JPH0730587B2 - Structure of joint between column and beam - Google Patents

Description

TECHNICAL FIELD The present invention relates to a structure of a joint portion between a precast concrete beam and a filled steel tube concrete column.

“Conventional technology and problems” Conventionally, in order to join a precast concrete beam to a filled steel tube concrete column, which is one form of steel-framed reinforced concrete structure, the rebar or steel frame part of the precast concrete beam having a span between columns is The method of joining the steel pipe and the beam to the steel pipe by welding from all sides was adopted. However, in the above-mentioned construction method, four joints are required for each pillar, which is inefficient, resulting in a longer construction period and an increase in construction cost.

The present invention has a problem how to realize a structure of a joint portion between a pillar and a beam, which can easily join a filled steel pipe concrete column and a precast concrete beam.

"Means for Solving the Problems" The present invention is to join a concrete-filled steel pipe concrete column, in which steel pipe is filled with concrete, to the upper and lower sides of a precast concrete beam with their axes aligned with each other. The structure of the joint between the pillar and the beam in the form of
Reinforcing members such as reinforcing bars vertically penetrate the beam, and the upper and lower end portions of the reinforcing members are inserted into the respective steel pipes by a predetermined size and embedded in concrete in the respective steel pipes. .

In this case, it is preferable to provide an unbonded layer on the boundary surface between the steel pipe and concrete.

[Operation] In the present invention, the beam is horizontally penetrated at the joint between the column and the beam, and the columns are joined above and below the beam, respectively. Then, the upper and lower end portions of reinforcing members such as reinforcing bars penetrating the beam in the vertical direction are embedded and fixed in the concrete of the upper and lower columns for a predetermined length, respectively, and the beam and the column are connected via the reinforcing member. Will be firmly joined.

Further, when the unbonded layer is provided on the boundary surface between the steel pipe and the concrete, the steel pipe and the concrete do not behave integrally.

[Examples] Examples of the present invention will be described below with reference to the drawings.

1 and 2 are views showing a structure of a joint portion between a column and a beam which is an embodiment of the present invention. 1 to 2
In the figure, a joint portion 1 between a pillar and a beam is a precast concrete (hereinafter referred to as PC) beam 2 that extends through the joint portion 1 in the horizontal direction of the building and a height direction of the building. Is arranged between the upper and lower joints 1 and 1, that is, between the lower surface of the PC beam 2 on the upper floor and the upper surface of the PC beam 2 on the floor immediately below, and the height between the beams 2 and 2 is increased. A column 5 made of a filled steel pipe concrete filled with concrete 4 inside a steel pipe 3 and a pipe 5 are arranged to penetrate the joint 1 in the longitudinal direction of the column 5 to a required position in the steel pipe 2. And a plurality of reinforcing bars (reinforcing members) 6, 6 ...

The PC beam 2 is formed by two I-shaped cross-section PC beams intersecting each other in a cross shape, and is formed in the thickness direction near the center of the intersection corresponding to the joint 1. Through hole 7
Are formed. Further, small holes 8, 8 ... Through which the reinforcing bars 6 are inserted are formed around the hole 7 of the PC beam 2.

The reinforcing bar 6 is inserted into the small hole 8 of the PC beam 2 and both ends thereof are located in the steel pipes 3 and 3 with the PC beam 2 interposed therebetween. At both ends of the reinforcing bar 6, concrete 4 is cast around the both ends and is restrained by the steel pipes 3, so that sufficient fixation is achieved.

Next, with reference to FIG. 1 to FIG. 3, a method of constructing a structure of a joint portion between a pillar and a beam, which is one embodiment of the present invention, will be described.

First, the distance between the upper and lower PC beams 2, 2 (ie, the upper PC beam 2
The distance between the lower surface of the PC and the upper surface of the PC beam 2 on the floor immediately below) inside the steel pipe 3, leaving concrete space for the reinforcing bar 6 at the upper end, and placing concrete 4 To do. Next, the PC beam 2 is placed on the upper end surface of the steel pipe 3, and the reinforcing bars 6, 6, ... are inserted into the small holes 8, 8, ... of the PC beam 2 and fixed (see Fig. 3). ). Although the method of fixing the reinforcing bar 6 is arbitrary, for example, after inserting the reinforcing bar 6 into the small hole 8, the small hole 8 is fixed.
A method of injecting grout into the inside can be considered.

Then, after newly building the steel pipe 3 on the upper surface of the PC beam 2,
As described above, the concrete 4 is poured while leaving the void at the upper end. Then, the concrete 4 is also poured and filled into the space at the upper end of the steel pipe 3 located below the PC beam 2 through the hole 7 of the PC beam 2. Here, since the lower end surface of the steel pipe 3 located above the PC beam 2 is often not entirely covered by the upper surface of the PC beam 2, it is necessary to provide a closing means such as a pressure plate at this opening.

Then, the above steps are repeated to build the building. Here, each PC beam 2 is connected to the joint 1 on the floor,
After the constructions of 1, ... Are completed, they may be joined at appropriate positions between the columns 5, 5.

The joint portion 1 between the pillar and the beam is constructed by the method described above. Here, at this joint 1, the PC beam 2 penetrates this joint 1 and extends in the horizontal direction of the building.
The length of the beam 2 is not limited to the span length between the pillars 5 and 5 as in the conventional case, but can be integrally enlarged. Further, the connection between the pillar 5 and the beam 2 is also performed by penetrating the reinforcing bar 6 in the thickness direction of the PC beam 2 and fixing both ends of this to the steel pipes 3 and 3 with concrete 4, so that the concrete 4 The reinforcing bars 6 are naturally embedded and fixed in the concrete 4 and firmly fixed only by placing the pillars. Therefore, the conventional general joint structure, that is, the pillars are vertically penetrated at the joints, The columns and beams can be connected much more easily and the reinforcing bars as reinforcing members can be connected to the steel pipes of four sides by individually welding the reinforcing bars or steel frames of the PC beams. 6, it is possible to secure sufficient bonding strength.

FIG. 4 is a diagram showing a structure of a joint between a column and a beam which is a modified embodiment of the present invention. The difference from the embodiment is that the boundary surface between the steel pipe 3 and the concrete 4 is different. The point is that an unbonding treatment layer 9 is provided to eliminate the adhesion of the concrete 4 to the steel pipe 3. The unbonded layer 9 is formed by coating the inner surface of the steel pipe 3 with paraffin, asphalt, oil, grease, vaseline or the like.
In this case, it is preferable to provide a deformation absorbing portion 10 formed of a circumferential slit in the middle of the steel pipe 3. As described above, when the unbonded layer 9 is provided on the boundary surface between the steel pipe 3 and the concrete 4, the steel pipe 3 and the concrete 4 do not behave integrally, and therefore the PC beam 2 is transmitted to the steel pipe 3. The axial compressive stress is completely absorbed by the deformation absorbing portion 10, while the circumferential expansion generated in the concrete 4 is suppressed by the confined effect of the steel pipe 3. Therefore, it becomes possible to remarkably improve the compressive strength of the filled steel pipe concrete column 5 and reduce its cross-sectional area.

The structure of the joint between the pillar and the beam according to the present invention is not limited to the above embodiment. For example, without forming the PC beam 2 in a cross shape, one of the PC beams having an I-shaped cross section is joined to the joining portion 1
And the other PC beam with an I-shaped cross-section
The structure may be such that it is joined to the PC beam in two directions. Further, instead of the reinforcing bar 6, the joining portion 1 may be reinforced by a fixing bolt or the like.

"Effects of the Invention" As described in detail above, according to the present invention, the PC beam is horizontally penetrated in the joint portion and the filled steel pipe concrete columns are joined to the upper and lower portions thereof, respectively.
It is possible to form the PC beam by enlarging it integrally, and in particular, the reinforcing member that penetrates the PC beam up and down is embedded in the concrete of each column for a predetermined length, so that The reinforcement member is embedded and fixed in the concrete only by placing the concrete, and it is firmly anchored, which secures the sufficient joint strength between the column and the beam, and in addition to the steel pipe of the column, Therefore, the construction can be remarkably easily performed as compared with the conventional general case in which the reinforcing bars or steel frames of the PC beam are usually welded and joined individually.

Further, when an unbonded layer is provided on the boundary surface between the steel pipe and concrete, the axial compressive stress transmitted from the precast concrete beam to the steel pipe is completely absorbed by the deformation absorbing section, while the circumferential pressure generated in the concrete is absorbed. The directional expansion is suppressed by the confined effect of the steel pipe. Therefore, it becomes possible to remarkably improve the compression strength of the filled steel pipe concrete column and to reduce the cross-sectional area thereof.

[Brief description of drawings]

FIG. 1 is a front view of a cross-section of a main part showing the structure of a joint between a column and a beam, which is an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the line II ′ of FIG. FIG. 3 is a perspective view showing a state in which the joint portion is being constructed, and FIG. 4 is a front view showing a sectional view of a main portion showing a structure of a joint portion between a column and a beam which is a modified embodiment of the present invention. 1 …… Joint part, 2 …… Precast concrete beam, 3
…… Steel pipe, 4 …… Concrete, 5 …… Column, 6 …… Reinforcing bar (reinforcing member), 9 …… Unbonded layer.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshihiro Shimodo 2-16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (72) Hideo Nakajima 2--16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction company (72) Inventor Yasushi Watanabe 2-16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction company

Claims (2)

[Claims] 1. A connection between a column and a beam of a precast concrete beam, wherein columns of a filled steel pipe concrete structure in which steel pipes are filled with concrete are joined together with their axes aligned with each other. The structure of the part,
Reinforcing members such as reinforcing bars vertically penetrate the beam, and upper and lower end portions of the reinforcing members are inserted into the respective steel pipes by a predetermined size and embedded in concrete in the respective steel pipes. The structure of the joint between the pillar and the beam. 2. An unbonded layer for preventing the concrete from adhering to the steel pipe is provided on the boundary surface between the steel pipe and the concrete poured and filled therein. The structure of the joint portion between the column and the beam according to the first paragraph.