JPH06272311A - Connecting structure of precast concrete column and steel framed beam - Google Patents

Abstract

PURPOSE:To increase the shearing force of the concrete of the bracket section of a semi-PC column, to similify a method of the arrangement of reinforcements for reinforcement for shear, to reduce the quantity of the reinforcements arranged and to simplify execution while improving the rational stress transmission of a connecting section and toughness. CONSTITUTION:Bracket sections 2b formed in a U shape so that the end sections of steel framed beams 3 can be placed and a semi-PC column 2 with a plurality of upper-end main reinforcements 7a and lower-end main reinforcements 7b connected to the steel framed beams 3 are installed to the capital section of a PC column 1. Band plates 12 fitted at the end sections of the bracket sections 2b at end sections and the end sections of the steel framed beams 3, to which fixing plates 11, on which the upper-end main reinforcements 7a and the lower-end main reinforcements 7b are fixed, are mounted, are placed on the bracket sections 2b of the semi-PC column 2. The band plates 12 are fitted at the front end sections of the bracket sections 2b, the beam upper-end main reinforcements 7a and the lower-end main reinforcements 7b are fastened to the fixing plates 11, and concrete is placed to the U-shaped insides of the bracket sections 2b and the upper sections of the bracket sections 2b, thus constructing the connecting sections of the bracket sections 2b and the steel framed beams 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for joining precast concrete columns and steel beams in a composite structure comprising precast concrete columns and steel beams.

[0002]

2. Description of the Related Art Conventionally, in a joint construction method of a precast concrete column and a steel beam in a composite structure of this type, a normal deformed reinforcing bar is arranged on each of the upper and lower main bars of a bracket portion formed of precast concrete in a U shape. The U-shaped ribs, the secondary ribs extending over the upper and lower main bars, and the cap tie and / or the inverted U-shaped ribs that are attached after the steel beam is reinforced. Are reinforced and concrete is placed on the bracket portion to enhance the rigidity and proof stress of the bracket joint portion.

[0003]

However, in such a conventional joining construction method, in addition to the U-shaped ribs and the cap tie at the position of the upper main bar, the auxiliary ribs extending to the upper and lower main bars or the inverted U-shaped ribs. Since the bars are densely arranged, the amount of reinforcing bars is significantly large, and the reinforcing bar method is also extremely complicated.This not only significantly reduces the filling property of concrete, but also in terms of construction and quality of members. There were problems such as the difficulty of.

Even with such reinforcement, the stress transmission from the steel beam to the bracket portion is caused mainly by the lever action of the steel beam from the upper and lower flange surfaces of the steel beam at the tip portion and the end portion of the bracket portion. The concrete at the tip of the bracket receives a greater amount of bearing pressure, especially because the concrete at the tip of the bracket is subject to splitting cracks and cracks in bearing pressure, and the pull-out reinforcing bars come out. There is also a problem that the stress is not easily transmitted from the steel beam to the bracket portion, and the toughness of the bracket portion is not sufficiently achieved.

Therefore, in order to solve the above-mentioned problems of the prior art, the present applicant increases the shearing force of the concrete of the bracket portion by applying special reinforcement to the joint portion of the bracket portion and the steel frame beam, It simplifies the reinforcement method for shear reinforcement, and further reduces the reinforcement amount, further simplifies the construction and rational stress transmission and improvement of toughness of the joint. We have developed a joint construction method between precast concrete columns and steel beams, which has made it possible (see Japanese Patent Application No. 4-342666).

A joint construction method of a precast concrete column and a steel beam according to the present invention is an improvement and development of the above invention, which simplifies the reinforcement without impairing the proof stress of the joint portion of the bracket portion and the steel beam, This is to further simplify the construction.

[0007]

According to a first aspect of the present invention, there is provided a method for joining a precast concrete column and a steel beam, so that the end of the steel beam can be placed on the column head of the precast concrete column. A semi-precast concrete pillar having a U-shaped semi-precast concrete bracket and a plurality of beam main bars connected to the steel beam is installed, and then the bracket is attached to the end. The band plate fitted to the end of the section, and the end of the steel beam to which the fixing plate to which the beam main bar is fixed is mounted on the bracket part of the semi-precast concrete column, and then, The band plate is fitted to the tip portion of the bracket portion, the beam main bar is fixed to the fixing plate, and the U-shaped inside of the bracket portion and the upper portion thereof are And Da設 cleats, characterized by constructing the junction between the steel beam and the bracket portion.

According to a second aspect of the present invention, the precast concrete column and the steel beam are joined together in a U-shape so that the end of the steel beam can be placed on the column head of the precast concrete column. A semi-precast concrete column comprising a semi-precast concrete bracket formed in a mold and a plurality of beam main bars connected to the steel beam is installed, and then the beam main bars are fixed at the ends. An end portion of the steel beam to which the fixing plate is attached is mounted on a bracket portion of the semi-precast concrete column, and then the beam main bar is fixed to the fixing plate, and a U-shape of the bracket portion. It is characterized in that concrete is cast inside the mold and the upper part thereof to construct a joint portion between the bracket portion and the steel frame beam.

[0009]

According to the joining construction method of the precast concrete column and the steel beam according to the present invention, the semi-precast concrete column is molded in advance at the factory or on-site work site, so that the reinforced concrete panel having the stirrup at the intersection of the bracket portions. As for the part, the construction accuracy is improved and high quality is secured compared with the case of cast-in-place reinforced concrete.

Further, since the projecting end of the beam main bar that resists the tensile force generated in the bracket portion due to the bending moment at the time of earthquake is connected to the steel beam through the fixing plate, the steel beam and the semi-precast concrete column are connected. The stress transmission to and from is reliably and smoothly performed, and adhesion cracking of concrete around the reinforcing bars inside the bracket portion is prevented.

Regarding the shear reinforcement, it is constituted by a U-shaped rib and a cap tie with a hook connected by the crimp joint, and an effect almost equal to that of the closed rib can be expected.

Further, by restraining the band plate located at the tip of the bracket portion, splitting cracks and bearing pressure cracks in concrete caused by bearing pressure on the flange surface of the steel beam can be prevented.

Therefore, at the joint portion of the bracket portion,
It is possible to maintain sufficient resistance to the effect of bending moment as in the case of general reinforced concrete beams, and to the effect of shear force, the shear force transmitted by the truss mechanism of the ribs. Due to the restraint of the force and the band plate and the fixing plate, the shearing resistance due to the superposition of the shearing force transmitted by the concrete arch mechanism is reliably exhibited.

[0014]

【Example】

Example 1. FIG. 1 shows a joint portion between a precast concrete column and a steel beam being constructed by a joint construction method between a precast concrete column and a steel beam according to claim 1 of the present invention. In the figure, reference numeral 1 indicates a predetermined interval. Precast concrete columns built every other (hereinafter "PC
2 is a semi-precast concrete column (hereinafter referred to as "half PC column 2") which is installed on the column head of the PC column 1 and which joins the PC column 1 and the steel beam 3 together.

The PC column 1 is preliminarily formed into a rectangular cross section at a factory or the like, and the upper ends of the column main bars 4, 4 project from the column head by a predetermined length.

The half-PC pillar 2 is formed with a joint panel portion 2a formed in a rectangular cross-sectional shape of approximately the same size as the PC pillar 1, and in a substantially U-shaped cross-section opening directly above, and the joint panel portion. It is formed in a cross shape from four brackets 2b horizontally projecting from the side of 2a (see FIGS. 2, 3, and 4).

It should be noted that not all the half-PC pillars 2 are formed in a cross shape, but are formed in an L-shape or a T-shape (see FIGS. 10 and 11) depending on the installation place.

In the connection panel portion 2a, the main pillars 4, 4 of the PC pillar 1 are
A plurality of through holes 5,5 that can penetrate the upper end of
In addition, there are multiple stirrups (hoop streaks) in the concrete6.
6 are arranged. Further, a plurality of upper-end beam main bars 7a, 7a made of screw rebar are arranged at the upper end of the joint panel section 2a, and both ends of the upper end beam main bars 7a, 7a extend horizontally on all sides of the joint panel section 2a. However, a predetermined length is extended in parallel with the upper side of each bracket portion 2b. In addition, in the concrete of the bracket part 1b, a plurality of lower-end beam main bars made of screw-reinforcing bars
7b, 7b and ribs (stirrup muscle) 8 are arranged.

The lower end beam main bars 7b, 7b are arranged in parallel with the upper end beam main bars 7a, and the tips thereof project a predetermined length from the tips of the bracket portion 2b. The ribs 8 are arranged in a U-shape along the cross-sectional shape of the bracket portion 2b. Further, a plurality of width stop bars 9 are arranged on the upper side of the bracket portion 2b.

Incidentally, the joint panel portion 2a and the bracket portion 2b of the half PC pillar 2 are integrally formed in advance in a factory or the like like the PC pillar 1.

The through holes 5 and 5 of the connection panel portion 2a are filled with mortar or grout after inserting the column main bars 4 and 4, and the semi-PC column 2 is completely fixed to the column head of the PC column 1. ing.

The H-shaped steel is used for the steel beam 3, and the end plates 10 attached to the side surfaces of the joint panel 2a are attached to both ends of the steel beam 3 by welding.

Further, a fixing plate 11 attached to the tip of the bracket portion 2a and a band plate 12 fitted to the tip of the bracket portion 2a are provided inwardly of both ends of the steel frame beam 3, respectively. It is installed.

The steel plate beam 3 penetrates through the central portion of the fixing plate 11, and the band plate 12 is formed in a rectangular ring shape that can be fitted to the tip portion of the bracket portion 1a, and the peripheral portion of the fixing plate 11 is formed. Is attached to.

The end plate 10, fixing plate 11 and band plate 12 are all manufactured and attached in advance in a factory or the like.

Both ends of the steel beam 3 are attached to bracket portions.
It is placed in the recess of 2b and has the end plate 10 at the tip.
Is attached to the side surface of the connection panel portion 1a.

Further, the fixing plate 11 is attached to the front end of the bracket portion 2b, the band plate 12 is fitted to the front end of the bracket portion 2b, and the front end portions of the upper end main bar 7a and the lower end bar 7b are fixed plate. A fixing nut 13 is screwed into the penetrating portion (not shown) of the eleventh portion. Then, concrete (not shown) is placed in the concave portion of the bracket portion 2b and in the upper portion thereof so that the steel beam 3, the upper end main bar 7a, the ribs 8, the width stop bar 9 and the end plate 10 are completely filled. .

A plurality of stud bolts 14 are provided on the inner side of the band plate 12 so that the stud bolts 14 can be completely integrated with the concrete placed in the recess of the bracket portion 2b.

Next, a method of constructing a joint construction method between a precast concrete column and a steel beam according to the first aspect of the present invention will be described step by step.

First, the PC columns 1 are erected at predetermined intervals so as to be self-supporting, the half PC columns 2 are placed on the column heads of the PC columns 1 (see FIG. 5), and the column main bars 4 of the through holes 5 are formed. The half-PC columns 2 are fixed on the PC columns 1 by penetrating the respective upper ends and carefully filling the through holes 5 with mortar or grout material (see FIG. 6).

Next, the steel beam 3 to which the end plate 10, the fixing plate 11 and the band plate 12 are attached is bridged between the PC columns 1 and 1, and both ends thereof are connected to the half PC column 2.
It is placed in the recess of the bracket portion 2b (see FIG. 7).

Next, the fixing plate 11 is attached to the bracket portion.
Attach the band plate 12 to the tip of the bracket portion 2b, and further attach the tip of the upper end beam main bar 7a and the lower end beam main bar 7b to the through hole (not shown) of the fixing plate 11. , The fixing nut 13 is screwed into the penetrating part (Fig. 7, 8
reference).

Next, necessary reinforcing reinforcing bars such as the width stop bar 9 are arranged. Then, a form (not shown) for pouring concrete is assembled on the upper side of the bracket 2b, and the end of the steel beam 3, the upper main reinforcement 7a, and the rib 8 are formed in the recess of the bracket 2b and on the upper side thereof. Then, concrete (not shown) is placed so that the width stop bar 9 and the end plate 10 are completely filled (see FIG. 1).

Example 2. 7 to 10 show a joint portion between a PC column and a steel beam under construction by a joint construction method between a precast concrete column and a steel beam according to claim 2 of the present invention, and as shown in Example 1. Even if the band plate 12 is not provided, if the fixing plate 11 is attached, the proof strength is substantially the same as that of the first embodiment.
Is omitted. Other configurations are substantially the same as those in the first embodiment.

Further, the construction method is also substantially the same as the construction order of the first embodiment except that the steps relating to the band plate 12 are omitted.

[0036]

The present invention is configured as described above, and according to the construction method for joining the PC column and the steel beam of claim 1 according to the present invention, it is formed in advance in a factory or on-site work place. A semi-PC column, which is pre-molded in a factory or the like and has a U-shaped bracket portion and a beam main bar connected to the steel beam, is installed on the column head of the PC column to connect the column and the beam. Since the parts are constructed, it is possible to secure high quality in terms of high rigidity and proof stress for the panel part (the joint part between the pillar and the beam).

Further, an end of a steel frame beam to which a band plate and a fixing plate are attached is mounted on the bracket portion of the half PC pillar, and the band plate is fitted to the tip end portion of the bracket portion. A fixing plate is attached to the fixing plate, and the end of the beam main bar protruding from the bracket portion of the half PC pillar is fixed to the fixing plate, and the half PC
By placing concrete so that the end of the steel beam is embedded in the bracket portion of the pillar, since the bracket portion and the steel beam are integrally joined, stress transmission from the steel beam to the bracket portion It is possible to construct a joint having a high toughness while being smoothly made to exhibit a high yield strength.

Further, since the steel beam can be supported only by mounting it on the bracket portion, the construction can be advanced by repeating the simple work without the need for supporting work at the time of construction, thus providing a highly safe joining construction method.

Further, P according to claim 2 of the present invention
According to the joint construction method of the C pillar and the steel frame beam, in addition to the above-mentioned effects, there is an effect that the elimination of the band plate enables the omission of parts and further labor saving.

[Brief description of drawings]

FIG. 1 is a perspective view showing a joint portion between a PC column and a steel beam under construction by a joint construction method of a PC column and a steel frame beam according to claim 1 of the present invention.

FIG. 2 is a plan view of a half PC pillar.

FIG. 3 is a side view of a half PC pillar.

FIG. 4 is a vertical sectional view of a half PC pillar.

FIG. 5 is a side view showing one step of a construction method.

FIG. 6 is a side view showing one step of a construction method.

FIG. 7 is a side view showing one step of a construction method.

FIG. 8 is a side view showing one step of a construction method.

FIG. 9 is a perspective view showing a joint portion between the PC column and the steel beam under construction by the joint construction method of the PC column and the steel beam according to the second aspect of the present invention.

10 is a plan view of a joint portion between the PC column and the steel frame beam shown in FIG. 9. FIG.

11 is a side view of a joint portion between the PC column and the steel beam shown in FIG. 8. FIG.

[Explanation of symbols] 1 ... PC column (precast concrete column) 2 ... Half PC
Column 2 (semi-precast concrete column), 3 ... Steel beam,
4 ... Column main muscle, 5 ... Through hole, 6 ... Rib bar (hoop muscle), 7a ...
Upper beam main bar, 7b ... Lower beam main bar, 8 ... Rib bar (Stirrup bar, 9 ... Width stop bar, 10 ... End plate, 11 ... Fixing plate, 12 ... Band plate, 13 ... Fixing nut, 14 ... Stud bolt.

Claims (2)

[Claims] 1. A method of joining a precast concrete column and a steel beam, comprising: a semi-precast concrete structure formed in a U shape so that an end of the steel beam can be placed on a column head of the precast concrete column. A bracket part and a semi-precast concrete column comprising a plurality of beam main bars connected to the steel beam are installed, and then a band plate fitted to the end part of the bracket part at the end part, An end portion of the steel beam to which a fixing plate to which the beam main bar is fixed is attached is mounted on a bracket portion of the semi-precast concrete column, and then the band plate is fitted to a tip portion of the bracket portion. Then, the beam main bars are fixed to the fixing plate, and concrete is placed inside and above the U-shape of the bracket portion to form the bracket portion. A method of joining precast concrete columns to steel beams, characterized by constructing a joint between steel beams and steel beams. 2. A method of joining a precast concrete column and a steel beam, comprising: a semi-precast concrete structure formed in a U shape so that an end of the steel beam can be placed on a column head of the precast concrete column. A semi-precast concrete column including a bracket portion and a plurality of beam main bars connected to the steel beam is installed, and then the steel frame is attached to the end with a fixing plate to which the beam main bar is fixed. The end of the beam is mounted on the bracket part of the semi-precast concrete column, then the beam main bar is fixed to the fixing plate, and concrete is placed inside the U-shape of the bracket part and the upper part thereof. Then, the joint structure between the precast concrete column and the steel beam is characterized by constructing a joint between the bracket part and the steel beam.