Reinforced concrete beam external prestressed reinforcement structure and method of npr steel bar

Abstract

The application provides a reinforced concrete beam external prestressed reinforcement structure of NPR steel bars, which comprises NPR steel bars, anchoring structures and prestress applying assemblies for tensioning the NPR steel bars; the prestress applying assemblies comprise steel bar prestress applying anchorage devices, through-tensioning jacks, guide rods, temporary fixing assemblies and anchor plate assemblies; the temporary fixing assemblies comprise clamping plate clamps which can be clamped and fixed on both sides of the reinforced concrete beam structure and mounting seats arranged below the clamping plate clamps; the reinforcement structure of the application can overcome the large deformation problem under dynamic load while achieving reinforcement of the prestressed reinforced concrete beam by optimizing the prestressed material, and the structure is simple and convenient to install; the method of the application uses the aforementioned reinforced concrete beam external prestressed reinforcement structure, and no hole is punched on the concrete beam structure when the tensioning jack is temporarily fixed, so that the secondary damage to the reinforced concrete beam structure during external prestressed reinforcement can be reduced.

Description

Technical Field

[0001] This invention belongs to the field of concrete and beam external prestressing reinforcement technology, specifically relating to an external prestressing reinforcement structure and method for reinforced concrete beams with NPR steel bars. Background Technology

[0002] Reinforced concrete beams are one of the main load-bearing components in building structures. Reinforced concrete beams may suffer structural damage under the influence of earthquakes, ground subsidence, or other external forces, resulting in a decrease in their load-bearing capacity, thus requiring reinforcement.

[0003] Currently, external prestressing reinforcement is the main method used, and many technologies exist for this type of structure. For example, the invention patent for external prestressing reinforcement structure and method for concrete T-beams (CN105926468B) uses high-strength aluminum alloy to improve the load-bearing capacity and durability of the concrete T-beam. The two ends of the prestressed steel bars are the anchoring end and the tensioning end, respectively. Tensioning is achieved at the tensioning end using a through-hole jack, and the tensioning stress is controlled by a digital display, causing the steel bars to undergo tensile strain and establish prestress. However, the installation of external prestressed steel bars inevitably requires openings in the concrete beam for anchoring. Before tensioning with the through-hole jack, openings are also typically made in the concrete beam to fix the jacks with bases. Repeated openings further damage the concrete beam. Therefore, how to minimize external prestressing reinforcement while reducing secondary damage to the reinforced concrete beam structure is a pressing issue that needs to be addressed.

[0004] Meanwhile, as the most common type of prestressed steel bar, precision-rolled threaded steel bars PSB830 and PSB930 have an ultimate elongation of less than 20%, and their strength will decrease when the elongation reaches 10-15%. Traditional reinforcement materials cannot simultaneously meet the requirements of high ductility and high tensile strength. Reinforced concrete beams reinforced with traditional reinforcement materials cannot withstand the large deformation and damage caused by the impact of severe dynamic loads, such as earthquakes, explosions, and penetration. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide an external prestressed reinforcement structure and method for reinforced concrete beams with NPR steel bars.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] An external prestressed reinforcement structure for reinforced concrete beams with NPR steel bars includes NPR steel bars, anchorage structures anchored at both ends of the length of the reinforced concrete beam structure to be reinforced, and a prestressing application assembly for tensioning the NPR steel bars; the two ends of the NPR steel bars are a fixed end and a tensioning end, respectively; the NPR steel bars reach the target prestress after being pulled by the prestressing application device, and the two ends of the NPR steel bars with the target prestress are respectively fixed to the two anchorage structures.

[0008] The prestressing application assembly includes a steel prestressing anchor, a through-type tensioning jack, a guide rod inserted inside the tensioning jack, a temporary fixing assembly for temporarily fixing the guide rod on the reinforced concrete beam structure to be reinforced, and an anchor plate assembly for transmitting the tensioning force of the tensioning jack to the steel prestressing anchor.

[0009] The temporary fixation assembly includes clamping plates that can be clamped and fixed to both sides of the reinforced concrete beam structure and a mounting base disposed below the clamping plates; the upper part of the anchor plate assembly is detachably fixed to the NPR rebar and close to the tensioning end; the guide rod is parallel to the length direction of the reinforced concrete beam structure, and one end of the guide rod is detachably fixed to the temporary fixation assembly, and the other end of the guide rod is detachably fixed to the mounting base; the tensioning jack is disposed between the mounting base and the anchor plate assembly, and the traction end of the tensioning jack is provided with an axial force sensor that abuts against the anchor plate assembly; the NPR rebar passes through the clamping plates and the mounting base, and the rebar prestressing anchor is fixed to the NPR rebar and located between the anchor plate assembly and the tensioning end of the NPR rebar.

[0010] Furthermore, the NPR rebar thread is a six-ribbed thread with ribs and interrib grooves on the surface; the anchoring structure includes anchor bolts, T-shaped steel, and rebar clamps; the NPR rebar is fixed to the T-shaped steel by the rebar clamps;

[0011] The T-shaped steel is fixed to the reinforced concrete beam structure by anchor bolts. Anchor grooves are provided on the T-shaped steel. A set of steel bar wedges is matched in each anchor groove. Each set of steel bar wedges consists of three wedges. The inner side of each steel bar wedge is provided with wedge protrusions that engage with the interrib grooves of the NPR steel bar. The overall shape of a set of steel bar wedges is frustoconical, and the larger end of each steel bar wedge faces the nearest end of the reinforced concrete beam structure.

[0012] Furthermore, the anchor plate assembly includes two sets of anchor plates, two anchor plate rods, two sets of anchor plates passing through the anchor plate rods, and fasteners threaded to the upper and lower ends of the anchor plate rods and pressed against the outer surface of the anchor plates. Each set of anchor plates has a clamping groove in its center. The NPR steel bar is clamped in the upper clamping groove, and the guide rod is clamped in the lower clamping groove.

[0013] Furthermore, an adjustable pad with adjustable thickness is provided between the two sets of anchor plates.

[0014] Furthermore, the clamping fixture includes a clamping base plate, a clamping fixed block, a clamping movable block, and a movable clamping device. The clamping fixed block is fixedly disposed at one end of the upper surface of the clamping base plate. The clamping movable block is slidably connected to the upper surface of the clamping base plate and cannot be dislodged from the clamping base plate from above. The movable clamping device is connected to the clamping movable block and drives the clamping movable block to move to adjust the distance between the clamping fixed block and the clamping movable block. The clamping base plate is provided with a plurality of clamping lifting rods, and the mounting base is installed on the lower part of the clamping lifting rods by fasteners.

[0015] Furthermore, several protrusions are provided on the opposing surfaces of the fixed block and the moving block of the clamp.

[0016] Furthermore, one of the aforementioned fastening components may include one or more independent clamping plates, with the same mounting base corresponding to the lower part of all the clamping plates.

[0017] Furthermore, a clamping block is provided on the clamping base plate, and a plate hole is opened in the middle of the clamping block. The movable clamping device is connected to the clamping block, and the moving end of the movable clamping device passes through the plate hole and is connected to the movable clamping block. The movable clamping device is a clamping extrusion bolt or an extrusion jack.

[0018] Furthermore, the surface of the NPR steel bar is coated with an epoxy resin, and the anchoring structure and the NPR steel bar are covered with a concrete protective layer.

[0019] This invention also proposes a method for external prestressing reinforcement of reinforced concrete beams with NPR steel bars. Using the aforementioned external prestressing reinforcement structure for NPR steel bars, the method includes the following steps:

[0020] Step 1: Based on the structural requirements and known load magnitude, design the NPR steel external prestressing reinforcement for the reinforced concrete beam structure that needs to be strengthened, and determine the amount of NPR steel and the magnitude of prestress.

[0021] Step 2: Cut and fabricate NPR steel bars and anchorage structures;

[0022] Step 3: Apply epoxy resin coating to the required NPR steel bars and matching metal materials;

[0023] Step 4: Position and anchor the fixed end of the NPR steel bar, and anchor the fixed end of the NPR steel bar to one end of the reinforced concrete beam structure to be reinforced through the anchoring structure.

[0024] Step 5: Fix the anchoring structure corresponding to the tensioning end to the other end of the reinforced concrete beam structure that needs to be reinforced. The NPR steel bar passes through the anchoring structure but is not fixed to it for the time being.

[0025] Step 6: Install the clamping plates and fixtures in appropriate positions and fix them to the reinforced concrete beams that need to be reinforced.

[0026] Step 7: Install the mounting base under the clamping fixture;

[0027] Step 8: Connect one end of the guide rod to the mounting base;

[0028] Step 9: Install the tensioning jack and axial force sensor on the guide rod;

[0029] Step 10: Install the anchor plate assembly that matches the NPR rebar to connect the NPR rebar to the guide rod;

[0030] Step 11: Tension the NPR prestressed steel bars with jacks, and use axial force sensors to monitor the applied prestress in real time. Stop tensioning when the design prestress is reached. After tensioning, anchor the tensioned end of the NPR steel bars to the anchoring structure.

[0031] Step 12: Remove the guide rod, temporary fixing assembly, and anchor plate assembly;

[0032] Step 13: Pour the concrete protective layer.

[0033] The beneficial effects of this invention are:

[0034] The reinforcement structure of this invention makes full use of the original building and bridge structures, improving the service life and utilization rate of buildings, reducing maintenance costs and making maintenance easier; by optimizing the prestressed materials, it can ensure that the prestressed reinforced concrete beam can overcome the problem of large deformation under dynamic loads while achieving reinforcement; the structure of this invention is simple, easy to install, and adopts a non-drilling installation method, avoiding structural damage to the concrete beam structure.

[0035] The method of the present invention improves the prestressing application component by eliminating the need to drill holes in the concrete beam structure when temporarily fixing the tensioning jack, thereby reducing secondary damage to the reinforced concrete beam structure during external prestressing reinforcement. Attached Figure Description

[0036] The attached drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation to the present invention. Among them:

[0037] Figure 1 is the static tensile curve of the NPR steel bars used in the present invention and traditional steel bars;

[0038] Figure 2 is the schematic diagram of the surface structure of the NPR steel bars used in the present invention;

[0039] Figure 3 is the schematic diagram of the external prestressing reinforcement structure of the NPR steel bars in the embodiment of the present invention;

[0040] Figure 4 is the schematic diagram of the structure of the prestressing application device for NPR steel bars in an embodiment of the present invention;

[0041] Figure 5 is the schematic diagram of the installation structure of the matching anchor plate assembly for NPR steel bars in the embodiment of the present invention;

[0042] Figure 6 The front view of the structure of the prestressing application fixture in the embodiment of the present invention;

[0043] Figure 7 is the top view of the structure of the prestressing application fixture in the embodiment of the present invention;

[0044] Figure 8 is the schematic diagram of the matching T-shaped steel structure for NPR steel bars in the embodiment of the present invention;

[0045] Figure 9 is the schematic diagram of the structure of the steel bar wedge for NPR steel bars in the embodiment of the present invention;

[0046] Figure 10 The schematic diagram of the structure of the mounting seat in the embodiment of the present invention;

[0047] Figure 11 is the schematic diagram of the structure of the mounting seat in another embodiment of the present invention.

[0048] In the diagram, 1-NPR rebar, 101-rib groove, 2-HRB400E rebar, 3-PSB830 rebar, 4-PSB930 rebar, 5-reinforced concrete beam structure, 6-epoxy resin coating, 7-T-section steel, 701-steel positioning through hole, 8-stiffening rib, 9-anchor groove, 10-rebar wedge, 111-wedge protruding rib, 11-anchor plate, 12-guide rod, 13-adjusting pad, 14-first pressure nut, 15-anchor plate hanger, 16-rebar 17-Prestressing application anchor, 18-Tensioning jack, 19-Anchor bolt, 20-Concrete protective layer, 21-Axial force sensor, 22-Protrusion, 23-Clamp positioning through hole, 24-Clamp compression bolt, 25-Moving block slide, 26-Clamp stationary block, 27-Clamp moving block, 28-Seat positioning through hole, 29-Guide rod through hole, 30-Mounting seat, 31-Second pressure nut, 32-Clamp hanging rod, 33-Clamp upright block, 34-Bar prestressing application anchor. Detailed Implementation

[0049] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art are within the scope of protection of the present invention.

[0050] In the description of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and do not require the invention to be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. The terms "connected" and "linked" used in this invention should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; they can refer to a direct connection or an indirect connection through intermediate components. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0051] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0052] like Figures 2 to 11As shown, an external prestressed reinforcement structure for a reinforced concrete beam with NPR steel bars 1 includes NPR steel bars 1, anchorage structures anchored at both ends of the length of the reinforced concrete beam structure 5 to be reinforced, and a prestressing application assembly for tensioning the NPR steel bars 1. The two ends of the NPR steel bars 1 are a fixed end and a tensioning end, respectively. After being pulled by the prestressing application device, the NPR steel bars 1 reach the target prestress. The two ends of the NPR steel bars 1 with the target prestress are fixed to the two anchorage structures respectively. The fixed end anchorage structure and the tensioning end anchorage structure should be as close as possible to the two ends of the beam to better utilize the prestress of the NPR steel bars 1.

[0053] The prestressing application assembly includes a steel prestressing application anchor 16, a through-type tensioning jack 17, a guide rod 12 inserted in the tensioning jack 17, a temporary fixing assembly for temporarily fixing the guide rod 12 on the reinforced concrete beam structure 5 to be reinforced, and an anchor plate assembly for transmitting the tension force of the tensioning jack 17 to the steel prestressing application anchor 16.

[0054] The temporary fixation assembly includes clamping plates that can be clamped and fixed on both sides of the reinforced concrete beam structure 5 and a mounting base 30 located below the clamping plates. In use, the clamping plates are fixed on the reinforced concrete beam to be reinforced, and the mounting base 30 provides positioning and support for the tensioning jack 17. The upper part of the anchor plate assembly is detachably fixed to the NPR steel bar 1 and close to the tensioning end. The guide rod 12 is parallel to the length direction of the reinforced concrete beam structure 5, and one end of the guide rod 12 is detachably fixed to the temporary fixation assembly, and the other end of the guide rod 12 is detachably fixed to the mounting base 30. The tensioning jack 17 is located between the mounting base 30 and the anchor plate assembly, and the traction end of the tensioning jack 17 is provided with an axial force sensor 20 that abuts against the anchor plate assembly. The NPR steel bar 1 passes through the clamping plates and the mounting base 30, and the steel bar prestressing anchor 16 is fixed to the NPR steel bar 1 and located between the anchor plate assembly and the tensioning end of the NPR steel bar 1.

[0055] The NPR steel bar 1 used in this invention is the NPR steel bar 1 in patent CN110524192B. It is a steel bar with a yield strength of 800-950MPa, a tensile strength of 1000-1100MPa, and a maximum force elongation of ≥10-40%. It can better achieve pre-tightening force and has excellent dynamic characteristics such as impact and explosion resistance. Figure 1 The static tensile curves of NPR steel bar 1 and traditional steel bars represented by HRB400E steel bar 2, PSB830 steel bar 3, and PSB930 steel bar 4 are shown. As can be seen from the curves, NPR steel bar 1 has a higher elongation while maintaining higher tensile strength compared to traditional steel bars. This characteristic makes up for the shortcomings of traditional steel bars in that they cannot achieve both elongation and high tensile strength. Therefore, NPR steel bar 1 can provide more reliable and flexible performance to meet a variety of engineering needs.

[0056] The prestressing application component used in this invention does not use the conventional method of drilling holes in the concrete beam to install anchors for temporary fixation of the tensioning jack 17. Instead, it uses clamping plates and clamps to clamp the tensioning jack 17 on both sides of the reinforced concrete beam structure 5 for temporary fixation. This non-drilling installation method can avoid secondary damage to the reinforced concrete beam structure 5 to be reinforced during construction. This invention is applicable to reinforced concrete beam structures 5 with a width of 200-400mm.

[0057] like Figure 2 , Figure 3 , Figure 9 As shown, the NPR steel bar 1 has a six-ribbed thread with ribs and interrib grooves 101 on its surface; the anchoring structure includes anchor bolts 18, T-shaped steel 7, and steel bar wedges 10; the NPR steel bar 1 is fixed to the T-shaped steel 7 by the steel bar wedges 10; the T-shaped steel 7 consists of a horizontal plate, a vertical plate, and triangular stiffening ribs 8 welded between the horizontal and vertical plates, with the vertical plate vertically set on the horizontal plate; the horizontal plate of the T-shaped steel 7 has several steel positioning through holes 701, and the T-shaped steel 7 is fixed to the reinforced concrete beam structure 5 by anchor bolts 18 passing through the steel positioning through holes 701; the vertical plate of the T-shaped steel 7 has 2-3 through holes, and anchor grooves 9 are welded to the positions of the through holes, so that the prestress of the NPR steel bar 1 can be better transferred to the reinforced concrete beam member to be strengthened through the T-shaped steel 7;

[0058] A set of three steel bar clips 10 are matched within each anchor groove 9. A new type of steel bar clip 10 is designed for better anchoring of the NPR steel bar 1. The inner side of each steel bar clip 10 has clip protrusions 111 that engage with the interrib grooves 101 of the NPR steel bar 1, enabling better matching and reducing slippage during prestressing. Each set of steel bar clips 10 has an overall frustum shape, with the larger end of each clip facing the end of the nearest reinforced concrete beam structure 5. The steel bar clips 10 clamp the NPR steel bar 1 onto the T-shaped steel 7, coupling the NPR steel bar 1 with the reinforced reinforced concrete beam structure 5 after fixation. Due to the design of the steel bar clips 10 being thicker on the outside and thinner on the inside, after prestressing is applied to the NPR steel bar 1, the clips 10 tighten the two ends of the NPR steel bar 1 under the tension of the NPR steel bar 1. The anchoring structure of the fixed end and the tensioning end of the NPR steel bar 1 is the same. Figure 4 The image shows the tensioning end structure of NPR steel bar 1 during tensioning. At this time, the tensioning end of NPR steel bar 1 passes through the anchor groove 9, the steel bar wedge 10 has not yet been installed, and the tensioning end has not yet been anchored.

[0059] To facilitate the application of prestress to NPR steel bar 1, an anchor plate assembly structure matching NPR steel bar 1 is designed. For example... Figure 4 , Figure 5 , Figure 11 As shown, the anchor plate assembly includes two sets of anchor plates 11, two anchor plate hangers 15, two sets of anchor plates 11 passing through the anchor plate hangers 15, and fasteners threaded to the upper and lower ends of the anchor plate hangers 15 and pressed against the outer surface of the anchor plates 11. An adjustable shim 13 is provided between the two sets of anchor plates 11. The shim 13 has different thicknesses, with a central perforation or a U-shape. Different thicknesses of the shim 13 can be selected according to the position of the guide rod 12, ensuring that the guide rod 12 and the NPR rebar 1 remain horizontal. Each set of anchor plates 11 has a central groove, meaning each anchor plate 11 has a groove on the opposite side of the same set of anchor plates 11. The two grooves in each set are joined together to form a clamping groove. The NPR rebar 1 is clamped in the upper clamping groove, and the guide rod 12 is clamped in the lower clamping groove. In one embodiment, the two ends of the boom are provided with external threads, and the fastener is a first pressure nut 14, which is located on the upper side of the uppermost anchor plate 11 and the lower side of the lowermost anchor plate 11. The NPR steel bar 1 is fastened in the clamping groove by two sets of anchor plates 11, and the guide rod 12 is fastened in the clamping groove by two sets of anchor plates 11. The distance between the upper and lower parts is adjusted by adjusting the shim 13. Finally, by tightening the first pressure nut 14, the two sets of anchor plates 11 clamp the NPR steel bar 1 and the guide rod 12, so that the anchor plate assembly is fastened into a whole, and the NPR steel bar 1 and the guide rod 12 are subjected to force together, so that the NPR steel bar 1 and the guide rod 12 can be reliably and synchronously pulled when the tensioning jack 17 is activated, which facilitates the application of preload.

[0060] like Figure 4 , Figure 6 , Figure 7 , Figure 11As shown, the clamping fixture includes a clamping base plate 27, a clamping fixed block 25, a clamping movable block 26, a clamping upright block 33, and a movable clamping device. The clamping fixed block 25 and the clamping movable block 26 are respectively fixed to one end of the upper surface of the clamping base plate 27. The clamping movable block 26 is slidably connected to the upper surface of the clamping base plate 27 and cannot be removed from the clamping base plate 27 from above. A plate hole is opened in the middle of the clamping upright block 33. The movable clamping device is connected to the clamping upright block 33, and the moving end of the movable clamping device passes through the plate hole and is connected to the clamping movable block 26. The movable clamping device drives the clamping movable block 26 to move. The distance between the fixed block 25 and the movable block 26 of the clamp is adjusted by moving the clamp. Several clamp lifting rods 32 are provided on the clamp base plate 27. A ring of clamp positioning through holes 22 is formed along the outer edge of the clamp base plate 27. The mounting base 30 is an integral I-beam. The integral I-beam has vertically continuous mounting holes 28 corresponding to the positions of the clamp positioning through holes 22, and horizontally continuous guide rod through holes 29 for the guide rod 12 to pass through. In use, the clamp lifting rods 32 pass through the clamp positioning through holes 22 and the mounting base 30. 8. The fasteners are used to fix the position. The fasteners can be the second pressure nut 31, which is threaded onto the clamping rod 32. The second pressure nut 31 presses the clamping base plate 27 and the mounting seat 30 from above and below, fixing their positions on the clamping rod 32. Two rod prestressing anchors 34 are fixed on the guide rod 12. The opposite surfaces of the two rod prestressing anchors 34 abut against the mounting seat 30 and the anchor plate 11, respectively, so that the tensioning jack 17 and the axial force sensor 20 are clamped between the mounting seat 30 and the anchor plate 11. The guide rod 12 is fixed in the guide rod through hole 29 through a matching fastener; the clamping plate is made of high-speed tool steel, which has high hardness, high strength, and strong wear resistance, thus better realizing the integrity of the prestressed structure and the required reinforced concrete. The clamping plate should clamp the concrete beam structure as tightly as possible during use. The dimensions of the clamping block 25 and the clamping moving block 26, as well as the number of surface protruding anchors n, need to be adjusted according to the width of the required reinforced concrete beam and the required preload force F of the NPR reinforcement 1. By measuring the frictional force f1 of a single anchor and the frictional force f2 between the clamping block and the concrete contact surface, 2n f... 1+ 2f2>F, ensuring that the fixture and prestressing structure maintain their integrity during the prestressing process, and are able to withstand the vertical load (weight) of the prestressing structure and the lateral load brought by the prestress.

[0061] Specifically, such as Figure 7 As shown, a movable block slide 24 is provided on the upper surface of the fixture base plate 27, and a movable block slider that slides in the movable block slide 24 is protruding and fixed on the lower surface of the fixture movable block 26. The cross-section of the movable block slide 24 is an inverted T-shape, a dovetail shape, etc.

[0062] like Figure 6 , Figure 7As shown, several protrusions 21 are provided on the opposite surfaces of the clamp fixed block 25 and the clamp moving block 26. The protrusions 21 can be raised anchors. The protrusions 21 increase the friction and anchoring force between the clamp and the surface of the reinforced concrete beam, making it easier to fix them more reliably on the reinforced concrete beam to be reinforced. The protrusion height of the protrusions 21 should be controlled within 5mm to prevent serious damage to the surface of the reinforced concrete to be reinforced. The clamp fixed block 25 and the clamp moving block 26 should be equal in size and opposite surface area, and the minimum size should be greater than or equal to 5cm × 10cm.

[0063] like Figure 4 , Figure 11 As shown, a temporary fixing component may include one or more independent clamping plates, such as... Figure 11 As shown, all clamping plates and fixtures are provided with the same mounting base 30 below them, so that multiple clamping plates and fixtures provide clamping force to the mounting base 30.

[0064] like Figure 6 , Figure 7 As shown, in one embodiment, the movable clamping device is a clamping bolt 23, which is threaded into the plate hole and one end abuts against the clamping moving block 26. The clamping bolt 23 can slide and adjust on the clamping block slide. To apply force better, a bolt wrench through hole is reserved on the clamping bolt 23, which can increase the tightening force by wrench. In one embodiment, the movable clamping device is a clamping jack.

[0065] like Figure 3 As shown, the surface of the NPR steel bar 1 is coated with epoxy resin 6. The epoxy resin coating 6 reduces the corrosion caused by environmental impact and isolates the surface of the NPR steel bar 1 from the air environment. The prestress of the NPR steel bar 1 is applied by tensioning jack 17. After the required prestress of the NPR steel bar 1 is reached, the tensioning end of the NPR steel bar 1 is anchored. Then, the tensioning jack 17, temporary fixing components and components are removed. Finally, a concrete protective layer 19 is added. The concrete protective layer 19 completely covers the lower surface of the anchoring structure. After the clamping plates and fixtures are removed, if there is surface damage on both sides of the reinforced concrete beam structure 5, some concrete can be smoothed on the surface damage or the entire side of the reinforced concrete beam structure 5 while constructing the concrete protective layer 19 to maintain the aesthetic appearance of the reinforced concrete beam structure 5.

[0066] This invention also proposes a method for external prestressing reinforcement of reinforced concrete beams with NPR steel bars 1. Using the aforementioned external prestressing reinforcement structure for reinforced concrete beams with NPR steel bars 1, the method for external prestressing reinforcement of reinforced concrete beams with NPR steel bars 1 includes the following steps:

[0067] Step 1: According to the structural requirements and the known load magnitude, conduct an external prestressing reinforcement design for the reinforced concrete beam structure 5 to be strengthened, and determine the quantity of NPR steel bars 1 used and the prestress magnitude.

[0068] Step 2: Cut and fabricate the NPR steel bars 1, T-shaped steel 7, mounting seats 30, anchoring structures, etc.

[0069] Step 3: Apply an epoxy resin coating 6 to the required NPR steel bars 1 and supporting metal materials such as T-shaped steel 7.

[0070] Step 4: Position and anchor the fixed end of the NPR steel bar 1. Install the T-shaped steel 7 at one end of the reinforced concrete beam structure 5 to be strengthened by using anchor bolts 18 and the shaped steel positioning through holes 701; connect the NPR steel bar 1 with the fixed-end T-shaped steel 7, and use the steel bar clamping pieces 10 supporting the NPR steel bar 1 to connect with the anchor grooves 9 on the T-shaped steel 7. The clamping piece protrusion ribs 111 of the steel bar clamping pieces 10 are engaged with the rib grooves 101 on the surface of the NPR steel bar 1.

[0071] Step 5: Install the tension end T-shaped steel 7 at the other end of the reinforced concrete beam member to be strengthened by using the same positioning method. The NPR steel bar 1 passes through the slot holes of the anchoring structure T-shaped steel 7.

[0072] Step 6: Install a clamping plate fixture at an appropriate position near the tension end, and the clamping plate fixture is clamped and fixed on the reinforced concrete beam to be strengthened.

[0073] Step 7: Install the mounting seat 30 under the clamping plate fixture: Connect the mounting seat 30 with the overtime fixture into a whole through the fixture suspension rod 32 and the second pressure nut 31.

[0074] Step 8: Connect one end of the guide rod 12 to the mounting seat 30 through the rod prestress application anchor 34.

[0075] Step 9: Install a tension jack 17 and an axial force sensor 20 on the guide rod 12.

[0076] Step 10: Install the anchor plate assembly supporting the NPR steel bar 1. Use the anchor plate 11 and fasteners to fasten the NPR steel bar 1, the guide rod 12, and the adjusting pad 13 respectively, so as to connect the NPR steel bar 1 with the guide rod 12. Then use the rod prestress application anchor 34 to connect the other end of the guide rod 12 to the anchor plate assembly; as Figure 4 is the structural schematic diagram after the installation of the temporary fixing component and the anchor plate component is completed.

[0077] Step 11: Tension the NPR prestressed steel bars with jacks and use axial force sensor 20 to monitor the applied prestress in real time. Stop tensioning when the design prestress is reached. After tensioning, install steel bar clamps 10 to anchor the tensioned end of the NPR steel bar 1 in the anchor groove 9.

[0078] Step 12: Remove the guide rod 12, the temporary fixing assembly, and the anchor plate assembly;

[0079] Step 13: Pour the concrete protective layer 19, ultimately achieving the following appearance. Figure 3 The structure shown.

[0080] This invention makes full use of the existing building and bridge structures, improving the service life and utilization rate of buildings, reducing maintenance costs and making maintenance easier; when NPR steel bars 1, as external prestressing tendons, become loose during use, the prestressing tendons can be tensioned or replaced, effectively overcoming the problem of large deformation of buildings under dynamic disasters and ensuring the safety of people's lives and property when hazards occur; this invention has a simple structure, is easy to install, and adopts a non-drilling installation method, avoiding secondary damage to the required reinforced concrete beam structure 5 during construction.

[0081] It is understood that the above description is merely exemplary and the embodiments of this application are not intended to limit the scope of the invention. The above description is only a preferred embodiment of the present invention and is not intended to limit the invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are within the scope of protection of the pending claims of the present invention.

Claims

1. A structure for externally prestressing a reinforced concrete beam with NPR reinforcement, characterized in that: The application relates to a NPR steel bar (1), an anchoring structure anchored at both ends of a reinforced concrete beam structure (5) to be reinforced, and a prestress applying assembly for tensioning the NPR steel bar (1); the two ends of the NPR steel bar (1) are respectively fixed ends and tensioning ends, the NPR steel bar (1) reaches a target prestress after being pulled by the prestress applying device, and the two ends of the NPR steel bar (1) with the target prestress are respectively fixed on two anchoring structures; The prestress applying assembly comprises a steel bar prestress applying anchorage device (16), a through-tensioning jack (17), a guide rod (12) arranged in the through-tensioning jack (17), a temporary fixing assembly for temporarily fixing the guide rod (12) on the reinforced concrete beam structure (5) to be reinforced, and an anchor plate assembly for transmitting the pulling force of the through-tensioning jack (17) to the steel bar prestress applying anchorage device (16); The temporary fixing assembly comprises a clamping plate clamp which can be clamped and fixed on both sides of the reinforced concrete beam structure (5) and a mounting seat (30) arranged below the clamping plate clamp; the upper part of the anchor plate assembly can be detachably fixed on the NPR steel bar (1) and close to the tensioning end; the guide rod (12) is parallel to the length direction of the reinforced concrete beam structure (5), one end of the guide rod (12) can be detachably fixed on the temporary fixing assembly, and the other end of the guide rod (12) can be detachably fixed on the mounting seat (30); the through-tensioning jack (17) is arranged between the mounting seat (30) and the anchor plate assembly, and the pulling end of the through-tensioning jack (17) is provided with an axial force sensor (20) abutting against the anchor plate assembly; the NPR steel bar (1) passes through between the clamping plate clamp and the mounting seat (30), and the steel bar prestress applying anchorage device (16) is fixed on the NPR steel bar (1) and located between the anchor plate assembly and the tensioning end of the NPR steel bar (1); The clamping plate clamp comprises a clamp bottom plate (27), a clamp fixed block (25), a clamp movable block (26) and a movable clamping device; the clamp fixed block (25) is fixedly arranged at one end of the upper surface of the clamp bottom plate (27); the clamp movable block (26) is slidably connected to the upper surface of the clamp bottom plate (27) and cannot be taken out of the clamp bottom plate (27) from above; the movable clamping device is connected to the clamp movable block (26) and drives the clamp movable block (26) to move so as to adjust the spacing between the clamp fixed block (25) and the clamp movable block (26); a plurality of clamp hangers (32) are arranged on the clamp bottom plate (27), and the mounting seat (30) is mounted on the lower part of the clamp hangers (32) through fasteners; and the mounting seat (30) is an integrated I-shaped steel.

2. The reinforced concrete beam externally prestressed with NPR steel reinforcement according to claim 1, characterized in that: The NPR steel bar (1) is provided with six-rib type threads, ribs and rib-to-rib grooves (101) on the surface; the anchoring structure comprises an anchor bolt (18), a T-shaped steel (7) and a steel bar clamping piece (10); and the NPR steel bar (1) is fixed on the T-shaped steel (7) through the steel bar clamping piece (10). The T-shaped steel (7) is fixed on the reinforced concrete beam structure (5) through an anchor bolt (18), the T-shaped steel (7) is provided with an anchor slot (9), one anchor slot (9) is matched with a group of steel clamping pieces (10), each group of steel clamping pieces (10) is three, and the inner side of the steel clamping piece (10) is provided with a clamping piece protruding rib (111) which is engaged and matched with the rib interstitial groove (101) of the NPR steel bar (1); the shape of one group of the steel clamping piece (10) is a whole circular truncated cone, and the end of the steel clamping piece (10) with a larger size is directed to the end of the nearest reinforced concrete beam structure (5).

3. The externally prestressed reinforced concrete beam structure of NPR bars as claimed in claim 1 wherein: The anchor plate assembly comprises two groups of anchor plates (11), two anchor plate suspender rods (15), two groups of anchor plates (11) arranged on the anchor plate suspender rods (15), and fasteners threadedly connected to the upper and lower ends of the anchor plate suspender rods (15) and pressed on the outer side surfaces of the anchor plates (11), the center of each group of anchor plates (11) is provided with a clamping groove, the NPR steel bar (1) is clamped in the upper clamping groove, and the guide rod (12) is clamped in the lower clamping groove.

4. The reinforced concrete beam externally prestressed with NPR steel reinforcement according to claim 3, characterized in that: Adjustable thickness adjusting pads (13) are arranged between the two groups of anchor plates (11).

5. The externally prestressed reinforced concrete beam structure of NPR bars as claimed in claim 1 wherein: A plurality of protrusions (21) are arranged on the opposite surfaces of the clamp fixed block (25) and the clamp movable block (26).

6. The externally prestressed reinforced concrete beam structure of NPR reinforcement bars as claimed in claim 1, wherein: One of the temporary fixing assemblies comprises one or more independent clamping plates, and the lower part of all the clamping plates is provided with the same mounting seat (30).

7. The externally prestressed reinforced concrete beam structure of NPR reinforcing bars as claimed in claim 1, wherein: The clamp bottom plate (27) is provided with a clamp vertical block (33), the middle part of the clamp vertical block (33) is provided with a plate hole, the movable clamping device is connected to the clamp vertical block (33), and the action end of the movable clamping device is connected to the clamp movable block (26) through the plate hole; the movable clamping device is a clamp extrusion bolt (23) or an extrusion jack.

8. The externally prestressed reinforced concrete beam structure of NPR reinforcing bars as claimed in claim 1, wherein: The surface of the NPR steel bar (1) is provided with an epoxy resin coating (6), and the anchoring structure and the NPR steel bar (1) are provided with a concrete protective layer (19).

9. A method of externally prestressing a reinforced concrete beam with NPR reinforcement, characterized in that: The NPR steel bar (1) is used in the reinforced concrete beam body external prestress reinforcing structure and method, and the method comprises the following steps: Step one, according to the structure requirements and known load size, NPR steel bar (1) external prestress reinforcing design is carried out on the reinforced concrete beam structure (5) to be reinforced, and the amount and prestress size of the NPR steel bar (1) are determined; Step two, NPR steel bar (1) and anchoring structure are cut and made; Step three, the NPR steel bar (1) and the matched metal material are coated with an epoxy resin coating (6); Step four, the fixed end of the NPR steel bar (1) is positioned and anchored, and the fixed end of the NPR steel bar (1) is anchored on one end of the reinforced concrete beam structure (5) to be reinforced through the anchoring structure; Step five, the anchoring structure corresponding to the tension end is fixed on the other end of the reinforced concrete beam structure (5) to be reinforced, the NPR steel bar (1) passes through the anchoring structure but is not fixed on it. Step six, install the clamping plate fixture in the appropriate position, the clamping plate fixture clamps and fixes on the required reinforced concrete beam to be reinforced; Step seven, install the mounting seat (30) below the clamping plate fixture; Step eight, connect one end of the guide rod (12) to the mounting seat (30); Step nine, install the tensioning jack (17) and the axial force sensor (20) on the guide rod (12); Step ten, install the anchor plate assembly matched with the NPR steel bar (1), so that the NPR steel bar (1) is connected with the guide rod (12); Step eleven, tension the NPR prestressed steel bar by the jack, and use the axial force sensor (20) to monitor the applied prestress in real time, and stop tensioning when the designed prestress is reached; after tensioning is completed, the tensioning end of the NPR steel bar (1) is anchored on the anchoring structure; Step twelve, disassemble the guide rod (12), the temporary support assembly and the anchor plate assembly; Step thirteen, pour the concrete protective layer (19).

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