JPH08232401A - Steel concrete synthetic beam structure - Google Patents

Abstract

PURPOSE: To provide a structure of a steel/concrete composite beam which is comparatively lightweight and has a similar strength to a ferro-concrete beam. CONSTITUTION: A plurality of projections 15, 16 are provided at a specific spacing in the longitudinal direction so as to form a truss mechanism on the interior wall surfaces of an upper flange plate 12 and lower flange plate 13 of a steel skeleton member 11 having a box-shaped cross-section. The steel skeleton member 11 is surrounded by an exterior concrete part and is filled internally with concrete, and the upper flange plate 12 is provided with an opening to serve for filling of concrete and establishing consolidation with the exterior concrete part. The projections 15 on the upper flange plate 12 and the ones 16 on the lower flange plate 13 are arranged opposingly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel-concrete composite beam structure, and more particularly to a structure of a beam member that constitutes a composite beam of steel and concrete.

[0002]

2. Description of the Related Art Heretofore, there has been no established technique for constructing a composite beam from steel frames and concrete. Generally, the beams in a building have a reinforced concrete structure, a steel frame reinforced concrete structure or a steel frame structure. Beams of reinforced concrete structure are generally formed with a rectangular cross section. A reinforced concrete beam with a rigid frame structure produces a tensile force downward at the center of the beam and upward at the end due to the bending action. Since concrete is vulnerable to tensile force, reinforcing bars are always placed where tensile force is generated, but main beams are also placed on the side that produces compressive force.

That is, in a reinforced concrete beam, main bars (upper bar) are arranged along each corner on the upper side, and main bars (lower bar) are arranged along each corner on the lower side. The stirrup bar (star wrap) so that the entire main bar is wound at a predetermined interval in the longitudinal direction of the
Are arranged to counter the shearing force.

On the other hand, as steel frame beams, shaped steel beams, plate beams, truss beams and the like are known. As the shaped steel beam, an I-shaped cross section or an H-shaped cross section that is advantageous for bending action is used. Further, the plate beam is formed by welding angle steel and steel plate, or steel plate and steel plate assembled by welding or rivets, and mainly has a cross-sectional shape that is advantageous for bending action and convenient for joining with columns. Shaped cross-sections are used, and sometimes box-shaped cross-sections are also used.

Further, the truss beam is a chord member corresponding to the flange portion of the plate beam and a web member (oblique member
Vertical material) is assembled using gusset plates, and is a parallel chord truss that is parallel to the upper and lower chord members. Angle steel is usually used for the chord and web members.

[0006]

As described above, the conventional beam used in the building has a reinforced concrete structure or a steel frame structure. However, the reinforced concrete beam has a high rigidity but a very large weight. However, there is a problem that the steel frame beam is light in weight but inferior in rigidity to the reinforced concrete beam.

An object of the present invention is to solve the above conventional problems, and to provide a structure of a steel-reinforced concrete composite beam which is relatively lightweight and has strength equivalent to that of a reinforced concrete beam. is there.

[0008]

The present invention is a steel-framed concrete composite beam structure, and is configured as follows in order to solve the above-mentioned technical problems. That is, the steel-concrete composite beam structure of the present invention has a box-shaped steel frame main body 11
And a plurality of protrusions 15 provided at predetermined intervals in the longitudinal direction of the flange plates 12 and 13 to form a truss mechanism on the inner wall surfaces of the upper flange plate 12 and the lower flange plate 13 of the steel frame body 11. , 16, an outer concrete portion 17 surrounding the outside of the steel frame body 11 having a box-shaped cross section, an inner concrete portion 18 filled in the steel frame body 11 having a box-shaped cross section, and an upper flange plate of the steel frame body 11. 12, and at least one opening 19 used for filling when forming the internal concrete portion 18, wherein each protrusion 15 of the upper flange plate 12 is the protrusion of the lower flange plate 13. It is characterized in that the parts 16 face each other. Here, characteristic components of the steel-concrete composite beam structure of the present invention will be described.

(Steel frame body) The steel frame body 11 has a box-shaped cross section. That is, the upper flange plate 12, the lower flange plate 13, and the opposite side plates 14 that mainly consist of an iron plate.
Are joined to each other by welding or the like. The upper and lower flange plates 12 and 13 resist tensile force against the bending moment acting on the beam, and the both side plates 14 function as shear reinforcing steel materials. Therefore, it is preferable that the both side plates 14 for shearing reinforcement are made of steel plates thinner than the upper and lower flange plates 12 and 13.

(Protrusions) A large number of protrusions 15 and 16 provided on the inner surfaces of the upper flange plate 12 and the lower flange plate 13, that is, the surfaces facing each other, at predetermined intervals in the longitudinal direction form a truss mechanism. For example, a channel material, an angle material or a stud bolt is used for the flange plates 12, 13
It can be fixed and used. These protrusions 1
It is also preferable that 5 and 16 are extended and formed in the direction orthogonal to the longitudinal direction of the steel frame main body 11.

(Opening) Upper flange plate 1 of steel frame body 11
2 has an opening 19 formed therein. Explaining the existence of the opening 19, the steel frame body 1 having a box-shaped cross section is provided to counter the compressive force against the bending moment exerted on the beam.
The outer periphery of 1 is surrounded by concrete and the inside is also filled with concrete. At this time, the above-mentioned opening 19 serves to integrate the outer concrete part 17 on the outer peripheral side of the steel frame body 11 and the inner concrete part 18 on the inner side, and at the same time, to fill the inside of the steel frame body 11 with concrete. Therefore, there may be a plurality of openings, and the shape and size thereof can be appropriately designed.

<Additional Structure in the Present Invention> The steel-framed concrete composite beam structure of the present invention is composed of the above-mentioned essential components, but is also established in the following specific cases. The additional component means that a part excluding the upper part of the external concrete part 17 surrounding the outside of the steel frame body 11 having a box-shaped cross section is formed of a half precast concrete body 17a, and the upper part of the external concrete part 17 and the above-mentioned The internal concrete portion 18 is characterized by being formed of cast-in-place concrete.

[0013]

According to the steel-concrete composite beam structure of the present invention, the upper and lower flange plates 12, 13 of the box-shaped steel frame body 11 oppose the tensile force acting on the upper and lower parts of the beam 10 and the side plates. 14 opposes the shear forces acting on this beam.

A large number of projections 15 and 16 are provided on the inner surfaces of the upper flange plate 12 and the lower flange plate 13 so as to be spaced apart in the longitudinal direction and face each other. Each part forms a truss mechanism by applying a compressive force to the internal concrete part 18 interposed between them.

As a result, this steel-concrete composite beam structure can reasonably transmit the force between the steel frame and the concrete, is lighter and cheaper than the reinforced concrete beam, and has the same strength. It

[0016]

EXAMPLES The steel-framed concrete composite beam structure of the present invention will be described in more detail with reference to the examples shown in the drawings. FIG. 1 shows a steel-concrete composite beam structure according to an embodiment of the present invention.

The steel-reinforced concrete composite beam 10 of this embodiment shown in FIG. 1 includes a steel-frame main body 11 having a box-shaped cross section. The steel frame body 11 is an upper flange plate 1 mainly composed of an iron plate.
2, the lower flange plate 13, and the opposite side plates 14 are joined to each other by welding or the like.

The upper and lower flange plates 12 and 13 resist the tensile force against the bending moment acting on the beam 10, and the both side plates 14 function as shear reinforcing steel materials. Therefore, the side plates 14 for shear reinforcement are made of steel plates thinner than the upper and lower flange plates 12 and 13.

The flange plate 1 is provided on the inner wall surfaces of the upper flange plate 12 and the lower flange plate 13 which constitute the steel frame body 11.
A large number of channel members 15 and 16 are provided by means such as welding, which extend in the width direction of 2 and 13 and are spaced at predetermined intervals in the longitudinal direction. Then, as shown in FIG. 3, each channel member 15 of the upper flange plate 12 has a lower flange plate 1
The three channel members 16 are arranged to face each other. Each of these channel members 15 and 16 functions as a protrusion for forming a truss mechanism.

The steel frame body 11 having a box-shaped cross section is surrounded by an outer concrete portion 17. This external concrete part 1
7, the part excluding the upper part is formed of a half precast concrete body 17a. The outer concrete portion 17b at the upper portion is formed of cast-in-place concrete as described later.

Concrete is also filled in the steel frame body 11 having a box-shaped cross section. This internal concrete part 1
8 is also made of cast-in-place concrete as described later. In this connection, the upper flange plate 12 of the steel frame body 11
A plurality of openings 19 are formed in the.

These openings 19 are used as filling ports when filling the inside of the steel frame body 11 with concrete, and are also used for ensuring the integrity with the external concrete portion 17.

As is apparent from FIG. 2, for example, a bolt or a short projection 20 having various shapes is provided on the lower surface of the lower flange portion 13 in order to improve the adhesion with the external concrete portion 17. It is also preferable that a bar member 21 such as a reinforcing bar is fixed to the tip end portions of these protrusions 20.

The steel-framed reinforced concrete composite beam 10 thus constructed can be formed as follows.
That is, after first forming the steel frame body 11 described above,
Outside the outer concrete part 17 except the upper part, U
Form in a letter shape. Up to this point, it can be formed in advance in a factory or the like.

A half beam semi-finished product in which the half precast concrete body 17a thus formed and the steel frame main body 11 having a box-shaped cross section are arranged and integrated therein is transported to a construction site and installed as a beam as shown in FIG. In the gap between the precast concrete floorboards 22 which is the position, the upper surface of the half precast concrete body 17a is installed so as to contact the lower surface of the precast concrete floorboard 22, and both ends thereof are used as columns (not shown) on both sides. connect.

As a result, the upper portion of the steel frame body 11 projecting from the half precast concrete body 17a slightly projects above the surface of the precast concrete floor plate 22. After that, concrete is filled from the opening 19 formed in the upper flange plate 12 to form the internal concrete portion 18, and concrete is also placed on the precast concrete floor plate 22 to form the floor portion.

As a result, the concrete 23 cast for forming the floor portion is filled in the gap between the both side plates 14 of the steel frame body 11 and the end portions of the precast concrete floor plate 22 and at the same time, on the steel frame body 11. The flange plate 12 is embedded to form the upper portion 17b of the outer concrete portion 17, whereby the steel-concrete composite beam 10 is completed.

According to the structure of the steel-reinforced concrete composite beam 10 as described above, the upper and lower flange portions 12 and 13 of the steel-frame main body 11 having a box-shaped cross section counteract the tensile force acting on the upper and lower portions of the beam, and Both side plates 14 oppose the shearing forces acting on this beam.

A large number of channel members 15 and 16 provided on the inner surfaces of the upper flange plate 12 and the lower flange plate 13 so as to be spaced from each other in the longitudinal direction and face each other are arranged in an oblique direction as shown in FIG. A pair of upper and lower channel members positioned at the above positions form a truss mechanism by applying a compressive force to the oblique region portion 24 of the internal concrete portion 18 interposed therebetween.

The channel members 15 and 16 may be installed in a minimum number and a space between them so that the truss mechanism is formed. It is appropriately designed from the length of 10, the required strength, and the like.

As a result, the steel-concrete composite beam 10 can reasonably transmit the force between the steel frame and the concrete, and is lighter and cheaper than the reinforced concrete beam, but has the same strength. It

In the steel-concrete composite beam 10 of the above-described embodiment, the channel material 1 is formed on the inner surfaces of the upper flange plate 12 and the lower flange plate 13 to form the truss mechanism.
5 and 16 are provided, the channel material may be replaced with an angle material or a stud bolt, or as shown in FIG. 4, the upper and lower flange plates may be integrally formed with the protruding portions 25 and 26. May be.

[0033]

As described above, according to the present invention,
Concrete is placed inside and outside the box-shaped steel frame body consisting of the upper flange plate and the lower flange plate to counter the tensile force, and the side plate to counter the shearing force, and the protrusions formed on the upper and lower flange plates. Since the truss mechanism is configured by the concrete portion in the meantime, it is possible to provide a structure of a steel-framed concrete composite beam that is relatively lightweight and has the same strength as a reinforced concrete beam.

[Brief description of drawings]

FIG. 1 is a perspective view showing a partially broken steel-framed concrete composite beam of the present invention.

FIG. 2 is a cross-sectional view showing the steel-concrete composite beam of the present invention installed in a structure.

FIG. 3 is a cross-sectional view showing the steel-framed concrete composite beam shown in FIG. 2 cut along the longitudinal direction thereof.

FIG. 4 is a sectional view similar to FIG. 3, showing a steel-framed concrete composite beam according to another embodiment of the present invention.

[Explanation of symbols]

 10 Steel-Concrete Composite Beam 11 Steel Frame Main Body 12 Upper Flange Plate 13 Lower Flange Plate 14 Side Plate 15 Channel Material 16 Channel Material 17 External Concrete Part 17a Half Precast Concrete Body 17b Upper Part of External Concrete Part 18 Internal Concrete Part 19 Opening Part 20 Projection Part 21 Bar material 22 Precast concrete floorboard 23 Concrete floor part 24 Internal compression part compression load part 25 Projection part 26 Projection part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Katsura Kobayashi Keiji Kobayashi 2-10-10 Fujimi, Chiyoda-ku, Tokyo Maeda Construction Industry Co., Ltd. (72) Yufumi Hirota 2--10-10 Fujimi, Chiyoda-ku, Tokyo Maeda Construction Co., Ltd. (72) Inventor Yasuji Maeda 2-10-10 Fujimi, Chiyoda-ku, Tokyo Maeda Construction Co., Ltd. (72) Yuzo Ichijo 2-1026 Fujimi, Chiyoda-ku, Tokyo Maeda Construction Co., Ltd. (72) Inventor Yoji Hosokawa 2-10-10 Fujimi, Chiyoda-ku, Tokyo Maeda Construction Co., Ltd. (72) Shinji Kato 2--10-10 Fujimi, Chiyoda-ku, Tokyo Maeda Construction Industry Co., Ltd.

Claims (2)

[Claims] 1. A steel frame main body having a box-shaped cross section, and a predetermined interval in the longitudinal direction of the flange plate to form a truss mechanism on the inner wall surfaces of the upper flange plate and the lower flange plate of the steel frame main body. A plurality of protrusions, an external concrete portion surrounding the outside of the steel frame body having a box-shaped cross section, an internal concrete portion filled in the steel frame body having a box-shaped cross section, and an upper flange plate of the steel frame body. And at least one opening used for filling when forming the internal concrete portion, and the protrusions of the upper flange plate are opposed to the protrusions of the lower flange plate, respectively. A steel-concrete composite beam structure characterized by the above. 2. A box-shaped cross section is formed of a half precast concrete body except for an upper portion of an outer concrete portion surrounding the outside of the steel frame body, and the upper portion of the outer concrete portion and the inner concrete portion are cast in situ. The steel-reinforced concrete composite beam structure according to claim 1, wherein