JP3583948B2 - How to form a seismic slit - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for forming a seismic slit.
[0002]
[Prior art]
As shown in FIG. 7, a conventional method of forming a seismic slit in a reinforced concrete structure is to fix a slit member 24 to a separator 27 and inner and outer molds 28 and 29 at a joint portion between a column 25 and a wall 26, and Concrete 32 was cast alternately on the column formwork side 30 and the wall formwork side 31 so as not to bend.
[0003]
[Problems to be solved by the invention]
However, the method of forming the earthquake-resistant slit as described above was inefficient because concrete was alternately cast on the column formwork side and the wall formwork side.
[0004]
The present invention has been made in view of such a problem, and an object of the present invention is to provide an efficient method of forming a seismic slit.
[0005]
[Means for Solving the Problems]
Means for solving the above problem is that the invention according to claim 1 is characterized in that a slit material, which is a porous elastic material mixed with aluminum powder that reacts with alkali moisture, is formed on the inner surface of the formwork at the joint between the column and the wall. After that, the concrete is poured into the formwork, the aluminum powder reacts with the alkali moisture therein to self-expand the slit material forward, and the tips thereof are brought into contact with each other. It is characterized.
[0006]
According to the first aspect of the present invention, since the opposing slit members are expanded forward and their tip portions are brought into contact with each other, it is possible to easily form a seismic slit capable of cutting off the entire cross section of the wall thickness. Even if concrete is cast from either the column formwork side or the wall formwork side, sufficient fluidity and filling properties can be ensured.
[0007]
According to a second aspect of the present invention, in the first aspect, a part of the slit member is covered with a water-soluble polyethylene sheet .
[0008]
According to the invention of claim 2, since the sheet of water-soluble polyethylene is melted by the alkali moisture in the cast concrete and the compressed stress is released, the concrete is pushed out and self-expanded. Convenient because foaming can be prevented.
[0009]
A third aspect of the present invention is characterized in that, in the first or second aspect, the porous elastic material is any one of a rubber type, a polyethylene type, and a polyvinyl alcohol type .
[0010]
According to the invention of claim 3, the porous elastic material self-expands forward by self-releasing the compressive stress in the poured concrete.
[0011]
Further, according to the invention of claim 4 , a slit material, which is a bellows-shaped rubber tube that expands forward by injecting air, is provided so as to face the inner surface of the form at the joint between the column and the wall, and concrete is provided in the form. After that, the slit material is inflated with air to bring the tip portions into contact with each other .
[0012]
According to the fourth aspect of the present invention, when air is introduced into the rubber tube, the rubber tube expands forward and comes into contact with the tip of the opposed rubber tube, so that a simple configuration can be achieved.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a method for forming an earthquake-resistant slit of the present invention will be described with reference to the drawings. FIG. 1 is a front view of an earthquake-resistant slit formed at a joint between a column and a wall in a reinforced concrete structure, and FIG. 2 is a cross-sectional view of a method of forming an earthquake-resistant slit according to the first embodiment.
[0014]
As shown in FIG. 1, the earthquake-resistant slit 1 is formed at the joint between the column 3 and the wall 4 of the reinforced concrete structure 2 so as to prevent torsion and stress from being concentrated on the structure 2.
[0015]
The earthquake-resistant slit 1 is formed using a slit material 5 as shown in FIG. The slit material 5 is a porous elastic material 6 mixed with aluminum powder in order to increase foaming power, and is pressed into a hard plastic case 7 in a compressed state with the same length as the height of the wall. . Examples of the porous elastic material 6 include rubber, polyethylene, and polyvinyl alcohol. According to these principles, the container is confined in one direction in a compressed state, and the stress of the container is released in the same direction as the compression direction to cause self-expansion. Further, aluminum powder having a self-expanding power is mixed so as to assist the self-expansion.
[0016]
A large number of water penetration holes 8 are opened on the side surface of the case 7, and the front and side surfaces of the case 7 are covered with a water-soluble polyethylene sheet 9 that reacts only to aluminum moisture. The case 7 is detachably attached to the joint case 10, and a joint material 11 such as a sound insulating rubber is press-fitted into the joint case 10.
[0017]
When the slit member 5 is attached to the inner surfaces of the outer mold frame 12 and the inner mold frame 13 with nails 14 and these mold frames 12 and 13 are assembled and formed, as shown in FIG. It is attached so as to face the inner surface of the wall form 15 at the joint between the column 3 and the wall 4.
[0018]
Next, as shown in (2) of the figure, since there is an appropriate gap 16 between the slit members 5, concrete 18 is removed from either the wall form side 15 or the column form side 17. When poured, the water-soluble polyethylene sheets 9 on the front and side surfaces of the case 7 are melted by the alkali moisture in the concrete 18, and the stress of the porous elastic body is released to be in a state of self-expansion. At this time, the aluminum powder mixed into the porous elastic material 6 reacts with the alkali moisture of the concrete 18, and the porous elastic material 6 self-expands in the forward direction, and its tips contact each other, The concrete 18 in the molds 15 and 17 is divided into concrete 18a on the wall form and concrete 18b on the column form.
[0019]
Next, when the molds 15 and 17 are disassembled after the concretes 18a and 18b have hardened, the seismic slits 1 are formed across the entire cross section of the wall thickness.
[0020]
FIGS. 4 and 5 show a slit member 5 according to another embodiment. FIG. 4 shows a case 7 in which the front surface of a case 7 is covered with a plastic plate 19 which can be slid up and down. After the 18 has been cast, it is pulled up to open the front surface of the case 7 (not shown). When joining is expected, the porous elastic material 6 is divided in the height direction to correspond. When the slump state of the concrete is soft, a foamed urethane material may be used instead of the porous elastic material 6.
[0021]
FIG. 5 shows the case 7 in which the front surface of the case 7 is covered with two synthetic resin films 20, and these films 20 are joined by a drawstring 21 at the center. Therefore, when the drawstring 21 is pulled out after the concrete 18 is cast into the molds 15 and 17, the film 20 opens on both sides and the front surface of the case 7 is opened (not shown).
[0022]
FIG. 6 shows a second embodiment of a method for forming an earthquake-resistant slit, in which a bellows-shaped rubber tube 22 is used for the slit member 5, except for this point. In the same way. This is because after the concrete 18 is poured into the molds 15 and 17, the rubber tubes 22 are inflated forward with air to bring the tip portions into contact with each other, whereby the concrete 18 in the molds 15 and 17 is brought into contact. Is divided into concrete 18a on the wall form side and concrete 18b on the column form side to form the earthquake-resistant slit 1.
[0023]
【The invention's effect】
Since the opposing slit members expand forward and the tip portions come into contact with each other, an earthquake-resistant slit that can cut off the entire cross section of the wall thickness can be easily formed.
[0024]
Even if concrete is cast from either the column formwork or the wall formwork, sufficient fluidity and filling properties can be ensured.
[0025]
The work of attaching the slit material to the formwork is easy, and there is no post-work, so that work efficiency can be improved.
[0026]
Since the surface is covered so as to react with the alkali moisture, it is possible to prevent the reaction with only the moisture before the concrete is poured, and the handling becomes easy.
[Brief description of the drawings]
FIG. 1 is a front view of a wall on which an earthquake-resistant slit is formed.
2 (1) is a plan view of a slit material, (2) is a side view of a joint material case, (3) is a side view of a slit material case, and (4) is a front view of the slit material.
FIGS. 3 (1) and (2) are cross-sectional views of a method of forming an earthquake-resistant slit.
4 (1) is a plan view of a slit material, (2) is a side view of a joint material case, (3) is a side view of a slit material case, and (4) is a front view of the slit material.
5 (1) is a plan view of a slit material, (2) and (4) are front views of a case of the slit material, and (3) is a plan view of the slit material.
FIGS. 6 (1) and (2) are cross-sectional views of a method for forming a seismic slit according to the second embodiment.
FIG. 7 is a cross-sectional view of a conventional method for forming a seismic slit.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Seismic slit 2 Reinforced concrete structure 3, 25 Column 4, 26 Wall 5, 24 Slit material 6 Porous elastic material 7 Case 8 Moisture penetration hole 9 Sheet 10 Joint case 11 Joint material 12, 29 Outer frame 13, 28 Internal Form 14 Nail 15, 31 Wall Form Side 16 Gap 17, 30 Column Form Side 18, 18a, 18b, 32 Concrete 19 Plastic Plate 20 Film 21 Pull String 22 Rubber Tube 27 Separator

Claims (4)

After providing a slit material, which is a porous elastic material mixed with aluminum powder that reacts with alkali moisture, facing the inner surface of the form at the joint between the column and the wall, concrete is poured into the form. A method of forming an earthquake-resistant slit by reacting aluminum powder with alkali water therein to cause the slit material to self-expand and to contact the tips. The method for forming an earthquake-resistant slit according to claim 1, wherein a part of the slit material is covered with a sheet of water-soluble polyethylene . The method according to claim 1, wherein the porous elastic material is one of a rubber, a polyethylene, and a polyvinyl alcohol . A slit material, which is a bellows-shaped rubber tube that expands forward by injecting air, is provided facing the inner surface of the form at the joint between the column and the wall, and after the concrete is poured into the form, the slit material is formed. A method of forming an earthquake-resistant slit, characterized in that air is inflated with air and the tips thereof are brought into contact with each other .

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