CN110607920B

CN110607920B - A stretch-draw anchor that is used for top layer to inlay prestressing force FRP lath

Info

Publication number: CN110607920B
Application number: CN201910876052.8A
Authority: CN
Inventors: 彭晖; 龚爽; 张建仁; 刘扬; 王磊; 粟淼; 单韧; 彭勃
Original assignee: Hunan Good Bond Construction Technic Development Co ltd; Changsha University of Science and Technology
Current assignee: Hunan Gutebang Civil Engineering Technology Development Co., Ltd; Changsha University of Science and Technology
Priority date: 2019-09-17
Filing date: 2019-09-17
Publication date: 2022-01-14
Anticipated expiration: 2039-09-17
Also published as: CN110607920A

Abstract

A tensioning and anchoring device for embedding and pasting a prestressed FRP plank on the surface layer comprises a tensioning end base, a fixed end base, a tensioning end FRP plank clamp and a fixed end FRP plank clamp, wherein the fixed end FRP plank clamp is fixedly arranged on the fixed end base; the tensioning end base comprises a first bottom plate, a first baffle and a second baffle; two tensioning end screws are arranged on the tensioning end base, each tensioning end screw sequentially penetrates through the first baffle, the tensioning end FRP batten clamp and the second baffle, a second nut is arranged at one end of each tensioning end screw, a third nut is arranged at the other end of each tensioning end screw, and the second nut is located between the tensioning end FRP batten clamp and the second baffle; and the tensioning end screw rod is also provided with a pushing device. According to the invention, the tensioning-end FRP slab clamp is fixed on the tensioning-end base through the screw assembly, and the tensioning-end FRP slab clamp and the FRP slab can be driven to move by the pushing device or by screwing the third nut, so that the prestress tensioning of the FRP slab is realized.

Description

A stretch-draw anchor that is used for top layer to inlay prestressing force FRP lath

Technical Field

The invention belongs to the technical field of reinforcement of concrete structures, and particularly relates to a tensioning and anchoring device for embedding a prestressed FRP (fiber reinforced plastic) lath on a surface layer.

Background

The Fiber Reinforced Plastic (FRP) is widely applied to the bending resistance and reinforcement of a concrete structure due to the excellent performances of light weight, high strength, corrosion resistance and the like, and the FRP is adhered to the surface of a tensile area of a reinforced structure, so that the bearing capacity and the durability of the reinforced member can be effectively improved. However, the FRP has very high strength and very low modulus, and the material strength of the FRP can only exert 10% -20% when the steel bars are yielding when the FRP is used for reinforcing a reinforced concrete structure, so that prestress is required to be applied to the FRP to exert the strength in advance so as to fully utilize the high-strength performance of the FRP. In recent years, the surface-adhered (externally-adhered) prestressed FRP technology has been developed and applied, but this technology usually requires a special permanent anchor to anchor the FRP (especially for the plate and the rib with large section rigidity), thereby increasing the cost of the technology. The FRP technique is another FRP reinforcing technique developed in recent years, in which a groove is formed in the surface of a reinforced concrete structure (in a concrete protective layer), an FRP rib or a slab is embedded therein, and the FRP rib or the slab is tightly bonded to the structural concrete by an adhesive. Compared with the externally-bonded FRP with a single surface bonded, the three-surface bonding mode of surface layer embedding greatly improves the bonding strength between the FRP and the concrete, so that the anchoring of the prestressed FRP can be realized by utilizing the powerful bonding between the surface layer embedding FRP and the concrete. Compared with the externally-attached prestressed FRP, the surface-layer-attached prestressed FRP does not need to be provided with a special permanent anchorage device, so that the cost for reinforcing the prestressed FRP is reduced, the possible risk caused by the durability degradation of the anchorage device is avoided, and the externally-attached prestressed FRP has remarkable advantages in economy and safety.

The key of the technology is that the FRP is clamped and anchored, tensioned and fixed and the binder is cured in the limited space of a concrete protective layer (about 25 mm-35 mm), the existing tensioning and anchoring system basically cannot realize the clamping and anchoring of the FRP in the narrow space and cannot perform tensioning in a tank for installing the FRP, and the application and popularization of the technology in actual engineering are limited.

The invention provides a tensioning and anchoring device for embedding prestressed FRP on a surface layer on the basis of the invention patent ZL201110259583.6, and aims to realize hardware facilities of the technology for reinforcing the prestressed FRP on the surface layer.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: aiming at the technical problems existing in the prior art, the tensioning and anchoring device which is simple in structure, convenient and efficient to assemble, capable of being repeatedly used and convenient to construct and suitable for the surface layer embedded prestressed FRP strip is provided.

The technical scheme adopted by the invention is as follows: a tensioning and anchoring device for embedding and pasting a prestressed FRP plank on the surface layer comprises a tensioning end base, a fixed end base, a tensioning end FRP plank clamp and a fixed end FRP plank clamp, wherein the fixed end FRP plank clamp is fixedly arranged on the fixed end base; the tensioning end base comprises a first bottom plate, a first baffle and a second baffle, wherein the first baffle and the second baffle are arranged on the first bottom plate; two tensioning end screw rods which are arranged in parallel are arranged on the tensioning end base, each tensioning end screw rod sequentially penetrates through the first baffle, the tensioning end FRP slab clamp and the second baffle, a second nut is arranged at one end of each tensioning end screw rod, a third nut is arranged at the other end of each tensioning end screw rod, and the second nut is located between the tensioning end FRP slab clamp and the second baffle; and a reaction plate is arranged on the tensioning end screw rod and positioned between the third nut and the first baffle, and a pushing device is arranged between the first baffle and the reaction plate.

According to the invention, the tensioning-end FRP slab clamp is fixed on the tensioning-end base through the screw assembly, and the tensioning-end FRP slab clamp and the FRP slab can be driven to move by the pushing device or by screwing the third nut, so that the prestress tensioning of the FRP slab is realized.

Preferably, the first base plate is provided with a first bolt for fixing the tensioning end base on the concrete structure.

Preferably, the jacking device is a jack.

Preferably, a force sensor is arranged between the reaction plate and the jack.

Preferably, the fixed end base comprises a second bottom plate, a third baffle and a fourth baffle, wherein the third baffle and the fourth baffle are arranged on the second bottom plate, and a second bolt for fixing the fixed end base on a concrete structure is arranged on the second bottom plate; the fixing end base is provided with two fixing end screw rods which are arranged in parallel, each fixing end screw rod sequentially penetrates through the third baffle, the fixing end FRP slab clamp and the fourth baffle, and a first nut is arranged between the fixing end FRP slab clamp and the third baffle on each fixing end screw rod.

Preferably, the first bottom plate and the second bottom plate are both door-shaped bottom plates, and a hollow groove is formed in the middle of each door-shaped bottom plate; the first baffle and the third baffle are rectangular, stiffening ribs are arranged on the side face of the first baffle and the third baffle, the first baffle and the third baffle are arranged at one end, close to the third nut, of the door-shaped bottom plate, and the second baffle and the fourth baffle respectively comprise a left semi-elliptical plate and a right semi-elliptical plate and are arranged at the other end of the door-shaped bottom plate.

Preferably, the tensioning end FRP plank clamp comprises two clamping steel plates which are connected together through a tensioning end clamp bolt to realize the anchoring of the end part of the FRP plank, and the outer wall of each clamping steel plate is provided with an ear plate connected with a tensioning end screw; the fixed end FRP slab clamp structure is the same as the tensioning end FRP slab clamp structure.

Preferably, the two clamping steel plates comprise a first clamping steel plate and a second clamping steel plate, a first positioning pin with a convex surface is arranged on the upper part of the inner wall of the first clamping steel plate, a second positioning pin with a concave surface is arranged on the upper part of the inner wall of the second clamping steel plate, and the first positioning pin and the second positioning pin are attached to each other; the surfaces of the first clamping steel plate and the second clamping steel plate, which are in contact with the FRP plate strips, are provided with diamond grains for increasing friction.

Preferably, the outer sides of the first clamping steel plate and the second clamping steel plate are both provided with an auxiliary pressing plate, and the upper end part and the lower end part of the inner side of the auxiliary pressing plate are both provided with a first pressing strip and a second pressing strip; the first pressing strip is arranged at the position corresponding to the first positioning pin and the second positioning pin; the second batten is arranged at a position corresponding to the surface contacted with the FRP lath.

Preferably, the tensioning end FRP slat clamp and the fixed end FRP slat clamp are respectively located in empty grooves of the first bottom plate and the second bottom plate, and the vertical positions of the tensioning end FRP slat clamp and the fixed end FRP slat clamp are respectively lower than the first bottom plate and the second bottom plate.

The invention has the beneficial effects that: 1. the clamping surface of the FRP lath clamp is provided with diamond-shaped lines for increasing friction, so that the clamping effect with FRP is enhanced, and the anchoring efficiency is high; 2. positioning pins which are mutually attached are arranged on a clamping steel plate of the FRP plank clamp, so that the FRP plank can be opened and closed when being clamped; 3. the auxiliary pressing plate is arranged on the outer side of the clamp, so that the device has sufficient anchoring capability and reliability when high horizontal prestress is applied to the FRP material; 4. the FRP clamping part of the installed FRP clamp is positioned in a prefabricated groove on the surface of the concrete structure, so that the embedded tensioning and anchoring of the FRP lath are realized, and the FRP clamp has enough operation space and is convenient to construct; 5. the FRP prestress tensioning is realized by adopting a jacking jack or screwing a nut, and the controllability of operation and the uniformity of force application can be improved by arranging a force sensor; 6. the tensioning and anchoring system is formed by combining parts, is simple in structure, convenient and efficient to assemble, can be completely disassembled after the prestress is released, and is recycled, so that the cost is greatly reduced.

Drawings

FIG. 1 is a front view of the present invention in an embodiment;

FIG. 2 is a top view of the present invention in an embodiment;

FIG. 3 is a front view of the base of the tensioning end of the embodiment;

FIG. 4 is a top view of a base of the pull end of the embodiment;

FIG. 5 is a left side view of a first baffle of the embodiment;

FIG. 6 is a left side view of a second baffle of the embodiment;

FIG. 7 is a front view of an FRP plank clamp with a pull end according to an embodiment;

FIG. 8 is a top view of an embodiment of a pull end FRP plank clamp;

FIG. 9 is a left side view of a pull end FRP plank clamp of an embodiment;

FIG. 10 is a schematic view of another embodiment of an FRP plank clamp with tensioning ends;

FIG. 11 is a schematic view of holding a steel plate in a single-end FRP slat clamp according to an embodiment

In the figure: 1. a tension end screw rod 2 and a third nut; 3. a reaction plate; 4. a force sensor; 5. a jack; 6. a first bottom plate 7 and a first baffle plate; 8. tensioning end FRP lath clamps; 9. tensioning the end clamp bolt; 10. a first ear plate; 11. a second nut; 12. a second baffle; 13. a first bolt; 14. FRP planks; 15. a second base plate; 16. a third baffle plate; 17. a first nut; 18. fixing end FRP lath clamps; 19. a fixed end clamp bolt; 20. a second ear panel; 21. a fourth baffle; 22. A fixed end screw rod; 23. a second bolt; 24. a first positioning pin; 25. a second positioning pin; 26. an auxiliary pressure plate; 27. a first compression bar; 28. and a second pressing strip.

Detailed Description

The invention is further illustrated by the following figures and examples.

As shown in fig. 1-11, a tension anchor device for surface-embedded prestressed FRP lath comprises a tension end base, a fixed end base, a tension end FRP lath clamp 8 and a fixed end FRP lath clamp 18.

The tensioning end FRP slab clamp 8 comprises two clamping steel plates, the two clamping steel plates are connected together through a plurality of tensioning end clamp bolts 9 to realize anchoring of the end part of the FRP slab, two lug plates 10 connected with a tensioning end screw 1 are arranged on the side surface of each clamping steel plate, and diamond-shaped grains for increasing friction are arranged on the surface of each clamping steel plate, which is in contact with the FRP slab 14, so that the clamping effect is enhanced; the upper portion of the inner wall of one of the clamping steel plates is provided with a first positioning pin with a convex surface, the upper portion of the inner wall of the other clamping steel plate is provided with a second positioning pin with a concave surface, and when the two clamping steel plates are connected, the first positioning pin and the second positioning pin are mutually attached together to realize the opening and closing of the FRP plate strip.

Further, when greater prestress needs to be applied to the FRP and the width of the slot is allowed to be wider in engineering design, an auxiliary pressing plate 26 can be added on the basis of the FRP plank clamp at the tensioning end to improve the clamping effect on the FRP plank, preferably, a first pressing strip 27 and a second pressing strip 28 are arranged at the upper end and the lower end of the inner side of the auxiliary pressing plate 26, and the first pressing strip 27 is arranged at the position corresponding to the first positioning pin 24 and the second positioning pin 25; the second beads 28 are provided at positions corresponding to the surfaces in contact with the FRP planks. Meanwhile, the two auxiliary pressing plates 26 are also fixedly connected with the tensioning end FRP slab clamp 8 through tensioning end clamp bolts 9.

In this embodiment, the fixed end FRP panel clamp 18 has the same structure as the tension end FRP panel clamp 8.

The tensioning end base comprises a first bottom plate 6, a first baffle 7 and a second baffle 12, wherein the first baffle 7 and the second baffle 12 are arranged on the first bottom plate, a plurality of first bolts 13 are arranged on the first bottom plate 6, and the tensioning end base is fixed at one end of a concrete structure through the first bolts 13; the tensioning end FRP lath fixture 8 is positioned between the first baffle 7 and the second baffle 12, the left tensioning end screw 1 and the right tensioning end screw 1 on the tensioning end base sequentially penetrate through the first baffle 7, the lug plate 10 on the tensioning end FRP lath fixture 8 and the second baffle 12, a second nut 11 is fixed at a position between the tensioning end FRP lath fixture 8 and the second baffle 12 on the tensioning end screw 1, the third nut 2 at the other end of the tensioning end screw 1 is positioned outside the first baffle 7, and when the third nut 2 is screwed, the tensioning end screw 1 drives the tensioning end FRP lath fixture 8 to move, so that the FRP lath 14 is tensioned.

In the embodiment, a reaction plate 3 is arranged on the tension end screw rod 1 between the third nut 2 and the first baffle plate 7, a jack 5 is arranged between the first baffle plate 7 and the reaction plate 3, and when the tension force value is large and the requirement on the construction efficiency is high, the jacking jack 5 drives the tension end FRP slab clamp 8 to move on the tension end screw rod 1, so that prestress is applied to the FRP slab; and a force sensor 4 is also arranged between the reaction plate 3 and the jack 5 and is used for detecting the magnitude of the generated prestress.

The fixed end base comprises a second bottom plate 15, a third baffle 16 and a fourth baffle 21 which are arranged on the second bottom plate, a plurality of second bolts 23 are arranged on the second bottom plate 15, and the fixed end base is fixed at the other end of the concrete structure; the fixed end FRP lath clamp 18 is located between the third baffle and the fourth baffle, the left fixed end screw 22 and the right fixed end screw 22 which are arranged on the fixed end base sequentially penetrate through the third baffle 16, the fixed end FRP lath clamp 18 and the fourth baffle 21, a first nut 17 is further arranged at one end of the fixed end screw 22, and the fixed end FRP lath clamp 18 can be fixed by screwing the first nut 17.

In this embodiment, the first bottom plate 6 and the second bottom plate 15 are both door-shaped bottom plates, a hollow groove is formed in the middle of each door-shaped bottom plate, the tensioning end FRP slab clamp 8 and the fixed end FRP slab clamp 18 are respectively located in the hollow grooves of the first bottom plate 6 and the second bottom plate 15, and the vertical positions of the tensioning end FRP slab clamp and the fixed end FRP slab clamp are respectively lower than the first bottom plate 6 and the second bottom plate 15; first baffle 7 and third baffle 16 are rectangle trompil baffle and set up the stiffening rib in the side, the setting is close to the one end of third nut 2 on door type bottom plate, a prestressing force for undertake applying, second baffle 12 all includes left and right two blocks of semiellipse plates with fourth baffle 21, and set up the other end at door type bottom plate, respectively with first baffle 7, the cooperation of third baffle 16 is used for supporting stretch-draw end screw 1 and stiff end screw 22, and bear the pressure of transmission when stretch-draw end screw 1 and stiff end screw 22 remove.

The using method of the invention comprises the following steps: the method comprises the steps that a prefabricated groove is formed in the surface of a concrete structure to be reinforced, a fixed end base and a stretching end base are respectively installed at two ends of the prefabricated groove, a stretching end FRP slab clamp 8 and a fixed end FRP slab clamp 18 respectively extend into the prefabricated groove from empty grooves of a first bottom plate 6 and a second bottom plate 15, an FRP slab 14 is placed in the prefabricated groove, one end of the FRP slab 14 is clamped in the stretching end FRP slab clamp 8, the other end of the FRP slab is clamped in the fixed end FRP slab clamp 18, the stretching end FRP slab clamp 8 and the FRP slab 14 are driven to move outwards along a screw rod through a jacking jack 5 or a third nut 2 is screwed, and the stretching of the FRP slab is achieved, wherein the mode of screwing the third nut 2 is suitable for the condition that the jack is inconvenient to use or the stretching force value is small; the method for jacking the jack 5 is suitable for the conditions of large tension value and high requirement on construction efficiency; stopping tensioning after the target prestress is reached, and keeping the tensioning force unchanged; and (3) filling bonding resin into the groove to enable the groove to be filled with all gaps between the concrete and the FRP, so as to form three-surface bonding of the FRP and the concrete, and enabling the tensioning-end FRP strip clamp 8 and the fixed-end FRP strip clamp 18 to gradually move and retract along the screw rods 1 and 22 respectively by screwing the nuts 11 and 17 after the resin reaches the curing age, so that synchronous slow tensioning of prestress at two ends is realized, and all components are removed after the tensioning is completely finished.

Claims

1. A tensioning and anchoring device for embedding and pasting a prestressed FRP (fiber reinforced plastic) slab on a surface layer comprises a tensioning end base, a fixed end base, a tensioning end FRP slab clamp (8) and a fixed end FRP slab clamp (18), wherein the fixed end FRP slab clamp (18) is fixedly arranged on the fixed end base; the stretching end base is characterized by comprising a first bottom plate (6), a first baffle plate (7) and a second baffle plate (12), wherein the first baffle plate and the second baffle plate are arranged on the first bottom plate; the tensioning end base is provided with two tensioning end screw rods (1) which are arranged in parallel, each tensioning end screw rod (1) sequentially penetrates through a first baffle (7), a tensioning end FRP (fiber reinforced plastic) batten clamp (8) and a second baffle (12), one end of each tensioning end screw rod (1) is provided with a second nut (11), the other end of each tensioning end screw rod is provided with a third nut (2), and the second nut (11) is located between the tensioning end FRP batten clamp (8) and the second baffle (12); a reaction plate (3) is arranged on the stretching end screw (1) and positioned between the third nut (2) and the first baffle plate (7), and a pushing device is arranged between the first baffle plate (7) and the reaction plate (3);

the fixed end base comprises a second bottom plate (15), a third baffle plate (16) and a fourth baffle plate (21) which are arranged on the second bottom plate; a second bolt (23) for fixing the fixed end base on the concrete structure is arranged on the second bottom plate (15); two fixed end screw rods (22) which are arranged in parallel are arranged on the fixed end base, each fixed end screw rod (22) sequentially penetrates through the third baffle (16), the fixed end FRP slab clamp (18) and the fourth baffle (21), and a first nut (17) is arranged at a position, between the fixed end FRP slab clamp (18) and the third baffle (16), of each fixed end screw rod (22);

the first bottom plate (6) and the second bottom plate (15) are both door-shaped bottom plates, and a hollow groove is formed in the middle of each door-shaped bottom plate; the first baffle (7) and the third baffle (16) are both rectangular, stiffening ribs are arranged on the side faces of the first baffle and the third baffle, the first baffle and the third baffle are arranged at one end, close to the third nut (2), of the door-shaped bottom plate, and the second baffle (12) and the fourth baffle (21) both comprise a left semi-elliptical plate and a right semi-elliptical plate and are arranged at the other end of the door-shaped bottom plate;

the tensioning end FRP slab clamp (8) comprises two clamping steel plates which are connected together through a tensioning end clamp bolt (9) to realize the anchoring of the end part of the FRP slab; the outer wall of each clamping steel plate is provided with an ear plate (10) connected with the tensioning end screw (1); the fixed end FRP batten clamp (18) has the same structure as the tensioning end FRP batten clamp (8);

the lower parts of the tensioning end FRP slab clamp (8) and the fixed end FRP slab clamp (18) in contact with the FRP slab are respectively positioned in the empty grooves of the first bottom plate (6) and the second bottom plate (15), and the vertical positions of the tensioning end FRP slab clamp and the fixed end FRP slab clamp are respectively lower than the first bottom plate (6) and the second bottom plate (15).

2. A tension anchor for skin-inlaid prestressed FRP panels as claimed in claim 1, wherein said first bottom plate (6) is provided with first bolts (13) for fixing the tension-end base to the concrete structure.

3. A tensilely anchored device for skin-laying prestressed FRP panels according to claim 2, characterised in that the thrusting means are jacks (5).

4. A tension anchorage device for skin-inlaid prestressed FRP slat according to claim 3, characterized in that a force sensor (4) is provided between the reaction plate (3) and the jack (5).

5. A tension anchor device for surface-inlaid prestressed FRP plank as claimed in claim 1, wherein said two clamping steel plates comprise a first clamping steel plate and a second clamping steel plate, the upper part of the inner wall of the first clamping steel plate is provided with a first positioning pin (24) whose surface is convex, the upper part of the inner wall of the second clamping steel plate is provided with a second positioning pin (25) whose surface is concave, said first positioning pin and second positioning pin are mutually fitted; the surfaces of the first clamping steel plate and the second clamping steel plate, which are in contact with the FRP plate strips, are provided with diamond grains for increasing friction.

6. A tension anchor device for surface-inlaid prestressed FRP slat according to claim 5, wherein the outer sides of the first and second holding steel plates are provided with auxiliary pressing plates (26), and the upper and lower ends of the inner sides of the auxiliary pressing plates (26) are provided with first and second pressing strips (27, 28); the first pressing strip (27) is arranged at the position corresponding to the first positioning pin (24) and the second positioning pin (25); a second bead (28) is provided at a position corresponding to the surface in contact with the FRP slat.