CN211313463U

CN211313463U - FRP self-locking type end anchoring device of concrete structure

Info

Publication number: CN211313463U
Application number: CN201920827960.3U
Authority: CN
Inventors: 董坤; 刘洋; 杜德润; 蒋济同
Original assignee: Ocean University of China
Current assignee: Ocean University of China
Priority date: 2019-06-03
Filing date: 2019-06-03
Publication date: 2020-08-21
Anticipated expiration: 2029-06-03

Abstract

The utility model belongs to the technical field of civil engineering structure reinforcement, a concrete structure FRP self-locking type end anchoring device is related to, a rectangular opening is opened in the middle of the holed steel sheet, both sides of the holed steel sheet are respectively provided with a bolt hole matched with a high-strength bolt in the long edge direction, one side of the occluding fastener is provided with a projection corresponding to the size of the holed steel sheet opening, the long edges of both sides of the projection are polished into fillets, the holed steel sheet and the occluding fastener are connected into a whole at the short edge of one side through a connecting shaft, and can be freely opened and closed; the whole device can effectively anchor the fiber cloth by the external attachment method, effectively delay the peeling of the fiber cloth, avoid the reinforcing failure caused by the peeling, have simple construction and can be widely applied to various FRP materials and engineering practice.

Description

FRP self-locking type end anchoring device of concrete structure

The technical field is as follows:

the invention belongs to the technical field of civil engineering structure reinforcement, and relates to an end anchoring device of FRP cloth of a concrete structure, in particular to a self-locking type end anchoring device of FRP of the concrete structure.

Background art:

fiber Reinforced composite (FRP) materials have been widely used in the field of concrete reinforcement in recent years. Compared with the traditional reinforcement technology, the FRP cloth has the characteristics of high strength and light weight, and has good corrosion resistance, designability and fatigue resistance. The method for reinforcing the concrete member by the FRP material commonly used at present is to paste the FRP cloth on the surface of the concrete member by using epoxy resin, and the method can ensure that the FRP cloth and the concrete member have good cooperative working performance in the early stage, but with the increase of load, the method is easy to generate early end peeling damage, once the end peeling damage of the FRP cloth occurs, the peeling can rapidly expand along the FRP cloth, so that the FRP cloth falls off and completely loses the reinforcing effect, and the material performance of the FRP cannot be fully utilized.

The FRP stripping is the most main failure mode, the strengthening anchoring is a common method for solving the problem, the method can not only improve the bearing capacity of the reinforced structure and the strength utilization rate of the FRP, but also can effectively prevent or delay the early stripping of the FRP-concrete interface. The existing FRP anchoring method mainly comprises an FRP mechanical anchoring method, an FRP embedded anchoring method, an FRP-U-shaped hoop anchoring method, an FRP mixed anchoring method and the like, wherein the FRP-U-shaped hoop anchoring method utilizes a bonding agent to surround an FRP sheet along the cross section, sticks the FRP sheet to the longitudinal FRP sheet along a beam in a three-surface surrounding manner, can be transversely wrapped at the end of the FRP sheet and can also be arranged along the whole beam, the anchoring method is easy to construct, compared with the external sticking FRP method, the anchoring capability is stronger, but the anchoring method is a 'flexible' constraint on FRP cloth, the method still can generate peeling damage of the FRP cloth along with the increase of load, and the material performance of the FRP cloth can not be fully utilized; the FRP embedded anchoring method is characterized in that a groove is formed in the surface of a concrete member, an FRP material is embedded, and a binder is poured at last, and a plurality of experimental researches show that the FRP embedded anchoring method can effectively improve the bonding effect between the FRP material and the concrete member and has good anchoring capability, but the method needs to groove in the surface of the concrete member, the operation is careless, the steel bar is easy to be accidentally damaged, and a high-efficiency simple grooving technology is not provided at present, so the method cannot be widely applied; the other FRP anchoring method is a mechanical FRP anchoring method which anchors FRP materials on the surface of a concrete member through steel sheets and anchoring nails, and not only can improve the ultimate bearing capacity of the structure, but also obviously improves the ductility of the structure, however, the common FRP sheet has insufficient bearing strength for the anchoring method, and the anchoring nails can easily penetrate through the sheet to split the sheet longitudinally, so that the use of the method is limited to a certain extent; the FRP mixed anchoring method is based on the FRP mechanical anchoring method, the technology combines an external sticking method and a mechanical anchoring method, anchoring is carried out by using an anchoring part consisting of a steel plate and two concrete anchoring nails at intervals of 100mm along the whole length of the FRP cloth after the FRP cloth is pasted on the concrete surface, and test results show that most of FRP cloth used for reinforcing members is finally pulled apart, so that the strength of the FRP cloth can be fully exerted by the visible anchoring mode, but the operation of the anchoring mode is too complex, and the concrete members can be damaged to a certain extent by using a large amount of anchoring nails.

In summary, on one hand, the external FRP method cannot avoid peeling and damage of FRP and concrete, and cannot make full use of the performance of the fiber material, and on the other hand, various anchoring methods have various disadvantages and cannot be widely applied to actual FRP reinforcement engineering, so that the popularization of FRP materials in the field of civil engineering is greatly limited, and more research work needs to be carried out.

The invention content is as follows:

the invention aims to overcome the defects in the prior art, and provides a self-locking end anchoring device for FRP (fiber reinforced plastic) of a concrete structure, which can solve the problem that fiber cloth is easy to peel and damage in an externally-adhered FRP method on one hand, and can make up for short plates which are complicated in construction and seriously damage concrete members in other FRP anchoring methods on the other hand.

In order to achieve the purpose, the main body structure of the FRP self-locking type end anchoring device of the concrete structure comprises a high-strength bolt, an occlusion fastener, a steel sheet with a hole and a connecting shaft; a rectangular hole is formed in the middle of the holed steel sheet of the rectangular structure, the holed steel sheet and the long side of the rectangular hole are both polished into round corners, bolt holes matched with the high-strength bolts are respectively arranged on two sides of the holed steel sheet in the long side direction, the length of each bolt hole is twice of the diameter of the high-strength bolt, and the width of each bolt hole is the same as the diameter of the bolt; the occlusion fastener is a rectangular steel sheet with a bulge attached to the center, one side of the occlusion fastener is provided with a bulge corresponding to the size of a hole of the holed steel sheet, the long sides of the two sides of the bulge are polished into round corners, and the holed steel sheet and the occlusion fastener are connected into a whole at the short side of one side through a connecting shaft and can be freely opened and closed; when the FRP cloth is used, firstly, two sides of the FRP cloth in the width direction are pasted on a concrete member, a drill bit is used for drilling a circular hole corresponding to the center of a bolt hole on a holed steel sheet at a position close to the longitudinal edge of the FRP cloth, then an adhesive is injected into the drilled circular hole on the concrete member, and a screw rod of a high-strength bolt is fixed in the circular hole with the burial depth of 50mm-60 mm; then opening the occlusion fastener, enabling a part of the end part of the FRP cloth to pass through the bottom surface of the holed steel sheet and be folded and wrapped around the holed steel sheet in the reverse direction, and fixing the holed steel sheet and the occlusion fastener on a screw rod of the high-strength bolt after fastening the occlusion fastener; finally, soaking FRP cloth by epoxy resin, strickling and tensioning, applying torque to the nut of the high-strength bolt by a torque wrench, and firmly anchoring the whole anchoring device on the concrete member; the diameter of the screw rod of the high-strength bolt, the thickness of the occlusion fastener and the thickness of the holed steel sheet are determined according to the thickness of the adhered FRP cloth.

Compared with the prior art, the invention introduces the mechanical self-locking occlusion fastener and uses the high-strength bolt as the fastener, wherein the mechanical self-locking occlusion fastener can effectively clamp single-layer and multi-layer FRP cloth, when bearing continuously increased external load, the occlusion part of the self-locking occlusion fastener can play a self-locking effect, the clamping effect of pulling and tightening the FRP cloth is generated, and the FRP cloth is ensured not to be separated from the anchoring device along with the increase of the load. The high-strength bolt is used as a fastener to firmly anchor the whole anchoring device and the FRP cloth on the surface of the concrete member; the whole device can effectively anchor the fiber cloth by the external attachment method, effectively delay the peeling of the fiber cloth, avoid the failure of reinforcement caused by the peeling of the fiber cloth, and can continue to bear the load until the fiber cloth is broken by the anchors at two ends even if the fiber cloth is peeled, so that the utilization rate of the fiber cloth is improved, the ductility of a beam is obviously improved when the fiber cloth is damaged, the problem that the material cannot be fully utilized due to the premature peeling of the fiber cloth in the common reinforcement method is solved, and the method is simple in construction and can be widely applied to various FRP materials and engineering practice.

Description of the drawings:

fig. 1 is a schematic diagram of a principle of a vertical surface structure of the high-strength bolt of the invention.

Fig. 2 is a schematic plan view of the main structure of the present invention.

Fig. 3 is a schematic elevation view of the main structure of the present invention.

Fig. 4 is a view showing a structure of the concrete structure FRP end anchoring device according to the present invention.

Fig. 5 is a plan view showing a state of use of the FRP end anchoring device for a concrete structure according to the present invention.

The specific implementation mode is as follows:

the following detailed description of the invention refers to the accompanying drawings.

Example (b):

the main body structure of the FRP self-locking end anchoring device of the concrete structure comprises a high-strength bolt 1, an occlusion fastener 2, a hole-opening steel sheet 3 and a connecting shaft 4; a rectangular hole is formed in the middle of a hole-forming steel sheet 3 of a rectangular structure, the hole-forming steel sheet 3 and the long sides of the rectangular hole are both polished into round corners, bolt holes matched with the high-strength bolts 1 are respectively arranged on two sides of the hole-forming steel sheet 3 in the long side direction, the length of each bolt hole is twice the diameter of the high-strength bolt 1, and the width of each bolt hole is the same as the diameter of the bolt; the occlusion fastener 2 is a rectangular steel sheet with a bulge attached to the center, one side of the occlusion fastener 2 is provided with a bulge corresponding to the size of the opening of the holed steel sheet 3, the long sides of the two sides of the bulge are polished into round corners, and the holed steel sheet 3 and the occlusion fastener 2 are connected into a whole at the short side of one side through a connecting shaft 4 and can be freely opened and closed; when the high-strength bolt is used, firstly, two sides of the FRP cloth 6 in the width direction are pasted on the concrete member 5, a drill bit is used for drilling a circular hole corresponding to the center of a bolt hole on the holed steel sheet 3 at a position close to the longitudinal edge of the FRP cloth 6, then an adhesive is injected into the drilled circular hole on the concrete member 5, and a screw rod of the high-strength bolt 1 is fixed in the circular hole with the burial depth of 50-60 mm; then opening the occlusion fastener 2, enabling a part of the end part of the FRP cloth 6 to pass through the bottom surface of the holed steel sheet 3 and be folded reversely to wrap the holed steel sheet 3, and fixing the holed steel sheet 3 and the occlusion fastener 2 on a screw rod of the high-strength bolt 1 after fastening the occlusion fastener 2; finally, the FRP cloth 6 is soaked by epoxy resin and is strickleed off and tensioned, a torque wrench is used for applying torque to the nut of the high-strength bolt 1, and the whole anchoring device is firmly anchored on the concrete member 5; the diameter of the screw of the high-strength bolt 1, the thickness of the occlusion fastener 2 and the thickness of the holed steel sheet 3 are determined according to the thickness of the adhered FRP cloth 6.

Claims

1. A FRP self-locking end anchoring device of a concrete structure is characterized in that a main body structure comprises a high-strength bolt, an occlusion fastener, a steel sheet with a hole and a connecting shaft; a rectangular hole is formed in the middle of the holed steel sheet of the rectangular structure, the holed steel sheet and the long side of the rectangular hole are both polished into round corners, bolt holes matched with the high-strength bolts are respectively arranged on two sides of the holed steel sheet in the long side direction, the length of each bolt hole is twice of the diameter of the high-strength bolt, and the width of each bolt hole is the same as the diameter of the bolt; the occlusion fastener is a rectangular steel sheet with a bulge attached to the center, one side of the occlusion fastener is provided with a protrusion corresponding to the size of a hole of the holed steel sheet, the long edges of the two sides of the protrusion are polished into round corners, and the holed steel sheet and the occlusion fastener are connected into a whole at the short edge of one side through a connecting shaft and can be freely opened and closed.