UHPC-FRP material composite reinforcing belt for improving performance of existing structure

Abstract

The invention discloses a UHPC-FRP (Ultra High Performance Concrete-Fiber Reinforce Plastic) material composite reinforcing belt for improving the performance of an existing structure, which belongs to the technical field of building construction and comprises two symmetrically arranged supporting structures connected with the existing building, a grid layer bonded with the existing building is arranged between the adjacent supporting structures, the grid layer is made of an FRP material, and the FRP material is arranged between the adjacent supporting structures. A winding structure for winding the corresponding end part of the grid layer is arranged in each supporting structure; the supporting structure is characterized by further comprising a supporting formwork made of UHPC, the supporting formwork comprises an annular side plate and an end plate used for sealing the side plate, the upper end of the inner wall of the side plate is connected with the top end of the supporting structure, the end plate and the side plate are bonded, and a grouting groove used for pouring UHPC concrete is formed in the top end of the side plate; the FRP grid reinforcing method aims at solving the problems that in an existing FRP grid reinforcing method, an FRP grid is not easy to install, and the connection strength is not easy to guarantee when the installed FRP grid is bonded with a post-pouring material.

Description

Technical Field

[0001] This invention belongs to the field of building construction technology, specifically relating to a UHPC-FRP composite reinforcement strip for improving the performance of existing structures. Background Technology

[0002] Due to factors such as disaster damage, early construction date, and corrosion from the environment, existing building structures may fail to meet the requirements of current codes in terms of component load-bearing capacity and seismic performance. Therefore, it is necessary to repair, reinforce, or renovate the structure to ensure that the structural reliability meets the requirements.

[0003] Currently, reinforcement methods using FRP mesh often require pre-applying an epoxy resin coating to the FRP mesh before pouring high-strength composite mortar or UHPC. However, in actual reinforcement processes, this construction process faces challenges such as the difficulty in installing FRP mesh and the difficulty in ensuring the bonding strength between the installed FRP mesh and the subsequently poured material. Summary of the Invention

[0004] In view of this, the present invention discloses a UHPC-FRP composite reinforcement strip for improving the performance of existing structures. Its purpose is to solve the problems in existing FRP mesh reinforcement methods, such as the difficulty in installing FRP mesh and the difficulty in ensuring the bonding strength between the installed FRP mesh and the post-cast material.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A UHPC-FRP composite reinforcement strip for improving the performance of existing structures includes two symmetrically arranged support structures connected to the existing building. A mesh layer bonded to the existing building is provided between adjacent support structures. The mesh layer is made of FRP material. Each support structure has a winding structure for winding up the corresponding ends of the mesh layer. The strip also includes a UHPC material support template, which includes annular side plates and end plates for closing the side plates. The upper end of the inner wall of the side plate is connected to the top of the support structure. The end plate is bonded to the side plate. A grouting groove for pouring UHPC concrete is provided at the top of the side plate.

[0007] In this scheme, the supporting structure, grid layer, and side panels are installed on the existing building, with a self-adhesive epoxy layer applied between the grid layer and the existing building. A winding structure is then used to tension and wind up both ends of the grid layer, ensuring that the grid layer unfolds while also adhering tightly to the existing building. After bonding the ends to the side panels, UHPC concrete is injected into the supporting formwork through grouting grooves, thus completing the reinforcement strip construction. This scheme, through the setting of the supporting formwork, ensures full contact between the post-cast UHPC concrete and the grid layer and the existing building, thereby guaranteeing the connection strength between the grid layer and the post-cast UHPC concrete. Furthermore, the winding structure at both ends provides a certain amount of prestress to the grid layer, allowing it to bear force in the reinforcement strip in advance, generating a certain amount of pre-compression stress within the reinforcement strip. This pre-compression stress can counteract the tensile stress caused by external loads, effectively delaying or reducing the occurrence of cracks in the reinforcement strip and improving the crack resistance of the structure.

[0008] Furthermore, the support structure includes an annular support shell, with slots for the mesh layer to enter and exit on the opposing end faces of adjacent support shells, and a cover plate facing the slot is hinged to the side of the support shell away from the existing building; the winding structure includes a winding drum coaxially rotatably connected to the bottom of the support shell, with several positioning protrusions fixed around the circumference of the winding drum, each protruding through the mesh of the mesh layer, and a clamping block detachably connected to the positioning protrusion; a rotating shaft with its top end penetrating the support shell and extending upwards out of the side plate is coaxially slidably connected inside the winding drum, and a locking structure is provided between the rotating shaft and the side plate.

[0009] During construction, the support shell is installed on the existing building using bolts or other methods. The cover plate is then opened, and the end of the grid layer is wound around the winding drum through the slot, ensuring that the positioning protrusions pass through the mesh of the grid layer. A clamping plate is then fixed to the positioning protrusions to press and secure the grid layer onto the winding drum. The cover plate is then fastened to the slot. After contact with the locking structure, the winding drum is wound up by rotating the shaft. Once the grid layer is wound in place, the shaft is locked using the locking structure, thus restricting the grid layer. In this scheme, the shaft allows for adjustment of the prestress of the grid layer during and after the UHPC concrete has solidified, based on the construction conditions. This ensures that the crack resistance of the reinforced strip after molding better meets the reinforcement requirements of the existing building.

[0010] Furthermore, the supporting template also includes a steel mesh installed on the inner wall of the side plate. Several pull-out bases are provided on the steel mesh. Each pull-out base has a spherical cavity at its end facing the existing building. A connecting ball is movably installed within each spherical cavity. An adjusting rod facing the existing building is fixed to each connecting ball. A rotating sleeve is coaxially threaded to the end of each adjusting rod. A pull-out rod is coaxially rotatably connected to the end of each rotating sleeve. Several support rods inclined towards the connecting ball are hinged to the periphery of the end of each pull-out rod, and a supporting elastic element is provided between the support rods and the pull-out rods. Several stops limiting the deflection angle of the support rods are provided on the periphery of the end of each pull-out rod. The connecting member includes several supports embedded in the end plate. Bolts are provided between the supports and adjacent end faces of the pull-out bases. Several stepped holes corresponding to the pull-out rods are opened on the existing building. The outer diameter of each stepped hole is smaller than its inner diameter.

[0011] After the mesh layer is initially tensioned, the connecting ball is deflected and the adjusting rod is rotated, so that the rotating sleeve and anti-pull rod at the end of the adjusting rod are inserted into the corresponding stepped hole. At this time, the support rod contacts the stepped end face of the stepped hole under the action of the supporting elastic element. Then, the adjusting rod is rotated in the opposite direction, and the adjusting rod drives the rotating sleeve and anti-pull rod to move in the direction of the rotating sleeve and anti-pull rod. The support rod is then pushed open by the end face of the stepped hole. Then, the end plate and the side plate are bonded together, and bolts are installed between the support and the corresponding anti-pull seat to strengthen the connection strength between the side plate, the end plate and the existing building, thereby strengthening the connection strength between the reinforcement strip and the existing building and preventing the reinforcement strip from falling off.

[0012] Furthermore, a rubber roller parallel to the end of the cover plate is rotatably connected to it.

[0013] Furthermore, it also includes repair microcapsules mixed inside the UHPC concrete, the repair microcapsules having an epoxy resin core material.

[0014] Furthermore, a self-adhesive epoxy layer is provided on both sides of the side plate.

[0015] Furthermore, the locking structure includes several limiting protrusions fixed to the end of the rotating shaft, and each side plate is provided with a limiting groove that cooperates with the limiting protrusions.

[0016] Other advantages, objectives, and features of the invention will be set forth in the following description and will be apparent to those skilled in the art in some respects, or may be learned by practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0017] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the following figures are provided for illustration:

[0018] Figure 1 This is a schematic diagram of the structure of an embodiment of the present invention;

[0019] Figure 2 This is a longitudinal sectional view of an embodiment of the present invention;

[0020] Figure 3 for Figure 2 Enlarged view of point A in the middle;

[0021] Figure 4 This is a schematic diagram of the support structure in an embodiment of the present invention.

[0022] The following are labeled in the attached diagram: 1. Grid layer; 2. Side plate; 3. End plate; 4. Grouting groove; 5. Support shell; 6. Groove; 7. Rewinding drum; 8. Rotating shaft; 9. Positioning protrusion; 10. Pressing block; 11. Cover plate; 12. Reinforcing mesh; 13. Pull-out base; 14. Connecting ball; 15. Adjusting rod; 16. Rotating sleeve; 17. Pull-out rod; 18. Support elastic element; 19. Support rod; 20. Stop block; 21. Step hole; 22. Rubber roller; 23. Limiting protrusion; 24. Existing building; 25. Support. Detailed Implementation

[0023] like Figures 1-4 As shown:

[0024] A UHPC-FRP composite reinforcement strip for reinforcing existing buildings 24 includes two symmetrically arranged support structures connected to the existing buildings 24. A mesh layer 1, which is bonded to the existing buildings 24, is provided between adjacent support structures. The mesh layer 1 is made of FRP material. Each support structure has a winding structure for winding up the corresponding ends of the mesh layer 1. The strip also includes a UHPC material support template, which includes an annular side plate 2 and an end plate 3 for closing the side plate 2. The upper end of the inner wall of the side plate 2 is connected to the top of the support structure. The end plate 3 is bonded to the side plate 2. A grouting groove for pouring UHPC concrete is provided at the top of the side plate 2.

[0025] In this scheme, the supporting structure, grid layer 1, and side plate 2 are installed on the existing building 24, and a self-adhesive epoxy layer is applied between the grid layer 1 and the existing building 24. Then, the two ends of the grid layer 1 are tensioned and wound up using a winding structure to ensure that the grid layer 1 unfolds while also tightly adhering to the existing building 24. After the ends are bonded to the side plate 2, UHPC concrete is injected into the supporting formwork through grouting grooves, thus completing the construction of the reinforcement strip. In this scheme, the setting of the supporting formwork ensures full contact between the post-cast UHPC concrete and the grid layer 1 and the existing building 24, thereby ensuring the connection strength between the grid layer 1 and the post-cast UHPC concrete. Furthermore, the winding structure at both ends provides a certain amount of prestress to the grid layer 1, allowing it to be stressed in advance within the reinforcement strip, generating a certain amount of pre-compression stress within the reinforcement strip. This pre-compression stress can counteract the tensile stress caused by external loads, effectively delaying or reducing the occurrence of cracks in the reinforcement strip and improving the crack resistance of the structure.

[0026] In this embodiment, the support structure includes an annular support shell 5. The opposing end faces of adjacent support shells 5 are provided with slots 6 for the mesh layer 1 to enter and exit. The side of the support shell 5 away from the existing building 24 is hinged with a cover plate 11 facing the slot 6. The winding structure includes a winding drum 7 coaxially rotatably connected to the bottom of the support shell 5. Several positioning protrusions 9 passing through the mesh of the mesh layer 1 are fixed around the winding drum 7. A clamping block 10 is detachably connected to the positioning protrusion 9. A rotating shaft 8 with its top end penetrating the support shell 5 and extending upward to the side plate 2 is coaxially slidably connected inside the winding drum 7. A locking structure is provided between the rotating shaft 8 and the side plate 2.

[0027] During construction, the support shell 5 is installed on the existing building 24 using bolts or other means. The cover plate 11 is opened, and the end of the mesh layer 1 is wound around the take-up drum 7 through the slot 6, ensuring that the positioning protrusion 9 passes through the mesh of the mesh layer 1. Then, the clamping plate is fixed on the positioning protrusion 9 to press and fix the mesh layer 1 onto the take-up drum 7. After the cover plate 11 is fastened at the slot 6, the locking structure is engaged. After contact with the locking structure, the take-up drum 7 is wound up by rotating the shaft 8. When the mesh layer 1 is wound up to the correct position, the shaft 8 is locked by the locking structure, thereby restricting the mesh layer 1. In this scheme, the shaft 8 can be used to adjust the prestress of the mesh layer 1 according to the construction conditions during and after the solidification of the post-cast UHPC concrete, thereby making the crack resistance performance of the reinforced strip after molding more in line with the reinforcement requirements of the existing building 24.

[0028] In this embodiment, the supporting template further includes a steel mesh 12 disposed on the inner wall of the side plate 2. A plurality of anti-pull-out bases 13 are disposed on the steel mesh 12. Each anti-pull-out base 13 has a spherical cavity at its end facing the existing building 24. A connecting ball 14 is movably disposed within the spherical cavity. An adjusting rod 15 facing the existing building 24 is fixed to each connecting ball 14. A rotating sleeve 16 is coaxially threaded to the end of each adjusting rod 15. An anti-pull-out rod 17 is coaxially rotatably connected to the end of each rotating sleeve 16. The end of the rod 17 is hinged with several support rods 19 that are inclined toward the connecting ball 14, and a supporting elastic element 18 is provided between the support rod 19 and the anti-pull rod 17. Several stops 20 are provided on the end of the anti-pull rod 17 to limit the deflection angle of the support rod 19. The connecting member includes several supports 25 embedded in the end plate 3. Bolts are provided between the support 25 and the adjacent end face of the anti-pull seat. Several stepped holes 21 corresponding to the anti-pull rod 17 are opened on the existing building 24. The outer diameter of the stepped hole 21 is smaller than the inner diameter of the inner end.

[0029] After the mesh layer 1 is initially tensioned, the connecting ball 14 is deflected and the adjusting rod 15 is rotated, so that the rotating sleeve 16 and the anti-pull rod 17 at the end of the adjusting rod 15 are inserted into the corresponding stepped hole 21. At this time, the support rod 19 contacts the stepped end face of the stepped hole 21 under the action of the supporting elastic element 18. Then, the adjusting rod 15 is rotated in the opposite direction, and the adjusting rod 15 drives the rotating sleeve 16 and the anti-pull rod 17 to move in the same direction. The support rod 19 is then pushed out by the end face of the stepped hole 21. Then, the end plate 3 is bonded to the side plate 2, and bolts are installed between the support 25 and the corresponding anti-pull seat to strengthen the connection strength between the side plate 2, the end plate 3 and the existing building 24, thereby strengthening the connection strength between the reinforcement strip and the existing building 24 and preventing the reinforcement strip from falling off.

[0030] In this embodiment, a rubber roller 22 parallel to the end of the cover plate 11 is rotatably connected to the end of the cover plate 11.

[0031] By setting rubber rollers 22, the grid layer 1 can be tightly attached to the existing building 24, while also preventing concrete from entering the support shell 5 and preventing the winding drum 7 from rotating.

[0032] In this embodiment, a repair microcapsule (which is prior art and therefore not shown) is also included mixed inside the UHPC concrete. The repair microcapsule uses epoxy resin as its core material.

[0033] When cracks appear in the reinforcement strip, the microcapsules rupture under pressure, releasing the epoxy resin core material. The epoxy resin undergoes a polymerization reaction at a certain temperature to form a cross-linked cured product, thereby filling the crack and achieving self-healing function.

[0034] In this embodiment, self-adhesive epoxy adhesive layers are provided on both sides of the side plate 2.

[0035] By setting a self-adhesive epoxy layer, the connection strength between the existing building 24 and the side panel 2, and between the side panel 2 and the end panel 3 is enhanced. At the same time, the gaps between the existing building 24 and the side panel 2, and between the side panel 2 and the end panel 3 are sealed to prevent leakage of the UHPC concrete poured later.

[0036] In this embodiment, the locking structure includes several limiting protrusions 23 fixed to the end of the rotating shaft 8, and the side plate 2 is provided with limiting grooves that cooperate with the limiting protrusions 23.

[0037] When it is necessary to adjust the prestress of the mesh layer 1, simply pull the rotating shaft 8 outward and rotate it; when it is necessary to fix the rotating shaft 8, slide the rotating shaft 8 downward so that the limiting protrusion 23 is inserted into the corresponding limiting groove. The whole operation process is simple and quick.

[0038] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of the present invention.

Claims

1. A UHPC-FRP composite reinforcement strip for improving the performance of existing structures, characterized in that: The system includes two symmetrically arranged support structures connected to the existing building. A mesh layer, made of FRP material, is bonded to the existing building between adjacent support structures. Each support structure has a winding structure for winding up the corresponding ends of the mesh layer. The system also includes a UHPC material support template, which includes annular side plates and end plates for closing the side plates. The upper end of the inner wall of the side plate is connected to the top of the support structure. The end plates are bonded to the side plates. A grouting groove for pouring UHPC concrete is provided at the top of the side plate.

2. The UHPC-FRP composite reinforcement strip for improving the performance of existing structures according to claim 1, characterized in that: The support structure includes an annular support shell, with slots for the mesh layer to enter and exit on the opposite end faces of adjacent support shells. A cover plate facing the slot is hinged to the side of the support shell away from the existing building. The winding structure includes a winding drum coaxially rotatably connected to the bottom of the support shell. Several positioning protrusions passing through the mesh of the mesh layer are fixed around the circumference of the winding drum. A clamping block is detachably connected to the positioning protrusion. A rotating shaft with its top end penetrating the support shell and extending upward to the side plate is coaxially slidably connected inside the winding drum. A locking structure is provided between the rotating shaft and the side plate.

3. The UHPC-FRP composite reinforcement strip for improving the performance of existing structures according to claim 2, characterized in that: The supporting template also includes a steel mesh installed on the inner wall of the side plate. Several pull-out bases are provided on the steel mesh. Each pull-out base has a spherical cavity at its end facing the existing building. A connecting ball is movably installed within each spherical cavity. An adjusting rod facing the existing building is fixed to each connecting ball. A rotating sleeve is coaxially threaded to the end of each adjusting rod. A pull-out rod is coaxially rotatably connected to the end of each rotating sleeve. Several support rods inclined towards the connecting ball are hinged to the periphery of the end of each pull-out rod, and a supporting elastic element is provided between the support rods and the pull-out rods. Several stops limiting the deflection angle of the support rods are provided on the periphery of the end of each pull-out rod. The connecting component includes several supports embedded in the end plate. Bolts are provided between the supports and adjacent end faces of the pull-out bases. Several stepped holes corresponding to the pull-out rods are opened on the existing building. The outer diameter of each stepped hole is smaller than its inner diameter.

4. The UHPC-FRP composite reinforcement strip for improving the performance of existing structures according to claim 3, characterized in that: The end of the cover plate is rotatably connected to a parallel rubber roller.

5. The UHPC-FRP composite reinforcement strip for improving the performance of existing structures according to claim 4, characterized in that: It also includes repair microcapsules mixed inside the UHPC concrete, the repair microcapsules having an epoxy resin core material.

6. The UHPC-FRP composite reinforcement strip for improving the performance of existing structures according to claim 5, characterized in that: Both sides of the side panel are provided with self-adhesive epoxy adhesive layers.

7. The UHPC-FRP composite reinforcement strip for improving the performance of existing structures according to claim 6, characterized in that: The locking structure includes several limiting protrusions fixed to the end of the rotating shaft, and each side plate is provided with a limiting groove that cooperates with the limiting protrusions.

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