A filling type longitudinal tensioned CFRP plate anchoring system and its construction method

Abstract

This invention discloses a plug-type longitudinally tensioned CFRP plate anchorage system and its construction method, belonging to the field of external prestressing reinforcement technology in civil engineering. It includes a structural member to be reinforced and a CFRP plate. Both ends of the CFRP plate are connected to the structural member through anchoring devices. At least one of the anchoring devices is a plug-type longitudinally tensioned anchorage device. At least one support device is also provided between the CFRP plate and the structural member to be reinforced. The CFRP plate is located away from the neutral axis of the structural member to enhance the prestressing effect, thereby specifically solving the technical problem of mid-span deflection of the structural member to be reinforced. In the plug-type longitudinally tensioned anchorage device, prestress loss can be avoided by inserting pins into the strip holes and pin holes, and by filling the redundant space of the strip holes with plugs, making construction more convenient. At the same time, the tensioning frame, sliding seat, and pre-tensioning frame can be easily disassembled after inserting the pins and filling the plugs, reducing construction costs.

Description

Technical Field

[0001] This invention relates to the technical field of applying external prestressing reinforcement in civil engineering, and more specifically, to a crammed longitudinal tensioned CFRP plate anchoring system and its construction method. Background Technology

[0002] In modern buildings, transportation, bridges and other engineering structures, concrete or steel structural components may experience changes in load due to environmental erosion, material aging, and altered structural functions, or may suffer from insufficient load-bearing capacity or cracking due to natural disasters, posing significant safety hazards.

[0003] Currently, reinforcement methods for engineering components are broadly classified into two categories based on their working principles: passive reinforcement and active reinforcement. Passive reinforcement involves directly adding tensile (or shear) reinforcing materials to the weak areas of a component under tension (or shear), such as bonding steel plates or high-strength fiber composites (carbon fiber, aramid fiber). The reinforcing materials only bear the internal forces caused by live loads and subsequent dead loads; compared to the original load-bearing component, their strain (stress) is relatively delayed. Especially with the direct bonding of high-strength fiber composites, the high tensile strength of the reinforcing materials is difficult to utilize effectively. Therefore, passive reinforcement cannot reduce the deformation of the original structure or close cracks. Active reinforcement, on the other hand, involves applying prestress to the reinforcing materials placed in the weak areas of a component under tension (or shear). The reinforcing materials actively bear the load, fundamentally solving the problem of strain (stress) lag in the added reinforcing materials. This allows the high tensile strength of the reinforcing materials to be fully utilized, improving material utilization efficiency. The flexural bearing capacity and normal working performance of the reinforced component are significantly improved.

[0004] Active reinforcement methods inevitably utilize a supporting tensioning system. For example, Chinese invention patent ZL202010702249.2 discloses a tensioning and anchoring device for reinforcing beams with prestressed CFRP plates and its usage method. The device includes a CFRP plate, an anchoring assembly, and a tensioning assembly. The tensioning assembly includes a tensioning slide, a second clamp, a limiting plate, and a tensioning mechanism. The contact surfaces of the telescopic plate and the second clamp are provided with serrations facing opposite directions. This patent applies prestress by installing two sets of clamps fixed at both ends of the CFRP plate within two sets of slides, preventing eccentric tension. Furthermore, the serrations between the telescopic plate and the second clamp work together to achieve self-locking of the CFRP plate after prestressing is applied, limiting the retraction of the CFRP plate.

[0005] However, the above-mentioned patents have the following drawbacks in engineering applications:

[0006] (1) After the tensioning mechanism is removed, the CFRP plate rebounds, and there is redundant space between the saw teeth, which reduces the prestress of the CFRP plate and fails to meet the preset standard.

[0007] (2) During the tensioning process, the CFRP plate is always attached to the outer surface of the structure to be reinforced (i.e., surface prestress is applied), which results in the CFRP plate being close to the neutral axis of the structure to be reinforced, and the reinforcement effect is poor.

[0008] (3) When arranging reinforcement materials with a larger eccentricity, due to the poor shear resistance of CFRP plates, carbon fiber reinforced composite materials are prone to brittle fracture when subjected to external forces perpendicular to the plane of CFRP plates, resulting in very limited negative bending moments that can be provided to the structural members to be reinforced. Therefore, it cannot effectively solve the technical problem of mid-span deflection of the structural members to be reinforced. Summary of the Invention

[0009] To address the shortcomings of existing technologies, this invention provides a plug-type longitudinally tensioned CFRP plate anchoring system and its construction method. The plug-type longitudinally tensioned anchoring device is tensioned and installed using a tensioning frame. It is fixed by inserting plugs and pins through pin holes and strip holes. The redundant space is filled with plugs, which avoids prestress loss and solves the technical problems in the background art.

[0010] To achieve the above objectives, the present invention provides the following technical solution: a crammed, longitudinally tensioned CFRP plate anchoring system and its construction method, comprising a structural member to be reinforced and a CFRP plate. The key feature is that both ends of the CFRP plate are connected to the structural member to be reinforced via anchoring devices, at least one of the two anchoring devices is a crammed, longitudinally tensioned anchoring device, and at least one support device is also provided between the CFRP plate and the structural member to be reinforced. The crammed, longitudinally tensioned anchoring device includes an anchor seat and a CFRP anchor. The anchor is fixedly installed on the structural member to be reinforced. A rotating shaft passes through the anchor and a steering block is hinged to the anchor via the rotating shaft. A pin hole is opened at the end of the steering block away from the rotating shaft. One end of the CFRP anchor is connected to the CFRP plate, and the other end is provided with a clamping plate assembly. A strip hole is opened on the clamping plate assembly in the tensioning direction. The plug-type forward tensioning anchoring device is tensioned and installed through a detachable tensioning frame. After tensioning, the steering block and the clamping plate assembly are connected through the pin hole and the strip hole by inserting a pin and a plug.

[0011] As a preferred embodiment of the present invention, a connecting block is provided between the steering block and the clamping plate assembly, the pin hole is provided on the connecting block, and the end of the connecting block away from the clamping plate assembly is rotatably connected to the steering block by a rotating pin, and the rotating shaft is orthogonal to the central axis of the rotating pin.

[0012] As a preferred technical solution of the present invention, the tensioning frame includes a first installation beam and a second installation beam. The first installation beam is clamped on the connecting block. A traction screw rod is slidably penetrated through the first installation beam and the second installation beam to form an "open" shape. Nuts are provided at both ends of the traction screw rod for limiting. A hollow jack is sleeved on the traction screw rod, and both ends of the hollow jack respectively abut against the nut and the side of the second installation beam away from the first installation beam.

[0013] As a preferred technical solution of the present invention, the tensioning frame includes two mutually parallel traction screw rods. One ends of the two traction screw rods on the same side are provided with collar rings. The two collar rings are respectively rotatably sleeved on both ends of the rotating shaft. The ends of the two traction screw rods away from the collar rings are both slidably penetrated through the second installation beam to form a "艹" shape, and nuts are provided at the ends. A hollow jack is sleeved on the traction screw rod, and both ends of the hollow jack respectively abut against the nut and the side of the second installation beam away from the collar ring.

[0014] As a preferred technical solution of the present invention, the CFRP anchor is abutted against the side of the second installation beam away from the hollow jack.

[0015] As a preferred technical solution of the present invention, the second installation beam is provided with a channel opening for the CFRP plate to penetrate through.

[0016] As a preferred technical solution of the present invention, the CFRP anchor is hung on the side of the second installation beam facing the hollow jack.

[0017] As a preferred technical solution of the present invention, the CFRP anchor is one of a flat anchor, a wedge anchor or a corrugated anchor.

[0018] As a preferred technical solution of the present invention, multiple layers of CFRP plate anchor interfaces are provided in the CFRP anchor.

[0019] Based on the structure described above, the present invention also provides a construction method for a stuffing type forward tensioning CFRP plate anchoring system. The key lies in the following steps:

[0020] S1: Install the stuffing type forward tensioning anchoring device on the tensioning frame;

[0021] S2: Fix both ends of the CFRP plate on the structure to be strengthened, and at least one end of the CFRP plate is fixed by using the stuffing type forward tensioning anchoring device;

[0022] S3: Set up a support device between the CFRP plate and the structure to be strengthened at a predetermined spacing;

[0023] S4: Drive the CFRP anchor through the tensioning frame to tension the CFRP plate;

[0024] S5: After the target prestress is reached, the plug-type forward tensioning anchoring device is fixed by inserting pins through the pin holes and strip holes and filling the redundant space of the strip holes with plugs.

[0025] S6: Remove the tensioning frame.

[0026] This invention provides a bridging type longitudinal tensioned CFRP plate anchoring system and its construction method, which has the following beneficial effects:

[0027] 1. This invention can arrange reinforcement materials with a larger eccentricity. On the one hand, it can move the CFRP plate away from the neutral axis of the structure to be reinforced, thereby improving the effect of prestressing and thus specifically solving the technical problem of mid-span deflection of the structure to be reinforced. On the other hand, after the CFRP plate is brought to the target prestress by the tensioning and filling type forward tensioning and anchoring device, the prestress loss can be avoided by inserting pins into the strip holes and pin holes and filling the redundant space of the strip holes with plugs, making construction more convenient. At the same time, the tensioning frame, sliding seat, and prestressing frame can be easily disassembled after inserting pins and filling plugs, reducing construction costs.

[0028] 2. During the process of applying prestress to the CFRP plate by the pretensioning frame, the CFRP anchor can adaptively adjust its included angle with the reinforced structural member under the action of the rotating shaft, so as to effectively deal with the stress concentration caused by the change of cross section and material stiffness between the CFRP plate and the CFRP anchor, eliminate the external force perpendicular to the plane of the CFRP plate, and thus prevent the CFRP plate from brittle fracture while efficiently applying prestress.

[0029] 3. No CFRP reinforcement is required throughout the process, making construction more convenient and cost-effective;

[0030] 4. CFRP anchors can be freely replaced according to the actual situation of the structural parts to be processed, the reinforcement form of the CFRP plate, and the amount of prestress applied, thereby significantly improving the versatility of the end fixing system and making its application range wider.

[0031] 5. It has broad application prospects. It can be used not only for external prestressing reinforcement, but also for new structures, such as steel structures, concrete structures, wood structures, composite structures, etc. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of the crammed convex tensioned CFRP plate anchorage system provided in this embodiment;

[0033] Figure 2 This is a schematic diagram of the structure of the bridging type longitudinal tensioned CFRP plate anchoring device provided in this embodiment;

[0034] Figure 3 This is a bottom view of the structure of the crammed convex tensioned CFRP plate anchoring device provided in this embodiment;

[0035] Figure 4 This is a schematic diagram of the completed state of the crammed convex tensioned CFRP plate anchorage system provided in this embodiment;

[0036] Figure 5 Provided for this embodiment Figure 4 Enlarged structural diagram of section A in the middle;

[0037] Figure 6 This is a schematic diagram of the structure of the CFRP plate anchoring device with a collar structure provided in this embodiment.

[0038] Figure 7 A bottom view of the CFRP plate anchoring device with a collar structure provided in this embodiment;

[0039] Figure 8 This is a schematic diagram of the completed state of the CFRP plate anchoring system with a collar structure provided in this embodiment.

[0040] Figure 9 Provided for this embodiment Figure 8 Enlarged structural diagram of section B in the middle.

[0041] In the diagram: 1. Structural component to be reinforced; 2. CFRP plate; 3. Support device; 4. Filler-type forward tensioning anchoring device; 41. Anchor seat; 42. Rotating shaft; 43. Steering block; 44. Pin hole; 45. Strip hole; 46. Pin; 47. Plug; 48. Clamping plate assembly; 49. CFRP anchor; 400. Connecting block; 401. Rotating pin; 5. Tensioning frame; 51. First mounting beam; 52. Traction screw; 53. Second mounting beam; 54. Hollow jack; 55. Collar; 56. Channel opening. Detailed Implementation

[0042] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0043] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0044] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0045] This invention provides the following technical solutions:

[0046] Example 1: As Figure 1 As shown, a crammed, longitudinally tensioned CFRP plate anchoring system includes a structural member 1 to be reinforced and a CFRP plate 2. The key feature is that both ends of the CFRP plate 2 are connected to the structural member 1 to be reinforced via anchoring devices. At least one of the anchoring devices is a crammed, longitudinally tensioned anchoring device 4. At least one support device 3 is also provided between the CFRP plate 2 and the structural member 1 to be reinforced, such as... Figure 2 Figure 3 As shown, the cramming type forward tensioning anchoring device 4 includes an anchor seat 41 and a CFRP anchor 49. The anchor seat 41 is fixedly installed on the structural member 1 to be reinforced. A rotating shaft 42 passes through the anchor seat 41, and a steering block 43 is hinged to the anchor seat 41 via the rotating shaft 42. The CFRP anchor 49 can adaptively adjust its included angle with the structural member 1 to be reinforced under the action of the rotating shaft 42, so as to effectively cope with the stress concentration caused by the cross-sectional change and material stiffness change between the CFRP plate 2 and the CFRP anchor 49, and eliminate the stress perpendicular to the CFRP plate 2. External forces are applied to the surface, thereby preventing brittle fracture of the CFRP plate 2 while efficiently applying prestress. A pin hole 44 is provided at the end of the steering block 43 away from the rotating shaft 42. One end of the CFRP anchor 49 is connected to the CFRP plate 2, and the other end is equipped with a clamping plate assembly 48. A strip-shaped hole 45 is provided on the clamping plate assembly 48 in the tensioning direction. The plug-type forward tensioning anchoring device 4 is tensioned and installed via a detachable tensioning frame 5. The tensioning frame 5 drives the CFRP anchor 49 to move, using the CFRP plate 2 for tensioning to achieve external prestressing of the structural member 1 to be reinforced. Figure 4 Figure 5 As shown, after tensioning, a pin 46 is inserted through the pin hole 44 and the strip hole 45, and a plug 47 is filled in the redundant space of the strip hole 45 to connect the steering block 43 and the clamping plate assembly 48. The plug 47 filling the redundant space of the strip hole 45 prevents the CFRP plate 2 from rebounding and reducing the external prestress after the tensioning frame 5 is removed. At the same time, the amount of external prestress can be adjusted by adjusting the number of plugs 47.

[0047] like Figure 2 Figure 3 As shown, a connecting block 400 is provided between the steering block 43 and the clamping plate assembly 48. A pin hole 44 is provided on the connecting block 400. The end of the connecting block 400 away from the clamping plate assembly 48 is rotatably connected to the steering block 43 by inserting a rotating pin 401. The rotating shaft 42 is orthogonal to the central axis of the rotating pin 401. By rotating the connecting block 400 and the steering block 43 relative to each other, the left and right angle of the CFRP plate 2 can be adaptively adjusted, which can further achieve efficient application of prestress while preventing the CFRP plate 2 from brittle fracture.

[0048] Among them, such as Figure 2 Figure 3 As shown, the tensioning frame 5 includes a first mounting beam 51 and a second mounting beam 53. The tensioning frame 5 includes two halves, the first mounting beam 51 and the second mounting beam 53, which are spliced ​​together in a detachable manner. The purpose is to facilitate the disassembly and assembly of the first mounting beam 51 and the second mounting beam 53 when the tensioning frame 5 is disassembled and assembled. The first mounting beam 51 is engaged with the connecting block 400. The traction screw 52 slides through the first mounting beam 51 and the second mounting beam 53 to form an "open" shape. Nuts are provided at both ends of the traction screw 52 for limiting. A hollow jack 54 is sleeved on the traction screw 52. The two ends of the hollow jack 54 abut against the nut and the side of the second mounting beam 53 away from the first mounting beam 51, respectively.

[0049] Among them, such as Figure 2 Figure 3 As shown, the CFRP anchor 49 abuts against the side of the second mounting beam 53 away from the hollow jack 54. Through the extension of the hollow jack 54, the second mounting beam 53 is pushed along the direction of the traction screw 52, ​​causing the second mounting beam 53 to move the CFRP anchor 49, thereby achieving the tensioning effect of the CFRP anchor 49 on the CFRP plate 2. The second mounting beam 53 has a reserved channel opening 56 for the CFRP plate 2 to pass through. The CFRP anchor 49 is one of a flat anchor, a wedge anchor, or a corrugated anchor. The anchoring form can be one or more of the following: adhesive anchoring, wedge anchoring, or friction anchoring. Preferably, in order to meet the construction requirements of structures with different tonnages, the CFRP anchor 49 can be provided with a single-layer CFRP plate 2 anchor interface or a multi-layer CFRP plate 2 anchor interface.

[0050] Example 2: As Figure 6 Figure 7 shown, adjustments are made to the structure of Example 1. The connection block 400 and the insertion rotating pin 401 are cancelled, and the tensioning frame 5 is also adjusted accordingly. The tensioning frame 5 includes two parallel traction screws 52. One end of the two traction screws 52 on the same side is provided with collars 55, and the two collars 55 are respectively rotatably sleeved at both ends of the rotating shaft 42. The ends of the two traction screws 52 far from the collars 55 both slide through the second installation beam 53 to form a "艹" shape, and nuts are provided at the ends. A hollow jack 54 is sleeved on the traction screw 52, and both ends of the hollow jack 54 respectively abut against the nut and the side of the second installation beam 53 far from the collar 55. As Figure 8 Figure 9 shown, after the tensioning is completed, the tensioning frame 5 is also removed.

[0051] Example 3: In Example 1 or Example 2, the installation position of the CFRP anchor 49 is adjusted, and the CFRP anchor 49 is changed to be hung on the side of the second installation beam 53 facing the hollow jack 54 (not shown in the figure). At this time, the channel opening 56 reserved on the second installation beam 53 for the CFRP plate 2 to pass through can be cancelled. It should be noted that at this time, the second installation beam 53 passes through the splint assembly 48.

[0052] Based on the stuffing type forward tensioning CFRP plate anchoring system described above, this embodiment also discloses a construction method for the stuffing type forward tensioning CFRP plate anchoring system, including the following steps:

[0053] S1: Install the stuffing type forward tensioning anchoring device 4 on the tensioning frame 5;

[0054] S2: Fix both ends of the CFRP plate 2 on the to-be-strengthened structural member 1, and at least one end of the CFRP plate 2 is fixed by the stuffing type forward tensioning anchoring device 4;

[0055] S3: Set the support device 3 between the CFRP plate 2 and the to-be-strengthened structural member 1 at a predetermined spacing. The support device 3 can be set to one according to the length of the strengthened structural member 1, or multiple can be set at intervals;

[0056] S4: Drive the CFRP anchor 49 through the tensioning frame 5 to tension the CFRP plate 2. When tensioning, make the strip holes 45 on the splint assembly 48 overlap with the pin holes 44;

[0057] S5: After reaching the target prestress, fix the stuffing type forward tensioning anchoring device 4 by inserting pins 46 through the pin holes 44 and the strip holes 45, and filling the redundant space of the strip holes 45 with the plug pieces 47, which can also avoid prestress loss;

[0058] S6: Remove tensioning frame 5, which can be reused, reducing construction costs.

[0059] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A bridging type longitudinal tensioned CFRP plate anchoring system, comprising a structural member to be reinforced (1) and a CFRP plate (2), characterized in that: The two ends of the CFRP plate (2) are respectively connected to the structural member (1) to be reinforced by anchoring devices. At least one of the two anchoring devices is a plug-type forward tension anchoring device (4). At least one support device (3) is also provided between the CFRP plate (2) and the structural member (1) to be reinforced. The plug-type forward tension anchoring device (4) includes an anchor seat (41) and a CFRP anchor (49). The anchor seat (41) is fixedly installed on the structural member (1) to be reinforced. A rotating shaft (42) passes through the anchor seat (41), and a device is hinged to the anchor seat (41) through the rotating shaft (42). The CFRP anchor (49) is connected to the CFRP plate (2) at one end and has a pin hole (44) at the other end. The CFRP anchor (49) is connected to the CFRP plate (2) at one end and has a clamping plate assembly (48) at the other end. The clamping plate assembly (48) has a strip hole (45) in the tensioning direction. The plugging type forward tensioning anchoring device (4) is tensioned and installed through a detachable tensioning frame (5). After tensioning, the CFRP anchor (49) and the clamping plate assembly (48) are connected through the pin hole (44) and the strip hole (45) with a pin (46) and a plug (47). A connecting block (400) is provided between the steering block (43) and the clamping plate assembly (48). The pin hole (44) is provided on the connecting block (400). The end of the connecting block (400) away from the clamping plate assembly (48) is connected to the steering block (43) by inserting a rotating pin (401). The rotating shaft (42) is orthogonal to the central axis of the rotating pin (401). The tensioning frame (5) includes a first mounting beam (51) and a second mounting beam (53). The first mounting beam (51) is engaged with the connecting block (400). A traction screw (52) is slidably passed through the first mounting beam (51) and the second mounting beam (53) to form an "open" shape. Nuts are provided at both ends of the traction screw (52) for limiting. A hollow jack (54) is sleeved on the traction screw (52). The two ends of the hollow jack (54) respectively abut against the nut and the side of the second mounting beam (53) away from the first mounting beam (51).

2. The bridging type longitudinal tensioned CFRP plate anchoring system according to claim 1, characterized in that: The CFRP anchor (49) abuts against the side of the second mounting beam (53) away from the hollow jack (54).

3. The bridging type longitudinal tensioned CFRP plate anchoring system according to claim 2, characterized in that: The second mounting beam (53) has a channel (56) for the CFRP plate (2) to pass through.

4. The bridging type longitudinal tensioned CFRP plate anchoring system according to claim 1, characterized in that: The CFRP anchor (49) is attached to the side of the second mounting beam (53) facing the hollow jack (54).

5. The bridging type longitudinal tensioned CFRP plate anchoring system according to any one of claims 1-4, characterized in that: The CFRP anchor (49) is one of a flat anchor, a wedge anchor, or a wave anchor.

6. The bridging type longitudinally tensioned CFRP plate anchoring system according to any one of claims 1-4, characterized in that: The CFRP anchor (49) is provided with a multi-layer CFRP plate anchor interface.

7. The construction method of the bridging type longitudinal tensioned CFRP plate anchoring system as described in any one of claims 1-6, characterized in that, Includes the following steps: S1: Install the bridging type forward tensioning anchoring device (4) on the tensioning frame (5); S2: Fix both ends of the CFRP plate (2) to the structural member (1) to be reinforced, wherein at least one end of the CFRP plate (2) is fixed by a plug-type forward tensioning anchoring device (4); S3: Install support devices (3) between the CFRP plate (2) and the structural member (1) to be reinforced at predetermined intervals. S4: The CFRP plate (2) is tensioned by the tensioning frame (5) driving the CFRP anchor (49); S5: After the target prestress is reached, the plug-type forward tensioning anchoring device (4) is fixed by inserting a pin (46) through the pin hole (44) and the strip hole (45) and filling the redundant space of the strip hole (45) with a plug (47); S6: Remove the tensioning frame (5).

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