JP2021004515A - Reinforcement junction structure - Google Patents

Abstract

To provide a reinforcement junction structure which facilitates junction between reinforcements, surely transmits a force between a concrete and a reinforcement, and can suppress an increase in a diameter of a joint part.SOLUTION: A reinforcement junction structure includes a first reinforcement body 13 of a first reinforcement 11 extending in one direction, a second reinforcement body 13 of a second reinforcement 12 that is arranged on an extension line of the first reinforcement body 13 and has one end 12a arranged so as to face one end 11a of the first reinforcement body 13 of the first reinforcement 11, a diameter expanding plate 15 that is provided to extend to the outside in a radial direction on one ends 11a and 12a of the first reinforcement body 13 and the second reinforcement body 13 and has a plurality of through holes 16 arranged at intervals in a circumferential direction, and a connection member 20 which inserts the diameter expanding plate 15 of the first reinforcement body 13 and the diameter expanding plate 15 of the second reinforcement body 13 into the through holes 16 of both of the diameter expanding plates 15 in a state where the diameter expanding plates 15 are abutted to each other.SELECTED DRAWING: Figure 1

Description

The present invention relates to a reinforcing bar joint structure.

Conventionally, as a joint structure for joining reinforcing bars embedded in concrete, a lap joint, a gas pressure welded joint, a mechanical joint, a welded joint and the like are known. However, in the case of a lap joint, for example, since the force is transmitted through the concrete, the tensile force cannot be sufficiently transmitted when the reinforcing bar diameter becomes large. Further, in the case of a gas pressure welding joint, skillful skill is required to gas pressure welding the reinforcing bars, and the number of workers is limited. In addition, in bad weather, gas pressure welding cannot be performed, which leads to a longer construction period. In the case of mechanical joints, the finished diameter is large.
To solve these problems, it is desired that the reinforcing bars are easily joined to each other, the force is surely transmitted between the concrete and the reinforcing bars, and the diameter of the joint portion is suppressed from becoming large.

On the other hand, for example, Patent Document 1 discloses a configuration in which the end faces of reinforcing bars with a diameter-expanding portion having a diameter-expanding portion at the ends face each other and the enlarged-diameter portion is housed in a hollow portion of a joint member for reinforcing bars. ing. In such a configuration, the enlarged diameter portion has an end face inclined with respect to a plane orthogonal to the axis perpendicular to the axis of the reinforcing bar. In the hollow portion of the joint member for reinforcing bars, one or both of the reinforcing bars with an enlarged diameter portion are axially rotated to stretch the end faces. As a result, the enlarged diameter portions of both reinforcing bars try to separate from each other in the hollow portion, and the loosened portions in the axial direction are eliminated.

Japanese Unexamined Patent Publication No. 2010-255201

However, in the configuration as disclosed in Patent Document 1, after the enlarged diameter portions provided at the ends of the reinforcing bars with the enlarged diameter portion are opposed to each other and the enlarged diameter portions are housed in the hollow portions of the pair of reinforcing bar joint members. , It is necessary to rotate one or both of the reinforcing bars with enlarged diameter parts. When the reinforcing bar with the enlarged diameter portion interferes with other reinforcing bars, steel frames, etc., it may be difficult to rotate the reinforcing bar with the enlarged diameter portion, and there is room for further improvement.

The present invention has been made in view of the above circumstances, and it facilitates joining of reinforcing bars, reliably transmits force between concrete and reinforcing bars, and suppresses an increase in the diameter of a joint portion. It provides a possible reinforcing bar joint structure.

In order to achieve the above object, the present invention employs the following means.
That is, the reinforcing bar joining structure according to the present invention is arranged on the extension line of the first reinforcing bar main body extending in one direction and the first reinforcing bar main body, and one end thereof is arranged so as to face one end portion of the first reinforcing bar main body. The second reinforcing bar main body, the first reinforcing bar main body, and each one end portion of the second reinforcing bar main body are provided so as to extend outward in the radial direction, and have a plurality of through holes arranged at intervals in the circumferential direction. The diameter plate, the enlarged diameter plate of the first reinforcing bar main body, and the enlarged diameter plate of the second reinforcing bar main body are abutted against each other, and are inserted into the through holes of both of the enlarged diameter plates to expand the diameter. It is characterized by including a connecting member for connecting the diameter plates to each other.

In the reinforcing bar joining structure configured in this way, the reinforcing bars can be joined by the diameter-expanding plates that are abutted against each other and the connecting members that connect the diameter-expanding plates to each other. When joining the reinforcing bars, the connecting members may be inserted into the through holes formed in the enlarged diameter plates in a state where the enlarged diameter plates are abutted against each other to connect the enlarged diameter plates to each other. Even if other reinforcing bars or the like are present around the reinforcing bars, they do not interfere with the joining work. Further, since the enlarged diameter plates abut against each other, the force in the compression direction in which the reinforcing bars approach each other can be reliably transmitted. In addition, the connecting member that connects the enlarged diameter plates can reliably transmit the force in the tensile direction that separates the reinforcing bars from each other. Further, the diameter-expanding plates extending outward in the radial direction of the first reinforcing bar main body and the second reinforcing bar main body need only have a size (diameter dimension) for providing a connecting member to be inserted into the through hole in the radial direction. It is possible to prevent it from becoming excessively large.
Therefore, it is possible to easily join the reinforcing bars to each other and prevent the diameter of the joint portion from becoming large.

Further, in the reinforcing bar joining structure according to the present invention, the connecting member is a bolt having a screw shaft inserted from the through hole of one of the enlarged diameter plates to the through hole of the other enlarged diameter plate, and the other. It is preferable to include a nut mounted on the screw shaft of the bolt protruding from the through hole of the enlarged diameter plate.

In the reinforcing bar joining structure configured in this way, the reinforcing bars can be easily joined by connecting the enlarged diameter plates with bolts and nuts.

Further, in the reinforcing bar joining structure according to the present invention, at least one of the head of the bolt and the nut has a gap between the first reinforcing bar main body and the second reinforcing bar main body in the extension direction of the enlarged diameter plate. The first reinforcing bar main body, the second reinforcing bar main body, the enlarged diameter plate, and the connecting member are embedded in concrete.

In the reinforcing bar joint structure configured in this way, the bolts and nuts constituting the connecting member are fixed by being embedded by concrete to be driven later. Therefore, it is not necessary to fasten the bolt and nut with the specified tightening torque (the tightening torque when the bolt and nut are fully tightened), and the nut is manually tightened to the screw shaft of the bolt inserted through the through hole. Reinforcing bars can be joined to each other to a certain extent. Therefore, the joining work between the reinforcing bars can be easily performed.

According to the reinforcing bar joining structure according to the present invention, it is possible to easily join the reinforcing bars, reliably transmit the force between the concrete and the reinforcing bar, and suppress the diameter of the joint portion from becoming large. It becomes.

It is a figure which shows the structure of the joint part of the reinforcing bar to which the joining structure of the reinforcing bar which concerns on one Embodiment of this invention is applied. It is a perspective view which shows the 1st reinforcing bar and the 2nd reinforcing bar used for the joint structure of the said reinforcing bar. It is a side view of the 1st reinforcing bar and the 2nd reinforcing bar. It is the figure which looked at the joint part of the said reinforcing bar from one reinforcing bar side.

The joint structure of the reinforcing bar according to the embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a configuration of a reinforcing bar joint portion to which a reinforcing bar joint structure according to an embodiment of the present invention is applied.
As shown in FIG. 1, the reinforcing bar joint structure 1 of the present embodiment includes one end portion 11a of the first reinforcing bar 11 and a second reinforcing bar 11 in various structural materials 2 such as columns, beams, slabs, and walls constituting the structure. It has a structure for joining one end portion 12a of the reinforcing bar 12. The structural material 2 includes a first reinforcing bar 11 and a second reinforcing bar 12 joined to each other, and a concrete portion 3 provided so as to cover the first reinforcing bar 11 and the second reinforcing bar 12.

The first reinforcing bar 11 and the second reinforcing bar 12 are arranged on the same extension line. One end 12a of the second reinforcing bar 12 is arranged to face the one end 11a of the first reinforcing bar 11.

FIG. 2 is a perspective view showing the first reinforcing bar and the second reinforcing bar used in the joint structure of the reinforcing bars. FIG. 3 is a side view of the first reinforcing bar and the second reinforcing bar. FIG. 4 is a view of the joint portion of the reinforcing bar as viewed from one reinforcing bar side.
As shown in FIGS. 1 to 4, one end portion 11a of the first reinforcing bar 11 and one end portion 12a of the second reinforcing bar 12 have similar structures, respectively. The first reinforcing bar 11 and the second reinforcing bar 12 each have a reinforcing bar main body (first reinforcing bar main body, second reinforcing bar main body) 13 and an enlarged diameter plate 15.

The reinforcing bar main body 13 is made of round steel, deformed reinforcing bars, or the like, and extends in a predetermined direction. Examples of the reinforcing bar main body 13 include deformed steel bars (SD295A, SD295B, SD345, SD390, SD490), round steel (SR235, SR295), and high-strength reinforcing bars (USD385A, USD385B) defined by steel bars for reinforced concrete (JISG3112). USD980), or stainless steel rebar or epoxy resin coated rebar with improved durability can be used. The reinforcing bar diameter can be any diameter. If it is a deformed steel bar, it can be used for the names D10 to D51.

The diameter expansion plate 15 is provided at the end portion 13a of the reinforcing bar main body 13. The diameter-expanding plate 15 has a metal plate shape, and extends radially outward from the reinforcing bar main body 13 at one end 11a of the first reinforcing bar 11 and the one end 12a of the second reinforcing bar 12. In the present embodiment, the enlarged diameter plate 15 has a circular shape, for example, when viewed from the stretching direction of the reinforcing bar main body 13. Further, in the present embodiment, the diameter-expanding plate 15 has a reinforcing bar insertion hole 15h penetrating in the plate thickness direction (stretching direction of the reinforcing bar main body 13) of the diameter-expanding plate 15 in the central portion. The end portion 13a of the reinforcing bar main body 13 is inserted into the reinforcing bar insertion hole 15h and joined to the enlarged diameter plate 15.

In order to form the diameter-expanded plate 15, for example, the diameter-expanded plate 15 may be manufactured by hot-molding hot embedding. In the hot installation process, the end 13a of the reinforcing bar body 13 is heated by a heating device, the end surface of the reinforcing bar body 13 is pressed against the molding surface of the mold, and a compressive force in the axial direction is applied to the reinforcing bar body 13 by pressing. Compress the heating area. The heating region of the reinforcing bar main body 13 is plastically deformed so as to increase the outer diameter, and the enlarged diameter plate 15 is formed. In this case, the through holes 16 may be formed at the same time as the heat forming of the enlarged diameter plate 15. Further, the through hole 16 may be formed by drilling after the diameter-expanding plate 15 is heat-molded.

Here, the diameter-expanding plate 15 has high orthogonality with respect to the axial center of the reinforcing bar main body 13 so that the first reinforcing bar 11 and the second reinforcing bar 12 do not deviate from each other in the radial direction of the reinforcing bar main body 13. It is preferable to provide the above.

The outer diameter (diameter) of the enlarged diameter plate 15 can be determined according to the size and the number of connecting members 20, but it is preferably about 2.5 times the outer diameter of the reinforcing bar main body 13. It is preferable that both sides of the enlarged diameter plate 15 have improved surface accuracy.

The enlarged diameter plate 15 has a plurality of through holes 16. The plurality of through holes 16 are arranged at intervals in the circumferential direction centered on the reinforcing bar main body 13. Each through hole 16 is formed by penetrating the enlarged diameter plate 15 in the plate thickness direction.

As shown in FIG. 1, in the joint portion 5 to which the joint structure 1 of the reinforcing bars is applied, the first reinforcing bar 11 and the second reinforcing bar 12 are the enlarged diameter plate 15 of the first reinforcing bar 11 and the enlarged diameter plate of the second reinforcing bar 12. The 15s are joined by the connecting member 20 in a state of being abutted against each other. In the present embodiment, the connecting member 20 includes a bolt 21 and a nut 22.

The bolt 21 integrally has a screw shaft 21a having a male screw groove formed on the outer peripheral surface thereof and a head portion 21b provided at one end of the screw shaft 21a. In the bolt 21, the screw shaft 21a is inserted from the through hole 16 of the enlarged diameter plate 15 of the first reinforcing bar 11 into the through hole 16 of the enlarged diameter plate 15 of the second reinforcing bar 12. In the bolt 21, the tip of the screw shaft 21a is opposite to the diameter-expanding plate 15 of the second reinforcing bar 12 to the first reinforcing bar 11 side in a state where the head 21b is abutted against the diameter-expanding plate 15 of the first reinforcing bar 11. It protrudes to the side (right side in FIG. 1). The nut 22 is attached to the tip of the screw shaft 21a and abuts on the enlarged diameter plate 15 of the second reinforcing bar 12. The diameter-expanding plate 15 of the first reinforcing bar 11 and the diameter-expanding plate 15 of the second reinforcing bar 12 are connected by the connecting member 20 composed of the bolt 21 and the nut 22.
In the present embodiment, for example, when the reinforcing bar D35 of the steel type SD295 is used for the reinforcing bar main body 13, the tensile force can be sufficiently transmitted by using six M12 bolts of the strength category 8.8 as the bolts 21. it can.

The number and diameter of the bolts 21 to be used are determined so as to have rigidity equivalent to that of the base materials of the reinforcing bars 11 and 12. When the elastic modulus of the reinforcing bars 11 and 12 and the elastic modulus of the bolt 21 are the same, the total area of each bolt 21 and the area of the base material of the reinforcing bars 11 and 12 may be the same. When bolts 21 having elastic coefficients different from those of the reinforcing bars 11 and 12 are used, the required number and diameter are determined in consideration of the area and elastic modulus. In addition, the number, diameter, and strength of the bolts 21 are selected so that the bolts 21 do not break before the reinforcing bars 11 and 12 break.

Here, in normal bolt joining when it is not embedded in concrete or the like, parts such as nuts may suddenly come off or move when a repeated load or the like is applied. Therefore, it is necessary to tighten with an appropriate torque to apply a force to fix the nut. On the other hand, since the bolt 21 and the nut 22 of the present embodiment are embedded in the concrete 3c forming the concrete portion 3, the bolt 21 does not loosen or the nut 22 does not move. Therefore, the bolt 21 and the nut 22 may be fastened with a fastening torque lower than the specified fastening torque (the fastening torque when the bolt 21 and the nut 22 are finally tightened). For this, for example, the nut 22 is attached to the bolt 21 by hand tightening without using a tool.

In the joint portion 5 to which the reinforcing bar joining structure 1 is applied, the first reinforcing bar 11 and the second reinforcing bar 12 are joined by the diameter-expanding plates 15 that are abutted against each other and the connecting member 20 that connects the diameter-expanding plates 15 to each other. To. Further, the reinforcing bar main body 13, the diameter-expanding plate 15, and the connecting member 20 constituting the first reinforcing bar 11 and the second reinforcing bar 12 are embedded in the concrete 3c forming the concrete portion 3. As a result, the bolts 21 and nuts 22 constituting the connecting member 20 are fixed by the concrete 3c.
As described above, the reinforcing bar joint structure 1 includes the reinforcing bar main body 13 and the diameter-expanding plate 15 of the first reinforcing bar 11, the reinforcing bar main body 13 and the diameter-expanding plate 15 of the second reinforcing bar 12, and the bolt 21 and the nut 22. I have.

In such a reinforcing bar joining structure 1, in order to join the first reinforcing bar 11 and the second reinforcing bar 12, first, the enlarged diameter plate 15 of the first reinforcing bar 11 and the enlarged diameter plate 15 of the second reinforcing bar 12 are joined. Hit each other. At this time, the through hole 16 of the enlarged diameter plate 15 of the first reinforcing bar 11 and the through hole 16 of the enlarged diameter plate 15 of the second reinforcing bar 12 communicate with each other.

Next, for example, the screw shaft 21a of the bolt 21 is inserted into the through hole 16 from the diameter-expanding plate 15 side of the first reinforcing bar 11 toward the diameter-expanding plate 15 side of the second reinforcing bar 12.

After that, the nut 22 is attached to the tip of the screw shaft 21a of the bolt 21 protruding from the enlarged diameter plate 15 of the second reinforcing bar 12, and the nut 22 is screwed. At this time, the nut 22 may be tightened with a tool or only lightly tightened by hand.

By tightening the bolts 21 and nuts 22 in all the through holes 16, the diameter-expanding plate 15 of the first reinforcing bar 11 and the diameter-expanding plate 15 of the second reinforcing bar 12 are connected by the connecting member 20. As a result, one end 11a of the first reinforcing bar 11 and one end 12a of the second reinforcing bar 12 are joined.

In this way, after arranging a predetermined number of the first reinforcing bars 11 and the second reinforcing bars 12, a formwork (not shown) is assembled around the reinforcing bars 11, and concrete 3c is placed inside the formwork (not shown). After that, the concrete 3c is cured for a predetermined time to develop a predetermined strength, whereby the structural material 2 is formed.

In the joint portion 5 of the joint structure 1 of such reinforcing bars, since the enlarged diameter plates 15 abut against each other, the force in the compression direction in which the first reinforcing bar 11 and the second reinforcing bar 12 approach each other is transmitted. The connecting member 20 that connects the enlarged diameter plates 15 to each other transmits a force in the tensile direction that separates the first reinforcing bar 11 and the second reinforcing bar 12 from each other.

In the reinforcing bar joining structure configured in this way, the first reinforcing bar 11 and the second reinforcing bar 12 can be joined by connecting the enlarged diameter plates 15 abutting each other with the connecting member 20. When joining the first reinforcing bar 11 and the second reinforcing bar 12, the connecting member 20 is inserted into the through hole 16 formed in the diameter-expanding plate 15 with the diameter-expanding plates 15 abutting against each other to expand the diameter. The plates 15 may be connected to each other. As a result, even if other reinforcing bars or the like are present around the first reinforcing bar 11 and the second reinforcing bar 12, the joining work is not hindered. In addition, it is possible to suppress the influence of the weather during construction and to suppress the lengthening of the construction period. Further, since the enlarged diameter plates 15 abut against each other, the force in the compression direction in which the first reinforcing bar 11 and the second reinforcing bar 12 approach each other can be reliably transmitted. Further, the connecting member 20 that connects the enlarged diameter plates 15 to each other can reliably transmit the force in the tensile direction in which the first reinforcing bar 11 and the second reinforcing bar 12 are separated from each other. Further, the diameter-expanding plate 15 extending radially outward in the first reinforcing bar 11 and the second reinforcing bar 12 may have a size (diameter dimension) for providing the connecting member 20 to be inserted into the through hole 16. , It is possible to prevent it from becoming excessively large in the radial direction.
Therefore, it is possible to easily join the reinforcing bars to each other and prevent the diameter of the joint portion from becoming large.

Further, the connecting member 20 includes a bolt 21 in which a screw shaft 21a is inserted from a through hole 16 of one diameter-expanding plate 15 into a through hole 16 of the other diameter-expanding plate 15, and a through hole 16 of the other diameter-expanding plate 15. A nut 22 mounted on the screw shaft 21a of the bolt 21 protruding from the bolt 21 is provided. In this way, the diameter-expanding plates 15 can be connected to each other by the bolts 21 and the nuts 22, and the first reinforcing bars 11 and the second reinforcing bars 12 can be joined. Commercially available products can be used for the bolt 21 and the nut 22. As a result, the structure of the joint portion 5 is simple and low cost, and the joining work can be easily performed. Further, by using the bolt 21 and the nut 22, the inspection after construction can be easily and quickly performed.

Further, the bolts 21 and nuts 22 constituting the connecting member 20 are fixed by being embedded in the concrete 3c to be driven later. Therefore, it is not necessary to fasten the bolt 21 and the nut 22 with the specified fastening torque (the fastening torque when the bolt 21 and the nut 22 are fully tightened), and the screw shaft 21a of the bolt 21 inserted through the through hole 16 does not need to be fastened. The first reinforcing bar 11 and the second reinforcing bar 12 can be joined even if the nut 22 is tightened by hand. Therefore, the joining work between the first reinforcing bar 11 and the second reinforcing bar 12 can be easily performed.

The assembly procedure shown in the above-described embodiment, or the shapes and combinations of the constituent members are examples, and various changes can be made based on the design requirements and the like without departing from the gist of the present invention.

For example, in the above embodiment, the diameter-expanding plate 15 is made circular, for example, when viewed from the stretching direction of the reinforcing bar main body 13, but may have a polygonal shape such as a rectangle. The arrangement and number of through holes 16 (connecting members 20) can be changed as appropriate. Further, the strength classification of the bolt 21 and the nut 22 constituting the connecting member 20, and the nominal diameter of the screw may be appropriately selected. For example, when shortening the construction time is required, high-strength bolts can be used for the bolts 21 to reduce the number of bolts.

Further, in the above embodiment, the diameter-expanding plate 15 is integrally formed with the reinforcing bar main body 13 by heat-molding the end portion 13a of the reinforcing bar main body 13, but the present invention is not limited to this. For example, the enlarged diameter plate 15 and the end portion 13a of the reinforcing bar main body 13 may be joined by frictional pressure welding. Further, the enlarged diameter plate 15 and the end portion 13a of the reinforcing bar main body 13 may be joined by welding. Further, by using a screw reinforcing bar for the reinforcing bar main body 13 and screwing it into a female screw groove formed on the inner peripheral surface of the reinforcing bar insertion hole 15h, the diameter expansion plate 15 and the end portion 13a of the reinforcing bar main body 13 are joined by screw joining. You may.

Further, in the above embodiment, the bolt 21 and the nut 22 are used as the connecting member 20, but for example, the nut 22 may be welded to the diameter-expanding plate 15 in advance. Further, instead of the nut 22, a female screw groove may be formed on the inner peripheral surface of the through hole 16 of one of the enlarged diameter plates 15, and the bolt 21 may be screwed into the female screw groove of the through hole 16.

1 ... Reinforcing bar joint structure 3c ... Concrete 11 ... First reinforcing bar 11a ... One end 12 ... Second reinforcing bar 12a ... One end 13 ... Reinforcing bar body (first reinforcing bar body, second reinforcing bar body)
15 ... Diameter expansion plate 16 ... Through hole 20 ... Connecting member 21 ... Bolt 21a ... Screw shaft 21b ... Head 22 ... Nut S ... Gap

Claims (3)

The first reinforcing bar body that extends in one direction and
A second reinforcing bar main body arranged on an extension line of the first reinforcing bar main body and having one end arranged to face one end of the first reinforcing bar main body.
A diameter-expanding plate having a plurality of through holes extending outward in the radial direction at one end of each of the first reinforcing bar main body and the second reinforcing bar main body and arranged at intervals in the circumferential direction.
With the diameter-expanding plate of the first reinforcing bar body and the diameter-expanding plate of the second reinforcing bar body abutting against each other, they are inserted into the through holes of both of the diameter-expanding plates, and the diameter-expanding plates are put together. A reinforcing bar joint structure comprising a connecting member to be connected. The connecting member
A bolt in which a screw shaft is inserted from the through hole of one of the enlarged diameter plates to the through hole of the other enlarged diameter plate.
The reinforcing bar joining structure according to claim 1, further comprising a nut mounted on the screw shaft of the bolt protruding from the through hole of the enlarged diameter plate. At least one of the head of the bolt and the nut is arranged with a gap between the first reinforcing bar main body and the second reinforcing bar main body in the extension direction of the enlarged diameter plate.
The joint structure for reinforcing bars according to claim 2, wherein the first reinforcing bar main body, the second reinforcing bar main body, the enlarged diameter plate, and the connecting member are embedded in concrete.

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