Concrete inner sleeve type FRP rib anchoring device

Abstract

The invention discloses a sleeve type FRP rib anchoring device in concrete. The sleeve type FRP rib anchoring device comprises a hollow sleeve body, a positioning support and an auxiliary supporting frame. The hollow sleeve body is a hollow cylinder with through holes formed in the two ends, rubber gaskets are installed at the through holes in the two ends of the hollow sleeve body, a positioning support used for supporting the hollow sleeve body is installed at the tail of the hollow sleeve body, and the hollow sleeve body is provided with an auxiliary supporting frame. According to the invention, the characteristics of low elastic modulus, weak bending and shearing resistance and weak adhesive property of the FRP rib material are fully considered; the design of the annular ribs obviously enhances the bonding performance of the sleeve main body and concrete; the stress concentration at the end part is effectively relieved by the rubber gasket; the accurate positioning of the rib material is ensured by the positioning bracket; the auxiliary supporting structure is reasonable in design, and the initial deformation problem in the rib material mounting process is avoided; and the anchoring effect of the FRP rib and the concrete can be effectively enhanced in a limited anchoring space.

Description

Technical Field

[0001] The invention relates to the technical field of civil engineering, in particular to a concrete inner sleeve type FRP tendon anchoring device. Background Art

[0002] Lightweight, high-strength, corrosion-resistant, and fatigue-resistant fiber-reinforced composites (FRP) are ideal materials for achieving long life, lightweight, high performance, and low cost throughout the life cycle of building structures. Applying FRP to the field of construction engineering is an inevitable trend in the development of civil engineering disciplines and industries, and is an inherent requirement for achieving the transformation and upgrading of the construction industry and building resilient cities.

[0003] FRP bars are a composite material made of resin as the matrix and high-performance fiber as the reinforcement material through pultrusion process. They have attracted widespread attention due to their advantages such as low density, corrosion resistance, high tensile strength and non-magnetic properties. However, FRP bars based on thermosetting resins cannot be bent or folded on site, making it difficult to achieve good anchoring in concrete, especially carbon fiber reinforced composite (CFRP) bars with a tensile strength of up to 2500MPa. Therefore, the development of convenient and practical FRP bar anchoring devices is an inevitable requirement for promoting the development and application of FRP bar concrete structures.

[0004] The grouting sleeve with high-strength grouting material is a typical enhanced anchoring method, but existing studies have shown that the sleeve form suitable for traditional steel bars usually cannot directly meet the needs of FRP reinforced concrete structures, and it is very easy to lose the anchor. In addition, due to the low stiffness of FRP reinforcement materials, the gravity of the end grouting sleeve can easily cause the FRP reinforcement to produce initial deformation during the construction stage, affecting its performance. For this reason, the present invention proposes a concrete sleeve type FRP reinforcement anchoring device, which aims to solve the problem of anchoring FRP reinforcement in concrete structures and improve its overall performance and reliability. Summary of the invention

[0005] The purpose of the present invention is to provide a concrete inner sleeve type FRP tendon anchoring device to solve the problems in the prior art.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a sleeve-type FRP tendon anchoring device in concrete, comprising a hollow sleeve body, a positioning bracket and an auxiliary support frame; the hollow sleeve body is a hollow cylinder with through holes at both ends, rubber washers are installed at the through holes at both ends of the hollow sleeve body, a positioning bracket for supporting the hollow sleeve body is installed at the tail of the hollow sleeve body, the hollow sleeve body is provided with an auxiliary support frame, and the rubber washer is used to isolate the FRP tendon from direct contact with the sleeve and alleviate the problem of stress concentration at the end; a positioning bracket is provided at the tail of the sleeve body to ensure the precise positioning of the FRP tendon, and an auxiliary support is provided at the head to support the gravity of the sleeve body and avoid initial bending deformation of the FRP tendon due to its own weight.

[0007] Preferably, a grouting port and a grouting outlet are provided at the top of the hollow sleeve body, and grouting material is poured into the hollow sleeve body after the FRP bars are installed to enhance the internal anchoring performance of the sleeve.

[0008] Preferably, a plurality of annular ribs are installed on the inner surface and the outer surface of the hollow sleeve body to enhance the bonding performance between the sleeve and concrete.

[0009] Preferably, the spacing between adjacent annular ribs is 30-50 mm.

[0010] Preferably, when the rubber gasket is installed at the through hole of the hollow sleeve body, the outer diameter of the rubber gasket matches the inner diameter of the through hole of the hollow sleeve body, and the inner diameter of the rubber gasket matches the outer diameter of the FRP rib.

[0011] Preferably, the positioning bracket includes a steel frame grid and an annular protrusion, and the positioning bracket is equipped with multiple annular protrusions corresponding one-to-one to the hollow sleeve body. The annular protrusion is inserted into the tail of the hollow sleeve body to achieve precise positioning of the reinforcement, while ensuring that the bracket structure does not directly contact the FRP reinforcement to avoid affecting the reinforcement.

[0012] Preferably, the auxiliary support frame is composed of a connecting rod and an arc-shaped clamp, and arc-shaped clamps are installed at both ends of the connecting rod. The two arc-shaped clamps support two upper and lower adjacent hollow sleeve bodies. The auxiliary support frame connects the two adjacent upper and lower sleeves during the construction process, and together with the positioning bracket, it bears the gravity of the sleeve body to avoid initial bending deformation of the FRP reinforcement.

[0013] Preferably, the shape of the arc clamp is a 250° arc, and the auxiliary support is only connected to the sleeve body and can be removed during concrete pouring.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1. The characteristics of FRP bars with low elastic modulus, weak bending and shearing resistance, and weak bonding performance are fully considered; the annular rib design significantly enhances the bonding performance between the sleeve body and the concrete; the rubber gasket effectively alleviates the stress concentration at the end; the positioning bracket ensures the precise positioning of the bars; the auxiliary support structure is reasonably designed to avoid the initial deformation problem during the installation of the bars; this device can effectively enhance the anchoring effect of FRP bars and concrete in a limited anchoring space.

[0016] 2. While improving the anchoring performance of FRP bars, it significantly alleviates the anchoring problems caused by stress concentration and insufficient bonding; the optimized annular rib design enhances the bonding performance between the sleeve and concrete, and the grouting port design improves the safety and reliability of anchoring; the use of positioning brackets and auxiliary supports ensures the precise positioning and stability of the bars during installation and construction. This device is suitable for the anchoring needs of concrete components with FRP longitudinal bars in the diameter range of 10-20mm. It is not only suitable for scientific research experiments related to FRP bars, but can also be widely used in engineering practice, providing an important anchoring solution for the application of FRP bar concrete structure engineering. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0018] Figure 1 It is a schematic diagram of the structure of the present invention;

[0019] Figure 2 It is a cross-sectional view of the hollow sleeve body of the present invention after the FRP ribs are installed;

[0020] Figure 3 It is a structural schematic diagram of the positioning bracket of the present invention;

[0021] Figure 4 It is a structural schematic diagram of the hollow sleeve body and the auxiliary support frame of the present invention;

[0022] Figure 5 It is a structural schematic diagram of the auxiliary support frame of the present invention.

[0023] In the figure: 1. FRP reinforcement; 2. hollow sleeve body; 3. positioning bracket; 4. auxiliary support frame; 5. rubber gasket; 6. grouting port; 7. grouting outlet; 8. annular rib; 31. steel frame grid; 32. annular protrusion; 41. connecting rod; 42. arc clamp. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention.

[0025] See also Figure 1-2 In an embodiment of the present invention, a concrete inner sleeve type FRP bar anchoring device comprises a hollow sleeve body 2, a positioning bracket 3 and an auxiliary support frame 4; the hollow sleeve body 2 is a hollow cylinder with through holes at both ends, and rubber washers 5 are installed at the through holes at both ends of the hollow sleeve body 2. The rubber washers 5 are made of high-strength elastic rubber and are respectively located at both ends of the sleeve body 2 to isolate the FRP bar from contact with the sleeve body to alleviate the influence of end stress concentration during lateral deformation; when the rubber washers 5 are installed at the through holes of the hollow sleeve body 2, the outer diameter of the rubber washers 5 matches the inner diameter of the through holes of the hollow sleeve body 2. The inner diameter of the rubber gasket 5 matches the outer diameter of the FRP bar 1 to ensure the sealing of the device and avoid slurry leakage; a positioning bracket 3 for supporting the hollow sleeve body 2 is installed at the tail of the hollow sleeve body 2, and the hollow sleeve body 2 is provided with an auxiliary support frame 4. A grouting port 6 and a slurry outlet 7 are opened on the top of the hollow sleeve body 2. After the FRP bar 1 is installed, the hollow sleeve body 2 is poured with grouting material. A plurality of annular ribs 8 are installed on the inner and outer surfaces of the hollow sleeve body 2, and the spacing between adjacent annular ribs 8 is 30-50mm, which is used to enhance the bonding performance between the sleeve and concrete.

[0026] like Figure 2 and 3 The positioning bracket 3 includes a steel frame grid 31 and an annular protrusion 32. The positioning bracket 3 is equipped with multiple annular protrusions 32 corresponding to the hollow sleeve body 2. The annular protrusions 32 are inserted into the tail of the hollow sleeve body 2 to achieve accurate positioning of the FRP reinforcement. The annular protrusions of the positioning bracket 3 are only connected to the sleeve body 2 and are not in direct contact with the FRP reinforcement.

[0027] like Figure 4 and 5The auxiliary support frame 4 is composed of a connecting rod 41 and an arc clamp 42. The two ends of the connecting rod 41 are installed with arc clamps 42. The two arc clamps 42 support the two upper and lower adjacent hollow sleeve bodies 2. The auxiliary support frame 4 connects the upper and lower adjacent sleeves during the construction process, and jointly bears the gravity of the sleeve body 2 with the positioning bracket 3 to avoid initial bending deformation of the FRP reinforcement. The shape of the arc clamp 42 is a 250° arc. The auxiliary support 4 is only connected to the sleeve body 2 and can be removed during concrete pouring.

[0028] The working principle of the present invention is: during use, first assemble the rubber gasket 5 at both ends of the sleeve body 2 and ensure that the size fits well; then pass the FRP bar 1 through the sleeve body 2 and the rubber gasket 5, and ensure that the tail FRP bar does not extend out of the rubber gasket 5. After all the FRP bars 1 and the sleeve body 2 are assembled one by one, the positioning bracket 3 is used to achieve accurate positioning of all the bars, and the auxiliary support 4 is used to stabilize the adjacent sleeves; then high-strength grouting material is poured through the grouting port 6 to fill the inside of the sleeve body 2, and the installation of the anchoring device can be completed after the grouting material hardens; according to the structural use scenario and force requirements, the auxiliary support 4 can be removed before pouring concrete.

[0029] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A concrete sleeve type FRP bar anchoring device, characterized in that: It comprises a hollow sleeve body (2), a positioning bracket (3) and an auxiliary support frame (4); The hollow sleeve body (2) is a hollow cylinder with through holes at both ends. Rubber gaskets (5) are installed at the through holes at both ends of the hollow sleeve body (2). A positioning bracket (3) for supporting the hollow sleeve body (2) is installed at the tail of the hollow sleeve body (2). The hollow sleeve body (2) is provided with an auxiliary support frame (4).

2. A concrete sleeve type FRP tendon anchoring device according to claim 1, characterized in that: The top of the hollow sleeve body (2) is provided with a grouting port (6) and a grouting outlet (7), and the hollow sleeve body (2) is filled with grouting material after the FRP bars (1) are installed.

3. The concrete sleeve type FRP tendon anchoring device according to claim 1, characterized in that: A plurality of annular ribs (8) are installed on the inner surface and the outer surface of the hollow sleeve body (2).

4. A concrete sleeve type FRP tendon anchoring device according to claim 3, characterized in that: The distance between adjacent annular ribs (8) is 30-50 mm.

5. The concrete sleeve type FRP tendon anchoring device according to claim 1, characterized in that: When the rubber gasket (5) is installed at the through hole of the hollow sleeve body (2), the outer diameter of the rubber gasket (5) matches the inner diameter of the through hole of the hollow sleeve body (2), and the inner diameter of the rubber gasket (5) matches the outer diameter of the FRP rib (1).

6. The concrete sleeve type FRP tendon anchoring device according to claim 1, characterized in that: The positioning bracket (3) comprises a steel frame grid (31) and an annular protrusion (32). The positioning bracket (3) is provided with a plurality of annular protrusions (32) corresponding one to one with the hollow sleeve body (2). The annular protrusions (32) are inserted into the tail of the hollow sleeve body (2).

7. The concrete sleeve type FRP tendon anchoring device according to claim 1, characterized in that: The auxiliary support frame (4) is composed of a connecting rod (41) and an arc-shaped clamp (42). The two ends of the connecting rod (41) are both installed with an arc-shaped clamp (42). The two arc-shaped clamps (42) support two upper and lower adjacent hollow sleeve bodies (2).

8. The concrete sleeve type FRP tendon anchoring device according to claim 7, characterized in that: The shape of the arc-shaped clamp (42) is a 250° arc.

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