JPH07317211A - Steel pipe reinforced concrete pile - Google Patents

Abstract

PURPOSE:To provide a steel pipe reinforced concrete pile which is capable of omitting a fire resistant coating. CONSTITUTION:A continuous reinforcing material whose tensile strength is higher than that of concrete 2, which is filled up in a steel pipe 1, is buried in the concrete 2 along the longitudinal direction of the steel pipe 1. As for the reinforcing material, there are available reinforcements 3 or a structural steel laid out substantially in the center of the steel pipe or a plurality of reinforcement laid out with a specified spacing or resin-solidified substance reinforced with high strength fibers. In addition to that, the reinforcing materials should be laid out preferably over the whole length of the steel pipe. The reinforcing materials may be laid out only between upper and lower beam joints.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filled steel tube concrete column used as a column of a building.

[0002]

2. Description of the Related Art As is well known, a filled steel pipe concrete structure is a kind of steel-concrete composite structure in which the inside of a steel pipe is filled with concrete, and has recently been widely adopted as a structure for high-rise buildings.

A column in such a filled steel pipe concrete structure, that is, a filled steel pipe concrete column formed by filling the steel pipe with concrete has a risk of the steel pipe becoming brittle due to a high temperature during a fire. As in the case of steel columns, it is necessary to apply a fireproof coating to steel pipes. However, it is said that the fireproof coating can be omitted when the axial stress generated in the column is small and the structural strength of the column is sufficiently large. In the above, in order to reduce the cost, the fireproof coating is omitted only on the pillars on the upper floors where the axial stress is small.

[0004]

However, when the fireproof coating of the pillars on the upper floors is omitted as described above, floors that require fireproof coating and floors that do not require fireproof coating will coexist. It becomes complicated. That is,
Since there will be differences in the floor plan of each floor depending on the presence or absence of fireproof coating, not only the flexibility of the floor plan will be impaired, but the dimensions and tile division of the curtain wall of the outer wall will differ slightly from floor to floor. Therefore, standardization and standardization cannot be sufficiently achieved.

Therefore, in a building having a filled steel pipe concrete structure, there is a demand for omitting the fireproof coating on the columns of the lower floors as well as the upper floors, and an effective means for realizing this is being sought. It was

In order to omit the fireproof coating of the columns of the lower floors, it is sufficient to reduce the axial stress of the columns. For that purpose, the column cross section is enlarged or the steel pipe is filled. A high-strength concrete material may be used as the concrete, but such a thing is unrealistic because the column cross section becomes unnecessarily large and the construction cost remarkably increases.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an effective filled steel pipe concrete column in which a fireproof coating can be omitted.

[0008]

DISCLOSURE OF THE INVENTION The present invention is a filled steel pipe concrete column which is used as a column of a building in which a steel pipe is filled with concrete, and which has a long reinforcing material having a higher tensile strength than the concrete. It is characterized in that it is embedded in the concrete along the axial direction of the steel pipe. As the reinforcing material, it is possible to use a reinforcing bar or steel frame arranged substantially at the center of the steel pipe, a plurality of reinforcing bars arranged at predetermined intervals along the inner surface of the steel pipe, a resin solidified body reinforced by high-strength fibers, or the like. The reinforcing material may be arranged over the entire length of the steel pipe, or may be arranged only between the upper and lower beam joints.

[0009]

[Operation] By embedding a reinforcing material composed of reinforcing bars, steel frames, resin solidified bodies, etc. in concrete, the reinforcing material exerts a shear reinforcing effect on the concrete and restrains thermal deformation of the concrete in case of fire. . Therefore, by providing such a reinforcing material, the axial stress of the column is substantially reduced without increasing the cross section of the column and without increasing the strength of the concrete itself, and thus the refractory coating can be omitted. Let's train.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. First, FIGS. 1 and 2 show a filled steel pipe concrete column (hereinafter, simply referred to as a column) C1 of the first embodiment. This column C1 has a filled steel pipe concrete structure in which concrete 2 is filled in a steel pipe 1 having a circular cross section, but one reinforcing bar 3 as a reinforcing material is arranged over the entire length of the steel pipe 1 at a substantially central position of the steel pipe 1. It is reinforced and embedded in concrete 2. In this pillar C1, the steel pipe 1 to which the reinforcing bars 3 have been previously attached by the connecting material 4 is erected at a predetermined position, the beam steel frame 6 is joined to the beam joint portion 5, and then the concrete 2 is poured into the steel pipe 1. It is constructed by filling. Note that the steel pipe 1 may be erected and then the reinforcing bar 3 may be arranged therein.

In the pillar C1 having the above-mentioned structure, the reinforcing bars 3 arranged in the concrete 2 exert a shearing reinforcing effect on the concrete 2 and restrain the thermal deformation of the concrete 2 at the time of fire. As a result, it is possible to prevent the concrete 2 from cracking or buckling. Therefore, only by providing such a reinforcing bar 3, it is possible to substantially reduce the axial stress degree of the column C1 without enlarging the column cross section or using high-strength concrete. The pillar C1 allows the fireproof coating to be omitted even when it is used on the lower floors.

Since the column C1 of this embodiment has a simple structure in which only one reinforcing bar 3 is added to a conventional general filled steel pipe concrete column, the addition of this reinforcing bar 3 does not increase the cost. The construction cost can be reduced as a whole, and the construction cost can be reduced as a whole by reducing the cost by omitting the fireproof coating in the low-rise portion.

The cross-sectional area of the reinforcing bar 3 as a reinforcing member may be set appropriately in consideration of the cross-sectional area of the entire column C1 and the strength required for this column C1. Even if it is only 1% or less of the cross-sectional area of the pillar C1, the axial stress degree can be surely greatly reduced.

FIG. 3 shows another embodiment of the present invention. In the pillar C1 of the above-mentioned embodiment, the reinforcing bar 3 was laid out over the entire length of the steel pipe 1, but in the pillar C2 of this embodiment, the reinforcing bar 3 was laid only between the upper and lower beam joints 5, 5. The reinforcing bar 3 is omitted in the beam connection portion 5. By doing so, the structure in the beam joint 5 where the joining work of the steel pipe 1 and the beam steel frame 6 is performed is simplified and the workability is improved.

FIG. 4 shows still another embodiment. In the pillar C3 of the present embodiment, instead of the reinforcing bar 3, a steel frame 7 having a relatively small cross section made of cross-shaped steel is provided at a substantially central position in the steel pipe 1 over its entire length or between the upper and lower beam joints 5, 5. However, also in this case, the same effects as those of the pillars C1 and C2 of the above-described embodiment can be obtained. The steel frame 7 is not limited to the cross-shaped steel, but I-shaped steel, H-shaped steel, a circular or rectangular steel pipe having a small cross section, or any other cross-sectional shape can be adopted.

5 and 6 show still another embodiment. The pillar C4 of this embodiment has a plurality of (eight in the illustrated example) reinforcing bars 8 arranged along the inner surface of the steel pipe 1 at predetermined intervals along the entire length of the steel pipe 1. Reference numeral 9 is a connecting reinforcing bar connecting the reinforcing bars 8. Also in the pillar C4 of the present embodiment, similarly to the pillars C1 to C3 of each of the above-mentioned embodiments, the reinforcing bar 8 exerts the shear reinforcing effect on the concrete 2 and restrains the thermal deformation at the time of fire, therefore, the axial stress of the pillar C4 is The refractory coating can be omitted by reducing the degree. Further, in the pillar C4 of the present embodiment, each reinforcing bar 8 contributes to the enhancement of the horizontal proof strength of the pillar C4, which is advantageous during an earthquake or the like.

Further, a pillar C5 of another embodiment shown in FIG.
Indicates that each of the reinforcing bars 8 in the pillar C4 is omitted in the beam joint portion 5. In this case, the reinforcing bar 8 does not have the effect of increasing the horizontal proof strength, but the construction at the beam joint 5 is simplified as in the case of the column C2 described above.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments, and various design changes can be arbitrarily made. For example, as the reinforcing material, it is common to use the reinforcing bars 3 and 8 and the steel frame 7 as in the above embodiment, but other materials such as those having a higher tensile strength than the concrete 2, that is, a higher Young's modulus are used. Metallic materials other than steel can be used, and it is of course possible to use a combination of different kinds of reinforcing materials having different materials and cross-sectional shapes. In any case, the cross-sectional size and the installation position of the reinforcing material may be appropriately set in consideration of the material of the reinforcing material, the cross-sectional size of the column, the strength required for the material, and the like.

As the reinforcing material, not only a metal material but also a resin solidified body reinforced by high strength fibers, that is, high strength fibers such as carbon fiber, glass fiber, aramid fiber, etc. are bundled and impregnated with resin such as epoxy resin. It is also possible to employ a long linear body that is solidified by being solidified. Of course, such a resin solidified body may be appropriately combined with another reinforcing material and employed. However, when such a resin solidified body is used, it is necessary to secure a large fogging of the concrete 2 in consideration of its heat resistance.

[0020]

As described above, in the filled steel pipe concrete column of the present invention, a long reinforcing material having higher tensile strength than that of the concrete filled in the steel pipe is provided along the axial direction of the steel pipe. Since it is a structure to be buried together,
Reinforcement provides shear reinforcement to concrete and restrains thermal deformation of concrete in case of fire, thus substantially reducing column axial stress without enlarging the section of the column or increasing the strength of the concrete itself. As a result, there is an excellent effect that the fireproof coating on the steel pipe can be omitted. Since it is sufficient to use inexpensive general-purpose building materials such as reinforcing bars, steel frames, or fiber-reinforced resin solidified materials as the reinforcing material, the cost increase by using the reinforcing material is slight, and the fireproof coating can be omitted. As a result, it is possible to greatly reduce the cost as a whole.
Also, if the reinforcing material is provided over the entire length of the steel pipe, it is possible to make the reinforcing material bear the horizontal proof stress, and if the reinforcing material is provided only between the upper and lower beam joints, the construction at the beam joints can be performed. It can also avoid complications.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a filled steel pipe concrete column according to an embodiment of the present invention.

FIG. 2 is a horizontal sectional view of the column.

FIG. 3 is a vertical sectional view of a filled steel pipe concrete column which is another embodiment of the present invention.

FIG. 4 is a horizontal sectional view of a filled steel pipe concrete column according to still another embodiment of the present invention.

FIG. 5 is a vertical cross-sectional view of a filled steel pipe concrete column which is still another embodiment of the present invention.

FIG. 6 is a horizontal sectional view of the column.

FIG. 7 is an elevational view of a filled steel tube concrete column according to still another embodiment of the present invention.

[Explanation of symbols]

 C1-C5 Filled steel pipe concrete pillar 1 Steel pipe 2 Concrete 3 Reinforcing bar 5 Beam joint part 7 Steel frame 8 Reinforcing bar.

Claims (7)

[Claims] 1. A filled steel pipe concrete pillar used as a pillar of a building, in which concrete is filled in a steel pipe, wherein a long reinforcing material having a tensile strength higher than that of the concrete is provided along the axial direction of the steel pipe. A filled steel pipe concrete column, which is embedded in the concrete. 2. The filled steel pipe concrete column according to claim 1, wherein the reinforcing member is a reinforcing bar arranged substantially at the center of the steel pipe. 3. The filled steel pipe concrete column according to claim 1, wherein the reinforcing member is a steel frame arranged substantially at the center of the steel pipe. 4. The filled steel pipe concrete column according to claim 1, wherein the reinforcing member is a plurality of reinforcing bars arranged at predetermined intervals along the inner surface of the steel pipe. 5. The filled steel tube concrete column according to claim 1, wherein the reinforcing material is a resin solidified body reinforced with high strength fibers. 6. The reinforcing material is arranged over the entire length of the steel pipe.
Alternatively, the filled steel pipe concrete column according to item 5. 7. The filled steel pipe concrete column according to claim 1, 2, 3, 4, or 5, wherein the reinforcing member is arranged between the upper and lower beam joints.