Grouting type unbonded prestress system and construction method and tension supplementing method thereof

Abstract

The invention discloses a grouting type unbonded prestressed system, belongs to the technical field of unbonded prestressed systems, and solves the problem of unsmooth circulation of an anticorrosive medium of an existing prestressed system. The device comprises a protective cover, an anchor plate, a clamping piece, an anchor bearing plate and an unbonded rib, a sinking table is arranged on the side, close to the anchor bearing plate, of the anchor plate, a plurality of through grooves penetrating to the peripheral face of the anchor plate in the radial direction are formed in the portion, on the outer side of the sinking table, of the anchor plate, each through groove is communicated with a circulation hole, the circulation holes penetrate to the other side of the anchor plate, and the clamping piece is arranged on the other side of the anchor plate. Gaps are formed between the other side face and the peripheral face of the anchor plate and the inner wall of the protective cover, and the anchor plate is provided with an installation structure used for installing a pressure-bearing piece during supplementary tensioning. According to the grouting type unbonded prestress system, an anti-corrosion medium can be quickly and uniformly distributed at each corner of an anchorage device, and long-term effective corrosion prevention is provided. The invention further discloses a construction method and a supplementary tensioning method of the grouting type unbonded prestress system.

Description

Technical Field

[0001] The invention relates to the technical field of non-bonded prestressed system, and more specifically, to a grouting type non-bonded prestressed system and a construction method and a tensioning method thereof. Background Art

[0002] At present, the prestressed anchoring system is mainly divided into bonded and non-bonded systems. The bonded anchoring system uses grouting to bond the steel strands to the structure to form a structural whole. The non-bonded anchoring system uses non-bonded bars. The outer PE sleeve of the non-bonded bars is filled with grease, so that the steel strands can slide in the PE sleeve, which can achieve a smaller friction loss. However, conventional non-bonded bars need to be cast together with concrete, which has a greater impact on large components or components cast in sections. In short, the friction loss of bonded prestressing is large, and the non-bonded construction is inconvenient.

[0003] In the field of civil engineering, especially in the field of third-generation nuclear power prestressed containment technology, the use of a non-bonded prestressing system can reduce the friction resistance of the prestressed beam, increase the effective prestress in the component, and shorten the nuclear power construction period. During the operation period of the component, if the steel strands are loose, the prestressed beams can be re-tensioned to extend the life cycle of the containment.

[0004] In the existing unbonded prestressed system, the bottom groove of the anchor plate is connected to the protective cover only through the anchor hole. After the steel strands and clips are installed, it is difficult for the anti-corrosion medium to enter the bottom groove, making the construction extremely inconvenient.

[0005] Therefore, there is an urgent need to develop and design a grouting type non-bonded prestressed system and its construction method and tensioning method. Summary of the invention

[0006] The technical problem to be solved by the present invention is to address the above-mentioned deficiencies in the prior art. One purpose of the present invention is to provide a grouting type bondless prestressed system so that the anti-corrosion medium can be quickly and evenly distributed in every corner of the anchor, providing long-term and effective anti-corrosion.

[0007] The second purpose of the present invention is to provide a grouting type non-bonded prestressed system construction method, which can first thread the prestressed duct, grout and then tension it, adjust the inherent non-bonded prestressed system construction sequence, and improve the construction efficiency under specific working conditions.

[0008] The third purpose of the present invention is to provide a method for replenishing the prestress of a grouting-type non-bonded prestressed system, which can replenish the prestress of the structure and improve the durability of the structure after several years of operation or when the prestress relaxation does not meet the working conditions.

[0009] In order to achieve the above-mentioned purpose one, the present invention provides a grouting type non-bonded prestressed system, including a protective cover, an anchor plate, a clip, an anchor plate and non-bonded tendons, the protective cover is installed at one end of the anchor plate, the anchor plate is located in the protective cover, the non-bonded tendons penetrate the anchor plate, the anchor plate extends into the protective cover, and the steel strands of the non-bonded tendons are connected and fixed to the anchor plate through the clips, a sinking platform is provided on the side of the anchor plate close to the anchor plate, and a plurality of through grooves radially penetrating to the outer peripheral surface of the anchor plate are opened on the anchor plate outside the sinking platform, each of the through grooves is connected to a flow hole, and the flow hole penetrates to the other side of the anchor plate, the other side surface and the outer peripheral surface of the anchor plate have a gap with the inner wall of the protective cover, and the anchor plate is provided with a mounting structure for installing pressure-bearing parts during tensioning.

[0010] As a further improvement, the protective cover is a stepped structure, and the anchor plate is located inside the larger end of the protective cover.

[0011] Furthermore, the larger end of the protective cover is connected to the anchor plate via a plurality of connecting screws, and a sealing ring is provided between the protective cover and the anchor plate.

[0012] In order to achieve the above-mentioned second objective, the present invention provides a grouting type non-bonded prestressed system construction method, including the above-mentioned grouting type non-bonded prestressed system, the method comprising the following steps:

[0013] S1. Install the anchor plate and prestressed pipe according to the design drawings and then pour concrete;

[0014] S2, insert the unbonded reinforcement into the anchor plate and the prestressed hole;

[0015] S3. After the concrete strength reaches the tensioning condition, the unbonded reinforcement positioning and grouting sealing structure is installed at the end of the anchor plate, and the prestressed duct is grouted;

[0016] S4. After the slurry strength in the prestressed duct reaches the design strength, the unbonded reinforcement positioning and grouting sealing structure are removed, and the PE sleeve of the exposed unbonded reinforcement is peeled off;

[0017] S5. Install anchor plates, clips, and tensioning equipment to tension the steel strands without bonding reinforcement. After tensioning, remove the tensioning equipment and cut off the excess steel strands to keep a certain length.

[0018] S6. Install the protective cover and inject soluble anti-corrosion medium into the protective cover.

[0019] As a further improvement, the bondless rib positioning and grouting sealing structure includes a sealing plate and a pressure plate, the pressure plate is provided with a plurality of through holes equal to the number of the bondless ribs, and a plurality of sealing plugs equal to the number of the bondless ribs are detachably installed on one side of the pressure plate, the sealing plate is provided with a plurality of conical holes equal to the number of the bondless ribs, and the largest end of the conical hole is arranged toward the side of the sealing plug, the pressure plate and the sealing plate are detachably connected, and when the pressure plate and the sealing plate are connected, the center lines of the plurality of sealing plugs, the conical holes and the through holes coincide one by one, and a sealing ring is provided on the side of the sealing plate away from the pressure plate.

[0020] Furthermore, the pressure plate is provided with a plurality of positioning screws, and the plurality of positioning screws all penetrate the pressure plate and are threadedly connected with the sealing plate.

[0021] Furthermore, the sealing plate is provided with a loosening component which can loosen it, and a connecting component which can connect and lock the pressing plate and the sealing plate or loosen and separate them is provided between the pressing plate and the sealing plate.

[0022] Furthermore, each sealing plug is provided with a step with a diameter larger than the diameter of the sealing plug at one end close to the pressure plate, and each pressure plate corresponding to the outer edge of the through hole is provided with a recessed groove matched with the step. A fixing plate is installed on one side of the pressure plate by fastening screws, and the fixing plate is provided with a plurality of through holes with the same number and outer diameter as the sealing plugs. When the fixing plate is installed on the pressure plate, the fixing plate presses the step tightly in the recessed groove.

[0023] In order to achieve the third objective, the present invention provides a method for tensioning a grouting type non-bonded prestressed system, characterized in that it comprises the above-mentioned grouting type non-bonded prestressed system, the mounting structure is an external thread arranged on the outer peripheral surface of the anchor plate, the pressure bearing member is a support nut, and the method comprises the following steps:

[0024] S1. Remove the protective cover and install the support nut on the anchor plate;

[0025] S2. Install the tensioning machine to supplement the exposed steel strands without bonding reinforcement. When the tensioning machine tensions the steel strands to the specified force value, the anchor plate will be separated from the end face of the anchor pad, and the support nut will be screwed and fitted to the end face of the anchor pad;

[0026] S4. Remove the tensioning equipment. At this time, the support nuts will support the anchor plate and maintain the prestress.

[0027] S5. Install the protective cover on the supporting nut and inject soluble anti-corrosion medium.

[0028] As a further improvement, a sealing ring is installed at one end of the support nut, and a connecting ring is provided at the other end of the support nut. The connecting ring is provided with a plurality of connecting holes, and the positions of the plurality of connecting holes correspond one-to-one to the hole positions of the anchor plate.

[0029] Beneficial Effects

[0030] Compared with the prior art, the present invention has the following advantages:

[0031] 1. The prestressed system of the present invention allows a certain length to be reserved when stripping the PE sleeve by arranging a sinking platform on the anchor plate, which greatly facilitates the construction of stripping the PE sleeve and improves efficiency. The reserved length of the PE sleeve is conducive to the subsequent replacement of the steel strand with the help of this section of the PE sleeve for sealing. At the same time, through grooves and flow holes are arranged on the anchor plate to connect the two sides of the anchor plate, so that the anti-corrosion medium can be quickly and evenly distributed in every corner of the anchor, providing long-term and effective anti-corrosion.

[0032] 2. The prestressed system construction method of the present invention can first thread the prestressed duct, grout it and then tension it, adjust the inherent construction sequence of the non-bonded prestressed system, and improve the construction efficiency under specific working conditions.

[0033] 3. The unbonded rib positioning and grouting sealing structure used in the present invention is characterized by providing sealing units equal in number to the unbonded ribs. The sealing units are transformed from a whole rubber plate into a combination of several sealing plugs and tapered holes, thereby achieving independent sealing of a single unbonded rib, less deformation, more uniform deformation, better sealing effect, and the ability to withstand higher grouting pressure without leakage. The tapered hole is automatically centered, which can effectively improve the positioning accuracy of the unbonded ribs and the sealing effect during grouting.

[0034] 4. The prestressing system replenishing method of the present invention can replenish the prestress after several years of operation or when the prestress relaxation does not meet the working condition requirements, supplement the structural prestress and improve the durability of the structure.

[0035] 5. The prestressed system re-tensioning method of the present invention adopts a structure in which a support nut supports a protective cover, which can reduce the infusion of soluble anti-corrosion media during the first tensioning. After the re-tensioning, the protective cover is installed on the support nut, and there is no need to replace the protective cover, which can reduce costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a structural schematic diagram of the present invention;

[0037] Figure 2 for Figure 1 A schematic diagram of the structure enlargement at the center A;

[0038] Figure 3 It is a structural schematic diagram of the present invention when installing the non-bonded reinforcement positioning and grouting sealing structure;

[0039] Figure 4 This is a schematic diagram of the structure after the present invention is supplemented;

[0040] Figure 5 for Figure 4 A schematic diagram of the structure enlarged at B in the middle;

[0041] Figure 6 It is a three-dimensional structural schematic diagram of the non-bonded rib positioning and grouting sealing structure of the present invention;

[0042] Figure 7 It is an enlarged schematic diagram of the main view of the partial cross-section structure of the non-bonded reinforcement positioning and grouting sealing structure in the present invention.

[0043] Figure 8 It is an enlarged schematic diagram of the main structure of the sealing plug in the present invention;

[0044] Fig. 9 It is an enlarged schematic diagram of the main structure of another embodiment of the non-bonded rib positioning and grouting sealing structure of the present invention;

[0045] Fig.10 It is an enlarged schematic diagram of the main structure of another embodiment of the non-bonded rib positioning and grouting sealing structure of the present invention;

[0046] Fig.11 It is an enlarged schematic diagram of the three-dimensional structure of one side of the anchor plate in the present invention;

[0047] Fig.12 It is an enlarged schematic diagram of the three-dimensional structure of the other side of the anchor plate in the present invention;

[0048] Fig.13 It is an enlarged schematic diagram of the three-dimensional structure of the support nut in the present invention;

[0049] Fig.14 An enlarged schematic diagram of the main structure of another embodiment of the non-bonded rib positioning and grouting sealing structure of the present invention;

[0050] Fig.15 for Fig.14 Enlarged schematic diagram of the structure at C in the middle.

[0051] Among them: 1-protective cover, 2-anchor plate, 3-clip, 4-anchor pad, 5-grouting connector, 6-unbonded ribs, 7-connecting screws, 8-sealing ring, 9-soluble anti-corrosion medium, 10-sealing plate, 11-pressure plate, 12-through hole, 13-sealing plug, 14-tapered hole, 15-positioning screw, 16-loosening screw, 17-loosening nut, 18-handle, 19-fastening screw, 20-fixing plate, 21-support nut, 22-bolt hole, 23-pressing screw, 24-connecting column, 25-locking nut, 26-annular limiting groove, 27-limiting ring, 131-step, 132-tapered surface, 201-sinking platform, 202-through groove, 203-flow hole, 211-connecting ring, 212-connecting hole. DETAILED DESCRIPTION

[0052] The present invention will be further described below with reference to the specific embodiments in the accompanying drawings.

[0053] See also Figure 1-2 , 11-12, a grouting type bondless prestressed system of the present invention comprises a protective cover 1, an anchor plate 2, a clip 3, an anchor plate 4 and bondless tendons 6, wherein the protective cover 1 is installed at one end of the anchor plate 4, the anchor plate 2 is located in the protective cover 1, plays a role in protecting the anchor plate 2 to prevent rust, the bondless tendons 6 penetrate the anchor plate 4, the anchor plate 2 extends into the protective cover 1, the anchor plate 2 is provided with a plurality of tapered holes matching the number of bondless tendons 6, for installing the clip 3, and the steel strands of the bondless tendons 6 are connected and fixed to the anchor plate 2 through the clip 3, so as to realize the anchoring of the bondless tendons 6. A sinker 201 is provided on one side of the anchor plate 2 close to the anchor pad 4. The sinker 201 is a groove axially recessed from the side of the anchor plate 2. By providing the sinker 201 on the anchor plate 2, a certain length is allowed to be reserved when stripping the PE sleeve, which greatly facilitates the construction of stripping the PE sleeve and improves efficiency. Reserving a certain length of the PE sleeve is conducive to sealing with the help of this section of the PE sleeve when the steel strand is replaced later. A plurality of through grooves 202 radially penetrating to the outer peripheral surface of the anchor plate 2 are opened on the anchor plate 2 outside the sinker 201 for the flow of anti-corrosion medium. Each through groove 202 is connected to a flow hole 203 for the flow of anti-corrosion medium. The flow hole 203 penetrates to the other side of the anchor plate 2. There is a gap between the other side and the outer peripheral surface of the anchor plate 2 and the inner wall of the protective cover 1. On the one hand, the flow area of ​​the anti-corrosion medium is increased, the flow of the anti-corrosion medium is further accelerated, and it is dispersed in various corners to improve the anti-corrosion effect; on the other hand, there is a gap on the outer peripheral surface of the anchor plate 2, and the support nut 21 is installed when it is subsequently supplemented. The anchor plate 2 is provided with a mounting structure for mounting a pressure-bearing member during supplementary tensioning.

[0054] The prestressed system of the present invention connects the two sides of the anchor plate 2 by arranging the through groove 202 and the flow hole 203 on the anchor plate 2, so that the anti-corrosion medium can be quickly and evenly distributed in every corner of the anchor, providing long-term and effective anti-corrosion.

[0055] Preferably, the protective cover 1 is a stepped structure, wherein the anchor is located inside the larger end of the protective cover 1. That is, the protective cover 1 is a segmented protective cover. In combination with the actual shape of the anchor, the inner diameter of the protective cover 1 in the anchor plate section is greater than or equal to the outer diameter of the anchor plate 2, and in the steel strand section without bonding ribs, the inner diameter of the protective cover 1 is greater than or equal to the maximum outer diameter of all steel strands. The segmented protective cover can effectively seal the anchor while reducing the structural size, reducing the amount of anti-corrosion medium injection, and reducing costs. Grouting holes and exhaust holes are also provided on the protective cover 1 to facilitate the injection of anti-corrosion medium. Furthermore, the larger end of the protective cover 1 is connected to the anchor plate 4 by a plurality of connecting screws 7, and a sealing ring 8 is provided between the protective cover 1 and the anchor plate 4 to ensure the sealing inside the protective cover 1.

[0056] See also Figure 1-3 6-12, a construction method of a grouting type non-bonded prestressed system of the present invention comprises the above-mentioned grouting type non-bonded prestressed system, and the method comprises the following steps:

[0057] S1, after the anchor plate 4 and the prestressed pipe are installed according to the design drawings, concrete is poured around the anchor plate 4 and the prestressed pipe to fix them;

[0058] S2, inserting the unbonded reinforcement 6 into the anchor plate 4 and the prestressed hole;

[0059] S3, after the concrete strength reaches the tensioning condition, the unbonded reinforcement positioning and grouting sealing structure is installed at the end of the anchor plate 4, and the prestressed duct is grouted;

[0060] S4. After the slurry strength in the prestressed duct reaches the design strength, the unbonded reinforcement positioning and grouting sealing structure is removed, and the PE sleeve of the exposed unbonded reinforcement 6 is peeled off;

[0061] S5, installing the anchor plate 2, the clip 3, and the tensioning machine, tensioning the steel strand without the bonding reinforcement 6, removing the tensioning machine after the tensioning is completed, and cutting off the excess steel strand to retain a certain length;

[0062] S6. Install the protective cover 1 and pour the soluble anti-corrosion medium 9 into the protective cover 1. At this time, the soluble anti-corrosion medium 9 fills the protective cover 1 and enters into the through groove 202 from the gaps and flow holes 203 corresponding to the outer peripheral surface of the anchor plate 2, and then enters into the space between the anchor plate 2 and the anchor pad 4, so that the anti-corrosion medium is quickly and evenly distributed in every corner of the anchor, providing long-term and effective anti-corrosion.

[0063] It should be noted that in the vertical prestressed tendon, the hole is relatively high and requires a relatively high grouting pressure. In this case, the grouting connector 5 can be used for grouting. Figure 1As shown, the grouting connector 5 is installed at the other end of the anchor plate 4, and the unbonded reinforcement 6 passes through the grouting connector 5, so that grouting can be performed through the grouting opening of the grouting connector 5.

[0064] The prestressed system construction method of the present invention can firstly thread the prestressed channel, grout and then tension it, adjust the inherent construction sequence of the non-bonded prestressed system, and improve the construction efficiency under specific working conditions.

[0065] Preferably, the above-mentioned non-bonded rib positioning and grouting sealing structure includes a sealing plate 10 and a pressure plate 11, wherein the pressure plate 11 is provided with a plurality of through holes 12, the same number as the non-bonded ribs 6, and a plurality of sealing plugs 13, the same number as the non-bonded ribs 6, are detachably installed on one side of the pressure plate 11, the positions of the plurality of sealing plugs 13 are arranged in one-to-one correspondence with the positions of the plurality of through holes 12, and the sealing plugs 13 are hollow structures for passing the non-bonded ribs 6, and the sealing plugs 13 that independently seal a single non-bonded rib 6 can be individually replaced if damaged during repeated use, thereby saving costs. The sealing plate 10 is provided with a plurality of tapered holes 14 having the same number as the non-bonded ribs 6, and the largest end of the tapered holes 14 is arranged toward the side of the sealing plug 13. The pressing plate 11 and the sealing plate 10 are detachably connected, which is convenient for disassembly and maintenance. When the pressing plate 11 and the sealing plate 10 are connected, the center lines of the plurality of sealing plugs 13, the tapered holes 14, and the through holes 12 coincide with each other one by one, ensuring that the non-bonded ribs 6 can pass through the sealing plate 10, the pressing plate 11, and the sealing plug 13. Specifically, during the connection process between the pressing plate 11 and the sealing plate 10, as the pressing plate 11 moves axially toward the sealing plate 10, the sealing plug 13 deforms radially toward the non-bonded ribs 6, and the axial deformation is converted into radial deformation through the tapered holes 14, so as to achieve sealing with the non-bonded ribs 6, and the sealing reliability is high.

[0066] The sealing structure of the present invention, by setting sealing units equal to the number of unbonded ribs, the sealing units are changed from a whole rubber plate to the cooperation of several sealing plugs and tapered holes, so as to realize independent sealing of a single unbonded rib, with less deformation, more uniform deformation, better sealing effect, and the ability to withstand higher grouting pressure without leakage. The tapered hole direction is automatically aligned, which can effectively improve the positioning accuracy of the unbonded ribs and the sealing effect during grouting.

[0067] Preferably, a sealing ring 8 is provided on the side of the sealing plate 10 away from the pressure plate 11. Specifically, a groove is opened on the sealing plate 10, and the sealing ring 8 is embedded in the groove to fix the sealing ring 8 and the sealing plate 10 together. The setting of the sealing ring 8 can further improve the sealing effect.

[0068] Preferably, each sealing plug 13 is provided with a tapered surface 132 that narrows inwardly at one end facing the tapered hole 14. The sealing plug 13 uses the tapered surface 132 to cooperate with the tapered hole 14 of the sealing plate 10, which can make the sealing plug 13 easier to deform, reduce the wear of the sealing plug 13, and extend its service life.

[0069] Preferably, a plurality of positioning screws 15 are further provided on the pressing plate 11, and the plurality of positioning screws 15 are all threadedly connected to the pressing plate 11 and the sealing plate 10. By providing the positioning screws 15 between the pressing plate 11 and the sealing plate 10, the relative deflection problem between the two can be prevented during the assembly process of the sealing structure, and the positioning screws 15 can also play a guiding role during the process of adjusting the axial movement of the pressing plate 11.

[0070] Preferably, a plurality of bolt holes 22 are provided on the sealing plate 10, and the positions of the plurality of bolt holes 22 correspond to the hole positions of the anchor plate 4, so that the entire sealing structure can be fixedly mounted on the anchor plate 4 by bolts. After the sealing structure is mounted on the anchor plate 4, the prestressed duct can be grouted.

[0071] Preferably, a pair of handles 18 are provided on the sealing plate 10 to facilitate the staff to operate the disassembly and assembly of the sealing structure.

[0072] Preferably, each sealing plug 13 is provided with a step 131 having a diameter greater than that of the sealing plug 13 at one end close to the pressing plate 11, and a recessed groove matching the step 131 is provided on the pressing plate 11 corresponding to the outer edge of each through hole 12. A fixing plate 20 is installed on one side of the pressing plate 11 through a fastening screw 19, and the fastening screw 19 is a countersunk screw. A plurality of through holes having the same number and outer diameter as the sealing plug 13 are provided on the fixing plate 20. When the fixing plate 20 is installed on the pressing plate 11, the step 131 is inserted into the recessed groove, and the sealing plugs 13 are inserted into the through holes. The fixing plate 20 presses the step 131 into the recessed groove, so as to realize the detachable installation of the sealing plug 13. In this embodiment, the positioning screw 15 and the top loosening screw 16 all pass through the fixing plate 20. In this embodiment, the sealing plug 13 and the pressing plate 11 are installed as one through the recessed groove and the fixing plate 20, so as to facilitate the installation and disassembly of the entire sealing structure.

[0073] Preferably, a connection component that can connect and lock or loosen and separate the two is provided between the pressure plate 11 and the sealing plate 10. The connection component of this embodiment includes a clamping screw 23 and a loosening screw 16, wherein a plurality of clamping screws 23 are provided on the pressure plate 11, and the plurality of clamping screws 23 are all threaded through the pressure plate 11 and the sealing plate 10, and the pressure plate 11 and the sealing plug 13 can be driven to move to one side of the sealing plate 11 by screwing the clamping screw 23, so as to tighten the sealing plug 13. In this embodiment, the clamping screw 23 passes through the fixed plate 20. A loosening screw 16 is also threadedly connected to the pressure plate 11, and the loosening screw 16 passes through the pressure plate 11. When disassembling the sealing structure, the sealing plate 10 can be pushed back by screwing the loosening screw 16, so that the pressure plate 11 and the sealing plug 13 can be pushed out of the sealing plate 10, thereby facilitating the disassembly of the sealing structure.

[0074] In the above step S3, when installing the non-bonded rib positioning and grouting sealing structure, the non-bonded rib positioning and grouting sealing structure is first assembled into a whole, and then installed at the end of the anchor pad 4. The assembly of the non-bonded rib positioning and grouting sealing structure includes the following steps:

[0075] a. Install all the steps 131 of the sealing plug 13 into the sink of the pressure plate 11, install the fixing plate 20, fix the fixing plate 20 to the pressure plate 11, and fix the sealing plug 13 to the pressure plate 11 as one;

[0076] b. Install the installed pressure plate 11 into the sealing plate 10, tighten the positioning screws 15 and the connecting components, and install the handle 18;

[0077] c. Evenly spread an isolation film on one end of the sealing plate 10 away from the pressure plate 11, and the isolation film may be a plastic wrap;

[0078] d. Install the sealing ring 8 into the sealing groove of the sealing plate 10 to obtain an integral non-bonded rib positioning and grouting sealing structure.

[0079] like Fig. 9 As shown, in one embodiment, a loosening assembly is provided on the sealing plate 10 for loosening the sealing plate 10. In this embodiment, the loosening assembly is a loosening nut 17. The loosening nut 17 is also threadedly connected to the periphery of the sealing plate 10. When disassembling the sealing structure, the loosening nut 17 can be twisted to loosen the anchor plate 4, so that the sealing structure can be loosened and separated from the anchor plate 4, which can facilitate the disassembly of the sealing structure. Preferably, a positioning groove can be provided on the outer wall of the loosening nut 17, so that the loosening nut 17 can be inserted into the positioning groove to rotate the loosening nut 17, which is more convenient to operate. In other embodiments, the loosening assembly can be a loosening screw, and the loosening screw 16 is threadedly connected to the sealing plate 10 to achieve the same effect.

[0080] like Fig.10As shown, in other embodiments, the connection assembly includes a locking nut 25, the threads at both ends of the locking nut 25 are in opposite directions, a connecting column 24 is provided on the side of the sealing plate 10 close to the pressing plate 11, the outer wall of the pressing plate 11 and the outer wall of the connecting column 24 are both provided with external threads, and the threads of the two are in opposite directions, and the two ends of the locking nut 25 are respectively threadedly connected to the pressing plate 11 and the connecting column 24, and the pressing plate 11 and the connecting column 24 are moved closer or farther apart by twisting the locking nut 25, so that the connection between the pressing plate 11 and the sealing plate 10 can be locked or loosened, and the sealing plate 10 and the pressing plate 11 are connected and loosened by the locking nut 25, so that the force of the two is more uniform, and their service life can be extended. Preferably, the outer wall of the locking nut 25 can be provided with a clamping groove, which is convenient for inserting a steel rod into the clamping groove to rotate the locking nut 25, and the operation is more convenient.

[0081] See also Figure 14-15 In other embodiments, the connecting assembly includes a locking nut 25, a connecting column 24 is provided on the side of the sealing plate 10 close to the pressure plate 11, one end of the locking nut 25 is rotatably sleeved on the connecting column 24, and a limiting structure for limiting the axial movement of the locking nut 25 is provided between the locking nut 25 and the connecting column 24. The limiting structure can be an annular limiting groove 26 opened on the outer wall of the connecting column 24 and a limiting ring 27 arranged at one end of the locking nut 25. The limiting ring 27 is sleeved in the limiting ring groove 26 so that the locking nut 25 can only rotate relative to the sealing plate 10 but cannot move axially relative to the sealing plate 10. The outer wall of the pressure plate 11 is provided with an external thread, and the other end of the locking nut 25 is threadedly connected to the pressure plate 11. In this way, by screwing the locking nut 25, the axial movement of the pressure plate 11 relative to the sealing plate 10 can also be achieved. In other embodiments, the limiting structure may be a limiting protrusion arranged on the outer wall of the connecting column 24 and a limiting ring 27 arranged at one end of the locking nut 25, or a limiting protrusion arranged on the outer wall of the connecting column 24 and a limiting groove opened on the inner wall at one end of the locking nut 25, which can achieve the same technical effect.

[0082] See also Figure 4-5 13. A method for tensioning a grouting type non-bonded prestressed system of the present invention comprises the above-mentioned grouting type non-bonded prestressed system, wherein the above-mentioned mounting structure is an external thread arranged on the outer peripheral surface of the anchor plate 2, and the pressure-bearing member is a support nut 21. The method comprises the following steps:

[0083] S1, remove the protective cover 1, and install the support nut 21 on the anchor plate 2;

[0084] S2, install the tensioning machine to supplement the steel strands of the exposed unbonded tendons 6. When the tensioning machine tensions the steel strands to a specified force value, the anchor plate 2 will be separated from the end surface of the anchor pad 4, and the support nut 21 will be screwed and fitted to the end surface of the anchor pad 4;

[0085] S4, dismantle the tensioning equipment, at which time the support nut 21 will support the anchor plate 2 and maintain the prestress;

[0086] S5. Install the protective cover 1 on the supporting nut 21 and inject the soluble anti-corrosion medium 9.

[0087] The prestressing system tensioning method of the present invention can be used to tension the prestress after several years of operation or when the prestress relaxation fails to meet the working condition requirements, thereby supplementing the structural prestress and improving the structural durability.

[0088] Preferably, a sealing ring 8 is installed at one end of the support nut 21 to ensure the sealing between the support nut 21 and the anchor plate 4, and a connecting ring 211 is provided at the other end of the support nut 21. The connecting ring 211 is provided with a plurality of connecting holes 212. The positions of the plurality of connecting holes 212 correspond one-to-one to the hole positions of the anchor plate 4 and are used to install the protective cover 1. This can achieve the need to replace the protective cover after re-stitching, thereby reducing the re-stitching cost.

[0089] In other embodiments, the above-mentioned mounting structure can also be a plurality of pin holes or threaded holes opened on the outer peripheral surface of the anchor plate 2, and the plurality of pin holes or threaded holes are distributed along the axial direction of the anchor plate 2. The pressure-bearing part is a support sleeve. After the tension is replenished, the pin passes through the support sleeve and is inserted into the pin hole, or the screw passes through the support sleeve and is threadedly connected in the threaded hole, so that the support sleeve supports the anchor plate 2 and maintains the prestress.

[0090] The above are only preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the structure of the present invention, which will not affect the effect of the implementation of the present invention and the practicality of the patent.

Claims

1. A grouting type non-bonded prestressed system, comprising a protective cover (1), an anchor plate (2), a clip (3), an anchor plate (4) and non-bonded tendons (6), wherein the protective cover (1) is mounted on one end of the anchor plate (4), the anchor plate (2) is located in the protective cover (1), the non-bonded tendons (6) penetrate the anchor plate (4) and the anchor plate (2) and extend into the protective cover (1), and the steel strands of the non-bonded tendons (6) are connected and fixed to the anchor plate (2) through the clip (3), characterized in that: A sinking platform (201) is provided on one side of the anchor plate (2) close to the anchor pad (4); a plurality of through grooves (202) radially penetrating to the outer peripheral surface of the anchor plate (2) are provided on the anchor plate (2) outside the sinking platform (201); each of the through grooves (202) is connected to a flow hole (203); the flow hole (203) penetrates to the other side of the anchor plate (2); the other side surface and the outer peripheral surface of the anchor plate (2) have a gap with the inner wall of the protective cover (1); and a mounting structure for mounting a pressure-bearing member during tensioning is provided on the anchor plate (2).

2. A grouting type unbonded prestressed system according to claim 1, characterized in that: The protective cover (1) is a stepped structure, and the anchor plate (2) is located inside the larger end of the protective cover (1).

3. A grouting type non-bonded prestressed system according to claim 2, characterized in that: The larger end of the protective cover (1) is connected to the anchor plate (4) via a plurality of connecting screws (7), and a sealing ring (8) is provided between the protective cover (1) and the anchor plate (4).

4. A grouting type non-bonded prestressed system construction method, characterized in that: A grouting type unbonded prestressed system according to claim 1, 2 or 3, the method comprising the following steps: S1, after the anchor plate (4) and the prestressed pipe are installed according to the design drawings, concrete is poured; S2, inserting the unbonded tendons (6) into the anchor plate (4) and the prestressed hole; S3, after the concrete strength reaches the tensioning condition, the unbonded reinforcement positioning and grouting sealing structure is installed at the end of the anchor pad (4), and the prestressed duct is grouted; S4. After the slurry strength in the prestressed duct reaches the design strength, the unbonded reinforcement positioning and grouting sealing structure is removed, and the PE sleeve of the exposed unbonded reinforcement (6) is peeled off; S5, installing the anchor plate (2), the clamp (3), and the tensioning machine, tensioning the steel strand without the bonding tendon (6), removing the tensioning machine after the tensioning is completed, and cutting off the excess steel strand to retain a certain length; S6. Install the protective cover (1) and inject a soluble anti-corrosion medium (9) into the protective cover (1).

5. A grouting type non-bonded prestressed system construction method according to claim 4, characterized in that: The non-bonded rib positioning and grouting sealing structure comprises a sealing plate (10) and a pressing plate (11); the pressing plate (11) is provided with a plurality of through holes (12) the same number as the non-bonded ribs (6), and one side of the pressing plate (11) is detachably mounted with a plurality of sealing plugs (13) the same number as the non-bonded ribs (6); the sealing plate (10) is provided with a plurality of conical holes (14) the same number as the non-bonded ribs (6), and the largest end of the conical hole (14) is arranged toward the side of the sealing plug (13); the pressing plate (11) and the sealing plate (10) are detachably connected, and when the pressing plate (11) and the sealing plate (10) are connected, the center lines of the plurality of sealing plugs (13), the conical holes (14) and the through holes (12) coincide with each other one by one, and a sealing ring (8) is provided on the side of the sealing plate (10) away from the pressing plate (11).

6. A grouting type non-bonded prestressed system construction method according to claim 5, characterized in that: The pressing plate (11) is also provided with a plurality of positioning screws (15), and the plurality of positioning screws (15) all penetrate the pressing plate (11) and are threadedly connected to the sealing plate (10).

7. A grouting type non-bonded prestressed system construction method according to claim 5, characterized in that: The sealing plate (10) is provided with a loosening component capable of loosening the sealing plate, and a connecting component capable of connecting and locking the two or loosening and separating the two is provided between the pressing plate (11) and the sealing plate (10).

8. A grouting type non-bonded prestressed system construction method according to claim 5, characterized in that: Each of the sealing plugs (13) is provided with a step (131) having a diameter greater than that of the sealing plug (13) at one end close to the pressure plate (11); a recessed groove matching the step (131) is provided on the pressure plate (11) corresponding to the outer edge of each through hole (12); a fixing plate (20) is installed on one side of the pressure plate (11) by means of a fastening screw (19); the fixing plate (20) is provided with a plurality of through holes having the same number and outer diameter as the sealing plugs (13); when the fixing plate (20) is installed on the pressure plate (11), the fixing plate (20) presses the step (131) tightly into the recessed groove.

9. A grouting type non-bonded prestressed system tensioning method, characterized in that: The method comprises a grouting type unbonded prestressed system as claimed in claim 1, 2 or 3, wherein the mounting structure is an external thread arranged on the outer peripheral surface of the anchor plate (2), and the pressure bearing member is a support nut (21). The method comprises the following steps: S1. Remove the protective cover (1) and install the support nut (21) on the anchor plate (2); S2. Install a tensioning machine to re-tension the steel strands of the exposed unbonded tendons (6). When the tensioning machine tensions the steel strands to a specified force value, the anchor plate (2) will separate from the end face of the anchor pad (4), and the support nut (21) will be screwed and attached to the end face of the anchor pad (4); S4, dismantle the tensioning equipment, at which time the support nut (21) will support the anchor plate (2) and maintain the prestress; S5. Install the protective cover (1) on the supporting nut (21) and inject a soluble anti-corrosion medium (9).

10. A grouting type non-bonded prestressed system tensioning method according to claim 9, characterized in that: A sealing ring (8) is installed at one end of the support nut (21), and a connecting ring (211) is provided at the other end of the support nut (21). The connecting ring (211) is provided with a plurality of connecting holes (212), and the positions of the plurality of connecting holes (212) correspond one-to-one to the hole positions of the anchor plate (4).

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