JPH07310399A - Concrete filled steel tubular columns - Google Patents

Abstract

(57) [Summary] [Purpose] Protect the internal rebar of concrete-filled steel tubular columns from heat damage in the event of a fire. [Structure] In a concrete-filled steel tubular column 1, a diaphragm 2 is provided with a through hole 4 for reinforcing bars 6, and the reinforcing bars 6 are arranged in the through holes 4 via an inorganic heat insulating spacer 5. [Effect] Even if the heat during a fire is transmitted through the steel pipe material 1 and the diaphragm 2, the inorganic heat insulating spacer 5 suppresses the heat transmission to the reinforcing bar 6 and prevents the strength of the reinforcing bar 6 from being deteriorated.
Therefore, in the event of a fire, only the steel pipe material 1 on the outer periphery will decrease the yield strength, including the column-beam joints, and the reinforced concrete portion inside can maintain the yield strength, and the column-beam joints will have a fireproof coating. It functions as a reinforced concrete column without applying.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reinforced concrete filled steel tubular column used in the fields of construction and civil engineering.

[0002]

2. Description of the Related Art In recent years, as a column material used in the field of construction or civil engineering, a steel pipe column is known in which a rectangular or circular steel pipe is reinforced with reinforcing bars for the purpose of reinforcing strength and filled with concrete.

FIG. 4 is a vertical cross-sectional view of a concrete-filled steel pipe column in which reinforcing bars are arranged in the prior art. 1 is a rectangular or circular steel pipe material which is an outer shell of the steel pipe column, and 2 is an inner surface of the steel pipe material. In the diaphragm attached by welding, the diaphragm 2 is provided with a concrete filling hole 3 and a through hole 4 for penetrating the reinforcing bar 6, and the reinforcing bar 6 is penetrated into the through hole 4 and the inside of the steel pipe material 1 Is filled with concrete to form a concrete-filled steel tubular column.

Further, in Japanese Laid-Open Patent Publication No. 1-290844, in a structure of a beam-column joint portion of a concrete column with reinforcing bars, a column outer shell body only at a position where a beam member is attached is made of a steel plate,
A diaphragm is attached to the inside of the column outer shell, a reinforcing bar is penetrated through a plurality of holes provided in the diaphragm, and an end portion of the diaphragm is projected from a steel plate which is the column outer shell to form an outer beam member. Of the concrete filling joined with
A joint structure of columns and beams is disclosed.

Further, in Japanese Laid-Open Patent Publication No. 1-154944, in a structure of a column-beam joint portion of a concrete column containing a PC steel wire, a column outer shell only at a position where a beam member is attached is called a joint plate. Disclosed are a structural column and a frame structure which are made of a material, a pressure receiving plate is attached inside the connection plate, and a PC steel wire is penetrated through a plurality of holes provided in the pressure receiving plate to fill with concrete. .

[0006]

In the reinforcing structure of the concrete-filled steel pipe column in the above-mentioned prior art, when the concrete-filled steel pipe column encounters a fire, the heat of fire is applied from the steel pipe material or the joint plate to the diaphragm or the pressure receiving plate. It will be transmitted inside the concrete-filled steel tubular column through the plate. At this time, the heat transmitted from the diaphragm or pressure plate propagates to the reinforcing bar or the PC steel wire to raise the temperature,
There is a problem that the strength of the reinforcing bar or PC steel wire is deteriorated. As a countermeasure for this, in the column-beam joint, a method of applying a fireproof coating to the outer surface of the steel pipe material to prevent the heat of the fire from propagating to the reinforcing bars is taken, but the construction of the fireproof coating is complicated and causes a cost increase. It was.

[0007]

According to the present invention, a diaphragm having a plurality of through holes is fixed to the inner surface of a steel pipe material, and an inorganic heat insulating spacer having a hollow hole is attached to the plurality of through holes of the diaphragm. It is intended to provide a concrete-filled steel pipe column comprising reinforcing bars arranged through the hollow holes of the inorganic heat insulating spacer.

[0008]

According to the present invention, in the concrete-filled steel pipe column, the diaphragm is provided with a through hole for reinforcing bar, and the reinforcing bar is arranged through the inorganic heat insulating spacer in the through hole.
Even if the heat during a fire is transmitted through the steel pipe material and the diaphragm, the inorganic heat insulating spacer suppresses the heat transmission to the reinforcing bar and prevents the strength deterioration of the reinforcing bar.

Therefore, at the time of a fire, only the steel pipe material on the outer periphery, including the beam-column joint portion, will have a reduced yield strength, and the reinforced concrete portion inside can maintain the bearing strength. It functions as a reinforced concrete column even if no fireproof coating is applied to the part.

[0010]

1 is a vertical sectional view of a concrete-filled steel tubular column according to the present invention. In FIG. 1, reference numeral 1 is a steel pipe material which is an outer shell of a steel pipe column, and 2 is a diaphragm fixed to a position corresponding to an inner surface of the steel pipe material 1 to which a beam material (not shown) is attached by welding means such as welding. The diaphragm 2 is provided with a concrete filling hole 3 in the center.

Further, the diaphragm 2 is provided with a through hole 4 around the concrete filling hole 3, and an inorganic heat insulating spacer 5 is attached to the through hole 4. The inorganic heat insulating spacer 5 and the through hole 4 are attached to each other by the screw cut on the inner surface of the through hole 4 and the screw 5 cut by the inorganic heat insulating spacer 5.
Fix by tightening with b.

A hollow hole 5 is formed in the inorganic heat insulating spacer 5.
a is provided, and the reinforcing bar 6 is arranged to penetrate the hollow hole 5a.

The inorganic heat insulating spacers 4 prevent heat in a fire or the like from propagating to the reinforcing bars 6 through the steel pipe material 1 and the diaphragm 2, and have a heat insulating property.
Further, a material having high heat resistance is used, and for example, ceramics, asbestos, rock wool, ALC type concrete, calcium hydroxide, calcium silicate molding material and the like are desirable.

In the steel pipe column according to the present invention, concrete (not shown) is filled inside the steel pipe material 1 in the field in the above-mentioned rebar arrangement state to complete the steel pipe column.

FIG. 2 is a sectional view taken along the line A--A of FIG. 1, showing various shapes of the steel pipe column. The shape of the steel pipe material 1 which is the outer shell of the steel pipe column and the arrangement state of the inorganic heat insulating spacers 5 are shown. Is shown. 2A shows the case where the steel pipe material 1 is a rectangular steel pipe column, and FIG. 2B shows the case where the steel pipe material 1 is a steel pipe column having a shape formed by the U-shaped material 1a and the straight plate 1b. C) is steel pipe material 1
Indicates a circular steel pipe column formed of the circular member 1c.

Further, in FIGS. 2A, 2B, and 2C, an inorganic heat insulating spacer 5 having a hollow hole 5a at the center is arranged at four corners of the diaphragm 2.

Although the concrete filling hole 3 is provided in the center of the diaphragm 2 as an example, it may be formed by cutting out the four corners of the diaphragm 2.

Next, FIG. 3 shows a means for attaching the inorganic heat insulating spacer 5 to the diaphragm 2. In addition to the screwing method shown in FIG. 1, there are the following fixing means.

FIG. 3A shows an example in which the screw 5c is cut on the inorganic heat insulating spacer 5 and tightened and fixed by the nut 5d. In FIG. 3B, the inorganic heat insulating spacer 5 is press-fitted and fixed to the diaphragm 2. As an example, FIG. 3C shows an example in which the inorganic heat insulating spacer 5 is formed of an insulator and press-fitted. In FIG. 3D, the inorganic heat insulating spacer 5 made of the insulator having the taper 5e is press-fitted into the diaphragm 2. The fixed examples are shown respectively.

The inorganic heat insulating spacer 5 of the present invention is fixed and integrated with the diaphragm 2 by the above method.

[0021]

As described above, according to the present invention, since the reinforcing bars are arranged by providing the inorganic heat insulating spacers in the through holes for the reinforcing bars of the diaphragm, a fire occurs outside the concrete-filled steel pipe column. However, the heat transmitted to the rebar through the diaphragm can be suppressed by the inorganic heat insulating spacers to prevent the temperature rise of the rebar, and the steel reinforced concrete part inside the steel pipe column burns out the steel pipe material that is the outer shell. Even so, as a reinforced concrete column, including the beam-column joints, it has the effect of maintaining the yield strength even in the event of a fire.

Further, it is not necessary to perform a complicated work such as applying a fireproof coating to the outer surface of the steel pipe column.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a concrete-filled steel tubular column according to the present invention.

2 is an example showing various shapes of the concrete-filled steel tubular column according to the present invention, and is a cross-sectional view taken along line AA of FIG.

FIG. 3 is a cross-sectional view showing a method for fixing an inorganic heat insulating spacer according to the present invention.

FIG. 4 is a vertical cross-sectional view showing a reinforcing bar structure of a concrete-filled steel pipe column in a conventional technique.

[Explanation of symbols]

 1 Steel pipe material 2 Diaphragm 3 Concrete filling hole 4 Through hole 5 Inorganic heat insulating spacer 6 Reinforcing bar

Front page continuation (72) Inventor Riji Inosa Marunouchi 1-2-2 Marunouchi, Chiyoda-ku, Tokyo Japan Steel Tube Co., Ltd. (72) Nobuyuki Nakamura 1-2 1-2 Marunouchi, Chiyoda-ku, Tokyo Nihon Steel Pipe Co., Ltd. (72) Inventor Yoshiyuki Fujiwara 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Steel Pipe Co., Ltd.

Claims (1)

[Claims] 1. A hollow pipe of the inorganic heat insulating spacer, wherein a diaphragm having a plurality of through holes is fixed to the inner surface of a steel pipe material, and an inorganic heat insulating spacer having a hollow hole is attached to the plurality of through holes of the diaphragm. A concrete-filled steel tubular column made by arranging reinforcing bars through the pipe.