JP2017179997A - Column-beam joint structure and construction method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a column-beam joint structure having a mechanical joint in a column-beam joint part, the structure suppressing damaging of concrete when a beam main reinforcement yields.SOLUTION: A beam main reinforcement (18a) of a beam (13a) extending in a prescribed direction (X-direction) is connected by a mechanical joint (21) in a column-beam joint part (14). A stirrup-direction shear reinforcement (22) for reinforcing the column-beam joint part is disposed in a same direction as a stirrup (19) of the beam, including a vertical direction. At a time of large-scale earthquake, force is exerted in a direction opposite of the X-direction to each of the beam main reinforcements disposed on top and bottom. A damage on concrete aggravates when an adhesion between the beam main reinforcement and the concrete is broken by the force and the beam main reinforcement slides on the concrete. The shear reinforcement provided on the top and bottom resists the force, and suppresses breaking of the adhesion between the beam main reinforcement and the concrete.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to a column beam joint structure and a construction method thereof, and particularly to a column beam joint structure having a mechanical joint in a column beam joint portion and a construction method thereof.

  FIG. 9 is a front view of a beam-column joint structure 1 in a conventional reinforced concrete building, and the concrete portion is shown with lines on the outer surface, but the inner concrete is omitted. The column 2 has column main bars 3 and band bars 4, and the beam 5 has beam main bars 6 and rib bars 7. In the column beam joint 8, the column main reinforcement 3 and the beam main reinforcement 6 are arranged so as to cross each other, and the shear reinforcement 9 is arranged in parallel with the band reinforcement 4.

  In addition, a method of connecting beam main bars with mechanical joints has been proposed. For example, in Patent Document 1, a mechanical joint that connects beam main bars in one direction at a joint between a beam and a column that extends in a cross direction in a plan view, and a machine that connects beam main bars that extend in the other direction. It has been proposed to arrange it at a position that does not overlap vertically with respect to the type joint. Moreover, in the beam-column joint structure described in Patent Document 1, the shear reinforcement bars at the joint are arranged in parallel with the band bars. According to Patent Document 1, in such a structure, the vertical displacement of the beam main bars is small and the effective beam is large, compared to the case where the mechanical joints overlap vertically.

  On the other hand, Patent Document 2 proposes that a beam main bar made of high-strength reinforcing bars and a beam main bar made of ordinary reinforcing bars are connected by a mechanical joint at an intermediate position of the beam, not at the beam-column joint. In the column-beam joint structure described in Patent Document 2, the shear reinforcement bars at the joint are arranged in parallel with the stirrups. The beam described in Patent Document 2 is a crane after separately assembling a beam constituent unit including a beam main bar and a stirrup bar made of high-strength reinforcing bars and a beam constituent unit including a beam main bar and a stirrup bar consisting of ordinary reinforcing bars. Etc., and is constructed by connecting with mechanical joints. According to Patent Document 2, such a structure reduces the beam component unit and improves the workability.

JP-A-8-105119 JP2015-14097A

  In general, the column beam structure is designed in a beam yield type so that the yield of the column is prevented even when a large earthquake occurs. Therefore, at the time of a large earthquake, the column main reinforcement does not yield, and the beam main reinforcement yields at the beam end near the column, resulting in a large strain in the beam main reinforcement in the column beam joint. For example, as shown in FIG. 9, when the beam reinforcement at the beam-column joint is through (reinforcing the reinforcement), the bond between the beam reinforcement and the concrete breaks, and the beam reinforcement is made of concrete. It will grow while sliding. At this time, since the distance between adjacent beam main bars in the beam width direction is relatively small, horizontal cracks occur between adjacent beam main bars.

  In addition, when the mechanical joint is located in the beam-column joint, the edge of the mechanical joint pushes the concrete, and in the case of a mechanical joint with a large diameter, the distance between adjacent mechanical joints is between the beam main bars. There is a possibility that damage to the concrete in the beam-column joint is increased because it is further smaller than the distance between the two and the adhesion resistance increases due to the large surface area.

  The present invention has been made in view of such a background, and an object of the present invention is to suppress damage to concrete caused when a beam main bar yields in a beam-column joint structure having a mechanical joint in a beam-column joint. To do.

  In at least some embodiments of the present invention, a mechanical joint (21) connecting a beam main bar (18a) of a beam (13a) extending in a predetermined direction (X direction) is provided in a column beam joint (14). The beam main reinforcement of the beam is arranged in at least two upper and lower stages, and the shear reinforcement reinforcing the beam-to-column connection is provided in the column (12). It is characterized in that it includes a rib-direction shear reinforcement bar (22) having a portion extending between the column main bars (15) arranged on the outermost side in the direction of and extending in the vertical direction. Here, the “vertical direction” means the direction connecting the beam main bar on the upper side and the beam main bar on the lower side in the vertical direction or the most aligned position in the vertical direction, and depending on the relationship with other members Including the case of tilting or bending with respect to the exact vertical direction.

  According to this structure, even if the main beam bars arranged vertically are subjected to forces in the X direction due to the shaking of the columns in the event of a large earthquake, the shear shear reinforcement bars extend in the vertical direction. It is possible to prevent the beam main bar and the mechanical joint from being attached to the concrete and to prevent the beam main bar and the mechanical joint from sliding against the concrete, thereby preventing the concrete from being damaged.

  At least some embodiments of the present invention are characterized in that, in the above configuration, the beam is made of precast concrete.

  According to this configuration, workability at the construction site can be improved and the work period can be shortened.

  In at least some embodiments of the present invention, in the above configuration, the shear reinforcement bars are arranged between the beam main bars arranged above and below and parallel to a plane perpendicular to the extending direction of the main bars of the column. And further comprising a band-direction shear reinforcement.

  According to this configuration, the shear reinforcement bars are also arranged in the joint portion in the direction parallel to the column strips, and the shear strength can be further improved.

  At least some embodiments of the present invention include two first beam members (25a) made of precast concrete that include the step of erecting a column (12) and beam main bars (18a) arranged in at least two upper and lower stages. Are disposed so that both sides of the column are linear and one end side of each column is positioned at a joint (14) with the column, and a mechanical joint ( 21) connecting the beam main bars of the two first beam members to each other, installing a shear reinforcement bar at the joint, and placing concrete at the joint, In the step of installing the shear reinforcement, the rib-direction shear reinforcement (22) having a portion extending in the vertical direction and extending in a direction parallel to a plane perpendicular to the beam principal reinforcement is provided with the beam reinforcement or the beam reinforcement. Characterized in that it comprises a step of assembling a position to be in contact with or close to the mechanical coupling.

  According to this structure, a column beam joint structure provided with the above-mentioned effect can be constructed.

  At least some embodiments of the present invention are characterized in that, in the above configuration, the step of assembling the loose shear reinforcement is performed before the step of arranging the beam member.

  According to this configuration, since the loose shear reinforcing bars installed in a relatively narrow space can be assembled on the ground of a factory or a construction site, work efficiency can be improved.

  At least some embodiments of the present invention may further include the step of installing a second beam member (25b) arranged in a direction intersecting the first beam member with respect to the column in the above configuration. The step of arranging the two beam members is performed before the step of arranging the first beam member, and the main beam (18b) of the second beam member at the joint is a through bar, and the shear shear reinforcement is performed. The step of assembling the line is performed on the second beam member before the step of arranging the second beam member.

  According to this configuration, even when the beams cross at the joint, the loose shear reinforcement bars can be assembled on the ground of the factory or construction site, and work efficiency can be improved.

  In the beam-column joint structure having a mechanical joint in the beam-column joint, it is possible to suppress damage to the concrete that occurs when the beam main bar yields.

Plan view of a beam-column joint structure according to an embodiment 1 is a partial cross-sectional front view taken along line II-II in FIG. Partial cross-sectional side view along line III-III in FIG. Explanatory drawing showing the force and strain generated at the beam-column joint Plan view of a column beam having a column beam connection structure according to an embodiment The figure which shows the construction procedure of the column beam connection structure which concerns on embodiment Enlarged plan view of a beam applied to a column beam connection structure according to an embodiment Plan view of a beam-column joint structure according to a modification of the embodiment Front view of column beam structure according to prior art

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, a column beam joint structure 11 according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3, the outer surface of the concrete is indicated by a line, but the illustration of the inner concrete is omitted. 1 is referred to as the X direction, the vertical direction of the paper surface of FIG. 1 is referred to as the Y direction, and the direction orthogonal to the paper surface of FIG. 1 is referred to as the Z direction. The X direction and the Y direction are directions parallel to the horizontal plane orthogonal to each other, and the Z direction coincides with the vertical direction.

  A column beam connection structure 11 according to an embodiment of the present invention is a structure of a joint portion 14 between a column 12 and a beam 13 in an intermediate floor of a reinforced concrete building, and is mainly characterized by the arrangement of shear reinforcement bars. . Although the concrete of the joint portion 14 is placed at the construction site, the column 12 and the beam 13 may be made of precast concrete or may be placed at the site, respectively.

  The column 12 includes column main bars 15 extending in the vertical direction, band bars 16 that surround all the column main bars 15 and are in contact with the column main bars 15 arranged outside, and some column main bars. 15 and an accessory ligament 17 arranged in a core shape so as to surround 15. The band 16 and the auxiliary band 17 are arranged so as to extend in a direction parallel to a plane orthogonal to the columnar bars 15, that is, in the horizontal direction.

  The beam 13 extending in the X direction is referred to as a first beam 13a, and the beam 13 extending in the Y direction is referred to as a second beam 13b. However, when it is not necessary to distinguish between them, the beam 13 is simply referred to as a beam 13 (hereinafter referred to as the beam 13). The same applies to the beam main reinforcement 18 described below). The beam 13 includes a beam main bar 18 extending along the extending direction of the beam 13, and a rib bar 19 arranged so as to surround all the beam main bars 18 and abut on the beam main bars 18 arranged on the outside. , And a secondary stirrup 20 arranged in a core shape so as to surround some of the beam main bars 18. The main beam 18 is arranged in two or more stages. In the present embodiment, the main beam bars 18 are arranged in two stages on the upper side and two stages on the lower side, for a total of four stages. The stirrup 19 and the secondary stirrup 20 are arranged so as to extend in a direction parallel to a plane orthogonal to the extending direction of the beam main bar 18.

  In the joint portion 14, the main beam bar 18 a of the first beam 13 a is connected by a mechanical joint 21. As the mechanical joint 21, for example, a screw thread is provided at the end of the beam main bar 18a, a thread groove is provided on the inner surface of the steel pipe, and the both are screwed together. Known means such as a means for filling a filler such as a resin or a means for using both in combination can be applied. The beam main bar 18b of the second beam 13b is a through bar, but may be changed to one connected by any known joint.

  Further, the joint 14 surrounds the beam main bars 18a of all the first beams 13a, and is arranged in a shear direction so as to be in contact with or close to the beam main bars 18a or the mechanical joints 21 arranged on the outermost side. Surrounding the reinforcing bars 22, the rib-direction secondary shear reinforcing bars 23 arranged in contact with or close to the beam main bars 18 a of some of the first beams 13 a or the mechanical joints 21, and all the column main bars 15, the outermost side And a band direction shear reinforcement bar 24 arranged so as to abut on the column main bar 15 arranged in the vertical direction. The rib-direction shear reinforcement bar 22 and the rib-direction secondary shear reinforcement bar 23 are parallel to the plane defined by the rib bar 19 of the first beam 13a so as to include a portion extending in the vertical direction, and X of the column 12 It arrange | positions between the column main reinforcements 15 arrange | positioned in the outermost direction. It is preferable that the rib direction shear reinforcement bar 22 is provided at a position that substantially matches the rib bar 19 of the first beam 13a in the X direction. More specifically, the rib direction shear reinforcement bar 22 has a rectangular shape extending in the Y direction and the Z direction, and the rib direction secondary shear reinforcement bar 23 is formed with hooks at both ends and extends in the Z direction. Although it has a straight line shape, these shapes can be appropriately changed within a range provided so as to connect the beam main bars 18a arranged above and below. The band direction shear reinforcement bar 24 is disposed between the beam main bars 18 disposed in parallel with the plane defined by the band bar 16 and at the uppermost and lower positions in the Z direction. The band direction shear reinforcing bar 24 is preferably provided at a position that substantially matches the band bar 16 in the Z direction. Note that one or both of the rib-direction secondary shear reinforcement bars 23 and the band-direction shear reinforcement bars 24 may be omitted, and may be in contact with or close to some column main bars 15 and defined by the band bars 16. A belt-direction secondary shear reinforcement bar arranged parallel to the plane may be provided. Further, when the beam main bar 18b of the second beam 13b is deformed so as to be connected by the mechanical joint 21 in the joint portion 14, the rib direction shear reinforcing bar 22 and the rib direction secondary shear bar 23 are connected to the second beam. It is preferable to provide also in the direction parallel to the plane defined by the stirrup 19 of the 13b.

  By providing the mechanical joint 21 in the joint portion 14, it is possible to obtain a high-quality first beam 13a having no joint portion in the member. In addition, when the first beam member 25a made of precast concrete is used, the cast-in portions are gathered at the joint portion 14, the priority part of quality control becomes clear, and quality control can be reliably performed. Since the first beam 13a does not have a splicing portion, there is no finishing work such as partial reinforcement, formwork, and post-tilting of tiles, and the influence on the construction plan and provisional design image can be reduced.

  When a large earthquake occurs, in the beam-column joint structure 11, the beam main reinforcement 18 yields in the vicinity of the column surface of the column 12, and the beam main reinforcement 18 arranged in each of the upper and lower stages is opposite to each other according to the shaking of the column 12. Directional force is added. Paying attention to the main beam bar 18a of the first beam 13a, the upper and lower beam main bars 18a receive forces opposite to each other in the X direction. At this time, since the rib direction shear reinforcement bar 22 and the rib direction secondary shear bar 23 are arranged so as to include a portion extending in the vertical direction, this force is resisted and adhesion between the beam main bar 18a and the concrete is prevented. It cuts and it suppresses that beam main reinforcement 18a slips on concrete. Further, since the rib-direction shear reinforcement bar 22 and the rib-direction secondary shear reinforcement bar 23 are also arranged in the vertical direction in the vicinity of the mechanical joint 21, the mechanical joint 21 having a smoother surface than the beam main bar 18 a is used as the concrete. Suppresses and slips off the adhesion. Since slip of the beam main reinforcement 18a and the mechanical joint 21 is suppressed, it is possible to suppress vertical cracks generated in the concrete due to the slip and damage to the concrete caused by the concrete joints pushing out the concrete. The same effect as that of the main beam 18a of the first beam 13a in the X direction can be obtained with respect to the main beam 18b of the second beam 13b in the Y direction.

  In the joint in the prior art, the shear reinforcement bars are arranged only in the band direction. However, since the mechanical joints 21 are thicker than the beam main bars 18a, the shear reinforcement bars are concentrated in a narrow space between the upper and lower mechanical joints 21. There was a problem that. In the above-described embodiment of the present invention, since the shear reinforcement bars are mainly provided in the same direction as the extending direction of the ribs 19, the shear reinforcement bars can be distributed and arranged in the entire joint portion. 22, the rib-direction secondary shear reinforcement bar 23 and the band-direction shear reinforcement bar 24 ensure the amount of shear reinforcement required for the joint as a whole, and secure the shear strength of the joint 14.

  With reference to FIG. 4, the significance of disposing the shear shear reinforcement 22 in the joint 14 having the mechanical joint 21 will be described. FIG. 4 is a diagram schematically showing the force F and strain ε generated at the joints 8 and 14 during an earthquake. In the prior art in which the joint 8 does not have the mechanical joint 21, a tensile force Ft corresponding to the bending moment is applied to the beam main reinforcing bar 6, but the diameter of the beam main reinforcing bar 6 that is a through bar and the surface unevenness are uniform. Therefore, as shown in FIG. 4A, the strain ε distribution of the beam main reinforcement 6 has a distribution shape that is the largest at the beam end. Adhesive force Fa acts between the beam main reinforcement 6 in the joint 8 and the concrete, and the tensile force Ft of the beam main reinforcement 6 is transmitted to the concrete. Since the adhesion resistance depending on the diameter of the beam main reinforcement 6 and the surface irregularities is uniform, a uniform force is transmitted to the concrete. For this reason, the joint part 8 as a whole resists damage, and the concrete damage of the joint part 8 tends to be dispersed.

  On the other hand, when the mechanical joint 21 is present, the cross-sectional area, diameter, and outer peripheral surface area of the mechanical joint 21 are larger than those of the beam main bar 18, so that the situation shown in FIG. The strain ε of the beam main bar 18 is concentrated at the end. In the mechanical joint 21 portion, since the sectional area is large, the strain is small, but since the surface area is large, the adhesion resistance is increased, and as a result, a large force acts on a narrow range of concrete. Therefore, as shown in FIG. 4C, a shear shear reinforcement 22 is provided to resist the force. In addition, since a force (support pressure) Fc for pressing the concrete acts on the fore end portion of the mechanical joint 21, the concrete shear reinforcement 22 is installed outside the mechanical joint 21 in the joint portion 18. Damage can be suppressed.

  As described above, when the mechanical joint 21 is provided in the joint portion 18, the force acting on the concrete in the joint portion 18 is concentrated in the vicinity of the surface of the mechanical joint 21 and the fore edge portion as compared to the bar arrangement. Therefore, the joint portion 18 is easily damaged. Therefore, by providing the rib-direction shear reinforcement 22, the rib-direction shear reinforcement 22 resists adhesion split cracks generated by the adhesion force in the vicinity of the outer surface of the mechanical joint 21, and in the vicinity of the small edge portion of the mechanical joint 21. It resists adhesion split cracks and constrains the concrete portion where the bearing pressure is generated, thereby exerting the effect of expanding the effective resistance volume in the concrete in the joint 18. It should be noted that at the joint portion where the bearing pressure acts, the rib-direction shear reinforcement bar 22 may be arranged so as to abut against the beam main bar 18 (the rib-direction shear reinforcement bar 22 at the left end in FIG. 4). In order to be close to each other in a separated state, for example, the rib-direction shear reinforcement bars 22 in contact with the mechanical joint 21 may be arranged so as to be aligned with the X-direction (the rib-direction shear reinforcement at the right end in FIG. 4). Muscle 22).

  Next, with reference to FIGS. 5-7, the construction method of the column beam connection structure 11 is demonstrated to the case where the beam 13 is precast concrete. FIG. 6 shows each member in a simplified manner.

  As shown in FIG. 6A, first, the pillar 12 is erected. The pillar 12 may be made of precast concrete or cast on site.

  The following operations are performed on the ground of the factory or the construction site before or after the pillar 12 is erected or simultaneously with the erection of the pillar 12. The first beam 13a is composed of two first beam members 25a made of precast concrete to which the beam main bar 18a is connected at the joint portion 14, and the mechanical joint 21 is connected to the end of the beam main bar 18a of one first beam member 25a. Temporarily assembled to the part. As shown in FIG. 7, the second beam 13 b is composed of a second beam member 25 b in which the beam main bar 18 b of the joint 14 is a through bar. Depending on the weight of the second beam member 25b and the lifting capacity of the crane for installing the second beam member 25b, the other end of the second beam member 25b is connected to another second beam at the intermediate portion of the second beam 13b. A joint connected to the member 25b is provided. Further, the loose direction shear reinforcement 22 is assembled. The disassembly direction shear reinforcement bar 22 is assembled to the beam main bar 18b of the second bar member 25b. First, a setup bar 29 is installed in a horizontal direction perpendicular to the beam main bar 18b. When the discontinuous shear reinforcing bar 22 is assembled to the setup bar 29 and the second beam member 25b and the first beam member 25a are arranged at the target positions with respect to the column 12, the discontinuous shear reinforcing bar 22 becomes the first beam member. It is made to contact | abut or adjoin to the beam main reinforcement or the mechanical coupling 21 of 25a. The setup bar 29 may be a rebar thinner than the loose shear reinforcement bar 22. In addition, it is preferable that the rib-direction secondary shear reinforcing bar 23 is also assembled to the setup bar 29 at this stage (not shown). Further, the band-direction shear reinforcement bar 24 is arranged at a predetermined position of the second beam member 25b by using a wire or a setup bar (not shown).

  Next, as shown in FIG. 6B, the second beam member 25 b is arranged at a target position with respect to the column 12. Next, as shown in FIG. 6C, the two first beam members 25 a are arranged at target positions with respect to the column 12. At this time, in order to cross the beam main bars 18 of the first beam member 25a and the second beam member 25b, the first beam member 25a is lifted to a predetermined height and then moved in the X direction.

  Next, as shown in FIG. 6D, the beam main bars 18a of the two first beam members 25a are connected by the mechanical joint 21 that has been temporarily assembled. Further, the position of the assembled shear reinforcing bar 22 is adjusted to be brought into contact with or close to the beam main bar 18a or the mechanical joint 21 of the first beam member 25a. Further, the position of the rib-direction secondary shear reinforcement bar 23 is adjusted so as to come into contact with or close to the beam main bar 18a or the mechanical joint 21 of the first beam member 25a, and the position of the band-direction shear reinforcement bar 24 is adjusted. In addition, instead of assembling part or all of the band-direction shear reinforcing bar 24 to the second beam member 25b before being attached to the column 12, it may be assembled to the column main bar 15 at this stage.

  Finally, as shown in FIG. 6 (e), concrete is placed in the joint 14.

  In addition, before the beam member 25 is installed, the loose direction shear reinforcement bar 22 and the loose direction secondary shear reinforcement bar 23 are not assembled, and after the beam member 25 is installed, the loose direction shear reinforcement bar 22 and the loose direction secondary shear reinforcement bar 23 are connected. It may be assembled. When the second beam 13b is not provided, the loose direction shear reinforcement bar 22 and the loose direction secondary shear reinforcement bar 23 are assembled to the beam main bar 18a of the first beam member 25a or the mechanical joint 21, and then the first beam member. 25a may be arranged with respect to the pillar 12. When the second beam 13b is deformed so that the beam main reinforcement 18b is joined in the joint portion 14, the assembly of the shear shear reinforcement 22 is performed by arranging the first beam member 25a and the second beam member 25b on the column 12. May be performed on the beam main bar 18a or the mechanical joint 21 of the first beam member 25a, or may be performed on the setup bar 29 after the setup bar 29 is provided on the second beam member 25b.

  In the prior art, the shear reinforcement bars are arranged only in the band direction. However, since the mechanical joints 21 are thicker than the beam main bars 18a, the shear reinforcement bars need to be concentrated in a narrow space between the upper and lower mechanical joints 21. The construction was difficult. In the above-described embodiment of the present invention, since the shear reinforcement bars are provided mainly in the same direction as the extending direction of the ribs 19 of the first beam 13a, it is easy to adjust the engagement with other members. Moreover, since the rib direction shear reinforcement 22 and the rib direction secondary shear reinforcement 23 can be attached on the ground of a factory or a construction site, the workability of construction is improved.

  FIG. 8 is a plan view showing a modification of the above embodiment. In this modified example, the second rib direction shear reinforcing bar 27 and the second rib direction secondary shear reinforcing bar 28 are provided in the same direction as the rib bar 19 and the sub rib bar 20 of the second beam 13b. And different. The second rib direction shear reinforcement bar 27 and the second rib direction secondary shear reinforcement bar 28 are parallel to the plane defined by the rib bar 19 of the second beam 13b so as to include a portion extending in the vertical direction, in the X direction. Are arranged inside the band reinforcement 16 extending outside and outside the beam main reinforcement 18 and mainly prevent the second beam 13b from slipping.

  Although the description of the specific embodiment is finished as described above, the present invention is not limited to the above embodiment and can be widely modified. For example, a column beam joint in which only the first beam in the X direction extends without the second beam, or a column beam junction in which the second beam extends only to one side in the Y direction and the beams intersect in a letter shape in plan view. The present invention can also be applied to the section. One or both of the rib-direction shear reinforcement bar and the rib-direction secondary shear reinforcement bar may be arranged in the joint portion in a direction parallel to the plane defined by the rib bars of the second beam. One or both of the columns and beams may be prestressed concrete.

11: beam-to-column connection structure 12: column 13: beam (13a: first beam, 13b: second beam)
14: Joint 15: Column main bar 18: Beam main bar (18a: Beam main bar of the first beam, 18b: Beam main bar of the second beam)
21: mechanical joint 22: loose shear reinforcement 25a: first beam member

Claims (6)

A beam-to-column connection structure including a mechanical joint in a beam-to-column joint for connecting beam main bars of a beam extending in a predetermined direction,
The beam main bars are arranged in at least two upper and lower stages,
The shear reinforcing bar for reinforcing the beam-column joint is a rib shear reinforcing bar that is disposed between the column main bars arranged on the outermost side in the predetermined direction in the column and has a portion extending in the vertical direction. Column beam connection structure characterized by including.   The column beam connection structure according to claim 1, wherein the beam is made of precast concrete.   The shear reinforcing bar further includes a band direction shear reinforcing bar arranged between the beam main bars arranged above and below and arranged in parallel to a plane perpendicular to the extending direction of the column main bars. The column beam connection structure according to claim 1 or 2. A step of standing a pillar;
Two first beam members made of precast concrete including beam main bars arranged in at least two upper and lower stages are linearly formed on both sides of the column, and one end side of each is positioned at a joint portion with the column. Step to arrange and
Connecting the beam main bars of the two first beam members to each other by a mechanical joint disposed above the column;
Installing a shear reinforcement for the joint;
Placing concrete in the joint, and
The step of installing the shear reinforcing bar includes a beam-direction shear reinforcing bar or a mechanical type which has a portion extending in the vertical direction and is to be extended in a direction parallel to a plane perpendicular to the beam main bar. A method for constructing a beam-to-column connection structure, comprising a step of assembling at a position where the joint should abut or be close to the joint.   5. The method for constructing a column-beam joint structure according to claim 4, wherein the step of assembling the loose shear reinforcement is performed before the step of arranging the first beam member. A step of placing a second beam member arranged in a direction intersecting the first beam member with respect to the column; and the step of arranging the second beam member comprises the step of arranging the first beam member. Done before,
The beam main bar of the second beam member at the joint is a through bar,
6. The beam-column joining structure according to claim 5, wherein the step of assembling the loose shear reinforcement is performed on the second beam member prior to the step of arranging the second beam member. Construction method.

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