High-strength woven fabric for reinforcing a bridge

Abstract

The application belongs to the technical field of carbon fiber composite materials, and particularly relates to a high-strength woven cloth for bridge reinforcement. The high-strength woven cloth is prepared by the following steps: S1, carbon fibers are used as warp yarns, and weft yarns are woven as weft yarns, and the carbon fibers and the weft yarns are woven into a two-dimensional fabric through two-dimensional weaving; S2, the two-dimensional fabric is formed by resin infusion, and is cured to obtain the high-strength woven cloth for bridge reinforcement. The high-strength woven cloth effectively improves the mechanical properties of the woven cloth through the synergistic effect between materials, so that the bridge reinforcement is realized.

Description

Technical Field

[0001] This invention belongs to the field of carbon fiber composite material technology, specifically relating to a high-strength woven fabric for bridge reinforcement. Background Technology

[0002] Globally, a large number of bridges have entered their aging stage, with structural performance deteriorating and safety hazards increasing, urgently requiring reinforcement and maintenance. High-grammage, high-strength woven fabrics can effectively improve the load-bearing capacity and durability of bridges, extending their service life and making them an ideal choice for bridge reinforcement. With increased global infrastructure investment and the continued growth in demand for bridge reinforcement, the high-grammage, high-strength woven fabric market will maintain rapid growth.

[0003] Carbon fiber woven fabric is a key reinforcing material for high-performance composite materials. It transforms the excellent mechanical properties and lightweight characteristics of carbon fiber into an easy-to-manage planar form through different weaving structures, enabling it to be impregnated with resin and cured into composite material parts with various complex shapes and excellent performance. It plays an irreplaceable role in cutting-edge technology and industrial fields that pursue ultimate lightweighting, high strength, high stiffness and durability.

[0004] High-strength woven fabric with carbon fiber as the main raw material has the following characteristics: (1) corrosion resistant, not corroded by chemicals such as acids, alkalis and salts, and suitable for harsh environments; (2) fatigue resistant, stable performance under long-term dynamic load, and long service life; (3) thermal stability, resistant to high temperature and low coefficient of thermal expansion, and good dimensional stability.

[0005] In existing technologies, the application of carbon fiber woven fabrics in bridge reinforcement suffers from insufficient mechanical properties. Therefore, it is necessary to explore how to use custom-woven weft yarns as weft threads, combined with radial carbon fibers as warp yarns to obtain a two-dimensional fabric, and then obtain a high-strength woven fabric through resin impregnation. By leveraging the interaction between the components, the tensile strength and elastic modulus of the woven fabric can be effectively improved, providing an efficient and reliable solution for bridge reinforcement. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a high-strength woven fabric for bridge reinforcement. This invention uses high-modulus and high-rigidity carbon fiber as the warp material and polyester fiber modified with catechol and N-aminoethyl-γ-aminopropyltrimethoxysilane as the weft material. The carbon fiber and polyester fiber are woven into a two-dimensional fabric through two-dimensional weaving, and then injection molded using carboxyl-modified epoxy resin. After curing, a high-strength woven fabric is obtained. Through the synergistic effect between the materials, the mechanical properties of the woven fabric are effectively improved, thereby achieving bridge reinforcement.

[0007] In a first aspect, the present invention provides a high-strength woven fabric for bridge reinforcement, the high-strength woven fabric being manufactured by the following steps: S1. Carbon fiber is used as warp yarn and braided weft yarn is used as weft yarn. Carbon fiber and braided weft yarn are woven into a two-dimensional fabric through two-dimensional weaving. S2. The two-dimensional fabric is molded by resin injection and cured to obtain a high-strength woven fabric for bridge reinforcement.

[0008] This invention combines woven weft yarns with radial carbon fibers to give the woven fabric extremely high tensile strength, effectively improving the load-bearing capacity of bridge structures; the high-density weft yarns can firmly bind the radial carbon fibers, avoiding stress concentration and improving impregnation and overall performance; at the same time, the resin injection molding process ensures that the resin quickly and evenly impregnates the woven fabric, forming a strong composite material and enhancing the reinforcement effect.

[0009] As a preferred embodiment of the present invention, the carbon fiber has a tensile strength ≥6000MPa, an elastic modulus ≥265GPa, an elongation ≥2.2%, and a linear density ≥1800g / km.

[0010] As a preferred technical solution of the present invention, the carbon fiber is preferably Zhongfu Shenying SYT50S carbon fiber.

[0011] The carbon fiber used in this invention is Zhongfu Shenying SYT50S, which has a tensile strength of 6000MPa, an elastic modulus of 265GPa, and an elongation of 2.2%. Through the high modulus and high rigidity of the carbon fiber itself, it is ensured that it is not easy to buckle at the interlacing point, and the load can be transferred to adjacent fibers more evenly, reducing local overload, avoiding mutual compression of warp and weft fibers at the interlacing point in the woven fabric, and reducing stress concentration.

[0012] As a preferred embodiment of the present invention, the weft yarn is surface-modified polyester fiber.

[0013] As a preferred technical solution of the present invention, the preparation method of the surface-modified polyester fiber is as follows: the polyester fiber is immersed in the modification solution for surface modification treatment, washed with water, and dried to obtain the surface-modified polyester fiber.

[0014] This invention modifies the surface of polyester fibers by grafting silane coupling agents using a polyphenol amine method. Catechol is first oxidized under alkaline conditions to generate benzoquinone, which reacts with N-aminoethyl-γ-aminopropyltrimethoxysilane to form a network structure. At the same time, the silanol generated by the hydrolysis of the silane coupling agent undergoes a condensation reaction with the polyester fibers, causing the product to be deposited on the surface of the polyester fibers, thus forming surface-modified polyester fibers.

[0015] As a preferred technical solution of the present invention, the preparation steps of the modified liquid are as follows: by weight, 0.2-0.4 parts of catechol are added to 400-500 parts of deionized water and stirred to dissolve, then 0.2-0.4 parts of N-aminoethyl-γ-aminopropyltrimethoxysilane are added and stirred for 10-20 minutes, and then the pH is adjusted to 10.4-10.8 with sodium hydroxide solution to obtain the modified liquid.

[0016] As a preferred embodiment of the present invention, the catechol may be present in weight parts of 0.2 parts, 0.25 parts, 0.3 parts, 0.35 parts, or 0.4 parts, etc.

[0017] As a preferred embodiment of the present invention, the weight parts of the N-aminoethyl-γ-aminopropyltrimethoxysilane may be 0.2 parts, 0.25 parts, 0.3 parts, 0.35 parts, or 0.4 parts, etc.

[0018] As a preferred embodiment of the present invention, the surface modification treatment is performed at a temperature of 50-60°C for a time of 40-60 minutes.

[0019] As a preferred embodiment of the present invention, the drying temperature is 70~80℃ and the drying time is 6~8h.

[0020] The surface-modified polyester fiber of the present invention forms a phenol-amine network structure on the fiber surface through the synergistic effect of catechol-silane coupling agent, which fills the micropores, scratches and other defects on the fiber surface, reduces stress concentration points, and makes the fiber more uniformly stressed. At the same time, the dense cross-linked network reduces the expansion of surface defects of the fiber under stress, effectively improving the mechanical properties of the woven fabric.

[0021] As a preferred embodiment of the present invention, the density of warp yarns in the two-dimensional fabric described in step S1 is 50-60 yarns / inch, and the density of weft yarns is 45-55 yarns / inch.

[0022] As a preferred embodiment of the present invention, the resin injection molding pressure in step S2 is 0.1~0.5MPa.

[0023] As a preferred technical solution of the present invention, the resin used for resin injection molding in step S2 is epoxy resin.

[0024] As a preferred embodiment of the present invention, the epoxy resin is a carboxyl-modified epoxy resin, wherein the epoxy equivalent of the carboxyl-modified epoxy resin is 220~250 g / eq and the viscosity is 20000~60000 cps.

[0025] As a preferred embodiment of the present invention, the curing temperature is 80~100℃ and the curing time is 4~6h.

[0026] The carboxyl-modified epoxy resin of the present invention introduces carboxyl-containing flexible segments by chemically grafting terminal carboxyl-terminated liquid nitrile rubber onto the epoxy resin. The flexible segments can buffer local stress through their own deformation, avoid matrix failure caused by brittle fracture, and at the same time maintain the adhesion and support to the fibers, reduce stress concentration and cracking, and improve the strength of the woven fabric.

[0027] As a preferred embodiment of the present invention, the high-strength woven fabric for bridge reinforcement has a tensile strength ≥4400MPa, an elastic modulus ≥230GPa, and an elongation ≥1.6%.

[0028] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention combines the weft yarn and the radial carbon fiber to give the woven fabric extremely high tensile strength, effectively improving the load-bearing capacity of the bridge structure; the high-density weft yarn can firmly bind the radial carbon fiber, avoid stress concentration, and improve the permeability and overall performance; at the same time, the resin injection molding process ensures that the resin quickly and evenly permeates the woven fabric to form a strong composite material and enhance the reinforcement effect. (2) The surface-modified polyester fiber of the present invention forms a phenol-amine network structure on the fiber surface through the synergistic effect of catechol-silane coupling agent, which fills the micropores, scratches and other defects on the fiber surface, reduces stress concentration points, makes the fiber more uniformly stressed, and at the same time, the dense cross-linked network reduces the expansion of surface defects of the fiber under stress, effectively improving the mechanical properties of the woven fabric. (3) The carboxyl-modified epoxy resin of the present invention introduces a carboxyl-containing flexible segment by chemically grafting a carboxyl-terminated liquid nitrile rubber onto the epoxy resin. The flexible segment can buffer local stress through its own deformation, avoid matrix failure caused by brittle fracture, and at the same time maintain the bonding and support of the fiber, reduce stress concentration and cracking, and improve the strength of the woven fabric. (4) The surface-modified polyester fiber of the present invention introduces active groups hydroxyl and amino on the surface of the polyester fiber through catechol and N-aminoethyl-γ-aminopropyltrimethoxysilane. It can interact with the strong polar groups carboxyl in the carboxyl-modified epoxy resin during the resin transfer molding process. The fiber and resin are anchored by covalent bonds. The strong interfacial adhesion can ensure the efficient transfer of stress between the fiber and the resin. When the woven fabric is stretched by external force, the stress borne by the resin matrix can be quickly transferred to the high-strength fiber through the interface. The fiber fully bears the load, thereby improving the overall strength of the woven fabric. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0030] Figure 1This is the XPS pattern of the surface-modified polyester fiber in Example 1.

[0031] Figure 2 This is a graph showing the tensile strength data of the embodiments and comparative examples of the present invention.

[0032] Figure 3 This is a graph showing the elastic modulus data of the embodiments and comparative examples of the present invention.

[0033] Figure 4 This is a graph showing the elongation data of the embodiments and comparative examples of the present invention. Detailed Implementation

[0034] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0035] The sources of some components in the examples and comparative examples are as follows: Carbon fiber A, model SYT50S, has a tensile strength of 6000MPa, an elastic modulus of 265GPa, and an elongation of 2.2%, and was purchased from Zhongfu Shenying Carbon Fiber Co., Ltd. Carbon fiber B, model SYT45, has a tensile strength of 4000MPa, an elastic modulus of 220GPa, and an elongation of 1.5%, and was purchased from Zhongfu Shenying Carbon Fiber Co., Ltd. Polyester fiber, item number HF30, purchased from Weifang Huafeng Textile Co., Ltd. Carboxyl-modified epoxy resin, model HQ-3600S, with an epoxy equivalent of 220~250g / eq and a viscosity of 20000~60000cps, was purchased from Hunan Servi New Material Technology Co., Ltd. Hydrogenated epoxy resin, model SHZ-3720, with an epoxy equivalent of 230~260g / eq and a viscosity of 40000~80000cps, was purchased from Hunan Servi New Material Technology Co., Ltd. Catechol, CAS No. 120-80-9, purchased from Shanghai Maclean Biochemical Technology Co., Ltd. N-aminoethyl-γ-aminopropyltrimethoxysilane, CAS No. 1760-24-3, was purchased from Shanghai Maclean Biochemical Technology Co., Ltd.

[0036] Example 1: This example provides a high-strength woven fabric for bridge reinforcement, which is manufactured by the following steps: S1. Carbon fiber A (model SYT50S, purchased from Zhongfu Shenying) is used as warp yarn, and braided weft yarn is used as weft yarn. The carbon fiber and braided weft yarn are woven into a two-dimensional fabric through two-dimensional weaving. The density of the warp yarn is 60 threads / inch, and the density of the weft yarn is 55 threads / inch. S2. The two-dimensional fabric is injection molded with carboxyl-containing epoxy resin (model HQ-3600S, purchased from Hunan Servi) (pressure of 0.5MPa) and cured at 100°C for 4 hours to obtain a high-strength woven fabric for bridge reinforcement.

[0037] The preparation method of the surface-modified polyester fiber is as follows: by weight, 0.4 parts of catechol are added to 500 parts of deionized water and stirred to dissolve. Then, 0.4 parts of N-aminoethyl-γ-aminopropyltrimethoxysilane are added and stirred for 20 min. The pH is then adjusted to 10.8 with sodium hydroxide solution to obtain a modified solution. The polyester fiber is immersed in the modified solution for surface modification treatment (temperature 60℃, time 40 min), washed three times with deionized water, and dried at 80℃ for 6 h to obtain the surface-modified polyester fiber.

[0038] Example 2: This example provides a high-strength woven fabric for bridge reinforcement, which is made by the following steps: S1. Carbon fiber A (model SYT50S, purchased from Zhongfu Shenying) is used as warp yarn, and braided weft yarn is used as weft yarn. The carbon fiber and braided weft yarn are woven into a two-dimensional fabric through two-dimensional weaving. The density of the warp yarn is 50 threads / inch, and the density of the weft yarn is 45 threads / inch. S2. The two-dimensional fabric is injection molded with carboxyl-containing epoxy resin (model HQ-3600S, purchased from Hunan Servi) (pressure 0.1MPa) and cured at 80℃ for 6h to obtain a high-strength woven fabric for bridge reinforcement.

[0039] The preparation method of the surface-modified polyester fiber is as follows: by weight, 0.2 parts of catechol are added to 400 parts of deionized water and stirred to dissolve. Then, 0.2 parts of N-aminoethyl-γ-aminopropyltrimethoxysilane are added and stirred for 10 min. The pH is then adjusted to 10.4 with sodium hydroxide solution to obtain a modified solution. The polyester fiber is immersed in the modified solution for surface modification treatment (temperature 50℃, time 60 min), washed three times with deionized water, and dried at 70℃ for 8 h to obtain the surface-modified polyester fiber.

[0040] Example 3: This example provides a high-strength woven fabric for bridge reinforcement, which is made by the following steps: S1. Carbon fiber A (model SYT50S, purchased from Zhongfu Shenying) is used as warp yarn, and braided weft yarn is used as weft yarn. The carbon fiber and braided weft yarn are woven into a two-dimensional fabric through two-dimensional weaving. The density of the warp yarn is 55 threads / inch, and the density of the weft yarn is 50 threads / inch. S2. The two-dimensional fabric is injection molded with carboxyl-containing epoxy resin (model HQ-3600S, purchased from Hunan Servi) (pressure 0.3MPa) and cured at 90℃ for 5h to obtain a high-strength woven fabric for bridge reinforcement.

[0041] The preparation method of the surface-modified polyester fiber is as follows: by weight, 0.3 parts of catechol are added to 450 parts of deionized water and stirred to dissolve. Then, 0.3 parts of N-aminoethyl-γ-aminopropyltrimethoxysilane are added and stirred for 15 min. The pH is then adjusted to 10.6 with sodium hydroxide solution to obtain a modified solution. The polyester fiber is immersed in the modified solution for surface modification treatment (temperature 55℃, time 50 min), washed three times with deionized water, and dried at 75℃ for 7 h to obtain the surface-modified polyester fiber.

[0042] Comparative Example 1 The difference between this comparative example and Example 1 is that carbon fiber B (model SYT45) is used instead of carbon fiber A (model SYT50S).

[0043] Comparative Example 2 The difference between this comparative example and Example 1 is that commercially available polyester fiber (item number HF30) was used instead of surface-modified polyester fiber.

[0044] Comparative Example 3 The difference between this comparative example and Example 1 is that hydrogenated epoxy resin is used instead of carboxyl-modified epoxy resin.

[0045] The woven fabrics provided in the above examples and comparative examples were tested in accordance with GB / T 3354-2014 Test Method for Tensile Properties of Directed Fiber Reinforced Polymer Matrix Composites.

[0046] The performance test data above are shown in Table 1.

[0047] Table 1 Performance Test Results

[0048] As can be seen from the above, the present invention selects high modulus and high rigidity carbon fiber as warp material and polyester fiber modified with catechol and N-aminoethyl-γ-aminopropyltrimethoxysilane as weft material. The carbon fiber and polyester fiber are woven into a two-dimensional fabric through two-dimensional weaving, and then injection molding is performed using carboxyl-modified epoxy resin. After curing, a high-strength woven fabric is obtained (Examples 1 to 3). Through the synergistic effect between the materials, the mechanical properties of the woven fabric are effectively improved.

[0049] Compared to Example 1, carbon fiber B (model SYT45) was used instead of carbon fiber A (model SYT50S). Due to the lower tensile strength, elastic modulus, and elongation of carbon fiber B, the carbon fiber support effect was poor, resulting in a deterioration in the mechanical properties of the woven fabric (Comparative Example 1). Compared to Example 1, commercially available polyester fiber (item number HF30) was used instead of surface-modified polyester fiber. Since commercially available polyester fiber is not surface-modified, the mechanical properties of the woven fabric deteriorated (Comparative Example 2). Compared to Example 1, hydrogenated epoxy resin was used instead of carboxyl-modified epoxy resin. Due to the lack of carboxyl group effect, the mechanical properties of the woven fabric deteriorated (Comparative Example 3).

Claims

1. A high-strength woven fabric for bridge reinforcement, characterized in that, The high-strength woven fabric is made by the following steps: S1. Carbon fiber is used as warp yarn and braided weft yarn is used as weft yarn. Carbon fiber and braided weft yarn are woven into a two-dimensional fabric through two-dimensional weaving. S2. The two-dimensional fabric is molded by resin injection and cured to obtain a high-strength woven fabric for bridge reinforcement.

2. The high-strength woven fabric for bridge reinforcement according to claim 1, characterized in that, The carbon fiber has a tensile strength ≥6000MPa, an elastic modulus ≥265GPa, an elongation ≥2.2%, and a linear density ≥1800g / km.

3. The high-strength woven fabric for bridge reinforcement according to claim 1, characterized in that, The weft yarn is surface-modified polyester fiber.

4. The high-strength woven fabric for bridge reinforcement according to claim 3, characterized in that, The preparation method of the surface-modified polyester fiber is as follows: the polyester fiber is immersed in the modification solution for surface modification treatment, washed with water, and dried to obtain the surface-modified polyester fiber.

5. The high-strength woven fabric for bridge reinforcement according to claim 4, characterized in that, The preparation steps of the modified solution are as follows: by weight, 0.2-0.4 parts of catechol are added to 400-500 parts of deionized water and stirred to dissolve. Then, 0.2-0.4 parts of N-aminoethyl-γ-aminopropyltrimethoxysilane are added and stirred for 10-20 minutes. The pH is then adjusted to 10.4-10.8 with sodium hydroxide solution to obtain the modified solution.

6. The high-strength woven fabric for bridge reinforcement according to claim 1, characterized in that, In step S1, the density of warp yarns in the two-dimensional fabric is 50-60 yarns / inch, and the density of weft yarns is 45-55 yarns / inch.

7. The high-strength woven fabric for bridge reinforcement according to claim 1, characterized in that, The resin injection molding pressure in step S2 is 0.1~0.5MPa.

8. The high-strength woven fabric for bridge reinforcement according to claim 1, characterized in that, The resin used in step S2 for resin injection molding is epoxy resin.

9. A high-strength woven fabric for bridge reinforcement according to claim 8, characterized in that, The epoxy resin is a carboxyl-modified epoxy resin, and the epoxy equivalent of the carboxyl-modified epoxy resin is 220~250 g / eq, and the viscosity is 20000~60000 cps.

10. A high-strength woven fabric for bridge reinforcement according to claim 1, characterized in that, The high-strength woven fabric used for bridge reinforcement has a tensile strength ≥4400MPa, an elastic modulus ≥230GPa, and an elongation ≥1.6%.

Images