KR101644331B1 - FRP Bar having Head, and Manufacturing Method thereof - Google Patents

FRP Bar having Head, and Manufacturing Method thereof Download PDF

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Publication number
KR101644331B1
KR101644331B1 KR1020160025397A KR20160025397A KR101644331B1 KR 101644331 B1 KR101644331 B1 KR 101644331B1 KR 1020160025397 A KR1020160025397 A KR 1020160025397A KR 20160025397 A KR20160025397 A KR 20160025397A KR 101644331 B1 KR101644331 B1 KR 101644331B1
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South Korea
Prior art keywords
frp
frp bar
bar
head
face
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KR1020160025397A
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Korean (ko)
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박영환
박성용
조정래
김성태
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한국건설기술연구원
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    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
    • E04C5/00—Reinforcing elements, e.g. for concrete; Auxiliary elements therefor
    • E04C5/07—Reinforcing elements of material other than metal, e.g. of glass, of plastics, or not exclusively made of metal
    • E04C5/073—Discrete reinforcing elements, e.g. fibres
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
    • E04C5/00—Reinforcing elements, e.g. for concrete; Auxiliary elements therefor
    • E04C5/07—Reinforcing elements of material other than metal, e.g. of glass, of plastics, or not exclusively made of metal
    • E04C5/073—Discrete reinforcing elements, e.g. fibres
    • E04C5/076—Specially adapted packagings therefor, e.g. for dosing
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
    • E04C5/00—Reinforcing elements, e.g. for concrete; Auxiliary elements therefor
    • E04C5/16—Auxiliary parts for reinforcements, e.g. connectors, spacers, stirrups

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  • Engineering & Computer Science (AREA)
  • Architecture (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Reinforcement Elements For Buildings (AREA)

Abstract

The present invention relates to a fiber reinforced polymer (FRP) stiffening member and a manufacturing method for the same. A head is installed at the end of the FRP stiffening member so that the FRP stiffening member performs a sufficient pulling resistant force without being pulled out from a concrete member when the FRP stiffening member is used by being embedded in the concrete member. A bar forming the FRP stiffening member is embedded in a concrete material such as mortar and concrete, and the head is manufactured of the concrete material. Specifically, a cutting unit is formed at the end of the FRP bar, and a contact area between the concrete material forming a block head and an FRP bar is increased. So, the block head formed of the concrete material is strongly bonded to the FRP bar, and the block head is integrated to the end of the FRP bar.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a fiber reinforced polymer reinforcing material having a concrete head,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reinforcing material (hereinafter abbreviated as "FRP reinforcing material") produced by using a fiber reinforced polymer ("FRP") and a method of manufacturing the FRP reinforcing material, (Hereinafter, referred to as "FRP reinforcing member ") of the FRP reinforcement is provided with a head at an end of the FRP reinforcement so that the FRP reinforcement can be sufficiently pulled out of the concrete member when the FRP reinforcement is embedded in the FRP reinforcement. FRP bar ") is embedded in a" concrete-based material "such as mortar, concrete, etc., and a head is manufactured using a concrete-based material. In particular, a contact area between a FRP bar and a concrete- And a head made of a concrete material is integrally formed on the end portion of the FRP bar Bidoen type of FRP reinforcement and to a manufacturing method thereof.

When a rod-shaped stiffener such as a reinforcing bar is used in a concrete structure, it is necessary to secure a sufficient resistance performance, that is, a "pull-out resistance", which resists the tensile force so that the rod- shaped stiffener is not pulled out of the concrete structure when a tensile force acts on the rod- do.

When a rod-shaped stiffener having a simple rod shape is used, this pull-out resistance is exerted only by the surface adhesion force between the rod-shaped stiffener and the concrete structure. In the case of reinforcing bars as rod-type stiffeners, in the related design standards, the fixing length when the reinforcing bars are embedded in the concrete structure is specified to secure the required pulling resistance. However, when a simple rod-shaped FRP bar is embedded in a concrete structure like a reinforcing bar, it is often difficult to secure a fixation length required by the design standard on the FRP bar due to the characteristics of the concrete member or the shape constraint conditions. It may not be possible to secure enough pulling resistance for the bar.

Particularly, in the case of reinforcing bars, it is possible to secure necessary pull-out resistance by bending end portions in the form of hooks. However, in the case of a FRP bar made of a thermosetting resin, it is not easy to bend like a reinforcing bar. Since the thermosetting resin has a characteristic that it is not easily deflected in a cured state, it is not possible to form the FRP bar using a thermosetting resin and to bend the FRP bar like a reinforcing bar in a state where the curing of the thermosetting resin is completed. For this reason, it is necessary to bend the FRP bars in a desired shape before the thermosetting resin is fully cured in the manufacturing process in order to manufacture the bending FRP bars in which the ends are bent like a reinforcing bar. In this case, a special bending device and other equipment are required. The manufacturing cost of the bar is considerably increased, and the price of the bending FRP bar is greatly increased. Above all, when the FRP bar is bent, the outer side of the bent portion is in a tensile state, and the inside of the bent portion is in a compressed state, so that the tensile strength of the FRP bar itself is significantly lowered, do.

As a solution to this, a method of attaching a separate head integrally to the end of the FRP bar has been proposed. Korean Patent Laid-Open No. 10-2010-49195 discloses an FRP reinforcement in which a head is formed by threading an end surface of a FRP bar and a head having a fastening groove formed with a thread is screwed to an end of the FRP bar. However, in the actual case, it is known that the pull-out resistance force exhibited by the conventional FRP reinforcement having such a screw-coupled head is only about 60% of the maximum break load of the FRP bar. That is, the entire FRP stiffener, including the head, will be pulled out of the concrete structure well before the FRP bars are broken by tensile forces.

In case of FRP stiffener with screwed head, the diameter and size of the head must be increased if the diameter of the FRP bar is increased. Since the head is made of expensive plastic material or FRP member, Resulting in a decrease in economic efficiency. Particularly, since the head is made of a plastic material or a FRP member, when the FRP stiffener having a threaded head is embedded in the concrete structure, there is a problem in adhesion between the plastic material of the head or the FRP member and the concrete due to the dissimilar materials There is a drawback that it can occur again.

Korean Patent Publication No. 10-2010-49195 (published on May 12, 2010).

The present invention has been developed in order to overcome the limitations of the prior art as described above. Specifically, the present invention provides a reinforcing material embedded in a concrete structure and having a head integrally formed at an end of the FRP bar so as to exhibit a sufficient pull- When a FRP reinforcement with a head is embedded in a concrete structure by providing a type of FRP stiffener by making a head using a "concrete material" such as concrete or mortar, a heterogeneous structure is formed between the head and the concrete structure, So that they can be easily bonded together without any problem of adhesion due to the material.

It is still another object of the present invention to provide a technique capable of manufacturing a FRP reinforcement by firmly integrating a head having a required cross-sectional shape and cross-sectional size in a field on an FRP bar.

According to the present invention, there is provided a method of manufacturing an FRP reinforcement comprising a bar-shaped FRP bar and a block head integrally provided at the end of the FRP bar so that the end of the FRP bar is embedded, The end of the FRP bar is formed with a plurality of cutouts extending in the longitudinal direction starting from the final end face to cut the end of the FRP bar such that the final end face of the FRP bar is divided into a plurality of cuts in the cutout; Positioning an end of the FRP bar in the head mold so that the incision is positioned within the mold for the head made according to the shape of the block head; And forming a block head integrally with the end of the FRP bar by filling the end of the FRP bar with the cut-out part so that the concrete material is filled in the space of the cut-out part, Wherein the FRP reinforcing member is made of a metal.

In the method of the present invention, in the form member for a head, a spacing jig protruding in the direction of the final end face is provided on the longitudinal outer side wall facing the final end face of the FRP bar; When the end portion of the FRP bar is placed in the head mold, the gap holding jig can be fitted into the opening of the cut portion formed on the final end face of the FRP bar, so that the space of the cut portion to be filled with the concrete material can be maintained. In this case, the jig for holding the gap may be formed so as to protrude upward in a shape in which the sectional size becomes smaller as it protrudes from the longitudinal outer side wall.

Further, in the above-described method of the present invention, vertical open slots are formed in the inner side walls of the longitudinally opposite side walls of the head forming member from the vertical direction to the downward direction; In the step of positioning the end of the FRP bar in the head formwork, after the FRP bar is moved from the top to the bottom in the vertical direction and inserted into the vertical opening slot, the end portion of the FRP bar and the outer side wall So that the gap holding jig is fitted into the opening of the cut portion formed on the final end face of the FRP bar or the through wall is formed on the inner side wall of the longitudinal side walls of the form member for the head; In the step of positioning the end portion of the FRP bar in the head mold, the end portion of the FRP bar is inserted through the through hole of the inner side wall so that the final end surface of the FRP bar approaches the outer side wall, And can be inserted into the mouth of the incision formed in the final end face.

In particular, in the method of the present invention, the longitudinal length of the incision extending in the longitudinal direction starting from the final end face is determined by the diameter of the FRP bar, the number of incisions to be formed in the final end face of the FRP bar, , The FRP bar itself when tensile force is applied, using the values given in the design for each of the bond strength between the FRP bar and the FRP bar, the spacing of the cutout space, and the maximum draw load of the desired FRP stiffener in the design Calculating a maximum fracture load and a maximum pull load of the FRP bar itself which can withstand the fracture until it is cut; And calculating a maximum draw load of the FRP reinforcement from the maximum breakage load and the maximum attach load of the calculated FRP bar itself; And calculating the longitudinal length so that adhesion failure does not occur until the calculated maximum fracture load reaches the maximum pull load.

In order to achieve the above-mentioned object, the present invention also provides a method of manufacturing an FRP according to the above-described method, which comprises a bar-shaped FRP bar and a block head integrally provided at an end of the FRP bar so that the end of the FRP bar is embedded. A stiffener is provided.

In the present invention, an FRP reinforcement composed of an FRP bar and a block head integrally connected to an end of the FRP reinforcement is provided. In the FRP reinforcement of the present invention, the block head, which is embedded in the concrete structure and functions as an anchor body, Since the FRP reinforcement member is integrally provided on the FRP bar in the field, the overall cost required for fabricating the FRP reinforcement is much lower than that of the prior art, thereby providing excellent economical efficiency.

Particularly, in the FRP reinforcement of the present invention, since the block head is made of a concrete-based material, there is no problem in adhesion between the block head and the concrete structure due to heterogeneous materials in a state where the FRP reinforcement is embedded in the concrete structure And the block head is integrally attached to the concrete structure with ease at a time.

In the present invention, by forming the cut-out portion at the end of the FRP bar to be embedded in the block head, the area of the block head in which the concrete material and the FRP bar are brought into contact with each other is greatly increased. In the present invention, The effect of increasing the bonding area between the FRP bar and the concrete material for the block head can be exerted without increasing the FRP bar attachment length of the FRP bar. Therefore, according to the present invention, when the attachment length is the same, the FRP reinforcement of the present invention has a larger maximum draw load than that the FRP bar of a circular cross section is simply embedded in the block head, The FRP reinforcement of the present invention has a shorter attachment length than that of the FRP bar of the circular cross section and is embedded in the block head. The FRP reinforcement material can be easily buried and utilized.

1 is a schematic perspective view of an FRP reinforcement according to an embodiment of the present invention.
2 is a schematic perspective view of a FRP bar according to an embodiment of the present invention.
FIG. 3 is a schematic enlarged perspective view of the circle A portion of FIG. 2. FIG.
4 is a schematic perspective view showing a longitudinal final end face for a FRP bar according to another embodiment of the present invention.
5 is a schematic perspective view showing a process of installing a FRP bar on a die member for a head to manufacture the FRP reinforcement of the present invention.
Fig. 6 is a schematic perspective view showing the state after the FRP bar is installed on the form member for the head following Fig. 5;
FIG. 7 is a schematic perspective view showing a state in which a block head is formed by filling concrete form material into a head form member following FIG. 6; FIG.
8 is a schematic longitudinal side view of a FRP bar showing a final end face of a FRP bar according to an embodiment of the present invention.
FIG. 9 is a schematic enlarged perspective view of the circle B portion shown in FIG. 5; FIG.
10 is a schematic cross-sectional view along line CC of Fig.
11 is a schematic enlarged view of the circle D portion of Fig.
Fig. 12 is a schematic enlarged perspective view corresponding to Fig. 9 showing another embodiment of the present invention with respect to the gap holding jig.
Fig. 13 is a schematic enlarged view corresponding to Fig. 11 in the case where the gap keeping jig shown in Fig. 12 is applied.
Fig. 14 is a schematic enlarged perspective view corresponding to Fig. 9 showing a jig for holding a gap having a conical shape.
15 is a schematic perspective view showing a state in which a plurality of FRP stiffeners are manufactured simultaneously according to the present invention.
16 is a schematic perspective side view showing an example in which the FRP reinforcement of the present invention is embedded in a concrete girder.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Although the present invention has been described with reference to the embodiments shown in the drawings, it is to be understood that the technical idea of the present invention and its essential structure and operation are not limited thereby. In the present specification, the direction in which the FRP reinforcement extends is referred to as "longitudinal direction ", and the direction orthogonal to the longitudinal direction is referred to as" lateral direction ".

1 is a schematic perspective view of a FRP stiffener 100 according to an embodiment of the present invention. As illustrated in the figure, the FRP stiffener 100 according to the present invention includes a bar-shaped FRP bar 1, And a block head integrally provided at an end of the FRP bar in the form of a block made of a concrete material such as concrete or mortar and having an end of the FRP bar embedded in a concrete material, (2). In the present invention, however, the end portion of the FRP bar 1 is not simply embedded in the block head 2 in a circular section, but is embedded in the structure described below.

2 is a schematic perspective view of a FRP bar 1 according to an embodiment of the present invention. FIG. 3 is a schematic perspective view showing a longitudinal end end face of the FRP bar 1 shown in FIG. , A schematic enlarged perspective view of the circle A portion of Fig. 2 is shown. 2 and 3, in the case of the FRP bar 1 constituting the FRP reinforcement 100 of the present invention, the FRP bar 1 is cut into a plurality of branches at an end portion of the block head 2, A cut-out portion 10 is formed. The incision 10 is formed such that when the final end face 11 of the FRP bar 1 is viewed in the longitudinal direction, the plane having the length of the radius of the FRP bar 1 at the center of the circle of the final end face 11, In which the FRP bars 1 are cut. The cutout portion 10 may be formed using a grinder, a water jet, or the like. In the case of the embodiment illustrated in FIGS. 2 and 3, when four cutouts 10 are present in a cross (+) shape and the final end face 11 of the FRP bar 1 is viewed in the longitudinal direction, The FRP bar 1 is cut so that the final end face 11 is composed of four branches, that is, a quadrant.

Fig. 4 is an enlarged perspective view corresponding to Fig. 3 showing a longitudinal final end face of the FRP bar 1 according to another embodiment of the present invention. In the case of the FRP bar 1 shown in Fig. 4, A plurality of slits 10 are formed in the same manner as the FRP bar 1 shown in FIG. 2. In addition, a concave portion 12 is formed at the center of the final end face 11 in the longitudinal direction have. When the FRP stiffener 100 of the present invention is manufactured, the gap holding jig 22 for maintaining the space between the cutouts 10, that is, the interval between the cut branches of the FRP bar 1, When the recessed portion 12 is formed at the center of the final end face 11 as described above, the gap holding jig 22 is easily inserted into the incision portion 10 formed in the end face 11, (10).

In the case of the embodiment shown in Figs. 2 and 4, the end portion of the FRP bar 1 is divided into four quadrants by four cutouts 10 and cut. That is, since the incision corresponds to the radius of the circular cross section of the FRP bar 1 in the longitudinal cross section of the FRP 1, four incisions 10 are present in the embodiment shown in FIGS. 2 and 4 And the cross section of the FRP bar 1 in the longitudinal direction is divided into four sections and cut.

However, in the present invention, the number of cut-out portions 10 is not limited thereto. That is, the end of the FRP bar 1 may be divided into three sections by the three sections, and the number of the sections may be five or more, so that the end of the FRP bar 1 is divided into sections .

In the present invention, the cutout portion 10 starts from the final end face 11 of the FRP bar 1 and is formed to extend in the longitudinal direction in a section shorter than the longitudinal length of the block head 2. That is, the FRP bar 1 is formed such that a plurality of cutouts 10 are formed at the end of the FRP bar 1 from the final end face 11 of the FRP bar 1 to the longitudinal length of the block head 2, 1) is produced.

Next, a process of fabricating the FRP reinforcement 100 of the present invention using the FRP bar 1 having the cut-out portion 10 formed at the end will be described.

5 is a schematic perspective view showing a process of installing a FRP bar 1 on a head forming member 20 in order to manufacture the FRP reinforcement 100 of the present invention. FIG. 7 is a schematic perspective view showing a state after the FRP bar 1 is installed on the form member 20 for a head. FIG. 7 shows a schematic perspective view of the FRP bar 1 with the cut- There is shown a schematic perspective view showing a state in which the block member 2 is formed by filling concrete form material into the head form member 20 so that the end portions are all buried.

5 to 7, the end portion of the FRP bar 1 manufactured to form the cut-out portion 10 is positioned in the head forming member 20 manufactured according to the shape of the block head 2 The head molding member 20 is filled with a flowable concrete material such as mortar or concrete so as to be buried so that the incision portion 10 is embedded in the FRP bar 1, So that the FRP reinforcement 100 is manufactured so that the block head 2 is formed. The concrete material constituting the block head 2 is a ultra high performance concrete called UHPC (Ultra High Performance Concrete), but is not limited thereto.

In positioning the end portion of the FRP bar 1 in the form member 20 for a head, as shown in the figure, the inner side wall 23 of the longitudinally opposite side walls of the head forming member 20 So that the ends of the FRP bars 1 are positioned in the head forming member 20 by moving the FRP bars 1 in the vertical direction from the top to the bottom and inserting them into the vertical open slots 230, The end end face 11 of the FRP bar 1 may be made to approach the outer side wall 21 but only the through hole may be formed in the inner side wall 23 and the end of the FRP bar 1 may be passed through the through hole, (20).

If the FRP bar 1 is installed in the form member 20 for the head and the concrete material of the fluidity is laid on the form member 20 for the head in a state where the FRP bar 1 is positioned so that the cut- The concrete material is filled in the space formed by the cutout 10, as well. That is, the concrete-based material is attached not only to the outer surface of the FRP bar 1 but also to the cut-away surface of the FRP bar 1 exposed to the gap between the columns of the FRP bar 1 made by the cut- .

In manufacturing the FRP reinforcement 100 of the present invention in which the block head 2 is coupled to the end of the FRP bar 1, when the tensile load is applied to the FRP bar 1, the FRP bar 1 itself is broken It is most preferable that the FRP bar 1 is prevented from escaping from the block head 2 until the maximum load of the FRP bar that can withstand the breaking, that is, the maximum breaking load Pf of the FRP bar is reached. In order to make these optimal conditions, FRP bar (1) that is the maximum load that prevents, tug from the block head 2, the maximum adhesion force (P s), the FRP bar such that the maximum breaking load than (P f) of the FRP bar The length of the end portion of the block 1 coupled with the block head 2, that is, the length of attachment between the FRP bar 1 and the block head 2, may be increased. However, when the diameter of the FRP bar is large, the length of the attachment increases. The large length of the block head 2 means that the longitudinal length of the block head 2 is large. Since the FRP reinforcement is embedded in the concrete member, if the longitudinal length of the block head 2 is large, It becomes difficult to be buried and used so that there is a problem that it is not worth using in reality.

As described above, in the present invention, the end portion of the FRP bar 1 is not simply buried in the block head 2 as a circular cross section, but the cut portion 10 is formed in the longitudinal direction at the end portion of the FRP bar 1 And is embedded in the block head 2 in a state of being formed by the length. When the cut-out portion 10 is formed, a cut-away surface for contacting the FRP bar 1 with the concrete-based material is newly present in the gap of the cut-out portion 10, The joint area between the FRP bar 1 and the concrete-based material is greater than the joint area between the FRP bar 1 and the FRP bar 1 due to the flow of the concrete-based material into the space of the incision 10, Is added and greatly increased. That is, in the present invention, it is possible to increase the bonding area between the FRP bar 1 and the concrete material for the block head 2 without increasing the length of the FRP bars 1 in the longitudinal direction. Therefore, if the attachment length is the same, the draw load, that is, the maximum draw load that the FRP reinforcement 100 of the present invention can withstand is larger than the case where the FRP bar 1 having a circular cross section is simply embedded in the block head 2 The FRP stiffener 100 of the present invention has a shorter attachment length than the FRP bar 1 having a circular cross section in the block head 2 The longitudinal length in which the end of the block head is embedded in the block head).

In the FRP reinforcement 100 of the present invention, the attachment length at which the end of the FRP bar 1 is embedded in the block head 2 is determined by the longitudinal length L of the cutout formed at the end of the FRP bar 1, The length of the incision part from the final end face 11 of the FRP bar 1 may be equal to or longer than the length of the incision part from the final end face 11 of the FRP bar 1. In the present invention, the minimum value of the longitudinal length L of the incision part is calculated, The longitudinal length L of the incision portion is determined.

Figure 8 shows a schematic longitudinal side view of a FRP bar showing the final end face 11 of the FRP bar. As shown in Fig. 8, the diameter of the FRP bar 1 is D, the thickness at which the cross section is lost by the cut section 10, that is, the interval between the cut portions 10, is t and the final end face 11 The sectional area A of the FRP bar 1 with respect to the longitudinal cross section in the section where the cutout section 10 is formed is represented by the following equation 1 and the FRP bars 1, 1 is the following equation (2): " (2) "

Figure 112016020568507-pat00001

Figure 112016020568507-pat00002

In the above equations (1) and (2),? Is the circularity.

Therefore, when the tensile strength of the FRP bar 1 and the FRP bar 1 is f and the adhesion strength between the block heads 2 to be embedded with the FRP bars 1 is τ, the FRP bars 1 themselves are broken The maximum breaking load P f of the FRP bar 1 itself is as shown in the following Equation 3 and the tensile load that can withstand the cutting is not separated between the FRP bar 1 and the block head 2 tensile load capable of withstanding the maximum in the bonded state, i.e., the maximum adhesion force (P s) is equal to the expression (4) below. Here, the tensile strength f and the bond strength τ are determined through experimentation as material-specific properties.

Figure 112016020568507-pat00003

Figure 112016020568507-pat00004

Therefore, FRP bar (1) to the maximum by the block head 2, the maximum pull-out load P u in the end up breaking load by Equation 3 P f and the equation (4) that can be applied to FRP stiffener 100 of the present invention consisting of Is smaller than the attached load P s . That is, the maximum pullout load P u is calculated by the following equation (5).

Figure 112016020568507-pat00005

The diameter D of the FRP bar 1, the number n of the cutouts 10 to be formed on the final end face 11 of the FRP bar, the tensile strength f of the FRP bar 1, Given the values of the adhesion strength τ between the block head 2 and the FRP bar 1, the spacing t of the space of the cutout 10 and the maximum fracture load P u of the desired FRP stiffener 100 in the design, The maximum fracture load P f is calculated by Equation (3).

If the value of the calculated maximum fracture load P f is less than the value of P u , the FRP stiffener 100 will eventually fracture and fracture before the desired tensile load is applied in the design, Replace with another one. A new FRP bar having the diameter D of the new FRP bar 1, the number n of the cutouts 10 to be formed on the final end face 11 of the FRP bar or the tensile strength f value of the FRP bar 1 is again selected, It is necessary to calculate the maximum fracture load P f by Equation (3) and to perform the above operation in which it is compared with the maximum fracture load P u of the desired FRP stiffener 100 in the design.

That is, until the <maximum breaking load P f value is more than the value of P u of> bar FRP which can satisfy the condition of selection of the diameter of the new FRP bar (1) D, the final end surface (11 of the FRP bar &Lt; calculation of the maximum fracture load P f and contrast work with the maximum fracture load P u > for a new FRP bar in which the number n of cutouts 10 to be formed in the FRP bar 1 or the tensile strength f value of the FRP bar 1 are different will be.

In the condition that <maximum breaking load P value of f is more than the value of P u> nominal state, FRP bar 1 and the block head to reach the maximum pull-out load of the FRP reinforcing material (P u) (2 Is not destroyed. That is, the maximum attached load (P s ) has a value greater than the maximum pull load (P u ) of the FRP bar. Mathematically, this is expressed by the following equations (6) and (7).

Figure 112016020568507-pat00006

Figure 112016020568507-pat00007

Therefore, the FRP bar 1 having the diameter D, the number n of the cutouts 10, and the tensile strength f value, which makes it possible to satisfy the condition that the value of the maximum breaking load P f is equal to or greater than the value of P u After the selection, the diameter D of the FRP bar 1, the number n of the cutouts 10, the tensile strength f, the spacing t of the space of the cutout 10, and the distance between the block head 2 and the FRP bars 1), the longitudinal length L of the incision portion is calculated by substituting the equations (3), (4) and (7) into the minimum longitudinal length L of the incision portion, Or more.

5 to 7, in forming the block head 2 by disposing the end portion of the FRP bar 1 in the head forming member 20, the concrete structure filled in the head forming member 20 It is very important that the material flows into the space of the incision 10 and is filled. That is, it is necessary that the space of the incision part 10 is continuously maintained in the process of filling the concrete form material into the molding part 20 for the head. In order to achieve this, in the present invention, The jig 22 can be used.

Fig. 9 is a schematic enlarged perspective view of the circle B portion shown in Fig. 5, and Fig. 10 is a schematic cross-sectional view along the line CC of Fig. 7, A schematic enlarged view is shown. As illustrated in the figure, the longitudinal outer sidewall 21 facing the final end face 11 of the FRP bar 1 in the form member 20 for the head is protruded in the direction of the final end face 11, 1 is provided with a gap holding jig 22 to be fitted in the mouth of the cutout 10 formed on the final end face 11 of the base plate 1.

Therefore, in order to manufacture the FRP reinforcement 100 of the present invention, the final end face 11 of the FRP bar 1 is inserted into the spacing jig (not shown) while positioning the end of the FRP bar 1 in the head- The gap holding jig 22 protruding from the longitudinal outer sidewall 21 is pushed in the direction of the longitudinal outer sidewall 21 of the FRP bar 1, (11) to the incision (10). That is, the gap holding jig 22 is inserted into the space of the cutout portion 10. As described above, in the state where the gap holding jig 22 is fitted in the cutout portion 10 on the final end face 11 of the FRP bar 1, even if a pressing force is applied to the end portion of the FRP bar in the lateral direction , The spacing between the branches at the final cross section of the FRP bar 1 made by the cutout 10 is not narrowed and the original spacing is constantly maintained by the spacer jig 22. [ Accordingly, as described above, the concrete material flows smoothly into the space of the cut-out portion 10 during the process of filling the concrete material into the head forming member 20, ) And the concrete material for the block head (2) can be more stably guaranteed.

Particularly, in the present invention, since the interval holding jig 22 is previously provided on the longitudinal outer side wall 21, the final end face 11 of the FRP bar 1 is connected to the end The spacing jig 22 is easily inserted into the space of the cutout 10 by simply pushing the FRP stiffener 100 in the direction of the outer side wall 21 so that the FRP stiffener 100 can be manufactured easily and quickly There is an advantage that can be.

1 to 10, since the end portion of the FRP bar 1 is cut into four quadrants, the entrance of the cutout portion 10 formed on the final end face 11 of the FRP bar 1 is made of The jig 22 is formed in a cross shape when viewed in the longitudinal direction, as shown in Fig.

However, the shape of the gap holding jig 22 is not limited to that shown in Fig. 12 is a schematic enlarged perspective view of the circle A portion of Fig. 5 corresponding to Fig. 9 showing another embodiment of the gap keeping jig 22, and Fig. 13 is a schematic enlarged perspective view of the gap holding jig 22 shown in Fig. There is shown a schematic enlarged view of the circle D portion of Fig. 10 corresponding to Fig. 11 for the case where the jig 22 is applied.

12 and 13, when forming the cross-holding jig 22 in the shape of a cross, the interval maintaining jig (22) is formed in such a shape that the sectional size of the cross-shaped jig becomes larger as it protrudes from the longitudinal outer side wall 22 may be protruded so as to taper upwardly. In this case, since the gap holding jig 22 having a small cross section enters the mouth of the cutout 10, the gap holding jig 22 is formed on the final end face 11 of the FRP bar 1 The operation of fitting into the mouth of the incision 10 is greatly facilitated and if necessary the incision 10 is further widened in accordance with the degree of approaching the FRP bar 1 close to the longitudinal outer sidewall 21 It can also keep space.

Further, the gap holding jig 22 is not limited to the cross shape as shown above. Fig. 14 shows a schematic perspective view corresponding to Fig. 9 showing another shape of the gap keeping jig 22, which is shown in Fig. 14 in the direction of the final end face 11 of the FRP bar 1 The jig 22 for holding the gap may be formed in a tapered conical shape in which the cross section of the jig 22 is reduced while being tapered, or may have another conical shape or another shape.

4, when the concave portion 12 is formed at the center of the final end face 11, the gap holding jig 22 made of a conical shape or a simple rod shape as shown in Fig. The effect of being inserted into the recessed portion 12 can be more easily achieved.

On the other hand, when the block head 2 is integrally joined to the end portion of the FRP bar 1 by using the head forming member 20 as described above, a plurality of head forming members 20 are continuously arranged A plurality of FRP stiffeners 100 may be manufactured at the same time by arranging the ends of the FRP bars 1. [ FIG. 15 is a schematic perspective view showing a state in which a plurality of FRP stiffeners 100 are manufactured at the same time. In FIG. 15, the concrete-based material is not yet laid in the head forming member 20.

As described above, the gap-holding jig 22 is inserted into the mouth of the incision 10, so that the concrete-based material flows smoothly into the gap of the incision 10 in a state where the gap of the incision 10 is maintained, The FRP bar 1 and the block head 2 are firmly integrated with each other with the joint area increased, thereby manufacturing the FRP reinforcement 100 of the present invention. That is, the FRP reinforcement 100 is manufactured by firmly and integrally providing the block head 2 having a required cross-sectional shape and cross-sectional size, which is a low cost concrete material, on the FRP bar 1. Special

16 is a schematic perspective side view showing an example in which the FRP stiffener 100 of the present invention is embedded in the concrete girder 200. As illustrated in FIG. 16, the FRP stiffener 100 of the present invention, Is embedded in a portion of a concrete structure such as a concrete bottom plate, a concrete girder, etc. where tensile force acts. Since the FRP reinforcement 100 of the present invention is made of a concrete material which is embedded in a concrete structure and acts on a tensile force, that is, a block head 2 corresponding to a part functioning as an anchor body, which is a material similar to a concrete structure, The FRP reinforcement 100 of the present invention exhibits the advantage that the block head 2 and the concrete structure are easily bonded together without any problem due to heterogeneous materials when they are embedded in the concrete structure.

Above all, since the FRP reinforcement 100 of the present invention can be integrally provided with FRP bars in the field by using a low-cost concrete-based material, the cost for manufacturing the FRP reinforcement 100 is much lower than that of the prior art , And thus has an advantage in that it has excellent economical efficiency.

In the above description of the present invention, only the block head 2 is provided on one side of the longitudinal direction of the FRP bar 1, but the FRP reinforcement 100 of the present invention is provided on both longitudinal sides of the FRP bar 1 As a further embodiment, the block head 2 is provided.

1: FRP bar
2: Block head
10: incision
11: final end face
12:
20: Form member for head
22: Jig for keeping spacing

Claims (8)

delete A method of manufacturing an FRP reinforcement comprising a bar-shaped FRP bar (1) and a block head (2) integrally provided at an end of the FRP bar (1) so that the end of the FRP bar (1)
A plurality of cutouts 10 extending in the longitudinal direction starting from the final end face 11 are formed at the end of the FRP bar 1 to be embedded in the block head 2, Cutting the end of the FRP bar (1) so that the cutter (11) is divided into a plurality of branches at the cutout (10);
Positioning an end of the FRP bar 1 on the head mold 20 so that the cutout 10 is located in the head mold member 20 made to conform to the shape of the block head 2; And
The FRP bar 1 is filled with the concrete material in the head forming member 20 so that the end portion of the FRP bar 1 formed with the cutout portion 10 is embedded and the concrete material is filled in the space of the cutout portion 10, And forming the block head (2) so as to be integral with the end of the block head (2);
In the head molding member 20, a gap holding jig 22 protruding in the direction of the final end face 11 is formed on the longitudinal outer side wall 21 facing the final end face 11 of the FRP bar 1 Install;
When the end portion of the FRP bar 1 is placed in the head mold 20, the gap holding jig 22 is inserted into the mouth of the cutout portion 10 formed on the final end face 11 of the FRP bar 1 So that the space of the cutout (10) to be filled with the concrete-based material is maintained.
3. The method of claim 2,
Wherein the gap holding jig (22) is protruded and formed in a shape tapering upward in such a manner that the cross sectional size of the jig (22) becomes smaller as it is projected from the longitudinal outer side wall (21).
The method according to claim 2 or 3,
A vertical open hole 230 is formed in the inner side wall 23 of the sidewalls of the head forming member 20 from the vertical direction to the vertical side;
In the step of positioning the end portion of the FRP bar 1 in the head formwork 20, the FRP bar 1 is inserted into the vertical open hole 230 by moving it from the top to the bottom in the vertical direction, The distance maintaining jig 22 is formed on the final end face 11 of the FRP bar 1 so that the final end face 11 and the outer side wall 21 of the FRP bar 1 approach each other. So as to be fitted into the opening of the incision part (10).
The method according to claim 2 or 3,
A through hole is formed in the inner sidewall 23 of the sidewalls of the head forming member 20 in the longitudinal direction;
The end portion of the FRP bar 1 is inserted into the through hole of the inner side wall 23 to insert the end portion of the FRP bar 1 into the end mold surface 20 11 allows the gap holding jig 22 to be fitted into the mouth of the cutout 10 formed on the final end face 11 of the FRP bar 1 by making the gap holding jig 22 approach the outer side wall 21 Method of making FRP reinforcement.
The method according to claim 2 or 3,
In determining the longitudinal length L of the incision 10 extending in the longitudinal direction starting from the final end face 11,
The diameter D of the FRP bar 1, the number n of the cutouts 10 to be formed on the final end face 11 of the FRP bar, the tensile strength f of the FRP bar 1, The adhesion strength τ between the FRP bar 2 and the FRP bar 1, the spacing t of the space of the cutout 10 and the maximum drawing load P u of the desired FRP stiffener 100 in the design, Calculating a maximum fracture load (P f ) of the FRP bar (1) itself which can withstand the fracture of the FRP bar (1) itself when the tensile force acts on the FRP bar (1) by the following equation (3);
Comparing the maximum fracture load (P f ) of the calculated FRP bar (1) itself with the maximum fracture load (P u ) of a desired FRP stiffener (100) in design; And
If the calculated maximum fracture load P f is less than the maximum fracture load P u of the desired FRP stiffener 100 in the design, the diameter D of the new new FRP bar 1, the final end face 11 of the FRP bar, A new FRP bar having a number n of cut-out portions 10 to be formed in the FRP bar 1 or a tensile strength f value of the FRP bar 1 is selected again, and the maximum fracture load Pf is calculated according to Equation (3) If, and compared to the maximum breaking load P u of 100, to correspond to more than the maximum breaking load (P f), the maximum breaking load (P u) of the FRP reinforcing material (100) from the design output, the FRP bar (1 The number n of the cutouts 10, the tensile strength f, the spacing t of the space of the cutout 10 and the value of the adhesion strength? Between the block head 2 and the FRP bar 1 are used And calculating the minimum value of the longitudinal length (L) of the incision part by substituting into the equations (3), (4) and (7) The manufacturing method of the FRP reinforcing material characterized in that it comprises the step of determining the length direction (L) equal to or greater than the calculated minimum value.
(3)
Figure 112016056349299-pat00027

(4)
Figure 112016056349299-pat00028

(7)
Figure 112016056349299-pat00029

(Where, in the equations (3) and (4),? Is the circumferential ratio, A is the cross-sectional area of the FRP bar with respect to the longitudinal section, and u is the circumference of the longitudinal section of the FRP bar)
A rod-shaped FRP bar 1 and a block head 2 integrally provided at an end of the FRP bar 1 so that the end of the FRP bar 1 is embedded;
The end of the FRP bar 1 to be embedded in the block head 2 is cut into a plurality of branches by the cutout 10;
The cut portion 10 is previously embedded in the block head 2 in a state where the cut portion 10 is formed on the end portion of the FRP bar 1 so that the material forming the block head 2 is filled in the space formed by the cut portion 10 Wherein the block head (2) is provided on the FRP bar (1).
delete
KR1020160025397A 2016-03-03 2016-03-03 FRP Bar having Head, and Manufacturing Method thereof KR101644331B1 (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101768534B1 (en) * 2017-01-17 2017-08-16 (주)엔비건설 Reinforcing Steel Anchor for Enlargement Structure, the Manufacturing Methods and the Construction Method thereof
KR20180102757A (en) * 2017-03-08 2018-09-18 충남대학교산학협력단 Pull-out test specimen, Method for manufacturing specimen, and Pull-out tester

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09207117A (en) * 1996-01-31 1997-08-12 Nippon Steel Corp Metal fitting and method for fixing terminal of frp reinforcing material
JP2933959B2 (en) * 1989-12-14 1999-08-16 株式会社熊谷組 Anchoring structure of fiber reinforced synthetic resin concrete reinforcing rod
KR20100049195A (en) 2008-11-03 2010-05-12 고려대학교 산학협력단 A frp reinforcing with head and manufactured thereof
KR20100069839A (en) * 2008-12-17 2010-06-25 재단법인 포항산업과학연구원 Precast anchorage block and prestressed concrete member with the same
KR20130076088A (en) * 2011-12-28 2013-07-08 한밭대학교 산학협력단 Mechanical anchorage for reinfoece member made from fiber reinforced polymer

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2933959B2 (en) * 1989-12-14 1999-08-16 株式会社熊谷組 Anchoring structure of fiber reinforced synthetic resin concrete reinforcing rod
JPH09207117A (en) * 1996-01-31 1997-08-12 Nippon Steel Corp Metal fitting and method for fixing terminal of frp reinforcing material
KR20100049195A (en) 2008-11-03 2010-05-12 고려대학교 산학협력단 A frp reinforcing with head and manufactured thereof
KR20100069839A (en) * 2008-12-17 2010-06-25 재단법인 포항산업과학연구원 Precast anchorage block and prestressed concrete member with the same
KR20130076088A (en) * 2011-12-28 2013-07-08 한밭대학교 산학협력단 Mechanical anchorage for reinfoece member made from fiber reinforced polymer

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101768534B1 (en) * 2017-01-17 2017-08-16 (주)엔비건설 Reinforcing Steel Anchor for Enlargement Structure, the Manufacturing Methods and the Construction Method thereof
KR20180102757A (en) * 2017-03-08 2018-09-18 충남대학교산학협력단 Pull-out test specimen, Method for manufacturing specimen, and Pull-out tester
KR101990589B1 (en) * 2017-03-08 2019-09-30 충남대학교 산학협력단 Pull-out test specimen, Method for manufacturing specimen, and Pull-out tester

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