bridge deck, which is then deflected out onto the bridge surface for tensioning. This reduces the required tensioning space, allowing the tensioning point to be positioned at the relatively narrow wet joint between the bridge deck panels, thus meeting the space requirements. The wet joint uses high-strength concrete, increasing the concrete's tensile strength and the prestress bond strength. It also exhibits excellent durability and a pleasing structural appearance. After construction, the composite beam bridge deck demonstrates strong crack resistance and durability, is easy to construct, and has low construction costs. Furthermore, it minimizes changes to the existing bridge structure's appearance and does not affect the overall aesthetic appeal of the bridge.

[0038] Although the above methods are illustrated and described as a series of structures for the sake of simplicity, it should be understood and appreciated that these methods are not specifically limited, as some structures may occur in different orders and / or concurrently with other actions from those illustrated and described herein or not illustrated and described herein but which may be understood by those skilled in the art, according to one or more embodiments.

[0039] The prior description of this disclosure is provided to enable any person skilled in the art to make or use this disclosure. Various modifications to this disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not intended to be limited to the examples and designs described herein, but should be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A prestressed member for deflection tensioning of composite beam bridge deck, characterized in that, This includes prestressed pipes, steel strand bundles, deflection tensioning pipes, and tensioning jacks; among which: The prestressed pipes are of several types, and are pre-installed parallel to each other within the bridge deck along the width direction of the bridge deck. The deflection tensioning tube body is in the shape of an upwardly curved tube, and the horizontal tube opening and the tube opening at one end of the prestressed tube are connected by an anchor plate; the area of ​​the anchor plate is larger than the tube opening of the prestressed tube. The tensioning jack is installed at the opening of the bend in the tensioning pipe. The steel strand bundle passes through the prestressed tube, with one end extending out of the prestressed tube and then guided upward by a deflection tensioning device, where it is fixedly connected to the tensioning jack; wherein: An anchor plate is provided at the other end of the prestressed pipe, and the other end of the steel strand bundle extends out of the prestressed pipe and is fixedly connected to the anchor plate to form single-end tensioning; or: The other end of the prestressed tube is also equipped with a deflection tensioning tube and a tensioning jack. After the other end of the steel strand bundle extends out of the prestressed tube, it is guided upward by the deflection tensioning device and fixedly connected to the tensioning jack; thus forming a symmetrical double-end tensioning structure.

2. The prestressed member according to claim 1, characterized in that, In the single-end tension state, the steel strand bundle in each prestressed tube is divided into several steel strand branches. One end of each steel strand branch passes through the hole in the anchor plate preset on the concrete surface and is then tightened by the extrusion sleeve. The cross-sectional area of ​​the extrusion sleeve is larger than the area of ​​the hole preset on the anchor plate. The other end of each steel strand branch is fixedly connected to a deflection tensioning pipe and a tensioning jack; when the tensioning jack pulls the steel strand bundle, the other end of the steel strand bundle is restricted by the compression sleeve, forming a corresponding tensile force, thereby applying stress to the bridge deck.

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