JPH11100900A - Joint part structure between reinforced concrete column and steel beam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate designed finishing on the outer column face side of a joint part between a reinforced concrete column and steel beams surrounded by a cover plate. SOLUTION: In an intersecting joint part of a reinforced concrete column 1 and steel beams 2, a column side face to which the steel beams 2 are jointed is covered with a cover plate 11. The upper and lower faces of the steel cover plate 11 is reinforced by through-diaphragms 12. The end faces of the steel beams 2 are rigidly jointed into the specified positions of the end faces of the steel cover plate 11 and through-diaphragms 12, while concrete panel shear reinforcing bars are arranged in the column 1 on the face side without the steel cover plate 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint structure between a reinforced concrete column and a steel beam, and more particularly to a joint structure between a reinforced concrete column and a steel beam in which the shear strength of the beam-column joint is improved.

[0002]

2. Description of the Related Art In recent years, reinforced concrete columns (hereinafter referred to as RC columns) and steel beams (hereinafter referred to as S beams) have been developed in order to reduce the weight of structural bodies, to make structural members slim, and to save labor when assembling frames. ) Has been proposed. The mixed structure by this combination has the advantage that the horizontal rigidity of the frame can be increased and the column span can be increased.

[0003] A beam-column joint for joining an RC column and an S beam is:
It is the part that joins the material ends where the maximum stress occurs when receiving horizontal force or the like during an earthquake. Therefore, a large shearing force acts on a portion (joint panel) surrounded by the RC column and the S beam. If the joint panel yields or breaks due to the shearing force, large deformation occurs in the column-beam joint, and the rigidity and proof strength of the entire frame are insufficient, resulting in sudden brittle fracture. Such a destructive mode is prevented, and finally S
The shear strength and rigidity are required at the beam-column joints so that the beam is caused to bend.

FIG. 5 shows an example of a joint unit having a column-beam joint structure already proposed by the applicant (see Japanese Patent Application Laid-Open No. 7-207755). This joint unit 5
Numeral 0 is manufactured at the factory as a whole, and the cross joint of the S beam has a box shape. This box-shaped cross joint (hereinafter referred to as a box joint) is a steel plate having a height equal to the web height of the S beam 52 and a width equal to the column width of the RC column 51. It consists of a cover plate 53 welded and joined in a rectangular tube shape having the same dimensions.

[0005] The end face 52b of the web of the S beam 52 is welded to the outside surface of the covering plate 53 having a rectangular tube shape (normally, the center position in the width direction of each covering plate 53) by fillet welding. FIG. 5 shows an example in which the S beam 52 is cross-joined to the outer pillar portion in a T-shape as an example.

Further, through-diaphragms 54 of the same upper and lower shape are welded to the upper and lower surfaces of the cover plate 53, respectively. The diaphragm 54 has a substantially cross shape in a plan view, and has a circular concrete casting opening 55 in the center as shown in FIG.
Are formed. Furthermore, the column main bar 56
Has been arranged. Diaphragm tip 54a is S beam 52
Are joined by butt welding to the flange end surface 52a of the boss.

At this time, the column main reinforcement 56 is composed of the same arrangement as that of the conventional column-beam joint, and is arranged with a predetermined covering from the inner surface of the covering plate 53. In anticipation of the concrete restraining effect of the covering plate 53, the band around the column main bar 56 is omitted. Then, after assembling the stirrups (not shown) above the joint unit 50, the formwork is assembled into a columnar shape having a predetermined cross section so as to surround the intersection of the S beam 52, and concrete is poured into the formwork. Thus, the beam-column joint as shown in FIG. 7 is completed.

[0008]

By the way, in the beam-column joint structure shown in FIG. 5, even when concrete of the joint is cast as shown in FIG. Is exposed. Since the design finish of the part is restricted, various problems occur in the outer wall construction. There is also a similar problem in corner posts.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, and to prevent the steel plate as a covering plate from being exposed on the outer surface of the column at the beam-to-column joint of the outer column, so that the outer surface can be easily finished It is an object of the present invention to provide a joint structure between a reinforced concrete column and a steel beam, which can be performed in a short time.

[0010]

In order to achieve this object, according to the present invention, of the portions where a reinforced concrete column and a steel beam are cross-joined, the side of the column to which the steel beam is joined is a steel cover plate. While being covered, the upper and lower sides of the steel cover plate are stiffened by a through-diaphragm, so that the end surface of the steel beam is rigidly joined to a predetermined position of the end surface of the steel cover plate and the through-diaphragm. A concrete panel shear reinforcing member is buried in a pillar having no cover plate.

At this time, it is preferable that the concrete panel shear reinforcing member is a band reinforcing bar surrounding at least the column main bar on the side where the steel covering plate is not provided.

Further, the concrete panel shear reinforcing member is constituted by at least a band reinforcing bar surrounding the column main bar on the side where the steel cover plate is not provided, and a shear reinforcing plate connecting the upper and lower diaphragms. Is preferred.

It is preferable that the concrete panel shear reinforcing member is a strip-shaped steel plate surrounding at least a column main bar on a surface side where the steel cover plate is not provided.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the joint structure between a reinforced concrete column (RC column) and a steel beam (S beam) according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a perspective view showing an outline of a beam-column joint structure of the present invention.
This column-beam joint structure 10 is different from the conventional □ -shaped covering plate 53 shown in FIG. 5 in that the covering plate 11 has a substantially U-shape in plan view as shown in FIGS. It was processed into. In the present embodiment, the covering plate 11 has a thickness of 9 mm.
Although a steel plate of mm is used, it is preferable to appropriately adopt a steel plate having a predetermined thickness according to the magnitude of the designed shearing force at the beam-column joint. For example, it is preferable to use a steel plate having a thickness of about 9 to 19 mm. The substantially U-shaped cover plate 11 includes a central side 11b and a side 11a.
It extends to a position that closes the end face of the S beam 2 joined to the C pillar 1 from the side.

The S beam 2 is butt-welded also to the center of the width of the center side 11b. A substantially cross-shaped diaphragm 12 is welded to the upper and lower surfaces of the cover plate 11. A portion of the distal end of the through-diaphragm 12 where the S beam 2 is not joined is located inside the outer contour of the RC column 1 with a predetermined covering secured. The through-diaphragm 12 has arc-shaped cutouts at positions corresponding to the four corners of the RC column 1, and the column main reinforcement 6 is arranged at the cutout positions at the four corners.

For this reason, the shearing force from the S beam 2 is transmitted to the column via the cover plate 11, but it is preferable to surely obtain the concrete panel restraining effect on the surface where the cover plate 11 is not provided. In the present embodiment, a predetermined number of steps of the reinforcing reinforcing bars 13 for restraining the concrete panel of the joint portion are arranged on the surface where the covering plate 11 is not provided. As shown in FIG.
Of the column main reinforcements 6 arranged at the four corners, the column main reinforcements 6a on the side without the cover plate 11 are surrounded, and are processed into a substantially U-shape so that the ends 13a reach the column main reinforcements 6b on the side with the cover plate 11 on. I have. The end portion 13a is processed and fixed in a hook shape having a predetermined angle (for example, 135 °) with respect to the column main reinforcement 6b. In the present embodiment, five-stage shear reinforcing bars 13 are arranged at positions corresponding to the webs of the S beam 2. It is preferable to design the number of reinforcing bars and the diameter of the reinforcing reinforcing bar 13 in accordance with the thickness of the covering plate on the other surface. Also,
As the standard of the reinforcing bar to be used, a high-strength reinforcing bar of 785 MPa class or an ultra-high-strength reinforcing bar of 1275 MPa class is preferable. It should be noted that the shear reinforcing bar 13 may be a closed band bar that surrounds all the column main bars 6 in a square shape.

FIG. 2B is a plan view showing a beam-column joint structure showing an example of a corner post. As shown in FIG.
An L-shaped cover plate 11c as viewed in plan is provided so as to cover the side surface of the RC column 1 sandwiched between S beams 2 joined orthogonally to the column 1. Then, in the same manner as shown in FIG. 2 (a), the shear reinforcing steel 13 surrounds the column main reinforcing bars 6a, 6b.
Has been arranged.

FIG. 3 shows an embodiment in which a shear reinforcing steel plate 15 is added in order to increase the shear strength of the surface without the cover plate 11. In order to make the configuration of the shear reinforcing steel plate 15 easy to understand, the illustration of the shear reinforcing steel bars 13 is omitted in a partial range. Shear reinforced steel plate 15
As shown in FIG. 1, the butt welding is performed on the diaphragm 12 so as to connect the portions sandwiched between the distal ends of the through diaphragms 12 located above and below the covering plate 11. The thickness of the shear reinforcing steel plate 15 is preferably set to be the same as the thickness of the diaphragm in consideration of the rigidity ratio with the diaphragm. The use of the reinforcing steel plate 15 improves the balance of the beam-column joint 10 as a shear resistance element.

FIG. 4 shows the shear reinforcing steel 13 shown in FIG.
In this embodiment, a strip-shaped steel plate 16 is used in place of the embodiment. The thickness and width of the strip-shaped steel plate may be set so that strength equivalent to that of the case of the shear reinforcing steel 13 is obtained. The material of the strip-shaped steel plate is SS400, which is processed in the same shape as the shear reinforcing bar 13 in a plan view, and is bent in a substantially U-shape so as to surround the column main bar 6a. The tip extends to the position of the column main bar 6b surrounded by the cover plate 11, and is fixed so as to surround the column main bar 6b. At this time, the strip steel plate 1
Reference numeral 6 is arranged so as to secure a predetermined covering from the end face of the concrete column. When concrete is poured into the beam-column joint, in order to integrate it with the concrete, it is also possible to use a striped steel plate, attach a cotter with fine irregularities on the plate surface, or provide a predetermined amount of punching holes. preferable. As described above, the concrete panel at the beam-column joint can be sufficiently restrained by the shear reinforcement or the like even on the surface where the covering plate 11 shown in FIGS. The shear strength of the entire joint can be reliably maintained.

At the beam-column joint, besides the shear strength,
Although the bearing capacity acting on the column concrete of the flange of the S beam 2 must be taken into consideration, in the present invention, the bearing force from the flange of the S beam 2 is increased through the through diaphragm 12 having a large thickness and a large transmission area. It is transmitted to the column concrete, and the concrete can exhibit sufficient bearing capacity. Further, an opening for placing concrete is formed in the through-diaphragm 12, and the shape, size, position and the like can be freely set as long as the inside concrete can be filled without any trouble. The same applies to the shape of the notch for penetrating the column main muscle.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of a joint structure between a reinforced concrete column and a steel beam according to the present invention.

FIG. 2 is a plan view showing an example of a joint structure between a reinforced concrete column and a steel beam shown in FIG. 1 and an example of a joint structure at a corner post.

FIG. 3 is a perspective view showing another embodiment of the joint structure between the reinforced concrete column and the steel beam.

FIG. 4 is a perspective view showing another embodiment of the joint structure between the reinforced concrete column and the steel beam.

FIG. 5 is a perspective view showing an example of a conventional joint structure between a reinforced concrete column and a steel beam.

FIG. 6 is a plan view showing a joint structure between the reinforced concrete column and the steel beam shown in FIG. 5;

FIG. 7 is a perspective view showing the appearance of the joint structure between the reinforced concrete column and the steel beam shown in FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 RC column 2 S beam 6 Column main bar 10 Column beam joint structure 11 Cover plate 12 Through diaphragm 13 Shear reinforcing steel 15 Shear reinforcing steel plate 16 Strip steel plate

Claims (4)

[Claims] In a cross section of a reinforced concrete column and a steel beam, a side surface of the column to which the steel beam is connected is covered with a steel covering plate, and upper and lower sides of the steel covering plate are passed through by a diaphragm. The steel cover plate and the end face of the steel beam are rigidly joined to predetermined positions of the end surfaces of the through-diaphragm and the steel cover plate, and concrete panels are sheared and strengthened in the columns having no steel cover plate. A joint structure between a reinforced concrete column and a steel beam, wherein the member is buried. 2. The joint between a reinforced concrete column and a steel beam according to claim 1, wherein the concrete panel shear reinforcing member is a band reinforcing bar surrounding at least a column main bar on a surface side where the steel covering plate is not provided. Part structure. 3. The concrete panel shear reinforcing member comprises a band reinforcing bar surrounding at least the column main bar on the side where the steel cover plate is not provided, and a shear reinforcing plate for connecting between the upper and lower diaphragms. The joint structure between a reinforced concrete column and a steel beam according to claim 1. 4. The joint between a reinforced concrete column and a steel beam according to claim 1, wherein the concrete panel shear reinforcing member is a strip-shaped steel plate surrounding at least the column main bar on the side where the steel covering plate is not provided. Part structure.