JP2019206876A - Joint structure of column and beam, and construction method of joint structure of column and beam - Google Patents

Abstract

To provide a joint structure of a column and a beam which has preferable workability while securing shear transmission performance and axial force transmission performance of the column in the case of a fire, and a construction method of the joint structure of the column and the beam.SOLUTION: In a joint structure 100 of a concrete-filled steel pipe construction column and a steel construction beam, a column 4 comprises: a vertically extending steel pipe 41; a plurality of joint reinforcements 42 disposed inside the steel pipe and extending vertically; a plurality of vertical reinforcement bars 47 disposed inside the steel pipe and extending vertically; and a plurality of shear reinforcement bars 48 bundling the plurality of vertical reinforcement bars. The joint structure further comprises: a closing member 2 connected to the steel pipe and provided so as to surround the joint reinforcements protruding from the column; a joint beam 1X constituted so as to be connected to the beam and provided between the beam and the closing member; and a concrete portion filled inside the steel pipe and inside the closing member. Neighboring joint beams are connected with each other via an outer diaphragm 21 disposed at an outside of a peripheral surface of the closing member.SELECTED DRAWING: Figure 1

Description

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

  Conventionally, connecting bars are arranged between columns and beams as a joint structure between concrete-filled steel pipe columns filled with concrete inside the steel pipes and reinforced concrete beams placed above and below the filled steel pipe concrete columns. In addition, a structure in which the connecting bars are fixed to concrete of columns and beams is known (see Patent Document 1 below).

  However, in the structure of Patent Document 1, since the beam is reinforced concrete, it takes time to construct the beam as compared with a steel beam, and the construction period becomes longer and the workability is poor.

  Therefore, a steel plate cover plate formed in a cylindrical shape is provided at the joint between the concrete-filled steel pipe column and the steel beam, and the steel beam is integrated with the cover plate so that the interior of the cover plate The structure which has arrange | positioned the joining rebar over the inside of a concrete filling steel pipe column is proposed.

  Further, a structure has been proposed in which a steel beam is welded to the side surface of a concrete-filled steel pipe column, and a reinforcing member composed of a reinforcing bar is arranged inside the column (see Patent Document 2 below).

Japanese Patent Laid-Open No. 1-125439 JP 2014-62379 A

  However, in the structure in which the cover plate is provided at the joint between the concrete-filled steel pipe column and the steel beam, if the steel pipe becomes hot during a fire, the effect of confining the filled concrete by the steel pipe decreases, and the shear transmission performance of the column and There is a problem that the axial force transmission performance is significantly reduced.

  Furthermore, in the structure of Patent Document 2, there is a problem in that the efficiency of concrete placing work is reduced because the steel beam is present at the position where the concrete is placed (in the pillar) in a plan view at the joint between the pillar and the beam. There is.

  Therefore, the present invention has been made in view of the above circumstances, and has a column-to-beam joint structure and a column-to-beam joint structure that have good workability while ensuring shear transmission performance and axial force transmission performance of the column at the time of a fire. The construction method of the joining structure is provided.

In order to achieve the above object, the present invention employs the following means.
That is, the connection structure of a column and a beam according to the present invention is a connection structure of a concrete-filled steel tube column and a steel frame beam, and the column includes a steel pipe extending in a vertical direction and an inside of the steel pipe. A plurality of joint reinforcing bars arranged and extending in the vertical direction; a plurality of vertical reinforcing bars arranged inside the steel pipe and extending in the vertical direction; and a plurality of shear reinforcing bars that bundle the plurality of vertical reinforcing bars. A blocking member that is connected to the steel pipe and that surrounds the joining reinforcing bar protruding from the column, and is configured to be connectable to the beam, and is provided between the beam and the blocking member. A connecting beam, and a concrete portion filled in the steel pipe and the blocking member, and the adjacent bonding beams are connected to each other through an outer diaphragm disposed outside the peripheral surface of the blocking member. Characterized by being connected It is.

In the joint structure of columns and beams constructed in this way, the vertical concrete reinforcement and shear reinforcement placed in the concrete-filled steel pipe column will prevent the filling concrete from being restrained even if the steel pipe becomes hot during a fire. It is possible to secure the shear transmission performance and axial force transmission performance of the column.
Further, the beam only needs to be joined to the joining beam with a bolt or the like, and it is not necessary to weld the beam to the column. Therefore, the beam can be easily installed, and the workability is good. Moreover, since the beam is a steel structure, it can be constructed in a shorter period of time than a reinforced concrete structure. Furthermore, since the flange of the steel beam does not exist inside the blocking member by adopting the outer diaphragm, it is possible to increase the amount of reinforcing bars of the joining reinforcing bars and to improve the bending strength of the columns. Further, since the joining beams are connected to each other via the outer diaphragm, the flange of the steel beam can be eliminated inside the blocking member, and there is a space when placing concrete in the steel pipe and the blocking member. It is ensured and concrete can be placed efficiently. For example, when filling concrete, the concrete filling performance can be improved by the work of a bar vibrator by human power, and a concrete hose having a large diameter can be used, and the concrete filling time can be shortened.

  Moreover, in the joining structure of the column and the beam according to the present invention, the steel pipe and the outer diaphragm may not be welded.

  In the joint structure between the column and the beam configured in this way, even if the steel pipe and the outer diaphragm are not welded together, the structural strength can be ensured and the welding work can be eliminated, so that the workability is improved. be able to.

  Moreover, in the joining structure of a column and a beam according to the present invention, only the web is arranged in the joining beam inside the pillar, and the adjacent joining beams are connected via the web. Good.

  In the joint structure between the column and the beam thus configured, the contribution of the web to the shear strength can be accumulated as the seismic performance, and the strength can be further increased. Moreover, since the web has a small area in plan view, concrete can be placed efficiently.

  Further, the 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 concrete-filled steel tubular column and a steel beam, and is provided at a joint portion between the pillar and the beam. The joining member to be arranged includes a blocking member formed in a cylindrical shape, and a joining beam configured to be able to be joined to the beam and provided between the beam and the blocking member, and adjacent to the joining. Beams are connected to each other via an outer diaphragm disposed outside the peripheral surface of the blocking member, and at a location where a plurality of joint reinforcing bars extending so as to protrude upward from the floor surface are provided, the joint reinforcing bars are A steel pipe installation step of installing a steel pipe so as to surround, a joining member installation step of installing the joining member so that the blocking member is connected to the steel pipe, a plurality of vertical reinforcing bars and the plurality of vertical reinforcing bars; Has multiple shear reinforcements to bundle A collective rebar installation process in which a collective rebar body in which reinforcing reinforcing bars and the joint rebar are assembled together is built in the steel pipe, a beam joining process in which the beam is joined to the joint beam, and the steel pipe And a concrete placing step of placing concrete inside the blocking member.

In the construction method of the joint structure between the column and the beam configured in this way, it is only necessary to install the assembled reinforcing bar body and the joining member that have been made into parts in the assembled reinforcing bar body installation process and the joining member installation process. And it can be constructed with labor saving.
In addition, the vertical reinforcement bars and shear reinforcement bars placed in the concrete-filled steel pipe columns maintain the effect of filling concrete restraint even when the steel pipe becomes hot during a fire, and the shear transmission performance and axial force transmission performance of the columns. Can be secured.
Furthermore, by adopting the outer diaphragm type, when the concrete is placed from above the joining member, the steel frame does not interfere, and as a result, the efficiency of the concrete placing operation can be improved. Moreover, since it can be built as a collective reinforcing bar which integrally assembled the joining reinforcing bar and the reinforcing reinforcing bar, the construction period can be shortened and the productivity can be improved.

  According to the construction method of the column-to-beam joint structure and the column-to-beam joint structure according to the present invention, the workability is good while securing the shear transmission performance and axial force transmission performance of the column in the event of a fire.

It is a figure which shows the joining structure of the pillar and beam which concern on one Embodiment of this invention, and is the perspective view which fractured | ruptured one part. It is a figure which shows the joining structure of the pillar and beam which concern on one Embodiment of this invention, (a) Vertical sectional view, (b) AA sectional view taken on the line of FIG. 2 (a), (c) FIG. It is BB sectional drawing of a). It is a front view which shows the reinforcement reinforcement body of the junction structure of the pillar which concerns on one Embodiment of this invention, and a beam. It is a figure which shows the construction method of the joining structure of the pillar and beam which concerns on one Embodiment of this invention, (a) It is a figure which shows a steel pipe installation process, (b) It is a figure which shows a joining member installation process, c) It is a figure which shows an aggregate reinforcement body installation process, (d) It is a figure which shows a concrete filling process, (e) It is a figure which shows a steel pipe installation process. It is a figure which shows the construction method of the joining structure of the pillar and beam different from FIG. 4, (a) It is a figure which shows an assembly reinforcement body installation process, (b) It is a figure which shows a steel pipe installation process, (c) It is a figure which shows a joining member installation process, (d) It is a figure which shows a beam joining process, (e) It is a figure which shows a concrete filling process, (f) It is a figure which shows an assembly reinforcing bar installation process, (g It is a figure which shows a steel pipe installation process. It is a horizontal sectional view (figure equivalent to Drawing 2 (b)) showing the junction structure of the pillar and beam concerning the modification of one embodiment of the present invention.

A column-to-beam joint structure according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a view showing a pillar-to-beam joint structure 100 according to an embodiment of the present invention, and is a perspective view with a part broken away. 2A and 2B are views showing a joint structure between a column and a beam according to an embodiment of the present invention, in which FIG. 2A is a vertical cross-sectional view, FIG. 2B is a cross-sectional view taken along line AA in FIG. FIG. 3 is a cross-sectional view taken along line BB in FIG.

In this embodiment, steel-framed beams are joined to the upper and lower parts of a concrete-filled steel pipe column. The beams are arranged orthogonal to the column in plan view.
As shown in FIG.1 and FIG.2, a pair of beam 1 is arrange | positioned so that it may orthogonally cross by planar view. In this embodiment, each beam 1 is comprised with the H-section steel.

  The beam 1 has a pair of flanges 11 that are spaced apart from each other in the vertical direction, and a web 12 that connects the pair of flanges 11 and 11 together. A joining member 3 is joined to the end face of each beam 1 by a bolt or the like.

  The joining member 3 has a joining beam 1X and a cover plate (block member) 2 and is integrally formed by welding or the like. The joint beam 1X is formed in the same cross-sectional shape as the beam 1. The flanges 11 of adjacent joining beams 1 </ b> X are connected by an outer diaphragm 21. The outer diaphragm 21 is integrated with the cover plate 2 by welding or the like.

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

  A cover plate 2 formed in a cylindrical shape is abutted and joined to an end portion (joint portion) of the web 12 of each joining beam 1X. The height of the cover plate 2 is substantially the same as the height of the beam 1.

  The cover plate 2 is arranged with its axis line directed in the vertical direction. The cover plate 2 is formed coaxially with the steel pipe 41 of the pillar 4 to be described later and substantially the same diameter, and is disposed immediately above and below the steel pipe 41.

  The column 4 includes a steel pipe 41, a joint reinforcing bar 42 and a reinforcing reinforcing bar 46 disposed inside the steel pipe 41, and a concrete portion 49 filled in the steel pipe 41.

  The steel pipes 41 are installed on both upper and lower sides with the beam 1 in between. The lower end 41b of the steel pipe 41 is merely installed on the upper surface of the beam 1 (the upper surface of the outer diaphragm 21), and is not welded. The lower surface of the beam 1 (the lower surface of the outer diaphragm 21) is placed in contact with the upper end 41u of the steel pipe 41 and is not welded.

A plurality of joining reinforcing bars 42 are arranged in the vertical direction and spaced in the circumferential direction.
The joining rebar 42 is inserted into the cylindrical cover plate 2 and extends from the upper steel pipe 41 to the lower steel pipe 41. In one steel pipe 41, the lower end 42 b of the upper joining rebar 42 and the upper end 42 u of the lower joining rebar 42 are arranged with a distance in the vertical direction at substantially the center in the length direction (vertical direction) of the steel pipe 41. ing.

FIG. 3 is a front view showing the reinforcing steel bar 46.
As shown in FIGS. 2 and 3, the reinforcing reinforcing bar body 46 includes a plurality of vertical reinforcing bars 47 and a plurality of shear reinforcing bars 48 that bundle the plurality of vertical reinforcing bars 47.

  A plurality of the vertical reinforcing bars 47 extend in the vertical direction and are arranged at intervals in the circumferential direction. In the present embodiment, the vertical reinforcing bars 47 are composed of four pieces. In addition, it is preferable that the vertical reinforcement bar 47 is comprised by about 4-8 pieces.

  Each shear reinforcing bar 48 is arranged along the horizontal direction and bundles a plurality of vertical reinforcing bars 47. The shear reinforcement bars 48 are spaced apart in the vertical direction and are arranged at substantially equal intervals.

  The reinforcing reinforcing bar 46 is installed at a position where the lower end corresponds to the upper surface of the beam 1. In the present embodiment, the lower end 47b of the vertical reinforcing bar 47 is installed at a position corresponding to the upper surface of the flange 11 on the upper side of the beam 1 (joining beam 1X). The upper end 47 u of the vertical reinforcing bar 47 is positioned slightly below the lower flange 11 of the beam 1. In the present embodiment, the jointed reinforcing bar body 42 and the reinforcing reinforcing bar body 46 are referred to as a collective reinforcing bar body 50.

  The concrete portion 49 is filled in the steel pipe 41 and the cylindrical cover plate 2. The joint reinforcing bar 42 and the reinforcing reinforcing bar body 46 (the aggregate reinforcing bar body 50) are fixed to the concrete portion 49.

Next, a construction method of the joint structure 100 between the column 4 and the beam 1 will be described.
FIG. 4 is a diagram showing a construction method of the joint structure 100 between the column 4 and the beam 1, (a) a diagram showing a steel pipe installation process in the lower floor A, and (b) a joint member installation process in the lower floor A. (C) It is a figure which shows the assembly reinforcement body installation process in the lower floor A, (d) It is a figure which shows the concrete filling process in the lower floor A, (b) The steel pipe installation process in the upper floor B FIG. In FIG. 4, the number of reinforcing bars is simplified.

First, when the lower floor A is the lowermost floor, the joint reinforcing bar installation process is performed on the lower floor A.
As shown in FIG. 4A, the joint reinforcing bar 42 is installed on the floor F of the lower floor A. For example, when the floor F of the lower floor A is constructed, the joint rebar 42 is installed so as to protrude from the floor, and floor concrete is placed. The joining reinforcing bars 42 are arranged along the vertical direction, and a plurality of joining reinforcing bars 42 are arranged at intervals in the circumferential direction.

Next, a steel pipe installation process is performed.
The steel pipe 41 is installed so as to cover the plurality of joining reinforcing bars 42 arranged in the circumferential direction.

Next, a joining member installation process is performed.
As shown in FIG. 4B, the joining member 3 in which the cover plate 2 formed in a cylindrical shape is joined to the end of the joining beam 1 </ b> X is installed on the upper portion of the steel pipe 41. At this time, the cover plate 2 is installed so as to communicate with the steel pipe 41.

Next, a collective reinforcing bar installation process is performed.
As shown in FIG. 4C, the collective reinforcing bar body 50 in which the joining reinforcing bars 42 and the reinforcing reinforcing bar bodies 46 are integrated is moved downward from above the cover plate 2. The collective rebar 50 is installed such that the lower end of the reinforcing reinforcing bar 46 (the lower end 47b of the vertical reinforcing bar 47) is located on the upper surface of the floor F and the upper end 42u of the joining reinforcing bar 42 protrudes from 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 a bolt or the like. Further, a floor deck plate 51 is laid.

Next, a concrete placing process is performed.
As shown in FIG. 4 (d), concrete is placed in the steel pipe 41 and the cover plate 2 to form a concrete portion 49. At the same time, concrete is also cast on the upper surface of the floor deck plate 51 to construct the floor surface.

Next, in the upper floor B, a steel pipe installation process is performed.
As shown in FIG.4 (e), in the upper floor B, the steel pipe 41 is installed so that the some joint reinforcement 42 arrange | positioned in the circumferential direction may be covered.
Subsequently, the above-described joining member installation process, aggregated reinforcing bar installation process, beam joining process, and concrete placing process are performed on the upper floor B. Henceforth, the joining structure 100 of the pillar 4 and the beam 1 can be constructed by repeating the same process.

  In the construction method of the joint structure 100 of the column 4 and the beam 1 and the joint structure 100 of the beam 1 thus configured, the vertical reinforcing bar 47 and the shear reinforcing bar 48 arranged in the column 4 of the concrete-filled steel pipe structure. Thereby, even if the steel pipe 41 becomes high temperature at the time of a fire, the filling concrete restraint effect is maintained and the shear transmission performance and the axial force transmission performance of the column 4 can be ensured.

  Further, the beam 1 only needs to be joined to the joining beam 1X with a bolt or the like, and it is not necessary to weld the beam 1 to the column 4, so that the beam 1 can be easily installed and the workability is good. Furthermore, since the beam 1 has a steel structure, it can be constructed in a shorter period of time than a reinforced concrete structure.

  Further, since the vertical spacing of the shear reinforcement bars 48 is substantially uniform, even if the steel pipe 41 becomes high temperature in the event of a fire, the filling concrete restraining effect is maintained over the entire length of the column 4, and the shear transmission performance of the column 4 and Axial force transmission performance can be ensured over the entire length of the column 4.

  Moreover, in the collective reinforcing bar installation process and the joining member installation process, it is only necessary to install the collective reinforcing bar 50 and the joining member 3 that have been made into parts in advance, so that it is possible to shorten the work period and save labor.

  Furthermore, since the flange of the steel beam does not exist inside the blocking member 2, the amount of reinforcing bars of the joining reinforcing bars 42 can be increased, and the bending strength of the columns can be improved. And since the joining beams 1X are connected to each other via the outer diaphragm 21, the flange of the steel beam can be eliminated inside the blocking member 2, and concrete is placed inside the steel pipe 41 and the blocking member 2. In this case, a space is secured and the concrete can be placed efficiently. For example, when filling concrete, the concrete filling performance can be improved by the work of a bar vibrator by human power, and a concrete hose having a large diameter can be used, and the concrete filling time can be shortened.

(Another construction method)
FIG. 5 is a diagram showing a construction method of a joint structure between a column and a beam different from that in FIG. 4, (a) a diagram showing a set reinforcing bar installation process in the lower floor A, and (b) in the lower floor A. It is a figure which shows a steel pipe installation process, (c) It is a figure which shows the joining member installation process in lower floor A, (d) It is a figure which shows the beam joining process in lower floor A, (e) Concrete in lower floor A It is a figure which shows a filling process, (f) It is a figure which shows the aggregate reinforcement body installation process in the upper floor B, (g) It is a figure which shows the steel pipe installation process in the upper floor B.

First, when the lower floor A is the lowermost floor, the joint reinforcing bar installation process is performed on the lower floor A.
As shown in FIG. 5A, the joint reinforcing bar 42 is installed on the floor F of the lower floor A. For example, when the floor F of the lower floor A is constructed, the joint rebar 42 is installed so as to protrude from the floor, and floor concrete is placed. The joining reinforcing bars 42 are arranged along the vertical direction, and a plurality of joining reinforcing bars 42 are arranged at intervals in the circumferential direction.

Next, a collective reinforcing bar installation process is performed.
From the upper side of the joint reinforcing bar 42 installed on the floor F, the collective reinforcing bar body 50 in which the joint reinforcing bar 42 and the reinforcing reinforcing bar body 46 are integrated is moved downward. The collective reinforcing bar 50 is installed such that the lower end of the reinforcing reinforcing bar 46 (the lower end 47b of the vertical reinforcing bar 47) is positioned on the upper surface of the floor F.

Next, a steel pipe installation process is performed.
As shown in FIG. 5 (b), the steel pipe 41 is installed so as to cover the plurality of joint reinforcing bars 42 and the collective reinforcing bars 50 arranged in the circumferential direction.

Next, a joining member installation process is performed.
As shown in FIG. 5 (c), the joining member 3 in which the cover plate 2 formed in a cylindrical shape is joined to the end of the joining beam 1 </ b> X is installed on the upper portion of the steel pipe 41 after inserting the joining rebar 42. To do. The cover plate 2 is installed so as to communicate with the steel pipe 41.

Next, a beam joining process is performed.
As shown in FIG. 5D, the beam 1 is joined to the joining beam 1X of the joining member 3 with a bolt or the like. Further, a floor deck plate 51 is laid.

Next, a concrete placing process is performed.
As shown in FIG. 5 (e), concrete is placed in the steel pipe 41 and the cover plate 2 to form a concrete portion 49.

Next, in the upper floor B, a collective reinforcing bar installation process is performed.
As shown in FIG. 5 (f), on the upper floor B, the collective reinforcing bars 50 are installed from above the plurality of joint reinforcing bars 42 arranged in the circumferential direction.
Subsequently, the steel pipe installation step (FIG. 5G), the joining member installation step, the beam joining step, and the concrete placing step are performed on the upper floor B. Henceforth, the joining structure 100 of the pillar 4 and the beam 1 can be constructed by repeating the same process.

(Modification)
Next, a modified example of the joint structure 100 between the column 4 and the beam 1 according to an embodiment of the present invention will be described with reference to FIG.
In the following embodiments, the same members as those used in the above-described embodiments are denoted by the same reference numerals, and the description thereof is omitted.

FIG. 6 is a horizontal cross-sectional view (a diagram corresponding to FIG. 2B) of a joint structure between a column and a beam according to a modification of the above embodiment.
As shown in FIG. 6, in this modification, the web 12 of the joining beam 1 </ b> X extends to the inside of the cover plate 2, and the webs 12 are connected to each other inside the cover plate 2. In addition, the flange of the joining beam 1X is not formed inside the cover plate 2.

  By configuring in this way, the contribution of the web 12 to the shear strength can be accumulated as the seismic performance, and higher strength can be achieved. Further, since the web 12 has a small area in plan view, the concrete can be placed efficiently.

  It should be noted that the assembling procedure shown in the above-described embodiment, the various shapes and combinations of the constituent members, and the like are merely examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

  For example, the reinforcing reinforcing bar body 46 is arranged inside the joining rebar 42 in a plan view, but the present invention is not limited to this, and if there is a sufficient space between the joining rebar 42 and the steel pipe 41, the plan view 2 may be arranged outside the joining rebar 42 and inside the steel pipe 41.

DESCRIPTION OF SYMBOLS 1 ... Beam 1X ... Joining beam 2 ... Cover plate (block member)
DESCRIPTION OF SYMBOLS 3 ... Joining member 4 ... Column 21 ... Outer diaphragm 41 ... Steel pipe 42 ... Joining reinforcement 46 ... Reinforcement reinforcement 47 ... Vertical reinforcement reinforcement 48 ... Shear reinforcement reinforcement 49 ... Concrete part 50 ... Assembly reinforcement 100 ... Joining structure A ... Lower floor B ... Upstairs

Claims (4)

It is a joint structure between a concrete-filled steel tube column and a steel beam,
The pillar is
A steel pipe extending in the vertical direction;
A plurality of joint reinforcing bars arranged inside the steel pipe and extending in the vertical direction;
A plurality of vertical reinforcing bars arranged in the steel pipe and extending in the vertical direction;
A plurality of shear reinforcement bars for bundling the plurality of vertical reinforcement bars;
A blocking member that is connected to the steel pipe and is provided so as to surround the joining reinforcing bar protruding from the column;
A connecting beam configured to be connectable to the beam and provided between the beam and the blocking member;
A concrete portion filled in the steel pipe and the cap member, and
Adjacent joining beams are connected to each other via an outer diaphragm disposed outside the peripheral surface of the blocking member.   The column-beam connection structure according to claim 1, wherein the steel pipe and the outer diaphragm are not welded to each other.   3. The column and beam according to claim 1, wherein only the web is arranged in the column, and the adjacent beam is connected via the web. 4. Bonding structure with. A method of constructing a joint structure between a concrete-filled steel tubular column and a steel beam,
A joining member disposed at a joining portion between the column and the beam is a tubular member formed in a cylindrical shape, and a joining beam provided between the beam and the shielding member so as to be joined to the beam. And the adjacent joint beams are connected via an outer diaphragm disposed on the outer side of the peripheral surface of the blocking member,
A steel pipe installation step of installing a steel pipe so as to surround the joint rebar at a location where a plurality of joint rebars extending so as to protrude upward from the floor surface are provided;
A joining member installation step of installing the joining member such that the blocking member is connected to the steel pipe;
A collective rebar in which a reinforcing bar having a plurality of vertical reinforcing bars and a plurality of shear reinforcing bars that bundle the plurality of vertical reinforcing bars and the joint reinforcing bar are assembled into the steel pipe. Body installation process,
A beam joining step for joining the beam to the joined beam;
And a concrete placing step for placing concrete in the steel pipe and in the blocking member.

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