Bridge anchorage-free prestress reinforcing device and reinforcing method

Abstract

The invention discloses an anchorage-device-free prestress reinforcing device and method for a bridge, and the anchorage-device-free prestress reinforcing device for the bridge comprises a plurality of prestress components which are fixed on the bottom surface of a beam body at intervals through bonding layers; the stress dispersion layers fixedly cover the two ends of the bottom face of the beam body, and the stress dispersion layers are arranged between the bottom face of the beam body and the ends of the prestressed components; and the heating device is used for heating the prestressed components. According to the method, the construction efficiency of bridge prestress reinforcement is effectively improved, the construction difficulty is reduced, and the problems of stress concentration and unstable reinforcement effect existing in other external prestress are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of beam reinforcement, and more specifically, to a bridge anchorless prestressed reinforcement device and reinforcement method. Background Art

[0002] Traditional prestressed reinforcement methods often include prestressed materials, steering blocks, anchor blocks, anchor pads, clamps and clips. During the construction process, it is necessary to drill holes in the bottom of the concrete to plant reinforcement, then weave steel cages, lay prestressed pipes and anchor devices, and then set up formwork supports; in order to achieve concrete pouring, it is often necessary to drill holes in the bridge deck for pouring, which not only destroys the original bridge structure, but also affects the reinforcement effect due to the loose concrete pouring; at the same time, the prestressing tensioning work needs to wait for 28 days after the concrete pouring. This traditional method has the disadvantages of uncontrollable quality, long construction period, cumbersome process, high cost, and stress concentration in the anchor block. A new technology is used to solve the above problems. The Chinese invention patent application with publication number CN 116815656A discloses a curved bonded prestressed carbon fiber cable reinforcement device and its construction process, including a carbon fiber cable, a fixed-end anchor assembly, a tensioning-end anchor assembly, a tensioning tool, a plurality of steering restraints and a jack for cable tensioning. Anchors are fixed at both ends of the carbon fiber cable. The fixed-end anchor assembly is used to consolidate with the component to facilitate mechanical conversion and realize automatic centering and leveling during the tensioning process. The tensioning-end anchor assembly is consolidated with the component and is used to install the tensioning tool to realize the application of prestress. The tensioning tool is used to realize reverse tensioning of the carbon fiber cable to apply prestress. The carbon fiber cable passes through a plurality of steering restraints. The steering restraint is used to adaptively adjust the angle of the carbon fiber cable within a specified range so that the angle transition of the carbon fiber cable is smooth and tightly fits and bonds to the surface of the component to be reinforced. The Chinese invention patent application with publication number CN113027165A discloses a lightweight external prestressed reinforcement system including two anchor units, at least one steel strand and a number of vibration-damping cable clamps. The two anchor units are respectively arranged at the two ends of the bottom surface of the bridge, and the vibration-damping cable clamps are evenly arranged on the bottom surface of the bridge between the anchor units, and the steel strand passes through the vibration-damping cable clamps. The processes used in the above two schemes are cumbersome, and still require anchors, clamps, tensioning devices and processes, resulting in problems such as difficulty in reinforcement construction. Therefore, there is an urgent need for a prestressed reinforcement device without anchors, clamps, and tensioning processes, which can meet the reinforcement requirements while achieving the requirements of short construction period, good quality, simple process, low carbon and environmental protection. Summary of the invention

[0003] An object of the present invention is to solve at least the above problems and to provide at least the advantages which will be described hereinafter.

[0004] In order to achieve these purposes and other advantages according to the present invention, a bridge anchorless prestressed reinforcement device is provided, comprising: A plurality of prestressed components, wherein the plurality of prestressed components are fixed to the bottom surface of the beam body at intervals through an adhesive layer; A stress dispersion layer fixedly covers both ends of the bottom surface of the beam body, and the stress dispersion layer is arranged between the bottom surface of the beam body and the end of the prestressed member; A heating device is used to heat each of the prestressed components.

[0005] Preferably, the stress dispersion layer is carbon fiber cloth, carbon fiber plate or FRP sheet.

[0006] Preferably, the adhesive layer is a thermal insulation adhesive, the thermal conductivity of the thermal insulation adhesive is less than 0.19w / (m•K), the tensile strength is not less than 5Mpa, and the compressive strength is not less than 30Mpa.

[0007] Preferably, the prestressed component is made of steel or fiber composite material.

[0008] Another object of the present invention is to provide a method for prestressing a bridge without anchorage, comprising the following steps: S1. Paste stress dispersion layers on both ends of the bottom surface of the beam; S2. Surface treatment is performed on the bottom surface of the beam where prestressed components are required; S3. Apply heat-insulating glue to the surface-treated parts; S4. Install each prestressed component and tighten it with a temporary fixing device; S5. Use a heating device to heat each prestressed component at the same time and keep it warm until the thermal insulation glue is cured.

[0009] Preferably, in step S1, the length of the stress dispersion layer is consistent with the width of the bottom surface of the beam body.

[0010] Preferably, the surface treatment method in step S2 is grinding or chiseling, and the surface treatment depth is not less than 5 mm.

[0011] Preferably, in step S5, the heating temperature is 50-500°C.

[0012] Preferably, in step S5, the heating temperature is 80-150°C.

[0013] The present invention has at least the following beneficial effects: 1. The anchor-free prestressed reinforcement device and reinforcement method for bridges provided by the present invention heat each prestressed component by a heating device, and utilize the deformation and elongation of the prestressed component after heating and the contraction after cooling to generate a high-strength tension force as prestress to resist the bending moment and tensile stress of the beam body, thereby reinforcing the beam body. During the reinforcement process, there is no need to wait for the age of concrete, and there are no complicated tensioning, anchoring and other processes, which greatly simplifies the process, equipment and materials of prestressed construction, effectively improves the construction efficiency and reduces the construction difficulty.

[0014] 2. The anchorless prestressed reinforcement device and reinforcement method for bridges provided by the present invention realize full bonding of the prestress on the reinforced beam, avoiding the problems of stress concentration existing in other external prestresses, easy damage of anchor blocks or turning blocks due to high forces, and great influence of construction on the reinforcement effect.

[0015] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a top view of the anchor-free prestressed reinforcement device for bridges of the present invention on the bottom surface of the beam body; Figure 2 It is a schematic diagram of the side structure of the anchor-free prestressed reinforcement device for bridges according to the present invention; Figure 3 It is a schematic diagram of the structure of the fixing device of the present invention. DETAILED DESCRIPTION

[0017] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0018] It should be noted that the experimental methods described in the following embodiments are conventional methods unless otherwise specified, and the reagents and materials are commercially available unless otherwise specified; in the description of the present invention, the terms "lateral", "longitudinal", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0019] like Figure 1 and Figure 2 As shown, the present invention provides a bridge anchorless prestressed reinforcement device, comprising: A plurality of prestressed components 3, wherein the plurality of prestressed components 3 are fixed to the bottom surface 2 of the beam body at intervals through an adhesive layer 4; A stress dispersion layer 1, which is fixedly covered on both ends of the bottom surface 2 of the beam body, and the stress dispersion layer 1 is arranged between the bottom surface 2 of the beam body and the end of the prestressed member 3; A heating device is used to heat each of the prestressed components 3.

[0020] In this technical solution, the heating device is used to heat each of the prestressed components 3. After heating, the prestressed components 3 will deform and elongate, and then be fixed to the bottom surface 2 of the beam body by the bonding layer 4. After the heating is stopped, the prestressed components 3 gradually cool down and shrink, thereby generating a high-strength tensioning force as a prestress to resist the bending moment and tensile stress of the beam body, thereby strengthening the beam body. The prestressed components 3 are fully bonded to the reinforced beam body through the bonding layer 4, and the prestress at both ends of the prestressed components 3 is further dispersed by the stress dispersion layer 1, effectively avoiding the stress concentration problem existing in other external prestressing. The above reinforcement process does not require waiting for the age of concrete, and there is no complicated tensioning, anchoring and other processes, which greatly simplifies the prestressing process, equipment and materials, and saves construction time and costs.

[0021] In another technical solution, the stress dispersion layer 1 is a carbon fiber cloth, a carbon fiber plate or a FRP sheet. Carbon fiber materials and FRP sheets can efficiently transfer and disperse local concentrated stress to a larger area through their high elastic modulus, high strength and other characteristics.

[0022] In another technical solution, the adhesive layer 4 is a heat-insulating adhesive, the thermal conductivity of the heat-insulating adhesive is less than 0.19w / (m•K), the tensile strength is not less than 5Mpa, and the compressive strength is not less than 30Mpa. Preferably, the heat-insulating adhesive can be a high-strength heat-insulating adhesive, such as polyurethane adhesive, epoxy resin adhesive, ceramic adhesive, silicone adhesive, inorganic high-temperature adhesive, etc.

[0023] In another technical solution, the prestressed component 3 is made of steel or fiber composite material. The high tensile strength, high elastic modulus and thermal expansion and contraction characteristics of steel or fiber composite material are utilized to generate prestress during the heating and cooling process to achieve reinforcement of the beam body. The prestressed component 3 can be in sheet or column shape.

[0024] The present invention also provides a method for reinforcing a bridge without anchorage prestressing, using the bridge without anchorage prestressing reinforcement device, comprising the following steps: S1, pasting stress dispersion layer 1 on both ends of the bottom surface 2 of the beam; S2. Surface treatment is performed on the part of the bottom surface 2 of the beam body where the prestressed member 3 needs to be arranged; S3. Apply heat-insulating glue to the surface-treated parts; S4, install each prestressed member 3 and press it with a temporary fixing device; S5. Use a heating device to heat each prestressed component 3 at the same time, and keep the temperature until the thermal insulation glue is solidified.

[0025] In step S1, the length of the stress dispersion layer 1 is consistent with the width of the beam bottom surface 2. Figure 1 As shown, the stress dispersion layer 1 should completely cover the end of the bottom surface 2 of the beam body and allow the end of the prestressed component 3 to overlap on it to ensure the stress dispersion effect.

[0026] The surface treatment method in step S2 is grinding or chiseling, and the surface treatment depth is not less than 5 mm. The surface treatment increases the bonding firmness of the bonding layer 4.

[0027] In step S3, the thermal insulation adhesive should fully cover the portion of the prestressed component 3 that contacts the bottom surface 2 of the beam body, so as to achieve full bonding of the prestressed component to the reinforced beam body.

[0028] In step S4, the prestressed component 3 cut according to the size of the beam is installed at the position coated with the thermal insulation glue, and is pressed by the temporary fixing device to prevent the prestressed component 3 from being separated from the glue. The temporary fixing device can be a fixing device that is easy to disassemble and commonly used in engineering, such as a tape, by which the prestressed component 3 is glued and fixed to the beam; or a temporary fixing device such as Figure 3 The fixing device is fixed. The fixing device includes: a support plate 51, with retractable legs 55 at both ends, a vacuum suction cup 54 at the bottom of the legs 55, and a vacuum suction cup 54 connected to a vacuum pumping device through a pipeline; the support plate 51 spans across each of the prestressed components 3, and a pressing plate 53 is provided corresponding to each of the prestressed components 3, and an elastic member 53 is provided between the pressing plate 53 and the support plate 51. First, the length of the legs 55 is set to match the thickness of the prestressed component 3, and after aligning each of the pressing plates 53 with each of the prestressed components 3, the vacuum pumping device is turned on to make each suction cup adsorbed on the beam body. During this process, each elastic member 52 is compressed, and then each of the prestressed components 3 is fixed through each of the pressing plates 53. In actual use, industrial suction cups and vacuum systems that meet the adsorption of concrete structures can be selected. And multiple groups of the fixing devices are set according to the length of the prestressed components. After the heat-insulating adhesive is fixed, first adjust the length of the legs on both sides of the support plate so that the rebound force of each elastic member is slowly released, and then release the adsorption of the suction cup.

[0029] In step S5, the heating temperature is 50-500°C. Furthermore, the heating temperature is 80-150°C. The heating device is sufficient to cause the prestressed component 3 to deform and elongate due to heat. The specific heating method can be selected from the commonly used methods in engineering construction, such as arc heating, resistance heating, high-frequency induction heating, electric heating, furnace heating, laser heating, etc., which are not limited here. When electric heating is adopted, the prestressed component 3 should be insulated, such as coating with insulating glue, wrapping with insulating materials, etc. During the heating process, before the thermal insulation glue is cured, the vertical displacement of the prestressed component 3 is limited by the temporary fixing device, but its deformation and elongation after heating are not limited. After the thermal insulation glue is cured, the deformed and elongated prestressed component 3 is fixed, so that the cooled prestressed component 3 provides tension to the beam to be reinforced.

[0030] In a bridge reinforcement project, Q460 steel plates with a cross-section of 5mm*100mm were used as prestressed components. A heating device was used to heat the prestressed components. After heating to 120°C, the components were kept warm until the thermal insulation adhesive was cured. The reinforcement effect was compared with the conventional reinforcement method using prestressed tendon tensioning as shown in Table 1 below.

[0031] Table 1 Comparison of reinforcement implementation effects As shown in Table 1, the tensioning force provided by two 5mm*100mm Q460 steel plates using the reinforcement method of the present invention is equivalent to the tensioning force provided by one φ14mm 1860 high-strength prestressed tendon in the conventional prestressed tendon tensioning reinforcement method. Compared with conventional prestressed tendon reinforcement, the reinforcement method provided by the present invention does not require a large anchoring device, avoids the tedious on-site construction such as mixed drilling, planting tendons, supporting formwork, installing prestressed tendons and prestressing, concrete pouring, etc., greatly improving the construction efficiency and reducing the construction difficulty.

[0032] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A bridge anchorless prestressed reinforcement device, characterized in that: include: A plurality of prestressed components, wherein the plurality of prestressed components are fixed to the bottom surface of the beam body at intervals through an adhesive layer; A stress dispersion layer fixedly covers both ends of the bottom surface of the beam body, and the stress dispersion layer is arranged between the bottom surface of the beam body and the end of the prestressed member; A heating device is used to heat each of the prestressed components.

2. The anchor-free prestressed reinforcement device for bridges according to claim 1, characterized in that: The stress dispersion layer is carbon fiber cloth, carbon fiber plate or FRP sheet.

3. The anchor-free prestressed reinforcement device for bridges according to claim 1, characterized in that: The adhesive layer is a heat-insulating adhesive, the thermal conductivity of the heat-insulating adhesive is less than 0.19w / (m•K), the tensile strength is not less than 5Mpa, and the compressive strength is not less than 30Mpa.

4. The anchor-free prestressed reinforcement device for bridges according to claim 1, characterized in that: The prestressed component is made of steel or fiber composite material.

5. A method for reinforcing a bridge without anchorage prestressing, using the bridge without anchorage prestressing reinforcement device as claimed in claim 3, characterized in that: The following steps are involved: S1. Paste stress dispersion layers on both ends of the bottom surface of the beam; S2. Surface treatment is performed on the bottom surface of the beam where prestressed components are required; S3. Apply heat-insulating glue to the surface-treated parts; S4. Install each prestressed component and tighten it with a temporary fixing device; S5. Use a heating device to heat each prestressed component at the same time and keep it warm until the thermal insulation glue is cured.

6. The anchor-free prestressed reinforcement method for a bridge according to claim 5, characterized in that: In step S1, the length of the stress dispersion layer is consistent with the width of the bottom surface of the beam body.

7. The anchorless prestressed reinforcement method for a bridge according to claim 5, characterized in that: In step S2, the surface treatment method is grinding or chiseling, and the surface treatment depth is not less than 5 mm.

8. The anchor-free prestressed reinforcement method for a bridge according to claim 7, characterized in that: In step S5, the heating temperature is 50-500°C.

9. The anchor-free prestressed reinforcement method for a bridge according to claim 8, characterized in that: In step S5, the heating temperature is 80-150°C.

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