A method for reinforcing corroded reinforced concrete columns with FRP reinforcement and mesh.

Abstract

This invention provides a method for reinforcing a corroded reinforced concrete column with FRP (fiberglass reinforced plastic) reinforcement-mesh composite structure. The structure includes: a concrete column having a portion to be reinforced and exposed corroded reinforcing steel bars after the concrete cover of the portion to be reinforced has been removed; an FRP reinforcement-mesh composite layer, formed by bonding FRP bars and FRP mesh, wrapped around the outer side of the core area of ​​the concrete column after the concrete cover has been removed, providing longitudinal reinforcement and lateral restraint to strengthen the internal concrete of the portion to be reinforced; several fasteners for securing the FRP reinforcement-mesh composite layer; and ultra-high performance concrete filling both the inner and outer sides of the FRP reinforcement-mesh composite layer, bonding the composite layer to the reinforced concrete column to repair the removed concrete cover and restore the column's cross-section to its original dimensions. This reinforcement structure enhances the strength and deformation capacity of the internal concrete, increases the axial compression, bending, and shear resistance of the corroded reinforced concrete column, and improves the column's durability.

Description

Technical Field

[0001] This invention relates to the field of building repair technology, and more specifically, to a method for reinforcing a rusted reinforced concrete column with FRP reinforcement and mesh. Background Technology

[0002] In nearshore areas, the high temperatures, high salinity, and strong winds of the marine environment pose significant challenges to the durability of reinforced concrete structures, with steel corrosion being the most prominent issue. When steel bars corrode, their cross-sectional area decreases, reducing their strength. Simultaneously, the concrete cover expands and cracks due to the expansion forces generated by corrosion, and the bond between the steel bars and concrete weakens. These factors significantly reduce the mechanical properties of reinforced concrete components, threatening the reliability of the entire structure. Reinforced concrete columns (piers), as crucial load-bearing and lateral force-resisting components in building and bridge structures, can have their overall load-bearing capacity and reliability significantly improved through appropriate and effective reinforcement methods, allowing them to better fulfill their function.

[0003] Traditional methods for strengthening reinforced concrete structures include increasing the cross-section, steel encasing, and bonding FRP mesh. Increasing the cross-section can effectively improve the load-bearing capacity of reinforced concrete columns, but it also increases the self-weight and stiffness of the members, making the structure more susceptible to seismic forces and negatively impacting seismic performance. Steel encasing effectively improves the load-bearing capacity of reinforced concrete columns by encasing them in steel plates, but in harsh environments, the outer steel plates are prone to corrosion, affecting the overall durability of the structure. Wrapping reinforced concrete with FRP fabric can improve the durability of reinforced concrete structures and enhance their load-bearing and deformation capacity by applying lateral constraints to the column cross-section, but the improvement is limited.

[0004] In view of this, the applicant hereby submits this application after studying the existing technology. Summary of the Invention

[0005] The present invention provides a corrosion-resistant reinforced concrete column reinforced with FRP reinforcement and mesh, and a reinforcement method thereof, which aims to improve at least one of the above-mentioned technical problems.

[0006] To solve the above-mentioned technical problems, the present invention provides an FRP-reinforced reinforced concrete column reinforced with mesh, comprising:

[0007] A concrete column having a section to be reinforced and corroded reinforcing steel exposed after the concrete cover of the section to be reinforced has been removed.

[0008] An FRP reinforcement-mesh bonding layer is formed by bonding FRP reinforcement bars and FRP mesh. The FRP reinforcement bars extend longitudinally and are evenly distributed inside the FRP mesh. The FRP reinforcement-mesh bonding layer is wrapped around the outside of the part to be reinforced after the concrete protective layer has been removed, and is used to provide longitudinal reinforcement and lateral restraint to reinforce the internal concrete of the part to be reinforced.

[0009] Several fasteners are driven at intervals into the core concrete of the concrete column along the length of the FRP reinforcement strips to fix the FRP reinforcement-mesh bonding layer.

[0010] Ultra-high performance concrete is filled on both the inner and outer sides of the FRP reinforcement-mesh bonding layer, so that the FRP reinforcement-mesh bonding layer is bonded to the reinforced concrete column, thereby repairing the removed concrete protective layer and restoring the cross-section of the concrete column to its original size.

[0011] As a further optimization, the FRP mesh is an orthogonal mesh with a thickness of 3-10mm and a mesh size of 10mm-150mm.

[0012] As a further optimization, the FRP ribs and the FRP mesh are any one of glass fiber, carbon fiber, aramid fiber or basalt fiber composite materials.

[0013] As a further optimization, the spacing between the plurality of fasteners is 3-5 times the grid size.

[0014] As a further optimization, the coarse aggregate diameter of the ultra-high performance concrete is 10mm-15mm.

[0015] As a further optimization, the parameters of the FRP reinforcement bar are calculated through the following steps:

[0016] Calculate the corrosion rate of corroded steel bars:

[0017]

[0018] In the formula, For corrosion rate, The quality loss is due to the corrosion of the reinforcing steel. It refers to the quality of uncorroded reinforcing bars, where reinforcing bars refer to longitudinal bars or stirrups;

[0019] The strength loss is determined based on the corrosion rate of the longitudinal reinforcement:

[0020]

[0021] in, It is a loss of longitudinal reinforcement strength. It is the yield strength of the longitudinal reinforcement. It is the original cross-sectional area of ​​the longitudinal reinforcement;

[0022] Calculate the cross-sectional area and quantity of the required additional FRP reinforcement bars:

[0023]

[0024]

[0025] in, It is the total cross-sectional area of ​​the FRP reinforcement bars. It is the yield strength of the FRP reinforcement bar. It refers to the number of FRP reinforcing bars. The diameter of the cross-section of the FRP reinforcement bar.

[0026] As a further optimization, the parameters of the FRP mesh are calculated through the following steps:

[0027] If the concrete column has a circular cross-section, the restraint loss of the corroded stirrups... for:

[0028]

[0029] in, The effective confinement coefficient of the core area concrete. This represents the volumetric stirrup ratio before the stirrups corroded. The yield strength of the stirrup before corrosion. This is a correction factor for the yield strength of the corroded stirrups;

[0030] Calculate the required FRP mesh size:

[0031]

[0032] in, For the number of FRP mesh layers, The ultimate tensile strength of the FRP mesh. The cross-sectional area of ​​a single branch of the FRP mesh. The center distance between adjacent FRP grids. The diameter of the circular concrete column;

[0033] If the concrete column has a rectangular cross-section, then the restraint loss of the corroded stirrups... for:

[0034]

[0035] in, The effective confinement coefficient of the core area concrete. and These represent the volumetric stirrup ratios in the x and y directions of the rectangular cross-section, respectively. and These are the lengths of the concrete in the core area of ​​the rectangular column in the x and y directions, respectively, where x is the longer side and y is the shorter side;

[0036] Calculate the required FRP mesh size:

[0037]

[0038]

[0039] in, Let be the diameter of the circumcircle of the rectangular section of the concrete column. and These are the length and width of the rectangular cross-section, respectively.

[0040] This application also provides a method for reinforcing a corroded reinforced concrete column reinforced with FRP reinforcement-mesh as described above, comprising the following steps:

[0041] S1: Utilize the rust expansion cracks formed on the surface of the concrete column by the corrosion of the steel bars, chisel away the concrete protective layer to completely expose the corroded steel bars, and remove the rust products on the surface.

[0042] S2: Clean the surface after chiseling and apply a layer of interface agent;

[0043] S3: Fix FRP bars at equal intervals inside the FRP mesh to form an FRP bar-mesh bonding layer. Then wrap and paste the FRP bar-mesh bonding layer around the concrete column where the concrete protective layer has been removed to provide longitudinal reinforcement and lateral restraint to strengthen the core area concrete of the area to be repaired.

[0044] S4: Fixing members are driven into the core area of ​​the concrete column at regular intervals along the longitudinal direction to fix the FRP reinforcement-mesh bonding layer.

[0045] S5: Inject ultra-high performance concrete into the inner and outer sides of the FRP reinforcement-mesh bonding layer to fill the removed concrete protective layer, so that the column cross-section of the concrete column is restored to its original size.

[0046] As a further optimization, in step S2, a layer of cement paste is applied to the concrete surface to act as an interface agent.

[0047] As a further optimization, in step S3, the FRP rib-mesh bonding layer is wound with at least 2 layers, and the extension length of the circumferential cut-off point of the FRP mesh should not be less than 200mm.

[0048] As a further optimization, in step S5, the coarse aggregate of the ultra-high performance concrete should fully penetrate the FRP reinforcement-mesh bonding layer during the pouring process.

[0049] By adopting the above technical solution, the present invention can achieve the following technical effects:

[0050] This application strengthens corroded reinforced concrete columns by combining FRP mesh with longitudinally extending FRP reinforcement bars. Firstly, the FRP mesh provides lateral restraint, compensating for restraint losses caused by stirrup corrosion, thereby improving the strength and deformation capacity of the internal concrete and effectively increasing the axial compression, bending, and shear resistance of the corroded reinforced concrete column. Secondly, the FRP reinforcement bars provide longitudinal reinforcement, compensating for strength losses caused by longitudinal reinforcement corrosion and improving the bending performance of the reinforced concrete column. The combined reinforcement-mesh mesh significantly improves the mechanical properties and durability of the reinforced concrete column, effectively slowing down the corrosion process. Furthermore, the mesh winding construction method is convenient and quick, adaptable to different component cross-sectional shapes, and does not alter the structural cross-sectional dimensions. Additionally, the FRP mesh can be fixed to the inside of the concrete cover using high-performance concrete, effectively avoiding environmental and durability problems caused by adhesives. These advantages make the combined reinforcement-mesh mesh an effective reinforcement method that improves the integrity and reliability of corroded reinforced concrete columns. Attached Figure Description

[0051] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0052] Figure 1 A structural schematic diagram of a corroded reinforced concrete column reinforced with FRP reinforcement and mesh.

[0053] Figure 2 A schematic diagram of the cross-section of a corroded reinforced concrete column reinforced with FRP reinforcement and mesh.

[0054] Markings in the diagram: 1-Concrete column; 2-Longitudinal reinforcement; 3-Stirrups; 4-FRP bars; 5-FRP mesh; 6-Ultra-high performance concrete; 7-Factors. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort 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 accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0056] Example 1

[0057] Depend on Figure 1 , Figure 2 As shown, this embodiment of the invention provides a rusted reinforced concrete column reinforced with FRP reinforcement and mesh, including a concrete column 1, FRP bars 4, FRP mesh 5, several fasteners 7, and ultra-high performance concrete 6.

[0058] The concrete column 1 has a part to be reinforced and the corroded steel bars exposed after the concrete protective layer of the part to be reinforced is removed; the concrete column 1 is mainly composed of concrete and a steel cage, the steel cage having longitudinal bars 2 and stirrups 3.

[0059] FRP reinforcing bars 4 are equidistantly arranged inside the FRP mesh 5 and extend longitudinally. The FRP reinforcing bars 4 and the FRP mesh 5 are bonded to form an FRP reinforcing bar-mesh bonding layer. The FRP reinforcing bar-mesh bonding layer is wrapped around the outside of the part to be reinforced after the concrete protective layer has been removed, and is used to provide longitudinal reinforcement and lateral restraint to reinforce the internal concrete of the part to be reinforced.

[0060] Several fasteners 7 are driven into the core area of ​​the concrete column 1 at intervals along the length of the FRP reinforcement 4 to fix the FRP reinforcement-mesh bonding layer; wherein, the interval between the fasteners 7 is preferably 3-5 times the size of the FRP mesh.

[0061] Ultra-high performance concrete 6 is filled on both the inner and outer sides of the FRP reinforcement-mesh bonding layer, so that the FRP reinforcement-mesh bonding layer and the concrete column have good bonding performance, ensuring that the two work together. At the same time, it can repair the removed concrete protective layer and restore the cross-section of the concrete column to its original size.

[0062] In this implementation, a reinforced concrete column is strengthened using a combination of reinforcement and mesh. FRP reinforcement bars 4 and FRP mesh 5 possess excellent corrosion resistance and high tensile strength. Wrapped around the outside of the concrete column 1, they provide lateral restraint to the internal concrete, compensating for the weakened lateral restraint caused by the corrosion of the stirrups. Meanwhile, FRP reinforcement bars 4 are primarily used to strengthen the longitudinal reinforcement 2. The combination of these two components enhances the strength and deformation capacity of the internal concrete, effectively increasing the axial compression, bending, and shear resistance of the corroded reinforced concrete column, thereby improving its load-bearing capacity and durability, ensuring it can withstand the design load and extending its service life. Repairing with ultra-high performance concrete can enhance the structure's strength and stiffness, seismic resistance, and improve durability.

[0063] Preferably, both the FRP reinforcing bars 4 and the FRP mesh 5 are selected from one of GFRP, CFRP, AFRP, and BFRP. The FRP mesh 5 is an orthogonal mesh with a thickness of 3-10 mm and a mesh size of 10 mm-150 mm. The FRP reinforcing bars 4 and the FRP mesh 5 have reliable adhesion, allowing the FRP mesh 5 to provide effective lateral restraint for the FRP reinforcing bars 4. The diameter of the FRP reinforcing bars 4 is selected as 6 mm or 8 mm, and the diameter and number of reinforcing bars are determined according to the corrosion rate of the longitudinal reinforcing bars 2.

[0064] Furthermore, the coarse aggregate of the ultra-high performance concrete 6 has a diameter of 10mm-15mm. During the filling process, the coarse aggregate fully penetrates the FRP reinforcement-mesh bonding layer to ensure that the FRP reinforcement-mesh bonding layer and the concrete protective layer are fully bonded.

[0065] The total cross-sectional area and number of FRP ribs, as well as the required FRP mesh size, have a significant impact on the reinforcement effect. If the total cross-sectional area and number of reinforcing FRP ribs are too small, or the FRP mesh size is too large, the reinforcement effect may not meet the requirements. Conversely, if the total cross-sectional area and number of reinforcing FRP ribs are too large, or the FRP mesh is too dense, it will lead to material waste and increased repair costs. To achieve the desired repair effect at a lower cost, in another preferred embodiment, the total cross-sectional area and number of FRP ribs, as well as the required FRP mesh size, are calculated through the following steps:

[0066] Calculate the corrosion rate of corroded steel bars:

[0067]

[0068] In the formula, For corrosion rate, The quality loss is due to the corrosion of the reinforcing steel. It refers to the quality of uncorroded reinforcing bars, where reinforcing bars refer to longitudinal bars or stirrups;

[0069] The strength loss is determined based on the corrosion rate of the longitudinal reinforcement:

[0070]

[0071] in, It is a loss of longitudinal reinforcement strength. It is the yield strength of the longitudinal reinforcement. It is the original cross-sectional area of ​​the longitudinal reinforcement;

[0072] Calculate the cross-sectional area and quantity of the required additional FRP reinforcement bars:

[0073]

[0074]

[0075] in, It is the total cross-sectional area of ​​the FRP reinforcement bars. It is the yield strength of the FRP reinforcement bar. It refers to the number of FRP reinforcing bars. The diameter of the cross-section of the FRP reinforcement bar;

[0076] Calculate the parameters of the FRP mesh:

[0077] (1) If the concrete column has a circular cross section, then the restraint loss of the corroded stirrups. for:

[0078]

[0079]

[0080]

[0081]

[0082]

[0083] in, and The values ​​represent the confinement strength of the core concrete by the uncorroded stirrups and the corroded stirrups, respectively. The effective confinement coefficient of the core area concrete. and The figures represent the volumetric stirrup ratios before and after stirrup corrosion. and The values ​​represent the yield strength of the stirrups before and after corrosion. The correction factor for the yield strength of the corroded stirrups is 0.5;

[0084] Calculate the required FRP mesh size:

[0085]

[0086] in, For the number of FRP mesh layers, The ultimate tensile strength of the FRP mesh. The cross-sectional area of ​​a single branch of the FRP mesh. The center distance between adjacent FRP grids. The diameter of the circular concrete column;

[0087] For concrete columns with circular cross-sections, the effective confinement coefficient of the core area concrete is... 1.0 is acceptable;

[0088] (2) If the concrete column has a rectangular cross section, then the restraint loss of the corroded stirrups. for:

[0089]

[0090] in, and Let X be the volumetric stirrup ratio in the x and y directions. and These are the lengths of the concrete in the core area of ​​the rectangular column in the x and y directions, respectively, where x is the longer side and y is the shorter side;

[0091] in, To effectively constrain the area, For the effective area of ​​the core area concrete, The longitudinal clear spacing of the reinforcing bars. This refers to the net spacing of the stirrups. This refers to the longitudinal reinforcement ratio.

[0092] Calculate the required FRP mesh size:

[0093]

[0094]

[0095] in, Let be the diameter of the circumcircle of the rectangular section of the concrete column. and These are the length and width of the rectangular cross-section, respectively.

[0096] For concrete columns with rectangular cross-sections, the effective confinement coefficient of the core concrete is... It can be calculated in the following way:

[0097]

[0098] This method calculates the total cross-sectional area and number of required FRP ribs, as well as the mesh size of the FRP grid, ensuring the reinforcement effect meets expectations while preventing material waste and facilitating cost control.

[0099] Example 2

[0100] This application also provides a method for reinforcing corroded reinforced concrete columns using the aforementioned FRP-mesh composite reinforcement, comprising the following steps:

[0101] S1: Utilize the rust expansion cracks formed on the surface of concrete column 1 by steel reinforcement corrosion, chisel away the concrete protective layer to completely expose the corroded steel reinforcement, and remove the rust products on the surface.

[0102] S2: Clean the surface after chiseling and apply a bonding agent;

[0103] S3: Fix the FRP bars 4 at equal intervals inside the FRP mesh 5 to form an FRP bar-mesh bonding layer. Then wrap and paste the FRP bar-mesh bonding layer around the concrete column where the concrete protective layer has been removed to provide longitudinal reinforcement and lateral restraint to strengthen the internal concrete of the area to be repaired.

[0104] S4: Fixing members 7 are driven into the core area of ​​the concrete column at certain intervals along the longitudinal direction to fix the FRP reinforcement-mesh bonding layer.

[0105] S5: Inject ultra-high performance concrete into both the inner and outer sides of the FRP reinforcement-mesh bonding layer to fill the removed concrete protective layer, restoring the column cross-section to its original dimensions. During the pouring process, the coarse aggregate of the ultra-high performance concrete should fully penetrate the FRP reinforcement-mesh bonding layer to ensure a thorough bond between the FRP reinforcement-mesh bonding layer and the concrete protective layer, guaranteeing that the two materials can work together after reinforcement.

[0106] FRP reinforcement bars 4 are mainly used to strengthen the longitudinal reinforcement bars 2, while FRP mesh 5 is mainly used to strengthen the stirrups 3. The selection of FRP reinforcement bars 4 and FRP mesh 5 is based on the strength loss of the longitudinal reinforcement bars 2 and the constraint loss of the stirrups 3. A higher corrosion rate results in greater losses, requiring a denser mesh and a larger reinforcement bar area. The total cross-sectional area and number of FRP reinforcement bars, as well as the required FRP mesh size, can be calculated using the steps described above.

[0107] The dimensions of the FRP ribs 4 can be set as needed, for example, in the range of 6-10mm in diameter, with an 8mm diameter FRP rib 4 being preferred. Once the diameter of the longitudinal ribs 4 is determined, the required length and number of longitudinal ribs 4 are also determined. The dimensions of the FRP mesh 5 can be set as needed, for example, in the range of 10-150mm, with 20mm and 50mm FRP mesh 5 being preferred.

[0108] In step S2, cement paste is preferred as the interface agent. A layer of cement paste can be applied to the surface of the concrete column to serve as the interface agent.

[0109] In step S3, the net spacing of the FRP ribs 4 in the horizontal direction should not be less than 4 times the maximum diameter of the FRP ribs 4; the FRP mesh 5 should be wound in at least 2 layers, and the extension length of the circumferential cut-off point of the mesh should not be less than 200mm.

[0110] In step S4, the fasteners 7 can be U-shaped expansion screws, which are driven in at regular intervals along the length of the FRP reinforcing bars 4 to constrain the FRP reinforcing bars and provide lateral support to the FRP mesh, preventing the reinforcing bars and mesh from falling off. The distance between adjacent fasteners 7 can be determined according to 3-5 times the mesh spacing, generally between 10cm and 20cm, to ensure that the FRP reinforcing bars 4 and FRP mesh 5 are fixed next to the corroded reinforcing bars.

[0111] Compared with the prior art, the main advantages of this invention include:

[0112] The use of a reinforced-mesh composite grid offers several advantages: First, it provides lateral restraint to the core concrete, effectively increasing the axial compression, bending, and shear strength of corroded reinforced concrete columns. Second, through longitudinal reinforcement, the FRP bars 4 compensate for strength loss caused by longitudinal reinforcement corrosion, thereby improving the axial compression and bending performance of the reinforced concrete column. Furthermore, the FRP mesh 5's winding construction method is convenient and quick, adaptable to different cross-sectional shapes, and does not alter the structural dimensions. Most importantly, the FRP reinforced-mesh composite layer is fixed to the inside of the concrete cover with high-performance concrete, effectively avoiding environmental and durability issues caused by adhesives, significantly improving the durability of the reinforced concrete column. Simultaneously, the ultra-high performance concrete 6 acts as a protective layer, more effectively protecting the reinforcing steel and enhancing durability. These advantages make the reinforced-mesh composite grid an effective reinforcement method, improving the overall performance and reliability of corroded reinforced concrete columns.

[0113] In summary, the FRP (Fiberglass Reinforced Plastic) reinforcement-mesh combination offers several advantages, including lateral restraint, longitudinal reinforcement, convenient winding construction, no change in cross-sectional dimensions, and improved durability. The reinforcement structure proposed in this example effectively compensates for performance losses caused by corrosion of longitudinal reinforcement and stirrups. Simultaneously, it improves the mechanical properties and durability of the reinforced concrete column without increasing the cross-sectional dimensions or altering the structure's dynamic characteristics. This reinforcement method enhances the overall performance of the structure while maintaining its original characteristics, demonstrating significant advantages.

[0114] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A corrosion-resistant reinforced concrete column reinforced with FRP (fiberglass reinforced plastic) reinforcement and mesh, characterized in that, include: A concrete column having a section to be reinforced and corroded reinforcing steel exposed after the concrete cover of the section to be reinforced has been removed. An FRP reinforcement-mesh bonding layer is formed by bonding FRP reinforcement bars and FRP mesh. The FRP reinforcement bars extend longitudinally and are evenly distributed inside the FRP mesh. The FRP reinforcement-mesh bonding layer is wrapped around the outside of the part to be reinforced after the concrete protective layer has been removed, and is used to provide longitudinal reinforcement and lateral restraint to reinforce the internal concrete of the part to be reinforced. Several fasteners are driven at intervals into the core concrete of the concrete column along the length of the FRP reinforcement strips to fix the FRP reinforcement-mesh bonding layer. Ultra-high performance concrete is filled on both the inner and outer sides of the FRP reinforcement-mesh bonding layer, so that the FRP reinforcement-mesh bonding layer is bonded to the concrete column, repairing the removed concrete protective layer and restoring the cross-section of the concrete column to its original size. The parameters of the FRP reinforcement bar are calculated through the following steps: Calculate the corrosion rate of corroded steel bars: In the formula, For corrosion rate, The quality loss is due to the corrosion of the reinforcing steel. It refers to the quality of uncorroded reinforcing bars, where reinforcing bars refer to longitudinal bars or stirrups; The strength loss is determined based on the corrosion rate of the longitudinal reinforcement: in, It is a loss of longitudinal reinforcement strength. It is the yield strength of the longitudinal reinforcement. It is the original cross-sectional area of ​​the longitudinal reinforcement; Calculate the cross-sectional area and quantity of the required additional FRP reinforcement bars: in, It is the total cross-sectional area of ​​the FRP reinforcement bars. It is the yield strength of the FRP reinforcement bar. It refers to the number of FRP reinforcing bars. The diameter of the cross-section of the FRP reinforcement bar; The parameters of the FRP mesh are calculated through the following steps: If the concrete column has a circular cross-section, the restraint loss of the corroded stirrups... for: in, The effective confinement coefficient of the core area concrete. This represents the volumetric stirrup ratio before the stirrups corroded. The yield strength of the stirrup before corrosion. This is a correction factor for the yield strength of the corroded stirrups; Calculate the mesh parameters of the required FRP mesh: in, For the number of FRP mesh layers, The ultimate tensile strength of the FRP mesh. The cross-sectional area of ​​a single branch of the FRP mesh. The center distance between adjacent FRP grids. The diameter of the circular concrete column; If the concrete column has a rectangular cross-section, then the restraint loss of the corroded stirrups... for: in, and These represent the volumetric stirrup ratios in the x and y directions of the rectangular cross-section, respectively. and Let x and y be the lengths of the concrete in the core area of ​​the rectangular column in the x and y directions, respectively, where x is the longer side and y is the shorter side; Calculate the required FRP mesh size: in, Let be the diameter of the circumcircle of the rectangular section of the concrete column. and These are the length and width of the rectangular cross-section, respectively.

2. The FRP-reinforced reinforced concrete column reinforced with mesh as described in claim 1, characterized in that... The FRP mesh is an orthogonal mesh with a thickness of 3-10mm and a mesh size of 10mm-150mm.

3. The FRP-reinforced reinforced concrete column reinforced with mesh as described in claim 1, characterized in that... The FRP ribs and the FRP mesh are any one of glass fiber, carbon fiber, aramid fiber or basalt fiber composite materials.

4. A corrosion-resistant reinforced concrete column reinforced with FRP reinforcement and mesh as described in claim 1, characterized in that... The spacing between the aforementioned fasteners is 3-5 times the grid size.

5. A corrosion-resistant reinforced concrete column reinforced with FRP reinforcement and mesh as described in claim 1, characterized in that... The coarse aggregate diameter of the ultra-high performance concrete is 10mm-15mm.

6. A method for reinforcing a corroded reinforced concrete column reinforced with FRP reinforcement-mesh as described in any one of claims 1-5, characterized in that... It includes the following steps: S1: Utilize the rust expansion cracks formed on the surface of the concrete column by the corrosion of the steel bars, chisel away the concrete protective layer to completely expose the corroded steel bars, and remove the rust products on the surface. S2: Clean the surface after chiseling and apply a layer of interface agent; S3: Fix FRP bars at equal intervals inside the FRP mesh to form an FRP bar-mesh bonding layer. Then wrap and paste the FRP bar-mesh bonding layer around the concrete column where the concrete protective layer has been removed to provide longitudinal reinforcement and lateral restraint to strengthen the core area concrete of the area to be repaired. S4: Fixing members are driven into the core area of ​​the concrete column at regular intervals along the longitudinal direction to fix the FRP reinforcement-mesh bonding layer. S5: Inject ultra-high performance concrete into the inner and outer sides of the FRP reinforcement-mesh bonding layer to fill the removed concrete protective layer, so that the column cross-section of the concrete column is restored to its original size.

7. The reinforcement method according to claim 6, characterized in that... In step S3, the FRP rib-mesh bonding layer is wound with at least 2 layers, and the extension length of the circumferential cut-off point of the FRP mesh should not be less than 200mm.

8. The reinforcement method according to claim 7, characterized in that... In step S5, during the pouring process of the ultra-high performance concrete, the coarse aggregate should fully penetrate the FRP reinforcement-mesh bonding layer.

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