Embedded hybrid fiber thread rib and manufacturing method thereof

Abstract

The invention provides an embedded hybrid fiber threaded rib and a manufacturing method thereof.The embedded hybrid fiber threaded rib comprises a core axial fiber bundle, a surface layer structure fiber bundle formed through curing is arranged on the outer side of the core axial fiber bundle, at least one spiral indentation groove is formed in the outer side of the surface layer structure fiber bundle, and the surface layer structure fiber bundle is arranged in the indentation groove. A spiral additional rib fiber bundle is fixedly arranged in the indentation groove along the indentation groove; according to the embedded hybrid fiber threaded rib, a hybrid fiber scheme is adopted, according to performance requirements, the core axial fiber bundles, the surface layer structure fiber bundles, the indentation grooves and other components in the rib material adopt different fiber types, the performance characteristics of different fibers are fully exerted, and the comprehensive performance of the rib material is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of FRP bars and specifically relates to an embedded hybrid fiber threaded bar and a manufacturing method thereof. Background Art

[0002] Carbon fiber composite material (CFRP) has excellent properties such as light weight, high strength, corrosion resistance, and fatigue resistance. It is a new type of high-performance structural material. It can reduce the weight of the structure and improve the performance and durability of the structure when used in civil engineering structures. It has a good application prospect. In the form of ribbed bars, carbon fiber bars can replace steel bars and be used in concrete structures and anchor rods.

[0003] Carbon fiber reinforcement is usually produced by pultrusion process. The production of high-performance ribbed reinforcement still faces certain challenges. The main ribbed reinforcement processing forms are as follows:

[0004] 1) Indented ribs: Before the fiber and the resin matrix pass through the mold, a release cloth is wrapped around them, and after curing and molding, the release cloth is peeled off to form a threaded indentation, such as a Chinese invention patent application with application publication number CN111945718A, which discloses a high-performance, corrosion-resistant, embossed FRP anchor and its preparation method;

[0005] 2) Curing threaded ribs after extrusion: After the fiber and resin matrix are preformed, additional fibers are wound around them, and spiral grooves are formed on the surface by tightening them. The threads are then cured by heating in an oven, and finally the additional fibers are removed to form spiral grooves.

[0006] 3) Mechanically cut threaded ribs: After the fiber and the resin matrix are solidified and formed by a high-temperature mold, threaded indentations are formed by mechanical cutting. For example, the Chinese invention patent document with authorization announcement number CN103225369B discloses a fiber composite rib with a threaded structure on the surface and a preparation method thereof, which adopts a pultrusion process.

[0007] The above-mentioned indented bars and extruded cured threaded bars will directly change the surface fiber orientation, making it unfavorable to bear force, thus affecting the mechanical properties of the entire bar. At the same time, for bars with larger diameters, the depth of the threaded ribs formed by this method is limited, making it difficult to ensure the bonding force between the bar and the concrete. The surface fibers of the mechanically cut threaded bars are directly cut off, and the remaining fibers (ribs) are only used for construction and cannot directly participate in the force, thereby weakening the bar cross section. In addition, due to the anisotropy of the material, the existing carbon fiber threaded bars still have the problem of low shear strength.

[0008] In view of the above technical challenges and the limitations of existing carbon fiber threaded bars, in order to meet engineering applications, it is necessary to develop a new type of fiber-reinforced threaded bar that can improve performance, increase material utilization, and reduce production costs, so as to play a greater role in practical applications. Summary of the invention

[0009] In view of the deficiencies in the prior art, the present invention provides an embedded hybrid fiber threaded rib and a method for manufacturing the same, which can improve performance, increase material utilization, and reduce production costs, thereby playing a greater role in practical applications.

[0010] The technical solution of the present invention is: an embedded mixed fiber threaded rib, comprising a core axial fiber bundle, a cured surface structural fiber bundle is arranged on the outside of the core axial fiber bundle, at least one spiral indentation groove is arranged on the outside of the surface structural fiber bundle, and a spiral additional rib fiber bundle is fixedly arranged along the inside of the indentation groove.

[0011] Furthermore, the core axial fiber bundle is a carbon fiber bundle; the surface structural fiber bundle is a glass fiber bundle, a basalt fiber bundle or an aramid fiber bundle; and the additional rib fiber bundle is a carbon fiber bundle, a glass fiber bundle or a basalt fiber bundle.

[0012] Furthermore, the depth h0 of the indentation groove is 0.1-0.5 mm, the thickness t1 of the surface structural fiber bundle is 0.5-1 cmm, and the height hr of the additional rib fiber bundle protruding from the surface of the surface structural fiber bundle is 0.08-0.15 times the outer diameter d1 of the surface structural fiber bundle.

[0013] Furthermore, the cross-section of the additional rib fiber bundle is triangular, rectangular or trapezoidal.

[0014] The manufacturing method of the embedded hybrid fiber threaded rib comprises the following steps:

[0015] S1, after the core axial fiber bundle and the surface structural fiber bundle are impregnated with resin, they are preformed through a circular preforming mold to obtain a preformed circular rod;

[0016] S2, spirally wrapping a demoulding tape on the surface of the preformed round rod, and then passing through a round forming mold to obtain a round rod after curing;

[0017] S3, after the round bar is demolded, the demoulding tape is gradually removed to form a spiral indentation groove on the surface of the round bar;

[0018] S4, after the additional rib fiber bundle is impregnated with resin, it is wound and embedded in the spiral indentation groove, and the additional rib fiber bundle is protruded from the surface of the surface structural fiber bundle by a height of hr, and then cured in an oven.

[0019] Furthermore, in S2, at least two demoulding tapes are evenly and staggeredly wound on the surface of the preformed round rod;

[0020] In S3, after the round bar is demolded, the demoulding tape is gradually removed to form at least two uniformly staggered spiral indentation grooves on the surface of the round bar.

[0021] Furthermore, in S2, the angle θ between the demoulding tape and the preformed round rod support is 45° to 70°.

[0022] Further, the S1 can be replaced by: S11, after the core axial fiber bundle is impregnated with resin, it is cured and preformed through a circular first preforming mold with a hole diameter of d0 and a first forming mold to obtain a core fiber bundle circular rod;

[0023] S12, after the surface structural fiber bundle is impregnated with resin, it is distributed on the periphery of the core fiber bundle circular rod in S11, and is preformed on the outside of the core axial fiber bundle preformed in S11 through a second preforming mold with a hole diameter of d1 to obtain a preformed circular rod.

[0024] Furthermore, the S4 is replaced by: the additional rib fiber bundle is made of thermoplastic fiber composite material, the thermoplastic fiber composite material is softened by heating the mold, and is formed into the shape of the additional rib fiber bundle, and then is wrapped, bonded and embedded in the spiral indentation groove, and then naturally cooled and solidified.

[0025] Furthermore, the core axial fiber bundle is a carbon fiber bundle; the surface structural fiber bundle is a glass fiber bundle, a basalt fiber bundle or an aramid fiber bundle; and the additional rib fiber bundle is a carbon fiber bundle, a glass fiber bundle or a basalt fiber bundle.

[0026] Beneficial effects of the present invention:

[0027] (1) The embedded hybrid fiber threaded reinforcement in the present invention adopts a hybrid fiber solution. According to the performance requirements, the core axial fiber bundle, the surface structural fiber bundle, the indentation groove and other components in the reinforcement material adopt different fiber types to give full play to the performance characteristics of different fibers and improve the comprehensive performance of the reinforcement material;

[0028] (2) The core axial fiber bundle and the surface structural fiber bundle constitute the main body of the reinforcement material. The indentation groove only changes the orientation of the surface structural fiber bundle and does not affect the mechanical performance of the core axial fiber bundle;

[0029] (3) The additional rib fiber bundle is wrapped and embedded in the preformed indentation groove to form a mechanical bite with the surface structural fiber bundle, which can greatly improve the overall bonding force between the additional rib fiber bundle and the reinforcement surface, and prevent the additional rib fiber bundle from slipping, thereby improving the bonding performance between the threaded reinforcement and concrete;

[0030] (4) The additional rib fiber bundle is wound around the outside of the core axial fiber bundle and the surface structural fiber bundle, constraining the core axial fiber bundle and the surface structural fiber bundle. The additional rib fiber bundle always forms a certain angle with the longitudinal core axial fiber bundle and the surface structural fiber bundle, which can improve the transverse shear strength of the reinforcement.

[0031] (5) The main reinforcement body composed of the core axial fiber bundle and the surface structural fiber bundle is cured in the mold, which can effectively ensure the molding quality of the axial force fiber; the additional rib fiber bundle is bonded and cured through a post-curing process, allowing for flexible design of the cross-sectional shape of the additional rib;

[0032] (6) The core axial fiber bundle and the surface structural fiber bundle are formed in steps, which can prevent the core axial fiber bundle from generating radial deformation during the indentation groove forming process, thereby ensuring the orientation of the core axial fibers and giving full play to the tensile properties of the core fiber bundle. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the structure of the embedded hybrid fiber threaded reinforcement in the present invention.

[0034] Figure 2 It is a schematic diagram of the cross-sectional structure of the embedded hybrid fiber threaded reinforcement in the present invention.

[0035] Figure 3 It is a schematic diagram of the structure of the surface structure fiber bundle at the indentation groove in the present invention.

[0036] Figure 4 It is a schematic diagram of the cross-sectional structure of the embedded hybrid fiber threaded reinforcement in the present invention.

[0037] Figure 5 It is a schematic diagram of a manufacturing process of the embedded hybrid fiber threaded reinforcement in the present invention.

[0038] Figure 6 It is a schematic diagram of another manufacturing process of the embedded hybrid fiber threaded reinforcement in the present invention.

[0039] Figure 7 It is a schematic diagram of another manufacturing process of the embedded hybrid fiber threaded reinforcement in the present invention.

[0040] Figure 8 It is a schematic diagram of the structure of the double-threaded hybrid fiber threaded reinforcement in the present invention. DETAILED DESCRIPTION

[0041] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and is in no way intended to limit the present invention and its application or use. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the present invention thorough and complete and to fully express the scope of the present invention to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of the parts and steps, the composition of the materials, the numerical expressions and the numerical values ​​set forth in these embodiments should be interpreted as being merely exemplary, rather than as limitations.

[0042] The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different parts. The words "include" or "comprise" and similar words mean that the elements before the word include the elements listed after the word, and do not exclude the possibility of including other elements. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0043] like Figures 1 to 3 As shown, the embedded hybrid fiber threaded reinforcement comprises a core axial fiber bundle 1, a cured surface structural fiber bundle 2 is arranged on the outside of the core axial fiber bundle 1, at least one spiral indentation groove 3 is arranged on the outside of the surface structural fiber bundle 2, and a spiral additional rib fiber bundle 4 is fixedly arranged along the inside of the indentation groove 3; in this embodiment, a hybrid fiber scheme is adopted, and according to performance requirements, the core axial fiber bundle 1, the surface structural fiber bundle 2, the indentation groove 3 and other components in the reinforcement material adopt different fiber types to give full play to the performance characteristics of different fibers and improve the comprehensive performance of the reinforcement material; the core axial fiber bundle 1 and the surface structural fiber bundle 2 constitute the main body of the reinforcement material, and the indentation groove 3 only changes The orientation of the surface structural fiber bundle 2 does not affect the stress-bearing performance of the core axial fiber bundle 1; the additional rib fiber bundle 4 is wound and embedded in the preformed indentation groove 3, forming a mechanical bite with the surface structural fiber bundle 2, which can greatly improve the overall bonding force between the additional rib fiber bundle 4 and the surface of the reinforcement material, and can prevent the additional rib fiber bundle 4 from slipping, thereby improving the bonding performance between the threaded reinforcement and concrete; the additional rib fiber bundle 4 is wound around the outside of the core axial fiber bundle 1 and the surface structural fiber bundle 2, forming constraints on the core axial fiber bundle 1 and the surface structural fiber bundle 2, and the additional rib fiber bundle 4 always has a certain angle with the longitudinal core axial fiber bundle 1 and the surface structural fiber bundle 2, which can improve the transverse shear strength of the reinforcement material.

[0044] In some embodiments, as a specific implementation of the core axial fiber bundle 1, the core axial fiber bundle 1 is a carbon fiber bundle, the core axial fiber bundle 1 and the surface structural fiber bundle 2 constitute the reinforcement body, the indentation groove 3 only changes the orientation of the surface structural fiber bundle 2, and does not affect the stress-bearing performance of the core axial fiber bundle 1. The core axial fiber bundle 1 is made of high-performance carbon fiber, and the core axial fiber bundle 1, as the main axial force-bearing part, can give full play to the high performance of carbon fiber.

[0045] In some embodiments, as a specific implementation of the surface structural fiber bundle 2, the surface structural fiber bundle 2 is a glass fiber bundle, a basalt fiber bundle or an aramid fiber bundle; on the one hand, the glass fiber bundle, basalt fiber bundle or aramid fiber bundle and other such fiber carbon fiber have low modulus, high elongation, good wear resistance, good impact resistance and other characteristics, which can improve the comprehensive performance of the threaded reinforcement (such as better wear resistance, impact resistance, winding performance, etc.), on the other hand, such fibers have lower costs, which can reduce the material cost of the threaded reinforcement.

[0046] In some embodiments, as a specific implementation of the additional rib fiber bundle 4, the additional rib fiber bundle 4 is a carbon fiber bundle, a glass fiber bundle or a basalt fiber bundle.

[0047] In some embodiments, Figure 2 and 4 As shown, the depth h0 of the indentation groove is 0.1-0.5 mm, preferably, the depth h0 of the indentation groove 3 is 0.3 mm, the thickness t1 of the surface structural fiber bundle is 0.5-1 cmm, the height hr of the additional rib fiber bundle protruding from the surface of the surface structural fiber bundle is 0.08-0.15 times the outer diameter d1 of the surface structural fiber bundle, the outer diameter of the core axial fiber bundle 1 is d0, and the thickness of the surface structural fiber bundle 2 is t1, then the outer diameter d1 of the surface structural fiber bundle 2 is d1=d0+2t1.

[0048] In some embodiments, the pitch of the spiral indentation groove 3 is 10 to 30 mm; specifically, the pitch of the spiral indentation groove 3 is 10 mm, 15 mm, 20 mm, 25 mm, or 30 mm; preferably, the pitch of the spiral indentation groove 3 is 20 mm.

[0049] In some embodiments, the cross-section of the additional rib fiber bundle 4 is triangular, rectangular or trapezoidal; the cross-sectional shape of the additional rib fiber bundle 4 is not limited to the three cases listed above. In practical applications, it can be further personalized to meet the anchoring requirements of different concrete structures.

[0050] In some embodiments, at least two uniformly staggered spiral indentation grooves 3 are provided on the surface of the surface structural fiber bundle 2, thereby at least two uniformly staggered spiral additional rib fiber bundles 4 can be provided on the surface of the surface structural fiber bundle 2, thereby forming Figure 8 The double-threaded hybrid fiber threaded rebar and the multi-threaded hybrid fiber threaded rebar shown in the figure enable the rebar to have multiple spiral additional rib fiber bundles 4 in the same cross section, further improving the performance of the rebar.

[0051] In some embodiments, Figure 5 As shown, a method for manufacturing an embedded hybrid fiber threaded rib is disclosed, comprising the following steps:

[0052] S1, the core axial fiber bundle 1 and the surface structural fiber bundle 2 are impregnated with resin and then preformed by a circular preforming die 6 to obtain a preformed circular rod;

[0053] S2, a demoulding tape 7 is spirally wound on the surface of the preformed round rod, and then the preformed round rod is passed through a round forming mold 8, and solidified to obtain a round rod;

[0054] S3, after the round bar is demolded, the demoulding tape 7 is gradually removed to form a spiral indentation groove 3 on the surface of the round bar;

[0055] S4, after the additional rib fiber bundle 4 is impregnated with resin, it is wrapped and embedded in the spiral indentation groove 3, and the additional rib fiber bundle 4 is protruded from the surface of the surface structural fiber bundle 2 by a height of hr, and then cured in an oven 9.

[0056] In the above embodiment, the reinforcement body composed of the core axial fiber bundle 1 and the surface structural fiber bundle 2 is cured in the mold, which can effectively ensure the molding quality of the axial force fiber; the additional rib fiber bundle is bonded and cured by a post-curing process, allowing flexible design of the cross-sectional shape of the additional rib.

[0057] In some embodiments, in S2, at least two demoulding tapes are evenly and staggeredly wrapped around the surface of the preformed round rod; in S3, after the round rod is demolded, the demoulding tapes are gradually removed to form at least two evenly and staggered spiral indentation grooves on the surface of the round rod; at least two evenly and staggered spiral indentation grooves 3 are provided on the surface of the surface structural fiber bundle 2, thereby at least two evenly and staggered spiral additional rib fiber bundles 4 can be arranged on the surface of the surface structural fiber bundle 2, thereby forming double-threaded mixed fiber threaded ribs and multi-threaded mixed fiber threaded ribs.

[0058] As a specific implementation of the above embodiment, the thermoplastic fiber composite material is softened by heating the mold 10 and formed into a triangular, rectangular or trapezoidal cross-section; the additional rib scheme of the thermoplastic fiber composite material can easily realize the shaping of additional ribs of different shapes to meet different performance requirements, while saving the oven heating and curing process and reducing processing costs.

[0059] As a specific implementation of the above embodiment, in S2, the angle θ between the demoulding tape and the preformed round bar support is 45° to 70°; specifically, Wherein d1 is the outer diameter of the surface structural fiber bundle 2, dr is the pitch of the thread on the threaded rib; when a single thread is used, θ can be 65°; when a double thread is used, θ can be 50°.

[0060] In some embodiments, Figure 7 As shown, S1 can be replaced by:

[0061] S11, after the core axial fiber bundle 1 is impregnated with resin in the impregnation tank 5, it is cured and preformed by a circular first preforming mold 61 with a hole diameter d0 and a first forming mold 81 to obtain a core fiber bundle circular rod;

[0062] S12, after the surface structure fiber bundle 2 is impregnated with resin in the impregnation tank 5, it is distributed on the periphery of the core fiber bundle circular rod in S11, and is cured and preformed on the outside of the core axial fiber bundle 1 preformed in S11 through a second preforming mold 62 with a hole diameter of d1 to obtain a preformed circular rod;

[0063] In S11, the core axial fiber bundle is initially solidified so that the core axial fiber bundle does not produce radial deformation in the subsequent pultrusion process, thereby ensuring the orientation of the fibers in this part and giving full play to the performance of the carbon fibers in the core part.

[0064] In some embodiments, Figure 6 As shown, S4 is replaced by: the additional rib fiber bundle is made of thermoplastic fiber composite material, the thermoplastic fiber composite material is heated and softened by the heating mold 10, and is formed into the shape of the additional rib fiber bundle, and then is wrapped, bonded and embedded in the spiral indentation groove 3, and then naturally cooled and solidified.

[0065] As a specific implementation of the above embodiment, the core axial fiber bundle 1 is a carbon fiber bundle; the surface structural fiber bundle 2 is a glass fiber bundle, a basalt fiber bundle or an aramid fiber bundle; the additional rib fiber bundle 4 is a carbon fiber bundle, a glass fiber bundle or a basalt fiber bundle.

[0066] As a specific implementation of the above embodiment, the thickness of the demoulding tape in S2 is 0.1-0.5 mm, and the width of the demoulding tape is 5 mm; preferably, the thickness of the demoulding tape is 0.3 mm, and the width of the demoulding tape is 5 mm.

[0067] So far, various embodiments of the present invention have been described in detail. In order to avoid obscuring the concept of the present invention, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solution disclosed here.

[0068] The above-mentioned embodiments only express some implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. An embedded hybrid fiber threaded bar, characterized in that: It comprises a core axial fiber bundle, the outer side of which is provided with a cured surface structural fiber bundle, the outer side of which is provided with at least one spiral indentation groove, and the inner side of which is fixedly provided with a spiral additional rib fiber bundle along the indentation groove.

2. The embedded hybrid fiber threaded bar according to claim 1, characterized in that: The core axial fiber bundle is a carbon fiber bundle; the surface structural fiber bundle is a glass fiber bundle, a basalt fiber bundle or an aramid fiber bundle; and the additional rib fiber bundle is a carbon fiber bundle, a glass fiber bundle or a basalt fiber bundle.

3. The embedded hybrid fiber threaded bar according to claim 1, characterized in that: The depth h0 of the indentation groove is 0.1-0.5 mm, the thickness t1 of the surface structural fiber bundle is 0.5-1 cmm, and the height hr of the additional rib fiber bundle protruding from the surface of the surface structural fiber bundle is 0.08-0.15 times the outer diameter d1 of the surface structural fiber bundle.

4. The embedded hybrid fiber threaded bar according to claim 1, characterized in that: The cross section of the additional rib fiber bundle is triangular, rectangular or trapezoidal.

5. A method for manufacturing an embedded hybrid fiber threaded rib, characterized in that: The following steps are involved: S1, after the core axial fiber bundle and the surface structural fiber bundle are impregnated with resin, they are preformed through a circular preforming mold to obtain a preformed circular rod; S2, spirally wrapping a demoulding tape on the surface of the preformed round rod, and then passing through a round forming mold to obtain a round rod after curing; S3, after the round bar is demolded, the demoulding tape is gradually removed to form a spiral indentation groove on the surface of the round bar; S4, after the additional rib fiber bundle is impregnated with resin, it is wound and embedded in the spiral indentation groove, and the additional rib fiber bundle is protruded from the surface of the surface structural fiber bundle by a height of hr, and then cured in an oven.

6. The method for manufacturing the embedded hybrid fiber threaded rib according to claim 5, characterized in that: In S2, at least two demoulding tapes are evenly and staggeredly wound on the surface of the preformed round rod; In S3, after the round bar is demolded, the demoulding tape is gradually removed to form at least two uniformly staggered spiral indentation grooves on the surface of the round bar.

7. The method for manufacturing the embedded hybrid fiber threaded rib according to claim 5, characterized in that: In the above S2, the included angle θ between the demoulding tape and the preformed round rod support is 45° to 70°.

8. The method for manufacturing the embedded hybrid fiber threaded rib according to claim 5, characterized in that: The S1 can be replaced by: S11, after the core axial fiber bundle is impregnated with resin, it is cured and preformed through a circular first preforming mold with a hole diameter d0 and a first forming mold to obtain a core fiber bundle circular rod; S12, after the surface structural fiber bundle is impregnated with resin, it is distributed on the periphery of the core fiber bundle circular rod in S11, and is preformed on the outside of the core axial fiber bundle preformed in S11 through a second preforming mold with a hole diameter of d1 to obtain a preformed circular rod.

9. The method for manufacturing the embedded hybrid fiber threaded rib according to claim 5, characterized in that: The S4 is replaced by: the additional rib fiber bundle is made of thermoplastic fiber composite material, the thermoplastic fiber composite material is softened by heating the mold, and is formed into the shape of the additional rib fiber bundle, and then is wrapped, bonded and embedded in the spiral indentation groove, and then naturally cooled and solidified.

10. The method for manufacturing the embedded hybrid fiber threaded rib according to claim 5, characterized in that: The core axial fiber bundle is a carbon fiber bundle; the surface structural fiber bundle is a glass fiber bundle, a basalt fiber bundle or an aramid fiber bundle; and the additional rib fiber bundle is a carbon fiber bundle, a glass fiber bundle or a basalt fiber bundle.

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