JP5634627B1 - Mixed structural frames of reinforced concrete columns and steel beams - Google Patents

Abstract

[PROBLEMS] A mixed structure frame of RC columns and S beams that can reasonably realize a long-span structure. Columns can be arranged freely and concrete can be placed easily at the joint between the columns and beams. Provide a mixed structural frame of reinforced concrete columns and S-beams. An S-beam is stopped at a face position on a column side surface, and a bearing plate is disposed at an end thereof. A wide connection plate is attached to the flange end of the S beam, and the connection plates on both sides of the column are joined together by welding using joint reinforcing bars to fix and fix against bending stress. In addition, a PBL dowel having a large number of holes fixed to the bearing plate is arranged in the vertical direction in the column / beam joint so that the shearing force of the beam is transmitted to the column / beam joint. [Selection] Figure 2

Description

  The present invention relates to a mixed structure frame in which a column is a reinforced concrete structure (hereinafter “RC structure”) and a beam is a steel structure (hereinafter “S structure”).

  In structures such as buildings and workpieces that require a relatively large span, the weight of the beam does not increase, there is no risk of creep bending of the beam due to long-term use, and the overall building is higher than the S frame As a structural framework that can secure rigidity and can be constructed in a shorter construction period than an RC frame, a mixed structural frame type in which a column is an RC structure and a beam is an S structure is known.

  In this framework type, the most important issue is how to rigidly connect and integrate the RC column and the S beam, and the construction method and structural details of the column / beam junction are problems.

  As a specific solution, in order to fix the end of the S beam in the column, a steel pipe is built in the RC column, and the built-in steel tube and the end of the S beam are welded and integrated. Adopting the method and making the steel pipe column built into it a round steel pipe (Cited documents 1, 2), a square steel pipe (Cited documents 3, 4), a H-shaped steel (Cited documents 5, 6), etc. There is.

  In addition, the end of the beam in one direction is made of RC, and the method of piercing the S beam in the orthogonal direction (Cited document 7) is adopted. (Patent Documents 6 and 8).

  Paying attention to the flange of the S beam, the beam flange is stopped by the S column built in the column (Cited documents 1 and 3) and the steel of the beam flange penetrates the column / beam joint continuously. (Citations 2, 4, 5, 6, 7, and 8) exist.

JP-A-5-272170 Japanese Patent Laid-Open No. 10-231559 JP-A-8-270071 JP-A-11-36449 JP 2000-160686 A JP 2000-160687 A Japanese Patent Laid-Open No. 10-280541 Japanese Patent Laid-Open No. 8-135018

  The RC structural frame and S structural frame are structural structures suitable for buildings with relatively large spans, but the mixed structural frames that have been put to practical use so far are the pillars. -There are some major issues concerning beam joints as shown below.

First, the first problem is a problem in the structure and shape of the column / beam joint.
FIG. 13 is a diagram showing the configuration of a conventional column / beam joint of a RC-frame and S-beam mixed structure. (1) is a horizontal sectional view of the upper flange level near the column-beam joint, (2 ) Is a vertical sectional view near the column-beam joint. Reference numeral 1 is an RC column, 3 is an S-shaped beam, 11 is a column main reinforcement, 12 is a column shear reinforcement (Hoop reinforcement), 15 is a reinforcement plate surrounding the column / beam joint, and 24 is a floor slab. Show.
In the conventional column / beam joint 16 having a mixed structure of the RC column 1 and the S-shaped beam 3, the S-shaped beam 3 penetrates the column / beam-connected portion 16 or is stopped by the built-in S column. In any type, since the flange 31 of the steel beam is inserted into the column beyond the position where the column reinforcement is arranged, as shown in FIG. 13, the position where the column reinforcement 11 can be arranged is the corner of the column. It is limited only to the corners, and the number of column bars 11 that can be arranged is limited. In consideration of the actual column dimensions and the flange width of the beam, in most cases, the number of column reinforcements is three at the corners of the column, and the total is twelve. As a result, it is difficult to sufficiently secure the bending strength of the column, and there is a problem that the column size must be increased in order to increase the bending strength of the column.

The second point of the problem is a problem in mechanical performance related to the stress transmission mechanism from the beam to the column.
The stress borne by the S-shaped beam must be transmitted to the RC column in the column / beam joint, but bending stress is applied to the column from the H-shaped steel beam member through the concrete block at the column / beam joint. To transmit, a very complex stress transmission mechanism must be envisaged and the mechanism is unclear. In addition, since the bond stress at the interface between the steel beam surface and the concrete is small, it is not easy to transmit shearing force, and the indirect attempt to prevent the shear failure of the entire joint by surrounding the column / beam joint with a steel plate. Specific measures are adopted, and it does not have a clear stress transmission mechanism that directly transmits shear force.
If the column-beam joint of a conventional mixed structure frame is simply expressed, if an S-shaped beam (H-shaped steel) is thrust into the concrete of the RC column and the surroundings are constrained, both the steel frame and the concrete are managed. The idea is that it should transmit force and transmit both bending and shearing forces. As described above, the transmission mechanism of bending stress and shearing force in the column / beam joint of the conventional mixed structure is vague and unclear, and it is actually difficult to explain it assuming a complicated stress transmission mechanism. It is.

The third problem is the problem of construction reliability.
The column / beam joint is the most important part of any structural frame, but in particular, this structural form that connects different structural members, RC and S, governs the safety and reliability of the entire structural frame. Has importance.
In the conventional mixed structure frame, as shown in FIG. 13, two S-shaped beams 3 are inserted into the column / beam joint 16 in a cross shape. As a construction procedure, after the reinforcement of the column reinforcement 11 and the beam steel frame member 3 are arranged, the concrete of the column / beam junction is placed from above. However, since the flange 31 of the S-shaped beam 3 has a relatively large width, usually about 300 mm, it is extremely difficult to completely fill the concrete directly under the flange 31. In particular, the web plate 34 of the S-shaped beam 3 is present immediately below the center of the flange 31 and hinders the horizontal movement of the concrete. Usually, the S-shaped beam 3 in two directions is arranged in a cross shape, and the web plate 34 is orthogonal and connected at the intersection, so the concrete cannot flow in any direction, and the most important column center In some cases, the concrete is not sufficiently filled in the position directly below the flange 31 above the part position, and a gap is generated.

  This problem has been confirmed by mock-up experiments on full-size column / beam joints. Even if the concrete is carefully laid after fully recognizing this problem, there are cases where the concrete is not sufficiently filled, and it can be said that this problem cannot be solved easily.

The present invention has been made in order to solve the above-mentioned problems. 1) It is possible to secure a degree of freedom in design capable of sufficiently securing a desired bending strength without being restricted by the bar arrangement in the RC column. ) Stress transmission from S beam to RC beam column, especially stress transmission mechanism in the column / beam joint is clear and reliable 3) Filling concrete at the most important column / beam joint as structural frame "RC column + S beam mixed structure frame" that can be reliably performed and that high-reliability construction is possible, and that is excellent in design performance, workability, reliability, and economy that solve these problems It is an object of the present invention to realize and provide the above.

The following configuration is means for solving the above-described problems and achieving the object.
<Configuration 1>
The structure is a reinforced concrete structure (hereinafter referred to as “RC structure”), and at least one of the two horizontal horizontal beams is a steel structure (hereinafter referred to as “S structure”). The framework,
The S-shaped beam is extended to the boundary surface between the columns (hereinafter referred to as “column face surface”), and an end of the S-shaped beam is provided with a bearing plate in contact with the column face surface. The S-shaped beam is arranged in close contact with only the outside of the opposite side surfaces,
An upper flange connection plate is disposed above the upper flange of the S-shaped beam end, and a lower flange connection plate is disposed below the lower flange;
The upper joint bars are arranged in parallel with a predetermined reinforcing bar interval on the upper side of the upper flange connection plate on both sides of the RC pillar, and both ends thereof are welded to the upper flange connection plate,
A lower end joint reinforcing bar is arranged in parallel with a predetermined reinforcing bar interval on the lower side of the lower flange connection plate on both sides of the RC pillar, and its end is welded to the lower flange connection plate,
One or more vertical plates with holes (hereinafter referred to as “PBL gibber”) are arranged inside the column / beam joint of the bearing plate arranged at the end of the S-shaped beam. Mixed structural framework.

<Configuration 2>
It is a mixed structural framework in which the column is an RC column, the large beam in at least one of the two horizontal directions is an S column, and the S column is present on both sides of the RC column.
The S-shaped beam is extended to the column face, and an end of the S-shaped beam is provided with a bearing plate in contact with the column face, and the S-shaped beam is provided only on the outer sides of the opposite sides of the RC column. Are arranged closely,
An upper flange connection plate is disposed above the upper flange of the S-shaped beam end, and a lower flange connection plate is disposed below the lower flange;
Reinforcing bar fixing couplers or long nuts (hereinafter referred to as “fixing couplers”) in parallel with a predetermined distance above the upper flange connection plate and below the lower flange connection plate on both sides of the RC pillar. ) Is welded,
The upper and lower end joining rebars are inserted into the fixing couplers on both sides of the RC column and fixed and integrated by grout filling.
A mixed structural frame, wherein one or more PBL dowels are arranged inside a column / beam joint of the bearing plate arranged at the end of the S-shaped beam.

<Configuration 3>
It is a mixed structural framework in which the column is an RC column, the large beam in at least one of the two horizontal directions is an S column, and the S column is present on both sides of the RC column.
The S-shaped beam is extended to the column face, and an end of the S-shaped beam is provided with a bearing plate in contact with the column face, and the S-shaped beam is provided only on the outer sides of the opposite sides of the RC column. Are arranged closely,
An upper flange connection plate is disposed above the upper flange of the S-shaped beam end, and a lower flange connection plate is disposed below the lower flange;
Reinforcing bar fixing through holes are provided at predetermined intervals in the bearing plates on both sides of the RC pillar,
Inserting and penetrating the upper and lower joints into the through-holes of the bearing plate on both sides of the RC column, and fixing and integrating the outer or inner and outer sides of the bearing plate with nuts.
A mixed structural frame, wherein one or more PBL dowels are arranged inside a column / beam joint of the bearing plate arranged at the end of the S-shaped beam.

<Configuration 4>
It is a mixed structural framework in which the column is an RC column, the large beam in at least one of the two horizontal directions is an S column, and the S column is only on one side of the RC column.
The S-shaped beam is extended to the column face, and an end of the S-shaped beam is provided with a bearing plate in contact with the column face, and the S-shaped beam is closely attached only to the outside of the RC column. And the configuration
An upper flange connection plate is disposed above the upper flange of the S-shaped beam end, and a lower flange connection plate is disposed below the lower flange;
An upper end joint rebar is disposed above the upper flange connection plate, and a lower end joint rebar is disposed below the lower flange connection plate with a predetermined rebar spacing. Is fixed and integrated in one of the following structures: welding, fixing with a coupler, and fixing nuts to the bearing plate.
One or more PBL dowels are arranged inside the column / beam joint of the bearing plate arranged at the end of the S-shaped beam,
U-type fixing in which the end opposite to the end fixed to the S-shaped beam of the upper end joining rebar and the lower end joining rebar is mechanical fixing, bending fixing, and both are bent and integrated, A mixed structure frame characterized by adopting a fixing structure of any of those mixing methods.

<Configuration 5>
In the mixed structural framework according to any one of Configurations 1 to 4,
The mixed structural frame is characterized in that the ends of the upper and lower flanges of the S-shaped beam are widened and configured in advance as a wide connecting plate.

<Configuration 6>
It is a mixed structural framework in which the column is an RC column, the large beam in at least one of the two horizontal directions is an S column, and the S column is present on both sides of the RC column.
The S-shaped beam is extended to the column face surface in both directions, and a bearing plate that is in contact with the column face surface is provided at the end of the S-shaped beam, and only on the outer sides of the opposite sides of the RC column. S construction large beams are arranged in close contact,
The unidirectional S-shaped beams on both sides of the RC column are joined and integrated with the flange or flange connection plate of the S-shaped beam by welding the upper joint and the lower joint.
The S-shaped beam in the other direction is fixed and integrated with the bearing plate using the nuts at the upper end joining rebar and the lower end joining rebar,
A mixed structural frame, wherein one or more PBL dowels are arranged inside a column / beam joint of each bearing plate arranged at the end of the S-shaped beam.

<Configuration 7>
In the mixed structural framework according to any one of Configurations 1 to 6,
A mixed structural frame characterized in that the web plate of the S-shaped beam is extended to the inside of the column / beam joint inside the bearing plate and also used as the PBL gibber.

<Configuration 8>
In the mixed structural framework according to any one of Configurations 1 to 6,
The S-shaped beam on the outside of the RC column extends into the column / beam joint inside the bearing column, and is joined / integrated to the bearing plate and the S beam on the opposite side of the RC column. A mixed structural frame characterized in that the entire cross-section or a part of the flange of the S-shaped large beam located in the column / beam joint is cut off.

<Configuration 9>
In the mixed structural framework according to any one of Configurations 1 to 8,
Mixing characterized in that horizontal and vertical reinforcing ribs for suppressing out-of-plane deformation of the bearing plate are arranged at the end of the S-shaped beam located outside the column / beam joint of the bearing plate. Structural framework.

<Configuration 10>
In the mixed structural framework according to any one of Configurations 1 to 9,
A through hole or a U-shaped slit slightly larger than the diameters of the upper end joining rebar and the lower end joining rebar is provided at a position where the upper end joining rebar and the lower end joining rebar of the bearing plate pass. Mixed structure framework to do.

<Configuration 11>
In the mixed structural framework according to any one of Configurations 1 to 10,
The bottom of the bearing plate is placed in the RC depending on whether the bearing plate is embedded inside the column / beam joint from the column face or the column width at the bottom of the bearing plate is widened. A mixed structural framework, characterized by being supported by concrete pillars.

<Configuration 12>
In the mixed structural framework according to any one of Configurations 1 to 11,
Horizontal rebars are passed through holes provided in the PBL dowels, and some of the through rebars also serve as horizontal shear reinforcement bars that surround the outer periphery of the column / beam joint. Mixed structure frame characterized by.

<Configuration 13>
In the mixed structural framework according to any one of Configurations 1 to 12,
A mixed structural frame, wherein stud bolts are arranged on either or both of the inner side of the column / beam joint of the bearing plate and the web surface extending into the column / beam joint.

<Configuration 14>
In the mixed structural framework according to any one of Configurations 1 to 13,
A mixed structural framework characterized in that the design standard strength of the concrete constituting the column / beam joint is higher than that of the concrete in other parts.

<Configuration 15>
In the mixed structural framework according to any one of Configurations 1 to 14,
A mixed structural frame characterized in that concrete having a low drying shrinkage rate or expansive concrete is adopted as the concrete constituting the column / beam joint.

<Effects of solving Problem 1>
In the present invention, first, a structure in which the S-shaped large beam is not inserted into the column / beam joint is basic. The S-shaped beam is stopped by a bearing plate provided at the column face position on the outer periphery of the column, and the S-shaped beam does not enter the column. In order to transmit the shearing force of the beam, a configuration in which a part of the web plate is inserted into the column (Configuration 7 and Configuration 8) is adopted. The web plate is the center, and the flange plate of the beam is cut to a minimum width. Therefore, the beam flange does not hinder the arrangement of the column reinforcement, and the desired column reinforcement can be freely arranged in the column cross section. Therefore, as in the case of a normal pure RC frame, a great effect on the structural performance and structural design that the bending strength of the column can be freely set is realized.

  This also means that the bending strength and axial strength of the column can be set effectively, and the column cross section can be designed economically. Furthermore, since the member cross section of the S-shaped beam can be set regardless of the arrangement of the column bars, the member cross-section of the S-shaped beam can be set freely, and the economic design of the beam member can also be performed, which contributes to the economic efficiency of the frame design. The structure is extremely excellent from the viewpoint.

<Effect of solving Problem 2>
Also from the viewpoint of the stress transmission mechanism from the S beam to the RC column, which is the second point of the problem, an extremely clear stress transmission mechanism is realized in the present invention. In other words, the bending strength of the S-shaped beam is replaced by a jointed rebar that has a tensile strength greater than the tensile yield strength of the flange at the end of the beam, and the inside of the column / beam joint is a column / beam joint of a pure RC frame. It has become. Therefore, it is not necessary to construct and assume a complicated stress transmission mechanism from a steel member to concrete, such as concrete compression struts and torsional stress transmission, as in the conventional mixed structure.

  As a mechanism for transmitting the compressive stress due to bending of the S-shaped beam, it is possible to transmit even the compressive stress of the joint reinforcing bar integrated with the beam flange. However, in the present invention, a bearing plate is provided at the beam end at the column face position. This bearing plate transmits the compressive stress of the beam flange as the bearing stress on the column / beam joint surface.

  As described above, the bending stress at the end of the S-shaped beam is transmitted and fixed in the column / beam joint by the jointed reinforcing bar connected to the beam flange. It is more reliable than the anchorage of RC main beam. That is, in a normal RC frame, due to the positive and negative target moments during an earthquake, the beam main bars on both sides of the column are subjected to tensile stress on one side and compressive stress on the other side, and are fixed in the column / beam joint. However, if the anchorage is not sufficient at this time, the main beam of the beam will slip and come out, and the stress during the earthquake cannot be borne. Is damaged.

  On the other hand, in the present invention, since the bearing plate integrated with the S-shaped beam and the joining reinforcing bar exists at the column face positions on both sides of the fixing joining reinforcing bar, the joining reinforcement is caused by the bearing resistance of the bearing plate. Is completely fixed and fixed on the compressive stress side, and the joint rebar is immovable. Furthermore, the stress state of the joint rebar is also in a state where there is almost no compression side stress in the joint rebar in the joint because the compression side stress is transmitted to the concrete at the column / beam joint by the bearing plate. What is necessary is just to transmit the tensile stress from the opposite face position of a column to the concrete in a column-beam junction part by the adhesion stress of a joining reinforcement. Therefore, even if only the fixing performance based on the adhesion stress of the joining reinforcing bar is evaluated, the safety / reliability is twice as high as that of a normal RC frame. In addition, the fixing performance by the compression side support plate has a reliability far exceeding this. In extreme terms, in the column / beam joint of the present invention, anchoring by the joint rebar is ensured even if there is no adhesion stress between the joint rebar and concrete, and an extremely safe and reliable joint is realized. ing.

  Next, the transmission mechanism for the shearing force of the beam will be described. In the present invention, a PBL dowel is used to transmit the shearing force of the beam. A PBL dowel is a steel plate with a plurality of holes with a diameter of about 30 mmφ to 50 mmφ, which is embedded in concrete. The concrete has a two-sided shear resistance mechanism that penetrates into the hole, and has a very high rigidity and a large shear force. Can be transmitted.

  In the present invention, usually two or more perforated steel plates (PBL gibbles) are vertically arranged on the column / beam joint side of the bearing plate provided at the end of the S-shaped beam. As a result, the shear force of the beam can be reliably transmitted to the concrete of the column / beam joint without obstructing the concrete placement in the column / beam joint without causing shear deformation. it can.

  Furthermore, in the present invention, a strip line (Hoop line) surrounding the column / beam joint is passed through the hole of the PBL dowel. By inserting a reinforcing bar into the hole of the PBL dowel, it is possible to increase the toughness (deformation performance) as a shear force transmission mechanism of the PBL dowel, and at the same time, constrain the periphery of the column / beam joint with a hop bar. Ensures safety and stability against shear failure at beam joints.

<Effects of solving Problem 3>
In the present invention, the penetration of the S-shaped large beam into the column / beam joint is eliminated, and the problem of difficulty in filling the concrete directly under the S-shaped large beam flange is eliminated. Since only the reinforcing bars, the steel plates of the PBL gibber arranged in the vertical direction, and the surrounding hop bars exist in the column / beam joint, it is the same as a normal RC column / beam joint. There is no difficulty in installation. In addition, the joint reinforcement in the column / beam joint is a straight joint that connects the S-shaped beams on both sides of the column, and there is no anchoring bending rebar in normal RC construction. The streaks are refreshed and concrete placement and filling is much easier than normal RC construction.
By this effect, the concrete construction of the most important column / beam joint as a structural framework can be easily performed, high quality can be ensured, and a highly reliable structural framework can be constructed. This good workability also leads to the economics of construction work.

As mentioned above, although the effect by the solution of this invention with respect to each subject was demonstrated, it is as follows when the effect of this invention is summarized.
(1) The column reinforcement can be arranged with respect to the full width of the RC column, and the bending strength of the column can be increased.
(2) The stress transmission mechanism from the S beam to the RC column is clear and highly reliable.
(3) It is easy to place concrete at the column / beam joint, ensuring high quality in construction.
(4) High structural performance, high quality and high efficiency construction can be performed, so that a structural framework with excellent workability and economy can be realized.
Furthermore, when the structural framework of the present invention is employed, there is an effect that a building structure having the following advantages can be realized.
(5) An efficient building space having a large effective dimension under the beam can be economically configured for a building having a large vertical load load in which stress due to the vertical load is dominant and a large span.
(6) When the frame structure of the present invention is applied to a building that requires a large span, it can secure higher rigidity than a steel frame and does not become a heavy building like an RC frame. An excellent building can be realized from both viewpoints.

BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing which shows the whole structure of the mixed structure frame of this invention, (1) The top view (bottom view) which shows the positional relationship of RC column and S beam of a mixed structure frame, (2) RC column and S frame It is a vertical sectional view which shows the whole shape of the mixed structure frame by a beam. FIG. 2 is a detailed view showing the structure of the column / beam joint of the present invention, in which the joint reinforcing bars are integrated with the S-shaped beam by welding. (1) Horizontal sectional view of the upper flange level near the column / beam joint (see) (Lower figure), (2) Vertical sectional view near the column / beam joint, (3) Horizontal sectional view (bottom view) at the lower flange level near the column / beam joint. FIG. 5 is a detailed view showing the structure of the column / beam joint of the present invention, in which the joint reinforcing bars are integrated with the S-shaped beam by a mechanical coupler. (1) Horizontal sectional view of the upper flange level near the column / beam joint (Bottom view), (2) Vertical sectional view near the column / beam joint, (3) Horizontal sectional view (bottom view) at the lower flange level near the column / beam joint. FIG. 2 is a detailed view showing the structure of the column / beam joint of the present invention, in which the joint reinforcing bars are fixed to the bearing plate by the fixing nut (1) Horizontal sectional view of the upper flange level in the vicinity of the column / beam joint ), (2) Vertical sectional view near the column / beam joint, (3) Horizontal sectional view (bottom view) at the lower flange level near the column / beam joint. It is a detailed view showing the configuration of the column / beam joint of the present invention, and an example in the case where the S-shaped large beam is present only on one side of the column (exemplary case where the joining rebar is integrated with the S-beam by welding) ( 1) Horizontal sectional view (upper view) of the upper flange level near the column / beam joint, (2) Vertical sectional view near the column / beam joint, and (3) Vertical sectional view near the column / beam joint. . FIG. 2 is a detailed view showing the structure of the column / beam joint of the present invention, in which the flange at the end of the S-shaped beam is composed of a pre-expanded built-in H (the joining rebar is integrated with the S-beam by welding) (1) Horizontal sectional view of the upper flange level near the column / beam joint (bottom view), (2) Vertical sectional view near the column / beam joint, (3) Column / beam joint It is a horizontal sectional view (bottom view) of the lower flange level in the vicinity. FIG. 5 is a detailed view around the column / beam joint showing an embodiment of the present invention in the case of S-shaped beams in both the X and Y2 directions. (1) Horizontal sectional view of the upper flange level in the vicinity of the column / beam joint (downward view) ), (2) Vertical sectional view near the column / beam joint. It is detail drawing which shows the structure of the column-beam connection part of this invention, and the Example by which the web of the edge part of S-beam is extended even in the column (when a joining reinforcement is integrated with S-beam by welding) (1) Horizontal cross-sectional view of the upper flange level near the column / beam joint where the S-shaped beam is extended in the column (bottom view), (2) The S-shaped beam is in the column Vertical cross-sectional view in the vicinity of the column / beam joint of the embodiment which is extended and continuous with both beams, (3) The column of the embodiment where the web of the S-shaped beam is extended into the column and is continuous with the both beams・ It is a horizontal sectional view (bottom view) of the lower flange level near the beam joint. It is detail drawing which shows the shape of the bearing plate arrange | positioned at the edge part of S-shaped large beam of this invention, (1) The vertical sectional view which shows the positional relationship of the bearing plate and the RC column of the edge part of S-shaped beam. ) Elevation view showing the shape of the bearing plate of the embodiment in which a U-shaped slit for joining reinforcing bars (upper reinforcing bars) is provided on the upper part of the bearing plate, (3) Both through holes are provided for upper and lower reinforcing bars of the joining reinforcing bars FIG. 4 is an elevation view showing the shape of the pressure plate of the example. Detailed view showing the shape of an embodiment in which the bearing plate at the end of the S-shaped beam of the present invention is supported by the concrete of the RC column (the case where the joining rebar is integrated with the S-shaped beam by welding) (1) Horizontal sectional view of the upper flange level in the vicinity of the column / beam joint (bottom view), (2) Vertical sectional view in the vicinity of the column / beam joint (Example in which the column dimensions at the bottom of the bearing plate are increased by the bearing plate thickness) ), (3) Vertical sectional view near the column / beam joint (an example in which the column dimensions of all floor heights are increased by the bearing plate thickness). Detailed view of an embodiment in which a hop bar is passed through the PBL gibber of the present invention (an example in which a joint bar is integrated with an S-beam by welding) (1) Horizontal section at the upper flange level in the vicinity of a column / beam joint Figure (bottom view), (2) Vertical sectional view near the column-beam joint. Detailed view of an example of using stud bolts for shear force transmission (example of joining rebar integrated with S beam by welding) (1) Horizontal section of upper flange level near column / beam joint (see (Lower figure), (2) Vertical sectional view near the column / beam joint, (3) Horizontal sectional view (bottom view) at the lower flange level near the column / beam joint. Detailed view showing the structure of a conventional RC-column and S-beam mixed column / beam joint (1) Horizontal sectional view of the upper flange level in the vicinity of the column / beam joint (bottom view), (2) Column・ It is a vertical cross section near the beam joint.

  Since the present invention is a mixed structure of RC columns and S beams, it is characterized by the configuration of the column / beam joint that is the contact point between them. Hereinafter, embodiments of the present invention will be described with reference to the drawings illustrating examples.

Example 1 is a mixed structural frame in which a column is reinforced concrete (RC column) and a large beam in at least one of two horizontal directions is a steel frame (S beam). In the case where S-shaped beams are present on both sides of the RC column, the S-shaped beam is extended to the boundary surface (column face surface) between the columns and the end of the S-shaped beam is in contact with the column face surface. Is provided, and the S-shaped beam is closely arranged only on the outer sides of the opposite side surfaces of the reinforced concrete column. An upper flange connection plate is disposed above the upper flange of the S-shaped beam end, and a lower flange connection plate is disposed below the lower flange. Upper end joint rebars are arranged in parallel with a predetermined rebar spacing on the upper side of the upper flange connection plate on both sides of the column, and both ends thereof are welded to the upper flange connection plate. Lower end joint reinforcing bars are arranged in parallel with a predetermined reinforcing bar interval on the lower side of the lower flange connection plate on both sides of the column, and the ends thereof are welded to the lower flange connection plate. One or more vertical plates with holes (PBL dowels) are arranged on the column / beam joint side of the bearing plate arranged at the end of the S-shaped beam.
1 and 2 are diagrams showing a mixed structural frame of reinforced concrete columns and S-shaped beams in Example 1. FIG.
FIG. 1 shows the overall structure of a mixed structure frame according to the present invention and the positional relationship of each component. (1) is a plan view and (2) is a cross-sectional view.
As shown in FIG. 1 (1), there are RC columns 1 on both sides of the S-shaped beam 3. The large beam 2 in the direction orthogonal to the RC column 1 shows a case of RC structure, and S-shaped small beams 23 are arranged at predetermined intervals in parallel therewith. The entire floor slab 24 is supported by the steel beam 3, the orthogonal beam 2 and the beam 23. Reference numeral 16 denotes a column / beam joint where the RC column 1 and the S-shaped beam 3 intersect, and 38 denotes a bolted joint portion of the S-shaped beam 3.

FIG. 2 shows the details of the column / beam joint 16 where the RC column 1 and the S beam 3 cross. 2 (1) is a plan view of the upper flange level of the S-shaped beam, FIG. 2 (2) is a vertical sectional view, and FIG. 2 (3) is a plan view of the lower flange level.
An upper flange connection plate 35 is disposed on the upper flange of the end of the S-shaped beam 3 and a lower flange connection plate 36 is disposed on the lower side of the lower flange. The upper flange connection plate 35 and the lower flange connection plate 36 are integrated with the beam flange 31 by welding, respectively. The connecting plates 35 and 36 on both sides of the column are welded to each other via the upper end joining reinforcing bar 51 and the lower end joining reinforcing bar 52, thereby integrating the S-shaped beam 3 and the RC column 1 on both sides of the column.

  The S-shaped large beam 3 extends to the boundary surface (column face surface) between the columns. A bearing plate 4 is attached to the end of the S-shaped beam 3 and is closely attached to the side surface of the RC column 1. When seismic force is applied to this mixed structural frame, the tensile stress at the end of the S-shaped beam 3 is fixed by the tensile force of the joint reinforcement, and the compressive stress is transmitted to the concrete on the column side by the support pressure of the bearing plate 4. The Since the compression side of the joint rebar is completely fixed by the bearing plate 4, there is almost no compressive stress in the joint reinforcement on the column / beam joint side of the bearing plate 4, and the opposite end of the joint reinforcing bar is not present. Tensile force can be sufficiently fixed by the adhesion of concrete in the column / beam joint. Even if the fixing due to this adhesive force is insufficient for some reason, the movement and withdrawal of the joint rebar are completely restrained by the resistance of the bearing plate 4, so that the end of the S-shaped beam is fixed and fixed. Is safe.

  A steel plate (“PBL gibber”) 43 provided with a large number of holes 44 is arranged in the vertical direction on the column / beam joint side of the bearing plate 4. Normally, two or more PBL dowels 43 are arranged for one bearing plate 4. The PBL dowel 43 is a mechanism for transmitting a shearing force by two-surface shearing of concrete filled in the hole, and the shear strength can be freely set by the hole diameter, the number of holes, the steel plate thickness, and the like. The PBL dowel 43 is characterized in that it can easily ensure a large shear strength and has extremely high rigidity that hardly deforms at that time.

FIG. 3 is a diagram illustrating a mixed structural frame of the RC column and the S-shaped beam in at least one of the two horizontal directions according to the second embodiment.
FIGS. 3A and 3B show examples in which the fixing structure of the joining reinforcing bar is different. FIG. 3A is a plan view of the upper flange level of the S-shaped beam 3, FIG. 3B is a vertical sectional view, and FIG. 3 is a plan view of a lower flange level of 3. FIG.
As shown in FIG. 3, when the S-shaped beam 3 is present on both sides of the RC column 1, the S-shaped beam 3 is extended to the column face surface, and the end of the S beam 3 is formed on the column face surface. The contact pressure plate 4 is provided so that the S-shaped beam 3 is disposed in close contact with only the outer sides of the opposite sides of the RC column 1. Two PBL dowels 43 are disposed on the column / beam joint side of the bearing plate 4 disposed at the end of the S-shaped beam 3.
The ends of the S-shaped beam 3 on both sides of the column 1 are widened flanges 37 having a shape in which the flange width has been widened in advance, and these are joined and integrated by the upper joints 51 and the lower joints 52. In this structure, a mechanical coupler (long nut) 53 for fixing a reinforcing bar is welded and joined in advance to the widening flange 37, and the joining reinforcing bars 51 and 52 are inserted into the coupler, and a predetermined grout material is inserted into the gap between them. It is integrated by injection.
In this figure, the upper flange 37 and the lower flange 37 are widened in advance at the flange width of the end portion of the S-shaped beam 3, but instead of the widened flange 37, the upper and lower flanges of the upper flange are the same as in FIG. The connection plates 35 and 36 may be arranged on the lower side.
This structure is advantageous in that it is not affected by the weather and that field work can be performed relatively quickly as compared to welding in the field.

FIG. 4 shows an embodiment in which the joining rebar is fixed with a nut. FIG. 4 (1) is a plan view of the upper flange level of the S-shaped beam 3, and FIGS. 4 (2) and 4 (3) are vertical. A cross-sectional view is shown.
As shown in FIG. 4, the S-shaped beam 3 positioned on both sides of the column 1 is extended to the column face surface, and the end of the S-shaped beam 3 is provided with a bearing plate 4 in contact with the column face surface. Only the outer side of the column 1 is configured so that the S-shaped beam 3 is closely attached. In this figure, the flange at the end of the S-shaped beam 3 is expanded to 37 both vertically, but as shown in FIG. 2, the upper flange connection plate 35 is located above the upper flange, and the lower flange connection plate 36 is located below the lower flange. May be arranged. An upper end joint rebar 51 is disposed above the upper flange, and a lower end joint rebar 52 is disposed below the lower flange with a predetermined rebar spacing.
Through-holes for joining reinforcing bars are provided in the bearing plate 4 arranged at the ends of the S-shaped beam 3 located on both sides of the RC column 1, and the upper joining joint 51 and the lower joining joint 52 are inserted into this. It is penetrated and fixed and integrated with a fixing nut 54. FIG. 4 (2) is an embodiment in which joining reinforcing bars are arranged only on the outer side of the flange of the S-shaped beam 3, and FIG. It is an example.
FIG. 4 (3) shows an example in which the fixing nuts 54 are attached on both sides of the bearing plate 4, and shows the fit that can transmit stress in both the compression and tension directions to the jointed reinforcing bar via the bearing plate 4. ing.
This structure also has the advantage of being able to perform on-site work quickly without being affected by the weather, but the thickness of the bearing plate 4 is sufficiently large so that the fixing degree does not decrease due to out-of-plane bending deformation of the bearing plate 4. It is necessary to be careful to ensure.

FIG. 5 shows an embodiment in which the S-shaped beam 3 is present only on one side of the RC column 1 like a column located at the end of the building. FIG. FIG. 5 (2) and FIG. 5 (3) show vertical sectional views of the upper flange level of FIG.
As shown in FIG. 5, when the S-shaped beam 3 is present only on one side of the RC column 1, the S-shaped beam 3 is extended to the column face surface, and the column face surface is formed at the end of the S-shaped beam 3. The bearing plate 4 in contact with the reinforced concrete column 1 is provided, and only the outside of the reinforced concrete column 1 is arranged in close contact with the S-shaped beam 3. An upper flange connection plate 35 is disposed above the upper flange of the end of the S-shaped beam 3 and a lower flange connection plate 36 is disposed below the lower flange. An upper end joint rebar 51 is disposed above the upper flange connection plate 35, and a lower end joint rebar 52 is disposed below the lower flange connection plate 36 with a predetermined rebar spacing. It is fixed and integrated with either a fixing coupler or a nut fixing to the bearing plate. One or more PBL dowels 43 are disposed inside the bearing plate 4 disposed at the end of the S-shaped beam 3. The ends of the upper end rebar 51 and the lower end rebar 52 opposite to the ends fixed to the S-shaped beam 3 are mechanical fixing, bending fixing, U-type fixing in which both are bent and integrated, Any one of the above-mentioned fixing systems is adopted.
FIG. 5 shows the case where the S-shaped beam 3 and the joining rebars 51 and 52 are joined by welding. However, as in the second or third embodiment, coupler joining or nut fixing to the bearing plate 4 is applied. You can also.
When the S-shaped beam 3 is present only on one side of the RC column 1, the fixing structure of the end portion of the joining reinforcing bar opposite to the S-shaped beam 3 side is important. FIG. 5 (2) shows an example using a mechanical fixing device 55. FIG. 5 (3) shows a structure in which the upper joining bar 51 and the lower joining bar 52 are respectively bent and fixed, or a structure in which both are made continuous to form a U-type fixing 56.
FIG. 5A shows an embodiment in which the mechanical fixing device 55 and the U-type fixing device 56 are mixedly arranged. It is shown that by using this fixing method in combination, the stress concentration generated in the concrete of the fixing portion is alleviated, the interval between the reinforcing bar fixing portions is ensured, and the reinforcement of the reinforcing bar fixing portion fits cleanly.

FIG. 6 shows an embodiment in which the structure of the end portion of the S-shaped beam 3 is different. (1) is a plan view of the upper flange level of the S-shaped beam 3, (2) is a vertical sectional view, (3) Is a plan view of the lower flange level.
In the present invention, since the joining reinforcing bars are used for fixing the end portion of the S-shaped beam 3, if the required number is arranged in parallel at a predetermined interval, a width wider than the flange width of the H-shaped steel is required. In order to solve this problem, the connection plates 35 and 36 are attached to the end portions of the S-shaped beam 3 in the first embodiment. However, in the fifth embodiment, the end portions of the S-shaped beam 3 are used as the built-in H in advance. The widened flange 37 is widened to the flange width. Since the S-shaped beam 3 is provided with a bolt joint portion 38 as shown in FIG. 1, if only the portion located between the joint portion 38 and the column 1 is configured as a built-in H, the cost increase does not increase. .
In addition, the structure as a flange which widened the edge part of the S-shaped large beam 3 previously is also employ | adopted also in FIG. 3, FIG.

FIG. 7 shows an embodiment in which a large beam in both X and Y directions is an S-shaped beam. (1) is a plan view of the upper flange level of the S-shaped beam, and (2) is a vertical sectional view.
In the sixth embodiment, the S-shaped beam 3 is extended to the column face surface in both directions, and the end of the S-shaped beam 3 is provided with a bearing plate 4 in contact with the column face surface so that the RC column 1 faces. It is set as the structure by which the S-shaped large beam 3 is closely_contact | adhered only to the outer side of both sides | surfaces. The S-shaped beam 3 in one direction (X direction in the figure) on both sides of the RC column 1 is joined and integrated with the flange or flange connection plate of the S-shaped beam 3 by welding the upper joint bar 51X and the lower joint bar 52X. It has become. In the S-shaped beam 3 in the other direction (Y direction in the figure), the upper joint bar 51Y and the lower joint bar 52Y are fixed to and integrated with the bearing plate 4 by nuts. One or more (two in this figure) PBL dowels 43 are disposed inside the column / beam joint of the bearing plate 4 disposed at the end of the S-shaped beam 3.
When the S-shaped beams 3 are arranged in both the X and Y directions, it is desirable to align the upper end levels of the steel beams in both directions to be the same while crossing the joining bars in both directions.
As shown in FIG. 7 (1), the X-direction (horizontal direction) beam has a built-in H-end at the beam end, and employs a structure in which the joining rebar is fixed by welding. The height of the is kept to a minimum. On the other hand, end connection plates 35 and 36 are arranged at the end of the S-shaped beam 3 in the Y direction (vertical direction in the figure), and a nut fixing method for joining the reinforcing bars to the bearing plate 4 is adopted. , It is possible to secure a level difference at which the joining bars in the XY directions can cross each other, and to align the upper end levels of the steel beams in the XY directions to be the same.

  As shown in the vertical cross-sectional view of FIG. 7 (2), the column / beam joint 16 according to this method is surrounded by joint bars in both the X and Y directions at the top and bottom, and the periphery is a Hop bar that penetrates the hole of the PBL gibber 43. It is restrained. Since there are no steel members or reinforcing bars that impede the filling of concrete other than the PBL gibber 43 inside the column / beam joint 16, it is easy to place and fill concrete, and high quality columns / beams The joint 16 can be constructed.

FIG. 8 shows an embodiment in which the web plate 34 of the S-shaped beam 3 is penetrated into the column / beam joint. FIG. 8A is a plan view of the upper flange level of the S-shaped beam, FIG. 2) is a vertical sectional view, and FIG. 8 (3) is a plan view of the lower flange level.
In FIG. 8A, the web plate 34 of the S-shaped beam 3 is extended into the column / beam joint 16, and a hole 44 is formed in the web plate 34, so that the web plate 34 is also used as a PBL dowel. However, the web plate 34 is not continuous, and the upper and lower flanges 32 are cut to a small width so as not to obstruct the arrangement of the column main bars 11 and the concrete placement.
8 (2) and 8 (3) show the case where the web plate 34 of the S-shaped beam 3 is extended so as to be continuous with the S-shaped beam 3 on both sides of the column, and the upper and lower flanges 32 are cut to a small width. Thus, the arrangement of the column main bars 11 and the concrete placement are not obstructed.

FIG. 9 is an embodiment showing the shape of the bearing plate 4 provided at the end of the S-shaped beam 3. FIG. 9 (1) is a vertical sectional view as seen from the side, and FIGS. 9 (2) and 9 (3) are supports. FIG. 3 is an elevation view seen from the front of the pressure plate 4.
As shown in FIG. 9 (1), the height of the bearing plate 4 is larger than the positions of the upper joint bar 51 and the lower joint member 52, and the width of the bearing plate 4 is larger than the entire width of the joint bars arranged horizontally. Configure. Further, in order to suppress out-of-plane deformation when a compressive force (support pressure) is applied to the support plate 4, support plate reinforcing ribs 41 are arranged. The vertical rib 42 that receives the reinforcing rib 41 has a role of restraining the flange 31 of the S-shaped beam 3 and the out-of-plane deformation of the connection plates 35 and 36 together with the reinforcement of the supporting rib reinforcing rib 41. .

In the bearing plate 4 shown in FIG. 9 (2), a U-shaped slit 46 is provided so that the horizontal position of the upper end joint rebar 51 and the position adjustment of the vertical level can be easily adjusted. This is designed so that the upper end joint rebar 51 can perform the on-site reinforcing work with high accuracy even after the orthogonal RC beam is placed.
FIG. 9 (3) shows a case where both the upper end joint rebar 51 and the lower end joint rebar 52 are arranged through the through holes of the bearing plate 4, and the inner side (column side) of the bolt joint 38 of the S-shaped beam 3 is manufactured in advance in the factory. If you want to.
By simply providing the through-hole 47 in the bearing plate 4 for the arrangement of the joint reinforcing bars, it is configured as a single continuous rectangular plate, and further, by combining the reinforcing rib 41 for preventing out-of-plane deformation, it is stronger and more out-of-plane. A highly rigid bearing plate is realized.

FIG. 10 is an embodiment in which the lower end of the bearing plate 4 can be supported by the concrete of the column 1, (1) is a plan view of the upper flange level of the S-shaped beam 3, and (2) and (3) are vertical sectional views. It is.
The basic structure of the present invention is that the S-shaped beam 3 is stopped at the column face position, and the S-shaped beam 3 does not hinder the arrangement of the column bars. A bearing plate 4 is provided at the end of the S-shaped beam 3, and the vertical load (vertical shearing force) of the S-shaped beam 3 is a PBL divel provided inside the bearing plate (inside the column / beam joint). The basic configuration is to transmit at 43.

The ninth embodiment is configured such that the column concrete 13 is present under the bearing plate 4, and has an extra force with respect to the vertical shearing force transmitted from the beam to the column, thereby enhancing the sense of security. It is.
FIG. 10 (2) shows a case where the column cross section is enlarged only in a certain range immediately below the bearing plate 4, and the vertical shear strength by the concrete 13 supporting the bearing plate 4 can be adjusted by setting the height.
FIG. 10 (3) is an example in which the column cross-section widened portion 14 for taking the thickness of the bearing plate 4 into the column is enlarged over the entire column height by the thickness of the bearing plate 4. Since the bearing plate 4 is hidden in the column and cannot be seen, the design is beautiful and the reliability is high from the viewpoint of fire safety.

FIG. 11 shows the relationship between the PBL gibber 43 and the shear reinforcement (Hoop) 12 related to the shear strength of the column / beam joint 16. FIG. 11 (1) shows the upper flange level of the S-shaped beam 3. A plan view, FIG. 11 (2) is a vertical sectional view.
The PBL dowel 43 is a steel plate having a large number of through holes 44 having a diameter of about 35 mmφ to 50 mmφ, and is fixed to the bearing plate 4 and arranged in the vertical direction. Shear strength is exhibited by two-plane shearing between the concrete filled in these through holes 44 and the surrounding concrete. It is known that when a reinforcing bar is passed through the through hole 44, the toughness (deformation performance) as a shear force gibber is improved.
In the tenth embodiment, the PBL dowel 43 is disposed in the column / beam joint, and at the same time, the shear reinforcement (Hoop) 12 disposed on the outer periphery of the column / beam joint is penetrated into the through hole 44. Thus, the role of the Hope muscle 12 for improving the toughness of the PBL gibber 43, restraining the column / beam joint 16 and securing the shear strength is satisfied at the same time.

As can be seen from FIG. 11 (2), the PBL dowel 43 in the vertical direction is only present in the column / beam joint 16 surrounded by the Hope bar 12, so that it is easy to place and fill the concrete. It is easy to construct a high-quality column / beam joint 16.
In addition, in order to allow the Hop line 16 to penetrate the PBL dowel 43, the Hop line of that part needs to be a straight line. For this reason, after the hop line 16 is divided into a U-shaped, L-shaped or straight line into the through-hole, it is made a closed type hop line by welding or the like.

FIG. 12 shows an embodiment in which the stud bolt 45 is used as a structure for transmitting the shearing force of the S-shaped beam 3 to the column / beam joint, and (1) is a plan view of the upper flange level of the S-shaped beam 3. , (2) is a vertical sectional view, and (3) is a plan view of the lower flange level.
In the eleventh embodiment, a case where the web plate 34 of the S-shaped large beam 3 is continued in the column / beam joint portion and the S-shaped large beams 3 on both sides of the column are connected is shown. The stud bolt 45 is driven on the bearing plate 4 and is also attached to the central web plate 34. Further, a hole 44 is arranged in the web plate 34 continuously penetrating through the column / beam joint portion, and also has a function as a PBL dowel.
Furthermore, as shown in FIG. 12 (2), the web plate 34 is provided with a through-hole 44 so as to pass the main bar 21 of the RC beam in the orthogonal direction. It also has the effect of greatly increasing the ultimate shear strength of column / beam joints.

  In the present invention, the following three special considerations are given to the concrete constituting the column / beam joint. First, as the first point, in the present invention, the filling and honeying properties of the concrete at the column / beam joint are important, and for this reason, the concrete placement and filling properties are drastically improved in construction. That is. In other words, in the conventional mixed structure frame, the H-shaped steel of the beam penetrates into the column / beam joint, so it is extremely difficult to fill the concrete under the flange without any gaps. Even with a full-scale mock-up experiment, it was confirmed that there was a gap under the flange. The present invention basically eliminates the intrusion of the S-shaped large beam from the column / beam joint, and solves this problem itself. Also, when the S-shaped beam is inserted into the column / beam joint, the web plate is mainly used as shown in FIG. 8 and FIG. 12, and the flange width is set so as not to obstruct the column arrangement and concrete placement. Large excision.

  The second point is consideration for securing and raising the shear strength of the column / beam joint. Previous studies have shown that the shear strength does not increase easily even if the shear reinforcement bars (Hoop bars) at the column-beam joints are increased. As a countermeasure, the present invention adopts a measure for increasing the design reference strength Fc only for the concrete to be placed at the column beam joint, rather than the concrete of the floor slab or the orthogonal RC large beam. For example, as a concrete strength of each part of the building, a building designed with a slab Fc = 24 to 27 (N / mm2), a beam Fc = 24 to 30 (N / mm2), and a column Fc = 27 to 36 (N / mm2) In this case, concrete with Fc = 36 to 45 (N / mm 2), or Fc = 60 (N / mm 2) or more is used for the column / beam joint. If high-strength concrete is used, the material cost will be high, but since the part to be used is limited to the column / beam joint only, the cost of the entire building will not be increased, and the shear of the column / beam joint will be reduced. The yield strength can be increased efficiently and economically.

The third point is to prevent the joint concrete from shrinking as an important condition for the concrete of the column / beam joint. The column / beam joint is usually shaped like a cube with a side of about 1 m depending on the column size, and becomes mass concrete. Therefore, there is a possibility that drying shrinkage will increase with the heat generated during concrete hardening. If the concrete at the column / beam joint shrinks and a gap occurs even on the back side of the bearing plate 4, the bearing pressure generation function of the bearing plate 4 will be impaired, reducing the shrinkage or preventing shrinkage of the column / beam junction concrete. It is necessary to plan.
Many factors in the materials used and the environment affect the shrinkage caused by the hardening and drying of the concrete, but unless special consideration is given, the drying shrinkage strain of the concrete is about ε = (8-10) × 10-4 It is known to reach In this case, if the width of the column-beam joint is L = 1 m, the contraction amount δ is about δ = εxL = 0.8 to 1.0 mm, and about 0.4 to 0.5 mm on the left and right bearing plates. There may be gaps.
In the present invention, the goal of quality control is to suppress the drying shrinkage distortion of the concrete placed in the column / beam joint to less than half of the above, that is, to suppress to ε = (0-4) × 10−4 or less. And As a result, the gap generated between the left and right bearing plates is 0 to 0.2 mm or less, and an almost perfect fixing degree can be realized for the S-shaped beams on both sides of the column.
To achieve this, the concrete that composes the column / beam joint is subjected to advanced blending design including shrinkage control so that the drying shrinkage can achieve the above target value, including cement and aggregate. In addition to using materials with excellent shrinkability, addition of admixtures / additives and swelling agents that are effective in reducing shrinkage is used. In particular, when the concrete of the column / beam joint is made of expansive concrete, a compressive stress field is introduced into the column / beam joint by chemical pre-stress, and an extremely excellent column / beam joint can be realized.
As described above, in the present invention, by adopting concrete having excellent drying shrinkage for the column / beam joint, it is possible to realize a column / beam joint that can sufficiently exhibit the excellent structural performance of the present invention.

As described above, when the mixed structural beam of the present invention is adopted, a large-scale building with a span exceeding 10 meters between pillars or a large structure with a large loading load and a dominant stress due to a long-term vertical load is economically constructed. Can be realized with high reliability and high reliability. In addition, since a horizontal rigidity higher than that of the S-framework generally adopted for structures having a large span can be secured, it is possible to realize a structure excellent in earthquake resistance and wind resistance.

1: RC column 11: Column main reinforcement 12: Column shear reinforcement (Hoop reinforcement)
13: Concrete part under the bearing plate 14: Column cross-section widened part for taking in the thickness of the bearing plate into the column 15: Reinforcing plate surrounding the column / beam joint 16: Column / beam joint

2: R / C RC beam in orthogonal direction 21: Main bar of R / C RC beam in orthogonal direction 22: Shear reinforcement of RC beam 23: S beam 24: Floor slab

3: S-shaped beam 31: S-shaped beam flange 32: Width cut flange in the column / beam joint 33: S-shaped beam web plate 34: S-shaped beam web plate extended to the column / beam joint 35: Upper flange connection plate at the end of the S-shaped beam end 36: Lower flange connection plate at the end of the S-shaped beam end 37: Widening flange for the connection plate by the built-in H at the end of the S-shaped beam 38: Bolt jointed portion of the S-shaped beam end

4: bearing plate 41: reinforcing rib for bearing plate 42: reinforcing rib of connection plate 43: PBL dowel 44: PBL dowel hole 45: stud bolt 46: U-shaped slit of bearing plate 47: through hole for joint reinforcing bar of bearing plate

5: S-shaped steel beam joint reinforcement 51: Top joint reinforcement 51X: Upper joint joint in the X direction 51Y: Upper joint joint in the Y direction 52: Bottom joint reinforcement 52X: Bottom joint in the X direction 52Y: Lower joint joint in the Y direction 53: Joint reinforcement Mechanical coupler 54: Nut for fixing jointed rebar 55: Mechanical fixing tool for joined rebar 56: U-shaped bending fixing of joined rebar

Claims (13)

The structure is a reinforced concrete structure (hereinafter referred to as “RC structure”), and at least one of the two horizontal horizontal beams is a steel structure (hereinafter referred to as “S structure”). The framework,
The S-shaped beam is extended to the boundary surface between the columns (hereinafter referred to as “column face surface”), and an end of the S-shaped beam is provided with a bearing plate in contact with the column face surface. The S-shaped beam is arranged in close contact with only the outside of the opposite side surfaces,
An upper flange connection plate is disposed above the upper flange of the S-shaped beam end, and a lower flange connection plate is disposed below the lower flange;
Upper end joint rebars are arranged in parallel with a predetermined rebar spacing on the upper side of the upper flange connection plate on both sides of the RC pillar, and both ends thereof are fixed and integrated with the upper flange connection plate.
Lower end joint rebars are arranged in parallel with a predetermined rebar spacing on the lower side of the lower flange connection plate on both sides of the RC column, and the ends thereof are fixed and integrated with the lower flange connection plate.
One or more vertical plates with holes (hereinafter referred to as “PBL gibber”) are arranged inside the column / beam joint of the bearing plate arranged at the end of the S-shaped beam. Mixed structural framework. It is a mixed structural framework in which the column is an RC column, the large beam in at least one of the two horizontal directions is an S column, and the S column is present on both sides of the RC column.
The S-shaped beam is extended to the column face surface, and a supporting pressure plate in contact with the column face surface is provided at the end of the S-shaped beam, and the S structure is formed only on the outer sides of the opposite sides of the RC column. A structure in which large beams are closely arranged,
An upper flange connection plate is disposed above the upper flange of the S-shaped beam end, and a lower flange connection plate is disposed below the lower flange;
The upper end joint rebars are arranged in parallel with a predetermined rebar spacing above the upper flange connection plate on both sides of the RC pillar, and both ends thereof are fixed and integrated with the upper flange connection plate.
The lower end joint reinforcing bars are arranged in parallel at a predetermined reinforcing bar interval on the lower side of the lower flange connecting plate on both sides of the RC pillar, and the end portions are fixed and integrated with the lower flange connecting plate,
One or more PBL dowels are arranged inside the column / beam joint of the bearing plate arranged at the end of the S-shaped large beam ,
A mixed structural frame characterized in that a band streak surrounding the column / beam joint is passed through the hole of the PBL dowel . The mixed structural framework according to claim 1 or 2,
Both ends of the upper joint bar are fixed and integrated on the upper side of the upper flange connection plate by welding,
A mixed structural frame , wherein both ends of the lower end joint reinforcing bar are fixed and integrated to the lower side of the lower flange connection plate by welding . The mixed structural framework according to claim 1 or 2,
Reinforcing bar fixing couplers or long nuts (hereinafter referred to as “fixing couplers”) in parallel with a predetermined distance above the upper flange connection plate and below the lower flange connection plate on both sides of the RC pillar. ) Is welded,
A mixed structural frame , wherein the upper end joining reinforcing bar and the lower end joining reinforcing bar are inserted into the fixing couplers on both sides of the RC pillar and fixed and integrated by grout filling . The mixed structural framework according to claim 1 or 2,
Reinforcing bar fixing through holes are provided at predetermined intervals in the bearing plates on both sides of the RC pillar,
The upper end joint rebar and the lower end joint rebar are inserted and penetrated through the through holes of the bearing plate on both sides of the RC column, and both the outside or the inside and outside of the bearing plate are fixed and integrated with nuts. Characteristic mixed structural framework. It is a mixed structural framework in which the column is an RC column, the large beam in at least one of the two horizontal directions is an S column, and the S column is only on one side of the RC column.
The S-shaped beam is extended to the column face, and an end of the S-shaped beam is provided with a bearing plate in contact with the column face, and the S-shaped beam is closely attached only to the outside of the RC column. And the configuration
One or more PBL dowels are arranged inside the column / beam joint of the bearing plate arranged at the end of the S-shaped beam, and the holes of the PBL dowel are connected to the pillar / beam joint. Through the band that surrounds it,
An upper flange connection plate is disposed above the upper flange of the S-shaped beam end, and a lower flange connection plate is disposed below the lower flange;
An upper end joint rebar is disposed above the upper flange connection plate, and a lower end joint rebar is disposed below the lower flange connection plate with a predetermined rebar spacing. Is fixed and integrated in one of the following structures: welding, fixing with a coupler, and fixing nuts to the bearing plate.
U-type fixing in which the end opposite to the end fixed to the S-shaped beam of the upper end joining rebar and the lower end joining rebar is mechanical fixing, bending fixing, and both are bent and integrated, A mixed structure frame characterized by adopting a fixing structure of any of those mixing methods . In the mixed structural framework according to any one of claims 1 to 6,
The mixed structural frame is characterized in that the ends of the upper and lower flanges of the S-shaped beam are widened and configured in advance as a wide connecting plate . The mixed structural framework according to claim 1 or 2,
The S-shaped beam is extended to the column face surface in both directions, and a bearing plate that is in contact with the column face surface is provided at the end of the S-shaped beam, and only on the outer sides of the opposite sides of the RC column. S construction large beams are arranged in close contact,
The unidirectional S-shaped beams on both sides of the RC column are joined and integrated with the flange or flange connection plate of the S-shaped beam by welding the upper joint and the lower joint.
A mixed structural frame characterized in that the S-shaped beam in the other direction is fixed and integrated with the bearing plate using a nut or a fixing coupler . In the mixed structure frame according to any one of claims 1 to 8,
A mixed structural frame characterized in that the web plate of the S-shaped beam is extended to the inside of the column / beam joint inside the bearing plate and also used as the PBL gibber . In the mixed structural framework according to any one of claims 1 to 9,
Mixing characterized in that horizontal and vertical reinforcing ribs for suppressing out-of-plane deformation of the bearing plate are arranged at the end of the S-shaped beam located outside the column / beam joint of the bearing plate. Structural framework. The mixed structural framework according to any one of claims 1 to 10,
A through hole or a U-shaped slit slightly larger than the diameters of the upper end joining rebar and the lower end joining rebar is provided at a position where the upper end joining rebar and the lower end joining rebar of the bearing plate pass. Mixed structure framework to do. In the mixed structure frame according to any one of claims 1 to 11,
Either the bearing plate is embedded in the column / beam joint from the column face surface and outside the column main bar, or the column width at the bottom of the bearing plate is widened, A mixed structural frame, wherein a bottom portion of the bearing plate is supported by concrete of the RC column . The mixed structural framework according to any one of claims 1 to 12,
Mixing characterized by adopting concrete with low drying shrinkage or expansible concrete as the concrete that constitutes the column-beam joint, and increasing the design standard strength of the concrete compared to the concrete of other parts Structural framework.