JP2023181721A - Jointing method of precast members - Google Patents

Abstract

To provide a jointing method of precast members allowing easy jointing, and improved in jointing strength thereof.SOLUTION: A jointing method of jointing first reinforcements 1 projecting sideward from a side face of one precast member 10 to second reinforcements 2 projecting sideward from the side face of the other precast member 20 in a lap joint, comprises steps of: setting spiral members 3 by making the spiral members penetrate the first reinforcements 1 of the one precast member 10; positioning the first reinforcements 1 and the second reinforcements 2 to be the lap joint arrangement by, in a sate of the spiral members 3 retreated to a position closer to the side face of the one precast member 10, moving the other precast member 20 to the direction roughly orthogonal to the extending direction of the second reinforcements 2; setting the spiral members 3 by sliding to cover the lap joint part of the first reinforcements 1 and the second reinforcements 2; and forming a joint part 30 by placing a solidification material among the precast members.SELECTED DRAWING: Figure 5

Description

The present invention relates to a method for joining precast members.

Conventionally, a joining technique using a loop joint is known as a method for joining precast members (see, for example, Patent Document 1).
Furthermore, as a method for joining precast members, a technique is known in which a reinforcing bar protruding from the end of the other precast member is inserted into an insertion hole formed by a sheath pipe in one precast member to join the other precast member ( For example, see Patent Document 2).

JP 2021-98939 Publication Japanese Patent Application Publication No. 2019-167689

However, in the case of the technique disclosed in Patent Document 1, there is a problem in that processing of reinforcing bars to form a loop joint requires time and effort. Furthermore, considering that the deformation performance of the loop joint during an earthquake is low, it is necessary to increase the cross-sectional area of the member, and the accompanying cost increase has sometimes been a problem.
Furthermore, in the case of the technique disclosed in Patent Document 2, precision is required to insert the reinforcing bars of one precast member into the insertion holes of the other precast member, so the joining work is relatively difficult. In particular, when inserting the reinforcing bars of precast members that will become columns or beams into the insertion holes of precast members that will become columns or beams, it is necessary to move the precast members in an approximately horizontal direction, so heavy precast members cannot be used. There were problems in that it was difficult to move the structure horizontally using a crane, etc., and the construction period was relatively long because it had to be carried out by pushing one side from the standard pillar.

An object of the present invention is to provide a method for joining precast members that can be easily joined and improve the joining strength.

In order to achieve the above object, this invention
A method for joining precast members in which a first reinforcing bar protruding laterally from the side surface of one precast member and a second reinforcing bar protruding laterally from the side surface of the other precast member are joined by forming a lap joint. There it is,
inserting and installing a spiral member having an inner diameter through which at least two reinforcing bars can be inserted through the first reinforcing bar of the one precast member;
With the spiral member retracted to a position near the side of the one precast member, the other precast member is moved so that the first reinforcing bar and the second reinforcing bar are arranged in a lap joint. a step of aligning the
sliding and installing the helical member so as to cover the lap joint between the first reinforcing bar and the second reinforcing bar;
placing a solidified material between the one precast member and the other precast member, and curing the solidified material to form a joint;
It was made to have the following.

In a method for joining precast members having such a configuration, for example, one precast member is dropped into the other precast member in a substantially vertical direction, and the first reinforcing bar of one precast member and the second reinforcing bar of the other precast member are connected. After aligning the reinforcing bars in the lap joint arrangement, the helical member can be used to cover the lap joint and reinforce the joint, so that the reinforcing bars at the joint between one precast member and the other precast member are The generated tensile stress can be transmitted and the strength of the joint can be improved.
Specifically, the spiral member that covers the lap joint of reinforcing bars restrains the solidified material at the joint, so a large tensile stress acts on each reinforcing bar, causing the solidified material to expand and cause cracks. It can resist the force that is trying to be generated, and the anchoring strength of the lap joint can be greatly improved.
In particular, if the joining method involves moving one precast member approximately vertically to the other to form a lap joint between the first reinforcing bar and the second reinforcing bar, heavy precast members can be moved using a crane or the like. Since there is no need to move horizontally and insert reinforcing bars, precast members can be easily joined.
In other words, with this precast member joining method, the precast members can be easily joined and the joining strength can be improved.

Also, preferably,
In the state where the spiral member is retracted to a position near the side of the one precast member, the spiral member is contracted in its expansion and contraction direction,
After the first reinforcing bar and the second reinforcing bar are arranged in a lap joint, the helical member is restored to elongate.

For example, when moving one precast member approximately vertically so as to drop the other precast member, if the spiral member retracted to a position near the side of one precast member is contracted, the first Since this does not interfere with arranging the first and second reinforcing bars adjacent to each other (lap joint arrangement), the overlap joint portion between the first and second reinforcing bars can be made longer. Then, it becomes possible to cover the overlapped joint portion with the spiral member restored so as to be expanded.
In addition, if the spiral member retracted to the side of one of the precast members is contracted, it will be possible to arrange the first and second reinforcing bars adjacent to each other (lap joint arrangement). Not a hindrance. In that case, the distance between precast members can be shortened and the joints can be made smaller, so the amount of solidified material (concrete, etc.) placed on site can be reduced, and the amount of joint work can be reduced. becomes possible.

Also, preferably,
including the step of installing a spiral reinforcement that restrains the solidified material at a position along the spiral member installed so as to cover the lap joint portion of the first reinforcement and the second reinforcement. do.

When the spiral reinforcement is installed along the helical member covering the lap joint between the first and second reinforcing bars, the spiral reinforcement appropriately restrains the solidified material, so that the precast member The deformation performance of joints during earthquakes can be significantly improved.

Also, preferably,
With the spiral member retracted to a position near the side of the one precast member, the spiral reinforcement that restrains the solidified material is expandable and contractible in the extending direction of the first reinforcing bar and the second reinforcing bar. Including the process of installing in a posture,
The spiral muscle is contracted in the direction of expansion and contraction in a state where it is retracted to a position near the side of the one precast member,
After the first reinforcing bar and the second reinforcing bar are arranged in a lap joint, the spiral reinforcing bar is restored so as to be elongated.

For example, when moving one precast member in a substantially vertical direction so as to drop the other precast member, if the spiral muscle retracted to a position near the side of one precast member is contracted, the first This does not interfere with the arrangement of the second reinforcing bar and the second reinforcing bar adjacent to each other (lap joint arrangement).
Even when the spiral reinforcement is installed in this manner, the spiral reinforcement appropriately restrains the solidified material, so that the deformation performance of the joint portion of the precast member during an earthquake can be significantly improved.

Also, preferably,
The spiral member is made up of a plurality of divided spiral bodies.

Even a helical member consisting of multiple divided helices can restrain solidified material, and large tensile stress acts on each reinforcing bar, causing the solidified material to expand and cause cracks. It is possible to improve the fixing strength of the lap joint.

According to the present invention, precast members can be easily joined and the joining strength thereof can be improved.

FIG. 3 is an explanatory diagram regarding the procedure of a method for joining precast members according to the present embodiment. FIG. 3 is an explanatory diagram regarding the procedure of a method for joining precast members according to the present embodiment. FIG. 3 is an explanatory diagram regarding the procedure of a method for joining precast members according to the present embodiment. FIG. 3 is an explanatory diagram regarding the procedure of a method for joining precast members according to the present embodiment. FIG. 3 is an explanatory diagram regarding the procedure of a method for joining precast members according to the present embodiment. FIG. 3 is an explanatory diagram regarding the procedure of a method for joining precast members according to the present embodiment. FIG. 7 is a schematic explanatory diagram showing a cross-sectional view of the reinforcement of the joint portion shown in FIG. 6; FIG. 3 is an explanatory diagram regarding the procedure of a method for joining precast members according to the present embodiment. FIG. 7 is a schematic explanatory diagram showing a modified example of reinforcement at a joint portion. FIG. 7 is a schematic explanatory diagram showing a modified example of reinforcement at a joint portion. FIG. 7 is a schematic explanatory diagram showing a modified example of reinforcement at a joint portion.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a method for joining precast members according to the present invention will be described in detail with reference to the drawings. However, although various limitations that are technically preferable for carrying out the present invention are attached to the embodiments described below, the scope of the present invention is not limited to the following embodiments and illustrated examples.

The method of joining precast members according to the present embodiment includes a plurality of first reinforcing bars 1 protruding laterally from the side surface of one precast member 10 and a plurality of first reinforcing bars 1 protruding laterally from the side surface of the other precast member 20. This is a technique for joining one precast member 10 and the other precast member 20 by making a lap joint with the second reinforcing bar 2. It is possible to join one precast member 10 with the other precast member 20 with a simple work, and it is possible to join firmly and to improve deformation performance during an earthquake. This is a bonding technology that has made it possible to improve the performance.
In this embodiment, the construction procedure will be explained using an example in which beam members are joined together as precast members.
Note that the first reinforcing bars 1 protrude laterally approximately perpendicularly from the side surface of one precast member 10, and the second reinforcing bars 2 protrude laterally approximately perpendicularly from the side surface of the other precast member 20. There is.
Furthermore, when one precast member 10 and the other precast member 20 face each other with the first reinforcing bars 1 and second reinforcing bars 2 facing each other, the first reinforcing bars 1 and the second reinforcing bars 2 are arranged in a lap joint. A first reinforcing bar 1 is disposed on one precast member 10, and a second reinforcing bar 2 is disposed on the other precast member 20 so that the precast member 10 has a first reinforcing bar 1 arranged therein.

First, as shown in FIG. 1, the spiral member 3 is inserted and installed through the first reinforcing bar 1 of one of the precast members 10 that is installed on a column 51 that is a predetermined location.
The spiral member 3 is, for example, a spiral member formed by concentrically winding a linear steel material (steel bar, wire rod, etc.), and includes at least two reinforcing bars (here, a first reinforcing bar 1 and a second reinforcing bar 1). It has an inner diameter through which the reinforcing bar 2) can be inserted.

Next, as shown in FIGS. 2 and 3, while the spiral member 3 inserted through the first reinforcing bar 1 is retracted to a position near the side of one precast member 10, the other precast member 20 is moved. It is moved in a direction substantially perpendicular to the extending direction of the second reinforcing bar 2 and installed on the column 52 at a predetermined location.
Here, the other precast member 20 suspended by a crane or the like is moved approximately vertically so as to be dropped from above and installed on the column 52, and at that time, the first reinforcing bar 1 and the second reinforcing bar 2 are and are aligned so that they form a lap joint arrangement.
Note that the technology for joining and installing the precast member on the column and its joining structure are the same as those conventionally known, so they will not be described in detail here.
Moreover, the arrangement of the lap joint of the first reinforcing bars 1 and the second reinforcing bars 2 as used herein refers to an arrangement in which the first reinforcing bars 1 and the second reinforcing bars 2 are arranged adjacent to each other in substantially parallel. Here, in the figure, the first reinforcing bars 1 and the second reinforcing bars 2 are arranged to be substantially parallel and adjacent to each other and lined up left and right.
Further, the spiral member 3, which is retracted to a position closer to the side surface of one of the precast members 10, is contracted in its expansion and contraction direction.

Next, as shown in FIG. 4, the spiral member 3 is slid and installed so as to cover the overlapping joint portion of the first reinforcing bar 1 and the second reinforcing bar 2.
At this time, the contracted spiral member 3 has been restored, and the restored spiral member 3 covers the lap joint portion.
By covering the lap joint portion between the first reinforcing bar 1 and the second reinforcing bar 2 with the spiral member 3, the portion where reinforcing bars and steel materials overlap increases.
The spiral member 3 covering the lap joint between the first reinforcing bar 1 and the second reinforcing bar 2 restrains the solidified material (concrete, mortar, etc.), which will be described later, so that each reinforcing bar 1, A large tensile stress acts on 2, causing the solidified material (joint section 30 to be described later) to expand and resist the force that tends to cause cracks, thereby greatly improving the anchoring strength of the lap joint. .
Note that it is sufficient if the helical member 3, which had been contracted, is restored so as to be expanded after the first reinforcing bar 1 and the second reinforcing bar 2 are arranged in a lap joint (the arrangement shown in FIG. 3). , it is not limited to restoring at the timing of sliding movement.

As described above, if the spiral member 3 retracted to a position near the side of one of the precast members 10 is contracted, the first reinforcing bar 1 and the second reinforcing bar 2 can be placed adjacent to each other on the left and right ( Since it does not interfere with the arrangement of the overlap joint (the arrangement of the overlap joint), the overlap joint portion between the first reinforcing bar 1 and the second reinforcing bar 2 can be made longer, and the helical member 3 restored so as to be elongated can be made longer. This makes it possible to cover the lap joint portion for a long time.
Furthermore, the length of the joint portion 30 (described later), which is the sum of the lap joint length and the range in which the spiral member 3 is retracted, can be reduced.
In addition, if the lap joint part can be short due to the design, there is no need to shrink the spiral member 3, and the other precast member 20 is dropped into the first reinforcing bar 1. After aligning the second reinforcing bars 2 with the overlap joint, the spiral member 3 may be slid to cover the overlap joint.

Next, as shown in FIG. 5, one precast member 10 and the other precast member 10 are placed along the spiral member 3 installed so as to cover the lap joint between the first reinforcing bar 1 and the second reinforcing bar 2. A spiral reinforcement 4 is installed to restrain the concrete placed between the precast member 20 and the precast member 20.
Specifically, the spiral reinforcing bars 4 are installed in a posture that allows them to expand and contract in the extending direction of the first reinforcing bars 1 and the second reinforcing bars 2. In other words, the spiral muscle 4 is installed in a posture that allows it to expand and contract in the direction in which one precast member 10 and the other precast member 20 face each other.
Here, since there are no reinforcing bars 1 and 2 that would interfere with the installation of the spiral reinforcing bars 4, after arranging the reinforcing bars 1 and 2 in a lap joint, for example, inserting the spiral reinforcing bars 4 from the side of the precast members 10, 20. It is set up to do so.
In addition, while the spiral member 3 is retracted to a position closer to the side surface of one precast member 10, the spiral muscle 4 is retracted to a position closer to the side surface of one precast member 10, and contracted in the direction of expansion and contraction. After the first reinforcing bars 1 and the second reinforcing bars 2 are placed in a lap joint arrangement, the spiral reinforcing bars 4 may be stretched and restored.
The spiral reinforcement 4 is, for example, a spiral reinforcement formed by concentrically winding a linear steel material (steel bar, wire rod, etc.).
By installing such a spiral bar 4 along the spiral member 3 that covers the lap joint between the first reinforcing bar 1 and the second reinforcing bar 2, there are many areas where the reinforcing bars and steel materials overlap. Since the spiral reinforcement 4 suitably restrains the solidified material (concrete, mortar, etc.) described later, the deformation performance of the joint portion of the precast members during an earthquake can be greatly improved.

Next, as shown in FIGS. 6 and 7, stirrups 5 are arranged to surround the first reinforcing bars 1 and second reinforcing bars 2 near the outer edges of the precast members (10, 20). do.
By providing the stirrup 5 that surrounds the plurality of first reinforcing bars 1 and second reinforcing bars 2 on the outer circumferential side, the shear strength of the joint and the deformation performance during an earthquake can be improved.

Next, as shown in FIG. 8, a solidified material such as concrete or mortar is cast between one precast member 10 and the other precast member 20 using a formwork (not shown), and the solidified material is hardened. By forming the joint portion 30, the work of joining one precast member 10 and the other precast member 20 is completed.
Note that the solidified material may be a resin-based material.

In this way, in the precast member joining method of this embodiment, the other precast member 20 is dropped into one precast member 10 in the substantially vertical direction, and the first reinforcing bar 1 of one precast member 10 is connected to the other precast member 10. After aligning the second reinforcing bars 2 of the other precast member 20 to the position of the lap joint, the helical member 3 covers the lap joint to improve the fixing performance of the joint. It is possible to improve the joint strength of the structure and its deformation performance during earthquakes.
In addition, since the helical member 3 covers the lap joint and restrains the solidified material at the joint 30, large tensile stress acts on each reinforcing bar 1 and 2, causing the solidified material to expand and crack. It is possible to resist the force that tends to occur, and the anchoring strength of lap joints can be greatly improved.
Furthermore, the cross-sectional area of the precast members 10 and 20 can be made smaller than in the case of using conventional loop joints, making it possible to achieve miniaturization and reducing the beam height (beam size).
Further, by disposing the spiral reinforcement 4 in the joint 30, the deformation performance of the joint 30 during an earthquake can be further improved, and the precast members 10, 20 can be further miniaturized.

In particular, with this method of joining precast members, there is no need to move the precast members in a substantially horizontal direction and insert reinforcing bars, so the precast members can be easily joined together.
Also, in the production of precast members, reinforcing bars from one precast member may be inserted into the sheath hole of the other precast member, or reinforcing bars from the other precast member may be inserted into the sleeve hole of a mechanical joint of one precast member. As a result, it becomes unnecessary to directly fix the reinforcing bars to each other, and it becomes possible to manufacture the reinforcing bars with a margin of precision in arrangement, so that the precast member can be easily manufactured.
Furthermore, since it is no longer necessary to move precast members approximately horizontally and insert reinforcing bars, single-push construction is no longer required, and simultaneous construction is possible for each span where precast members such as beam members are joined. , it is possible to shorten the construction period.

As described above, with the precast member joining method of the present embodiment, the precast members can be easily joined, and the anchoring strength of the lap joint and the deformation performance of the joint during an earthquake can be improved.

Note that the present invention is not limited to the above embodiments.
For example, as shown in FIG. 9, spiral striations 4 may be installed in two vertically stacked layers at the joint portion (joint portion 30) of the precast members.
In addition, when precast members are joined near the center of the span of a beam member or column member, the bending moment during an earthquake that acts on the joint 30 is relatively small, and the seismic performance required for the joint 30 in design is small. Therefore, for example, as shown in FIG. 10, it is also possible to omit the arrangement of the spiral muscle 4.
In this way, depending on the cross-sectional area of the precast members (10, 20), by changing the design such as increasing or decreasing the number of spiral reinforcements 4 arranged at the joint part (joint part 30), the joint part can be improved. 30 seismic performance can be optimized.

In addition, in the above embodiment, a lap joint in which the first reinforcing bar 1 and the second reinforcing bar 2 are arranged horizontally and adjacent to each other in substantially parallel has been described as an example, but for example, as shown in FIG. The reinforcing bar 1 and the second reinforcing bar 2 may be a lap joint in which the reinforcing bars 1 and the second reinforcing bars 2 are arranged vertically adjacent to each other in substantially parallel.

Further, in the above embodiment, the case where one spiral member 3 is installed so as to cover the lap joint between the first reinforcing bar 1 and the second reinforcing bar 2 has been described as an example, but the present invention is limited to this. Instead, a spiral member 3 made up of a plurality of divided spiral bodies may be used.
Even if the spiral member 3 is made up of a plurality of divided spiral bodies, the solidified material at the joint 3 can be restrained, so a large tensile stress acts on each reinforcing bar 1, 2, causing the solidified material to expand. It is possible to resist the force that tends to cause cracks, and it is possible to improve the anchoring strength of the lap joint.
Note that the spiral body is a substantially ring-shaped member, and may be a member having a shape such as a so-called double ring or a double can.

Further, in the above embodiments, the case where beam members as precast members are joined together has been described as an example, but the present invention is not limited to this, and the case where beam members and column members as precast members are joined together is explained as an example. For joining, the method for joining precast members of this embodiment may be applied, in which the lap joint portions of mutual reinforcing bars are covered and reinforced with the spiral member 3.

In addition, it goes without saying that the specific detailed structure and the like can also be changed as appropriate.

10 One precast member 20 Other precast member 30 Joint portion 1 First reinforcing bar 2 Second reinforcing bar 3 Spiral member 4 Spiral bar 5 Stirrup 51 Column body 52 Column body

Claims (5)

A method for joining precast members in which a first reinforcing bar protruding laterally from the side surface of one precast member and a second reinforcing bar protruding laterally from the side surface of the other precast member are joined by forming a lap joint. There it is,
inserting and installing a spiral member having an inner diameter through which at least two reinforcing bars can be inserted through the first reinforcing bar of the one precast member;
With the spiral member retracted to a position near the side of the one precast member, the other precast member is moved so that the first reinforcing bar and the second reinforcing bar are arranged in a lap joint. a step of aligning the
sliding and installing the helical member so as to cover the lap joint between the first reinforcing bar and the second reinforcing bar;
placing a solidified material between the one precast member and the other precast member, and curing the solidified material to form a joint;
A method for joining precast members, comprising: In the state where the spiral member is retracted to a position near the side of the one precast member, the spiral member is contracted in its expansion and contraction direction,
The method for joining precast members according to claim 1, wherein after the first reinforcing bars and the second reinforcing bars are arranged in a lap joint, the spiral member is restored so as to be elongated. . including the step of installing a spiral reinforcement for restraining the solidified material at a position along the spiral member installed to cover the lap joint portion of the first reinforcement and the second reinforcement. The method for joining precast members according to claim 1 or 2. With the spiral member retracted to a position near the side of the one precast member, the spiral reinforcement that restrains the solidified material is expandable and contractible in the extending direction of the first reinforcing bar and the second reinforcing bar. Including the process of installing in a posture,
The spiral muscle is contracted in the direction of expansion and contraction in a state where it is retracted to a position near the side of the one precast member,
The joining of precast members according to claim 1 or 2, wherein after the first reinforcing bars and the second reinforcing bars are arranged in a lap joint, the spiral reinforcing bars are restored so as to be elongated. Method. 3. The method for joining precast members according to claim 1, wherein the spiral member is composed of a plurality of divided spiral bodies.

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