JP2747678B2 - Composite beam - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite beam used for an architectural structure in which a pillar is made of S (steel frame) or SRC (steel reinforced concrete).

[0002]

2. Description of the Related Art The rigidity of a beam end greatly affects the horizontal rigidity of a building. For this reason, as one of the rational means to increase the rigidity of the beam end, a composite beam in which the end of the beam is made of SRC and the center of the beam is made of S or a composite beam of steel frame and floor concrete, so-called "End SRC beam" has been proposed, leading to several examples of construction.

[0003] The end SRC beam can reduce the amount of steel frame used and increase the rigidity of the beam end compared to the case where the thickness of the upper and lower flanges and the beam structure of the I-shaped section steel beam are increased to increase the rigidity of the beam end. It is very effective in controlling frame deformation and preventing floor vibration in spanned buildings, but there is room for improvement in the following points.

[0004] That is, in order to increase the rigidity of the beam end, it is advantageous to arrange a steel material having a much higher Young's modulus than concrete as far as possible. Since the end of the beam has a structure in which the outer periphery of the I-shaped beam steel frame is surrounded by concrete, steel with a large Young's modulus is located inside the concrete, and moreover, reinforcement is provided on the outer periphery of the beam steel frame. It is necessary to secure the concrete covering thickness for the set beam reinforcement (upper and lower beam main reinforcements and stirrups wrapped around them). From the upper and lower concrete surfaces of the end SRC beam to the upper and lower flanges of the beam steel The width of the beam is widened, and the vertical width of the steel beam (the vertical width of steel only) is smaller than the beam. Therefore, in these respects, it can be said that the rigidity of the steel material is not sufficiently utilized.

[0005] In recent years, centrifugally formed square steel tube concrete has begun to be used as a column material having high yield strength and high rigidity. Centrifugally formed square-tube steel concrete has a much higher Young's modulus than ordinary concrete because the inner concrete is centrifugally formed, and the concrete strength is determined by the centrifugal molding method. It can be used even for slump-zero concrete that cannot be cast by the usual molding method that only involves pouring.
High-strength concrete of about 00 to 1000 kg / cm ² can be realized.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been made in consideration of the above points, and an object of the present invention is to use a centrifugally formed square steel pipe concrete as a beam material to reduce the rigidity of the steel material. It is an object of the present invention to provide a composite beam capable of fully utilizing and securing rigidity of a beam end portion, while reducing costs by reducing the amount of steel used and improving lifting efficiency by reducing weight.

[0007]

The technical measures taken by the present invention to solve the above-mentioned problems are as follows.
That is, the composite beam according to the invention, the ends of the beam cross section Vertical
The thickness of the upper and lower plates is rectangular and the thickness of the left and right plates is
Larger square steel pipe and the square steel pipe as a formwork
It is made of centrifugally formed square steel tube concrete including centrifugally formed concrete, and is characterized in that the center of the beam is an S beam or a composite beam of steel frame and floor concrete.

[0008]

According to the above construction, since the concrete at the end of the beam is a concrete formed by centrifugal molding, a concrete having a Young's modulus much higher than that of ordinary concrete and high strength can be realized. In addition, since a steel material (steel pipe) having a higher Young's modulus than concrete is located outside the concrete, the rigidity of the steel material is sufficiently utilized, and the rigidity of the beam end can be significantly increased. Obedience
Thus, the amount of steel used can be reduced. In particular, concrete
A steel material (steel pipe) located outside of the heat exchanger
And the thickness of the upper and lower plates is greater than the thickness of the left and right plates.
Square steel pipe, which effectively increases bending rigidity.
Can reduce the amount of steel used.
You.

[0009]

1 to 3 show a building using a composite beam according to the present invention. Reference numeral 1 denotes an S-shaped column, which is made of a square steel pipe. A is a composite beam erected between the columns 1 and 1. As shown in FIG. 4, the composite beam A is made of centrifugally formed square steel tube concrete 2 at the end of the beam, and the central portion of the beam is made up of an I-shaped section steel frame 3 and floor concrete 4 as shown in FIG.
And the composite beam 5. Reference numeral 6 denotes a shear connector for integrating the steel frame 3 and the floor concrete 4. 7 shown in FIGS. 2 and 3 is a deck plate.

[0010] The centrifugally formed square steel pipe concrete 2 is shown in FIG.
As shown in FIG. 5, a rectangular steel pipe 2a having a vertically long rectangular cross section and having a thickness of the upper plate and the lower plate larger than a thickness of the left and right side plates.
And a concrete 2b formed by centrifugal molding using the square steel pipe 2a as a mold, and an end plate 2c made of a steel plate is welded to at least an end portion on the beam center portion side. Reference numeral 2d denotes a cavity formed by centrifugal molding. After completion of the molding, the cavity 2d may be filled with concrete, high-strength mortar, or the like. 2e is a joining plate welded to the end plate 2c. 800 to 100 for concrete 2b
High-strength concrete of about 0 kg / cm ² is used.

Centrifugally formed square steel pipe concrete 2 and steel frame 3
Means that the upper and lower flanges 3a, 3b of the steel frame 3 are welded to the end plate 2c, and the vertical web 3c of the steel frame 3 and the joining plate 2e are fastened by rivets or bolts and nuts 8
… Are integrated by connecting with each other. The square steel pipe 2a of the centrifugally formed square steel pipe concrete 2 and the column 1 are connected by welding.

The construction procedure of the building shown in FIGS.
It is as follows. The centrifugally formed square steel tube concrete 2 and the column 1 are welded in advance at a factory. The column 1 with the centrifugally formed rectangular steel pipe concrete 2 is carried into the site, suspended using a hoist, and erected at a predetermined position as shown in FIG.

After that, the steel frame 3 is moved to the pillars 1 by using a hoist.
As shown in FIG. 3 (b), the end of the steel frame 3 is connected to the centrifugally formed square steel tubular concrete 2, 2 by welding and fasteners 8.

In this state, the deck plate 7 is laid,
Floor reinforcement (not shown) is performed thereon, and the floor concrete 4 is poured.

FIG. 6 shows a state in which a composite beam A is erected on a pillar 1 made of SRC. 1a is a column steel frame, 1b is a column main bar, and 1c is a column concrete. The square steel pipe 2a of the centrifugally formed square steel pipe concrete 2 is welded to the column steel frame 1a. The other configuration is the same as that of the previous embodiment, and the description is omitted.

In each of the above embodiments, the central portion of the composite beam A is a composite beam of the S structure and the floor concrete 4, but in the present invention, the central portion of the beam is an S structure (pure). Steel frame)
It is also possible to implement as.

[0017]

As described above, according to the present invention, since the beam ends are made of centrifugally formed square steel tube concrete, the Young's modulus of the concrete at the beam ends is much higher than that of ordinary concrete, and moreover, compared to concrete. Since the steel material (steel pipe) with a higher Young's modulus is located on the outermost side, the rigidity of the steel material can be fully utilized, and the centrifugal molding can realize high-strength concrete. The rigidity can be significantly increased. In particular, Concree
The steel material (steel pipe) located outside the
And the thickness of the upper and lower plates is greater than the thickness of the left and right plates.
Effectively increased bending rigidity due to large square steel pipe
Can be Therefore, while securing the rigidity of the beam end, it is possible to reduce the cost by reducing the amount of steel used and to improve the lifting work efficiency by reducing the weight.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view showing an example of a composite beam according to the present invention.

FIG. 2 is a vertical sectional front view of a beam end of the composite beam.

FIG. 3 is a longitudinal sectional front view of a beam steel joint part in the composite beam.

FIG. 4 is a perspective view of an essential part in which a part of the composite beam is broken.

FIG. 5 is an explanatory view of a construction method.

FIG. 6 is a side view of a main part showing a state in which a composite beam is erected on an SRC column.

[Explanation of symbols]

 1 ... pillar 2 ... centrifugally formed square steel tube concrete 3 ... steel frame 4 ... floor concrete

Claims (1)

(57) [Claims] 1. An end of a beam having a vertically long rectangular cross section and
The thickness of the plate and lower plate is made larger than the thickness of the left and right side plate
A square steel pipe and centrifugally formed using the square steel pipe as a mold
A centrifugal molding RHS concrete comprising a concrete composite beams, wherein a central portion of the beam was synthesized beam of S Zomata steel and the floor concrete.