JPH11124958A - Rebar joint structure - Google Patents

Abstract

(57) [Problem] To provide a joint structure which has a large allowable range of axial deviation between rebars to be connected and can be connected without bending the connecting portion of the rebar even if a large axial deviation occurs. thing. A thread is formed at least at an end of a reinforcing bar, and the reinforcing bar is inserted bidirectionally into a steel pipe having a flat cross section, that is, a joint fitting, and a first end of each reinforcing rod protruding from the joint fitting is provided. The second nuts 12 and 22 were screwed into the respective rebars in such an arrangement that the first nuts and the fittings were clamped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rebar joint structure.

[0002]

2. Description of the Related Art For the purpose of seismic reinforcement, a reinforcing method of winding a reinforcing bar around an existing concrete pier has been carried out. In this reinforcing method, a reinforcing bar is added vertically along a pier to fix the reinforcing bar. A hole is drilled in the foundation concrete, and the lower end of the reinforcing bar is inserted into this hole and fixed with mortar or a resin adhesive. At this point, when drilling the foundation concrete, it is impossible to drill the hole at a predetermined position if trying to avoid the existing reinforcing bars so as not to damage the existing reinforcing bars, resulting in misalignment between the axis of the additional reinforcing bars and the fixing holes. There was a problem that occurred. In addition, in order to suppress the increase in cross section and weight of the pier due to seismic reinforcement, it is preferable that the additional rebar is brought as close as possible to the surface of the existing pier, while the drilling machine is made to approach the existing pier. There is a limit to the range that can be made, and it has been difficult to drill holes at predetermined positions in the foundation concrete.

[0003] In addition, in the case of seismic reinforcement, a lap joint is not allowed to be used as a joint for an additional reinforcing bar, and therefore a mechanical joint, a press-fit joint, and a weld joint are used. However, these joints have a small tolerance of several mm for the displacement of the axis of the connecting rebar, so that if the rebar fixed to the foundation concrete is displaced, the connection work of the rebar becomes difficult. There is. For example, in the case of a screw joint in which a threaded bar is screwed and connected to a lock nut from both sides, or a joint in which a male screw or a female screw is formed at the tip of a reinforcing bar to be joined, a permissible range of axial misalignment is provided. Is extremely small, about several mm. In addition, a splice sleeve joint that inserts the tip of a reinforcing bar into a sleeve and fills it with high-strength non-shrink mortar, or a joint that cold-presses a sleeve with a reinforcing bar inserted by a press machine, is better than the screw joint. Although the allowable range for the axial center deviation is large, the positional deviation of several centimeters is not acceptable.

[0004] As described above, it has been proposed to bend the reinforcing bar fixed to the foundation concrete and to reinforce the bent portion with the reinforced concrete when the rebar is misaligned with the axis. However, in this case, it is necessary to bend the rebar corresponding to the axial misalignment in advance, and measuring and processing the amount of bending for each individual rebar takes a lot of time and the work becomes complicated. was there.

[0005]

SUMMARY OF THE INVENTION The present invention focuses on the above-mentioned drawbacks of the prior art and attempts to solve them. The problem is that the allowable range of the axial misalignment of the rebars to be connected is large. Another object of the present invention is to provide a joint structure capable of connecting without bending a connecting portion of a reinforcing bar even if a large axial center shift occurs.

[0006] In the above-mentioned prior art and the description of the problem, in particular, the joint of the reinforcing bar in the method of reinforcing the existing pier has been exemplified, but an object of the present invention is to provide a joint structure of the reinforcing bar. The joint structure is not limited to the existing pier reinforcement method.

[0007]

According to the present invention, according to the first aspect of the present invention, a screw thread is formed at least at an end portion of the reinforcing bar, and the reinforcing bar is inserted into a flat cross-section tube from both directions, and protrudes from the tube. Further, there is provided a joint structure of a reinforcing bar, wherein a first nut is screwed into a tip of each of the reinforcing bars and locked to the pipe. Here, it is preferable that a second nut is screwed to each of the rebars in such an arrangement that the tube is sandwiched between the first nuts. By providing the second nut in this way, it is possible to prevent the tube disposed at the joint portion of the reinforcing bar from being unstable and slightly moving.

In the joint structure of a reinforcing bar according to the present invention, a mechanical joint is formed by inserting a reinforcing member from both sides of a tubular body having a flat cross section and screwing a first nut to each end thereof. Therefore, even if the rebars are displaced from each other at the center of the axis, it is possible to firmly connect the rebars with the longitudinal length of the cross section of the tube as a limit. Therefore, in the conventional joint, the allowable range of the axial center misalignment was as very small as about several mm. However, in the present invention, the axial center is adjusted by using a tube in which the longitudinal length of the tube body cross section is appropriately adjusted. It is possible to easily connect rebars having a displacement ranging from several cm to several tens cm without bending.

According to the present invention, in the third aspect, a reinforcing bar having a thread at least at an end portion, a pipe for penetrating the reinforcing bar in both directions, and a screw at a tip of each of the reinforcing bars protruding from the pipe. A joint structure for a reinforcing bar, comprising: a first nut to be fitted; and a plate sandwiched between each of the first nuts and both ends of the tubular body and formed with a long hole through which the reinforcing bar can pass. Is provided. Here, it is preferable that the length of the long hole of the plate is larger than the maximum inner dimension of the tube. Further, it is preferable that a second nut is screwed to each of the rebars in such an arrangement that the tube is sandwiched between the first nut and the respective plates via the respective plates. By providing the second nut in this way, it is possible to prevent the tube body and each plate body arranged at the joint portion of the reinforcing bar from being unstablely moved slightly.

In the joint structure according to the third aspect of the present invention, the plate body having the long hole through which the reinforcing bar can penetrate is sandwiched between each first nut and both ends of the tube body. The shape is not limited to a cross section, and a tubular body having a circular or square cross section can be used. And in this joint structure,
A few centimeters of misalignment of the axis centered on the length of the long hole of the plate
It has become possible to easily and firmly connect rebars ranging from about 10 cm to about 10 cm without bending.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments will be described below with reference to the accompanying drawings, but the present invention is not limited to these embodiments. FIG.
FIG. 2 is a side view of the joint structure of the present invention viewed from the side, and FIG.
FIGS. 2A and 2B are plan views of a joint structure using joint fittings having different shapes (a tubular body having a flat cross section) when viewed from above, and FIG.
FIG. 2C is a plan view for explaining an allowable range of a positional shift between the axes in the joint structure of FIG. Further, FIG.
FIG. 3 (a) is a side view in which only the joint portion is enlarged to show a joint structure in which a plate is held between the joint fitting and the first nut, and FIG. 3 (b) is FIG. 3 (a). Break line IIIb-II at
It is sectional drawing which followed Ib. FIG. 1 shows an example in which the joint structure of a reinforcing bar of the present invention is applied to seismic reinforcement of an existing pier 30. Here, in order to reinforce the pier 30, a plurality of reinforcing bars 10 are vertically arranged on the outer periphery of the pier 30. The foundation concrete 33 such as built-in and footing is drilled, and the fixing reinforcing bar 20 is inserted into the hole, and the reinforcing reinforcing bar 10 and the fixing reinforcing bar 20 are connected with the joint fitting 1 and the end nuts 11 and 21. Further, a band reinforcing bar 32 is wound around the reinforcing bar 10 and the fixing bar 20, and the reinforcing bar 10, the fixing bar 20 and the band reinforcing bar 32 are covered with a covering material 31 such as concrete.

Hereinafter, the joint structure of the present invention will be further described. Screw reinforcing bars are used as the reinforcing bars 10 and the fixing bars 20, and the ends of the reinforcing bars 10 and the fixing bars 20 are inserted into the fitting 1 from both sides. The end nuts 11 and 21 and the fixing nuts 12 and 22 are screwed together so as to clamp the fitting 1, and the interior of the fitting 1 is filled with a filler such as mortar.

The joint fitting 1 is formed of a steel pipe having a flat cross section such as an oval shape in FIG. 2A, a rectangular or elliptical shape (not shown) in FIG. 2B, and a steel pipe. End nuts 11 and 21 and fixing nuts 12 and 2
2 which has a rigidity enough to withstand the pinching of the reinforcing member 2 and a strength capable of withstanding the bending moment transmitted from the reinforcing reinforcing bar 10 and the fixing reinforcing bar 20. End nut 1
1, 21 and the fixing nuts 12, 22 are
And, when it is screwed into the fixing reinforcing bar 20, the one having a size that can be securely locked to the end of the joint fitting 1 without passing through the inside of the joint fitting 1 is used. That is,
As shown in FIG. 2, the inner dimension d in the width direction of the joint fitting 1
Nuts having larger outer dimensions D are used as the end nuts 11 and 21 and the fixing nuts 12 and 22.

In the above-described joint structure of the present invention, as shown in FIG. 2C, the axis of the reinforcing reinforcing bar 10 and the fixing reinforcing bar 20 depends on the longitudinal length of the cross section of the fitting 1. The maximum allowable value b of the center displacement is determined. The maximum allowable value b of the axis deviation of the reinforcing bar is much larger than the allowable range of several mm of the conventional joint, and therefore, the axis deviation is several cm to
It has become possible to easily connect rebars up to about 10 cm or more without bending. Further, since the end nuts 11 and 21 and the fixing nuts 12 and 22 are screwed to the reinforcing reinforcing bar 10 and the fixing reinforcing bar 20, respectively, as shown in FIG.
In the case of 0, the axis is required to be separated by a predetermined length a or more.

Next, with reference to FIGS. 3A and 3B, a joint structure different from those in FIGS. 1 and 2 will be described. 3 (a) and 3 (b), the difference from the joint structure of FIGS.
4, the cross-sectional shape of the pipe used for the joint fitting 2 is not limited to a flat shape by the plates 3, 4.
As shown in (b), it is possible to have a cylindrical shape or a square (not shown). That is, the plates 3 and 4
As shown in FIG. 3B, elongated holes 4a through which the reinforcing steel bars 10 and the fixing reinforcing bars 20 can be formed are formed, and the length of the elongated holes is determined by the diameter of the joint fitting 2 or the maximum length. Be larger than the inner dimension. Then, the plate members 3 and 4 are arranged so as to abut on both ends of the joint fitting 2, and the reinforcing reinforcing bar 1 is provided.
0 and the fixing rebar 20 are inserted into the long holes of the two plates 3 and 4 and the inside of the joint fitting 2, and the end nuts 11 and 21 are screwed and fixed to the tips of the reinforcing rebar 10 and the fixing rebar 20. The nuts 12 and 22 are tightened with the end nuts 11 and 21 in such a manner as to clamp the joint fitting 2 via the plates 3 and 4 respectively. In addition, also in the joint structure shown in FIG. 3, it is possible to connect the rebars with the misalignment of the axial center without bending, with the limit of the length of the long holes of the plates 3 and 4. Became.

[Brief description of the drawings]

FIG. 1 is a side view of a joint structure of a rebar according to the present invention as viewed from the side.

FIGS. 2A to 2C are plan views of a joint structure using joint fittings having different shapes.

FIG. 3A is an enlarged side view showing a joint structure in which a plate is sandwiched between a joint fitting and a first nut, and FIG. 3B is an enlarged side view of FIG.
FIG. 3 is a cross-sectional view taken along line IIIb-IIIb in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Joint fitting (tube body of a flat cross section) 2 Joint fitting (tube body) 3 Plate 4 Plate 4a Slot 10 Reinforcing reinforcing bar (rebar) 20 Reinforcing bar (rebar) 11, 21 End nut (first nut) ) 12,22 Fixing nut (second nut)

Claims (4)

[Claims] A thread is formed at least at an end portion of a reinforcing bar, and the reinforcing bar is inserted bidirectionally into a tube having a flat cross section, and a first nut is attached to a tip of each of the reinforcing bars protruding from the tube. A joint structure for a reinforcing bar, which is screwed and locked to the tube. 2. A joint structure for a reinforcing bar according to claim 1, wherein a second nut is screwed into each of said first reinforcing nuts so as to clamp said first nut and said tubular body. 3. A rebar having a thread formed at least at an end thereof, a pipe body penetrating the rebar bidirectionally, and a first nut screwed into a tip of each rebar projecting from the pipe body. ,
A joint structure for a reinforcing bar, comprising a plate body sandwiched between each of the first nuts and both ends of the tubular body and having a long hole formed through the reinforcing bar. 4. The rebar according to claim 3, wherein a second nut is screwed into each of said rebars in such a manner that said first nut and said tube are sandwiched through said respective plates. Rebar joint structure.