A vacuum-assisted negative pressure grouting device and method for post-tensioned bonded prestressed steel

Abstract

The application belongs to the technical field of prestressed construction of building engineering, and discloses a vacuum-assisted negative pressure grouting device and method for post-tensioned bonded prestressed steel bars, which comprises a grouting system, a vacuum system, and two sealing joints. The grouting system comprises a storage tank, one end of a material conveying pipeline is communicated with a material conveying end of the storage tank, and the other end of the material conveying pipeline is communicated with a grouting hole on a hole sealing plate. The vacuum system comprises a vacuum pump and a negative pressure filtering container, one end of a vacuum pumping pipeline is communicated with a vacuum pumping end of the vacuum pump, the other end of the vacuum pumping pipeline is communicated with a slurry outlet hole on the hole sealing plate through the negative pressure filtering container, and a filtering element is arranged in the negative pressure filtering container. The two sealing joints are respectively used for sealingly connecting the material conveying pipeline and the vacuum pumping pipeline with the grouting hole and the slurry outlet hole. The application effectively prevents the cement slurry from being sucked into the vacuum pump, avoids equipment damage, ensures the absolute sealing of the pipeline interface during the grouting process, improves the fullness and compactness of the hole grouting, and thus guarantees the durability and structural safety of the prestressed steel bars.

Description

Technical Field

[0001] This invention belongs to the field of prestressed construction technology in building engineering, and particularly relates to a vacuum-assisted negative pressure grouting device and method for post-tensioned bonded prestressed steel bars. Background Technology

[0002] With the rapid development of high-speed railway construction, high-speed railway stations, as core facilities of railway transportation hubs, face increasingly stringent requirements for structural safety and durability. Large-span prestressed concrete frame structures are widely used in high-speed railway stations. Post-tensioned bonded prestressing technology, by forming a reliable bond between the prestressing tendons and concrete, enables the prestressing tendons and structural concrete to work together under stress, and is a key technology for ensuring the structural performance of large-span roofs, large-span beams, and slabs. In post-tensioned prestressed structures, after the prestressing tendons are tensioned and anchored, cement grout must be injected into the pre-reserved ducts. Its functions are: firstly, to prevent corrosion of the prestressing tendons and provide chemical protection; and secondly, to bond the prestressing tendons and concrete into a unified whole, ensuring the structure works together under stress. The fullness and density of the grouting in the ducts, from a mechanical perspective, relate to the maximum destructive stress of the prestressing tendons, and from a durability perspective, directly affect the corrosion resistance of the prestressing tendons, making it a decisive factor in the long-term service performance of the prestressed system in high-speed railway stations.

[0003] Vacuum-assisted grouting technology creates a negative pressure environment by evacuating the duct before grouting, effectively improving the compactness of the grout filling. Existing vacuum-assisted grouting devices typically include a vacuum pump, a grout storage tank, and connecting pipelines. In practice, the following main problems exist: 1) During the vacuuming process, moisture, dust, and other impurities in the duct are easily drawn directly into the vacuum pump, causing wear, corrosion, or even damage to the equipment, affecting its lifespan and grouting effect; 2) Poor sealing at the connection between the grouting pipeline and the grouting holes and outlet holes on the duct sealing plate easily leads to air and grout leakage under negative or positive pressure conditions, resulting in the inability to maintain vacuum or grout loss, severely impacting grouting quality.

[0004] Therefore, there is an urgent need for a vacuum-assisted negative pressure grouting device and method for post-tensioned bonded prestressed steel bars to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a vacuum-assisted negative pressure grouting device and method for post-tensioned bonded prestressed steel bars, so as to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides the following solution: The present invention provides a vacuum-assisted negative pressure grouting device for post-tensioned bonded prestressed steel bars, comprising: The grouting system includes a storage tank in which the prepared cement grout is stored. One end of the storage tank is connected to a conveying pipe, and the other end of the conveying pipe is connected to a grouting hole on a duct sealing plate. A vacuum system includes a vacuum pump and a negative pressure filter container. The vacuum pump's vacuuming end is connected to one end of a vacuuming pipe, and the other end of the vacuuming pipe is connected to the slurry outlet on the channel sealing plate through the negative pressure filter container. A filter element is installed inside the negative pressure filter container. Two sealing joints are respectively installed on the material conveying pipe and the vacuuming pipe. The material conveying pipe and the vacuuming pipe are respectively sealed to the grouting hole and the grout outlet hole through the sealing joints.

[0007] Preferably, the sealing joint includes a fixed pipe, which is fixedly connected to the material conveying pipe and the vacuuming pipe. An annular groove is formed at the bottom of the outer wall of the fixed pipe, and a bottom clamping member is provided in the annular groove. A top clamping ring is fitted at the top of the outer wall of the fixed pipe. The fixed pipe is limited and connected to the duct sealing plate through the top clamping ring and the bottom clamping member. A sealing member is provided on the outer wall of the fixed pipe. When the top clamping ring slides downward, it drives the sealing member to contact the inner wall of the grouting hole and the grout outlet hole.

[0008] Preferably, the bottom clamping member includes multiple rotating shafts that are rotatably connected in the annular groove at equal intervals along the circumference. One end of the bottom clamping plate is fixedly connected to the rotating shaft. Multiple control components are arranged in the fixed tube along the circumference. The control components are used to control the rotation of the rotating shaft.

[0009] Preferably, the control component includes a rotating rod rotatably connected to the fixed tube, the bottom end of the rotating rod extending into the annular groove and fixedly connected to a first gear, a second gear fixedly connected to the rotating shaft, the first gear meshing with the second gear, and a threaded rod fixedly connected to the top end of the rotating rod, the top end of the threaded rod passing through the top clamping ring and threadedly connected to the top clamping ring.

[0010] Preferably, a third gear is fixedly connected to the top of the threaded rod, a control ring is rotatably connected to the fixed tube, and an annular toothed plate is fixedly connected to the inner side wall of the control ring, with the third gear meshing with the annular toothed plate.

[0011] Preferably, the sealing element includes a sealing inflatable rubber ring fixedly connected to the outer wall of the fixed tube, and a plurality of sealing cavities are opened inside the fixed tube. The bottom end of the sealing cavity is connected to the sealing inflatable rubber ring through a channel. A rubber plug is slidably connected inside the sealing cavity. A connecting rod is fixedly connected to the top end of the rubber plug. The top end of the connecting rod extends out of the fixed tube and is fixedly connected to the bottom end of the top clamping ring.

[0012] Preferably, a sliding rod is provided inside the sealing cavity, the sliding rod is slidably connected to the channel, one end of the sliding rod extends into the sealing inflatable rubber ring and is fixedly connected to an arc-shaped top plate, the other end of the sliding rod is located inside the sealing cavity and is fixedly connected to a toggle block, and the bottom end of the rubber plug is fixedly connected to a toggle plate, the toggle plate being adapted to the toggle block.

[0013] Preferably, a return spring is sleeved on the sliding rod, and the two ends of the return spring are fixedly connected to the arc-shaped top plate and the channel, respectively; the two adjacent arc-shaped top plates are staggered.

[0014] Preferably, the filter element includes multiple filter frames, which are fixedly connected circumferentially inclined within the negative pressure filter container, and filter screens are fixedly connected within each filter frame.

[0015] A vacuum-assisted negative pressure grouting method for post-tensioned bonded prestressed steel bars includes the following steps: The sealing joint on the material conveying pipe is sealed to the grouting hole on the duct sealing plate, and the sealing joint on the vacuum pipe is sealed to the grout outlet hole on the duct sealing plate. Start the vacuum pump to evacuate the channel and create a negative pressure inside the channel; Grout is injected into the grouting hole through the storage tank; When cement slurry is observed to flow continuously from the outlet hole, the vacuum pump is turned off, and grouting continues until the preset pressure is reached or until the slurry discharged from the outlet hole is consistent with the injected slurry, at which point grouting is stopped.

[0016] Compared with the prior art, the present invention has the following advantages and technical effects: This invention provides a vacuum-assisted negative pressure grouting device and method for post-tensioned bonded prestressed steel bars. By incorporating a negative pressure filter container and its internal filter elements, moisture, dust, and other impurities within the ducts are effectively intercepted during vacuuming, preventing them from entering the vacuum pump and thus avoiding equipment damage. Two sealing joints are respectively connected to the grouting hole and the grout outlet, ensuring absolute sealing of the pipe interfaces throughout the grouting process. This significantly improves the fullness and density of the grouting in the ducts, ensuring the bonding quality and durability of the prestressed tendons. This invention effectively prevents cement slurry from being sucked into the vacuum pump, avoiding equipment damage, ensuring absolute sealing at the pipe interfaces during grouting, and improving the fullness and density of the grouting in the ducts, thereby guaranteeing the durability of the prestressed tendons and structural safety. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the sealing joint structure of the present invention; Figure 3 For the present invention Figure 2 Enlarged view of a portion of point A in the middle; Figure 4 For the present invention Figure 2 Enlarged view of a section at point B in the middle; Figure 5 This is a schematic diagram of the internal structure of the negative pressure filter container of the present invention; The components include: 1. Storage tank; 2. Conveying pipe; 3. Channel sealing plate; 4. Grouting hole; 5. Vacuum pump; 6. Vacuum extraction pipe; 7. Grout outlet; 8. Fixed pipe; 9. Annular groove; 10. Top clamping ring; 11. Rotating shaft; 12. Bottom clamping plate; 13. Rotating rod; 14. First gear; 15. Second gear; 16. Threaded rod; 17. Third gear; 18. Control ring; 19. Annular toothed plate; 20. Sealing inflatable rubber ring; 21. Sealing cavity; 22. Channel; 23. Connecting rod; 24. Sliding rod; 25. Arc-shaped top plate; 26. Actuating block; 27. Actuating plate; 28. Return spring; 29. ​​Rubber plug; 30. Negative pressure filter container; 31. Filter frame; 32. Filter screen. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] Reference Figures 1-5 This invention provides a vacuum-assisted negative pressure grouting device for post-tensioned bonded prestressed steel bars, comprising: The grouting system includes a storage tank 1, in which the prepared cement grout is stored. One end of the storage tank 1 is connected to a conveying pipe 2, and the other end of the conveying pipe 2 is connected to a grouting hole 4 on a duct sealing plate 3. The vacuum system includes a vacuum pump 5 and a negative pressure filter container 30. The vacuum pump 5 is connected to one end of a vacuum pipe 6, and the other end of the vacuum pipe 6 is connected to the slurry outlet 7 on the channel sealing plate 3 through the negative pressure filter container 30. A filter element is installed inside the negative pressure filter container 30. Two sealing joints are respectively installed on the material conveying pipe 2 and the vacuum pipe 6. The material conveying pipe 2 and the vacuum pipe 6 are respectively sealed to the grouting hole 4 and the grout outlet hole 7 through the sealing joints.

[0022] In one embodiment of the present invention, by setting a negative pressure filter container 30 and its internal filter elements, moisture, dust and other impurities in the duct are effectively intercepted during vacuuming, preventing them from entering the vacuum pump and avoiding equipment damage. The two sealing joints are respectively sealed to the grouting hole 4 and the grout outlet hole 7, ensuring the absolute sealing of the pipeline interface throughout the grouting process, thereby significantly improving the fullness and density of the grouting in the duct, and ensuring the bonding quality and durability of the prestressing tendons.

[0023] As an optional implementation, the sealing joint includes a fixed pipe 8, which is fixedly connected to the material conveying pipe 2 and the vacuum pipe 6. An annular groove 9 is provided at the bottom of the outer wall of the fixed pipe 8, and a bottom clamping member is provided in the annular groove 9. A top clamping ring 10 is sleeved on the top of the outer wall of the fixed pipe 8. The fixed pipe 8 is limited and connected to the duct sealing plate 3 through the top clamping ring 10 and the bottom clamping member. A sealing member is provided on the outer wall of the fixed pipe 8. When the top clamping ring 10 slides downward, it drives the sealing member to contact the inner wall of the grouting hole 4 and the grout outlet hole 7.

[0024] In one embodiment of the present invention, the top clamping ring 10 cooperates with the bottom clamping member to achieve a quick limiting connection between the sealing joint and the hole sealing plate. When the top clamping ring 10 slides downward, it simultaneously drives the sealing member to make tight contact with the inner wall of the grouting hole 4 or the grout outlet hole 7 to achieve sealing.

[0025] As an optional implementation, the bottom clamping member includes multiple rotating shafts 11, which are rotatably connected in the annular groove 9 at equal intervals along the circumference. One end of the bottom clamping plate 12 is fixedly connected to the rotating shaft 11. Multiple control components are arranged in the fixed tube 8 along the circumference. The control components are used to control the rotation of the rotating shaft 11.

[0026] In one embodiment of the present invention, the bottom clamping plate 12 can rotate around the rotating shaft 11 and unfold from the annular groove 9 under the drive of the control component, hooking from the inside of the channel sealing plate, forming a bidirectional clamping structure with the outer top clamping ring.

[0027] As an optional implementation, the control component includes a rotating rod 13 rotatably connected to the fixed tube 8. The bottom end of the rotating rod 13 extends into the annular groove 9 and is fixedly connected to a first gear 14. A second gear 15 is fixedly connected to the rotating shaft 11. The first gear 14 and the second gear 15 mesh. A threaded rod 16 is fixedly connected to the top end of the rotating rod 13. The top end of the threaded rod 16 passes through the top clamping ring 10 and is threadedly connected to the top clamping ring 10.

[0028] In one embodiment of the present invention, the rotational motion of the threaded rod 16 is simultaneously converted into the axial movement of the top clamping ring 10 and the rotation of the bottom clamping plate 12.

[0029] As an optional implementation, a third gear 17 is fixedly connected to the top of the threaded rod 16, a control ring 18 is rotatably connected to the fixed tube 8, and an annular toothed plate 19 is fixedly connected to the inner side wall of the control ring 18, with the third gear 17 meshing with the annular toothed plate 19.

[0030] In one embodiment of the present invention, by rotating the control ring 18, the annular gear plate 19 simultaneously drives all the third gears 17 to rotate synchronously.

[0031] As an optional implementation, the sealing element includes a sealing inflatable rubber ring 20 fixedly connected to the outer wall of the fixed tube 8. The fixed tube 8 has multiple sealing cavities 21. The bottom end of the sealing cavity 21 communicates with the sealing inflatable rubber ring 20 through a channel 22. A rubber plug 29 is slidably connected in the sealing cavity 21. A connecting rod 23 is fixedly connected to the top end of the rubber plug 29. The top end of the connecting rod 23 extends out of the fixed tube 8 and is fixedly connected to the bottom end of the top clamping ring 10.

[0032] In one embodiment of the present invention, when the top clamping ring 10 slides downward, compressed air enters the sealing inflatable rubber ring 20 through the channel, causing it to expand radially and fit tightly against the inner wall of the channel, thereby achieving a seal.

[0033] As an optional implementation, a sliding rod 24 is provided in the sealing cavity 21. The sliding rod 24 is slidably connected to the channel 22. One end of the sliding rod 24 extends into the sealing inflatable rubber ring 20 and is fixedly connected to an arc-shaped top plate 25. The other end of the sliding rod 24 is located in the sealing cavity 21 and is fixedly connected to a toggle block 26. A toggle plate 27 is fixedly connected to the bottom end of the rubber plug 29. The toggle plate 27 is adapted to the toggle block 26.

[0034] In one embodiment of the present invention, when the rubber stopper 29 moves down, the actuating plate 27 at its bottom pushes the actuating block 26, causing the sliding rod 24 to drive the arc-shaped top plate 25 to further compress the sealing inflatable rubber ring 20 from the inside, further ensuring stable contact between the sealing inflatable rubber ring 20 and the inner wall of the channel, forming a tighter fit, enhancing the sealing ability, and at the same time avoiding deformation of the sealing inflatable rubber ring 20 after long-term use, which would affect the sealing effect.

[0035] As an optional implementation, a return spring 28 is sleeved on the sliding rod 24, and the two ends of the return spring 28 are fixedly connected to the arc-shaped top plate 25 and the channel 22 respectively; the two adjacent arc-shaped top plates 25 are staggered.

[0036] In one embodiment of the present invention, the reset spring 28 can automatically return the sliding rod 24 to its original position after the pressure is released, and the adjacent arc-shaped top plates 25 are staggered and in contact, ensuring the sealing of the overall structure.

[0037] As an optional implementation, the filter element includes a plurality of filter frames 31, which are fixedly connected in a circumferentially inclined manner within the negative pressure filter container 30, and a filter screen 32 is fixedly connected inside the filter frame 31.

[0038] In one embodiment of the present invention, the inclined arrangement of the filter screen 32 facilitates the deposition of intercepted water and impurities downward along the filter screen, making it less likely to clog the mesh and ensuring smooth airflow during the vacuuming process.

[0039] A vacuum-assisted negative pressure grouting method for post-tensioned bonded prestressed steel bars includes the following steps: Seal the sealing joint on the material conveying pipe 2 to the grouting hole 4 on the duct sealing plate 3, and seal the sealing joint on the vacuum pipe 6 to the grout outlet hole 7 on the duct sealing plate 3. Start vacuum pump 5 to evacuate the channel and create a negative pressure inside the channel; Grouting is performed through storage tank 1 into grouting hole 4; When cement slurry is observed to flow continuously from the slurry outlet 7, turn off the vacuum pump 5 and continue grouting to the preset pressure or until the slurry discharged from the slurry outlet 7 is consistent with the injected slurry, then stop grouting.

[0040] In one embodiment of the present invention, before grouting, the sealing joints at the ends of the material conveying pipe 2 and the vacuum pipe 6 are first inserted into the grouting hole 4 and the grout outlet hole 7 of the duct sealing plate 3, respectively. The operator manually rotates the control ring 18, and the annular toothed plate 19 drives all the third gears 17 to rotate synchronously, thereby driving the threaded rod 16 and the rotating rod 13 to rotate. The rotating rod 13 drives the rotating shaft 11 to rotate through the first gear 14 and the second gear 15, causing the bottom clamping plate 12 to unfold from the annular groove 9 and hook onto the duct sealing plate 3 from the inside. At the same time, due to the threaded engagement between the threaded rod 16 and the top clamping ring 10, the top clamping ring 10 slides downward and is pressed from the outside of the duct sealing plate 3, achieving bidirectional clamping and fixing.

[0041] As the top clamping ring 10 moves downward, the connecting rod 23 pushes the rubber plug 29 downward within the sealing cavity 21, compressing the air inside. The air then enters the sealing inflatable rubber ring 20 through the channel 22, causing it to expand and come into close contact with the inner wall of the grouting hole 4 or the grout outlet 7. As the rubber plug 29 moves downward, its bottom actuating plate 27 contacts and pushes the actuating block 26, causing the sliding rod 24 to move towards the center. This, in turn, causes the arc-shaped top plate 25 to compress the sealing inflatable rubber ring 20, resulting in more complete radial expansion and thus achieving multi-stage, high-efficiency sealing.

[0042] After the sealing joint is installed, vacuum pump 5 is started to evacuate the prestressed duct. The extracted gas and impurities pass through negative pressure filter container 30, and the impurities are intercepted by filter screen 32. When the required vacuum level is reached, the grouting system is started, and cement grout is injected from storage tank 1 into grouting hole 4 through material delivery pipe 2. Under negative pressure, the grout is quickly drawn into the duct. When a continuous and full flow of grout is observed from grout outlet 7, vacuum pump 5 is turned off, and pressure grouting continues until the preset pressure is reached or the grout discharged from grout outlet 7 is consistent with the injected grout. Finally, the grouting valve is closed to complete the grouting operation.

[0043] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", 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 this invention, and are not intended to 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 this invention.

[0044] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A vacuum-assisted negative pressure grouting device for post-tensioned bonded prestressed steel bars, characterized in that, include: The grouting system includes a storage tank (1), in which the prepared cement slurry is stored. One end of the storage tank (1) is connected to a conveying pipe (2), and the other end of the conveying pipe (2) is connected to a grouting hole (4) on a duct sealing plate (3). The vacuum system includes a vacuum pump (5) and a negative pressure filter container (30). The vacuum pump (5) has a vacuum end connected to one end of a vacuum pipe (6). The other end of the vacuum pipe (6) is connected to the slurry outlet (7) on the channel sealing plate (3) through the negative pressure filter container (30). The negative pressure filter container (30) is equipped with a filter element. Two sealing joints are respectively installed on the material conveying pipe (2) and the vacuum pipe (6). The material conveying pipe (2) and the vacuum pipe (6) are respectively sealed to the grouting hole (4) and the grout outlet (7) through the sealing joints.

2. The vacuum-assisted negative pressure grouting device for post-tensioned bonded prestressed steel bars according to claim 1, characterized in that: The sealing joint includes a fixed tube (8), which is fixedly connected to the material conveying pipe (2) and the vacuum pipe (6). An annular groove (9) is provided at the bottom of the outer wall of the fixed tube (8). A bottom clamping member is provided in the annular groove (9). A top clamping ring (10) is sleeved on the top of the outer wall of the fixed tube (8). The fixed tube (8) is limited and connected to the hole sealing plate (3) through the top clamping ring (10) and the bottom clamping member. A sealing member is provided on the outer wall of the fixed tube (8). When the top clamping ring (10) slides down, it drives the sealing member to contact the inner wall of the grouting hole (4) and the grout outlet hole (7).

3. The vacuum-assisted negative pressure grouting device for post-tensioned bonded prestressed steel bars according to claim 2, characterized in that: The bottom clamping component includes multiple rotating shafts (11) that are rotatably connected in the annular groove (9) at equal intervals along the circumference. One end of the bottom clamping plate (12) is fixedly connected to the rotating shaft (11). Multiple control components are arranged in the fixed tube (8) along the circumference. The control components are used to control the rotation of the rotating shaft (11).

4. The vacuum-assisted negative pressure grouting device for post-tensioned bonded prestressed steel bars according to claim 3, characterized in that: The control component includes a rotating rod (13) rotatably connected to the fixed tube (8), the bottom end of the rotating rod (13) extending into the annular groove (9) and fixedly connected to a first gear (14), a second gear (15) fixedly connected to the rotating shaft (11), the first gear (14) meshing with the second gear (15), and a threaded rod (16) fixedly connected to the top end of the rotating rod (13), the top end of the threaded rod (16) passing through the top clamping ring (10) and threadedly connected to the top clamping ring (10).

5. The vacuum-assisted negative pressure grouting device for post-tensioned bonded prestressed steel bars according to claim 4, characterized in that: The top end of the threaded rod (16) is fixedly connected to a third gear (17), and a control ring (18) is rotatably connected to the fixed tube (8). An annular toothed plate (19) is fixedly connected to the inner side wall of the control ring (18), and the third gear (17) meshes with the annular toothed plate (19).

6. The vacuum-assisted negative pressure grouting device for post-tensioned bonded prestressed steel bars according to claim 2, characterized in that: The sealing element includes a sealing inflatable rubber ring (20) fixedly connected to the outer wall of the fixed tube (8). The fixed tube (8) has multiple sealing cavities (21). The bottom end of the sealing cavity (21) is connected to the sealing inflatable rubber ring (20) through a channel (22). A rubber plug (29) is slidably connected in the sealing cavity (21). A connecting rod (23) is fixedly connected to the top end of the rubber plug (29). The top end of the connecting rod (23) extends out of the fixed tube (8) and is fixedly connected to the bottom end of the top clamping ring (10).

7. A vacuum-assisted negative pressure grouting device for post-tensioned bonded prestressed steel bars according to claim 6, characterized in that: A sliding rod (24) is provided inside the sealing cavity (21). The sliding rod (24) is slidably connected to the channel (22). One end of the sliding rod (24) extends into the sealing inflatable rubber ring (20) and is fixedly connected to an arc-shaped top plate (25). The other end of the sliding rod (24) is located inside the sealing cavity (21) and is fixedly connected to a toggle block (26). The bottom end of the rubber plug (29) is fixedly connected to a toggle plate (27), and the toggle plate (27) is adapted to the toggle block (26).

8. The vacuum-assisted negative pressure grouting device for post-tensioned bonded prestressed steel bars according to claim 7, characterized in that: A reset spring (28) is sleeved on the sliding rod (24), and the two ends of the reset spring (28) are fixedly connected to the arc-shaped top plate (25) and the channel (22) respectively; the two adjacent arc-shaped top plates (25) are staggered.

9. A vacuum-assisted negative pressure grouting device for post-tensioned bonded prestressed steel bars according to claim 1, characterized in that: The filter element includes multiple filter frames (31), which are fixedly connected in a circumferential direction within the negative pressure filter container (30), and a filter screen (32) is fixedly connected inside the filter frame (31).

10. A method for vacuum-assisted negative pressure grouting of post-tensioned bonded prestressed steel bars, applicable to the vacuum-assisted negative pressure grouting device for post-tensioned bonded prestressed steel bars as described in claim 1, characterized in that... Includes the following steps: The sealing joint on the material conveying pipe (2) is sealed to the grouting hole (4) on the duct sealing plate (3), and the sealing joint on the vacuum pipe (6) is sealed to the grout outlet hole (7) on the duct sealing plate (3). Start the vacuum pump (5) to evacuate the channel and create a negative pressure inside the channel; Grouting is performed through the storage tank (1) into the grouting hole (4); When cement slurry is observed to flow continuously from the slurry outlet (7), the vacuum pump (5) is turned off, and grouting continues until the preset pressure is reached or until the slurry discharged from the slurry outlet (7) is consistent with the injected slurry, and then grouting is stopped.

Images