FRP Fabric Prestressed Reinforcement Device and Its Construction Method

Abstract

The present invention discloses an FRP cloth prestressed reinforcement device and a construction method thereof, wherein the FRP cloth prestressed reinforcement device comprises an FRP cloth and a winding tensioning member for winding the FRP cloth, wherein both ends of the FRP cloth are respectively provided with a bonding anchoring area for connecting to a structural member, and the winding tensioning member is located between the two bonding anchoring areas. By rotatably installing the winding tensioning member on the structural member, the prestress of the FRP cloth is changed when the angle of the winding tensioning member is adjusted. The present invention can first paste and anchor the two ends of the FRP cloth and then tension it, without drilling or welding the original member. The operation is convenient and the cost is low, and it is particularly suitable for steel members that are not suitable for drilling holes. Through a specially designed winding tensioning member that can be installed later, the FRP cloth is wrapped, pre-tightened, and rotationally tensioned, thereby realizing tensioning, prestressing control and adjustment of the FRP cloth. The method is efficient and labor-saving, does not require special mechanical equipment, amplifies the elongation stroke of the FRP end, and has high promotion value.

Description

Technical Field

[0001] The present invention relates to the technical field of structural reinforcement, and in particular to an FRP cloth prestressed reinforcement device and a construction method thereof. Background Art

[0002] Prestressed fiber reinforced plastic (FRP) reinforcement is an efficient reinforcement method. In engineering practice, prestressed FRP plates are mostly used for reinforcement and are widely used in the reinforcement of large-span concrete beams, steel beams and other components. FRP cloth is soft in texture, lightweight, and has strong shape adaptability, making it more suitable for the reinforcement of small-scale and geometrically complex structural components. However, for small-scale structural components, the FRP cloth tensioning stroke is small, ordinary tensioning tooling is difficult to apply, prestressing is difficult to apply, and it is easy to lose. At the same time, traditional anchors are large in size, cumbersome in anchoring, and expensive. In addition, the synergistic force performance between the fiber bundles of the FRP cloth is poor, the size effect is obvious, and the strength utilization rate is low when directly subjected to tension. Summary of the Invention

[0003] To overcome the defects in the prior art, the present invention provides an FRP cloth prestressed reinforcement device and a construction method thereof, which can realize efficient tensioning, prestress control and adjustment of the FRP cloth. At the same time, it is efficient and labor-saving, does not require special mechanical equipment, and amplifies the elongation stroke of the FRP cloth end, which can further improve the control and adjustment of the FRP cloth prestress.

[0004] In order to achieve the above-mentioned object, the present invention provides an FRP cloth prestressed reinforcement device and a construction method thereof, comprising:

[0005] An FRP sheet and a wrapping tensioner for wrapping the FRP sheet, wherein both ends of the FRP sheet are provided with bonding anchoring areas for connecting to structural members, and the wrapping tensioner is located between the two bonding anchoring areas. By rotatably mounting the wrapping tensioner on the structural member, the prestress applied to the FRP sheet can be changed when the angle of the wrapping tensioner is adjusted.

[0006] Preferably, the winding tensioning member includes an abutting end that contacts the structural member and is rotatably arranged on the structural member, and an adjusting end fixedly connected to the abutting end, the adjusting end is located on the side farther from the center line of the structural member relative to the abutting end, and an adjusting component is connected to the structural member so that the distance between the adjusting end and the structural member can be adjusted.

[0007] Preferably, a mounting groove for winding the FRP cloth is provided on a side of the winding tensioning member close to the abutting end, and an opening is connected on the side of the mounting groove close to the abutting end for the FRP cloth to pass through and be embedded in the mounting groove.

[0008] Preferably, an extension rod is installed on the side of the winding and tensioning member away from the structural member, and a first internal threaded hole is correspondingly opened on the side of the winding and tensioning member opposite to the installation groove and on the extension rod. The first internal threaded hole is screwed with a first screw for cooperating with a first nut to connect the extension rod to the winding and tensioning member.

[0009] Preferably, it also includes an adjusting rod installed on the side of the winding and tensioning member away from the structural member, a second screw is installed on the adjusting rod, and a second internal threaded hole is correspondingly opened on the winding and tensioning member. The second screw is screwed into the second internal threaded hole and is used to cooperate with a second nut to connect the adjusting rod and the winding and tensioning member.

[0010] Preferably, the FRP cloth passes through and is wound between the winding and tensioning member and the adjusting rod.

[0011] Preferably, the adjustment assembly includes a tensioning screw installed on the structural member and connected to the adjustment end at one end away from the structural member, a fastening nut for cooperating with the tensioning screw to connect the adjustment end to the tensioning screw, and the adjustment end is provided with a first through hole for the tensioning screw to pass through.

[0012] Preferably, the first through hole is an oblong hole, and a moving space is formed in the oblong hole for the tensioning screw to move along the length direction of the oblong hole.

[0013] Preferably, two ends of the FRP cloth are respectively connected to two sides of the structural member, and two winding and tensioning members are respectively wound around the FRP cloth corresponding to two sides of the structural member.

[0014] A construction method for prestressed reinforcement using an FRP cloth prestressed reinforcement device comprises the following steps:

[0015] The bonding anchoring areas at both ends of the FRP cloth are glued and anchored on the structural member to be reinforced, and a certain length of FRP cloth is reserved between the two bonding anchoring areas;

[0016] Installing a winding tensioning member on the structural member to be reinforced, wrapping the FRP sheet through the winding tensioning member, and pre-tightening the FRP sheet;

[0017] Installing an adjustment assembly on the winding tensioning member;

[0018] The angle between the winding tensioning member and the structural member to be reinforced is adjusted by adjusting the assembly so that the winding tensioning member fits close to the structural member to be reinforced, and prestressed tensioning is applied to the FRP cloth.

[0019] Due to the adoption of the above technical solution, the present invention has the following beneficial effects:

[0020] The FRP cloth prestressed reinforcement device and construction method of the present invention can achieve efficient tensioning and anchoring of the FRP cloth. After the interval pre-impregnation and curing treatment, the coordinated stress performance of the FRP cloth fiber bundles is improved, thereby achieving the beneficial effect of improving the strength utilization rate of the FRP cloth. At the same time, the non-pre-impregnated area can still be bent at will, retaining the lightness and shape adaptability of FRP. The two ends of the FRP cloth can be pasted and anchored first, and then tensioned, without the need to drill holes or weld the original components. The operation is convenient and the cost is low, and it is especially suitable for steel components that are not suitable for drilling holes. Through the specially designed post-installable winding and tensioning parts, the FRP cloth is wrapped, pre-tightened, and rotationally tensioned to achieve tensioning, prestressing control and adjustment of the FRP cloth. This tensioning method is efficient and labor-saving, does not require special mechanical equipment, and amplifies the elongation stroke of the FRP end, which can further improve the control and adjustment of the prestress of the FRP cloth. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 It is a structural schematic diagram of the FRP cloth prestressed reinforcement device of the present invention.

[0023] Figure 2 Schematic diagram of the interval impregnation and curing of FRP cloth in the FRP cloth prestressed reinforcement device and construction method thereof of the present invention.

[0024] Figure 3 Schematic diagram of the bonding and anchoring of the two ends of FRP in the FRP cloth prestressed reinforcement device and construction method of the present invention.

[0025] Figure 4 This is a structural schematic diagram of a preferred embodiment of the winding tensioning member in the FRP cloth prestressed reinforcement device of the present invention.

[0026] Figure 5 for Figure 4 Schematic diagram of the first method of wrapping FRP cloth around the tensioning member.

[0027] Figure 6 for Figure 5 Schematic diagram of the second method of wrapping FRP cloth around the tensioning member.

[0028] Figure 7 This is a schematic diagram of the installation of the extension rod in the FRP cloth prestressed reinforcement device of the present invention.

[0029] Figure 8This is a structural diagram of another preferred embodiment of the winding tensioning member in the FRP cloth prestressed reinforcement device of the present invention.

[0030] Figure 9 It is a schematic diagram of implementing prestressing and pre-tightening in the FRP cloth prestressing reinforcement device and construction method of the present invention.

[0031] Figure 10 for Figure 9 Partial top view of the positional relationship between the tensioning screw and the winding tensioning member

[0032] Figure 11 Schematic diagram of the post-tensioning process of the FRP cloth prestressed reinforcement device and its construction method according to the present invention

[0033] Figure 12 for Figure 11 A partial top view of the positional relationship between the central tensioning screw and the winding tensioning member.

[0034] Figure 13 This is a schematic diagram of applying and filling structural adhesive after tensioning is completed in the FRP cloth prestressed reinforcement device and construction method of the present invention.

[0035] Figure 14 for Figure 13 A partial top view of the positional relationship between the central tensioning screw and the winding tensioning member.

[0036] Figure 15 The figure is a curve relationship diagram between the prestress stroke magnification factor and the angle between the winding tensioning member and the surface of the structural member during tensioning in the FRP cloth prestressed reinforcement device and the construction method thereof of the present invention.

[0037] Figure 16 Schematic diagram of interval immersion curing of FRP cloth in Example 1 of the present invention.

[0038] Figure 17 Schematic diagram of the bonding and anchoring of the two ends of FRP in Example 1.

[0039] Figure 18 This is a schematic diagram of installing FRP cloth and winding tensioning members before winding in Example 1.

[0040] Figure 19 This is a schematic diagram of the FRP cloth after being wrapped around the tensioning member but before being tensioned in Example 1.

[0041] Figure 20 This is a schematic diagram of the first tensioning in Example 1.

[0042] Figure 21 This is a schematic diagram after tensioning is completed in Example 1.

[0043] Figure 22Schematic diagram of applying and filling structural adhesive in Example 1.

[0044] The corresponding relationship of the reference numbers in the accompanying drawings is as follows:

[0045] 1-FRP cloth; 21-bonding area; 22-pre-impregnation curing area; 23-post-bonding area; 3-pressing strip; 4-wrap tensioning member; 401-butt end; 402-adjustment end; 41-first through hole; 42-first internal threaded hole; 43-mounting slot; 44-opening; 51-tensioning screw; 52-fastening nut; 6-structural adhesive; α-angle between the wrap tensioning member and the surface of the structural member; α0-angle between the wrap tensioning member and the surface of the steel pipe branch; α1-angle between the wrap tensioning member and the steel pipe branch after the design pre-tension force is first reached. Angle between the tube surface; β-angle between the FRP cloth and the surface of the structural member; F-FRP tension; P-lateral tension of the tensioning screw; 7-extension rod; 71-first screw; 72-first nut; 73-avoidance groove; 8-structural member; 81-bonding anchorage area; 91-branch pipe; 92-main pipe; 101-branch pipe anchorage area; 102-main pipe bottom bonding anchorage area; 11-CFRP cloth; 12-adjusting rod; 13-second screw; 14-second internal threaded hole; 15-second nut; 16-second through hole. DETAILED DESCRIPTION

[0046] The following is a further description of specific embodiments of the present invention in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is intended to facilitate understanding of the present invention and does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0047] The technical problem to be solved by the present invention is that the existing FRP cloth is used for prestressed reinforcement, the tensioning stroke is small, ordinary tensioning tooling is difficult to apply, prestressing is difficult and easy to lose, the coordinated force performance between the fiber bundles of the FRP cloth is poor, the size effect is obvious, the strength utilization rate is low when directly bearing tension, and at the same time, the traditional anchor body is large in volume, the anchoring is cumbersome, and the cost is high. Provide an FRP cloth prestressed reinforcement device and a construction method thereof, which can achieve efficient tensioning and anchoring of the FRP cloth, without the need to drill holes or weld the original components, with easy operation and low cost. By setting a winding tensioning member, the elongation stroke of the FRP end is amplified, which can further improve the control and adjustment of the prestress of the FRP cloth, thereby improving the applicability and reinforcement effect of the prestressed FRP cloth reinforcement technology.

[0048] See also Figures 1 to 15As shown, the present invention provides an FRP cloth prestressed reinforcement device, comprising an FRP cloth 1 and a winding tensioning member 4 for winding the FRP cloth 1. Two bonding anchoring areas 81 for connecting to a structural member 8 are respectively provided at both ends of the FRP cloth 1. Preferably, a batten 3 is fixedly installed in the two bonding anchoring areas 81 at both ends of the FRP cloth 1, and the batten 3 is located on the side of the FRP cloth 1 away from the structural member 8. It should be noted that the batten 3 here can be a steel batten, and a certain length is reserved between the two bonding anchoring areas 81 when the FRP cloth 1 is bonded and anchored. Through the fixing method of bonding and anchoring, there is no need to drill holes or weld the structural members, which is convenient to operate and low in cost. It is particularly suitable for steel members that are not suitable for drilling holes, such as steel pipe structures.

[0049] Furthermore, the winding tensioning member 4 is located between the two bonding anchoring areas 81, as shown in FIG. Figures 1 to 7 As shown, by rotatably mounting the winding tension member 4 on the structural member 8, the prestress of the FRP cloth 1 can be changed when the angle of the winding tension member 4 is adjusted. Specifically, the winding tension member 4 includes an abutting end 401 that contacts the structural member 8 and is rotatably arranged on the structural member 8, and an adjusting end fixedly connected to the abutting end 401. Preferably, the adjusting end 402 is located on a side farther from the center line of the structural member 8 relative to the abutting end 402, as shown in FIG. Figures 4 to 7 As shown in FIG. 1 , a preferred embodiment of the winding tensioning member of the present invention is shown. Specifically, a mounting groove 43 for winding the FRP cloth 1 is provided on a side of the winding tensioning member 4 near the abutting end 401, and a side of the mounting groove 43 near the abutting end 401 is connected to an opening 44 for allowing the FRP cloth to pass through and be embedded in the mounting groove 43. It should be noted that there are two winding modes of the FRP cloth 1 corresponding to the position of the mounting groove 43 during winding, such as Figure 4 and Figure 5 As shown, in this embodiment, the Figure 5 In the winding method, the winding tensioning member is in the shape of a rectangular plate and is provided with an open rectangular mounting groove. The design of the opening 44 allows the FRP cloth 1 to be embedded in the mounting groove 43 from the opening 44. Therefore, the winding tensioning member 4 can be installed and replaced later, and then the FRP cloth 1 is pre-tightened by the unidirectional rotation of the winding FRP cloth 1.

[0050] See also Figure 1 、 Figures 9 to 15As shown, an adjustment component is connected to the structural member 8 so that the distance between the adjustment end 402 of the winding tensioning member 4 and the structural member 8 can be adjusted. The adjustment component includes a tensioning screw 51 installed on the structural member 8 and connected to the adjustment end 402 of the winding tensioning member 4 at one end away from the structural member 8, and a fastening nut 52 for cooperating with the tensioning screw 51 to connect the adjustment end 402 of the winding tensioning member 4 to the tensioning screw 51. Specifically, the adjustment end 402 of the winding tensioning member 4 corresponds to the tensioning screw 51 and is provided with a first through hole 41 for the tensioning screw 51 to pass through. Preferably, in this embodiment, the first through hole 41 is an oblong hole, and a moving space for the tensioning screw 51 to move along the length direction of the oblong hole is formed in the oblong hole 41, and two first through holes 41 are symmetrically provided on the winding tensioning member 4.

[0051] Furthermore, an extension rod 7 is installed on the side of the winding tensioning member 4 away from the structural member 8, and a first internal threaded hole 42 is correspondingly opened on the side of the winding tensioning member 4 relative to the installation groove 43 and on the extension rod 7. The first internal threaded hole 42 is internally threadedly connected with a first screw 71 for cooperating with the first nut 72 to connect the extension rod 7 to the winding tensioning member. Preferably, two first internal threaded holes 42 are symmetrically provided corresponding to the two first through holes 41. It should be noted that the setting of the extension rod 7 here is to tension the FRP cloth 1 by utilizing the lever principle, which can greatly reduce the tensioning force, and at the corresponding position of the tensioning screw 51, an avoidance groove 73 needs to be opened on the extension rod 7 to avoid collision. By tightening the screw 71, the distance between the winding tensioning member 4 and the extension rod 7 is adjusted, and then the winding length and tensioning state of the FRP cloth 1 are further adjusted, and finally the adjustment and control of the prestress of the FRP cloth 1 are realized.

[0052] like Figure 8As shown, it is a structural schematic diagram of another embodiment of the winding tensioning member 4 in the FRP cloth prestressed reinforcement device of the present invention, which also includes an adjusting rod 12 installed on the side of the winding tensioning member 4 away from the structural member 8. In this embodiment, the FRP cloth 1 is inserted between the adjusting rod 12 and the winding tensioning member 4 and is wound. The distance between the adjusting rod 12 and the winding tensioning member 4 is adjustable. Therefore, the width of the assembly of the adjusting rod 12 and the winding tensioning member 4 is also adjustable, thereby achieving the adjustment of the prestress. Specifically, a second through hole 16 is opened on the adjusting rod 12, and a second screw 13 is inserted into the second through hole 16. A second inner screw 13 is correspondingly opened on the winding tensioning member 4. The threaded hole 14, the second screw 13 is screwed into the second internal threaded hole 14, and is used to cooperate with the second nut 15 to connect the adjusting rod 12 to the winding tensioning member 4. It should be noted that the second through holes 16 are also symmetrically provided with two corresponding to the first through holes 41. By adjusting the position of the second screw 13 and the second nut 15, the spacing between the adjusting rod 12 and the winding tensioning member 4 is adjusted, the width of the entire assembly can be adjusted, and then the winding length and tensioning state of the FRP cloth 1 can be adjusted, and finally the adjustment and control of the prestress of the FRP cloth 1 can be realized. After the FRP cloth 1 is wrapped around the tensioning member and tightened, the lower layer of FRP cloth 1 can be pressed, providing a second anchoring defense line.

[0053] See also Figure 2 、 Figure 3 as well as Figures 9 to 15 As shown, the construction method of the FRP cloth prestressed reinforcement device for prestressed reinforcement of the present invention specifically includes the following steps:

[0054] 1) Determine the required size of the FRP sheet 1 based on the size of the structural member 8 to be reinforced and the target of prestressing, and cut the sheet into pieces;

[0055] 2) Before reinforcement, the cut and blanked FRP cloth 1 is pre-impregnated and cured in sections according to the size information of the structural component 8 to be reinforced, that is, the FRP cloth is impregnated with structural adhesive at each end distance and cured. Each pre-impregnated area is equivalent to providing an anchoring section for the fiber bundle, so as to improve the coordinated force performance of the fiber bundle when subjected to (pre) tension, thereby achieving the beneficial effect of improving the strength utilization rate of the FRP cloth. At the same time, after the interval pre-impregnation and curing, the non-pre-impregnated area of the FRP cloth can still be bent at will, retaining the lightness and shape adaptability of the FRP cloth 1. Figure 2 As shown, the FRP cloth 1 is divided into a bonding area 21, a post-bonding area 23, and a pre-impregnation curing area 22 in sequence;

[0056] 3) The surface of the structural member 8 to be reinforced is pretreated, and the two ends of the pre-impregnated and cured FRP cloth 1 are glued and anchored to the structural member 8 to be reinforced. Two bonding anchoring areas 81 are respectively provided at the two ends of the FRP cloth 1 corresponding to the structural member 8. It should be noted that when using the FRP cloth 1 for reinforcement, the two ends of the FRP cloth 1 are first glued and anchored (generally, transverse strips are also provided, which can be FRP cloth or steel strips), and a certain length of FRP cloth 1 is reserved between the two anchoring areas. The gluing and anchoring method does not require drilling or welding of the original component, and is easy to operate and low in cost. This method is particularly suitable for steel components where drilling is not suitable, such as steel pipe structures;

[0057] 4) After the bonding anchoring area 81 reaches the designed strength, the FRP sheet 1 is embedded in the mounting groove 43 on the winding tensioning member 4 and the FRP sheet 1 is rotated to pre-tighten the FRP sheet 1. Preferably, an opening 44 is provided on one side of the mounting groove 43 on the winding tensioning member 4, which is in communication with the mounting groove 43 and is used for the FRP sheet 1 to penetrate and embed into the mounting groove 43. Here, the FRP sheet 1 is prestressed by the specially designed winding tensioning member 4. The design of the opening 44 allows the FRP sheet 1 to be embedded into the mounting groove 43 through the opening 44. Therefore, the winding tensioning member 4 can be installed and replaced later, and the FRP sheet 1 can be pre-tightened by the unidirectional rotation of the winding tensioning member 4.

[0058] 5) After the FRP sheet 1 is pre-tightened, an angle-adjustable adjustment assembly is installed at one end of the winding tensioning member. The adjustment assembly includes a tensioning screw 51 and a fastening nut 52. The tensioning screw 51 is inserted into the first through hole 41 on the winding tensioning member 4, and the fastening nut 52 is tightened.

[0059] 6) By tightening the fastening nut 52, adjust the angle α between the winding tensioning member 4 and the surface of the structural member 8 so that the winding tensioning member 4 is close to the structural member 8 and prestresses the FRP sheet 1 to tighten it;

[0060] It should be noted that, unlike circular or elliptical rollers, in this embodiment, the winding tensioning member 4 is in the shape of a rectangular plate. After pre-tensioning, the surface of the winding tensioning member 4 is oblique to the surface of the reinforced structural member 1 (angle α), thereby enabling prestressing of the FRP cloth 1 through lateral tensioning. The winding tensioning member 4 is symmetrically provided with two first through holes 41 on the side away from the surface of the reinforced structural member 1. By tensioning the FRP cloth 1 laterally toward the surface of the reinforced structural member 1 through the tensioning screw 51, prestressing can be achieved. The advantages of this tensioning method are:

[0061] 1. Labor saving: According to the force balance relationship, the lateral tension P of the tensioning screw 51 is approximately equal to sin(α-β) / cosα times the tension F of the FRP cloth 1, where α is the angle between the winding tension member 4 and the surface of the structural member 8 (α<45°), and β is the angle between the FRP cloth 1 and the surface of the structural member 8 (β≤α).

[0062] P=K·F=sin(α-β) / cosα·F≤sinα / cosα·F=tanα·F

[0063] As the tensioning progresses, α and K gradually decrease, that is, the amplification factor 1 / K of the lateral tension of the tensioning screw 41 converted into the tension F of the FRP cloth 1 gradually increases. When the angle between the tensioning plate and the surface of the component tends to be parallel (that is, α approaches 0), tanα approaches 0, and the amplification factor 1 / K tends to be infinite (such as Figure 9 shown).

[0064] 2. Stroke Amplification: The tensioning stroke of the tensioning screw 51 is greater than the elongated stroke of the end of the FRP sheet 1, which is equivalent to amplifying the stroke of the FRP sheet 1. When the total length of the FRP sheet 1 is relatively short, this amplification is beneficial to controlling the tensioning force during the tensioning process and reducing the loss of prestress. The stroke amplification coefficient is related to the angle α between the winding tension member 4 and the surface of the structural member 8. Generally, the smaller the angle α, the greater the stroke amplification coefficient.

[0065] 7) After the FRP sheet 1 is tensioned and tightened, the structural adhesive 6 is applied to the gap between the FRP sheet 1 and the structural member 8 to be reinforced.

[0066] See also Figures 16 to 22 As shown, the present invention provides an embodiment for reinforcing T-shaped square tube joints. Tubular structures are a common structural form, widely used in bridges and building structures. Welded tubular joints are a common joint type for tubular structures due to their simple structure and direct force transmission path. However, due to welding defects and stress concentration, welded tubular joints have poor fatigue performance and are prone to fatigue failure under cyclic loading. To improve the fatigue performance and service life of welded tubular joints, various reinforcement methods have been proposed, such as welding steel sleeves, welding stiffening plates, and installing external stiffening rings. Although these methods can improve the fatigue performance of welded pipe nodes to a certain extent, new welds will inevitably introduce new welding defects and form new fatigue weak points, thereby affecting the reinforcement effect. In this embodiment, CFRP cloth 11 (carbon fiber cloth) is used. In this embodiment, the T-shaped square tube node includes a node main pipe 92 and a node branch pipe 91 vertically fixedly connected to the node main pipe 92. Two bonding anchoring areas are respectively provided on both sides of the node branch pipe 91, which are branch pipe anchoring areas 101 in this embodiment. The two ends of the CFRP cloth 11 along the length direction are respectively fixedly installed in the two branch pipe anchoring areas 101, and two winding tensioning members 4 are respectively provided on both sides of the node branch pipe 91 between the two branch pipe anchoring areas 101 on the CFRP cloth 11. Here, the tensioning screw 51 adopts a tensioning screw that passes through the node branch pipe 91, and the two ends of the tensioning screw are respectively connected to the two winding tensioning members.

[0067] The specific construction method for reinforcing a T-shaped square tube node according to an embodiment of the present invention includes the following steps:

[0068] Step 1: Determine the required size of the CFRP sheet 11 based on the size of the T-tube joint to be reinforced and the prestressing target, and cut it. When cutting, the stress loss during the tensioning process should be considered.

[0069] Step 2: Pre-impregnate and cure one or more layers of CFRP cloth 11 in sections and intervals according to the size information of the node to be reinforced;

[0070] Step 3: Treat the surface of the node to be reinforced: remove paint and stains from the bonding anchoring area 81, and roughen the surface of the pipe by sandblasting or wire brushing;

[0071] Step 4: Pass the pre-impregnated and cured CFRP sheet 11 from the bottom around the node main pipe 92 and adhere and anchor it to both sides of the node branch pipe 91 using a special structural adhesive 6, and set the CFRP sheet 11 circumferential bead 3;

[0072] Step 5: After the curing of the anchoring area is completed, the unimpregnated CFRP sheets 11 on both sides are respectively passed through the openings 44 into the mounting slots 43 of the two winding tensioning members 4 and wrapped 1 to 2 times to make the CFRP sheet 11 basically taut as a whole. At the same time, the winding tensioning member 4 forms an angle α0 (generally less than 45°) with the surface of the steel pipe branch 91.

[0073] Step 6: Use the tensioning screw 51 to pass through the winding tensioning members 4 on both sides, and tighten the fastening nuts 52 to apply pre-tension to the CFRP sheet 11 to meet the specified requirements. It should be noted that after the designed pre-tension is first reached, the winding tensioning member 4 and the surface of the steel pipe branch 91 still maintain a small angle α1 (<α0). After standing for 24 hours, the fastening nuts 52 can be further tightened to compensate for the prestress loss of the CFRP sheet 11.

[0074] Step 7: Apply structural adhesive 6 (structural adhesive suitable for CFRP cloth 1) to the CFRP cloth 11 and fill the gap between the CFRP cloth 11 and the winding tensioning member 4 with structural adhesive 6 (a thick paste-like structural adhesive) to provide additional protection for the CFRP cloth 11.

[0075] Step 8: Finally, apply protective coating to the fasteners and steel pipe surface.

[0076] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. It is apparent to those skilled in the art that various changes, modifications, substitutions, and variations to these embodiments may be made without departing from the principles and spirit of the present invention, and these changes and modifications still fall within the scope of protection of the present invention.

Claims

1. A FRP cloth prestressed reinforcement device, characterized in that: The invention comprises an FRP sheet and a wrapping tensioning member for wrapping the FRP sheet, wherein both ends of the FRP sheet are provided with bonding anchoring areas for connecting to structural members, and the wrapping tensioning member is located between the two bonding anchoring areas. By rotatably mounting the wrapping tensioning member on the structural member, the prestress applied to the FRP sheet can be changed when the angle of the wrapping tensioning member is adjusted; The winding tensioning member includes an abutting end that contacts the structural member and is rotatably arranged on the structural member, and an adjusting end fixedly connected to the abutting end. The adjusting end is located on the side farther away from the center line of the structural member relative to the abutting end, and an adjusting component is connected to the structural member so that the distance between the adjusting end and the structural member can be adjusted.

2. The FRP cloth prestressed reinforcement device according to claim 1, characterized in that: A mounting groove for winding the FRP cloth is provided on one side of the winding and tensioning member close to the abutting end, and an opening for allowing the FRP cloth to pass through and be embedded in the mounting groove is connected to the mounting groove on one side close to the abutting end.

3. The FRP cloth prestressed reinforcement device according to claim 2, characterized in that: An extension rod is installed on the side of the winding and tensioning member away from the structural member. A first internal threaded hole is correspondingly opened on the side of the winding and tensioning member opposite to the installation groove and on the extension rod. The first internal threaded hole is screwed with a first screw for cooperating with a first nut to connect the extension rod to the winding and tensioning member.

4. The FRP cloth prestressed reinforcement device according to claim 1, characterized in that: It also includes an adjusting rod installed on the side of the winding and tensioning member away from the structural member, a second screw is installed on the adjusting rod, and a second internal threaded hole is correspondingly opened on the winding and tensioning member. The second screw is screwed into the second internal threaded hole and is used to cooperate with a second nut to connect the adjusting rod and the winding and tensioning member.

5. The FRP cloth prestressed reinforcement device according to claim 4, characterized in that: The FRP cloth passes through and is wound between the winding and tensioning member and the adjusting rod.

6. The FRP cloth prestressed reinforcement device according to any one of claims 2 or 4, characterized in that: The adjustment assembly includes a tensioning screw installed on the structural member and connected to the adjustment end at one end away from the structural member, a fastening nut for cooperating with the tensioning screw to connect the adjustment end to the tensioning screw, and the adjustment end is provided with a first through hole for the tensioning screw to pass through.

7. The FRP cloth prestressed reinforcement device according to claim 6, characterized in that: The first through hole is an oblong hole, and a moving space is formed in the oblong hole for the tensioning screw to move along the length direction of the oblong hole.

8. The FRP cloth prestressed reinforcement device according to claim 1, characterized in that: Two ends of the FRP cloth are respectively connected to two sides of the structural member, and two winding tensioning members are respectively wound around the FRP cloth corresponding to two sides of the structural member.

9. A construction method for prestressed reinforcement using the FRP cloth prestressed reinforcement device as claimed in any one of claims 1 to 8, characterized in that: The steps include: The bonding anchoring areas at both ends of the FRP cloth are glued and anchored on the structural member to be reinforced, and a certain length of FRP cloth is reserved between the two bonding anchoring areas; Installing a winding tensioning member on the structural member to be reinforced, wrapping the FRP sheet through the winding tensioning member, and pre-tightening the FRP sheet; Installing an adjustment assembly on the winding tensioning member; The angle between the winding tensioning member and the structural member to be reinforced is adjusted by adjusting the assembly so that the winding tensioning member fits close to the structural member to be reinforced, and prestressed tensioning is applied to the FRP cloth.

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