JP2001123534A - Precast composite beam structure - Google Patents

Abstract

(57) [Problem] To provide an inexpensive precast composite beam structure while ensuring the integrity of a concrete beam and slab concrete. SOLUTION: A steel pipe concrete column in which concrete is filled inside a steel pipe is connected to each other, and an end portion of the connection portion with the column is formed of a steel-frame concrete structure in which an H-shaped steel is disposed, and a central portion is formed of a reinforced concrete. In the structure of the precast composite beam made of precast concrete, the reinforcing steel of the reinforced concrete is fixed to the flange portion 7 of the H-shaped steel 14, and the beam main bar one step bar 3 extending in the axial direction of the precast composite beam 1; A second step 4 of the beam main reinforcement disposed inside the flange 7 of the section steel 14, and the second step of the beam main reinforcement near the stud 10 fixed inside the flange 7 of the H-section steel 14. A plurality of strips in which the reinforcing bars 4 are arranged, and the pitch of the portion where the precast composite beam 1 is switched from the reinforced concrete structure to the steel frame concrete structure is finer than the pitch of the other portions. And a ramp 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in the structure of a precast composite beam of a structure.

[0002]

2. Description of the Related Art Conventionally, in the construction of a concrete building, columns are made of steel reinforced concrete (SR) for the purpose of simplifying a beam-column joint and increasing the degree of freedom in design.
C), and a composite structure is adopted in which a composite beam is used as a beam by using a composite beam having different structures at an end portion and a central portion and combining these beams.

For example, the concrete beam 5 described in Japanese Patent No. 2629503 shown in FIGS. 16 and 17 has a PC beam 53 and a main reinforcing bar 56 arranged inside a concrete beam 51 and pre-stressed into a precast concrete beam 5.
1 and the steel pipe concrete column 52 are gusseted plates 6
2 and a web of the bracket 54, and a structure assembled by connecting the diaphragm 55 and the bracket 54.

In this structure, since the top end of the bracket 54 (H-shaped steel) provided at the end of the concrete beam 51 is continuously provided on the top end surface of the concrete beam 51, the flange of the bracket 54 is connected to the slab concrete. It is difficult to secure the adhesion strength with the studs, and studs are implanted at the top of the flange to ensure the integrity.

[0005] Japanese Patent Application Laid-Open No. 10-96294 shown in FIG.
No. 74 is the beam of precast concrete.
A steel H-shaped steel 71 is embedded in the end of the H-shaped steel 71, and a main bar 72 is arranged inside a flange of the H-shaped bar 71, and a hoop bar 73 is wound around the outside of the flange. H-beam 71 at the end of the beam
Is joined to a concrete-filled steel pipe column 76, and then the precast concrete beam 74 and the concrete-filled steel pipe column 7
The gap between 6 and 6 is formed by casting concrete on site simultaneously with the casting of the slab to form an integrated column-beam joint structure. In this method, the main bar 72 of the beam and the flange of the H-shaped steel 71 are not welded, and the required length of the H-shaped steel 71 needs to be increased in order to transmit stress only by adhesion of concrete inside the flange, It is expensive in terms of cost.

It is an object of the present invention to provide a precast composite beam structure that solves these problems.

[0007]

According to a first aspect of the present invention, a steel pipe-concrete column in which concrete is filled in a steel pipe is connected to each other, and an end portion of the connection with the column is provided with an H-shaped steel. In the structure of a precast composite beam made of precast concrete made of reinforced concrete, the central part of which is made of reinforced concrete, the reinforcing steel of the reinforced concrete is
A beam rebar one-step rebar fixed in the flange portion of the H-beam and extending in the axial direction of the precast composite beam; a beam rebar two-step rebar arranged inside the H-beam flange; The stud is fixed to the inside of the flange portion, and the stap is arranged such that the pitch of a portion where the precast composite beam is switched from the reinforced concrete structure to the steel frame concrete structure is smaller than the pitch of the other portions.

According to a second aspect of the present invention, in the first aspect, the upper portion of the stirrup of the precast composite beam projects from the precast concrete and is cast together with the slab at the time of casting the slab concrete.

[0009]

According to the first aspect of the present invention, there is provided a precast composite beam structure formed of precast concrete for connecting between steel pipe concrete columns in which concrete is filled in a steel pipe. H at the joint
It is made of steel concrete with section steel, and the center is reinforced concrete.

[0010] The rebar constituting the central portion is composed of a beam main bar first step bar, a beam main bar second step bar, and a stap, and the beam main bar first step bar is fixed to the flange portion of the H-shaped steel, and the axial direction of the precast composite beam. , And the beam main bar two-step bar is located near the stud, and is connected to the H-section steel through concrete.

[0011] By fixing the beam main reinforcement first step and the flange portion of the H-section steel, the force acting on the beam main reinforcement first step can be smoothly transmitted to the column through the flange section, and by fixing to the H section steel. , The required length of the H-section steel can be shortened, and the cost can be reduced.

Further, the stud is mounted inside the flange portion of the H-section steel, and the two-step reinforcing bar of the main beam is disposed near the stud, so that the force acting on the second step of the main beam of the beam is smoothly transferred from the concrete via the stud. In this case, the beam can be transmitted to the flange portion, and the beam can be reduced as compared with the case where the stud is mounted outside the flange portion.

Further, the pitch of the stirrup provided so as to surround the first reinforcement of the beam main reinforcement is different between the central portion of the reinforced concrete structure and the region where the structure changes from the reinforced concrete structure to the steel frame concrete structure. Finer than the pitch in the center.

With such a configuration, even when a large shear force acts on the composite beam, the force can be smoothly transmitted in the structural change region.

With the above structure, the force can be smoothly transmitted from the precast composite beam to the column, and the proof stress and rigidity in the structural change region can be effectively increased. In addition, the composite beam can be made lighter by reducing the beam width. In other words, a large indoor space can be secured.

In the second invention, the upper part of the stirrup of the precast composite beam protrudes from the precast concrete and is integrated with the slab when the slab concrete is cast, so that the integrity of the slab and the composite beam is ensured. be able to.

[0017]

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

FIGS. 1 to 5 show the configuration of this embodiment.

The main part of the building is constructed by connecting columns 2 erected in the vertical direction and precast composite beams 1 which are bridged between the columns 2 and serve as foundation members for forming a floor. Is done.

The column 2 is made using a concrete-filled steel pipe formed by filling a concrete 2a into a steel pipe 2b. Two diaphragms 12 are attached to the column 2 at a position where the precast composite beam 1 is joined so as to sandwich the precast composite beam 1 from above and below in a direction substantially perpendicular to the axis of the column 2.

The steel pipes 2b are respectively butted and connected via the diaphragms 12, and function as a form into which the filled concrete 2a is poured.

Further, a gusset plate 6 is arranged in the vicinity of the central axis of the precast composite beam between the two diaphragms 12, and this gusset plate 6 is abutted on the surface of the column 2 and is connected thereto.

The center of the diaphragm 12 is provided with a casting hole 17 and an air vent 8 for allowing the filled concrete 2a to spread throughout the column 2 without any gap.

The gusset plate 6 is provided with holes for bolts used for connection with the precast composite beam 1 in the vertical direction.
Rows are perforated.

The precast composite beam 1 to be connected to the column 2 is manufactured in advance at a factory or a construction site.

The structure of the precast composite beam 1 will be described in detail. An H-section steel 14 abutting against the column 2 is provided at both ends of the precast composite beam 1.
Are abutted against the two diaphragms 12, respectively.
It comprises a single flange 7 and a gusset plate 6 and a web 8 to be bolted. Two rows of holes are formed in the web 8 in the vertical direction so as to be bolted to the gusset plate 6 of the column 2.

A plurality of first beam reinforcing bars 3 are arranged on the upper flange 7 so as to be in contact with the lower surface and the lower flange 7 is in contact with the lower surface so as to be stretched over H-shaped steels 14 provided at both ends. . Beam main bar first step 3 is H-shaped steel 14 flange 7
Flared at the welding portion 11 and fixed.

The reason that the outer step 3 of the beam main reinforcement is extended to the vicinity of the gusset plate 6 is that it also serves as an additional reinforcement of the later-described stirrup 5, and is not necessary for strength. Absent.

A plurality of square stirrups 5 are arranged in the axial direction so as to surround the outer periphery of the upper and lower beam main reinforcing bars 3, and are arranged near the end of the gusset plate 6. The pitch of the stirrups 5 is such that the pitch of the stirrups 5 located on the outer peripheral portion of the H-section steel 14 is finer than the pitches of other positions.

Studs 10 are implanted inside the upper and lower flanges 7 of the H-section steel 14.

The beam main bar two-step bar 4 is made of concrete H-beam 1 made of concrete cast inside the upper and lower flanges 7 of H-beam 14.
4 is fixed inside. That is, the beam main bar two-step bar 4 has a length that is hung over the H-shaped steel 14 located at the left and right ends of the precast composite beam 1, and its shape has a hoop shape, and is interposed between concrete. To the inside of the right and left end flanges 7 of the H-section steel 14.

The reinforcing bars of the precast composite beam 1 are thus provided, and then a formwork is installed, and concrete is poured into the formwork to complete the precast composite beam 1. At this time, the concrete is cast so as to leave the upper part of the stapler 5 and to be driven in the axial direction over the entire beam main bar two-step bar 4 (so that the stirrup 5 near the end remains without touching the concrete). The mold is formed as is done in.

Next, a method of connecting the precast composite beam 1 and the column 2 will be described with reference to FIGS.

In FIG. 6, a steel pipe 2 b ′ already provided as the pillar 2 is used.
Another steel pipe 2b is installed at the upper end of the steel pipe, and fixed with a joint bolt or the like. At this time, the gusset plate 6 and the diaphragm 12 have already been assembled to the newly installed steel pipe 2b.

7 and 8, a precast composite beam 1 previously manufactured at a factory or the like is connected to a newly installed steel pipe 2b. At this time, the web 8 and the gusset plate 6 are fastened by bolts 9 penetrating holes provided in the web 8 of the precast composite beam 1 and the gusset plate 6 of the column 2. Furthermore, the flange 7 abuts against the diaphragm 12 and is connected, for example, by welding.

In FIG. 9, a formwork is assembled on the end of the precast composite beam 1 and the column 2, and the precast floor slab 16 is installed between the precast concrete.

In FIGS. 10 and 11, a reinforcing bar is provided on the floor slab.

In FIG. 12, post-cast concrete 13 is poured into the end of the precast composite beam 1 and the floor slab. At this time, concrete is not cast at the time of manufacturing the floor slab and the precast composite beam, and the upper portion of the stirrup 5 exposed from the precast composite beam is simultaneously cast at the concrete.

Referring to FIG. 15, a column 2 is formed by filling a concrete 2a into a steel pipe 2b, and a series of operations is completed.

By repeating the above operation,
A desired number of floors can be formed on the building.

As described above, in the precast composite beam of the present invention, the force acting on the main beam first reinforcement 3 is obtained by joining the main beam first reinforcement 3 to the flange 7 of the H-section steel 14 by flare welding. Can be smoothly transmitted to the column 2 through the flange 7, and by welding directly to the H-shaped steel 14, the length of the H-shaped steel 14 can be shortened and the beam can be reduced.

A stud 10 is attached to the inside of the flange portion 7 of the H-section steel 14, so that the force acting on the second main beam 4 can be smoothly transmitted from the concrete to the flange portion 7 via the stud 10. In addition, the beam can be made smaller than when the stud 10 is attached to the outside of the flange portion 7.

Further, the stirrup 5 provided on the outer periphery of the beam main reinforcement 1 step has a different pitch in the central portion of the reinforced concrete structure and in the region where the reinforced concrete structure changes to the steel frame concrete structure. Is finer than the central pitch, so that even when a large shear force acts on the composite beam 1, the force can be smoothly transmitted in the structural change region.

With the above configuration, the precast composite beam 1
, The force can be smoothly transmitted to the column 2, the proof stress and rigidity in the structural change region can be effectively increased, and the reduced beam width allows the composite beam to be lightened and a wide indoor space to be secured.

Further, when the upper stirrup of the precast composite beam is concretely cast simultaneously with the floor slab when the floor slab is cast into concrete, it is possible to ensure the integrity of the floor slab and the precast composite beam.

[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 BB in FIG.

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

FIG. 4 is a sectional view taken along the line DD in FIG. 1;

FIG. 5 is a sectional view taken along the line EE of FIG. 1;

FIG. 6 is a sectional view showing a construction process (before installing a precast composite beam).

FIG. 7 is a cross-sectional view showing a construction process (in a state where a precast composite beam is installed).

FIG. 8 is a cross-sectional view showing the same building process (precast composite beam joining completed).

FIG. 9 is a cross-sectional view similarly showing a construction process (a precast composite beam end form setting state).

FIG. 10 is a sectional view taken along the line FF of FIG. 9;

11 is a cross-sectional view of FIG. 9 taken along the line GG.

FIG. 12 is a cross-sectional view showing the same building process (post-cast concrete precast composite beam casting).

FIG. 13 is a sectional view taken along the line HH of FIG. 12;

FIG. 14 is a cross-sectional view taken along the line II of FIG. 12;

FIG. 15 is a cross-sectional view showing a building process (pillar-filled concrete filling state).

FIG. 16 is a diagram showing a joint between a concrete beam and a column in a conventional example.

FIG. 17 is a view showing an example of manufacturing a concrete beam.

FIG. 18 is a diagram showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Precast composite beam 2 Column 2a Filling concrete 2b Steel pipe 3 Beam main bar 1st step 4 Beam main bar 2nd step 5 Stirrup 6 Gusset plate 7 Flange 8 Web 9 Bolt 10 Stud 11 Welded part 12 Diaphragm 13 Post-cast concrete 14 H-shaped steel 15 Precast Concrete 16 Precast slab 17 Casting hole 18 Vent hole

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Shoji Umemura 1-6-8 Usaminami, Gifu-shi, Gifu Dainichi Feng Term Co., Ltd. F-term (reference) 2E163 FA12 FB02 FB07 FB21 FB36 FB42 FB43 FB44 FB46 FB47 FD02 FD11 FD23 FD25 FD32 FD33 FD34 FD36 FD37 FD42 FD43 FD44 FD46 FD54 FF12

Claims (2)

[Claims] 1. A steel pipe concrete column in which concrete is filled in a steel pipe, is joined to each other, and an end portion of the joint with the column is provided with an H-section steel, and a central portion is made of reinforced concrete. In the structure of the precast composite beam formed of the precast concrete, the reinforcing steel of the reinforced concrete is fixed to a flange portion of the H-shaped steel, and the beam main bar one step extending in the axial direction of the precast composite beam; A beam main reinforcement two-step reinforcement disposed inside the flange portion, wherein the beam main reinforcement two-step reinforcement is disposed near a stud fixed inside the flange portion of the H-shaped steel, and a reinforced concrete of a precast composite beam It is characterized by having a plurality of stalls that are arranged at a pitch that switches from building to steel concrete with a finer pitch than the pitch of other parts Structure of Rekyasuto composite beam. 2. The precast composite beam structure according to claim 1, wherein the upper portion of the stirrup of the precast composite beam projects from the precast concrete and is integrated with the slab when the slab concrete is cast.