KR101043809B1

KR101043809B1 - Fiber reinforced polymer rod, manufacturing method thereof, and reinforcing method of concrete structure using the same

Info

Publication number: KR101043809B1
Application number: KR1020100088965A
Authority: KR
Inventors: 김중태; 장계호; 황금식
Original assignee: 동원건설주식회사
Priority date: 2010-09-10
Filing date: 2010-09-10
Publication date: 2011-06-22

Abstract

The present invention provides a method for producing a fiber-reinforced polymer reinforcement with improved performance and a repair reinforcement method for concrete structures using the same. The fiber-reinforced polymer reinforcing material according to the present invention includes a core material including a resin layer and first fibers impregnated inside the resin layer along a length direction of the resin layer, and second fibers wound on an outer circumferential surface of the core material to form a spiral release node, And third fibers which are formed with a thickness smaller than the second fibers and are wound more tightly than the second fibers on the outer circumferential surface of the core material on which the second fibers are wound to form fine protrusions on the surface of the core material. The second fiber is composed of fourth fibers twisted tightly one by one, and each of the third fibers has a shape in which the first bundle and the second bundle, in which the fifth fibers are tightly packed together, are twisted together.

Description

FIBER REINFORCED POLYMER ROD, MANUFACTURING METHOD THEREOF, AND REINFORCING METHOD OF CONCRETE STRUCTURE USING THE SAME}

The present invention relates to a fiber-reinforced polymer reinforcing material, and more particularly, to a fiber-reinforced polymer reinforcing material and a method of manufacturing the same by improving the surface shape and hardening method to improve performance such as adhesion strength, shear strength, tensile strength, and modulus of elasticity. The present invention relates to a repair reinforcement method for concrete structures using the same.

Since reinforcing bars embedded in concrete cause corrosion due to various environmental factors, the strength of concrete structures is reduced. Fiber reinforced polymer (FRP) reinforcements have been developed to reinforce deteriorated concrete structures. Fiber-reinforced polymer reinforcing material has the advantage of easy construction because there is no concern about corrosion, excellent strength and light weight, and has been applied to repair and reinforce existing concrete structures in various forms such as sheets, panels, and rods.

However, the fiber-reinforced polymer reinforcement has been developed in the form of rods similar to reinforcing bars in order to overcome the structural limitations utilized only as reinforcement of existing structures, despite the many advantages described above. The rod-shaped fiber-reinforced polymer reinforcement can be widely applied to new and existing concretes.The existing concrete structures that need to increase the load capacity due to the reduced strength of the corroded steel and the new concrete structures that are installed in the environment of high corrosion resistance It is applied to increase the service life of concrete structure and reduce maintenance cost.

Fiber-reinforced polymer reinforcements have relatively low adhesion and shear strengths compared to good tensile performance. In particular, when the adhesive strength is low, it is difficult for the reinforcement to perform properly in the repair material used together with concrete or when reinforcing. Among the various methods for improving the adhesion performance of the fiber reinforced polymer reinforcement proposed in the related art, a method of imparting irregularities to the core surface by winding the second fiber on the outer circumferential surface of the core composed of the first fiber and the resin is known.

In this way, the unevenness is applied to the surface of the core by using the second fiber, thereby increasing the integrity of the core and the second fiber, and separating the second fiber from the core even when a constant load, repeated fatigue load or impact load is applied. It is very important to prevent the deterioration of the adhesion performance by preventing the loss of adhesion.

The present invention is to improve the integrity of the core material and the second fiber in the manner of imparting concavities and convexities on the core surface by using the second fiber and to prevent the separation of the second fiber to the core material for the repair material used as concrete or reinforcement To provide a fiber-reinforced polymer reinforcement to improve the adhesion performance, its manufacturing method and a concrete reinforcement method of the concrete structure using the same.

The fiber-reinforced polymer reinforcing material according to an embodiment of the present invention is a core material including the resin layer and the first fibers impregnated inside the resin layer along the length direction of the resin layer, and wound around the outer peripheral surface of the core material to form a spiral release node And two fibers and third fibers formed to a thickness smaller than the second fiber and wound more tightly than the second fiber on the outer circumferential surface of the core material on which the second fiber is wound to form fine protrusions on the surface of the core material. Each of the second and third fibers consists of a bundle of interwoven fine fibers.

The second fiber may consist of fourth fibers twisted tightly one by one. Each of the fourth fibers may be made of hydrophilic fibers. The thickness of the second fiber may be 0.08 times to 0.15 times the core diameter. The spacing of the spiral release nodes by the second fiber may be 0.9 times to 1.2 times the core diameter.

Each of the third fibers may have a form in which the first bundle and the second bundle, in which the fifth fibers are in close contact with each other, are twisted together. Each of the fifth fibers is a filament having a diameter of 5 μm to 15 μm, and each of the first bundle and the second bundle may include a plurality of filaments. Each of the third fibers may be woven to intersect with each other to bleed the excess resin of the core between the third fibers.

The fiber reinforced polymer reinforcement further includes a resin coating layer in which a surplus resin of the core material is cured, and the resin coating layer may cover the surfaces of the second fibers and the third fibers.

Fiber-reinforced polymer reinforcements can be used as a substitute for rebar in new concrete structures.

The method of manufacturing a fiber-reinforced polymer reinforcing material includes a first step of manufacturing a core material including a resin layer and first fibers impregnated inside the resin layer along a length direction of the resin layer through a resin impregnation step and a molding step, and a fourth fiber. Preparing a second fiber made by weaving one by one densely, spirally winding the outer circumferential surface of the core material with the second fiber, and a third fiber made by twisting the first bundle and the second bundle of the fifth fibers in close contact with each other. A third step of winding the core material on the outer circumferential surface of the core material while weaving the third fibers to cross each other, and a fourth step of curing the resin layer of the core material by passing the core material through a three-step hot air curing furnace having a low temperature, a medium temperature, and a high temperature. It includes.

Each of the fourth fibers may be made of hydrophilic fibers, and each of the fifth fibers may be made of a filament having a diameter of 5 μm to 15 μm. The fourth step may include a low temperature step of 40 ° C to 60 ° C, a medium temperature step of 60 ° C to 80 ° C, and a high temperature step of 80 ° C to 100 ° C.

Repair and reinforcement method of a concrete structure according to an embodiment of the present invention comprises the steps of forming a buried space with grooves in the concrete structure, disposing the aforementioned fiber-reinforced polymer reinforcement in the buried space, and fiber reinforced using an anchor Fixing the polymer reinforcement to the concrete structure, and filling the buried space with epoxy filler to finish.

When arranging the fiber-reinforced polymer reinforcement, by attaching a non-attachment tube to a portion of the fiber-reinforced polymer reinforcement can be mounted by dividing the fiber-reinforced polymer reinforcement into an attachment section and an unattachment section.

Repair and reinforcement method of the concrete structure according to another embodiment of the present invention is to remove the deterioration site of the concrete structure, disposing the above-described fiber reinforced polymer reinforcement on the concrete structure, fiber reinforced polymer reinforcement using an anchor Fixing the to the concrete structure, and applying a polymer mortar to the site where the fiber-reinforced polymer reinforcement is installed to recover or enlarge the deteriorated cross section.

Fiber-reinforced polymer reinforcement may be disposed in the concrete structure in one direction or in both directions crossing each other. The reinforcement method of the concrete structure may further include finishing applying the neutralizing protective coating after applying the polymer mortar.

Conventionally, a dual production method for forming a surface structure after heat-forming a core material and a production method for wrapping the core material with short fibers of different diameters have been used. However, the fiber-reinforced polymer reinforcement of the present embodiment uses the toughness of the fine fibers to apply the method of wrapping the core with the second fibers and the third fibers made up of the bundle of the woven microfibers so that the second fibers and the third fibers for the core The integrity and adhesion of the fibers can be increased. Therefore, it is possible to improve the adhesion performance of the fiber-reinforced polymer reinforcement to the concrete or the repair material used together, and to increase the shear in the lateral direction.

In addition, according to the present embodiment, since the surplus resin cut out to the outer surface while the second fibers and the third fibers surround the core material integrates the core material and the surface structure, additional adhesion may be exerted.

In addition, in the curing method, the core material and surface structure are formed, and then heat curing is sequentially applied in three steps, thereby increasing the number of fibers in the core material than the manufacturing method of heating and drawing the core material first. Can be improved. Therefore, even when continuous loads, repeated fatigue loads and impact loads are applied to the concrete structure, the second fibers and the third fibers are not separated from the core material, thereby effectively improving the adhesion performance of the fiber reinforced polymer reinforcement to the concrete.

The improved polymer reinforcement can be used to effectively reinforce new and existing concrete structures.

1 is an exploded perspective view showing a fiber-reinforced polymer reinforcing material according to an embodiment of the present invention.
FIG. 2 is an enlarged perspective view of the second fiber of the fiber reinforced polymer reinforcement shown in FIG. 1.
3 is a partially enlarged view of the fiber reinforced polymer reinforcement shown in FIG.
FIG. 4 is an enlarged perspective view of one of the third fibers of the fiber reinforced polymer reinforcement shown in FIG. 1.
5 is a graph showing the measurement of the adhesion strength of the fiber-reinforced polymer reinforcing material according to the change in the thickness of the second fiber with respect to the core diameter.
Figure 6 is a graph showing the measurement of the adhesion strength of the fiber-reinforced polymer reinforcement according to the change in the spacing of the spiral release section of the second fiber with respect to the core diameter.
7 is a process chart showing the manufacturing step of the fiber-reinforced polymer reinforcing material according to an embodiment of the present invention.
8 is a schematic view for explaining a method for embedding the surface of a concrete structure using a fiber-reinforced polymer reinforcement.
9 is a schematic view for explaining an unattached surface embedding method of a concrete structure using a fiber reinforced polymer reinforcement.
10 is a schematic diagram for explaining a cross-sectional enlargement (repair) reinforcement method of a concrete structure using a fiber-reinforced polymer reinforcement.
11 is a schematic view for explaining a cross-sectional repair method of a concrete structure using a fiber-reinforced polymer reinforcement.
12A, 12B, and 12C are photographs showing fiber-reinforced polymer reinforcing materials of Examples 1, 2, and 3, respectively.
13A, 13B, and 13C are photographs showing fiber-reinforced polymer reinforcing materials of Comparative Examples 1, 2, and 3, respectively.
FIG. 14 is a graph showing load test results for deflection of a non-reinforced test body and a beam test body to which the fiber-reinforced polymer reinforcing materials of Examples 1, 2 and 3 and Comparative Examples 1, 2 and 3 are applied. FIG.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

1 is an exploded perspective view showing a fiber-reinforced polymer reinforcing material according to an embodiment of the present invention.

Referring to FIG. 1, the fiber-reinforced polymer reinforcement 100 of the present embodiment includes a core 10 including a resin layer 11 and first fibers 12, and a second wound around an outer circumferential surface of the core 10. The fiber 20 and the third fibers 30 wrapped more tightly than the second fiber 20 on the outer circumferential surface of the core 10 while surrounding the second fiber 20. Each of the second fibers 20 and the third fibers 30 is not composed of a single fiber but consists of a bundle of fine fibers woven in various forms.

The core 10 is made of a resin layer 11 and first fibers 12 impregnated inside the resin layer 11 along the length direction of the resin layer 11. The resin layer 11 is formed of a thermosetting resin.

The core material 10 may be manufactured through a resin impregnation step and a molding step. The resin impregnation step is a step of supplying several strands of the first fibers 12 to a resin reservoir (not shown) to impregnate the first fibers 12 in the resin. The molding step is a step of forming the core 10 using a nozzle (not shown) having a diameter smaller than the initial thickness of the core 10 subjected to the resin impregnation step.

Core material 10 subjected to the resin impregnation step is molded to have a circular cross section of a predetermined size while passing through the nozzle. A drawer (not shown) for pulling the core 10 may be installed in front of the nozzle. Then, the core material 10 is pressed while passing through the nozzle in a state where tension is applied by a drawer, and voids in the resin layer 11 are removed in the pressing process. Since the first fibers 12 are in a tense state while maintaining the straightness in the finished core 10, the elastic modulus and tensile strength may be increased.

At this time, the thickness of the core 10 passed through the nozzle is set larger than the thickness of the final core 10. Therefore, the core material 10 in the state which passed the nozzle contains the surplus resin in the surface.

The core material 10 may be manufactured in various standards to have the same effective diameter as the deformed rebar. The core 10 is composed of 60% by volume to 70% by volume of the first fibers 12 and 30% by volume to 40% by volume of the resin layer 11, and a low temperature of 1% by weight or less of the resin layer 11. Hardeners, mesophilic curing agents, and high temperature curing agents and other additives. The first fibers 12 can be any one of carbon fiber, glass fiber, and aramid fiber.

The second fiber 20 is spirally wound around the outer circumferential surface of the core 10 to form a spiral release node. The spiral release node protrudes from the surface of the core 10 and functions as a release part of the reinforcing bar. The second fiber 20 is also wound around the outer circumferential surface of the core 10 in a strongly pulled state. As a result, a portion pressed by the second fiber 20 in the resin layer 11 is oozed out around the second fiber 20, and a bend is formed along the second fiber 20 on the outer circumferential surface of the core material 10.

As the second fiber 20 is naturally impregnated in the resin layer 11 to form a bend on the surface of the core material 10, the unity of the core material 10 and the second fiber 20 is increased, and the core material 10 is applied to the core material 10. It is possible to improve the adhesion of the second fiber 20 to. In particular, since the second fiber 20 is made of a twisted form of fine fibers rather than short fibers, it is possible to effectively increase cutting resistance and friction resistance, thereby improving adhesion performance and improving transverse shear and separation resistance.

FIG. 2 is an enlarged perspective view of the second fiber of the fiber reinforced polymer reinforcement shown in FIG. 1.

1 and 2, the second fiber 20 consists of a bundle of fourth fibers 21 twisted one by one closely. Each of the fourth fibers 21 is hydrophilic so that the resin layer 11 of the core 10 can easily penetrate between the fourth fibers 21 to increase the adhesion of the second fiber 20 to the core 10. Made of fibers. The fourth fibers 21 are tightly twisted in a state of minimizing voids between each other to constitute the second fiber 20.

In FIG. 2, the eight fourth fibers 21 are twisted one by one to form the second fiber 20, but the number and twisting manner of the fourth fibers 21 are limited to the illustrated example. It is not possible and can be variously modified.

The second fiber 20 composed of the twisted fourth fibers 21 has structurally stronger characteristics compared to the case composed of short fibers, and forms much more surface irregularities. Therefore, after the second fiber 20 is wound on the core material 10, the fiber-reinforced polymer reinforcement 100 may be effectively prevented from being cut by the load or separated from the core material 10 in the process of being used in an actual concrete structure. .

Referring back to FIG. 1, the thickness of the second fiber 20 may be set to 0.08 times to 0.15 times the diameter d1 of the core material 10. And the spacing (G) of the spiral release section by the second fiber 20 may be set to 0.9 times to 1.2 times the diameter (d1) of the core material (10).

When the thickness of the second fiber 20 is less than 0.08 times the diameter d1 of the core material 10, the adhesion performance of the fiber-reinforced polymer reinforcement 100 to concrete is reduced, and the thickness of the second fiber 20 is the core material ( 10) When the diameter d1 exceeds 0.15 times, the degree of the third fibers 30 to adhere the second fibers 20 to the core 10 is weakened, so that the fiber-reinforced polymer reinforcement 100 for concrete is also reduced. Adhesion performance is reduced.

And when the distance (G) of the spiral release section is less than 0.9 times the diameter (d1) of the core material 10, the degree of adhesion of the third fibers 30 to the core material 10 is weakened, so that the fiber-reinforced polymer reinforcement for concrete ( 100) decreases the adhesion performance, and if the spacing (G) of the spiral release section exceeds 1.2 times the diameter (d1) of the core material 10, the number of nodes per unit length of the fiber-reinforced polymer reinforcement (100) decreases, so The adhesion performance of the fiber reinforced polymer reinforcement 100 is reduced.

3 is a partially enlarged view of the fiber reinforced polymer reinforcement shown in FIG.

Referring to FIGS. 1 and 3, the third fibers 30 are more tightly wound on the outer circumferential surface of the core 10 than the second fibers 20 while surrounding the second fibers 20. The third fibers 30 are woven to cross each other at right angles or at various other angles. That is, the third fibers 30 are woven in a grid or mesh form to surround the core 10, and the thickness of each of the third fibers 30 is smaller than the thickness of the second fibers 20. The wound third fibers 30 function as a surface protective layer and form numerous fine protrusions 40 on the surface of the core 10.

The third fibers 30 are also wound around the outer circumferential surface of the core 10 in a pulled state. As a result, the surplus resin of the core material 10 is pressed and discharged by the third fibers 30 to protrude convexly between the third fibers 30, and the surplus resin oozed out simultaneously covers the third fibers 30 naturally. . Therefore, a number of fine protrusions 40 are formed on the surface of the core 10, and a resin coating layer 41 is formed to surround the second fibers 20 and the third fibers 30.

As a result, it is possible to increase the integrity of the third fibers 30 to the core 10, and to increase the adhesion of the third fibers 30 to the core 10. In addition, the third fibers 30 increase the adhesion strength of the fiber-reinforced polymer reinforcement 100 to concrete by providing a large number of uneven structures on the surface of the core 10.

At this time, each of the third fibers 30 is composed of a bundle of fine fibers rather than short fibers like the second fiber 20. FIG. 4 is an enlarged perspective view of one of the third fibers of the fiber reinforced polymer reinforcement shown in FIG. 1.

Referring to FIG. 4, each of the third fibers 30 includes a first bundle 32 and a second bundle 33 in which the fifth fibers 31 are in close contact with each other, and the first bundle 32 and the first bundle 32. The second bundle 33 is twisted together to constitute the third fiber 30. Each of the fifth fibers 31 may be a filament having a diameter of 5 μm to 15 μm, and the first bundle 32 and the second bundle 33 may include a plurality of filaments.

The third fiber 30 composed of the first bundle 32 and the second bundle 33 has structurally stronger characteristics compared to the case composed of short fibers, and forms much more surface irregularities. As a result, the third fibers 30 are more tightly fixed to the core 10, and the core 10 is compressed at a higher pressure to allow more surplus resin to be drawn out between the third fibers 30. 20 and the third fibers 30 are more smoothly coated with the resin layer 11.

As such, the fiber-reinforced polymer reinforcement 100 according to the present exemplary embodiment comprises each of the second fibers 20 and the third fibers 30 as a bundle of fine fibers, so that the second fibers 20 with respect to the core material 10. And the integrity and adhesion of the third fibers 30 can be improved.

Accordingly, even when the fiber-reinforced polymer reinforcement 100 is applied to concrete, the second fiber 20 and the third fibers 30 are not separated from the core 10 even when a continuous load or repeated fatigue load and impact load are applied. Doing so can effectively improve the adhesion performance of the fiber-reinforced polymer reinforcement 100 to the concrete.

5 is a graph showing the measurement of the adhesion strength of the fiber-reinforced polymer reinforcing material according to the change in the thickness of the second fiber with respect to the core diameter. In FIG. 5, the lines A, B, C, D, and E respectively mean that the spacing of the spiral release nodes of the second fiber is 0.8 times, 0.9 times, 1 times, 1.2 times, and 1.4 times when the core diameter is 0.8 times the core diameter. do.

Referring to FIG. 5, as the thickness ratio of the second fiber to the core diameter increases, the adhesion strength of the fiber-reinforced polymer reinforcement increases, and when the thickness ratio of the second fiber to the core diameter is 0.12 tends to fall back to the highest point. Seems. The bond strength of the fiber-reinforced polymer reinforcement is about 15 MPa or more in the range where the thickness of the second fiber is 0.08 to 0.15 times the core diameter.

At this time, the adhesion strength of the fiber-reinforced polymer reinforcing material shows a larger value as the spacing between the spiral release nodes of the second fiber is closer to 1 times the core diameter, and lower as the distance from 1 times. In particular, the A-line (0.8 times) and the E-line (1.4 times) show a significantly lower bond strength, so the spacing of the spiral release nodes of the second fiber is 0.9 to 1.2 times the diameter of the remaining lines except for the A and E lines, that is, the core diameter. Pear is preferred. In this case, the adhesion strength of the fiber reinforced polymer reinforcing material is approximately 17 MPa or more.

Figure 6 is a graph showing the measurement of the adhesion strength of the fiber-reinforced polymer reinforcement according to the change in the spacing of the spiral release section of the second fiber with respect to the core diameter. In FIG. 6, F, G, H, I, and J lines each mean the thickness of the second fiber is 0.06 times, 0.1 times, 0.12 times, 0.14 times, and 0.18 times the core diameter.

Referring to FIG. 6, as the spacing of the spiral release nodes of the second fiber with respect to the core diameter increases, the adhesion strength of the fiber-reinforced polymer reinforcement tends to gradually decrease after a gentle rise. The bond strength of the fiber-reinforced polymer reinforcement is about 14 MPa or more in the range where the spacing of the spiral release nodes of the second fiber is 0.9 to 1.2 times the core diameter.

At this time, the adhesion strength of the fiber-reinforced polymer reinforcing material shows a larger value as the thickness of the second fiber is closer to 0.12 times the core diameter, and lower as it moves away from 0.12 times. In particular, the F line (0.06 times) and J line (0.18 times) shows a significantly lower adhesion strength, the thickness of the second fiber is preferably 0.1 times to 0.14 times the diameter of the remaining line, except the F line and J line, the core material diameter. In this case, the adhesion strength of the fiber reinforced polymer reinforcing material is approximately 17 MPa or more.

7 is a process chart showing the manufacturing step of the fiber-reinforced polymer reinforcing material according to an embodiment of the present invention.

Referring to FIG. 7, the method of manufacturing a fiber reinforced polymer reinforcement includes a first step S10 of manufacturing a core material, a second step S20 of spirally winding a second fiber on an outer circumferential surface of the core material, and a spiral release node; In the third step (S30) of winding the outer circumferential surface of the core material while weaving the third fibers to cross each other, and the fourth step of curing the resin layer of the core material by passing the core material passed through the third step through a three-step hot air curing furnace ( S40).

In the first step S10, the core material 10 includes a resin layer 11 and first fibers 12 impregnated inside the resin layer 11 along a length direction of the resin layer 11. The first step S10 may include the above-described resin impregnation step and a molding step using a nozzle.

In the second step S20, the second fiber 20 is made of fourth fibers 21 twisted one by one. In the third step S30, each of the third fibers 30 has a shape in which the first bundles 32 and the second bundles 33, in which the fifth fibers 31 are in close contact with each other, are twisted together. The second step S20 and the third step S30 may be performed using a conventional winding machine (not shown).

The fourth step S40 of curing the resin layer 11 includes a low temperature step, a medium temperature step, and a high temperature step. The low temperature step is performed at a temperature condition of 40 ° C to 60 ° C, and promotes the excess resin of the resin layer 11 to be discharged from the center portion to the surface to clean the surface of the second fiber 20 and the third fibers 30. It's a step to envelop.

The intermediate temperature step is performed at a temperature condition of 60 ° C to 80 ° C, and is a step of integrating the second fiber 20 and the third fibers 30 while the resin is gradually cured from the surface. The high temperature step is carried out at a temperature condition of 80 ℃ to 100 ℃, the thermosetting resin is a step to complete all the curing reaction.

As a result of the above three-step curing process, the possibility of voids in the core 10 is completely blocked to remove the strength deterioration factor of the fiber-reinforced polymer reinforcement 100, and the second fiber (for the core 10) 20) and the integration of the third fibers 30 can be effectively implemented.

If the low temperature step and the intermediate temperature step are omitted and the resin layer 11 is cured at a temperature of 100 ° C. or more, the resin layer 11 inside the core material 10 boils and a large number of voids are generated, thereby reducing the strength. On the other hand, when the resin layer 11 is cured only at a low temperature step, a considerable time is required to completely cure the resin layer 11, thereby lowering the productivity.

Next, as a reinforcing method of the concrete structure using the fiber-reinforced polymer reinforcing material 100 having the above-described configuration, a surface embedding method, an unattached surface embedding method, a cross-sectional enlargement (recovery) reinforcing method, and a cross-sectional repair method will be described.

8 is a schematic view for explaining a method for embedding the surface of a concrete structure using a fiber-reinforced polymer reinforcement.

Referring to Figure 8, the fiber-reinforced polymer reinforcing material 100 is used in the concrete structure 201 reduced the usability due to the lack of load capacity. In detail, a buried space 51 is formed in the concrete structure 201 as a trench within the thickness of the reinforcing bar, and an anchor hole is formed in one surface of the concrete structure 201 facing the buried space 51, and the buried space is formed. The fiber-reinforced polymer reinforcement 100 is disposed on the 51, the fiber-reinforced polymer reinforcement 100 and the J-type anchor 52 are assembled, and then the J-type anchor 52 is hit by the anchor hole to make the fiber-reinforced polymer reinforcement ( 100 is fixed to the concrete structure 201, the filling of the buried space 51 with the epoxy filler 53 is finished.

At this time, the brand name DWCR, DWGR, DWHR of the manufacturer Dongwon Construction Co., Ltd. can be used as the fiber reinforced polymer reinforcing material (100), and the brand names DWE-201, DWE-202, DWE-203 of the manufacturer Dongwon Construction Co., Ltd. can be used as the epoxy filler (53). Can be.

This surface reclamation method is different from the conventional method of attaching the fiber-reinforced polymer reinforcement (100) to only one side of the surface of the concrete structure in the form of a sheet, plate, or panel, three surfaces into the interior without covering the construction front of the concrete structure (201) Since it is buried in a wrapping form to maintain the breathability has the advantage of easy maintenance. Therefore, separation of the reinforcing surface does not occur until the concrete structure 201 is destroyed, thereby obtaining an excellent reinforcing effect.

9 is a schematic view for explaining an unattached surface embedding method of a concrete structure using a fiber reinforced polymer reinforcement.

Referring to FIG. 9, the non-attached surface embedding method is to attach the non-attached tube 54 to a part of the fiber reinforced polymer reinforcement 100 so that the fibre-reinforced polymer reinforcement 100 is divided into attachment sections and non-attachment sections. Except for the above-described surface filling method. In this case, the ductile behavior effect can be obtained as compared with the complete attachment method shown in FIG. That is, the strain according to the load is evenly distributed in the fiber-reinforced polymer reinforcing material 100 according to the length of the non-attachment section can suppress brittle fracture. Therefore, the safety and structural reliability of the concrete structure 202 can be improved.

10 is a schematic diagram for explaining a cross-sectional enlargement (repair) reinforcement method of a concrete structure using a fiber-reinforced polymer reinforcement.

Referring to FIG. 10, the fiber reinforced polymer reinforcement 100 is used in the concrete structure 203 where the load capacity deficiency and cross-sectional degradation occur simultaneously. Specifically, the deterioration site of the concrete structure 203 is removed, an anchor hole is formed on one surface of the concrete structure 203, and the fiber-reinforced polymer reinforcement 100 is disposed on the concrete structure 203 in one or two directions, After assembling the fiber reinforced polymer reinforcement 100 and the J-type anchor 52, the J-type anchor 52 is hit by the anchor hole to fix the fiber-reinforced polymer reinforcement 100 to the concrete structure 203, and then The polymer mortar 55 is filled and finish applied with a neutralizing protective coating (not shown).

In this case, it is possible to simultaneously obtain the effect of improving the cross-section of the concrete structure and the load capacity. The process can only recover or expand as necessary to the rebar cover thickness.

11 is a schematic view for explaining a cross-sectional repair method of a concrete structure using a fiber-reinforced polymer reinforcement.

Referring to FIG. 11, the fiber reinforced polymer reinforcement 100 is used for a concrete structure 204 that requires a wide range of repairs. Specifically, the portion of the concrete structure 204 needs to be removed, an anchor hole is formed on one surface of the concrete structure 204, and the fiber-reinforced polymer reinforcement 100 is disposed on the concrete structure 204 in one or two directions. Then, the fiber-reinforced polymer reinforcement 100 and the J-type anchor 52 are assembled, and then the J-type anchor 52 is hit by the anchor hole to fix the fiber-reinforced polymer reinforcement 100 to the concrete structure 204, Fill the polymer mortar 55 with a spray and finish apply with a neutralizing protective coating (not shown).

In the cross-sectional enlargement reinforcement method and surface repair method shown in Figs. 10 and 11, the brand name DWCR, DWGR, DWHR of the manufacturer Dongwon Construction Co., Ltd. can be used as the fiber-reinforced polymer reinforcement 100, and the manufacturer mobilization as the polymer mortar 55 The trade names DWP 101 and DWP 102 may be used. In addition, the brand name DW-302 of Dongwon Construction Co., Ltd. can be used as a neutralizing protective coating.

The fiber-reinforced polymer reinforcement 100 described above is used as a replacement for reinforcing steel in new concrete structures as well as for repairing existing concrete structures. In particular, the fiber-reinforced polymer reinforcing material 100 is used in concrete structures that have a risk of corrosion of the steel bars or the use of steel bars is limited.

Specifically, the fiber-reinforced polymer reinforcement 100 is concrete exposed to deicing salt (bridge deck, rail rail support, central partition, parking lot, etc.), concrete exposed to salt (breakwater, moisture, coastal structures, offshore structures, etc.), And concrete near an electromagnetic field (MRI room of a hospital, a control tower of an airport, a structure near a high voltage line or a transformer, etc.).

Next, the performance test results of the fiber-reinforced polymer reinforcement of the present embodiment and the fiber-reinforced polymer reinforcement of the comparative example will be described.

First, the fiber-reinforced polymer reinforcement of Examples 1, 2 and 3 and the fiber-reinforced polymer reinforcement of Comparative Examples 1, 2 and 3 used in the experiment will be described. 12A, 12B, and 12C are photographs showing the fiber-reinforced polymer reinforcing materials of Examples 1, 2, and 3, respectively, and FIGS. 13A, 13B, and 13C show the fiber-reinforced polymer reinforcing materials of Comparative Examples 1, 2, and 3, respectively. The picture shown.

Table 1 shows the characteristics of the fiber reinforced polymer reinforcement of Examples 1, 2, 3 and Comparative Examples 1, 2, 3.

Guide Test Methods for Fiber-Reinforced Polymer (FRPs) for Reinforcing of the Fiber Reinforced Polymer Reinforcements of Examples 1, 2, 3 and Comparative Examples 1, 2, 3 Performance was compared by Strengthening Concrete Structures.

First, tensile properties and adhesion performance of the fiber reinforced polymer reinforcement of Examples 1, 2 and 3 and the fiber reinforced polymer reinforcement of Comparative Examples 1, 2 and 3 were tested, and the results are shown in Tables 2 and 3 below.

Referring to Table 2, the tensile strength of the fiber-reinforced polymer reinforcement of Examples 1, 2, 3 is 13.8% to 51.5% improvement compared to the fiber-reinforced polymer reinforcement of Comparative Examples 1, 2, 3, the elastic modulus is 15.8% to 25.3 % You can see the improvement. And referring to Table 3, it can be seen that the adhesion performance of the fiber reinforced polymer reinforcement of Examples 1, 2, 3 is 1.08 times to 1.17 times improved compared to the fiber reinforced polymer reinforcement of Comparative Examples 1, 2, 3.

The foregoing results indicate that the structural properties of the fiber-reinforced polymer reinforcement of the embodiments are each composed of a bundle of interwoven fine fibers instead of single fibers, and the second and third fibers are wound on the outer peripheral surface of the core. It is mainly due to the manufacturing characteristics of the post-curing method that transfers heat to the air by passing through a post-heating hot stove. The fiber-reinforced polymer reinforcements of Examples 1, 2 and 3 had a tougher and more robust surface structure than Comparative Examples 1, 2 and 3.

Next, the shear stress of the fiber-reinforced polymer reinforcement of Examples 1, 2, 3 and the fiber-reinforced polymer reinforcement of Comparative Examples 1, 2, 3 was tested, the results are shown in Table 4 below.

Referring to Table 4, it can be seen that the shear stress of the fiber-reinforced polymer reinforcement of Examples 1, 2 and 3 is improved by 10.4% to 34.1% compared to the fiber-reinforced polymer reinforcement of Comparative Examples 1, 2 and 3. This result is due to the improved cut resistance in the transverse direction by the second and third fibers surrounding the core in the fiber reinforced polymer reinforcement of the embodiments.

Next, in order to compare the flexural behavior of concrete structures according to the reinforcement method, a standard beam test specimen was manufactured as shown in Table 5 below, and the surface embedding, unattached surface embedding, and cross-sectional enlargement (recovery) reinforcement method were applied as shown in Table 6 below. Relative evaluation was performed after calculating the maximum strength, ductility, and energy absorption.

Ductility (D) was calculated as the ratio of the deflection value (Δu) at the maximum load to the deflection value (Δy) at yield as shown in the following formula (1).

--- (One)

In addition, as shown in the following formula (2), the load-deflection area A of the beam was obtained to calculate the energy absorption amount of the reinforced test specimen.

---(2)

Here, P (Δ) represents the load against deflection, Δ represents the deflection of the beam, and Δc represents the deflection at the time of sudden decrease in the strength of the beam.

Table 7 shows the results of evaluation of the maximum strength, ductility, and energy absorption of the beam test bodies to which the fiber-reinforced polymer reinforcements of Examples 1, 2, 3 and Comparative Examples 1, 2, and 3 were respectively applied, and FIG. The load test results are shown. In Figure 14, 'standard' refers to a test body without reinforcing material.

Referring to Table 7 and FIG. 14, the test specimens of Comparative Examples 1, 2, and 3 have improved the maximum strength of 1.79 to 1.89 times compared to the non-reinforced specimens, but show brittle fractures after the maximum load because brittle fracture occurs due to the properties of the material. . On the other hand, the test specimens of Examples 1, 2, and 3 exhibited superior reinforcing effects of 2.67 times to 2.08 times compared to the non-reinforced specimens. This is because the behavior has been changed to a more stable behavior.

In addition, the test bodies of Examples 1, 2, and 3 are 1.18 times to 1.5 times improved in ductility compared to Comparative Examples 1, 2 and 3, and 1.14 times to 1.58 times improved in energy absorption.

Comparing the reinforcing effects between the methods, the test body of Example 2 to which the unattached surface embedding method was applied was 1.07 times and 1.1 times higher in ductility and energy absorption than the test body of Example 1 to which the surface embedding method was applied. This is because the deformation of the fiber-reinforced polymer reinforcement is dispersed within the non-attachment section, thereby ductilely inducing the characteristics of the brittle reinforcement. On the other hand, the test sample of Example 1 and the test sample of Example 3 to which the cross-sectional enlargement (recovery) method was applied showed excellent performance without significant performance difference.

As such, the fiber-reinforced polymer reinforcement of the present embodiment may be applied by various methods according to the conditions of the concrete structure, thereby effectively improving the stability of the concrete structure.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Of course.

100: fiber reinforced polymer reinforcing material 10: core material
11: resin layer 12: first fibers
20: second fiber 21: fourth fibers
30: third fiber 31: fifth fibers
32: first bundle 33: second bundle
40: fine protrusion 41: resin coating layer

Claims

A core material including a resin layer and first fibers impregnated inside the resin layer along a length direction of the resin layer;
A second fiber wound on an outer circumferential surface of the core material to form spiral release segments and bends on the surface of the core material; And
Third fibers which are formed with a thickness smaller than the second fibers and are tightly wound on the outer circumferential surface of the core member on which the second fibers are wound to form fine protrusions on the surface of the core member.
Including;
The second fiber is composed of fourth fibers twisted tightly one by one,
Each of the third fibers is formed in a twisted form of the first bundle and the second bundle, in which the fifth fibers are in close contact with each other,
Each of the fourth fibers is a hydrophilic fiber, each of the fifth fibers is a filament having a diameter of 5 μm to 15 μm,
The fiber-reinforced polymer reinforcement is formed on the surface of each of the second fiber and the third fiber fine unevenness of a size smaller than the bending and the fine protrusions.

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The method of claim 1,
The thickness of the second fiber is 0.08 times to 0.15 times the diameter of the core material fiber reinforced polymer reinforcement.

The method of claim 1,
The spacing of the spiral release section by the second fiber is a fiber-reinforced polymer reinforcement of 0.9 to 1.2 times the diameter of the core material.

delete

The method of claim 1,
And each of the third fibers is woven to intersect with each other to bleed excess resin of the core between the third fibers.

The method of claim 8,
Further comprising a resin coating layer cured excess resin of the core material,
The resin coating layer is fiber-reinforced polymer reinforcing material covering the surface of the second fiber and the third fibers.

The method according to any one of claims 1, 4, 5, 8, and 9,
The fiber-reinforced polymer reinforcement is a fiber-reinforced polymer reinforcement used as a substitute for reinforcing in a new concrete structure.

A first step of manufacturing a core material including a resin layer and first fibers impregnated in the resin layer along a length direction of the resin layer through a resin impregnation step and a molding step;
A second step of preparing a second fiber made by tightly weaving fourth fibers, and spirally winding the outer circumferential surface of the core material with the second fiber to form spiral release nodes and bends on the surface of the core material;
Preparing the third fibers made by twisting the first bundle and the second bundle of the fifth fibers in close contact with each other, and weaving the third fibers to cross each other, wound around the outer circumferential surface of the core to form fine protrusions on the surface of the core Third step; And
Fourth step of curing the resin layer of the core material by passing the core material through a three-step hot air curing furnace of low temperature, medium temperature, and high temperature
Including;
In the second step, each of the fourth fibers is a hydrophilic fiber, and in the third step, each of the fifth fibers is a filament having a diameter of 5 μm to 15 μm,
Surfaces of each of the second fibers and the third fibers are formed with fine concavo-convex having a smaller size than the bends and the fine protrusions,
The core material is a method of manufacturing a fiber-reinforced polymer reinforcing material that the resin is cut out while passing through the low temperature hot air curing furnace to coat the surface of the second fiber and the third fibers with a resin layer.

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The method of claim 11,
The fourth step is a method for producing a fiber-reinforced polymer reinforcing material comprising a low temperature step of 40 ℃ to 60 ℃, a medium temperature step of 60 ℃ to 80 ℃, and a high temperature step of 80 ℃ to 100 ℃.

Forming a buried space with grooves in the concrete structure;
Placing the fiber-reinforced polymer reinforcement of any one of claims 1, 4, 5, 8, and 9 in said buried space;
Fixing the fiber reinforced polymer reinforcement to the concrete structure using an anchor; And
Filling the buried space with an epoxy filler to finish
Repair reinforcement method of the concrete structure comprising a.

The method of claim 14,
When the fiber-reinforced polymer reinforcing material is disposed, by attaching a non-attachment tube to a portion of the fiber-reinforced polymer reinforcement to repair the concrete structure for mounting the fiber-reinforced polymer reinforcement divided into attached and unattached section.

Removing the deterioration site of the concrete structure;
Placing the fiber-reinforced polymer reinforcement of any one of claims 1, 4, 5, 8, and 9 above the concrete structure;
Fixing the fiber reinforced polymer reinforcement to the concrete structure using an anchor; And
Recovering or enlarging the deteriorated cross section by applying polymer mortar to the site where the fiber reinforced polymer reinforcement is installed
Repair reinforcement method of the concrete structure comprising a.

The method of claim 16,
Repair and reinforcement method of the concrete structure by arranging the fiber reinforced polymer reinforcement in one direction or in both directions to cross the concrete structure.

The method of claim 16,
After the step of applying the polymer mortar, the reinforcement method of the concrete structure further comprising the step of applying a finish with a neutralizing protective coating.