KR20140141915A - Fiber Reinforced Steel Beam with End Slip Prevention Clamp - Google Patents

Abstract

The present invention relates to a steel beam reinforced with fiber reinforced plastic with an end slip prevention structure and, more specifically, to a steel beam with a clamp for preventing a reinforcing material and a steel beam from slipping when the fiber reinforced plastic reinforcing material is coupled to a lower surface of the conventional constructed steel beam due to a change in an architectural criteria for architectural structure or damage to a member caused by corrosion or collision. According to a preferable embodiment of the present invention, the steel beam reinforced with fiber reinforced plastic with an end slip prevention clamp comprises: a steel beam having an upper flange, a lower flange which is apart from and in parallel with the upper flange, and a web which is vertically arranged on the upper and lower flanges to connect the upper and lower flanges and has an H-shaped cross-section; a reinforcing material reinforced with fiber reinforced plastic which is formed of fiber reinforced plastics, has a planar shape with a predetermined thickness, and is coupled to the lower surface of the lower flange of the steel beam; and end fixing clamps which are coupled to surround the lower flange of the steel beam and the reinforcing material reinforced with fiber reinforced plastic on both end parts of the steel beam and the reinforcing material reinforced with fiber reinforced plastic and strongly couple the steel beam and the reinforcing material reinforced with fiber reinforced plastic.

Description

TECHNICAL FIELD [0001] The present invention relates to a fiber reinforced steel beam with a clamp for preventing end slip,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber-reinforced plastic reinforced steel frame having a clamp for preventing end slip, and more particularly, And a clamp for preventing the slip of the reinforcing member and the steel frame when the fiber reinforced plastic reinforcement is joined to the lower surface.

The main reinforcement methods of reinforced concrete or steel structures currently used in Korea include post-tensioning using external steel rods, and cross-section attaching methods in which steel plates or carbon fibers are directly attached to the lower part of the reinforcing structure. The reinforcement method using external steel rods is most widely applied as a method which can expect the stress generated in the structure by sag and load due to the introduction of prestressing by steel rods. However, the post-tensioning method using external steel rods has the disadvantages of stress concentration, ineffective load distribution, installation of fixed anchors, and difficulty in maintenance, although the effect of bending reinforcement is enhanced by increasing rigidity against extreme and yielding have.

In addition, the cross-section attachment method improves the cross-sectional characteristics of the structure by attaching a stiffener to the lower part of the structure, and methods using carbon fiber or steel plate have been studied. In the case of the cross-section mounting method using the steel plate, not only the workability is significantly lowered due to the use of the heavy steel plate, but also in the case where the important piping and the facility facilities such as the welding method or the bolt- Damage and electric shock caused by electricity use are a concern.

On the other hand, when carbon fiber is used as a reinforcing material, the carbon fiber is a composite material composed only of a carbon fiber sheet and an epoxy resin and has no corrosion phenomenon due to external influences such as water, salt, acid, ultraviolet rays, Effect can be expected. In particular, according to the revised seismic design criteria, reinforcement is necessary to secure the earthquake stability of the electric power supply facilities, which are the main infrastructure of the country that was built in the past. The fiber reinforced plastic reinforcement, which is an insulator under the existing steel frame, A cross-section attachment method that improves the cross-sectional characteristics of steel beams has emerged.

Adequate adhesion must be ensured in order for tensile and flexural strength to increase due to the complete synthesis of the attached carbon fibers and girders. There is a problem in that the adhesion property is decreased at the interface of the end portion of the attached member due to the bending stress after the reinforcement of the carbon fiber.

As a technology to be a background of the present invention, there is a patent registration No. 0271227 entitled " Strengthening Method of Structures by Stepwise Attachment of Stiffeners "(Patent Document 1). In the above-mentioned background art, in a reinforcing method in which a reinforcing material is attached to a structure to reinforce the structure, a stiffener made of a fiber material and having a short length from the center portion to the end portion of the reinforcing material is laminated to the structure A reinforcement method including a process "is proposed.

However, the above background art also has a problem that adhesion failure occurs at the interface between the stiffener starting from the end of the stiffener and the structure.

Patent Registration No. 0271227 "Reinforcement of Structures by Staged Attachment of Stiffeners"

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a reinforcing member made of a fiber reinforced plastic on the lower surface of a steel frame and a clamp attached to an end of the steel frame, A fiber reinforced plastic reinforced steel frame having a clamp for preventing slippage of the end portion and restraining the end portion of the slip of the end portion by restraining the joining of the steel frame and the fiber reinforced plastic reinforcement member The purpose is to provide.

A fiber-reinforced plastic reinforced steel frame with a clamp for end slip prevention according to a preferred embodiment of the present invention comprises an upper flange, a lower flange parallel to and spaced from the upper flange, a web disposed perpendicularly to the upper and lower flanges, A steel frame having a longitudinal cross-sectional shape; A fiber reinforced plastic reinforcing material formed of a fiber reinforced plastic (Plastics) and having a predetermined thickness and being joined to a lower flange bottom surface of a steel beam; A fiber reinforced plastic reinforcing member and an end restraint clamp which are coupled to each other at both ends of the steel frame to surround the steel frame lower flange and the fiber reinforced plastic reinforcement to firmly connect the steel frame and the fiber reinforced plastic reinforcement.

At this time, the end restraint clamp has a support plate parallel to the steel flange lower flange and having a greater width than the steel flange lower flange and disposed so as to abut the fiber reinforced plastic reinforcement bottom face, first and second vertical flanges A bolt which is coupled through the bolt hole of the end restraint member and the end restraint member composed of the first and second blade plates which are horizontally extended inwardly from the first and second vertical plates and threaded bolt holes are drilled; And a nut disposed on the upper surface side of the lower flange of the steel beam so as to be inserted and joined with the bolt.

On the other hand, in the end restraint clamp, a middle support plate is disposed at a central portion of the fiber-reinforced plastic reinforcement member so as to abut the lower surface of the fiber-reinforced plastic reinforcement member, and both side support plates disposed to abut the lower surface of the fiber- The bolts are bolted to the first and second vertical plates and horizontally extended to the inside of the first and second vertical plates. An end restraining member constituted by the first and second wing plates; A bolt coupled through the bolt hole of the end restraint member; And a nut which is disposed on the upper surface side of the lower flange of the steel frame and is inserted and joined with the bolt.

The end restraint clamps may have a thickness equal to the width of the fiber-reinforced plastic stiffener, a width that is equal to the width of the stiffener, a stiffener disposed to abut the fiber-reinforced plastic stiffener back, a support plate disposed to support the stiffener at both sides of the stiffener, First and second vertical plates vertically connected at both ends, and first and second blade plates horizontally extending inwardly in a cross section and threaded with bolt holes formed in the first and second vertical plates; A bolt coupled through the bolt hole of the end restraint member; And a nut disposed on an upper surface side of the lower flange of the steel frame and joined with the bolt inserted therein; The nut, the steel frame lower flange, the fiber reinforced plastic reinforcement, the plate, and the support plate can be constrained by the compression due to the rotational force applied to the bolt, so that the bottom surface of the nut fastened to the bolt is sufficiently pressed against the upper surface of the lower flange.

A fiber reinforced plastic reinforced steel frame with a clamp for end slip prevention according to the present invention comprises a reinforcing member formed of a fiber reinforced plastic on the lower surface of a steel frame, And the end portion restraining clamps are coupled with each other so as to surround the fiber reinforced plastic reinforcement member, thereby restraining the steel beam and the fiber reinforced plastic reinforcement member. Therefore, it is possible to increase the adhesion force of the end portions, thereby preventing the end portions from slipping and preventing the end portions from being damaged There is a very useful effect of increasing the load bearing capacity of the structure.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments of the invention and, together with the description, serve to explain the principles of the invention, Shall not be construed as limiting.
FIG. 1A is an exploded perspective view of a fiber-reinforced plastic reinforced steel frame with a clamp for end slip prevention according to an embodiment of the present invention, and FIG. 1B is a side sectional view of FIG. 1A.
FIG. 2A is an exploded perspective view of a fiber-reinforced plastic reinforced steel frame with a clamp for end slip prevention according to another embodiment of the present invention, and FIG.
FIG. 3A is an exploded perspective view of a fiber-reinforced plastic reinforced steel frame with a clamp for end slip prevention according to another embodiment of the present invention, and FIG. 3B is a side sectional view of FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the embodiments shown in the accompanying drawings, but the present invention is not limited thereto.

Hereinafter, the technical structure of the present invention will be described in detail with reference to the preferred embodiments.

FIG. 1A is an exploded perspective view of a fiber-reinforced plastic reinforced steel frame with a clamp for end slip prevention according to an embodiment of the present invention, and FIG. 1B is a side sectional view of FIG. 1A.

1, a fiber-reinforced plastic reinforced steel frame equipped with a clamp for preventing end slip according to the present invention includes a reinforcing member 20 formed of fiber reinforced plastics on the lower surface of a steel frame 10 Lt; / RTI > The steel frame 10 has an upper flange 11 and a lower flange 12 spaced apart from and spaced apart from the upper flange 11 and a web 13 vertically disposed on the upper and lower flanges 11 and 12 for connecting them. Wherein the fiber reinforced plastic reinforcement member 20 is formed in a shape of a plate having a width and a length equal to that of the lower flange 12 of the steel beam 10 and a lower flange 12 of the steel beam 10, .

Steel structures built before the revised seismic design criteria must be reinforced with seismic performance to meet the new standards. As part of that, primary, middle and high schools are undergoing earthquake-resistant maintenance and reinforcement. In addition, a bill for securing the earthquake - proof stability of power supply facilities, which is a major infrastructure of the country, has been prepared, and a cross - section attachment method has been emerged that improves the cross - sectional characteristics of steel beams by attaching reinforcements under the existing steel beams.

In the present invention, fiber reinforced plastic (FRP) is used as the material of the reinforcing material 20. The fiber reinforced plastic (FRP), as well as carbon fiber reinforced plastics (CFRP), aramid fiber reinforced plastic (AFRP) Kevlar fiber reinforced plastics and the like can be used.

As described above, although there are various types of FRP materials, CFRP has been used mainly for repairing and reinforcing concrete structures. FRP materials have advantages such as tensile strength characteristics of about 6 to 7 times of steel, shortening of space-time knitting, and air shortening. In order to repair and reinforce steel structures, AFRP (Aramid Fiber Reinforced Polymer), which has corrosion resistance and nonconductivity characteristics compared to CFRP, can be used as an insulator if necessary.

The fiber reinforced plastic reinforced steel frame with clamp for end slip prevention according to the present invention is characterized in that the joint of the steel fiber reinforced plastic reinforcing material 20 and the steel fiber reinforced plastic reinforcing material 20 at the ends of the steel fiber reinforced plastic 10 An end clamping clamp 30 is provided. The end restraint clamp 30 is composed of an end restraint member 31, a bolt 32 and a nut 33 which are coupled to surround the lower flange 12 of the steel frame 10 and the fiber reinforced plastic reinforcements 20.

The end restraint member 31 according to an embodiment of the present invention is fabricated to surround the lower flange 12 of the steel frame. That is, the end restraint member 31 includes a support plate 311 parallel to the steel frame lower flange 12 and having a width larger than that of the steel frame lower flange 12, and first and second And a single member having first and second wing plates 313 and 313 extending horizontally inwardly from the vertical plates 312 and 312 and the first and second vertical plates 312 and 312. The first and second wing plates 313 and 313 are formed with threaded bolt holes 313a through which the bolts 32 are engaged.

When the upper surface of the support plate 311 of the end restraint member 31 is disposed so as to abut the lower surface of the fiber reinforced plastic reinforcement member 20, the bolt 32 is partially inserted through the bolt holes 313a of the first and second blade plates 313 and 313 At this time, the nut 33 is disposed on the upper surface side of the lower steel flange 12, and then the bolt 32 is fully inserted and joined with the nut 33. The nut 33 is used to increase a supporting area in contact with the steel frame lower flange 12, and as shown in the figure, it is preferable to use a flange nut with a lower face closed. When the bolt 32 is inserted to the planned position, that is, when the bolt is rotated until the bottom surface of the nut fastened to the bolt is sufficiently pressed against the upper surface of the lower flange 12, the compression due to the rotational force applied to the bolt causes the nut The fiber reinforced plastic reinforcement member 20 and the support plate 311 are constrained so that the end side engagement between the fiber reinforced plastic reinforcement member 20 and the steel beam 10 becomes firm. When the adhesion of the fiber reinforced plastic reinforcing member 20 and the steel beam 10 is restrained by applying a pressure to the upper and lower support surfaces, the adhesion failure to the steel beam 10 starting from the end of the fiber reinforced plastic reinforcing member 20 You can prevent it from happening.

FIG. 2A is an exploded perspective view of a fiber-reinforced plastic reinforced steel frame with a clamp for preventing end slip, to which an end restraint member according to another embodiment of the present invention is applied, and FIG.

Although the end restraint member 31 constituting the end restraint clamp 30 described above is formed of one member, the end restraint member 31a constituting the end restraint clamp 30a according to the other embodiment of the present invention has three . That is, since the support plate 311 is divided into three parts as shown and the other components are the same in structure and function, the same description of other members is not repeated.

As shown in the drawing, the support plate 311 is not formed of a single plate but is provided on the both side support plates 311a connected to the both side vertical plates 312a and the blade plate 313a and the both side support plates 311a disposed on the both side support plates 311a And a central support plate 311x connected thereto. The both side support plates 311a and the center support plates 311x are formed so that the steps are formed on the connection portions so that the steps are engaged with each other.

In the case of the end restraint member 31 described earlier, there is a limit to fasten the existing structure to reinforce the existing structure because of the inconvenience of fastening to the lower part of the steel frame 10 because the end restraint member 31 is integrally manufactured. In order to solve this problem, the end restraint member 31a according to another embodiment of the present invention is manufactured such that the support plate is divided into both end portions and a central portion. Therefore, the end restraint member 31a can be easily assembled from the lower portion of the steel bar 10, have.

FIG. 3A is an exploded view of a fiber-reinforced plastic reinforced steel frame with a clamp for end slip prevention to which an end restraint member according to another embodiment of the present invention is applied, and FIG. 3B is a side sectional view of FIG.

As shown in the figure, the end restraint member 31b constituting the end restraint clamp 30b according to the present embodiment differs from the end restraint member 31a shown in FIG. Since the configuration and function are the same, the same description of the other members is not repeated.

Plates 311g having the same width as the fiber reinforced plastic reinforcement are disposed at the lower ends of the fiber reinforced plastic reinforcements 20 and the support plates 311b and 311b are disposed so as to support the lathes 311g on both sides of the lower ends of the laths 311g . The first and second vertical plates 312b and 312b and the first and second vertical plates 312b and 312b extend horizontally inwardly from both ends of the support plates 311b and 311b. The configuration of the first and second wing plates 313b and 313b is the same as the previously described embodiment.

That is, a steel plate is attached to the lower surface of the reinforcing member 20 bonded to the lower part of the steel beam 10, and the steel plates are fastened tightly with C-clamps on both sides.

The fiber-reinforced plastic reinforcing steel frame having the clamp for preventing end slip according to the present invention having the above-described structure is made by attaching a reinforcing material formed of fiber-reinforced plastic to the lower surface of the steel frame, 30a and 30b are coupled to both ends of the steel frame 10 to surround the lower flange 12 of the steel frame 10 and the fiber reinforced plastic reinforcements 20 so that the steel frame 10 and the fiber reinforced plastic Since the stiffener 20 is restrained, it is possible to increase the stiffening force of the end portion, thereby preventing the slip of the end portion and preventing the end portion of the stiffening failure beforehand, thereby enhancing the load bearing capacity of the structure.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the above teachings. will be. The invention is not limited by these variations and modifications, but is limited only by the claims appended hereto.

10: steel frame 11: steel frame upper flange
12: steel frame lower flange 13: steel frame web
20: fiber reinforced plastic reinforcement 30, 30a, 30b: end restraint clamp
31, 31a, 31b: end restraint member 311:
311x: center support plate 311g: ridge
312: vertical plate 313: wing plate
314: blade plate bolt hole 32: bolt
33: Nuts

Claims (4)

A lower flange 12 spaced apart from the upper flange 11 by a distance from the upper flange 11 and a web 13 vertically disposed on the upper and lower flanges 11 and 12 and connecting them to each other, A reinforcement steel frame 10;
A fiber reinforced plastic stiffener 20 formed of fiber reinforced plastics and joined to a lower surface of a lower flange 12 of a steel plate 10 in a plate shape having a predetermined thickness;
Reinforced plastic reinforcement member 20 and the steel frame beam 10 at both ends of the steel frame beam 10 and the fiber reinforced plastic reinforcement member 20 so as to surround the lower flange 12 and the fiber reinforced plastic reinforcement member 20, (30, 30a, 30b) for clamping the end portion of the fiber reinforced plastic reinforced steel frame with the clamp for end slip prevention. The method according to claim 1,
The end restraint clamp 30
A support plate 311 parallel to the steel frame lower flange 12 and having a larger width than the steel frame lower flange 12 and disposed so as to abut the lower surface of the fiber reinforced plastic reinforcement member 20, The first and second wing plates 313 and 313 are horizontally extended from the first and second vertical plates 312 and 312 and the first and second vertical plates 312 and 312 to form threaded bolt holes 314. An end restraint member 31 configured;
A bolt 32 coupled through the bolt hole 314 of the end restraint member 31;
And a nut 33 which is disposed on the upper surface side of the steel frame lower flange 12 and into which the bolt 32 is inserted and joined
The bottom surface of the nut 33 fastened to the bolt 32 is sufficiently tightly contacted with the upper surface of the lower flange 12 so that the nut 33 is pressed against the bottom flange 12, Wherein the reinforcing plastic reinforcement member (20) and the support plate (311) are constrained. The method according to claim 1,
The end restraint clamp 30a
The fiber reinforced plastic reinforcement member 20 is disposed so as to abut the bottom surface of the fiber reinforced plastic reinforcement member 20 at both sides of the center support plate 311x and the center support plate 311x disposed at the lower surface in the center so as to abut the lower surface of the fiber reinforced plastic reinforcement member 20 The first and second vertical plates 312a and 312a and the first and second vertical plates 312a and 312a are vertically coupled to each other at both ends of the support plates 311a and 311a, An end restraint member 31a composed of first and second wing plates 313a and 313a horizontally extended inwardly from the two vertical plates 312a and 312a and threadedly formed with bolt holes 314a;
A bolt 32 coupled through the bolt hole 314a of the end restraint member 31a;
And a nut 33 which is disposed on the upper surface side of the steel frame lower flange 12 and into which the bolt 32 is inserted and joined
The bottom surface of the nut 33 fastened to the bolt 32 is sufficiently tightly contacted with the upper surface of the lower flange 12 so that the nut 33 is pressed against the bottom flange 12, Wherein the reinforcing plastic reinforcement member (20) and the support plate (311a) are constrained. The fiber reinforced plastic reinforcing steel frame with a clamp for end slip prevention. The method according to claim 1,
The end restraint clamp 30b
A slab 311g having a predetermined thickness and the same width as the fiber reinforced plastic stiffener 20 and disposed so as to abut the lower surface of the fiber reinforced plastic stiffener 20 and a slab 311g disposed on both sides of the slab 311g to support the slab 311g The first and second vertical plates 312b and 312b and the first and second vertical plates 312b and 312b which are vertically connected vertically at opposite ends of the support plates 311b and 311b and the support plates 311b and 311b, An end restraint member 31b formed of first and second wing plates 313b and 313b extending horizontally inwardly of the end surface and threadedly formed with bolt holes 314b;
A bolt 32 coupled through the bolt hole 314b of the end restraint member 31b;
And a nut 33 which is disposed on the upper surface side of the steel frame lower flange 12 and into which the bolt 32 is inserted and joined
The bottom surface of the nut 33 fastened to the bolt 32 is sufficiently tightly contacted with the upper surface of the lower flange 12 so that the nut 33 is pressed against the bottom flange 12, Wherein the reinforcing plastic reinforcement member (20), the slab (311g), and the support plate (311b) are constrained.

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