JP2000265618A - Molding method for anchoring part of reinforcement, reinforcement, and reinforcement construction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molding method for an anchoring part of reinforcements capable of reliably controlling strength and capable of inexpensively arranging the anchoring part in the reinforcements, the reinforcements molded by using this molding method and a reinforcement construction method using these reinforcements. SOLUTION: An anchoring part is molded for anchoring reinforcements 20 to concrete placed by using an anchoring part molding device 1 having a heating means for heating end parts of the two reinforcements 20, 20 and a pressurizing means (for example, a gas burner) for mutually pressurizing these reinforcements 20, 20 by the mutual end parts by respectively holding the reinforcements 20, 20. The end parts of the reinforcements 20, 20 are heated by the heating means, these end parts are thermally deformed while mutually pressurizing these two reinforcements 20, 20 by the mutual end parts, and the anchoring part is simultaneously molded in the end parts of these two reinforcements 20, 20. Thus, the reinforcements 20 of molded the anchoring part 25 are used to construct a concrete structure part of a building.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a fixing portion of a reinforcing bar, a reinforcing bar formed by using the forming method, and a reinforcing bar using the reinforcing bar.

[0002]

2. Description of the Related Art A conventional technique will be described below with reference to FIGS. FIG. 9 is a schematic view showing a conventional bent portion of a reinforcing bar, FIG. 10 is a front view showing an end portion of a reinforcing bar having a conventional welding type end plate, and FIG. 11 is a conventional screw type grout injection type end plate. It is a front view which shows the end part of the rebar which has.

[0003] In order to fix a reinforcing bar to concrete to be poured, a method of bending an end of the reinforcing bar to provide a fixed length is generally used. However, as shown in FIG. 9, for example, in the arrangement of the bars in the beam-to-column joint, the column main bar 100 and the bent fixing portion 101a of the beam main bar 101 overlap, and the reinforcing bar becomes extremely crowded at this portion (actually, the beam in the diagram is (Because there is also an anchoring part of the beam main reinforcing bar that is orthogonal at the beam-column joint), it often caused construction and structural problems.

[0004] In order to cope with such a problem that the reinforcing bars are crowded, an end plate (fixing portion) for fixing the reinforcing steel to the concrete to be struck is provided without bending the main reinforcing bar in the beam-column joint and fixing the reinforcing steel to the concrete to be welded. There is a technique of using a reinforcing bar provided at an end as a beam main reinforcing bar.

[0005] As one of typical rebars provided with fixing portions at the ends, as shown in FIG.
There is a welding type in which an end portion of the fixing portion 111 is welded to the fixing portion 111 and the fixing force of the reinforcing bar 110 is obtained by the fixing portion 111.

A grout type reinforcing bar having a fixing portion at an end thereof is another typical one.
In this grout type rebar, as shown in FIG.
A fixing member 123 in which the fixing unit 122 and the mounting unit 121 are integrated is used. The mounting part 121 is a nut-shaped one with an external thread cut inside. In addition, a reinforcing bar 120 formed in a male screw is used as the reinforcing bar. Then, the end of the reinforcing bar 120 is screwed into the mounting portion 121, and grout is injected and solidified into the mounting portion 121 to thereby form the reinforcing bar 120.
Are fixed to the fixing member 123.

Conventionally, such a fixing section 111 or fixing section 123, which is more compact than the bending fixing section, is provided at the end of the reinforcing bar, and the reinforcing bar is fixed to the concrete to be cast by the fixing section 111 or the fixing section 123. This prevented the reinforcing bars from becoming crowded.

[0008]

However, of the above-mentioned conventional techniques, in the case of the welding type, when the reinforcing bar 110 is welded to the fixing portion 111, the end portion of the reinforcing bar 110 is required to secure the strength of the welded portion. It was necessary to cut down and make a groove. Therefore, there is a problem that the work is troublesome and there is a problem that as the diameter of the reinforcing bar increases, it becomes difficult to perform welding management for securing the strength of welding.

Further, in the case of the grout type, there is a problem that a general deformed reinforcing bar cannot be used because its size and shape are specified (for example, it is necessary to use a screw type reinforcing bar of a specific manufacturer). . In addition, this type may be problematic in terms of cost.

Accordingly, an object of the present invention is to provide a method of forming a fixing portion of a reinforcing bar, which makes it possible to provide a fixing portion on a reinforcing bar reliably and inexpensively, a reinforcing bar formed by using this forming method, And a reinforcing bar construction method using the reinforcing bar.

[0011]

According to a first aspect of the present invention, there is provided a method for forming a fixing portion of a reinforcing bar, wherein the reinforcing portion is heated and deformed by heating. A fixing portion for fixing the reinforcing steel to concrete.

According to the first aspect of the present invention, since the fixing portion is molded by heating and thermally deforming the end of the reinforcing bar, since the fixing portion and the main body of the reinforcing bar are originally integrated, the fixing portion is formed. Even after molding, the integrity of the main body of the rebar and the fixing portion can be increased. Accordingly, it is easy to control the strength of the fixing unit. Further, since the fixing portion can be provided only by heating and thermally deforming the end portion of the reinforcing bar, the fixing portion can be provided at a lower cost than, for example, a grout type.

The fixing portion may be formed on one reinforcing bar at a time, or may be formed on two reinforcing bars at the same time as in the invention according to any one of claims 4 to 9. It is good. Further, the dimension of the fixing portion is, for example, formed to be 2.5 times or more the diameter of the reinforcing bar. The shape of the fixing portion is, for example, a disk shape (a disk shape or a rectangular parallelepiped plate shape).

According to a second aspect of the present invention, there is provided a method of forming a fixing portion of a reinforcing bar according to the first aspect, wherein the fixing portion is bulged at an end portion of the reinforcing bar in a radial direction larger than a shaft diameter of the reinforcing bar. It is characterized by being a department.

According to the second aspect of the present invention, the fixing unit includes:
Since the swelling portion is a swelling portion swelling in the radial direction at the end of the rebar at the end of the rebar, the swelling portion preferably captures the concrete to be cast, and the rebar is suitable for the concrete to be cast Can be fixed.

According to a third aspect of the present invention, there is provided the method for forming a fixing portion of a reinforcing bar according to the first or second aspect, wherein a forming form for adjusting the shape of the fixing portion is provided around an end of the reinforcing bar. The method is characterized in that the molding is performed in a state where the components are arranged.

According to the third aspect of the present invention, the end portion of the reinforcing bar is heated and thermally deformed in a state where the molding form for adjusting the shape of the fixing portion is disposed around the end portion of the reinforcing bar. Since the portion is molded, the fixing portion can be molded into a desired shape corresponding to the shape of the molding frame.

Here, when the fixing portion is formed on two rebars at the same time as in the invention according to any one of claims 5 to 10, the shape of the forming frame is, for example, cylindrical. While heating the end of the reinforcing bar,
The fixing of the fixing portion is performed by mutually pressing the ends of the reinforcing bars of the book. When the fixing section is formed on one reinforcing bar at a time, the shape of the forming frame is, for example, a cylindrical shape having a bottom surface, and the end of the reinforcing bar is heated while being heated. The fixing section is formed by pressing the end of the reinforcing bar.

According to a fourth aspect of the present invention, there is provided the method of molding a fixing portion of a reinforcing bar according to the third aspect, wherein the molding form is removed from the fixing portion smoothly after the molding. The above-mentioned molding is performed in a state in which a release material is applied to the substrate.

According to the fourth aspect of the present invention, the end of the reinforcing bar is heated in a state in which a mold release material is applied to a molding form provided around the end of the reinforcing bar to adjust the shape of the fixing portion. Since the fixing unit is molded by the fixing unit, the molding frame can be smoothly removed from the fixing unit after the molding of the fixing unit.

The release material is, for example, a powder of a substance having a higher melting point than iron. In addition, examples of the substance having a higher melting point than iron include cement and refractory brick. Further, in order to apply such a release material, an adhesive may be applied to a mold in advance, and then the release material may be applied thereon.

The invention according to claim 5 is the invention according to claims 1, 2, and 3.
Or a method of molding a fixing portion of a reinforcing bar according to 4, wherein the heating is performed on the ends of two reinforcing bars,
The present invention is characterized in that the rebars are thermally deformed while mutually pressing the rebars at the ends, and the fixing portion is simultaneously molded at the ends of the two rebars.

According to the fifth aspect of the present invention, the ends of the two rebars are heated, and the two rebars are thermally deformed while the ends are pressed against each other.
Since the fixing portion is formed at the end of the reinforcing bar at the same time, the forming operation of the fixing portion can be made more efficient.

According to a sixth aspect of the present invention, there is provided the method for forming a fixing portion of a reinforcing bar according to the fourth aspect, wherein welding is performed between the ends of the two reinforcing bars to prevent welding of the ends of the reinforcing bars. The method is characterized in that the molding is performed with a prevention means interposed.

According to the sixth aspect of the present invention, the fixing portion is formed between the ends of the two reinforcing bars by interposing a welding preventing means for preventing welding of the ends of the reinforcing bars. It is possible to prevent the ends of the reinforcing bars from being welded to each other during the operation. Therefore, the ends of the two rebars can be reliably separated from each other after the fixing portion is molded.

As the means for preventing the welding, as in the invention according to claim 7, a welding prevention material for preventing the welding of the ends of the reinforcing bars is applied to both surfaces of the film. It may be a material in which a welding prevention material for preventing welding between portions is applied to both sides of the plate, or a welding prevention material applied to an end of a reinforcing bar. The material of the plate is metal,
Ceramics and the like can be mentioned. As a welding prevention material for preventing welding between the ends of the reinforcing bars, there is a powder of a substance having a higher melting point than iron. In order to apply these powders to an end of a plate, a film, or a reinforcing bar, for example, an adhesive is applied and then these powders are applied. In addition, examples of the substance having a higher melting point than iron used here include cement and refractory brick.

According to a seventh aspect of the present invention, there is provided a method for forming a fixing portion of a reinforcing bar according to the sixth aspect, wherein the welding preventing means comprises:
The present invention is characterized in that a welding prevention material for preventing welding between the ends of the two rebars is a welding prevention film applied to both surfaces of the film.

When a plate is used as the welding prevention means,
Depending on the thickness and material of the plate, or the magnitude of the pressure applied between the ends of the reinforcing bars, the plate may be broken. In this case, the generated pieces of the plate may adversely affect the shape of the fixing unit to be molded.

Therefore, according to the invention of claim 7, 2
A welding prevention means, which is a welding prevention film in which a welding prevention material for preventing the welding between the ends of the reinforcing bars is applied to both sides of the film, is interposed between the ends of the two reinforcing bars to form the fixing portion. So, for example, as in the case of using a plate as the welding prevention means, by the fragments generated by the cracking of the welding prevention means,
It is possible to prevent the shape of the molded fixing portion from being adversely affected, thereby preventing the strength of the fixing portion from being adversely affected. Therefore, the fixing unit can be formed into a desired shape.

Examples of the film include aluminum foil. Even if a film such as aluminum foil melts and adheres to the fixing part, the molten film can be removed by rubbing it off with a brush etc. after molding the fixing part. Therefore, even after the removal, almost no adverse effect is left on the shape of the fixing portion.

According to an eighth aspect of the present invention, there is provided a method of forming a fixing portion of a reinforcing bar according to the sixth or seventh aspect, wherein the diameter of the welding prevention means is at least three times the diameter of the reinforcing bar. I have.

According to the eighth aspect of the present invention, since the diameter of the welding prevention means is three times or more the diameter of the reinforcing bar, even if the size of the fixing portion is formed to be about 2.5 times the diameter of the reinforcing bar, After the fixing portion is formed, the fixing portions formed at the ends of the two rebars can be reliably separated from each other.

According to the ninth aspect of the present invention, there are provided the fifth, sixth and seventh aspects.
Or the method of molding a fixing portion of a reinforcing bar according to claim 8, wherein
A fixing unit molding device comprising: a heating unit for performing the heating of the ends of the reinforcing bars; and a pressing unit that holds the two reinforcing bars and presses the reinforcing bars mutually at the ends. It is characterized in that the fixing section is molded by using the same.

According to the ninth aspect of the present invention, the ends of the two rebars are heated by the heating means of the fixing unit molding apparatus.
The fixing unit can be surely formed by holding the two rebars by the pressurizing means of the fixing unit forming device and pressing the rebars mutually at the ends.

According to a tenth aspect of the present invention, there is provided a method for forming a fixing portion of a reinforcing bar according to the eighth aspect, wherein the fixing portion forming device is a general-purpose gas pressure welding device.

According to the tenth aspect of the present invention, since a gas pressure welding device generally used in civil engineering construction sites or the like is transferred to a steel bar for pressure welding and used as a fixing portion molding device, a fixing portion molding device is used. The molding can be easily performed at a civil engineering construction site or the like.

An eleventh aspect of the present invention is a reinforcing bar,
It is characterized by having the fixing part formed by using the method for forming a fixing part of a reinforcing bar according to any one of claims 1 to 10.

According to the eleventh aspect of the present invention, the first aspect
Since it is a reinforcing bar having a fixing portion formed by using the method for forming a fixing portion of a reinforcing bar according to any one of claims 10 to 14, the fixing portion and the main body of the reinforcing bar are originally integrally formed. Even after molding, it exhibits excellent integrity between the main body of the rebar and the fixing portion. In addition, since it is manufactured only by heating and thermally deforming the end of the rebar, it can be applied to any deformed rebar as compared with, for example, a grout type (see conventional technology), and can be obtained at low cost. It has such advantages.

According to a twelfth aspect of the present invention, there is provided a reinforcing bar construction method, wherein a concrete structure of a building is constructed using the reinforcing bar according to the eleventh aspect.

According to the twelfth aspect of the present invention, the first aspect is provided.
Since the concrete structure of the building is constructed by using the reinforcing bar described in 1, the end plate (fixing portion) can be prevented from being jammed in the same manner as the conventional reinforcing bar provided at the end. Further, strength management is easier than conventional welding rebars having end plates. Furthermore, it can be applied to any deformed rebar compared to the case of using grout type rebars with conventional rebars having end plates,
In addition, it has the advantage that it can be obtained at low cost.

As the reinforcing bar construction method, in addition to the case where the reinforcing bar according to claim 11 is used alone, a precast member (for example, a precast beam member) in which the reinforcing bar is embedded in advance is used for constructing a concrete structure of a building. There are things.

[0042]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below with reference to FIGS. 1 and 3
FIG. 5 to FIG. 5 are process diagrams (partially cut-away side sectional views) for explaining a method of forming a fixing portion of a reinforcing bar according to the present invention. FIG. ,
FIG. 3 is a view showing a state in which the welding prevention means is set, FIG. 4 is a view showing a state in which the ends of the reinforcing bars are pressed against each other, and FIG. FIG. 2 is a sectional view taken along the line II of FIG. 1 for explaining an attachment member for attaching the mold to the main body of the fixing unit molding apparatus, and FIG. 6 is a view for explaining a state where the mold is set. FIG. 7 is a front view showing a reinforcing bar according to the present invention, and FIG. 8 is a cross-sectional view for explaining a reinforcing bar construction method according to the present invention.

The fixing section molding apparatus 1 shown in FIG. 1 and the like is, for example, a gas pressure welding apparatus generally used in civil engineering construction sites and the like. Such a fixing unit molding device 1 is configured as follows. That is, the main body 2 has a cylindrical moving area 2.
a inside. In this moving area 2a, a columnar moving section 3 is provided so as to be able to reciprocate right and left in the moving area 2a.
Is provided. A support 4 for supporting the reinforcing bar 20 is provided above the moving unit 3. Further, a support portion 5 for supporting the reinforcing bar 20 is provided on an upper portion of the main body 2. On one side of the main body 2, a cylinder portion 8 having a moving area 8a of a ram 10 moved by hydraulic pressure is provided. By supplying oil from the oil feed pipe 6 to the hydraulic chamber 8b of the cylinder section 8 via the introduction pipe 7, the ram 10 is moved rightward in the drawing. Since the ram 10 is connected to the moving part 3 inside the moving area 2a via the connecting rod 11, the moving part 3 and the support part 4 also move rightward as the ram 10 moves rightward. The main body 2, the moving section 3, the supporting sections 4, 5, the ram 10, the cylinder section 8, the oil supply pipe 6, the introduction pipe 7, and the connecting rod 11 constitute a pressurizing means. Further, the fixing unit molding device 1
Is provided with gas burners (heating means) 50, 50 for heating the ends of the rebars 20, 20. The gas burners 50, 50 have a substantially C-shape, have a C-shape opening located on the lower side, and emit a flame toward the inner periphery of the C-shape. The gas burners 50 are configured to be able to move up and down.

A method for forming a fixing portion of a reinforcing bar using such a fixing portion forming apparatus 1 will be described below. First, as shown in FIG. 1, in a state where the ends of the reinforcing bars 20, 20 are opposed to each other, the reinforcing bars 20, 20 are respectively attached to the support portions 4, 5.
Are attached, and the reinforcing bars 20, 20 are
To support. Then, in this state, the gas burner 50,
The heating is performed until the ends of the reinforcing bars 20 and 20 turn red by 50. Here, a fixing unit for attaching a fixing unit molding ring (molding frame) 45 for adjusting the shape of the fixing units 25, 25 formed at the ends of the reinforcing bars 20, 20 to the fixing unit molding device 1. At this point, the lower part 40 of the molding ring 45 is previously attached to the lower part of the main body 2 of the fixing part molding apparatus 1 (see FIG. 2).

Before the ends of the heated rebars 20, 20 are brought into contact with each other, the gas burners 50, 50 are once raised and separated from the ends of the rebars 20, 20, as shown in FIG. Then, between the ends of the reinforcing bars 20, 20, a welding prevention means 30 for preventing welding of the ends of the reinforcing bars 20, 20 is set. This welding prevention means 30
For example, cement powder (a powder of a substance having a higher melting point than iron) is adhered to both surfaces of an aluminum foil (film) by an adhesive. The diameter of the welding prevention member 30 is
For example, it is assumed that the diameter is set to about three times the diameter of the reinforcing bars 20.

After the welding prevention means 30 is set, the gas burners 50 are lowered again. Then, the ram 10, the connecting rod 11, the moving part 3, the support part 4, and the rebar 20 are moved to the right by hydraulic pressure while the ends of the rebars 20, 20 are heated by the gas burners 50, 50,
As shown in FIG. 4, the end of the reinforcing bar 20 is pressed against the end of the reinforcing bar 20. In other words, the rebars 20, 20 are mutually pressed at the ends. Then, the ends of the rebars 20, 20 that are easily deformed due to the high temperature are thermally deformed and swell to the outer peripheral side, so that the bumps 20a, 20a are gradually formed as shown in FIG.

When the diameter of the bumps 20a becomes about twice the diameter of the rebars 20, 20, the lower part 40 of the fixing part molding ring 45 previously attached to the fixing part molding device 1 (FIG. 2). Etc.), FIG. 5 and FIG.
As shown in (2), the middle part 41 of the fixing part molding ring 45 is screwed, and the upper part 42 of the fixing part molding ring 45 is further screwed thereon. In this state, the inner periphery 41a of the upper semi-cylindrical portion of the middle portion 41 and the inner periphery 42a of the upper portion 42
A cylindrical molded part 43 is formed. This molded part 43
Is set to, for example, 2.5 times the diameter of the rebars 20, 20.

The molding section 43 includes a fixing section 2 described later.
After the molding of the fixing parts 5 and 25, a releasing material is applied in advance so that the middle part 41 and the upper part 42 of the fixing part forming ring 45 can be smoothly removed from the fixing parts 25 and 25. This release material is, for example, a powder of cement. For example, an adhesive is applied to the molded portion 43 and then sprayed thereon.

Then, by continuing to pressurize the heated ends of the rebars 20, 20, the bulges 20a, 20a further expand, and eventually the bulges 20a, 20a,
20a contacts the inside of the molded portion 43. Further, by continuously pressing the ends of the reinforcing bars 20, 20, the contact surfaces between the bulges 20a, 20a and the molded portion 43 reach the entire inner surface of the molded portion 43, as shown in FIG. Then, heating and pressurization are stopped. In this state, the bulges 20a, 20a
“a” is formed in a disk shape corresponding to the shape of the inner circumference of the molded portion 43. The bulges 20a, 20a
Is about 2.5 times the diameter of the reinforcing bar 20.

When the heating and pressurization are stopped, the molding section 43
Is removed from the bulges 20a, 20a (fixing sections 25, 25). At this time, the bulge 20
a and the bulge 20a and the molded portion 43 can be easily removed from the mold. Note that the molding form 45 is thermally deformed and the fixing sections 25, 25
Heating of the ends of the rebars 20, 20
It is desirable that the adjustment be performed near the axis of the reinforcing bars 20.

The bulge 20 is formed by the action of the welding prevention means 30 interposed between the two rebars 20.
The bulge 20a and the bulge 20a are not welded, and the bulge 20a and the bulge 20a are easily separated by returning the ram 10 to its original position. These bulges 20a are rebar fixing heads (fixing portions) 25, 25. Here, even when the aluminum foil is melted and adhered to the fixing portions 25, 25, the molten aluminum can be removed by rubbing off with a brush or the like. Almost no adverse effect on the shape. Thus, the fixing unit 2 for fixing the reinforcing bar 20 to the concrete to be poured is provided.
5 are produced according to the present invention.

In the reinforcing bar 20 provided with the fixing unit 25 in this manner, since the fixing unit 25 and the main body of the reinforcing bar 20 are originally integrated, the main body of the reinforcing bar 20 and the fixing unit 25 are formed even after the fixing unit 25 is molded. With excellent integrity. Further, since it is manufactured only by heating and thermally deforming the end portion of the rebar 20, it can be applied to any deformed rebar as compared with, for example, a grout type (see conventional technology) and the like, and can be obtained at low cost. It has the advantage that it can be done.

Further, in the reinforcing bar construction method of constructing a concrete structure portion of a building using such a reinforcing bar 20, compared with the case of using a conventional bending fixing portion (see FIG. 9),
Since the fixing portion 25 of the reinforcing bar 20 can be set compactly,
As in the case of using a conventional reinforcing bar provided with an end plate (fixing portion) at the end, as shown in FIG.
0, 20 can be prevented from becoming crowded. At the same time, the integration between the fixing unit 25 and the main body of the reinforcing bar 20 is excellent, and
Since the rebar 20 can be obtained at low cost, the rebar construction method can be implemented at low cost. Variations of this rebar construction method include, in addition to using the rebar 20 alone,
A precast member (for example, a precast beam member) in which the reinforcing bar 20 is embedded in advance may be used for constructing a concrete structure of a building.

As described above, according to the above-described embodiment of the present invention, the fixing portion 25 is molded by heating and thermally deforming the end portion of the reinforcing bar 20. The integration with the main body can be enhanced. Accordingly, it is easy to control the strength of the fixing unit. further,
Fixing section 2 simply by heating and thermally deforming the end of rebar 20
5 can be applied to any deformed rebar as compared with, for example, grout type ones, and the fixing part can be provided at low cost.

Further, since the fixing portion 25 is a bulging portion that bulges at the end of the reinforcing bar 20 in the radial direction (for example, about 2.5 times the diameter of the reinforcing bar 20) than the shaft diameter of the reinforcing bar, It is possible to suitably capture the concrete on which the portion, that is, the fixing portion 25 is cast, and to suitably fix the reinforcing bar 20 to the concrete to be cast.

Further, since the fixing section 25 is molded in a state where the molding form 45 for adjusting the shape of the fixing section 25 is disposed around the end of the reinforcing bar 20, the fixing section 25 is formed in accordance with the shape of the molding form 45. The fixing unit 25 can be formed into a desired shape.
At this time, since the fixing section 25 is molded in a state where the release material is applied to the molding form 45, the molding form 4 is formed after the fixing section 25 is molded.
5 can be removed from the fixing section 25 smoothly.

Further, the ends of the two rebars 20, 20 are heated, and the two rebars are thermally deformed while the ends are pressed against each other. Since the fixing section 25 is molded at the same time, the molding operation of the fixing section 25 can be made more efficient.

The fixing portion 25 is formed between the ends of the two reinforcing bars 20 by interposing a welding prevention means 30 for preventing the ends of the reinforcing bars 20, 20 from being welded to each other. It is possible to prevent the ends of the reinforcing bars 20, 20 from being welded to each other. Therefore, the ends of the two rebars 20, 20 can be reliably separated from each other after the molding of the fixing portion.

Here, when a plate is used as the welding prevention means 30, the thickness and material of the plate, or the reinforcing bars 20, 20
Depending on the magnitude of the pressure applied between the ends of the plates, the plate may be broken. In this case, due to the resulting fragments of the board,
There is a possibility that the shape of the molded fixing section 25 will be adversely affected. Therefore, the welding prevention means 30 which is a welding prevention film in which a welding prevention material for preventing the welding of the ends of the two reinforcing bars 20, 20 is applied to both surfaces of the film (aluminum foil) is used. Since the fixing portion 25 is formed by being interposed between the ends of the fixing portion 25, the shape of the formed fixing portion 25 is adversely affected as in the case where a plate is used as the welding prevention means 30, for example. Can be prevented. Accordingly, the fixing unit 25 can be formed into a desired shape.

In addition, since the diameter of the welding prevention means 30 is three times or more the diameter of the reinforcing bar, the dimension of the fixing portion 25 is
Even if the fixing portion 25 is molded to about 2.5 times the diameter of the fixing portion 25, the fixing portions 25, 25 formed at the ends of the two rebars 20, 20 can be reliably separated from each other after the fixing portion 25 is formed.

The ends of the two rebars 20, 20 are heated by the heating means (gas burner) of the fixing part molding apparatus 1, and the pressing means (main body 2, moving part 3, The support parts 4 and 5, the oil supply pipe 6, the introduction pipe 7, the cylinder part 8, the ram 10, and the like).
Since the rebars 20, 20 are pressed against each other at their ends while holding the respective 0, 20, the fixing portion 25 can be reliably molded. At this time, by using a gas pressure welding device generally used in civil engineering construction sites and the like as the fixing unit molding device 1, molding of the fixing unit 25 can be easily performed in civil engineering construction sites and the like.

Further, according to the reinforcing bar 20 manufactured by the method of forming a fixing portion of a reinforcing bar according to the present invention, since the fixing portion 25 and the main body of the reinforcing bar 20 are originally integrated, the fixing portion 25 can be formed even after forming. Excellent integration between the main body of the reinforcing bar 20 and the fixing unit 25 is exhibited. Further, since it is manufactured only by heating and thermally deforming the end portion of the rebar 20, it can be applied to any deformed rebar as compared with, for example, a grout type (see conventional technology) and the like, and is inexpensive. It has the advantage that it can be obtained.

In addition, according to the rebar construction method using the rebar according to the present invention, since the concrete structure of the building is constructed using the rebar 20, the end plate (fixing portion) is provided at the end. As in the case of the above-mentioned reinforcing bars, it is possible to prevent the reinforcing bars from becoming jammed. In addition, the excellent fixing portion has strength, and the rebar construction method can be implemented at low cost.

In the above-described embodiment, the method of molding the fixing portion 25 by pressing the two rebars 20, 20 end to end with each other is illustrated. Although the shape of ()) is cylindrical, for example, when the fixing portion is formed on one reinforcing bar, the shape of the forming frame is, for example, a cylindrical shape having a bottom surface, and the end of the reinforcing bar is heated while heating. The fixing unit may be molded by applying pressure to the molding frame. Although a gas pressure welding device is used as the fixing unit molding device 1, a heating unit for heating the end of the reinforcing bar, and a pressing unit for holding the reinforcing bar and pressing the reinforcing bar mutually at the ends are provided. Other devices may be used as long as they can perform a molding operation. Further, although the shape of the fixing unit 25 is a disk shape, other shapes may be used as long as the shape of the fixing unit 25 is a disk shape. Further, as the anti-welding means 30, cement powder as an anti-welding material was applied to both surfaces of the aluminum foil with an adhesive, but as the anti-welding means 30,
A plate or the like may be used. In addition, although cement powder is exemplified as the welding prevention material, powder of a substance having a higher melting point than iron (for example, refractory brick) may be used. In addition, in the procedure of the molding method, the timing at which the middle part 41 and the upper part 42 of the molding form 45 are attached is when the diameter of the bulges 20a, 20a is about twice the diameter of the reinforcing bar 20,
It may be attached at a timing before this.

[0065]

According to the method of forming a fixing portion of a reinforcing bar according to the first aspect of the present invention, since the fixing portion and the main body of the reinforcing bar are originally integrated, the integrity of the main body of the reinforcing bar and the fixing portion is improved. It can be high, and the strength management of the fixing unit becomes easy. Also, since it is only necessary to heat and deform the end of the reinforcing bar, it can be applied to any deformed reinforcing bar as compared with, for example, a grout type bar, and a fixing unit can be provided at low cost.

According to the method for molding a fixing portion of a reinforcing bar according to the second aspect of the present invention, the fixing portion is a bulging portion which is bulged in the end portion of the reinforcing bar in the radial direction than the shaft diameter of the reinforcing bar. The concrete on which the bulging portion is cast can be suitably captured, and the reinforcing steel can be suitably fixed to the concrete to be cast.

According to the method of molding a fixing portion of a reinforcing bar according to the third aspect of the present invention, the end of the reinforcing bar is arranged in a state in which a molding form for adjusting the shape of the fixing portion is disposed around the end of the reinforcing bar. Is heated and thermally deformed to form the fixing section, so that the fixing section can be molded into a desired shape corresponding to the shape of the molding frame.

According to the method of forming a fixing portion of a reinforcing bar according to the fourth aspect of the present invention, the fixing portion is molded in a state in which the release material is applied to the molding form. It can be easily removed from the part.

According to the method of forming a fixing portion of a reinforcing bar according to the fifth aspect of the present invention, the ends of the two reinforcing bars are thermally deformed while mutually pressing each other, and the ends of the two reinforcing bars are deformed. Since the fixing section is molded at the same time, the molding operation of the fixing section can be made more efficient.

According to the method of forming a fixing portion of a reinforcing bar according to the present invention, the welding between the ends of the reinforcing bars is prevented by the welding preventing means interposed between the ends of the two reinforcing bars. After the molding of the fixing portion, the ends of the two rebars can be reliably separated from each other.

According to the method for forming a fixing portion of a reinforcing bar according to the present invention, the welding preventing means applies the welding preventing material for preventing the welding between the ends of the two reinforcing bars on both surfaces of the film. Since it is a welding prevention film, it is possible to prevent the shape of the molded fixing portion from being adversely affected. Therefore, the fixing unit can be formed into a desired shape.

According to the method of forming a fixing portion of a reinforcing bar according to the present invention, the diameter of the welding prevention means is three times or more the diameter of the reinforcing bar. Even if it is molded about five times, it is possible to reliably separate the fixing portions from each other after forming the fixing portions of the two reinforcing bars.

According to the method of forming a fixing portion of a reinforcing bar according to the ninth aspect of the present invention, the heating means of the fixing portion forming device performs two-step fixing.
By heating the ends of the rebars, holding the two rebars by the pressurizing means of the fixing part forming device, and pressing the ends of these rebars together, the molding of the fixing part is ensured. It can be carried out.

According to the method of forming a fixing portion of a reinforcing bar according to the tenth aspect of the present invention, the fixing portion forming device which is a gas pressure welding device generally used in civil engineering construction sites and the like is used.
The fixing section can be easily formed at a civil engineering construction site or the like.

According to the reinforcing bar according to the eleventh aspect of the present invention, since it is a reinforcing bar having a fixing portion formed by using the method for forming a fixing portion of a reinforcing bar according to any one of the first to ninth aspects, , Exhibiting excellent integration between the main body of the reinforcing bar and the fixing portion. Further, since it is manufactured by simply heating and thermally deforming the end of the reinforcing bar, it has an advantage that it can be applied to any deformed reinforcing bar as compared with, for example, a grout type bar and can be obtained at low cost.

According to the reinforcing bar construction method according to the twelfth aspect of the present invention, since it is not necessary to use the bent fixing portion, it is possible to prevent the reinforcing bars from being jammed. Further, strength management is easier than conventional welding rebars having end plates. Furthermore, it can be applied to any deformed rebar as compared with the grout type rebar of the conventional rebar, and can be obtained at low cost.

[Brief description of the drawings]

FIG. 1 is a process diagram (partially broken side sectional view) for illustrating a method of molding a fixing portion of a reinforcing bar according to the present invention;
FIG. 5 is a diagram illustrating a state in which a reinforcing bar is set in the fixing unit molding device.

FIG. 2 is a sectional view taken along the line II of FIG. 1 for explaining an attachment member for attaching a mold to a main body of the fixing unit molding apparatus.

FIG. 3 is one of process diagrams (partially broken side sectional view) for explaining a method of molding a fixing portion of a reinforcing bar according to the present invention;
It is a figure showing the state where welding prevention means was set.

FIG. 4 is one of process drawings (partially broken side sectional view) for explaining a method for molding a fixing portion of a reinforcing bar according to the present invention;
It is a figure which shows the press-contact state of the end parts of a rebar.

FIG. 5 is one of process diagrams (partially broken side sectional view) for explaining a method for molding a fixing portion of a reinforcing bar according to the present invention;
FIG. 3 is a diagram illustrating a molding state of a fixing unit by a mold.

FIG. 6 is a view for explaining a state where a mold is set;
It is II-II sectional drawing.

FIG. 7 is a front view showing a reinforcing bar according to the present invention.

FIG. 8 is a cross-sectional view for explaining a rebar construction method according to the present invention.

FIG. 9 is a schematic diagram showing a conventional bending and fixing part of a reinforcing bar.

FIG. 10 is a front view showing an end of a reinforcing bar having a conventional welding type end plate.

FIG. 11 is a front view showing an end portion of a reinforcing bar having a conventional screw type grouting type end plate.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 gas pressure welding device (fixing unit molding device) 2 body of gas pressure welding device (comprising pressurizing means) 3 moving unit (comprising pressurizing means) 4 support unit (comprising pressurizing means) 5 support unit (pressurizing means) 6 Oil feed pipe (constituting pressurizing means) 7 Introductory pipe (constituting pressurizing means) 8 Cylinder section (constituting pressurizing means) 10 Ram (constituting pressurizing means) 11 Connecting rod (constituting pressurizing means) Configuration) 20 Reinforcing bar 20a Swelling 25 Fixing part 30 Welding prevention means 43 Molding part of fixing part forming ring 45 Fixing part forming ring (molding form) 50 Gas burner (heating means)

Claims (12)

[Claims] 1. A method of forming a fixing portion of a reinforcing bar, wherein an end portion of the reinforcing bar is heated and thermally deformed to form a fixing portion for fixing the reinforcing bar to concrete to be poured. 2. The method according to claim 1, wherein the fixing portion is a bulging portion bulging at an end portion of the reinforcing bar in a radial direction from a shaft diameter of the reinforcing bar. 3. The fixing of a reinforcing bar according to claim 1, wherein the forming is performed in a state where a forming form for adjusting the shape of the fixing unit is arranged around an end of the reinforcing bar. How to mold the part. 4. The molding according to claim 3, wherein after the molding, the molding is performed in a state where a molding material is applied to the molding mold so that the molding mold can be smoothly removed from the fixing portion. A method for molding the anchoring portion of a reinforcing bar. 5. The heating of the ends of the two rebars, and the two rebars are thermally deformed while the ends are pressed against each other. 5. The method according to claim 1, wherein the fixing portion is formed simultaneously with the end portion. 6. The reinforcing bar according to claim 5, wherein said forming is performed by interposing welding prevention means for preventing welding between the ends of said reinforcing bars between the ends of said two reinforcing bars. How to mold the fixing section. 7. The welding prevention means according to claim 6, wherein said welding prevention means is a welding prevention film in which a welding prevention material for preventing welding between ends of said two rebars is applied to both surfaces of said film. The method of molding the anchoring part of the rebar. 8. The diameter of the welding prevention means is 3 times the diameter of the reinforcing bar.
The method for molding a fixing portion of a reinforcing bar according to claim 6 or 7, wherein the number is twice or more. 9. A heating means for heating the ends of the two rebars, and a pressurizing means for holding the two rebars and pressing the rebars together at the ends. 9. The method of molding a reinforcing bar fixing section according to claim 5, wherein the fixing section is molded using a fixing section molding apparatus provided. 10. The method according to claim 9, wherein said fixing unit molding device is a general-purpose gas pressure welding device. 11. A reinforcing bar having the fixing portion formed by using the method for forming a fixing portion of a reinforcing bar according to any one of claims 1 to 10. 12. A reinforcing bar construction method comprising constructing a concrete structure of a building using the reinforcing bar according to claim 11.