JP7456808B2 - Column-to-beam joint structure and construction method for column-to-beam joint structure - Google Patents

Description

The present invention relates to a column-to-beam joint structure and a method for constructing a column-to-beam joint structure.

BACKGROUND ART Conventionally, a joint structure is known in which a concrete-filled steel pipe column, in which the inside of a steel pipe is filled with joint reinforcing bars (main reinforcement) and concrete, and steel-framed beams placed above and below the concrete-filled steel pipe column. If there is an area (unreinforced area) in the vertical center of a concrete-filled steel pipe column where joint reinforcing bars are not placed, the steel pipe will become hot in the event of a fire, and the restraining effect of the steel pipe will almost disappear, causing shear failure of the unreinforced area. There was a problem that it ended up happening.

Patent Document 1 below proposes a concrete-filled steel pipe column in which a reinforcing reinforcing bar body is disposed inside the column. The reinforcing bar body includes a plurality of vertical reinforcing bars extending in the vertical direction and arranged at intervals along the circumferential direction, and a plurality of reinforcing bars arranged at intervals in the vertical direction so as to bundle the plurality of vertical reinforcing bars. It has a shear reinforcing bar (circular reinforcing bar) that is circular in plan view. The shear reinforcement of the reinforcing steel body can ensure the shear transmission performance and axial force transmission performance of the column.

Japanese Patent Application Publication No. 2018-131770

However, in the column-to-beam joint structure described in Patent Document 1, it is necessary to arrange the joint reinforcing bars and reinforcing bars inside the column in separate work processes, so there is a problem that construction time is required. be. In addition, since it is necessary to fabricate the shear reinforcing bars by bending straight reinforcing bars into a circular shape in advance, there is a problem that processing time and processing time are required. Furthermore, if the required fixing length of the joint reinforcing bars is long, there is a problem in that the joint reinforcing bars on the lower floor and the joining reinforcing bars on the upper floor interfere with each other, making reinforcement difficult to arrange.

Therefore, the present invention has been made in view of the above circumstances, and provides a column-to-beam joint structure and a column-to-beam joint structure that are easy to construct while ensuring the shear transmission performance and axial force transmission performance of columns in the event of a fire. Provides a construction method for a joint structure with.

In order to achieve the above object, the present invention employs the following means.
That is, the column-beam joint structure according to the present invention is a joint structure between a column of concrete-filled steel pipe construction and a beam of steel frame construction, the column having a steel pipe extending in the vertical direction, a plurality of upper joint reinforcing bars arranged inside the steel pipe along the circumferential direction and extending downward from above the steel pipe, and a plurality of lower joint reinforcing bars arranged inside the steel pipe along the circumferential direction and extending upward from the bottom of the steel pipe, a plug member arranged in communication with the steel pipe, a joint beam joined to the beam, and a concrete portion filled inside the steel pipe and inside the plug member, the joint beam and the plug member are integrally molded, the upper joint reinforcing bar has an upper vertical portion extending in the vertical direction, and a lower portion of the upper vertical portion has a concrete portion filled with concrete. and an upper inclined portion arranged so as to incline relative to the upper vertical portion, the lower connecting steel bar extending in the vertical direction having a lower vertical portion arranged directly below the upper vertical portion and a lower inclined portion arranged at the top of the lower vertical portion so as to incline relative to the lower vertical portion, the lower end of the upper inclined portion being arranged lower than the upper end of the lower inclined portion, and when viewed from the vertical direction, the upper vertical portions and the lower vertical portions are arranged in a dispersed manner in a plurality of vertical portion arrangement areas, the lower end of the upper inclined portion being arranged in a first concentration area between adjacent vertical portion arrangement areas, and the upper end of the lower inclined portion being arranged in a second concentration area different from the first concentration area between adjacent vertical portion arrangement areas.

In the column-to-beam joint structure configured in this way, the lower ends of the plurality of upper slopes are arranged in the first gathering area, and the upper ends of the plurality of lower slopes are arranged in the second gathering area. This provides shear reinforcement. Therefore, even if the steel pipe reaches a high temperature during a fire, the filling concrete restraint effect can be maintained, and the shear transmission performance and axial force transmission performance of the column can be ensured.
Further, there is no need to arrange reinforcing bars such as reinforcing bars inside the steel pipe separately from the upper joint reinforcing bars and the lower joining reinforcing bars as in the conventional method, and the construction is easy.

Further, in the column-to-beam joint structure according to the present invention, when viewed from the vertical direction, the plurality of upper inclined portions are arranged so as to intersect in the first gathering region, and the plurality of upper inclined portions are arranged so as to intersect in the second gathering region. The lower inclined portions may be arranged to intersect.

In the joint structure between columns and beams configured in this way, a plurality of upper slopes are arranged so as to intersect in the first gathering area, and a plurality of lower slopes are arranged so as to intersect in the second gathering area. has been done. As a result, an X-shaped reinforcement arrangement is formed by the plurality of upper sloped portions, and an X-shaped reinforcement arrangement is formed by the plurality of lower sloped portions. Therefore, the shear strength can be further increased by the X-shaped reinforcing arrangement (the plurality of upper sloped parts and the plurality of lower sloped parts) arranged perpendicularly to the shear cracks that may occur.

Further, in the column-to-beam joint structure according to the present invention, the height of the lower end of the upper inclined part reaches the height of the upper end of the lower vertical part, and the height of the upper end of the lower inclined part is The height may reach the height of the lower end of the upper vertical portion.

In the joint structure between columns and beams configured in this way, the lower end of the upper slope reaches the height of the upper end of the lower vertical part, and the upper end of the lower slope reaches the height of the lower end of the upper vertical part. It has reached the top. Therefore, the required fixing length of the upper slope portion and the lower slope portion becomes longer, so that the shear strength can be further increased.

Further, a method for constructing a joint structure between a column and a beam according to the present invention is a method for constructing a joint structure between a column and a beam according to any one of the above, in which the structure extends upwardly from the floor surface. a steel pipe installation step of installing the steel pipe so as to surround the plurality of lower joint reinforcing bars; a joining member having the closing member and the joining beam integrally molded with the closing member and joined to the beam ; and the upper side a joined body installation step of installing a joined body in which the joining reinforcing bars and the lower joining reinforcing bars are integrated so that the blocking member communicates with the steel pipe; a beam joining step of joining the beam to the joining beam; The method is characterized by comprising a concrete placing step of placing concrete inside the steel pipe and inside the closing member.

In the construction method of the column-to-beam joint structure configured in this way, a plurality of upper slope parts are arranged in the first concentration area and a plurality of lower slope parts are arranged in the second concentration area. , shear reinforced. Therefore, even if the steel pipe reaches a high temperature during a fire, the filling concrete restraint effect can be maintained, and the shear transmission performance and axial force transmission performance of the column can be ensured.
Further, there is no need to arrange reinforcing bars such as reinforcing bars inside the steel pipe separately from the upper joint reinforcing bars and the lower joining reinforcing bars as in the conventional method, and the construction is easy.
In addition, by integrating the joining members, upper joining reinforcing bars, and lower joining reinforcing bars, the joining members, upper joining reinforcing bars, and lower joining reinforcing bars can be installed at the same time, reducing the number of times cranes are used during erection. be able to.

Further, a method for constructing a joint structure between a column and a beam according to the present invention is a method for constructing a joint structure between a column and a beam according to any one of the above, in which the structure extends upwardly from the floor surface. a steel pipe installation step of installing the steel pipe so as to surround the plurality of lower joint reinforcing bars, and a joining member having the closing member and the joining beam integrally molded with the closing member and joined to the beam. a joining member installation step of installing a member so as to communicate with the steel pipe; and installing a joining reinforcing bar having the upper joining reinforcing bar and the lower joining reinforcing bar so that the lower joining reinforcing bar is arranged inside the steel pipe. a beam joining step of joining the beam to the joining beam; and a concrete pouring step of pouring concrete inside the steel pipe and inside the closing member. .

In the construction method of the column-to-beam joint structure configured in this way, a plurality of upper slope parts are arranged in the first concentration area and a plurality of lower slope parts are arranged in the second concentration area. , shear reinforced. Therefore, even if the steel pipe reaches a high temperature during a fire, the filling concrete restraint effect can be maintained, and the shear transmission performance and axial force transmission performance of the column can be ensured.
Further, there is no need to arrange reinforcing bars such as reinforcing bars inside the steel pipe separately from the upper joint reinforcing bars and the lower joining reinforcing bars as in the conventional method, and the construction is easy.

The column-beam joint structure and the construction method for the column-beam joint structure of the present invention ensure the shear transmission performance and axial force transmission performance of the column in the event of a fire, while providing good construction ease.

FIG. 1 is a vertical cross-sectional view showing a joint structure between a column and a beam according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1. FIG. (a) A sectional view taken along the line BB in FIG. 1, and (b) a sectional view taken along the line CC in FIG. FIG. 2 is a diagram showing the internal configuration of a column in a column-beam joint structure according to an embodiment of the present invention. It is a figure which shows the construction method of the joint structure of the column and beam based on one Embodiment of this invention, (a) It is a figure which shows the steel pipe installation process, (b) It is a figure which shows the joint body installation process, ( c) It is a figure showing a beam joining process. 1A and 1B are diagrams illustrating a construction method of a joint structure between a column and a beam according to an embodiment of the present invention; FIG. 1A is a diagram illustrating a concrete filling process; FIG. FIG. 7 is a vertical cross-sectional view showing a joint structure between a column and a beam according to a modification of an embodiment of the present invention. 8 is a sectional view taken along the line DD in FIG. 7. FIG. FIG. 3 is a diagram showing a construction method of a joint structure between a column and a beam according to a modification of an embodiment of the present invention, (a) a diagram showing a steel pipe installation process, and (b) a diagram showing a joint member installation process. (c) is a diagram showing a joining reinforcing bar installation process and a beam joining process. 1A and 1B are diagrams showing a construction method for a joint structure between a column and a beam in accordance with a modified embodiment of the present invention, in which (a) is a diagram showing a concrete filling process, and (b) is a diagram showing a steel pipe installation process.

A joint structure between a column and a beam according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a vertical sectional view showing a joint structure between a column and a beam according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line AA in FIG.

As shown in FIG. 1, in the column-to-beam joint structure 100 of this embodiment, a steel beam 1 is joined to the upper and lower parts of a concrete-filled steel pipe column 4. As shown in FIG. 2, the beam 1 is arranged perpendicularly to the column 4 in plan view.

A pair of beams 1 are arranged so as to be perpendicular to each other in plan view. In this embodiment, each beam 1 is made of H-beam steel.

As shown in FIG. 1, the beam 1 has a pair of flanges 11 spaced apart in the vertical direction, and a web 12 connecting the pair of flanges 11. A connecting member 3 is connected to the end face of each beam 1 by a bolt or the like (not shown).

The joining member 3 has four joining beams 1X and a closing plate (closing member) 2, and is integrally molded. The four connecting beams 1X are orthogonally arranged.

The joint beam 1X is formed to have the same cross-sectional shape as the beam 1. The joint beam 1X includes a pair of joint flanges 11X arranged apart from each other in the vertical direction, and a joint web 12X that connects the pair of joint flanges 11X.

The orthogonally arranged joining flanges 11X are joined together. The orthogonally arranged joining webs 12X are joined together.

As shown in FIG. 2, a closing plate portion 2a formed in an arc shape is joined to the joining web 12X. The cover plate portion 2a connects the orthogonally arranged joining webs 12X. The height of the cover plate portion 2a is approximately the same as the height of the joining web 12X. The four cover plate parts 2a constitute a cover plate 2 formed in a substantially cylindrical shape with the vertical direction as the axial direction.

As shown in FIG. 1, the blocking plate 2 is formed coaxially with and has approximately the same diameter as the steel pipe 41 of the column 4 described below. The blocking member 2 is arranged directly above and below the steel pipe 41 so as to communicate with the steel pipe 41.

The column 4 has a steel pipe 41, multiple connecting reinforcing bars 42, and a concrete section 49.

Steel pipes 41 are installed on both sides of the beam 1, both above and below. The steel pipe 41 is formed into a cylindrical shape with the vertical direction as the axial direction.

The lower end 41b of the steel pipe 41 is simply installed on the upper surface of the joint beam 1X (the upper surface of the joint flange 11X), and is not welded to the upper surface of the joint flange 11X. The upper end 41u of the steel pipe 41 is placed in contact with the lower surface of the joint beam 1X (the lower surface of the joint flange 11X), and is not welded to the lower surface of the joint flange 11X.

The plurality of joint reinforcing bars 42 are arranged inside the steel pipe 41. The joint reinforcing bars 42 are inserted into the cylindrical cover plate 2 and extend from the upper steel pipe 41 to the lower steel pipe 41. In other words, inside one steel pipe 41, there are a lower part of the upper joint reinforcing bar 42 (hereinafter sometimes referred to as "upper joining reinforcing bar 42A") and a lower joining reinforcing bar 42 (hereinafter, "lower joining reinforcing bar 42B"). ”) is located at the top. A vertical portion 43 of the lower joint reinforcing bar 42B is arranged directly below a vertical portion 43 of the upper joining reinforcing bar 42A, which will be described later. In this embodiment, twelve joint reinforcing bars 42 are arranged (see FIG. 2).

The connecting rebar 42 has a vertical portion 43, a first inclined portion (upper inclined portion) 44, and a second inclined portion (lower inclined portion) 45.

The vertical portion 43 extends in the vertical direction. The vertical portions 43 are arranged inside the steel pipe 41 at intervals in the circumferential direction.

3(a) is a sectional view taken along line BB in FIG. 1, and FIG. 3(b) is a sectional view taken along line CC in FIG.
As shown in FIG. 3A, the area where the vertical part 43 is arranged is defined as area (vertical part arrangement area) R1. The regions R1 are formed at four locations at intervals along the inner circumferential surface of the steel pipe 41 (hereinafter sometimes referred to as "regions R11 to R14"). In this embodiment, three vertical portions 43 are arranged in each region R1.

FIG. 4 is a diagram showing the internal configuration of the pillar 4. As shown in FIG.
As shown in FIG. 4, the first inclined portion 44 is provided at the lower end portion 43b of the vertical portion 43. As shown in FIG. The first inclined portion 44 is provided so as to be inclined with respect to the vertical portion 43.

As shown in FIG. 3(b), the lower end portion 44b of the first inclined portion 44 is arranged in a region (first aggregation region) R2 between adjacent regions R1. Region R2 is formed in two locations (hereinafter sometimes referred to as "regions R21 and R22"). Region R21 is arranged between region R11 and region R14. Region R22 is arranged between region R12 and region R13.

The lower end portions 44b of the first inclined portions 44 of the upper joint reinforcing bars 42A arranged in the region R11 and the region R14 are concentrated in the region R21. The lower end portions 44b of the first inclined portions 44 of the upper joining reinforcing bars 42A arranged in the region R12 and the region R13 are concentrated in the region R22.

In the first inclined portion 44 of the upper joint reinforcing bar 42A arranged in the region R11, the first inclined portion 44 is inclined so that the lower end portion 44b faces the region R14 side. In the first inclined portion 44 of the upper joint reinforcing bar 42A arranged in the region R14, the first inclined portion 44 is inclined so that the lower end portion 44b faces the region R11 side. When viewed from the vertical direction, the first inclined part 44 of the upper joint reinforcing bar 42A arranged in the region R11 and the first inclined part 44 of the upper joining reinforcing bar 42A arranged in the region R14 are arranged so as to intersect with each other. There is.

In the first inclined portion 44 of the upper joining reinforcing bar 42A arranged in the region R12, the first inclined portion 44 is inclined so that the lower end portion 44b faces the region R13 side. In the first inclined portion 44 of the upper joint reinforcing bar 42A arranged in the region R13, the first inclined portion 44 is inclined so that the lower end portion 44b faces the region R12 side. When viewed from the vertical direction, the first inclined part 44 of the upper joint reinforcing bar 42A arranged in the region R12 and the first inclined part 44 of the upper joining reinforcing bar 42A arranged in the region R13 are arranged so as to intersect with each other. There is.

As shown in FIG. 4, the second inclined portion 45 is provided at the upper end portion 43u of the vertical portion 43. As shown in FIG. The second inclined portion 45 is provided so as to be inclined with respect to the vertical portion 43.

As shown in FIG. 3(a), the upper end 45u of the second inclined portion 45 is disposed in a region (second concentration region) R3 between adjacent regions R1. Region R3 is formed in two locations (hereinafter, sometimes referred to as "regions R31, R32"). Region R31 is disposed between regions R11 and R12. Region R32 is disposed between regions R13 and R14.

The upper end portion 45u of the second inclined portion 45 of the lower joint reinforcing bar 42B arranged in the region R11 and the region R12 is concentrated in the region R31. The upper end portions 45u of the second inclined portions 45 of the lower joining reinforcing bars 42B arranged in the region R13 and the region R14 are concentrated in the region R32.

In the second inclined portion 45 of the lower joint reinforcing bar 42B arranged in the region R11, the second inclined portion 45 is inclined so that the upper end portion 45u faces the region R12 side. In the second inclined portion 45 of the lower joint reinforcing bar 42B arranged in the region R12, the second inclined portion 45 is inclined such that the upper end portion 45u faces the region R11 side. When viewed from the vertical direction, the second inclined part 45 of the lower joint reinforcing bar 42B arranged in the region R11 and the second inclined part 45 of the lower joining reinforcing bar 42B arranged in the region R12 are arranged so as to intersect with each other. has been done.

In the second inclined portion 45 of the lower joint reinforcing bar 42B arranged in the region R13, the second inclined portion 45 is inclined so that the upper end portion 45u faces the region R14 side. In the second inclined portion 45 of the lower joint reinforcing bar 42B arranged in the region R14, the second inclined portion 45 is inclined so that the upper end portion 45u faces the region R13 side. When viewed from the vertical direction, the second inclined part 45 of the lower joint reinforcing bar 42B arranged in the region R13 and the second inclined part 45 of the lower joining reinforcing bar 42B arranged in the region R14 are arranged so as to intersect with each other. has been done.

As shown in FIG. 1, inside one steel pipe 41, a vertical part 43 (hereinafter sometimes referred to as "upper vertical part 43A") of the upper joint reinforcing bar 42A is arranged on the upper side. Inside one steel pipe 41, a vertical portion 43 (hereinafter sometimes referred to as “lower vertical portion 43B”) of a lower joint reinforcing bar 42B is arranged on the lower side. Inside one steel pipe 41, a first inclined part 44 of the upper joint reinforcing bar 42A and a second inclined part 45 of the lower joining reinforcing bar 42B are arranged approximately at the center in the vertical direction.

The lower end portion 44b of the first inclined portion 44 of the upper joint reinforcing bar 42A is arranged below the upper end portion 45u of the second inclined portion 45 of the lower vertical portion 43B. The lower end portion 44b of the first inclined portion 44 of the upper joint reinforcing bar 42A reaches the height of the upper end portion 43u of the lower vertical portion 43B of the lower joining reinforcing bar 42B. The upper end portion 45u of the second inclined portion 45 of the lower joint reinforcing bar 42B reaches the height of the lower end portion 43b of the upper vertical portion 43A of the upper joining reinforcing bar 42A.

The concrete portion 49 is filled inside the steel pipe 41 and inside the cover plate 2. The joint reinforcing bars 42 are fixed to the concrete portion 49.

Next, a method of constructing a joint structure between columns and beams will be explained.
FIG. 5 is a diagram showing a construction method of a joint structure between columns and beams, (a) a diagram showing the steel pipe installation process on the lower floor A, and (b) a diagram showing the joint installation process on the lower floor A. and (c) is a diagram showing the beam joining process on the lower floor A. FIG. 6 is a diagram showing the construction method of a joint structure between columns and beams, (a) a diagram showing the concrete filling process on the lower floor A, and (b) a diagram showing the steel pipe installation process on the upper floor B. be.

As shown in FIG. 5(a), the explanation will start from a state in which the lower joint reinforcing bars 42B are installed so as to protrude from the floor F of the lower floor A. A method for installing the lower joint reinforcing bars 42B will be described later.

First, the steel pipe installation process is performed.
The steel pipe 41 is installed so as to cover the plurality of lower joint reinforcing bars 42B arranged in the circumferential direction.

Next, a joined body installation process is performed.
As shown in FIG. 5(b), a joined body 5 is assembled in which the joining member 3, to which the cylindrical closing plate 2 is joined to the joining beam 1X, and the joining reinforcing bars 42 are integrated. The joint reinforcing bars 42 are inserted into the inside of the closing plate 2, the upper part of the joining reinforcing bars 42 (lower joining reinforcing bars 42B) is arranged above the closing plate 2, and the lower part of the joining reinforcing bars 42 (upper joining reinforcing bars 42A) is placed above the closing plate 2. It is in a state where it is placed below 2. The joined body 5 is installed so that the closing plate 2 communicates with the steel pipe 41.

Next, a beam joining process is performed.
As shown in FIG. 5(c), the beam 1 is joined to the joining beam 1X of the joining member 3 with bolts or the like. Also, install floor deck plates.

Next, the concrete placement process is performed.
As shown in FIG. 6(a), concrete is placed inside the steel pipe 41 and inside the cover plate 2. As a result, on the upper floor B, the lower joint reinforcing bars 42B protrude from the floor F.

Next, the above-mentioned steel pipe installation process, assembly installation process, beam joining process, and concrete pouring process are performed on the upper floor B.

In the construction method of the column-to-beam joint structure 100 and the column-to-beam joint structure configured in this way, the lower end portions 44b of the plurality of first inclined portions 44 are arranged in the region R2, and the plurality of lower end portions 44b are arranged in the region R3. By arranging the upper end portion 45u of the second inclined portion 45, shear reinforcement is achieved. Therefore, even if the steel pipe 41 becomes high in temperature during a fire, the filling concrete restraint effect can be maintained, and the shear transmission performance and axial force transmission performance of the column 4 can be ensured.

Further, there is no need to arrange reinforcing bars such as reinforcing bars inside the steel pipe 41 separately from the upper joining reinforcing bars 42A and the lower joining reinforcing bars 42B as in the prior art, and the workability is good.

Further, in region R2, a plurality of first slope portions 44 are arranged to intersect, and in region R3, a plurality of second slope portions 45 are arranged to intersect. As a result, an X-shaped reinforcement arrangement is formed by the plurality of first inclined parts 44, and an X-shaped reinforcement arrangement is formed by the plurality of second inclined parts 45. Therefore, the shear strength can be further increased by the X-shaped reinforcing arrangement (the plurality of first inclined parts 44 and the plurality of second inclined parts 45) arranged perpendicularly to the shear cracks that may occur.

Further, the lower end 44b of the first inclined part 44 reaches the height of the upper end 45u of the lower vertical part 43B, and the upper end 45u of the second inclined part 45 reaches the height of the lower end 44b of the upper vertical part 43A. . Therefore, the required anchorage length of the first inclined part 44 and the second inclined part 45 becomes longer, so that the shear strength can be further increased.

Furthermore, by integrating the joining member 3 with the upper joining reinforcing bars 42A and the lower joining reinforcing bars 42B, the joining member 3, the upper joining reinforcing bars 42A, and the lower joining reinforcing bars 42B can be installed at once, making it possible for cranes to can reduce the number of times it is used.

In addition, in order to prevent interference between the first inclined part 44 of the upper joint reinforcing bar 42A and the second inclined part 45 of the lower joint reinforcing bar 42B, the lower end part 44b of the first inclined part 44 is concentrated in the region R2, and the second inclined part 44 of the upper joint reinforcing bar 42A is The upper end 45u of the portion 45 is concentrated in a region R3 different from the region R2. Thereby, after installing the lower joint reinforcing bars 42B, the upper joining reinforcing bars 42A can be installed. In addition, it is possible to ensure the required fixing length of the upper joint reinforcing bars 42A and the lower joining reinforcing bars 42B, and also to have the effect of fireproof reinforcement.

(Modified example)
Next, a joint structure between a column and a beam according to a modification of the embodiment of the present invention will be described mainly using FIGS. 7 to 10.
In the following modified examples, the same members as those used in the embodiment described above are given the same reference numerals, and the explanation thereof will be omitted.

FIG. 7 is a vertical sectional view showing a joint structure between a column and a beam according to a modification of the embodiment of the present invention. FIG. 8 is a sectional view taken along line DD in FIG.
As shown in FIGS. 7 and 8, in the column-beam joint structure 100D of this modification, the joint beams 1X are connected by an outer diaphragm 21. As shown in FIGS. The outer diaphragm 21 and the joint flange 11X of the joint beam 1X are integrated by welding or the like.

The outer diaphragms 21 are provided at the upper and lower ends of the cylindrical cover plate 2. The outer diaphragm 21 is formed in a generally rectangular shape in a plan view, and the joint flanges 11X of the joint beam 1X are connected to its four corners. The outer diaphragm 21 and the cover plate 2 are integrated by welding or the like.

The lower end 41b of the steel pipe 41 is simply installed on the upper surface of the outer diaphragm 21, and is not welded to the upper surface of the outer diaphragm 21.

Next, a construction method for the joint structure between the pillars and the beams will be described.
Fig. 9 is a diagram showing a construction method for such a joint structure between a column and a beam, (a) a diagram showing a steel pipe installation process on the lower floor A, (b) a diagram showing a joint member installation process on the lower floor A, and (c) a diagram showing a joint rebar installation process and a beam joining process on the lower floor A. Fig. 10 is a diagram showing a construction method for such a joint structure between a column and a beam, (a) a diagram showing a concrete filling process on the lower floor A, and (b) a diagram showing a steel pipe installation process on the upper floor B.

As shown in FIG. 9(a), the explanation will start from a state in which the lower joint reinforcing bars 42B are installed so as to protrude from the floor F of the lower floor A.

First, the steel pipe installation process is performed.
The steel pipe 41 is installed so as to cover the plurality of lower joint reinforcing bars 42B arranged in the circumferential direction.

Next, a joining member installation step is performed.
As shown in FIG. 9(b), the joining member 3 is installed so that the closing plate 2 communicates with the steel pipe 41.

Next, a joining reinforcing bar installation process is performed.
The joining reinforcing bars 42 are installed so that the upper joining reinforcing bars 42A are arranged inside the steel pipe 41. The lower joint reinforcing bars 42B are placed above the cover plate 2.

Next, a beam joining process is performed.
The beam 1 is joined to the joining beam 1X of the joining member 3 with bolts or the like. Also, install floor deck plates.

Next, the concrete pouring process is carried out.
10(a), concrete is poured inside the steel pipe 41 and inside the closing plate 2. As a result, on the upper floor B, the lower connecting reinforcing bar 42B protrudes from the floor F.

Next, the above-mentioned steel pipe installation process, joint member installation process, joint reinforcing bar installation process, beam joining process, and concrete casting process are performed on the upper floor B.

In the construction method of the column-to-beam joint structure 100D and the column-to-beam joint structure configured in this way, the lower end portions 44b of the plurality of first inclined portions 44 are arranged in the region R2, and the plurality of lower end portions 44b are arranged in the region R3. By arranging the upper end portion 45u of the second inclined portion 45, shear reinforcement is achieved. Therefore, even if the steel pipe 41 reaches a high temperature during a fire, the filling concrete restraint effect can be maintained, and the shear transmission performance and axial force transmission performance of the column 4 can be ensured.

Further, there is no need to arrange reinforcing bars such as reinforcing bars inside the steel pipe 41 separately from the upper joining reinforcing bars 42A and the lower joining reinforcing bars 42B as in the prior art, and the workability is good.

Note that the assembly procedure shown in the above-described embodiments, the shapes and combinations of each component, etc. are merely examples, and various changes can be made based on design requirements and the like without departing from the gist of the present invention.

For example, in the embodiment shown above, 12 joining reinforcing bars 42 are arranged, but the number of joining reinforcing bars can be set as appropriate.

1... Beam 1X... Connection beam 2... Closing board (closing member)
3...Joining member 4...Column 5...Joint body 41...Steel pipe 42...Joining reinforcing bar 42A...Upper joining reinforcing bar 42B...Lower joining reinforcing bar 43...Vertical section 43A...Upper vertical section 43B...Lower vertical section 44...First inclined section (Upper slope)
45...Second slope part (lower slope part)
49... Concrete part 100, 100D... Joint structure F... Floor R1, R11 to R14... Vertical part arrangement area R2, R21, R22... First gathering area R3, R31, R32... Second gathering area

Claims (5)

A joint structure between a concrete-filled steel pipe column and a steel beam,
The pillars are
A steel pipe extending in a vertical direction;
A plurality of upper joint reinforcing bars arranged inside the steel pipe along a circumferential direction and extending downward from above the steel pipe;
A plurality of lower joint reinforcing bars are arranged inside the steel pipe along a circumferential direction and extend from below to above the steel pipe,
A plug member disposed in communication with the steel pipe;
A joint beam joined to the beam;
A concrete portion is filled in the inside of the steel pipe and the inside of the plugging member,
The joint beam and the closing member are integrally formed,
The upper joint reinforcing bar is
An upper vertical portion extending in a vertical direction;
an upper inclined portion provided below the upper vertical portion so as to be inclined with respect to the upper vertical portion;
The lower joint reinforcing bar is
A lower vertical portion extending in a vertical direction and disposed directly below the upper vertical portion;
A lower inclined portion is provided at an upper portion of the lower vertical portion so as to be inclined with respect to the lower vertical portion,
a lower end of the upper inclined portion is disposed lower than an upper end of the lower inclined portion,
A column-beam joint structure characterized in that, when viewed from the vertical direction, the multiple upper vertical portions and the multiple lower vertical portions are distributed and arranged in multiple vertical portion arrangement areas, the lower end of the upper inclined portion is arranged in a first concentration area between adjacent vertical portion arrangement areas, and the upper end of the lower inclined portion is arranged in a second concentration area different from the first concentration area between adjacent vertical portion arrangement areas. When viewed from the vertical direction, the plurality of upper slope portions are arranged to intersect in the first concentration region, and the plurality of lower slope portions are arranged to intersect in the second concentration region. The column-beam joint structure according to claim 1. The lower end of the upper inclined portion reaches the height of the upper end of the lower vertical portion,
3. A column-beam joint structure according to claim 1, wherein an upper end of the lower inclined portion reaches the height of a lower end of the upper vertical portion. A method for constructing a joint structure between a column and a beam according to any one of claims 1 to 3,
a steel pipe installation step of installing the steel pipe so as to surround the plurality of lower joint reinforcing bars extending upward from the floor surface;
A joined body in which the closing member and the connecting member having the connecting beam integrally molded with the closing member and joined to the beam, the upper connecting reinforcing bar and the lower connecting reinforcing bar are integrated, a joint installation process of installing the joint so that it communicates with the steel pipe;
a beam joining step of joining the beam to the joining beam;
A method for constructing a column-to-beam joint structure, comprising a concrete pouring step of pouring concrete inside the steel pipe and inside the closure member. A method for constructing a column-beam joint structure according to any one of claims 1 to 3, comprising:
a steel pipe installation step of installing the steel pipe so as to surround the plurality of lower joint reinforcing bars that extend upward from the floor surface;
a joining member installation step of installing a joining member having the closing member and the joining beam integrally molded with the closing member and joined to the beam so that the closing member communicates with the steel pipe;
a joining reinforcing bar installation step of installing joining reinforcing bars having the upper joining reinforcing bars and the lower joining reinforcing bars so that the lower joining reinforcing bars are arranged inside the steel pipe;
a beam joining step of joining the beam to the joining beam;
A method for constructing a column-to-beam joint structure, comprising: a concrete pouring step of pouring concrete inside the steel pipe and inside the closure member.

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