JP2002013248A - Concrete column with built-in continuous fiber reinforced pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a concrete column whose earthquake resisting property is heightened. SOLUTION: The concrete column is constituted by installing a continuous fiber reinforced pipe 10 formed by placing a continuous fiber sheet 12 around a cylindrical thin-plate steel pipe 11 and a main column reinforcement in a standing manner and integrating internal concrete 3 placed within the pipe 10 and external concrete 4 placed in such a manner as to have a prescribed cross section.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concrete column with a built-in continuous fiber reinforced pipe, and more particularly to a concrete column with a built-in continuous fiber reinforced pipe using a cylindrical pipe wound with a continuous fiber sheet as an internal reinforcing material.

[0002]

2. Description of the Related Art In an earthquake-resistant diagnosis performed on an existing building, for an existing ineligible building determined to be "insufficient in earthquake resistance", an appropriate earthquake-resistant reinforcement method is taken based on a design for earthquake-resistant reinforcement. In this seismic retrofitting method, a reinforcing structure method in which a continuous fiber sheet such as a carbon fiber sheet, an aramid fiber sheet, or a glass fiber sheet as a continuous fiber reinforcing material is wound around a structural body to be reinforced and subjected to shear reinforcement is often used. Continuous fiber sheet has a tensile strength of about 10 compared to steel.
It has the advantage that the specific gravity is about 1/4 (in the case of carbon fiber), and it has been used as a material instead of steel plate reinforcement. The pillars of buildings are generally rectangular in cross section,
It is known that a large shear reinforcing effect can be obtained by winding a continuous fiber sheet in the circumferential direction of the column section and impregnating the sheet with an epoxy resin to solidify the sheet. When wound around a column having a circular cross section, in addition to the effect of shear reinforcement, it is effective in increasing the axial compression strength and improving the toughness during axial compression.

[0003]

The continuous fiber reinforcing material represented by the continuous fiber sheet has a high performance as a mechanical reinforcing material for the member as described above, and is used for removing pillars and the like of an existing building from the outside. It is often used for applications such as seismic reinforcement. On the other hand, as a new structure using a continuous fiber reinforcing material, there is a technical development in which a conventional reinforcing bar is used as a bending tensile reinforcing member of a beam material. However, there were no cases in which compression and shearing action was used from the construction stage of a new column as an internal reinforcing material for the column material dominant.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, apply a continuous fiber sheet to a newly installed column subjected to a high axial force, and toughen the column under a high axial force and a high shear force. It is an object of the present invention to provide a concrete column with a built-in continuous fiber reinforced pipe which can ensure the performance.

[0005]

In order to achieve the above-mentioned object, the present invention provides a continuous fiber reinforced pipe formed by winding a continuous fiber sheet around a cylindrical pipe and a column main reinforcement, and the continuous fiber reinforced pipe is provided inside the continuous fiber reinforced pipe. It is characterized in that the cast concrete is integrated with the cast concrete to form a predetermined column cross section.

It is preferable that the continuous fiber reinforcing pipe has a structure in which a continuous fiber sheet is wound around a thin steel pipe and fixed with an impregnated adhesive resin.

[0007] The continuous fiber reinforced pipe may have a portion in which the number of winding layers of the continuous fiber sheet is different.

[0008] It is preferable that the column main reinforcement is arranged along the inner surface of the continuous fiber reinforced pipe.

[0009] Lightweight concrete is previously poured into the continuous fiber reinforced pipe to form an internal concrete column, the internal concrete column is installed in a predetermined column form, and a predetermined reinforcing arrangement is performed. It is also preferable to cast an external concrete into the inside to integrate with the internal concrete column, and to use a precast concrete having a predetermined column cross section.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a concrete column with a built-in continuous fiber reinforced pipe according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic perspective view showing a part of a concrete column 1 incorporating a continuous fiber reinforced pipe according to the present invention. A portion of concrete is removed so that the relationship between the continuous fiber reinforced pipe 10 (hereinafter simply referred to as the reinforced pipe 10) installed inside the column and the main reinforcing bar 2 as a composite reinforcing material can be understood. FIG. 3A shows the cross section of this column.
As is clear from both figures, one section of the concrete column has a rectangular section which is divided into inner and outer parts with the continuous fiber reinforced pipe 10 as a boundary, and is constructed by placing concretes 3 and 4. In this embodiment, concrete 3 and 4 inside and outside reinforcing pipe 10 are used.
Is cast with ordinary concrete of the same design strength.
Also, changing the type of the external concrete 4 mainly composed of columns has merit in terms of mechanics and lightening of the building.

FIG. 2 shows a reinforcing pipe 10 used in FIG. As shown in FIG. 1, the reinforcing pipe 10 includes a thin steel pipe 11 as a shape member and a continuous fiber sheet 12 attached around the steel pipe 11. In other words, in order to keep the soft sheet-like continuous fiber sheet 12 as a material in a cylindrical shape, a cylindrical thin steel pipe 11 is used as a mold. In the present embodiment, an off-the-shelf spiral duct formed by processing a thin plate into a tubular shape is used for the steel pipe 11. Although the thin steel pipe 11 is not considered in the column strength, it can be expanded even after the continuous fiber sheet 12 reaches the tensile breaking strain, so that the cylindrical concrete can be expected to have a restraining effect on the internal concrete 3.

In order to manufacture the reinforcing pipe 10, first, an impregnated adhesive resin such as an epoxy resin is applied as an undercoat to the outer periphery of a thin steel pipe 11 as a mold. Continuous fiber sheet 1
Paste 2 around. In the case of single layer winding,
The same impregnated adhesive resin 13 is applied as a top coat on the wound continuous fiber sheet 12. For example, using a spiral duct of φ400 for the thin steel pipe 11, winding one layer of the carbon fiber sheet 12 (300 g / m ² ), the pipe height is 2.5 m
In this case, the weight of the reinforcing pipe 10 becomes about 22 kg, and it is very lightweight. For this reason, it is possible to laminate and wind a plurality of layers of carbon fiber sheets 12 as necessary. At this time, the weight increase for each additional layer over the entire length is +
It is about 3kg. Also, as shown in FIG.
By further partially overlapping the carbon fiber sheet 12B on the single-layer wound carbon fiber sheet 12A, it is possible to expect the reinforcing pipe 10 to have the same effect as a stirrup, and to reduce the weight of the reinforcing pipe 10. . As the type of the continuous fiber sheet 12, a woven fabric in which carbon fibers are aligned in one direction (unidirectional woven fabric)
In addition to the carbon fiber sheet consisting of, aramid fiber sheet,
Other glass fibers and polyacetal fibers are possible.
As the impregnated adhesive resin 13, a methacrylic resin is preferable in addition to an epoxy resin.

FIGS. 3 (a) and 3 (b) show examples of a column cross section in which the reinforcing pipe 10 is applied to a column. As shown in FIG.
The reinforcing pipe 10 is disposed at the center of the column section and has a diameter such that it is almost inscribed in the main reinforcing bar 2 surrounded by the band reinforcing bar 5.
0 is built. It is advantageous that the pillar area surrounded by the reinforcing pipe 10 is as large as possible. At this time, it is also possible to cast concrete having different strength into the reinforcing pipe 10 as the internal concrete 3. Further, as described later, the reinforcing pipe 10 can be manufactured as a precast concrete product. In this case, it is preferable to use a reinforcing pipe 10 in which ultra-lightweight concrete is cast into the internal concrete 3 and use high-strength concrete as the external concrete 4. FIG. 3 (b) shows the core muscle 6
Shows an example of a column cross section where reinforcement is arranged. When the core muscle 6 is arranged, the diameter of the reinforcing pipe 10 to be used becomes small,
Although the cross-sectional area of the internal concrete 3 is reduced, an effect of shear reinforcement and improvement of the bond splitting strength by the arranged core bars 6 can be expected. The ratio of the internal concrete 3 surrounded by the reinforcing pipe 10 to the total cross-sectional area of the column is preferably set to an area ratio such that the internal concrete 3 alone can support a long-term load.

FIG. 4 shows a longitudinal section of a concrete column 1 in which a reinforcing pipe 10 is applied to the column. FIG. 3 (b)
2 shows the reinforcing pipe 10 and the reinforcing bars 2, 5, and 6 in the reinforcing bar arrangement state. The height of the reinforcing pipe 10 housed inside the column is set equal to or slightly shorter than the inner height of the column 1.

Next, the construction of the above-described concrete column will be described. When casting cast-in-place concrete,
First, the reinforcement pipe 10 is dropped into the inner space surrounded by the main reinforcement 2 in a state where the column arrangement is performed. At this time, it is preferable that a spacer (not shown) raised by about 10 mm from the top of the lower layer slab concrete is arranged at the lower end of the reinforcing pipe 10. Since the reinforcing pipe 10 is lightweight, the reinforcing bars 2,5,5
6 can be easily fixed using a binding wire and a fixing jig, and a predetermined position can be held.

The continuity of the reinforcing pipe 10 with the inner concrete 3 and the outer concrete 4 does not affect the axial compression performance of the column. Outside concrete 4
It is also preferable to integrate them. In this case, dowels (not shown) penetrating the reinforcing pipe 10 at predetermined intervals from inside to outside.
Is preferably attached. In addition to the dowel streaks, a shear cotter that maintains shear continuity can be attached to the inner and outer surfaces of the reinforcing pipe 10.

FIG. 5 shows a modified example in which the main reinforcement 2 is arranged in the reinforcing pipe 10. By restricting the outer periphery of the main bar 2 with the reinforcing pipe 10 in this manner, it is possible to prevent adhesion splitting fracture and to improve the shear strength of the column member. At this time, by making the concrete strength of the internal concrete 3 and the concrete of the external concrete 4 different, the weight of the column can be reduced and the cross section can be reduced.

In the above description, it is assumed that the reinforcing pipe 10 is erected in the laid pillar construction portion and cast-in-place concrete is cast. However, it is also possible to manufacture the precast concrete member. . Hereinafter, a process of manufacturing a precast concrete column will be briefly described.
Pour internal concrete with the reinforcement pipe upright. It is preferable to use lightweight and ultra-lightweight concrete for the internal concrete. The reinforcing pipe integrated with the concrete is installed so as to be suspended in a lower pillar form placed horizontally on a predetermined bed. At this time, it is important to arrange the reinforcing pipe so that the central axis of the reinforcing pipe and the central axis of the column are aligned by using a spacer. After the upper reinforcing bars have been arranged, the upper formwork is attached, and external concrete is poured from predetermined filling holes. At this time, since the lower surface of the reinforcing pipe in the lower mold has a smooth circular convex shape, there is no problem in filling the concrete. The precast concrete column member manufactured in this manner is lightweight and has high toughness, so that it is an effective component in the concrete composite construction method.

[0019]

As described above, according to the present invention,
This has the effect that the toughness of the newly installed column can be secured under high axial force and high shear force.

[Brief description of the drawings]

FIG. 1 is a partial perspective view showing one embodiment of a concrete column incorporating a continuous fiber reinforced pipe according to the present invention.

FIG. 2 is an overall perspective view showing an example of reinforcing a reinforcing pipe applied to a concrete column with a built-in continuous fiber reinforcing pipe.

FIG. 3 is a cross-sectional view of a concrete column incorporating a continuous fiber reinforced pipe.

FIG. 4 is a longitudinal sectional view of the concrete column with a built-in continuous fiber reinforced pipe shown in FIG. 3 (b).

FIG. 5 is a cross-sectional view showing a modified example of a concrete column incorporating a continuous fiber reinforced pipe.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 concrete column 2 main rebar 3 inner concrete 4 outer concrete 5 stirrup 6 core rebar 10 continuous fiber reinforced pipe 11 thin steel pipe 12, 12A, 12B continuous fiber sheet 13 impregnated adhesive resin

Claims (5)

[Claims] 1. A continuous fiber reinforced pipe formed by winding a continuous fiber sheet around a cylindrical pipe and a column main bar are erected, and are cast so as to form a predetermined column cross section with internal concrete cast in the continuous fiber reinforced pipe. A concrete column with a built-in continuous fiber reinforced pipe, wherein the concrete column is integrally formed with a set external concrete. 2. The concrete column with a built-in continuous fiber reinforced pipe according to claim 1, wherein the continuous fiber reinforced pipe has a continuous fiber sheet wound around a thin steel pipe and fixed with an impregnated adhesive resin. 3. The concrete column with a built-in continuous fiber reinforced pipe according to claim 2, wherein the continuous fiber reinforced pipe has portions where the number of wrapping layers of the continuous fiber sheet is different. 4. The concrete column with a built-in continuous fiber reinforced pipe according to claim 1, wherein the column main reinforcement is arranged along the inner surface of the continuous fiber reinforced pipe. 5. An internal concrete column by previously casting light-weight concrete into the continuous fiber reinforced pipe, installing the internal concrete column in a predetermined column form, performing a predetermined reinforcing arrangement, and 2. The concrete column with a built-in continuous fiber reinforced pipe according to claim 1, wherein an external concrete is poured into the formwork to integrate with the internal concrete column to form a precast concrete having a predetermined column cross section.