Composite reinforcing method and device for improving anti-seismic property of rusted steel pipe joint

Abstract

The invention discloses a composite reinforcing method and device for improving the anti-seismic property of a rusted steel pipe joint, and relates to the field of rusted steel pipe joint reinforcement. A grouting opening is formed in a main pipe end opening of a rusted steel pipe, and reinforcing slurry is injected into the rusted steel pipe through the grouting opening; after the reinforcing slurry injected into the rusted steel pipe is vibrated, standing, curing and solidifying are conducted, and a grouting reinforcing body is formed; scribing and cutting the CFRP cloth according to the size of the rusted steel pipe; cleaning the surface of the rusted steel pipe; carbon fiber glue is smeared on the surface of the cleaned rusted steel pipe, and CFRP cloth is pasted on the surface of the rusted steel pipe smeared with the carbon fiber glue; according to the preset number of layers, a layer of carbon fiber glue and a layer of CFRP cloth are pasted; and a layer of structural adhesive is brushed on the CFRP cloth on the outermost layer, standing and maintenance are conducted, and composite reinforcement for improving the anti-seismic property of the rusted steel pipe joint is completed. And the UHPC-CFRP and the rusted steel pipe joint have a good cooperative working mechanism, so that the rigidity and the bearing capacity of the rusted steel pipe joint are improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of rusted steel pipe joint reinforcement, and particularly relates to a composite reinforcement method and device for improving the seismic performance of a rusted steel pipe joint. BACKGROUND

[0002] Steel pipe structures are widely used in various public and civil infrastructure projects due to their superior mechanical properties, economical material saving and other advantages. However, a large number of steel pipe structures serving in typical corrosion environments such as the ocean, acid rain and industry have serious corrosion problems, resulting in huge economic losses.

[0003] In addition, under the action of an earthquake, a steel structure joint will undergo local buckling, causing degradation of the bearing capacity and stiffness, and significantly affecting the overall performance of the structure. Corrosion damage will exacerbate the damage degradation behavior of the steel structure joint under the action of an earthquake, especially the presence of surface rust pits, which will further cause stress concentration, reduce the mechanical properties of the steel and exacerbate the local buckling behavior of the joint, thereby increasing the risk of structure collapse and even causing catastrophic accidents, resulting in huge economic losses and social impact. Therefore, it is of great practical significance to propose a reinforcement method for improving the seismic performance of a rusted steel pipe joint.

[0004] The existing research on methods for improving the seismic performance of steel pipe joints is almost blank, and most of the reinforcement method researches mainly focus on the bearing capacity of steel pipe joints. For example, the Chinese patent application with the publication number CN114658255A discloses a saddle reinforcement structure for a K-shaped intersecting joint, which reinforces the steel pipe joint by welding a steel plate outside the steel pipe intersecting joint; however, the thermal stress generated by the welded steel plate will change the properties of the steel in the joint area, causing new stress concentration and residual deformation; at the same time, the Chinese patent application with the publication number CN104233964B discloses a CFRP cloth reinforcement structure for a steel pipe intersecting joint of a steel truss bridge, which can reinforce the steel pipe joint, but the pasting of CFRP (Carbon Fiber Reinforced Polymer) cloth can only improve the tensile performance of the joint, and cannot avoid the crushing of the joint area.

[0005] In addition, the existing technology also discloses internal reinforcement methods for steel pipes, such as the method of filling solid concrete inside the steel pipe joint proposed by [Lan Weifei. Static performance research on branch pipe compression of circular steel pipe concrete T-shaped intersecting joint [D]. Sichuan University, 2022.]. The solid concrete filling method for reinforcing the steel pipe joint has the following disadvantages: difficult construction, long construction period, need for large equipment, significantly increased self-weight, limited seismic improvement and poor ductility, difficult detection in the later period, inconvenient maintenance and modification, and obvious disadvantages in construction, performance and maintenance. SUMMARY

[0006] The present application aims at improving the seismic performance of a corroded steel pipe joint.

[0007] To achieve the above-mentioned purpose, the present application adopts the following technical solutions: In a first aspect, the present application provides a composite reinforcement method for improving the seismic performance of a corroded steel pipe joint, comprising the following steps: A grouting port is opened at the end of the main pipe of the corroded steel pipe, and a reinforcing slurry is injected into the corroded steel pipe through the grouting port; After the reinforcing slurry injected into the corroded steel pipe is vibrated, it is left to cure and solidify into a grouting reinforced body; The surface of the corroded steel pipe is cleaned; Carbon fiber glue is applied to the surface of the cleaned corroded steel pipe, and CFRP cloth is pasted on the surface of the corroded steel pipe after the carbon fiber glue is applied; According to the preset number of layers, the pasting method of one layer of carbon fiber glue and one layer of CFRP cloth is adopted for pasting; After pasting is completed, a layer of structural glue is brushed on the outermost CFRP cloth, and left to cure, thereby completing the composite reinforcement for improving the seismic performance of the corroded steel pipe joint.

[0008] Further, the diameter of the grouting port is 0.5-1.0 times the diameter of the corroded steel pipe.

[0009] Further, the reinforcing slurry is prepared by reinforcing materials, and the reinforcing materials include UHPC, water reducing agent, steel fiber and water. The reinforcing materials are stirred in a mixer to form the reinforcing slurry. Specifically, the UHPC is first poured into the mixer for stirring, then the water reducing agent and water are poured into the mixer at the same time for stirring, the steel fiber is added after the material is fluidized, and the stirring is continued until the steel fiber is fully mixed with the material to obtain the reinforcing slurry.

[0010] Further, the carbon fiber glue is an epoxy resin impregnated glue. The preparation method of the carbon fiber glue is specifically as follows: a plurality of epoxy resin impregnated glues are mixed to obtain the carbon fiber glue.

[0011] Further, pasting the CFRP cloth on the surface of the corroded steel pipe after applying the carbon fiber glue is specifically as follows: the CFRP cloth is pasted and covered on the surface of the corroded steel pipe after applying the carbon fiber glue, and a scraper is used to scrape along the fiber direction to discharge the internal bubbles and press and scrape the edge to supplement the carbon fiber glue.

[0012] Further, when pasting the CFRP cloth on the surface of the corroded steel pipe after applying the carbon fiber glue, the CFRP cloth is preset with different lap lengths according to different pasting angles, which are specifically as follows: The fiber direction of the odd-numbered layer of CFRP cloth is parallel to the main pipe axis of the corroded steel pipe, and the lap length of the odd-numbered layer of CFRP cloth is the first preset length for pasting. The fiber direction of the even layer of CFRP cloth is perpendicular to the main pipe axis of the corroded steel pipe, and the overlap length of the even layer of CFRP cloth is the second preset length for pasting; The second preset length is smaller than the first preset length.

[0013] Further, the vibration of the injected reinforcing slurry in the corroded steel pipe is specifically that the vibration rod is inserted into the inside of the corroded steel pipe into which the reinforcing slurry has been injected to vibrate, and the vibration rod is taken out after the vibration is completed.

[0014] Further, the surface cleaning of the corroded steel pipe includes that the rust on the surface of the corroded steel pipe is polished, and the surface of the corroded steel pipe after polishing is wiped with alcohol.

[0015] Further, the carbon fiber glue is applied on the surface of the corroded steel pipe after cleaning, and specifically, the carbon fiber glue is applied on the surface of the corroded steel pipe by using a roller.

[0016] In the second aspect, the application provides a composite reinforcing device for improving the seismic performance of a corroded steel pipe joint, and adopts a composite reinforcing method for improving the seismic performance of the corroded steel pipe joint, which includes a grouting reinforcing body, a carbon fiber glue layer, a CFRP cloth layer, and a structural glue layer.

[0017] Compared with the prior art, the application has the following beneficial technical effects: The composite reinforcing method for improving the seismic performance of the corroded steel pipe joint includes the following steps: an injection port is arranged at the port of the main pipe of the corroded steel pipe, reinforcing slurry is injected from the injection port, and the reinforcing slurry is left to solidify in the corroded steel pipe to form a grouting reinforcing body; and the carbon fiber reinforced polymer (CFRP) cloth is externally attached to the surface of the main pipe of the corroded steel pipe. The seismic performance and ductility of the reinforced corroded steel pipe joint are significantly improved, the stiffness and bearing capacity of the corroded steel pipe joint are improved, and thus the corroded steel pipe joint has good mechanical properties under the action of an earthquake. The composite reinforcing method combines grouting reinforcement and external CFRP reinforcement, and the UHPC-CFRP (Ultra-High Performance Concrete - Carbon Fiber Reinforced Polymer) has a good synergistic working mechanism with the corroded steel pipe joint. The seismic performance and ductility of the reinforced corroded steel pipe joint are significantly improved, the stiffness and bearing capacity of the corroded steel pipe joint are improved, and thus the corroded steel pipe joint has good mechanical properties under the action of an earthquake. The seismic performance and ductility of the reinforced corroded steel pipe joint are significantly improved, the stiffness and bearing capacity of the corroded steel pipe joint are improved, and thus the corroded steel pipe joint has good mechanical properties under the action of an earthquake. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the present invention in any way. In addition, the shapes and proportional dimensions of the components in the drawings are only schematic and are used to help understand the present invention, and are not intended to specifically limit the shapes and proportional dimensions of the components of the present invention. In the drawings: Figure 1 This is a front view of a corroded steel pipe reinforced using a composite reinforcement method for improving the seismic performance of corroded steel pipe nodes according to the present invention.

[0019] Figure 2 A top view of a corroded steel pipe reinforced using a composite reinforcement method for improving the seismic performance of corroded steel pipe nodes according to the present invention.

[0020] Figure 3 A comparison diagram of the cyclic tension-compression hysteresis curves of the nodes of the corroded steel pipe reinforced by using the composite reinforcement method for improving the seismic performance of the corroded steel pipe node of the present invention and the unreinforced corroded steel pipe.

[0021] Figure 4 The present invention is a flow chart of a composite reinforcement method for improving the seismic performance of corroded steel pipe nodes.

[0022] Among them, 1 is the main pipe, 11 is the branch pipe, 2 is the CFRP cloth, and 3 is the grouting reinforcement body. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0024] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may be an element centered thereon. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an element centered thereon. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one skilled in the art to which this invention pertains. The terms used in this specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0026] It should be noted that the terms "first," "second," and the like in the description of the present invention and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to these processes, methods, products, or apparatus.

[0027] Example 1 See also Figure 4 A composite reinforcement method for improving the seismic performance of corroded steel pipe nodes comprises the following steps: A grouting port is opened at the main pipe 1 port of the corroded steel pipe, and the reinforcement slurry is injected into the corroded steel pipe through the grouting port; After vibrating the reinforcement slurry injected into the corroded steel pipe, it is left to stand for curing and solidification to form a grouting reinforcement body 3; Clean the surface of rusted steel pipe; Apply carbon fiber glue to the cleaned surface of the rusted steel pipe, and stick CFRP cloth 2 on the surface of the rusted steel pipe after applying carbon fiber glue; According to the preset number of layers, a layer of carbon fiber glue and a layer of CFRP cloth 2 are used for pasting; After pasting is completed, a layer of structural adhesive is brushed on the outermost layer of CFRP cloth 2 and allowed to stand for curing to complete the composite reinforcement for improving the seismic performance of the corroded steel pipe node.

[0028] In the aspect of grouting reinforcement, the grouting port is opened at the end of the rusted steel pipe main pipe 1 to inject reinforcing slurry, and the grouting reinforcement body 3 formed by solidification can fill the inside of the rusted steel pipe, make the structure more compact and complete, enhance the self-bearing capacity of the rusted steel pipe, and improve the mechanical properties. The CFRP cloth is a composite material composed of carbon fibers and a resin matrix. The carbon fibers serve as the reinforcing phase to provide high strength and high modulus; and the resin matrix serves as the matrix phase to bond the carbon fibers together and transfer the load. The CFRP cloth has high strength and high elastic modulus, and after being cut and pasted according to the size of the rusted steel pipe, it can effectively constrain the lateral deformation of the rusted steel pipe, improve the axial bearing capacity and bending stiffness, and has good corrosion resistance, thereby protecting the rusted steel pipe from further corrosion. During construction, the marking and cutting can accurately adapt to rusted steel pipes of different specifications, and the pasting method of one layer of cloth and one layer of glue is convenient and flexible, has low requirements for construction conditions, and has light self-weight without adding too much burden. The present embodiment combines the advantages of grouting and CFRP cloth reinforcement, and has internal and external synergistic effects, improves the structural properties from the inside, and enhances the constraint bearing capacity from the outside, which can more comprehensively and effectively improve the seismic performance of the rusted steel pipe joint, significantly enhance the structural safety and reliability, prolong the service life of the structure, reduce the frequency of maintenance and replacement, reduce the life cycle cost, and have good economic and social benefits.

[0029] Optionally, the carbon fiber glue adopts epoxy resin impregnated glue; and the preparation method of the carbon fiber glue is specifically as follows: a plurality of kinds of epoxy resin impregnated glue are mixed to obtain the carbon fiber glue. The performance customization is realized through component compounding, which can accurately adapt to the interface characteristics of the rusted steel pipe and the CFRP cloth, can enhance the adhesion to the surface of the rusted steel pipe by means of metal infiltration components, fill the rust pits, and avoid delamination, and can penetrate the fiber gap of the CFRP cloth through fiber infiltration components to ensure the close combination of glue-fiber to transfer strength.

[0030] Optionally, when the CFRP cloth 2 is pasted on the surface of the rusted steel pipe after the carbon fiber glue is applied, the CFRP cloth 2 is preset with different lap lengths according to different pasting angles, specifically: the fiber direction of the odd-numbered layer of CFRP cloth is parallel to the main pipe 1 axis of the rusted steel pipe, and the lap length of the odd-numbered layer of CFRP cloth is taken as the first preset length for pasting; the fiber direction of the even-numbered layer of CFRP cloth is perpendicular to the main pipe 1 axis of the rusted steel pipe, and the lap length of the even-numbered layer of CFRP cloth is taken as the second preset length for pasting; the second preset length is less than the first preset length.

[0031] While ensuring the reinforcement effect, the dual balance of directional reinforcement and construction optimization is realized, the core requirement of the rusted steel pipe reinforcement is to resist the axial tension (in the direction of the main pipe 1 axis) and the hoop stress (perpendicular to the axis), and more than 90% of the strength of the CFRP cloth 2 is concentrated in the fiber direction, and the design of the present embodiment can accurately align the strength direction of each layer of CFRP cloth with the stress direction of the rusted steel pipe: Odd layer (0°, parallel axis): the fiber direction is consistent with the axial stress of the corroded steel pipe, which specially strengthens the axial tensile / anti-deformation capacity of the corroded steel pipe (such as the risk of fracture of the corroded steel pipe under tension and the risk of buckling under pressure). At this time, a longer first preset length is used to avoid the tearing of the CFRP cloth from the lap joint under axial stress, ensuring the continuity and reliability of the axial reinforcement.

[0032] Even layer (90°, perpendicular axis): the fiber direction is consistent with the hoop stress of the corroded steel pipe, which specially strengthens the hoop anti-expansion / anti-cracking capacity of the steel pipe (such as the hoop tensile caused by the internal pressure of the corroded steel pipe and the insufficient hoop bearing capacity of the corroded pipe wall). Since the hoop stress is usually smaller than the axial stress, and the vertical direction lap joint has less impact on the overall strength, a shorter second preset length can meet the demand without excessive redundancy. Reducing the waste consumption of CFRP cloth reduces the overall material cost. The longer the lap length of the CFRP cloth, the larger the range that needs to be aligned and compacted, especially when the corroded steel pipe is pasted on the curved surface, and the long lap joint is easy to cause interlayer misalignment and bubble residue. Short lap of even layer can simplify the operation process, improve construction efficiency, and reduce the interlayer bonding hazards caused by long lap.

[0033] Odd layer long lap joint ensures the strength continuity of the axial main stress direction, and even layer short lap joint assists in hoop reinforcement, forming a three-dimensional stress system in the axial-hoop direction, making the overall bearing of the steel pipe more balanced.

[0034] Example two A composite reinforcement device for improving the seismic performance of a corroded steel pipe joint, which adopts the composite reinforcement method for improving the seismic performance of a corroded steel pipe joint in example one, comprising a grouting reinforcement body, a carbon fiber glue layer, a CFRP cloth layer and a structural adhesive layer. The carbon fiber glue layer and the CFRP cloth layer are pasted according to the preset number of layers in a pasting mode of one layer of carbon fiber glue and one layer of CFRP cloth.

[0035] The embodiment adopts a composite reinforcement method to reinforce the corroded steel pipe joint. In terms of structural performance, grouting fills the inside of the corroded steel pipe to form a dense reinforcement body, greatly improving the bearing capacity of the corroded steel pipe itself; the pasted CFRP cloth 2 externally restrains the deformation of the corroded steel pipe, further improves its compression and bending resistance, and improves its seismic performance, and can also optimize stress distribution, avoid damage caused by excessive local stress, and improve overall stability and reliability. In terms of durability, the CFRP cloth 2 has strong corrosion resistance, prevents external erosion, prolongs the service life of the corroded steel pipe, enables it to maintain good performance in harsh environments, and reduces maintenance frequency and cost. The construction convenience is outstanding, the grouting and CFRP cloth 2 pasting operation is simple and flexible, the skill requirement for construction personnel is not high, and the construction speed is fast, without the need for complex equipment and large machinery, which can shorten the construction period, reduce the impact on the surrounding environment, and is also suitable for reinforcing corroded steel pipe joints of different specifications, shapes and corrosion degrees. The economic and social benefits are significant, which improves the seismic and durability of the joint, reduces the cost of post-disaster repair and reconstruction, and ensures social safety; the use of environmentally friendly materials reduces waste generation and is in line with the concept of sustainable development, which reduces the life cycle cost in the long run and has both economic and social values.

[0036] Embodiment three A composite reinforcement method for improving the seismic performance of a corroded steel pipe joint, referring to Figure 1 and Figure 2 , a schematic diagram of the composite reinforcement of the corroded steel pipe joint, specifically comprising the following steps: S1. A grouting port is opened at the upper end of the corroded steel pipe main pipe 1.

[0037] Specifically, the diameter of the steel pipe main pipe 1 that needs to be reinforced is measured to obtain the diameter data of the main pipe 1, the diameter of the grouting port is 0.5-1.0 times the diameter data of the main pipe 1, and the diameter data of the grouting port is obtained, and the grouting port is opened at the upper end of the corroded steel pipe main pipe 1. S2. Prepare the reinforcement slurry according to the quality ratio of different reinforcement materials, and pour the prepared reinforcement materials into the mixer for stirring.

[0038] Specifically, UHPC uses a finished product with a standard mass of 50 kg prepared according to a certain ratio, and is prepared according to the mass ratio UHPC: water reducing agent: steel fiber: water = 2150: 18-20: 165: 170. Pour the prepared reinforcement materials into the mixer for stirring. First, pour the powder-like UHPC into the mixer and stir for 2 minutes, then pour the water reducing agent and water into the mixer at the same time, and then add the steel fiber after the material is fluidized. Continue to stir until the steel fiber is fully mixed with the material.

[0039] S3. Inject the prepared reinforcement slurry through the grouting port, and insert the vibrating rod into the inside of the corroded steel pipe filled with the reinforcement slurry for vibration. S4, solidify into grouting reinforcement body 3 by curing; S5, according to the size of the corroded steel pipe, design the size of the paste, and cut the CFRP cloth 2 by marking; S6, after cutting, polish the surface rust of the corroded steel pipe, and wipe it with alcohol to prevent dust on the surface of the corroded steel pipe from affecting the quality of the paste; Specifically, the surface rust of the corroded steel pipe is polished with sandpaper, after polishing, alcohol is sprayed on the surface of the corroded steel pipe for wiping, after the alcohol evaporates, the wiping is repeated again, and the step is repeated three times.

[0040] S7, after the surface of the corroded steel pipe is cleaned, the carbon fiber glue is prepared, the carbon fiber glue is taken by the roller to coat on the surface of the corroded steel pipe, and the thickness of the glue layer on the surface of the corroded steel pipe is ensured to be uniform; Specifically, the carbon fiber glue is prepared according to the proportion, the two kinds of epoxy resin impregnated glue are mixed according to the mass ratio of 2:1, in this embodiment, Nanjing Shengsheng carbon fiber impregnated glue A and Nanjing Shengsheng carbon fiber impregnated glue B are mixed according to the mass ratio of 2:1, and during the preparation process, the two kinds of epoxy resin impregnated glue should be mixed quickly to prevent the two kinds of epoxy resin impregnated glue from being deteriorated due to contact with air, thereby affecting the bonding strength. In addition, appropriate protective measures should be taken when preparing the carbon fiber glue to avoid contact with the skin. After preparation, the carbon fiber glue is taken by the roller to coat on the surface of the corroded steel pipe uniformly, and the thickness of the glue layer on the surface of the corroded steel pipe is ensured to be uniform.

[0041] S8, wrap the CFRP cloth 2 on the surface of the corroded steel pipe, and at the same time, use a scraper to scrape along the fiber direction to discharge the internal bubbles, and supplement the glue to press and scrape the CFRP cloth 2 that is raised at the edge; Specifically, the first layer of CFRP cloth is pasted, which is pasted and wrapped according to the fiber direction parallel to the axis of the main pipe 1, that is, the angle is 0°, the lap length between the CFRP cloths is 150mm, after wrapping, the scraper is used to scrape along the fiber direction to discharge the internal bubbles, and the CFRP cloth is fully attached to the carbon fiber glue, and the CFRP cloth 2 that is raised at the edge is supplemented with glue and pressed and scraped.

[0042] S9, paste according to the designed number of layers, and follow the pasting mode of one layer of CFRP cloth and one layer of carbon fiber glue, then according to different paste angles, the lap length of the CFRP cloth 2 is set to different lap lengths according to the design requirements; Specifically, then use the roller to dip the carbon fiber glue on the first layer of CFRP cloth to evenly coat the glue, and the second layer of CFRP cloth is pasted and wrapped according to the fiber direction perpendicular to the axis direction of the main pipe 1, that is, the angle is 90°, and the lap length between the CFRP cloth and the CFRP cloth is 50mm, and the same reason is used to scrape the flat treatment, and then the steps of S8 and S9 are repeated to paste the third and fourth layers of CFRP cloth, and the pasting mode of one layer of CFRP cloth and one layer of carbon fiber glue is followed.

[0043] S10, after pasting, brush a layer of structural glue on the outermost CFRP cloth, and stand for maintenance; complete the composite reinforcement of the corrosion steel pipe node to improve the seismic performance; Specifically, after pasting the four layers of carbon fiber cloth, a layer of structural glue is brushed on the outermost CFRP cloth by using a roller, and the structural glue has a certain protective effect on the stress of the CFRP cloth, and finally the corrosion steel pipe is placed and maintained.

[0044] The quasi-static test is conducted on the corrosion steel pipe node reinforced by the above-mentioned embodiment, and the following results are obtained Figure 3 The node cycle tension-compression hysteresis curve comparison chart of the corrosion steel pipe reinforced by the composite reinforcement method for improving the seismic performance of the corrosion steel pipe node and the corrosion steel pipe without reinforcement is shown in the figure, the solid line is the hysteresis curve of the corrosion steel pipe without reinforcement, and the dashed line is the hysteresis curve of the corrosion steel pipe reinforced by the composite reinforcement method for improving the seismic performance of the corrosion steel pipe node. As can be seen from the figure, the hysteresis loop area of the corrosion steel pipe reinforced by the composite reinforcement method for improving the seismic performance of the corrosion steel pipe node is obviously larger than that of the corrosion steel pipe without reinforcement, and the ultimate bearing capacity and ultimate displacement are higher than those of the corrosion steel pipe without reinforcement. This shows that the reinforcement significantly improves the energy dissipation capacity and stiffness of the corrosion steel pipe.

[0045] In summary, the method improves the seismic performance of the corrosion steel pipe node by the composite reinforcement method of grouting in the pipe and pasting CFRP cloth outside the pipe, and the applicable objects include various types of steel pipe nodes, such as T-type node, K-type node, etc.

[0046] Many embodiments and many applications other than those provided in the foregoing description will be apparent to those skilled in the art from the foregoing description. Thus, the scope of the present teachings should not be determined from the foregoing description, but instead should be determined from the following claims as well as equivalents to the claims. The disclosures of all articles and references, including patent applications and publications, are incorporated by reference for all purposes. Any aspects of the subject matter disclosed herein that are not recited in the claims are hereby abandoned. The summary of the application is not intended to limit the scope of the application.

[0047] The above is a further detailed description of the present application, which cannot be deemed to limit the specific embodiments of the present application to the above, and for those skilled in the art to which the present application belongs, without departing from the concept of the present application, a number of simple deductions or substitutions can be made, which shall be deemed to belong to the determined protection scope of the present application.

Claims

1. A composite reinforcement method for improving the seismic performance of a corroded steel pipe joint, characterized in that, The method comprises the following steps: A grouting port is opened at a main pipe end of the corroded steel pipe, and a reinforcing slurry is injected into the corroded steel pipe through the grouting port; After the reinforcing slurry injected into the corroded steel pipe is vibrated and compacted, the reinforcing slurry is cured to form a grouting reinforcing body; The surface of the corroded steel pipe is cleaned; Carbon fiber glue is applied to the surface of the cleaned corroded steel pipe, and CFRP cloth is pasted on the surface of the corroded steel pipe after the carbon fiber glue is applied; The CFRP cloth is pasted according to a preset number of layers, and the CFRP cloth is pasted in a manner of one layer of carbon fiber glue and one layer of CFRP cloth; After the pasting is completed, a layer of structural glue is brushed on the outermost layer of CFRP cloth, and the structural glue is cured, thereby completing the composite reinforcement for improving the seismic performance of the corroded steel pipe joint.

2. The composite reinforcement method for improving the seismic performance of a corroded steel pipe joint according to claim 1, characterized in that, The diameter of the grouting port is 0.5-1.0 times the diameter of the corroded steel pipe.

3. The composite reinforcement method for improving the seismic performance of a corroded steel pipe joint according to claim 1, characterized in that, The reinforcing slurry is prepared by using reinforcing materials, and the reinforcing materials comprise UHPC, water reducing agent, steel fiber and water. The reinforcing materials are stirred in a stirrer to form the reinforcing slurry. Specifically, the UHPC is first poured into the stirrer for stirring, and then the water reducing agent and water are poured into the stirrer for stirring. After the materials are fluidized, the steel fiber is added, and the stirring is continuously performed until the steel fiber is fully mixed with the materials, thereby obtaining the reinforcing slurry.

4. The composite reinforcement method for improving the seismic performance of a corroded steel pipe joint according to claim 1, characterized in that, The carbon fiber glue is prepared by using epoxy resin impregnated glue.

5. The composite reinforcement method for improving the seismic performance of a corroded steel pipe joint according to claim 1, characterized in that, The CFRP cloth is pasted on the surface of the corroded steel pipe after the carbon fiber glue is applied. Specifically, the CFRP cloth is pasted on the surface of the corroded steel pipe after the carbon fiber glue is applied, and a scraper is used to scrape the CFRP cloth along the fiber direction to remove the internal bubbles and press and scrape the edge to supplement the carbon fiber glue.

6. The composite reinforcement method for improving the seismic performance of a corroded steel tubular joint according to claim 1, characterized in that, When the CFRP cloth is pasted on the surface of the corroded steel pipe after the carbon fiber glue is applied, the CFRP cloth has different lap lengths according to different pasting angles. Specifically, The fiber direction of the odd-numbered layer of CFRP cloth is parallel to the main pipe axis of the corroded steel pipe, and the lap length of the odd-numbered layer of CFRP cloth is the first preset length. The fiber direction of the even-numbered layer of CFRP cloth is perpendicular to the main pipe axis of the corroded steel pipe, and the lap length of the even-numbered layer of CFRP cloth is the second preset length. The second preset length is smaller than the first preset length.

7. The composite reinforcement method for improving the seismic performance of a corroded steel tubular joint according to claim 1, characterized in that, The reinforcing slurry injected into the corroded steel pipe is vibrated by inserting a vibrating rod into the interior of the corroded steel pipe to which the reinforcing slurry is injected, and the vibrating rod is removed after the vibration is completed.

8. The composite reinforcement method for improving the seismic performance of a corroded steel pipe joint according to claim 1, characterized in that, The surface of the corroded steel pipe is cleaned by polishing the floating rust on the surface of the corroded steel pipe and wiping the polished surface of the corroded steel pipe with alcohol.

9. The composite reinforcement method for improving the seismic performance of a corroded steel tubular joint according to claim 1, wherein The carbon fiber glue is applied to the surface of the cleaned corroded steel pipe by using a roller to dip the carbon fiber glue.

10. A composite reinforcement device for improving the seismic performance of corroded steel pipe nodes, characterized in that: The composite reinforcement method for improving the seismic performance of the corroded steel pipe joint comprises a grouting reinforcing body, a carbon fiber glue layer, a CFRP cloth layer and a structural glue layer. The carbon fiber glue layer and the CFRP cloth layer are pasted in a manner of one layer of carbon fiber glue and one layer of CFRP cloth according to a preset number of layers.

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