JPH0849293A - Reinforcing method for column/beam joint part of ferroconcrete - Google Patents

Abstract

PURPOSE:To enhance the bearing force and stiffness of a column/beam joint part by covering the column head part and column leg part, which are located right over the column/beam joint part in a ferro-concrete structure, with a steel band, and thereby restraining part of the column head part and column leg part. CONSTITUTION:A plate 1 of steel band having a thickness smaller than the slab thickness is fixed to those positions in a concrete form for column which correspond to the column head part and column leg part, and a cast-in-place ferro-concrete column 2 and a cast-in-place ferro-concrete beam 3 are joined together, and the inside of the column/beam joint part is equipped with reinforcement using spiral hoop bars 4 in circular shape. Thereby the performance of the joint part is enhanced, and the cross-section of column can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for reinforcing a column / beam joint portion of a reinforced concrete structure or a PC structure.

[0002]

2. Description of the Related Art In a conventional column-beam joint of a reinforced concrete structure, a column main bar a ₁ of a column a penetrates the column-beam joint, and a beam main bar b ₁ of a beam b penetrates the column-beam joint. It is bent and fixed at the same portion and is reinforced by the columnar bar a ₂ . (See FIGS. 7 and 8)

[0003]

The cross section of the column-beam joint of the reinforced concrete structure is the same as the normal column cross section.
In terms of seismic engineering, in the structural design, the column cross-sectional dimension is determined not by the performance of the column itself, but rather by satisfying the performance of the column-beam joint, resulting in a larger cross section of the column itself. In many cases

Even when the main bar of the lower end of the beam is bent upward before the center of the column-beam joint to fix the column-beam joint, the bending resistance of the beam is exerted. The joints, stigmas, and pedestals are severely deteriorated. Furthermore, in order to increase the performance of seismic engineering such as the strength and toughness of the column-beam joint, it is possible to cover the area around the column and the column-beam joint with a steel plate. Must.
However, in a reinforced concrete building, due to the thickness of the fireproof coating, a dimensional difference occurs between the outer dimensions of the columns in design planning and construction, leaving problems in design and construction.

The present invention has been proposed in view of the above-mentioned problems of the prior art.
Providing a method of reinforcing reinforced concrete columns and beam joints that improves the structural performance of beam joints, reduces the cross-section of columns compared to conventional construction methods, and solves design problems and construction problems. It is in.

[0006]

In order to achieve the above-mentioned object, according to the method for reinforcing a reinforced concrete column / beam joint according to the present invention, a column / beam joint directly above a column of a reinforced concrete structure or a PC structure is directly overlaid. Further, the column head and the column base positioned directly below are partially covered with a band plate made of a T-shaped steel having a width equal to or smaller than the slab thickness.

According to the second aspect of the present invention, the band-shaped steel band plate for reinforcing the column is made smaller than the column outer dimension so that the outer surface of the refractory material attached to the band plate matches the column outer dimension.

[0008]

According to the present invention, a reinforced concrete structure or P
By covering a part of the column head and the column foot of the C structure column with the band plate made of Ta-shaped steel, the concrete of a small part of the column head and the column base is restrained, and as a result, the column head,
The strength and toughness of the concrete of the column base are enhanced, and the proof strength and toughness of the column-beam joint are dramatically increased.

According to a second aspect of the present invention, the outer dimensions of the band-shaped steel band plate are made slightly smaller than the column outer dimensions,
By matching the external dimensions of the columns together with the thickness of the refractory material mounted on the band plate, the design can be reasonably accommodated.

[0010]

The present invention will be described below with reference to the illustrated embodiments. 1 and 2 show a first embodiment of the present invention, in which a band-shaped steel band plate 1 having a width less than or equal to a slab thickness is fixed at the positions of the stigma and the pedestal of the column form, and concrete is attached to the column The cast-in-place and the cast-in-place reinforced concrete columns 2 and the cast-in-place reinforced concrete beams 3 thus constructed are joined together, and the column-beam joints are additionally reinforced by circular spiral hoop reinforcements 4. In the figure, 5 is the main columnar bar, 6 is the columnar bar, 7 is the main beam, and 8 is the rib. When this method is applied to the precast method, a T-shaped steel band plate is fixed at the positions of the column head and column base of the formwork at the PC factory, and concrete is poured to produce the PC column. A pillar is set at a predetermined position, a half-PC beam and a half-PC floor slab are set, and concrete on the floor is placed along with the pillar-beam joint and the beam upper part.

According to the above-mentioned embodiment, the performance of the column-beam joint is improved and the cross section of the column is reduced as compared with the conventional method by the reinforcing method using the band plate 1 made of the T-shaped steel and the circular spiral hoop bar 4. it can. 3 and 4 show another embodiment of the present invention, in which a band-shaped steel band plate 1 having a width equal to or smaller than the slab thickness is fixed at the positions of the stake and the pedestal of the cast-in-place reinforced concrete column form, In addition to pouring concrete, an anchor portion 7a in which the lower end bar of the beam main bar 7 of the cast-in-place reinforced concrete column 2 is bent upwards before the center of the column-beam joint is bent, and is cast in this way. The reinforced concrete column 2 and the cast-in-place reinforced concrete beam 3 are joined together, and the column-beam joint is reinforced by the circular spiral hoop reinforcement 4.

When this construction method is applied to the PC construction method, as in the conventional precast construction method, in the PC construction method, the column-shaped steel band plates are fixed at the positions of the column head and the column foot in the PC construction and concrete is poured. Then, set a half precast beam in which the end of the bottom beam main bar is bent upward,
The circular spiral hoop reinforcement 4 is set at the beam joint, the half precast floor slab is set, and the column-beam joint and the floor upper part are concrete placed.

FIGS. 5 and 6 show still another embodiment of the present invention. In the embodiment shown in FIGS. 3 and 4, the band-shaped steel band plate 1 disposed on the column head and the column base is provided. Is slightly smaller than the outer dimension of the column and larger than the outer dimension of the column stirrup 6, and the fire-resistant material 9 made of fire-resistant paint or solid fire-resistant material is attached to the side surface of the band plate 1 made of the same type of U-shaped steel. It is attached to the steel band plate 1, and the thickness of the band plate 1 and the refractory material 9 are adjusted to match the column outer dimensions,
Made the design rational. The construction method is substantially the same as that of the above-mentioned embodiment in both the cast-in-place concrete construction method and the PC construction method.

In the figure, the same parts as those in the above embodiment are designated by the same reference numerals.

[0015]

As described above, according to the present invention, the column-shaped steel band plate in which the column heads and column pedestals located directly above the column-beam joints of the reinforced concrete structure or PC structure have a width of not more than the slab thickness. As a result of being covered by, the concrete of the column head and column base is partially constrained, the strength and toughness of the concrete of the column head and column base are increased, and as a result, the strength and toughness of the column-beam joint are increased. Is dramatically improved, and the column cross section can be reduced as compared with the conventional method.

According to the second aspect of the present invention, the outer surface of the refractory material mounted on the band plate made of the U-shaped steel for reinforcing the column is made to coincide with the outer shape of the column. It is a solution.

[Brief description of drawings]

FIG. 1 is a plan cross-sectional view showing a column-beam joint portion configured according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of FIG.

FIG. 3 is a plan cross-sectional view showing a column-beam joint portion formed according to another embodiment of the present invention.

FIG. 4 is a vertical sectional view of FIG.

FIG. 5 is a plan cross-sectional view showing a column-beam joint portion configured according to still another embodiment of the present invention.

FIG. 6 is a vertical sectional view of FIG.

FIG. 7 is a plan sectional view of a column / beam joint formed by a conventional method.

FIG. 8 is a vertical cross-sectional view of FIG.

[Explanation of symbols]

 1 Band-shaped steel band plate 2 Cast-in-place reinforced concrete column 3 Cast-in-place reinforced concrete beam 4 Circular spiral hoop bar 5 Column main bar 6 Column girder 7 Beam main bar 8 Rib bar 9 Fireproof material

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hitoshi Sasaki 4-6-15 Sendagaya, Shibuya-ku, Tokyo Fujita Co., Ltd.

Claims (2)

[Claims] 1. A column-shaped steel band having a width of less than or equal to a slab thickness for a column head portion and a portion of a column base portion located directly above and directly below a column-beam joint in a column of a reinforced concrete structure or a precast (PC) structure. A reinforcing method for a reinforced concrete column-beam joint characterized by covering with a plate. 2. The reinforced concrete pillar / beam according to claim 1, wherein the band-shaped steel band plate for reinforcing the pillar is made smaller than the outer dimension of the pillar so that the outer surface of the refractory material attached to the band plate matches the outer shape of the pillar. How to reinforce the joint.