JP2023058229A - Method and tool for bending reinforcement - Google Patents

Abstract

To provide a simple method for bending a reinforcement, which can reduce time and labor for bending the reinforcement extending from a construction joint surface.SOLUTION: The method for bending a reinforcement 100 extending from the construction joint surface 110 of concrete installed beforehand uses a first tool 10 having a grip 12 that grips the reinforcement 100 and a pressing jack 50, sets the grip 12 at a prescribed position of the reinforcement 100 to temporarily fix the first tool 10, and presses the end of the first tool 10 by the jack 50 in a state where the first tool 10 is temporarily fixed.SELECTED DRAWING: Figure 5

Description

TECHNICAL FIELD The present invention relates to a bending method and a jig used therein for bending a reinforcing bar embedded in a pre-placed part of a reinforced concrete structure frame at an arbitrary point of the extended portion at a construction site of a reinforced concrete structure.

BACKGROUND ART In a reinforced concrete structure under construction, various reinforcing bars such as main reinforcing bars, wall reinforcing bars, anchor reinforcing bars, and insert reinforcing bars are embedded in pre-placed concrete. At joints between foundations and piles where the reinforcing bars are overcrowded and large-diameter reinforcing bars are intricately arranged, if the reinforcing bars exposed from the concrete joint face interfere with the reinforcing bars placed in the post-placed part, bend the main reinforcing bars of the pile. Shift work is required.

Such bending work is usually performed manually by a reinforcing bar worker using a long bending tool that applies the principle of a lever, as disclosed in Patent Document 1. However, when bending is performed manually using a bending tool, it is not easy to work in a narrow space, and it is difficult to bend large-diameter pile main bars and high-strength reinforcing bars. Moreover, since it is not easy to manually secure a predetermined curvature, a great deal of time and labor is required.

Patent documents 2 and 3 disclose reinforcing bar bending apparatuses using hydraulic cylinders in order to reduce such work. The reinforcing bar bending device disclosed in Patent Document 2 is a device for mainly bending auxiliary reinforcing bars (for example, stirrups) arranged around main reinforcing bars, and is rotated by a fitting recess formed in a body frame and a drive cylinder. It has a powered bending arm. By fixing the main reinforcement to the fitting recess on the body frame and rotating the bending arm on which the auxiliary reinforcement is arranged through the driving cylinder, the auxiliary reinforcement can be easily bent around the main reinforcement. However, the application of the reinforcing bar bending device disclosed in Patent Document 1 is limited to auxiliary reinforcing bars, and it cannot be used when there is no object (main reinforcing bars in Patent Document 1) to which the body frame is to be fixed.

Further, the reinforcing bar bending device disclosed in Patent Document 3 includes a hydraulic piston that slides along the arrangement direction of the reinforcing bar, a rod that adjusts the installation height of the hydraulic piston, and a protrusion of the hydraulic piston that rotates. , and a bending arm for bending the rebar. According to the reinforcing bar bending device with such a configuration, the height position of the device itself is maintained by the rod and the hydraulic piston can be used in the vertical direction, so workability is good and the labor of the operator is reduced. can do. However, since the bending arm is arranged in a state of being shifted with respect to the housing that constitutes the main body of the device, and the bending arm is rotated by the piston accommodated in the housing, the structure becomes complicated. end up

Japanese Utility Model Laid-Open No. 04-113112 JP-A-11-114631 JP-A-09-029345

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a method for bending a reinforcing bar, and a jig used therein, which can reduce the labor, time, and labor involved in bending the reinforcing bar extending from the joint surface by a simple method. and

A reinforcing bar bending method according to the present invention for achieving the above object is a reinforcing bar bending method for bending a reinforcing bar extending from a joint surface of pre-placed concrete, wherein a grip part for gripping the reinforcing bar is provided. Using a jig and a pressing jack, the gripping portion is set at a predetermined position of the reinforcing bar to temporarily fix the jig, and in a state where the jig is temporarily fixed, the end portion of the jig or the reinforcing bar is pressed by the jack.

Further, in the reinforcing bar bending method having the above characteristics, the jig has a gripping portion at one end and a pressing portion at the other end, and is temporarily fixed to the reinforcing bar by the jack placed on the joint surface. and pressing the pressing portion of the jig. When such a method is adopted, the jig and the jack can be separated, so that the jig can be made smaller and simpler.

Further, in the method for bending a reinforcing bar having the above characteristics, the jig has holding portions at both ends and a housing portion for storing the jack at the center portion, and after the jack is stored in the housing portion, the It is characterized in that the reinforcing bar is pressed in the cross direction by the jack while the jig is temporarily fixed to the reinforcing bar. When such a method is employed, since the jack can be interposed in the jig, it is possible to quickly perform setup from temporary fixing of the jig to the reinforcing bar to bending of the reinforcing bar.

Further, a jig for achieving the above object is a jig used for bending a reinforcing bar, which is provided at one end and has a gripping portion having a U-shaped recess for gripping the reinforcing bar, and is provided at the other end, and a pressing portion that is pressed by a jack.

Further, in the jig having the characteristics described above, the pressing portion is configured by a curved surface having a predetermined curvature. With such characteristics, it is possible to obtain a constant pressing state even if the contact angle between the pressing portion of the jig and the ram of the jack changes.

Further, a jig for achieving the above object is a jig used for bending a reinforcing bar, comprising a housing portion for accommodating a jack, and a U-shaped housing provided at both longitudinal ends of the housing portion for holding the reinforcing bar. and a grip portion having a recess, wherein a side wall of the housing portion is provided with an opening through which the ram of the jack protrudes.

Further, a jig for achieving the above object is a jig used for bending a reinforcing bar, which includes a gripping portion having a U-shaped concave portion for gripping the reinforcing bar, and a direction in which the reinforcing bar is gripped by the gripping portion. a jack chair for arranging a jack so as to discharge the ram in a direction; a reaction force receiver that connects the holding part and the jack chair and receives a reaction force when the jack presses the reinforcing bar; characterized by having

According to the reinforcing bar bending method having the characteristics described above, the reinforcing bar extending from the joint surface can be bent by a simple method using a simple jig and a jack. In addition, since the reinforcing bar can be bent with a predetermined curvature simply by adjusting the force of the jack, it is possible to reduce the labor, time, and labor involved in bending the reinforcing bar. Furthermore, by using a hydraulic jack, it is possible to handle bending of high-strength and large-diameter reinforcing bars.

It is a figure which shows the side surface structure of a 1st jig. It is a figure which shows the planar structure of a 1st jig. It is a figure which shows the state which temporarily fixed the 1st jig|tool to the reinforcing bar made into bending object. It is a figure which shows the state which set the jack with respect to the 1st jig temporarily fixed to the reinforcing bar made into bending object. It is a figure which shows the state which operated the jack, pushed up the 1st jig|tool, and bent the reinforcing bar. It is a side view which shows the application form of a 1st jig. It is a figure which shows the right side surface structure of a 2nd jig. It is a figure which shows the front structure of a 2nd jig. It is a figure which shows the planar structure of a 2nd jig. It is a figure which shows the state which temporarily fixed the 2nd jig|tool which set the jack to the reinforcing bar made into bending object. It is a figure which shows the state which operated the jack set to the 2nd jig, and bent the reinforcing bar. It is a figure which shows the side surface structure of a 3rd jig. It is a figure which shows the planar structure of a 3rd jig. It is a figure which shows the state which temporarily fixed the 3rd jig|tool which set the jack to the reinforcing bar made into bending object. It is a figure which shows the state which operated the jack set to the 3rd jig, and bent the reinforcing bar.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of a reinforcing bar bending method and a jig according to the present invention will be described in detail with reference to the drawings. It should be noted that the embodiment shown below is only a part of the present invention, and as long as the effect is exhibited, even if a part of the method and a part of the configuration of the jig are changed, the embodiment of the present invention can be applied. can be regarded as a department. In the following embodiments, the reinforcing bars to be bent are assumed to be reinforcing bars (for example, pile main bars) extending from the joint surface of pre-placed concrete.

[First embodiment]
[First jig]
First, with reference to FIGS. 1 and 2, the configuration of a jig (hereinafter referred to as a first jig 10) used in the reinforcing bar bending method according to the first embodiment will be described. In the drawings, FIG. 1 is a diagram showing the side construction of the first jig, and FIG. 2 is a diagram showing the same plane construction. The first jig 10 has a gripping portion 12 provided at one end and a pressing portion 14 provided at the other end. The gripping portion 12 is an element that plays a role of gripping the reinforcing bar 100 to be bent, and has a U-shaped concave portion 12a along the direction of gripping the reinforcing bar 100 (the direction in which the reinforcing bar 100 passes). The gripping portion 12 has a predetermined length (for example, about 80 mm to 100 mm) along the formation direction of the recess 12a in order to stably grip the reinforcing bar 100. As shown in FIG.

The pressing portion 14 is an element pressed by a ram 52 of a jack 50 whose details will be described later. In the case of the first jig 10, a pressing portion 14 is provided at an end portion of a plate member extending in a direction intersecting the extending direction of the recess 12a starting from one side wall of the U-shape forming the recess 12a of the grip portion 12. It is In the present embodiment, the pressing force is applied along the arrangement direction of the reinforcing bars 100 with respect to the grasping portion 12 . For this reason, the pressing portions 14 are provided at both ends of the plate member in the width direction (the direction indicated by the arrow a). By providing the pressing portions 14 at both ends, it is possible to arrange the pressing portions 14 on the joint surface 110 side even when the direction of the concave portion 12a in the grip portion 12 is reversed.

He is trying to comprise the press part 14 with a curved surface with a predetermined curvature in this embodiment. By configuring the pressing portion 14 in such a manner, the contact between the jack 50 and the ram 52 becomes a point or a line. Therefore, even if the contact angle between the pressing portion 14 and the ram 52 changes when the reinforcing bar 100 is bent by pressing, the contact state between the two can be kept constant.

In the first jig 10 shown in FIG. 1, a through hole 14a is formed in a plate surface of a plate member that constitutes the pressing portion 14. As shown in FIG. By forming the through hole 14a, the weight of the first jig 10 can be reduced, and the first jig 10 can be used as a handle for fitting the reinforcing bar 100 or the jack 50 to the first jig 10. FIG.

[Bending method]
Next, a method for bending the reinforcing bar 100 using the first jig 10 configured as described above will be described. First, as shown in FIG. 4, the first jig 10 is temporarily fixed at a predetermined position of the reinforcing bar 100 extending from the joint surface 110 of concrete. Here, the position where the first jig 10 is temporarily fixed is the position where the jack 50 enters between the lower end portion (pressing portion 14 ) of the first jig 10 and the joint surface 110 , and the lower end portion of the grip portion 12 . (The end portion of the reinforcing bar 100 on the side of the proximal end) may be located at a position closer to the distal side than the position where the reinforcing bar 100 is desired to be bent.

Temporary fixation of the first jig 10 is performed by inserting the reinforcing bar 100 along the concave portion 12a forming the grip portion 12 of the first jig 10 . Since the reinforcing bar 100 used for reinforcing concrete structures is a deformed steel bar, its surface is provided with convex knots at predetermined intervals. Since one side wall of the concave portion 12a forming the grip portion 12 is provided with a plate member forming the pressing portion 14, the grip portion 12 inclines toward the pressing portion 14 in the no-load state. becomes. For this reason, the end 12b2 and the end 12b4 of the grip portion 12 come into contact with the reinforcing bar 100, and are caught by the knots, preventing them from coming off.

Next, as shown in FIG. 4, a jack 50 (for example, a hydraulic jack) is arranged between the pressing portion 14 and the joint surface 110 that constitute the first jig 10, and the pressing portion 14 can be pressed by a ram 52. state. When the jack 50 is operated in such a state and the ram 52 is pushed up (projected) to apply a pressing force to the pressing portion 14, the pressing portion 14 is lifted by the ram 52, and the end portion 12b1 of the grip portion 12 and the end portion 12b1 of the grip portion 12 are separated from each other. The portion 12 b 3 comes into contact with the reinforcing bar 100 . The ends 12 b 1 and 12 b 3 of the grip portion 12 are respectively hooked on the nodes of the reinforcing bar 100 , and the first jig 10 is positioned with respect to the reinforcing bar 100 .

After the first jig 10 is positioned, the ram 52 of the jack 50 is further pushed up, so that the end portion 12b3 of the first jig 10 becomes the fulcrum, the end portion 12b1 becomes the point of action, and the pressing portion 14 becomes the force point. A load is applied in the b direction.

As the reinforcing bar 100 bends, the inclination of the first jig 10 also increases. There is no change in (line contact), and it is possible to press to a desired bending angle. After imparting a desired bending angle (curvature) to the reinforcing bar 100, the jack 50 and the first jig 10 are removed from around the reinforcing bar 100, thereby completing the bending of the reinforcing bar 100. FIG.

[effect]
According to such a method for bending the reinforcing bar 100 , the reinforcing bar 100 can be bent only by using a simple jig (first jig 10 ) and the jack 50 . Therefore, it is possible to reduce the labor, time, and effort required to bend the reinforcing bar 100 .

Further, a predetermined curvature can be given to the reinforcing bar 100 simply by adjusting the force of the jack 50 (including adjusting the degree of elongation of the ram 52 and how to apply the load).

Furthermore, since the bending load is applied using hydraulic pressure, it is possible to cope with the bending of the reinforcing bar 100 with high strength and large diameter.

[application]
In the above embodiment, it is described that the work is performed with the jack 50 arranged on the joint surface 110 . However, when carrying out the reinforcing bar bending method according to the present invention, a roller may be arranged between the lower end of the jack 50 and the joint surface 110 (not shown). The jack 50 itself also rotates when it receives a load during jacking up, and the angle formed by the pressing portion 14 and the ram 52 can be made small, and the loss of the load applied to the pressing portion 14 can be reduced. Because it becomes

6, the first jig 10 may be tilted so as to form an angle .theta. This is because efficient construction is possible when it is desired to bend the reinforcing bar 100 to a large extent.

[Second embodiment]
[Second Jig]
Next, jigs used in the method for bending reinforcing bars according to the second embodiment will be described with reference to FIGS. 7 to 9. FIG. In the drawings, FIG. 7 is a view showing the configuration of the right side of the second jig, FIG. 8 is a view showing the same front configuration, and FIG. 9 is a view showing the same plane configuration. A jig according to the present embodiment (hereinafter referred to as a second jig 10A) has a grip portion 12 and a housing portion 16. As shown in FIG. The gripping portions 12 are elements that play a role of gripping the reinforcing bar 100 to be bent, and are provided at both ends in the longitudinal direction of the second jig 10A so as to sandwich the housing portion 16, which will be described later in detail. The gripping portion 12 has a U-shaped concave portion 12a in the same manner as the gripping portion 12 of the first jig 10, and the pair of gripping portions 12 have the concave portions 12a oriented in the same direction (longitudinal direction of the second jig 10A). side). This is because when the reinforcing bar 100 extending linearly is bent, it is inserted into the paired concave portions 12a from a certain direction.

The housing part 16 is an element responsible for holding the jack 50 . Specifically, it consists of a housing main body 16a made of a square steel pipe or the like, and reinforcing members 16b arranged around the housing main body 16a. A side surface of the housing body 16a is provided with a first opening 16a1 for inserting the jack 50 therein. A second opening 16a2 for projecting the ram 52 of the jack 50 is provided on the side surface of the housing main body 16a on which the grip portion 12 extends.

As can be seen from the drawings, the opening direction of the recessed portion 12a of the grip portion 12 is on the right side, whereas the second opening 16a2 for projecting the ram 52 of the jack 50 is on the front side. is open to Therefore, the reinforcing bar 100 pressed by the ram 52 can be kept held by the grasping portion 12 .

[Bending method]
Next, a method for bending the reinforcing bar 100 using the second jig 10A configured as described above will be described. First, as shown in FIG. 10, the jack 50 is housed inside the housing portion 16 (inside the housing main body 16a). After that, the second jig 10A is temporarily fixed at a predetermined position of the reinforcing bar 100 extending from the joint surface 110 of the concrete. Temporarily fixing the second jig 10A involves inserting the reinforcing bars 100 to be bent into the concave portions 12a of the pair of gripping portions 12 provided in the second jig 10A and bringing the rams 52 of the jacks 50 into contact with the sides of the reinforcing bars 100. You should do it like this.

After temporarily fixing the second jig 10</b>A, the jack 50 is operated to push out the ram 52 , thereby bending the reinforcing bar 100 . At this time, the pair of gripping portions 12 serve as fulcrums, and the contact portion of the ram 52 serves as the force and action point.

[effect]
Even with such a method for bending the reinforcing bar 100, the reinforcing bar 100 can be bent only by using a jig (second jig 10A) with a simple configuration and the jack 50. Labor can be reduced.

Moreover, a predetermined curvature can be given to the reinforcing bar 100 only by adjusting the force of the jack 50 . Furthermore, since the bending load is applied using hydraulic pressure, it is possible to cope with the bending of the reinforcing bar 100 with high strength and large diameter.

[Third Embodiment]
[Third Jig]
Next, a jig used in the method for bending reinforcing bars according to the third embodiment will be described with reference to FIGS. 12 and 13. FIG. In the drawings, FIG. 12 is a diagram showing the side construction of the third jig, and FIG. 13 is a diagram showing the same plane construction. The third jig 10B has a grip portion 12, a reaction force receiver 18, and a jack chair 20. As shown in FIG. The grip part 12 is an element for gripping the reinforcing bar 100 to be bent, like the first jig 10 and the second jig 10A described above. As for the configuration, it is sufficient that it has a U-shaped concave portion 12a like the first jig 10 and the second jig 10A.

The reaction force receiver 18 is an element for supporting the bottom of the jack 50 and receiving the reaction force when the reinforcing bar 100 is pressed. The reaction force receiver 18 is formed by a steel material (horizontal steel material 18a) extending from the side wall of the recess 12a forming the grip part 12 and a steel material (vertical steel material 18b) provided so as to be perpendicular to the horizontal steel material 18a. In the example shown in FIGS. 12 and 13, both the horizontal steel material 18a and the vertical steel material 18b are T-shaped steel materials.

The jack chair 20 is an element for adjusting the pressing position of the reinforcing bar 100 by the jack 50 , that is, the mounting position of the jack 50 . In this embodiment, it is made of a plate material formed in an L shape, and one plate surface is brought into contact with the vertical steel material 18b that constitutes the reaction force receiver 18, and the other plate surface is parallel to the horizontal steel material 18a. are arranged as follows. Laying the jack 50 on the other plate surface of the jack chair 20 arranged in this manner enables the jack 50 to extend the ram 52 parallel to the horizontal steel member 18a. Further, the height of the jack 50 can be adjusted by positioning one plate surface with respect to the vertical steel material 18b.

[Bending method]
Next, a method for bending the reinforcing bar 100 using the third jig 10B configured as described above will be described. First, the jack 50 is set on the jack chair 20 as shown in FIG. Next, the grip portion 12 of the third jig 10B with the jack 50 set is set on the reinforcing bar 100 to be bent.

After setting the grip part 12 on the reinforcing bar 100, the jack 50 is operated to extend the ram 52, as shown in FIG. As a result, the reinforcing bar 100 is pressed by the ram 52 of the jack 50 fixed to the reinforcing bar 100 via the grip portion 12 . When the rigidity of the reaction force receiving of the third jig 10B is higher than the bending strength of the reinforcing bar 100, the reinforcing bar is pressed by the ram 52 and bent.

[effect]
Even with such a method of bending the reinforcing bar 100, the reinforcing bar 100 can be bent only by using a jig with a simple configuration (the third jig 10B and the jack 50). can be reduced.

Moreover, a predetermined curvature can be given to the reinforcing bar 100 only by adjusting the force of the jack 50 . Furthermore, since the bending load is applied using hydraulic pressure, it is possible to cope with the bending of the reinforcing bar 100 with high strength and large diameter.

In the above-described embodiment, the reinforcing bars 100 to be bent are all reinforcing bars extending from the joint surface 110 when constructing the structure. can be applied.

Reference Signs List 10: first jig, 10A: second jig, 10B: third jig, 12: grip portion, 12a: concave portion, 12b1, 12b2, 12b3, 12b4: end portion, 14......pressing portion 14a......through hole 16......housing part 16a......housing main body 16a1......first opening 16a2......second opening 16b...... Reinforcing member 18 Reaction force receiver 18a Horizontal steel 18b Vertical steel 20 Jack chair 50 Jack 52 Ram 100 Reinforcing bar 110…… Pitch joint surface.

Claims (7)

A reinforcing bar bending method for bending a reinforcing bar extending from a joint surface of pre-placed concrete, comprising:
Using a jig having a gripping portion for gripping the reinforcing bar and a jack for pressing,
Temporarily fixing the jig by setting the gripping portion at a predetermined position of the reinforcing bar,
A method for bending a reinforcing bar, comprising pressing an end portion of the jig or the reinforcing bar with the jack while the jig is temporarily fixed. The jig has a gripping portion at one end and a pressing portion at the other end,
2. The reinforcing bar bending method according to claim 1, wherein the pressing portion of the jig temporarily fixed to the reinforcing bar is pressed by the jack placed on the joint surface. The jig has holding portions at both ends and a housing portion for accommodating the jack in the center,
After the jack is accommodated in the housing portion, in a state in which the jig is temporarily fixed to the reinforcing bar,
2. The method of bending a reinforcing bar according to claim 1, wherein the jack presses the reinforcing bar in a cross direction. A jig used for bending reinforcing bars,
a gripping portion provided at one end and having a U-shaped recess for gripping the reinforcing bar;
and a pressing part provided at the other end and pressed by a jack. 5. The jig according to claim 4, wherein said pressing portion is formed of a curved surface having a predetermined curvature. A jig used for bending reinforcing bars,
a housing portion that houses the jack;
holding portions provided at both ends in the longitudinal direction of the housing portion and having U-shaped concave portions for holding reinforcing bars;
A jig, wherein a side wall of the housing portion is provided with an opening through which the ram of the jack protrudes. A jig used for bending reinforcing bars,
a gripping portion having a U-shaped recess for gripping the reinforcing bar;
a jack chair for arranging the jack so as to discharge the ram in a direction intersecting with the gripping direction of the reinforcing bar by the gripping part;
A jig, comprising: a reaction force receiver that connects the holding part and the jack chair and receives a reaction force when the jack presses the reinforcing bar.

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