JP2000073448A - Connection method and structure for precast concrete beam and column - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a connection structure of a precast concrete beam and a steel frame column and save labor in a construction site. SOLUTION: A precast concrete beam 17 having a built-in end axial reinforcements 3 is constructed in advance and the precast concrete beam 17 is connected to a steel pipe 22 (steel frame column), in this connection method. The axial reinforcements 3 extended from the end of the precast concrete beam 17 are stretched to penetrate the steel pipe and fastened through nuts 11 and thereafter, post-cast concrete 10 is placed to surround the connection part of the precast concrete beam 17 and the steel pipe 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a structure for joining a precast concrete beam and a column of a building.

[0002]

2. Description of the Related Art In recent years, in order to save labor and shorten the construction period of high-rise buildings on site, precast concrete members are cast in advance at a factory or construction site as pillars and beams of the building, and precast concrete members are formed. Many precast methods are used to assemble components at the construction site.

[0003]

However, in the case where a steel column is used for a pillar of a building and a precast concrete member is used for a beam, the beam reinforcement is connected to the diaphragm by welding or the like, or the beam reinforcement is formed from the column surface. It must be joined at a fixed distance using mechanical joints, etc.The former requires time and effort in welding in a narrow space, the latter has a shorter precast concrete beam, There was a problem that the assembling work of the formwork was troublesome.

The present invention has been made in view of the above problems, and has as its object to simplify the structure for joining a precast concrete beam and a steel column and to save labor on site.

[0005]

Means for Solving the Problems The first invention is applied to a method of forming a precast concrete beam containing a main reinforcing bar in advance and joining the precast concrete beam and a steel column.

[0006] The main reinforcement extending from the end of the precast concrete beam is penetrated and fastened to the steel column, and after fastening the main reinforcement to the steel column, post-cast concrete surrounding the joint between the precast concrete beam and the steel column is poured. To do.

According to a second aspect of the present invention, in the first aspect, a steel pipe having a closed cross section is provided as a steel column, a hole is formed in the steel pipe so as to penetrate a main reinforcement, and after the main reinforcement is fastened to the steel pipe, concrete is placed inside the steel pipe. It was to be filled.

According to a third aspect, in the first or second aspect, there is provided a web plate projecting from an end of the precast concrete beam, and a gusset plate projecting from a steel column, and the web plate and the gusset plate are fastened to each other. To do.

According to a fourth aspect of the present invention, in any one of the first to third aspects of the present invention, an end main reinforcement inserted removably from both ends of the precast concrete beam via a sheath, and a central portion of the precast concrete beam. And a central main bar arranged so as to partially overlap the end main bar.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects of the invention, a PC steel material for imparting tension to the precast concrete beam is incorporated.

[0011]

The first invention simplifies the structure for joining the precast concrete beam and the steel column by penetrating the main reinforcement extending from the end of the precast concrete beam into the steel column and fastening the same. compared to,
It is not necessary to weld the reinforcing bar in a narrow space, or it is possible to reduce the work of assembling the reinforcing bar and the formwork in the post-punched portion, thereby saving on-site work and shortening the construction period.

[0012] In the second invention, the main reinforcement is fixed to the steel pipe via concrete filled inside the steel pipe.

[0013] The structure of forming a hole through the main pipe in the steel pipe eliminates the need for a step of welding a diaphragm or the like which has been conventionally used to join beams of H-section steel, and saves labor for processing and assembling steel frames. To be peeled off.

Further, by filling the inside of the steel pipe with concrete, the steel material and the fireproof coating material of the steel column are reduced, and there is no need to cast concrete around the steel column.

In the third aspect of the present invention, the precast concrete beam is fastened to the steel column via the web plate and the gusset plate, so that the shear load acting on the joint between the beam and the column is mainly caused by the fastening portion between the gusset plate and the web plate. Supported, the bending load is mainly supported by the main reinforcement, and sufficient rigidity is secured.

In the fourth aspect of the present invention, when joining the precast concrete beam and the steel column, the work efficiency is improved by pulling out the main end bar from the end of the precast concrete beam.

By fixing the end main muscle to the sheath,
The end main bar and the center main bar constitute a lap joint inside the precast concrete beam, and the structure is simplified by eliminating the need for a mechanical joint.

According to the fifth aspect of the present invention, the prestressed concrete beam is given a prestress by each PC steel material, so that the beam can be increased in strength and rigidity, and even if the span is long, the deflection can be suppressed to a small value. Vibration can be suppressed.

[0019]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in FIG. 1, the main structure of the building is composed of pillars 2 extending upward and beams 1 spanning between the pillars 2.

The column 2 includes a steel tube 22 as a steel column having a square closed cross section, and a concrete column 21 formed by filling concrete inside the steel tube 22. Note that an H-section steel may be used as the steel column.

The beam 1 is provided with a precast concrete beam 15 formed in advance by casting at a factory or a construction site, and the end main reinforcing bar 3 and the central main reinforcing bar 8 are used as reinforcing bars disposed inside the precast concrete beam 17. Stirrups (stirrups) 9 and the like are provided.

At both ends of the precast concrete beam 17, four end main reinforcements 3 are arranged, and between each end main reinforcement 3, five central main reinforcements 8 are arranged. Each end main reinforcing bar 3 is provided with an annular sheath 7 from both ends of the precast concrete beam 17.
Is inserted so that it can be pulled out. Each central main bar 8 is arranged so that both ends thereof overlap the main bar 3. Sheath 7
The end main reinforcing bar 3 and the central main reinforcing bar 8 form a joint by filling the grout material and connecting the two with each other.

Each stirrup 9 is formed in a square frame shape.
The upper part protrudes from the upper surface of the precast concrete beam 17. At the end of the precast concrete beam 17, eight pairs of stirrups 9 are arranged so as to overlap each other. Each end main reinforcement 3 is arranged inside a corner of each stap 9.

The web plates 5 projecting from both ends of the precast concrete beam 17 are provided. A part of the web plate 5 made of a square iron plate is embedded and fixed in a precast concrete beam 17. On the other hand, a gusset plate 4 protruding from the side surface of the steel pipe 22 is provided. When assembling the beam 1 to the column 2, the web plate 5 and the gusset plate 4 are fastened to each other via five bolts 6.

As the gist of the present invention, when assembling the beam 1 to the column 2, each end main reinforcing bar 3 extending from the precast concrete beam 17 is passed through the steel pipe 22 and fastened. A hole is formed in the steel pipe 22 so as to penetrate each end main reinforcing bar 3.

A thread portion is formed on the outer periphery of each end main reinforcing bar 3, and the end main reinforcing bar 3 is fastened to the steel pipe 22 via two nuts 11 screwed to the screw portions. Note that the end main reinforcement 3 may be fastened to the steel pipe 22 via another fixing tool instead of the nut 11.

After assembling the beam 1 to the column 2, a post-cast concrete portion 10 surrounding the beam 1 and the column 2 and forming a slab is cast through a formwork.

In placing the post-cast concrete portion 10, the end main reinforcement 3 and the central main reinforcement 8 are arranged above the precast concrete beam 17 in the same manner as inside the precast concrete beam 17. Each end main reinforcing bar 3 penetrates the column 2 and is fastened to the steel pipe 22 via two nuts 11 screwed into screw portions formed on the outer periphery thereof.

The shear load acting on the joint between the beam 1 and the column 2 is mainly supported by the fastening portion of the gusset plate 4 and the web plate 5, and the bending load is mainly supported by the main bar 3 at each end. You. The precast concrete beam 17 suppresses the occurrence of vibration disturbance even when the span is longer than the case where the beam is made of H-shaped steel, and can be applied to an apartment house.

A steel column 22 having a closed section is provided as a steel column, and concrete is filled after the end main reinforcement 3 is fastened to the steel tube 22, so that the concrete column 21 formed in the steel tube 22 locally buckles the steel tube 22. And improve rigidity, proof stress and structural performance. The steel material of the steel frame and the refractory coating material can be reduced, and there is no need to cast concrete around the steel column, so that labor on site work can be saved.

Next, the construction process will be described in order with reference to FIGS.

As shown in FIG. 5, a new steel pipe 22 is added to the upper end of the steel pipe 22 already built as the column 2, and temporarily fixed via a plurality of joint bolts 15.

Subsequently, as shown in FIG. 6, the beam 1 is connected to the newly added steel pipe 22. At this time, first, the web plate 5 and the gusset plate 4 are fastened via the bolts 6. Then, the joint bolt 6 is tightened and fixed while the newly added steel pipe 22 is held at a predetermined position.

Subsequently, as shown in FIG. 7, the central main bar 8 in the sheath 7 is pulled out, penetrated through the steel pipe 22, and fastened to the steel pipe 22 via the nut 11. Then, the end main reinforcement 3 and the central main reinforcement 8 are arranged above the precast concrete beam 17, and each end main reinforcement 3 is passed through the steel pipe 22 and fastened to the steel pipe 22 via the nut 11.

Thus, the precast concrete beam 17
The structure that joins the steel pipe 22 with the steel pipe 22 is simplified, and compared to the conventional method, welding of the reinforcing bar in a narrow space is not required, or the assembling work of the reinforcing bar and the formwork in the after-cast portion can be reduced,
Labor saving on-site work is achieved.

Further, the structure in which the hole for penetrating the end main reinforcement 3 is formed in the steel pipe 22 eliminates the need for a step of welding a diaphragm or the like which has been conventionally used for joining an H-beam to the steel pipe. Labor saving in processing and assembling work.

Subsequently, as shown in FIG. 8, a grout material is filled in the sheath 7, and the sheath 7 and the central main bar 8 are fixed.
Then, the column joint is welded.

By fixing the end main reinforcing bar 3 to the sheath 7 in this way, the end main reinforcing bar 3 and the central main reinforcing bar 8 constitute a lap joint in the precast concrete beam 17, and the structure is simplified by eliminating the need for a mechanical joint. .

Subsequently, as shown in FIG. 9, a post-cast concrete portion 10 surrounding the beam 1 and the column 2 and forming a slab is cast through a formwork.

Subsequently, as shown in FIG. 10, concrete is filled in the steel pipe 22 to form a concrete column 21. The end main reinforcement 3 is fixed to the steel pipe 22 via concrete filled inside the steel pipe 22.

Each floor of the building is constructed by sequentially performing the above steps.

Next, the embodiment shown in FIGS. 11 to 14 will be described. Note that parts corresponding to those in FIGS. 1 to 4 are denoted by the same reference numerals.

The precast concrete beam 17 incorporates two PC steel members 12 for applying tension. A pair of fixing plates 1 at both ends of the precast concrete beam 17
3 are embedded, and both ends of each PC steel material 12 penetrate each fixing plate 13 and are fastened via nuts 14 screwed to the outer periphery thereof.

In this case, the precast concrete beam 1
7 is given a pre-stress by each PC steel material 12, whereby the beam 1 has an increased strength and rigidity, and even if its span becomes longer, its bending is kept small.
Floor vibration can be suppressed.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention, and is a cross-sectional view taken along line AA of FIG.

FIG. 2 is a sectional view taken along the line DD of FIG. 1;

FIG. 3 is a sectional view taken along the line BB of FIG. 1;

FIG. 4 is a sectional view taken along the line CC of FIG. 1;

FIG. 5 is a sectional view showing a construction process.

FIG. 6 is a sectional view showing a construction process.

FIG. 7 is a sectional view showing a construction process.

FIG. 8 is a sectional view showing a construction process.

FIG. 9 is a cross-sectional view showing a construction process.

FIG. 10 is a cross-sectional view showing the same building process.

FIG. 11 shows another embodiment, and is a cross-sectional view taken along the line EE of FIG. 2;

FIG. 12 is a sectional view taken along the line HH in FIG. 1;

FIG. 13 is a sectional view taken along the line FF of FIG. 1;

FIG. 14 is a sectional view taken along the line GG of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Beam 2 Column 3 End main reinforcement 4 Gusset plate 5 Web plate 6 Nut 7 Sheath 8 Central main reinforcement 9 Stirrup 10 Post-cast concrete 11 Nut 12 PC steel material 17 Precast concrete beam 21 Concrete column 22 Steel pipe

Claims (5)

[Claims] 1. A precast concrete beam containing a main reinforcing bar is formed in advance, and a main reinforcing bar extending from an end of the precast concrete beam is penetrated through a steel column and fastened. After the main reinforcing bar is fastened to the steel column, the precast concrete beam is fastened. A method for joining a precast concrete beam and a column, comprising casting a post-cast concrete surrounding a joint between the beam and the steel column. 2. A steel pipe having a closed section as the steel column, wherein a hole is formed in the steel pipe so as to penetrate the main reinforcement, and after the main reinforcement is fastened to the steel pipe, concrete is filled inside the steel pipe. The method of joining precast concrete beams and columns according to claim 1. 3. The web plate protruding from an end of the precast concrete beam, and the gusset plate protruding from the steel column, wherein the web plate and the gusset plate are fastened. 3. The method for joining a precast concrete beam and a column according to 1 or 2. 4. An end main reinforcing bar inserted removably from both ends of the precast concrete beam via the sheath, and a central portion of the precast concrete beam is disposed so as to partially overlap the end main reinforcing bar. The joint structure between a precast concrete beam and a column according to any one of claims 1 to 3, further comprising a central main reinforcing bar. 5. The precast concrete beam has a built-in PC steel material for imparting tension thereto.
5. The joint structure between a precast concrete beam and a column according to any one of items 1 to 4.