KR100857930B1 - Reinforcing rod, reinforcing rod coupler and coupling method thereby - Google Patents

Abstract

A reinforcing bar and a reinforcing bar coupler, and a coupling method of reinforcing bars are provided to manufacture simply, to economize in materials and to improve adhesive property and stiffness without directional deflection, and to couple reinforcing bars conveniently without additional work at a construction site or a production site. A reinforcing bar(20) is formed to have an equilateral triangle shape of a rounded cross section by twisting steel(21) having a rib(22) projected outward from the center of each side of a triangle like a screw in the longitudinal direction, and screw shaped leads are regular in the longitudinal direction of the reinforcing bar, and more than three times as thick as the diameter of the reinforcing, so that threads are formed at an inclination of 45 degrees or more. A reinforcing bar coupler(30) is formed to have a hollow equilateral triangle shape of a rounded cross section by twisting a piped member(31) having a rib housing(32) projected outward from the center of each side of a triangle like a screw in the longitudinal direction, wherein screw shaped leads are regular in the longitudinal direction of the reinforcing bar, and more than three times as thick as the diameter of the reinforcing bar coupler and corresponds to leads of the reinforcing bar, so that threads are formed at an inclination of 45 degrees or more. The steel and the rib of the reinforcing bar are placed and coupled in the piped member and the rib housing of the reinforcing bar coupler in the longitudinal direction by making one revolution.

Description

Rebar and rebar coupler and rebar connection method using them {REINFORCING ROD, REINFORCING ROD COUPLER AND COUPLING METHOD THEREBY}

1 is a perspective view of a conventional release rebar;

2 is a side view of a conventional release rebar;

3 is a cross-sectional view of a conventional release rebar;

4 is a perspective view of a reinforcing bar as a first embodiment according to the present invention;

5 is a side view of a reinforcing bar as a first embodiment according to the present invention;

6 is a cross-sectional view of a reinforcing bar as a first embodiment according to the present invention;

7 is a perspective view of a rebar coupler as a first embodiment according to the present invention;

8 is a side view of a rebar coupler as a first embodiment according to the present invention;

9 is a sectional view of a rebar coupler as a first embodiment according to the present invention;

FIG. 10 is a perspective view of an example of coupling using the rebar of FIG. 4 and the rebar coupler of FIG. 7; FIG.

FIG. 11 is a sectional view of the coupling portion of FIG. 10; FIG.

12 is a perspective view of a reinforcing bar as a second embodiment according to the present invention;

13 is a side view of a reinforcing bar as a second embodiment according to the present invention;

14 is a sectional view of a reinforcing bar as a second embodiment according to the present invention;

15 is a perspective view of a rebar coupler as a second embodiment according to the present invention;

16 is a side view of a rebar coupler as a second embodiment according to the present invention;

17 is a cross-sectional view of a rebar coupler as a second embodiment according to the present invention;

18 is a perspective view of an example of coupling using the deformed rebar of FIG. 12 and the rebar coupler of FIG. 15;

19 is a sectional view of the coupling portion of FIG. 18;

20 is a perspective view of a reinforcing bar coupler having an opening at a side thereof;

21 is a perspective view and a cross-sectional view showing a state in which a plurality of reinforcing bar couplers are coupled to each other and rebars of different diameters are coupled to both sides thereof;

22 is a perspective view and a cross-sectional view illustrating a state in which two rebars are connected by overlapping a plurality of rebar couplers; And,

Fig. 23 shows modifications of the reinforcing bar and the reinforcing bar coupler of the first and second embodiments.

<Description of Symbols for Main Parts of Drawings>

10, 20, 20a, 20 ', 40, 40': deformed rebar

11, 21, 21 ', 41, 41': Steel

12. 22, 22 ', 42, 42': Rib

13: node

30, 30a, 30 ', 50, 50': rebar coupler

31, 31 ', 51, 51': tubular member

32, 32 ', 52, 52': rib receiving part

33: opening

34: injection hole

The present invention forms a cross-sectional shape of the reinforcing steel in a rounded regular triangle or square and twisted it like a screw along the longitudinal direction, and the reinforcing coupler is also formed by the hollow rounded regular triangle or square of the tubular member, the production is simple, The present invention relates to a reinforcing bar and rebar coupler that greatly improves adhesion and stiffness while reducing the amount of material without any variation in direction, and makes reinforcing bar work very convenient without any separate work in the field.

Reinforcing bars are embedded in concrete for the purpose of reinforcing relatively weak tensile stress compared to compressive stress in concrete structures. Rebar should have good adhesion to concrete, have high strength and yield point, ductility, easy processing, high corrosion resistance, and easy jointing. Most of this is solved by thickening the rebar, but vaguely thickening the rebar is a waste of material and should be avoided at this point, especially when raw material prices are rising.

The yield point, ductility, and resistance to corrosion among the requirements of the reinforcing bar depend on the material of the rebar itself or the properties of the material. something to do. The cross-sectional shape of the reinforcing bars is also closely related to the amount of material used.

Reinforcing bars are divided into smooth reinforcing bars and artificially shaped deformed bars.The reinforcing bars have a smooth surface with no projections on the surface of steel. .

Deformed steel rebar has irregularities such as ribs and nodes on the surface of the steel, and has great advantages in adhesion and sliding resistance.

1 to 3 are a perspective view, a side view, and a sectional view of a conventional deformed steel bar. In general, the conventional release reinforcing bar 10 has a shape in which the ribs 12 protrude symmetrically along the longitudinal direction of the bar 11 and the nodes 13 are formed at regular intervals in the longitudinal direction.

The deformed reinforcing bar 10 has a cross section as shown in FIG. 3, which has a large moment of inertia about the y-axis while a small moment of inertia about the x-axis is small, depending on how the rebar is placed. There was a problem that a deviation occurs in the bending rigidity.

On the other hand, because the nodes 13 are spaced along the lengthwise direction, the nodes 13 are only involved in improving adhesion with concrete, but do not help in improving the bending rigidity of the reinforcing bars.

Therefore, this conventional deformed reinforcing bar 10 can not be seen that the effective utilization of the material.

On the other hand, in order to connect the reinforcing bars in the longitudinal direction has been used a method of overlapping joints, mechanical joints (screw joints, filling joints, compression joints), welded joints. The negative overlapping method has the problem that the rebar is wasted as much as the overlapping length. Threaded joints also had the hassle of screwing the end of the reinforcing bar when joining, and there was a problem that a lot of time and time was spent in the field of jointing and welding joints.

Therefore, the present invention is to solve the conventional problems as described above, the production is simple, greatly improves the adhesion and rigidity while reducing the amount of material without variation in the direction, separate work in the construction site or production site It is an object of the present invention to provide a reinforcing bar and a reinforcing bar coupler so that rebar joint work can be made very conveniently.

In order to achieve the above object, the present invention provides a reinforcing bar formed by twisting a steel material having a round or triangular cross section in the form of a screw with a predetermined lead along a longitudinal direction. The triangular or rectangular cross section has a greater moment of inertia than the cross section of a circle, so that it has a greater rigidity when the same amount of material is used. In addition, the deflection of the bending stiffness according to the direction to offset, especially if it is constantly twisted with a predetermined lead it is very convenient to be able to simply connect the rebar and the reinforcing bar only with a rebar coupler to be described later without additional work.

Here, it is preferable that the ribs protrude along the longitudinal direction of the steel in the center portion of each side of the triangular or square shape of the steel. These ribs increase the adhesion to concrete and are located in the center of each side, thus reinforcing the flexural stiffness in the bending direction, which may be relatively weak in terms of moment of inertia.

The lead is preferably at least three times the reinforcing bar diameter. This is because when the lead is π times the diameter, the inclination of the thread is 45 °, so that the lead is at least three times the diameter of the reinforcing bar and the inclination of the thread is at least 45 °. This eliminates the inconvenience of having to return either bar tens or tens of times when connecting. Since concrete is attached to reinforcing bars in a triangle or square shape, there is no fear that the reinforcing bars will rotate and be separated from each other.

In another aspect, the present invention provides a reinforcing bar coupler formed by twisting a hollow tubular member having a rounded triangular or rectangular cross section in the form of a screw with a predetermined lead along a longitudinal direction. This is for use in the connection of the reinforcing bar, the present invention is because the outer surface of the coupler as a connecting member is also a twisted shape in the form of a triangle or square screwed in the coupler will have the adhesive force with the concrete. In addition, since the hollow tubular cross section has a large moment of inertia, there is no problem in the rigidity of the reinforcing structure without the need for a large amount of material.

Here, it is preferable that the rib receiving portion protrudes outwardly along the longitudinal direction of the tubular member to accommodate ribs of the reinforcing bar at the center of each side of the triangular or square shape of the tubular member.

The lead is preferably at least three times the diameter of the rebar coupler.

Of course, the lead of the rebar and the rebar coupler coincide.

An opening for confirming the insertion depth of the rebar may be formed at a side near the center in the longitudinal direction of the rebar coupler. These openings can verify the rebar connection by checking the reinforcement depth of the reinforcement, and also allow concrete to flow through the openings so that the concrete and the reinforcing bars are firmly attached. In addition, by forming an injection hole in the other side near the center of the rebar coupler and injecting epoxy, rebars disposed in the two rebar couplers can be firmly fixed.

In addition, provided with a couple of reinforcing bar coupler having a different diameter, so that the rebar coupler can be coupled to the outside of one rebar coupler may be connected to the reinforcing bars of different diameters.

In addition, the present invention, the two reinforcing rods twisted in the form of a screw with a predetermined lead along the longitudinal direction of the round or triangular shaped steel, and the hollow tubular member having a rounded triangular or rectangular cross section in length A rebar coupler twisted in the form of a screw with a predetermined lead same as the rebar along the direction, and each end of the two reinforcing bars to be connected are screwed to both ends of the rebar coupler in a screw direction. This maintains the strength of the reinforcing bars and rebar couplers, while allowing simple connections between the two bars at the site or in the production phase without any additional assembly process.

Here, when connecting the ends of the two reinforcing bars, the lead overlaps a plurality of reinforcing bar couplers having the same diameter and different diameters and may further reinforce the reinforcing bar coupler portion.

In addition, with respect to the reinforcing bar coupler, a smaller diameter reinforcing bar is connected to one side of the rebar coupler having a smaller diameter, and a larger diameter reinforcing bar is connected to the other side of the larger reinforcing coupler. Can be connected.

Hereinafter, a first embodiment of a rebar and a rebar coupler according to the present invention will be described in detail with reference to the accompanying drawings.

4 to 6 are a perspective view, a side view, and a sectional view of a reinforcing bar as a first embodiment according to the present invention.

Reinforcing bar 20 according to the present invention is formed by twisting like a screw in the longitudinal direction of the steel 21 in the shape of a regular rounded cross-sectional cross-section and the rib 22 protrudes outward in the vicinity of the center of each side of the triangle will be. At this time, all of the threaded leads are constant in the longitudinal direction of the reinforcing bar 20 and are three times or more the diameter (thickness) of the reinforcing bar 20. Therefore, the screw shape is made so that the inclination is 45 ° or more, it can be seen that the slope of the screw shape is very steep as shown in the figure.

Since the equilateral triangle shape having a substantially rounded cross section is a shape that can be simply produced by roller molding or extrusion molding, manufacturing is very simple.

Steels with an equilateral triangle have superior bending (bending) stiffness because they use the same amount of material, that is, they have a larger moment of inertia than steels of circular cross-section having the same area. Therefore, the material can be reduced.

In addition, by twisting the shape of the equilateral triangle in the form of a bend on the side surface of the reinforcing bar 20, which increases the adhesion to the concrete. And because the cross-section is rotated in the form of a screw along the longitudinal direction to offset the deviation of the bending stiffness along the direction.

In particular, if it is regularly twisted with a predetermined lead, it is possible to simply connect the rebar 20 and the rebar 20 with only the rebar coupler 30 to be described later without additional work.

Since the rib 22 increases adhesion with concrete and is located at the center of each side, the rib 22 reinforces the bending rigidity with respect to the bending direction that may be weak in terms of the moment of inertia in the cross section of the triangle.

In this case, when the lead is π times the diameter, the inclination of the thread is 45 °, so that the lead is at least three times the diameter of the reinforcing bar 20 so that the inclination of the thread is at least 45 °, as in the conventional female screw coupling method. When connecting the two reinforcing bar 20 is to remove the inconvenience of having to return either one of the reinforcing bar 20 in dozens of times. Because of the many curvatures of the triangular twisted shape of the rebar 20 surface, the concrete adheres well to the rebar, so that the reinforcing bars 20 are separated from the concrete in the concrete and rotated so that the reinforcing bars connected to each other may not be separated.

7 to 9 are a perspective view, a side view and a sectional view of a rebar coupler as a first embodiment according to the present invention.

The reinforced coupler 30 according to the present invention has a tubular member 31 having a hollow equilateral triangular shape having a round cross section and protruding outwardly from the center of each side of the triangle. It is formed by twisting like a screw. At this time, the lead of the thread shape is all constant in the longitudinal direction of the rebar coupler 30, and more than three times the diameter of the rebar coupler 30 and coincides with the lead of the rebar 20. Therefore, the screw shape is made so that the inclination is 45 ° or more, it can be seen that the slope of the screw shape is very steep as shown in the figure.

Since the tubular member 31 is pipe-shaped, even if it does not have the same cross-sectional area as the reinforcing bar 20, the moment of inertia is very large and the bending rigidity is excellent. In addition, since the outer surface itself of the tubular member 31 involved in the coupling of the reinforcing bar 20 also has a triangular twisted shape in the form of a screw, the reinforcing coupler 30 also has an effect of excellent adhesion with concrete. And because the cross-section is rotated in the form of a screw along the longitudinal direction to offset the deviation of the bending stiffness along the direction.

In particular, when twisted with a lead matching the reinforcing bar 20, when connecting the two reinforcing bars 20 in the longitudinal direction can be easily connected to the site only by the rebar coupler 30.

The rib receiving portion 32 accommodates the ribs 22 of the reinforcing bar 20, and the rib receiving portion 32 itself also protrudes to the outer surface of the tubular member 31 to increase adhesion to concrete, and at the center of each side. Because it is located at, it reinforces the bending stiffness with respect to the bending direction which may be weak in terms of the moment of inertia relatively in the cross section of the triangle.

Here, when the lead is π times the diameter, the inclination of the thread is 45 °, so that the lead is at least three times the diameter of the reinforcing bar 30 so that the inclination of the thread is at least 45 °, as in the conventional female screw coupling method. When connecting the two reinforcing bars 20, there is no inconvenience to return one of the reinforcing bars 20 dozens of times. Due to the many curvatures of the surfaces of the reinforcement 20 and the reinforcement coupler 30 in the form of a triangle, the concrete adheres well to the reinforcement 20 and the reinforcement coupler 30, and thus the reinforcement 20 or the reinforcement coupler 30 There is no fear that the reinforcing bars connected to each other by separating and rotating with the concrete in the concrete will not be separated.

FIG. 10 is a perspective view of an example of coupling using the deformed rebar of FIG. 4 and the rebar coupler of FIG. 7, and FIG. 11 is a cross-sectional view of the coupling portion of FIG. 10.

The steel 21 and the rib 22 of the reinforcing bar 20 are accommodated in the tubular member 31 and the rib receiving part 32 of the reinforcing coupler 30 in the longitudinal direction such that the steel 21 is rotated once. It can be seen. This does not require a separate cumbersome connection work, and significantly reduces the number of revolutions of the heavy reinforcing bar is more than 8m compared to the previous bar, of course, the connection is convenient.

Looking at the cross-sectional view there is a small gap between the reinforcing bar 20 and the reinforcing bar coupler 30, which gives a very little fluidity to the connection portion, there is also the effect of seismic.

Hereinafter, a deformed rebar and a rebar coupler as a second embodiment according to the present invention will be described. Parts having the same features as the above embodiments will be omitted.

12 to 14 are a perspective view, a side view, and a sectional view of a reinforcing bar as a second embodiment according to the present invention.

As a second embodiment according to the present invention, the reinforcing bar 40 has a substantially rounded square shape in cross section, and the steel 41 having a shape in which the ribs 42 protrude outwardly in the vicinity of the center of each side of the triangle is longitudinally screwed. It is formed by twisting.

The square shape having a substantially rounded cross section is very easy to manufacture because it can be simply produced by roller molding or extrusion molding.

Steel having a square cross section is superior in bending (bending) stiffness because the moment of inertia is greater than that of a circular cross section having the same amount of material, that is, the same area. The square is advantageous in that the variation of the moment of inertia along the direction is smaller than that of the equilateral triangle. Other than that has the same characteristics as the reinforcing bar 20 is a rounded equilateral triangle cross section.

15 to 17 are a perspective view, a side view and a sectional view of a rebar coupler as a second embodiment according to the present invention.

Rebar coupler 50 according to the second embodiment of the present invention is a tubular member having a hollow square shape with a round cross section and a rib receiving portion 52 protruding outward near the center of each side of the triangle ( 51) is twisted like a screw in the longitudinal direction. The tubular member 51 having a hollow square cross section is advantageous in that the variation of the moment of inertia is smaller than that of the equilateral triangle. Otherwise, the cross section has the same characteristics as the rounded hollow triangular rebar coupler 30.

FIG. 18 is a perspective view of an example of coupling using the rebar of FIG. 12 and the rebar coupler of FIG. 15, and FIG. 19 is a cross-sectional view of the coupling portion of FIG. 18.

Since the lead is long, the steel 41 and the rib 42 of the reinforcing bar 40 are connected to the tubular member 51 and the rib receiving unit 52 of the reinforcing bar coupler 50 in the longitudinal direction such that the steel 41 is rotated once. It can be seen that it is acceptable and combinable.

20 is a side view showing a state in which the opening 33 is formed on one side of the rebar coupler as in the above embodiments and the injection hole 34 is formed on the other side. Two openings 33 are formed in the vicinity of the center with the center in the longitudinal direction of the coupler interposed therebetween. First, when rebar is inserted from the left side of the rebar coupler based on FIG. 20, the rebar is completely inserted into the left opening 33a, and when the rebar is inserted from the right side, the rebar is completely inserted into the right opening 33b.

If the rebar is not visible in the left opening 33a when the rebar is inserted from the left side, the rebar is inserted less. If the rebar is visible in the left right openings 33a and 33b, the rebar is inserted too much. Therefore, if both openings are used well, the ends of both reinforcing bars can be brought into contact with the exact center of the rebar coupler.

This opening not only confirms the insertion depth of the reinforcing bar, but also allows concrete to flow through the opening during pouring so that the concrete and the reinforcing bar are firmly attached.

Meanwhile, the rebar 20 connected by the rebar coupler 30 may be strongly fixed by injecting epoxy into the rebar coupler 30 through the injection hole 34 formed at the center of the other side.

21 is a perspective view and a cross-sectional view illustrating a state in which a plurality of rebar couplers are coupled to each other and rebars of different diameters are coupled to both sides thereof.

The present invention may also include a plurality of stages of reinforcing couplers 30 and 30a of different diameters so that the reinforcing coupler 30a and the reinforcing coupler 30a may be coupled to each other. This makes it possible to connect reinforcing bars 20 and 20a of different diameters.

For example, when reinforcing bars 20 and 20a of different diameters (20 <20a in diameter) are combined, a reinforcing bar coupler 30 having a diameter corresponding to the reinforcing bar 20 and a diameter corresponding to the reinforcing bars 20 ' When the reinforcing bar coupler 30 'is coupled to each other (diameter 30 <30'), as shown in Fig. 21, the small diameter reinforcing bar coupler 30 is connected to the small diameter reinforcing bar 20 on the left side, When the large diameter rebar coupler 30a is connected to the small diameter rebar coupler 30 again, and the large diameter rebar coupler 30a is connected to the large diameter rebar coupler 30a, the small diameter rebar 20 is eventually connected. And large diameter reinforcing bars 20a are simply connected.

In addition, as shown in FIG. 22, even when the reinforcing bar 20 having the same diameter is used to support the rebar coupler 30 and 30a by overlapping the reinforcing bar couplers 30 and 30a when the load to be supported is large and the reinforcing bar 20 is used. The strength of can also be reinforced.

As described above, the rebar and rebar coupler of the present invention is simple to manufacture, greatly improves the adhesion and rigidity while reducing the amount of material without variation in the direction, reinforcement without additional work in the construction site or production site This makes the joint work very convenient, which has a remarkable effect of saving time and money.

The present invention is not limited to the described embodiments, and various modifications and changes can be made to those skilled in the art without departing from the spirit and scope of the present invention. Such modifications or modifications may be made to the present invention. It belongs to the claims of the.

For example, reinforcing bars and reinforcing couplers having a cross-sectional shape as shown in FIG. 23 may be referred to as rounded equilateral triangles or squares, which can be easily manufactured by roller or extrusion.

Claims (28)

 Steel having a round or triangular cross section is twisted in the form of a screw having a slant of approximately 45 ° with a predetermined lead along a longitudinal direction, Ribs are formed to protrude along the longitudinal direction of the steel in the central portion of each side of the triangular or rectangular shape of the steel, The lead is characterized in that the reinforcement coincides with the lead of the rebar coupler to be fastened with the rebar.  A hollow tubular member having a triangular shape or a square shape having a round cross section is twisted in a screw shape with a predetermined lead along a longitudinal direction, In the central portion of each side of the triangular or rectangular shape of the tubular member, the rib receiving portion is formed to protrude outward along the longitudinal direction of the tubular member, The lead corresponds to the lead of the rebar to be fastened to the rebar coupler, Reinforcing bar coupler, characterized in that the shape of the inner diameter and the shape of the outer diameter coincide with the other reinforcing bar coupler to the outside of one rebar coupler having a different diameter. The method according to claim 2, Rebar coupler, characterized in that the inclination of the screw thread is approximately 45 °. The method according to claim 2 or 3, Reinforcing bar coupler, characterized in that the opening is formed near the center in the longitudinal direction of the side of the reinforcing bar coupler. The method according to claim 4, Reinforcing bar coupler, characterized in that the opening is formed with two between the center, so that the insertion depth of each reinforcing bar inserted through each opening can be confirmed. The method according to claim 2 or 3, Reinforcing bar coupler, characterized in that the injection hole is formed in the vicinity of the center of the longitudinal direction of the reinforcing bar coupler injection.  Steel having a rounded triangular or rectangular cross section is twisted into a predetermined lead along a longitudinal direction in the form of a screw having an inclination of approximately 45 ° of thread, as well as a central portion of each side of the triangular or rectangular shape of the steel. The reinforcing bars protruding ribs along the longitudinal direction, and hollow tubular members having a rounded triangular shape or a rectangular cross section are twisted in the form of screws with predetermined leads identical to the reinforcing bars along the longitudinal direction, as well as the tubular members. In the center of each side of the triangular shape or the square shape of the reinforcing bar coupler formed to protrude outwardly along the longitudinal direction of the tubular member, Connecting the reinforcing bars by screwing each end of the two reinforcing bars to be connected to both ends of the reinforcing bar coupler. The method according to claim 7, A method of connecting reinforcing bars, characterized in that when connecting the ends of two reinforcing bars, a plurality of reinforcing bar couplers having the same lead and different diameters overlap. The method according to claim 8, Regarding the overlapping reinforcing bar coupler, one side of the rebar coupler having a smaller diameter connects the reinforcing bar with a smaller diameter, and the other side of the rebar coupler having the larger diameter connects the reinforcing bar with the larger diameter. . The method according to any one of claims 7 to 9, The method of connecting the reinforcing bar, characterized in that for checking the insertion depth of the reinforcing bar through the opening that can confirm the insertion depth of the reinforcing bar formed near the center in the longitudinal direction of the rebar coupler side. The method according to claim 10, The opening is formed in two with a center between the center, so as to confirm the insertion depth of each reinforcing bar inserted through each opening, the method for connecting the reinforcing bars. The method according to any one of claims 7 to 9, The method of connecting the reinforcing bars, characterized in that for fixing the reinforcing bars by injecting a fixing agent through the injection hole for injecting the fixing agent near the center in the longitudinal direction of the rebar coupler side.  Steel having a round or triangular cross section is twisted in the form of a screw having an inclination of approximately 45 ° of thread with a predetermined lead along the longitudinal direction, as well as the length of the steel at the center of each side of the triangular or rectangular shape of the steel. Two reinforcing bars protruding ribs along the direction, and hollow tubular members having a rounded triangular shape or a square cross section are twisted in the form of screws with predetermined leads identical to the two reinforcing bars in the longitudinal direction, as well as the tubular shape. A reinforcing bar coupler in which the rib receiving portion protrudes outwardly along the longitudinal direction of the tubular member at a central portion of each side of the triangular or rectangular shape of the member, Reinforcing bar connecting structure, characterized in that each end of the two reinforcing bars to be connected to each other by screwing the two ends of the reinforcing bar coupler. The method according to claim 13, Reinforcing bar connection structure, characterized in that when connecting the ends of the two reinforcing bars, a plurality of reinforcing bar couplers having the same diameter and different diameters. The method according to claim 14, Reinforcing bar connection structure, characterized in that the reinforcing bar coupler, the smaller diameter reinforcing bar is connected to one side of the smaller diameter coupler, the larger diameter reinforcing bar is connected to the other side of the larger diameter coupler. The method according to any one of claims 13 to 15, Reinforcing bar connecting structure, characterized in that the opening is formed near the center in the longitudinal direction of the rebar coupler side to determine the insertion depth of the rebar. The method according to claim 16, Reinforcing bar connecting structure, characterized in that the two openings are formed so as to determine the insertion depth of each reinforcing bar inserted through each opening. The method according to any one of claims 13 to 15, Reinforcing bar connection structure, characterized in that the injection hole is formed in the vicinity of the center of the longitudinal direction of the reinforcing bar coupler to inject a fixing agent for fixing the reinforcing bar. delete delete delete delete delete delete delete delete delete delete

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