Integral split-type anchor with CFRP tendon based on variable width through slit and installation method

Abstract

The application discloses a CFRP bar integral type wedge anchor based on a variable-width through slit and a mounting method, and relates to the technical field of civil engineering cable structures. The integral type wedge anchor comprises an anchor ring, a variable-section cylindrical through hole is arranged on the inner side of the anchor ring, and an integral type wedge is arranged in the variable-section cylindrical through hole in the anchor ring. The integral type wedge is a variable-section cylinder, the outer side inclination angle of the integral type wedge is larger than the inclination angle of the variable-section cylindrical through hole in the anchor ring, a cylindrical through hole for inserting a CFRP bar is arranged in the integral type wedge, a variable-width through slit and an equal-width non-through slit are arranged in the axial direction of the integral type wedge, and the end of the variable-width through slit with a relatively narrow width is connected to the cylindrical through hole. The application solves the problems that the CFRP bar of the integral type wedge anchor is suddenly pulled out under high stress and cannot be standardized, and improves the stability of the application of the CFRP bar integral type wedge anchor.

Description

Technical Field

[0001] This invention belongs to the technical field of cable-stayed structures in civil engineering, specifically relating to an integral wedge-type anchorage for CFRP reinforcement based on a variable-width through joint and its installation method. Background Technology

[0002] Carbon fiber reinforced polymer (CFRP) possesses excellent mechanical, physical, and chemical properties, including lightweight, high strength, corrosion resistance, fatigue resistance, and low-temperature deformation, making it widely considered an ideal material for cable-stayed structures. Currently, CFRP cables are used in cable-stayed roof structures; however, the typical orthotropic mechanical properties of CFRP cables make efficient anchoring difficult, hindering their widespread application.

[0003] To address the challenges of anchoring CFRP bars, including difficulty, low efficiency, and poor stability, researchers developed an integral wedge anchor. This type of anchor is small, lightweight, and easy to install, overcoming the problem of asynchronous wedge displacement in separate wedge anchors and achieving efficient anchoring of CFRP bars. However, the integral wedge anchor has two potential drawbacks in application: First, poor anchoring stability. In static tensile tests, the integral wedge anchor system exhibits a failure mode where the CFRP bar is suddenly pulled out under high stress. This is because the deformation capacity of the integral wedge is affected by the width of its through-slot. An excessively wide slot can damage the CFRP bar at the slot edge, while an excessively narrow slot can cause it to close, resulting in the wedge losing its clamping force and ultimately pulling the bar out. Determining the appropriate slot width is difficult, leading to poor anchor stability in application. Second, the appropriate slot width varies for CFRP bars of different diameters, making standardized design impossible and reducing its economic viability. Summary of the Invention

[0004] This invention proposes an integral wedge anchor based on a through-slit variable width design. By designing the width of the integral wedge on both sides of the through-slit, it avoids damage to the CFRP reinforcement from the edge of the gap, while ensuring that the wedge has sufficient deformation capacity to prevent it from losing its clamping force. This solves the problem of CFRP reinforcement being suddenly pulled out under high stress and the problem of non-standardization in integral wedge anchors for CFRP reinforcement, improves the stability of the application of integral wedge anchors for CFRP reinforcement, and promotes the use of CFRP reinforcement in cable structures in civil engineering.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] The CFRP reinforcement monolithic wedge type anchor based on variable width through joint includes:

[0007] Anchor ring, wherein the inner side of the anchor ring is provided with a variable cross-section cylindrical through hole;

[0008] An integral clamp is inserted into a variable cross-section cylindrical through hole inside the anchor ring. The integral clamp is a variable cross-section cylinder. The outer inclination angle of the integral clamp is greater than the inclination angle of the variable cross-section cylindrical through hole inside the anchor ring. The integral clamp has a cylindrical through hole inside for inserting CFRP bars. The integral clamp has a variable width through slot and a constant width non-through slot in the axial direction. The narrower end of the variable width through slot is connected to the cylindrical through hole.

[0009] Preferably, the width of the inner gap of the variable-width through-slit is 0.6-1.2 mm, and the width of the outer gap is 2-4 mm; the width of the equal-width non-through-slit is 1 mm.

[0010] Preferably, the inner gap width of the variable-width through-slit is 0.9 mm, and the outer gap width is 3 mm; the width of the equal-width non-through-slit is 1 mm.

[0011] Preferably, the inclination angle of the variable cross-section cylindrical through hole is in the range of 3°-4°, and the outer inclination angle of the integral clamp is in the range of 3°-4°; the angle difference between the inclination angle of the variable cross-section cylindrical through hole and the outer inclination angle of the integral clamp is in the range of 0.1°-0.3°.

[0012] Preferably, the inclination angle of the variable cross-section cylindrical through hole is 3°, and the outer inclination angle of the integral clip is 3.2°.

[0013] Preferably, one variable-width through-slit is provided, and two or three equal-width non-through-slits are provided.

[0014] Preferably, the cylindrical through hole has a raised thread at the tail.

[0015] The installation method of the CFRP reinforcement integral wedge type anchor based on the variable width through joint includes the following steps:

[0016] S1. Apply a thin layer of fast-curing epoxy resin adhesive to the reinforcement anchorage area;

[0017] S2. Insert the CFRP rib into the cylindrical through hole of the integral clamp;

[0018] S3. Finally, apply a preload of 120kN to insert the integral wedge into the variable cross-section cylindrical through hole of the anchor ring.

[0019] Preferably, the integral wedge-type anchor can be used for CFRP bars with a diameter of 3mm-20mm.

[0020] The beneficial effects of this invention are:

[0021] This invention proposes an integral wedge anchor based on a variable-width through-slot design. By setting the through-slot of the integral wedge as a variable-width gap, the CFRP reinforcement is prevented from being squeezed and damaged by the gap edge, ensuring that the integral wedge has sufficient deformation capacity to prevent it from losing its clamping force. This solves the problem of CFRP reinforcement being suddenly pulled out under high stress and the problem of non-standardization in integral wedge anchors for CFRP reinforcement, improves the stability of the application of integral wedge anchors for CFRP reinforcement, and promotes the use of CFRP reinforcement in cable structures in civil engineering. Attached Figure Description

[0022] For ease of explanation, the present invention will be described in detail below with reference to specific embodiments and accompanying drawings.

[0023] Figure 1 This is a schematic diagram of the assembly of the integral clamping plate and anchor ring in this embodiment;

[0024] Figure 2 This is a schematic diagram of the integral clip structure in this embodiment;

[0025] Figure 3 This is a side view of the integral clip in this embodiment.

[0026] In the picture:

[0027] 100 - Anchor ring; 110 - Variable cross-section cylindrical through hole;

[0028] 200 - Integral clamping piece; 210 - Cylindrical through hole; 220 - Variable width through joint; 230 - Equal width non-through joint. Detailed Implementation

[0029] The following are specific embodiments of the present invention described in conjunction with the accompanying drawings, further illustrating the technical solutions of the present invention. However, the present invention is not limited to these embodiments. Specific details, such as particular configurations and components, are provided in the following description merely to aid in a comprehensive understanding of the embodiments of the present invention. Therefore, those skilled in the art should understand that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present invention. Furthermore, for clarity and brevity, descriptions of known functions and structures have been omitted.

[0030] It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other.

[0031] Example 1

[0032] like Figures 1-3As shown, the CFRP reinforcement integral wedge type anchor based on variable width through joint provided in this embodiment includes: an anchor ring 100 and an integral wedge 200. The anchor ring 100 is made of steel, and its outer contour is a cylinder of equal diameter. The inner side of the anchor ring 100 has a variable cross-section cylindrical through hole 110. The integral wedge 200 is made of aluminum and is inserted into the variable cross-section cylindrical through hole 110 inside the anchor ring 100. The integral wedge 200 is a variable cross-section cylinder, and its outer inclination angle is greater than the inclination angle of the variable cross-section cylindrical through hole 110 inside the anchor ring 100. The inclination angle of the variable cross-section cylindrical through hole 110 ranges from 3° to 4°. The outer inclination angle of 0 is 3°-4°, and the angle difference between the inclination angle of the variable cross-section cylindrical through hole 110 and the outer inclination angle of the integral clamp 200 is 0.1°-0.3°. The integral clamp 200 has a cylindrical through hole 210 for inserting CFRP bars inside, and the tail of the cylindrical through hole 210 has a raised thread. The integral clamp 200 has one variable width through slot 220 and two equal width non-through slots 230 in the axial direction. The narrower end of the variable width through slot 220 is connected to the cylindrical through hole 210. The width of the gap inside the variable width through slot 220 is 0.6-1.2mm, and the width of the gap outside is 2-4mm. The width of the equal width non-through slot 230 is 1mm.

[0033] The installation method for CFRP reinforcement monolithic wedge-type anchors based on variable width through joints includes the following steps:

[0034] S1. Apply a thin layer of fast-curing epoxy resin adhesive to the reinforcement anchorage area;

[0035] S2. Insert the CFRP rib into the cylindrical through hole 210 of the integral clamp 200;

[0036] S3. Finally, apply a preload of 120kN to send the integral clamp 200 into the variable cross-section cylindrical through hole 110 of the anchor ring 100.

[0037] The integral wedge-type anchorage of this embodiment can be used for CFRP bars with a diameter of 3mm-20mm. The installation method is simple, easy to operate, and improves construction efficiency.

[0038] In this embodiment, the numerical range of the inclination angle of the variable cross-section cylindrical through hole 110 and the outer inclination angle of the integral clamp 200 was obtained through numerical simulation test. The angle and the preload are coordinated with each other. When the angle is large, the preload is small and when the angle is small, the preload is large. If the preload is small, the integral clamp will move after the reinforcement is stretched. The more it moves, the less stable it becomes. In this embodiment, the numerical range of the inclination angle of the variable cross-section cylindrical through hole and the outer inclination angle of the integral clamp, combined with the preload, makes the anchorage more stable and the anchorage performance more reliable.

[0039] In this embodiment, the through-slot of the integral wrench adopts a variable width design. The side of the variable width through-slot 220 that contacts the CFRP bar has a smaller gap width to ensure that the gap edge does not squeeze the CFRP bar, while the side of the variable width through-slot 220 that contacts the anchor ring 100 has a larger gap width to ensure that the gap does not close during deformation of the wrench. The variable width design of the through-slot solves the problem of poor stability of the integral wrench anchor in application. At the same time, this design also solves the design problem that different diameter CFRP bars need to correspond to different width through-slots, realizing the standardized design of the integral wrench anchor, which can be applied to clamping CFRP bars with diameters from 3mm to 20mm.

[0040] Example 2

[0041] The difference between this embodiment and Embodiment 1 is that the inner gap width of the variable width through-slit 220 is 0.9mm, the outer gap width is 3mm, and the width of the equal width non-through-slit 230 is 1mm; the inclination angle of the variable cross-section cylindrical through-hole 110 is 3°, and the outer inclination angle of the integral clamp 200 is 3.2°.

[0042] The inclination angles of the variable cross-section cylindrical through-hole 110 and the outer inclination angle of the integral clamp 200 in this embodiment are optimal values ​​obtained through numerical simulation experiments. The angles and preload work together to make the anchoring force more stable and larger, resulting in more reliable anchoring performance. The width values ​​of the gaps on the inner and outer sides of the variable width through-slit 220 are also optimal values ​​obtained through numerical simulation experiments.

[0043] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0044] In the description of this application, it should be understood that the terms "upper" and "lower" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0045] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0046] Those skilled in the art to which this application pertains may make various modifications or additions to the specific embodiments described, or adopt similar methods to replace them, without departing from the spirit of this application or exceeding the scope defined by the appended claims.

Claims

1. A CFRP reinforcement integral wedge-type anchor based on a variable-width through-slot, characterized in that, include: Anchor ring (100), wherein the inner side of the anchor ring (100) is provided with a variable cross-section cylindrical through hole (110); An integral clamping piece (200) is inserted into a variable cross-section cylindrical through hole (110) inside an anchor ring (100). The integral clamping piece (200) is a variable cross-section cylinder. The outer inclination angle of the integral clamping piece (200) is greater than the inclination angle of the variable cross-section cylindrical through hole (110) inside the anchor ring. The integral clamping piece (200) is provided with a cylindrical through hole (210) for inserting CFRP bars. The integral clamping piece (200) is provided with a variable width through slot (220) and a constant width non-through slot (230) in the axial direction. The narrower end of the variable width through slot (220) is connected to the cylindrical through hole (210). The width of the inner gap of the variable-width through joint (220) ranges from 0.6 to 1.2 mm, and the width of the outer gap ranges from 2 to 4 mm; the width of the equal-width non-through joint (230) is 1 mm. The inclination angle of the variable cross-section cylindrical through hole (110) is in the range of 3°-4°, and the outer inclination angle of the integral clamp (200) is in the range of 3°-4°; the angle difference between the inclination angle of the variable cross-section cylindrical through hole (110) and the outer inclination angle of the integral clamp (200) is in the range of 0.1°-0.3°.

2. The integral wedge-type anchorage of CFRP reinforcement based on variable width through joint as described in claim 1, characterized in that, The inner gap width of the variable width through-slit (220) is 0.9 mm, and the outer gap width is 3 mm.

3. The integral wedge-type anchorage of CFRP reinforcement based on variable width through joint as described in claim 1, characterized in that, The inclination angle of the variable cross-section cylindrical through hole (110) is 3°, and the outer inclination angle of the integral clip (200) is 3.2°.

4. The integral wedge-type anchorage of CFRP reinforcement based on variable width through joint as described in claim 1, characterized in that, One variable-width through joint (220) is provided, and two or three equal-width non-through joints (230) are provided.

5. The integral wedge-type anchorage of CFRP reinforcement based on variable width through joint as described in claim 1, characterized in that, The cylindrical through hole (210) has a raised thread at the tail.

6. The installation method of the integral wedge-type anchorage of CFRP reinforcement based on variable width through joint as described in claim 1, characterized in that, The installation method steps are as follows: S1. Apply a thin layer of fast-curing epoxy resin adhesive to the reinforcement anchorage area; S2. Insert the CFRP rib into the cylindrical through hole (210) of the integral clamp; S3. Finally, apply a preload of 120kN to send the integral clamp (200) into the variable cross-section cylindrical through hole (110) of the anchor ring (100).

7. The installation method of the integral wedge-type anchorage of CFRP reinforcement based on variable width through joint as described in claim 6, characterized in that, The integral wedge-type anchor can be used for CFRP bars with a diameter of 3mm-20mm.

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