Steel fiber reinforced hybrid FRP stirrup confined concrete member
By using steel fiber reinforced hybrid FRP stirrups in concrete structures, the problem of corrosion of reinforced concrete in a corrosive environment is solved, the durability and corrosion resistance of concrete are improved, and the needs of high strength and high ductility are met.
Patent Information
- Application Number
- CN202420867576.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-24
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2034-04-24
AI Technical Summary
Reinforced concrete structures are prone to corrosion in a corrosive environment, have poor durability, and have low compressive strength and poor ductility of a single FRP stirrup, which cannot effectively replace steel bars.
The hybrid FRP stirrups reinforced by steel fiber are used to embed concrete in the FRP cage, and the ductility and durability of the concrete are improved by using mixed FRP stirrups braided by multiple fibers, thereby enhancing its corrosion resistance.
It significantly improves the durability and corrosion resistance of concrete components, reduces the cost of post-reinforcement and maintenance, and improves the mechanical properties and ductility of concrete.
Smart Images
Figure CN222161748U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of concrete, in particular to a steel fiber reinforced hybrid FRP stirrup restrained concrete component. Background Art
[0002] There are many problems with reinforced concrete during use, such as heavy weight, poor durability in corrosive and other adverse environments, and interference with electromagnetic waves. As the use time goes by, the reinforced concrete structure in the corrosive environment will continue to suffer from corrosion and deterioration problems, among which steel corrosion is the most common. In the reinforced concrete structure under normal use environment, the steel bars are protected by alkaline concrete and are not easy to rust, which makes the reinforced concrete structure have a certain durability. However, for reinforced concrete structures exposed to corrosive environments (such as bridges treated with deicing salt, seaside buildings, and certain chemical plants, etc.), under suitable temperature and humidity conditions, the concrete gradually becomes neutral due to the intrusion of carbonization and chlorides, so that the passivation film on the surface of the steel bars is destroyed, and then corrosion begins, which eventually leads to damage and even destruction of the reinforced concrete structure. This not only affects the normal use and life of the engineering structure, but also causes engineering safety accidents and hidden dangers. For this reason, a lot of manpower and material resources are needed for its reinforcement and maintenance.
[0003] In order to solve the above problems, the existing fiber reinforced polymer FRP (Fiber Reinforced Polymer), due to its advantages such as high tensile strength, low density, good corrosion resistance, excellent fatigue resistance and good electromagnetic insulation, is considered to be a new type of material that can replace steel bars to solve the problems of steel bar corrosion in corrosive environments and the inability to use steel bars in special environments.
[0004] However, FRP stirrups made of FRP materials also have some unfavorable characteristics. The compressive strength of FRP stirrups is significantly lower than its tensile strength, the compressive elastic modulus is lower than its tensile elastic modulus, and the ductility is poor. The elastic modulus is relatively low compared to steel. The elastic modulus of FRP stirrups is generally about 25% to 75% of that of steel bars. The shear strength is low. FRP bars are anisotropic materials, and the transverse shear strength of FRP bars is low compared to steel bars. Generally, it does not exceed 10% of the tensile strength. FRP stirrups are inconvenient to process on site, mainly because FRP stirrups use thermosetting resin. After shaping, their shape is fixed, and the shape of the bars cannot be changed arbitrarily during on-site construction.
[0005] In reinforced concrete structures, the ductility of reinforced concrete structures does not depend solely on the concrete, but also on the configuration of the steel bars. Reinforced concrete structures using single FRP stirrups have the problem of poor ductility. Utility Model Content
[0006] In view of the above problems in the prior art, the utility model provides a steel fiber reinforced hybrid FRP stirrup confined concrete member, which solves the problem of poor durability of the existing reinforced concrete structure.
[0007] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:
[0008] Provided is a steel fiber reinforced hybrid FRP stirrup restrained concrete component, comprising an FRP cage, in which concrete is poured; the FRP cage comprises a plurality of longitudinal bars and a plurality of hybrid FRP stirrups, wherein the plurality of hybrid FRP stirrups are all arranged on the plurality of longitudinal bars; each hybrid FRP stirrup comprises a polymer matrix, on which a plurality of fiber lines are wound in tension and compression, and each fiber line is formed by winding and weaving steel fiber and one or more of carbon fiber, glass fiber, basalt fiber, polyethylene fiber, aramid fiber, polyvinyl alcohol fiber, polyester fiber or nylon fiber.
[0009] The working principle of this scheme is as follows: since the ductility of reinforced concrete structures does not only depend on concrete, but also on the configuration of steel bars, this scheme uses the steel fibers of hybrid FRP stirrups to enhance the constraints of hybrid FRP stirrups on concrete, improve the ductility of concrete components, and overcome the brittleness of concrete, improving the mechanical properties of concrete. In addition, the steel fibers mixed in the hybrid FRP stirrups improve the durability of concrete. Compared with concrete components using ordinary steel stirrups and FRP stirrups, the corrosion resistance and durability of this scheme have been significantly improved, reducing the cost of later reinforcement and maintenance.
[0010] Furthermore, each fiber line includes carbon fiber, glass fiber, basalt fiber, polyethylene fiber and steel fiber, and the number ratio of carbon fiber, glass fiber, basalt fiber, polyethylene fiber and steel fiber is 2:1:1:1:1.
[0011] Furthermore, each fiber line includes carbon fiber, polyvinyl alcohol fiber, polyester fiber, nylon fiber, and steel fiber in a root quantity ratio of 2:1:1:1:1.
[0012] Furthermore, each fiber line includes carbon fiber, aramid fiber, polyester fiber, nylon fiber, and steel fiber in a root quantity ratio of 2:1:1:1:1.
[0013] Furthermore, the length of each steel fiber is greater than or equal to 6 mm, which is beneficial to improving the shear strength of the hybrid FRP stirrups.
[0014] Furthermore, the outer edge of each hybrid FRP stirrup is circular or rectangular.
[0015] Furthermore, the center of each hybrid FRP stirrup is in a cross shape, a tic-tac-toe shape, a diamond shape or a circle.
[0016] Furthermore, the outer edge of each hybrid FRP stirrup is spiral-shaped, and both ends of the hybrid FRP stirrup are bent into a hook shape.
[0017] Furthermore, each longitudinal reinforcement is an FRP reinforcement or a steel reinforcement.
[0018] The utility model discloses a steel fiber reinforced hybrid FRP stirrup restrained concrete component, which has the following beneficial effects:
[0019] 1. The utility model improves the durability of concrete through hybrid FRP stirrups, and has higher ductility than existing reinforced concrete components using single FRP stirrups. Hybrid FRP stirrups are made of steel fibers and multiple FRP fibers mixed and woven together, so that the hybrid FRP stirrups have high strength, corrosion resistance, strong energy dissipation capacity and certain ductility.
[0020] 2. The various forms of the hybrid FRP stirrups of the utility model can meet the requirements of different component cross-sectional shapes, design strengths and construction difficulty. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 Schematic diagram of a concrete member confined by steel fiber reinforced hybrid FRP stirrups
[0022] Figure 2 It is a schematic diagram of the cross section of the U-shaped stirrup 11 reinforcement;
[0023] Figure 3 It is a schematic diagram of the cross section of circular stirrups;
[0024] Figure 4 Schematic diagram of hybrid FRP stirrups;
[0025] Figure 5 Schematic diagram of hybrid FRP stirrup structure;
[0026] Figure 6 Schematic diagram of the cross-shaped hybrid FRP stirrups;
[0027] Figure 7 The schematic diagram of the structure of the cross-shaped hybrid FRP stirrups;
[0028] Figure 8 The schematic diagram of the FRP stirrups with a tic-tac-toe shape inside;
[0029] Fig. 9 The schematic diagram of the structure of the hybrid FRP stirrups with a tic-tac-toe shape inside;
[0030] Fig.10 Schematic diagram of hybrid FRP stirrups with diamond-shaped interior;
[0031] Fig.11 The schematic diagram of the structure of the hybrid FRP stirrups with diamond-shaped interior;
[0032] Fig.12 It is a schematic diagram of the hybrid FRP stirrup with circular interior;
[0033] Fig.13 The schematic diagram of the structure of the hybrid FRP stirrup with circular interior;
[0034] Fig.14 Schematic diagram of spiral hybrid FRP stirrups;
[0035] Fig.15 It is a schematic diagram of the spiral hybrid FRP stirrup structure;
[0036] Fig.16 Schematic diagram of spiral hybrid FRP stirrups;
[0037] Fig.17 It is a schematic diagram of the spiral hybrid FRP stirrup structure;
[0038] Among them: 1. mixed FRP stirrups; 2. longitudinal reinforcement; 11. U-shaped stirrups; 12. circular stirrups; 13. first rectangular structure; 14. second rectangular structure. DETAILED DESCRIPTION
[0039] The specific implementation methods of the utility model are described below to facilitate technical personnel in this technical field to understand the utility model, but it should be clear that the utility model is not limited to the scope of the specific implementation methods. For ordinary technical personnel in this technical field, as long as various changes are within the spirit and scope of the utility model defined and determined by the attached claims, these changes are obvious, and all utility model creations using the concept of the utility model are protected.
[0040] Example 1
[0041] refer to Figure 1 The present embodiment provides a steel fiber reinforced hybrid FRP stirrup confined concrete member, including an FRP cage, in which concrete is poured.
[0042] The FRP reinforcement cage comprises a plurality of longitudinal reinforcements 2 and a plurality of hybrid FRP stirrups 1. The plurality of hybrid FRP stirrups 1 are all arranged on the plurality of longitudinal reinforcements 2. Each longitudinal reinforcement 2 is an FRP reinforcement or a steel bar.
[0043] Each hybrid FRP stirrup 1 comprises a polymer matrix on which a plurality of fiber lines are wound in tension and compression, and each fiber line is braided by winding and weaving steel fiber and one or more of carbon fiber, glass fiber, basalt fiber, polyethylene fiber, aramid fiber, polyvinyl alcohol fiber, polyester fiber or nylon fiber.
[0044] The working principle of this scheme is as follows: in reinforced concrete structures, the ductility of reinforced concrete structures does not only depend on concrete, but also on the configuration of steel bars. This scheme uses the steel fibers of the hybrid FRP stirrups 1 to enhance the constraints of the hybrid FRP stirrups 1 on concrete, improve the ductility of concrete components, and overcome the brittleness of concrete, thereby improving the mechanical properties of concrete. Moreover, the steel fibers mixed in the hybrid FRP stirrups 1 improve the durability of concrete. Compared with concrete components using ordinary steel stirrups and FRP stirrups, the corrosion resistance and durability of this scheme have been significantly improved, reducing the cost of later reinforcement and maintenance.
[0045] Specifically, this embodiment provides three types of fiber lines.
[0046] The fiber line may include carbon fiber, glass fiber, basalt fiber, polyethylene fiber and steel fiber, and the number ratio of the carbon fiber, glass fiber basalt fiber, polyethylene fiber and steel fiber is 2:1:1:1:1.
[0047] The fiber line may also include carbon fiber, polyvinyl alcohol fiber, polyester fiber, nylon fiber, and steel fiber in a root number ratio of 2:1:1:1:1.
[0048] The fiber line may also include carbon fiber, aramid fiber, polyester fiber, nylon fiber, and steel fiber in a root number ratio of 2:1:1:1:1.
[0049] Wherein, the length of each steel fiber is greater than or equal to 6 mm, which is beneficial to improving the shear strength of the hybrid FRP stirrup 1.
[0050] Specifically, refer to Figure 2 and Figure 3 The basic components of the hybrid FRP stirrups 1 are U-shaped stirrups 11 and circular stirrups 12. Preferably, Figure 4 and Figure 5 The outer edge of the hybrid FRP stirrup 1 in this embodiment is a first rectangular structure 13, and the first rectangular structure 13 is composed of two U-shaped stirrups 11. The overlapping parts of the two U-shaped stirrups 11 are fastened and connected by a thin rope or a nylon tie.
[0051] Example 2
[0052] refer to Figure 6 and Figure 7 This embodiment is further limited on the basis of the embodiment 1, and the specific improvement lies in how to set the shape of the hybrid FRP stirrups 1. For other parts not mentioned, refer to the embodiment 1 or the prior art.
[0053] The outer edge of the hybrid FRP stirrup 1 in this embodiment is rectangular, and the inner part is cross-shaped.
[0054] Specifically, the processing method of the hybrid FRP stirrup 1 is:
[0055] First, two U-shaped hoops 11 are connected opposite to each other to form a first rectangular structure 13, and then the two U-shaped hoops 11 are crossed to form a cross and fixed to the rectangular structure by a thin rope or nylon tie.
[0056] Example 3
[0057] refer to Figure 8 and Fig. 9 This embodiment is further limited on the basis of the embodiment 1, and the specific improvement lies in how to set the shape of the hybrid FRP stirrups 1. For other parts not mentioned, refer to the embodiment 1 or the prior art.
[0058] The outer edge of the hybrid FRP stirrup 1 in this embodiment is rectangular, and the inside is in a tic-tac-toe shape.
[0059] Specifically, the processing method of the hybrid FRP stirrup 1 is:
[0060] First, two U-shaped hoops 11 are connected opposite to each other to form a first rectangular structure 13, and then the four U-shaped hoops 11 are divided into two groups. Each group of U-shaped hoops 11 are connected opposite to each other to form a second rectangular structure 14. The width of the second rectangular structure 14 is smaller than the width of the first rectangular structure 13, and the two second rectangular structures 14 are arranged perpendicular to each other in the middle of the first rectangular structure 13.
[0061] Example 4
[0062] refer to Fig.10 and Fig.11 This embodiment is further limited on the basis of the embodiment 1, and the specific improvement lies in how to set the shape of the hybrid FRP stirrups 1. For other parts not mentioned, refer to the embodiment 1 or the prior art.
[0063] The outer edge of the hybrid FRP stirrup 1 in this embodiment is rectangular, and the inner part is rhombus-shaped.
[0064] Specifically, the processing method of the hybrid FRP stirrup 1 is:
[0065] First, two U-shaped hoops 11 are connected opposite to each other to form a first rectangular structure 13 , and then the two U-shaped hoops 11 are overlapped and connected opposite to each other to form a diamond structure, which is arranged in the middle of the first rectangular structure 13 .
[0066] Example 5
[0067] refer to Fig.12 and Fig.13 This embodiment is further limited on the basis of the embodiment 1, and the specific improvement lies in how to set the shape of the hybrid FRP stirrups 1. For other parts not mentioned, refer to the embodiment 1 or the prior art.
[0068] The outer edge of the hybrid FRP stirrup 1 in this embodiment is rectangular and the inner part is circular.
[0069] Specifically, the processing method of the hybrid FRP stirrup 1 is:
[0070] First, two U-shaped hoops 11 are connected oppositely to form a first rectangular structure 13, and then the circular hoop 12 is arranged in the middle of the first rectangular structure 13 by a thin rope or nylon tie.
[0071] Example 6
[0072] This embodiment is further limited on the basis of the embodiment 1, and the specific improvement lies in how to set the shape of the hybrid FRP stirrups 1. For other parts not mentioned, refer to the embodiment 1 or the prior art.
[0073] refer to Figure 14 to Figure 17 The hybrid FRP stirrup 1 in this embodiment is a spiral structure with a rectangular or circular outer edge, and both ends of the spiral structure are bent outward into a hook shape.
[0074] Specifically, refer to Fig.15 The spiral structure with a rectangular outer edge is formed by connecting multiple sets of U-shaped hoops 11 end to end in sequence. Fig.17 The spiral structure with a circular outer edge is formed by connecting multiple groups of circular hoops 12 end to end in sequence.
[0075] In summary, the hybrid FRP stirrup 1 of this solution can be formed into various forms through the U-shaped stirrup 11 and the circular stirrup 12, which can meet the requirements of different component cross-sectional shapes, design strength and construction difficulty. Although the specific implementation of the utility model is described in detail in conjunction with the drawings, it should not be understood as a limitation on the protection scope of this patent. Within the scope described in the claims, various modifications and deformations that can be made by technical personnel in this field without creative work still fall within the protection scope of this patent.
Claims
1. A steel fiber reinforced hybrid FRP stirrup confined concrete member, It is characterized in that It comprises an FRP reinforcement cage, in which concrete is poured; The FRP reinforcement cage comprises a plurality of longitudinal reinforcements (2) and a plurality of hybrid FRP stirrups (1), wherein the plurality of hybrid FRP stirrups (1) are all arranged on the plurality of longitudinal reinforcements (2); Each hybrid FRP stirrup (1) comprises a polymer matrix, on which a plurality of fiber threads are wound in tension and compression, and each fiber thread is braided by winding and weaving steel fibers and one or more of carbon fibers, glass fibers, basalt fibers, polyethylene fibers, aramid fibers, polyvinyl alcohol fibers, polyester fibers or nylon fibers.
2. The steel fiber reinforced hybrid FRP stirrup confined concrete member according to claim 1, It is characterized in that Each of the fiber lines includes carbon fiber, glass fiber, basalt fiber, polyethylene fiber and steel fiber, and the number ratio of carbon fiber, glass fiber, basalt fiber, polyethylene fiber and steel fiber is 2:1:1:1:
1.
3. The steel fiber reinforced hybrid FRP stirrup confined concrete member according to claim 1, It is characterized in that Each of the fiber lines includes carbon fiber, polyvinyl alcohol fiber, polyester fiber, nylon fiber, and steel fiber in a root quantity ratio of 2:1:1:1:
1.
4. The steel fiber reinforced hybrid FRP stirrup confined concrete member according to claim 1, It is characterized in that Each of the fiber lines includes carbon fiber, aramid fiber, polyester fiber, nylon fiber, and steel fiber in a root quantity ratio of 2:1:1:1:
1.
5. The steel fiber reinforced hybrid FRP stirrup confined concrete member according to claim 1, It is characterized in that The length of each steel fiber is greater than or equal to 6 mm.
6. The steel fiber reinforced hybrid FRP stirrup confined concrete member according to claim 1, It is characterized in that The outer edge of each hybrid FRP stirrup (1) is circular or rectangular.
7. The steel fiber reinforced hybrid FRP stirrup confined concrete member according to claim 6, It is characterized in that The center of each hybrid FRP stirrup (1) is in a cross shape, a tic-tac-toe shape, a diamond shape or a circle.
8. The steel fiber reinforced hybrid FRP stirrup confined concrete member according to claim 1, It is characterized in that The outer edge of each of the hybrid FRP stirrups (1) is spiral-shaped, and both ends of the hybrid FRP stirrups (1) are bent into a hook shape.
9. The steel fiber reinforced hybrid FRP stirrup confined concrete member according to claim 1, It is characterized in that Each of the longitudinal bars (2) is an FRP bar or a steel bar.