JP2876478B1 - Crack induced structure - Google Patents

Abstract

Abstract: [PROBLEMS] It is not necessary to provide a sealing material on the front side of a concrete skeleton at a site where an induced crack occurs, and it is not necessary to replace the sealing material due to aging and maintenance is easy. It is not necessary to perform the work, the workability is good, the cost can be reduced,
Furthermore, it is not necessary to provide an induction joint on the front side of the concrete body, and the appearance of the design can be improved. SOLUTION: A gutter-shaped gap serving as a drainage channel 6 having an opening 6a on a side, an opposing piece 6b communicating with the gap to form a gap wider than the gap, and the gutter-shaped drainage channel 6 And a water-stopping material 8 and 9 having elasticity and good adhesion to concrete, which are arranged around the perimeter of the concrete body 1. The water-stopping member 5 communicates with the induced crack 3 generated in the concrete frame 1. The water stop 5 is buried in the concrete skeleton 1 with 6a facing the outside of the concrete skeleton 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for inducing cracks in a concrete skeleton.

[0002]

2. Description of the Related Art There is a possibility that cracks may occur on the outer wall of a concrete skeleton such as a reinforced steel frame concrete structure or a reinforced concrete structure due to drying shrinkage of the concrete, leading to a decrease in the strength of the skeleton. Therefore, in order to prevent the occurrence of cracks in a large number of arbitrary locations, a crack-inducing joint is applied in advance to a predetermined location of the concrete skeleton, stress is concentrated at this location, and cracks are actively generated, and other locations are cracked. To prevent cracks from occurring.

In order to induce this crack, conventionally, for example, FIG.
As shown in the figure, the front side of the outer wall of the concrete skeleton 1 where the concrete shrinkage crack is to be generated is 20 mm.
The induction joint 2 is formed in the vertical direction with a partial cross-sectional defect, and cracks 3 are actively generated from this location. 4 in the figure
Indicates a wall muscle.

When a crack 3 is generated, water such as rainwater penetrates through the crack 3 from the surface of the concrete skeleton 1 and enters the inside of the skeleton, for example, corroding the wall reinforcement 4 or leaking water to the inner wall side. Therefore, a well-known sealing material such as polyurethane or polyethylene is used for the induction joint 2.
Filling 21 prevents water from entering crack 3.

However, the useful life of the sealing material 21 is limited. For example, the sealing material 21 that has passed 3 to 5 years after application is peeled off from concrete or cracks occur due to the curing shrinkage of the sealing material 21 itself. And sealing material
Water penetrates through the cracks 3 and penetrates into the inner wall side.

Therefore, it is necessary to replace the sealing material 21. Until the replacement, the sealing material 21 is conventionally provided as a means for stopping water, for example, as disclosed in Japanese Patent Application Laid-Open No. 4-323437 shown in FIG. And a water blocking plate 22 integrated with the sealing material 21 is provided.

The water stop plate 22 is made of a soft plastic, and has a drainage space 23 opened on the back surface of the sealing material 21 and a contraction follower anchor 24 extending on both sides from the drainage space 23.
It comprises a pair of holding grips 25 for sandwiching the back surface of the sealing material 21.If the sealing material 21 peels off from the concrete or cracks occur in the sealing material 21, rainwater entering from the surface of the concrete is The water enters the drainage space 23 on the back surface of the container 21 and falls there to be discharged to the outside.

Accordingly, water does not enter into the cracks 3 generated in the concrete skeleton 1 and the entry of water into the inner wall 26 is blocked.

[0009]

A method of merely filling the induction joint 2 shown in FIG. 4 with the sealing material 21. In addition to the sealing material 21 shown in FIG.
Method of arranging 22; in each case, concrete skeleton 1
Must be formed to form the induced joint 2, and the covering thickness is insufficient by the depth of the defect, and therefore,
In order to secure the thickness required for the structure even at the formation site of the induction joint 2, for example, a thickness equal to or more than the depth of the induction joint 2 is used.
It is necessary to increase the size by about 20 to 30 mm.

[0010] In addition, since any of these methods is primarily intended to stop the water with the seal material 21, it is necessary to cope with the deterioration of the seal material 21 as well as the need for the seal material 21. When replacement is required due to a change and the seal material 21 stops functioning, there is a possibility that water leakage may occur.

Furthermore, since the induced joints appear vertically on the front side of the concrete frame 1, it is inappropriate when the joints are not desired to be displayed due to the design of the exterior of the building.

In the case of the method shown in FIG. 5, the periphery of the water blocking plate 22 is apt to be a so-called junka (bean plate), and a gap is formed in the concrete so that the water that has entered the sealing material 21 does not flow into the drainage space 23. Water may leak to the inner wall 26 through the crack 3.

An object of the present invention is to eliminate the inconvenience of the prior art and eliminate the necessity of providing a sealing material on the front side of the concrete body at the site where the induced cracks occur, eliminating the need for replacement due to aging of the sealing material and facilitating maintenance. Without the need to overstrike the concrete skeleton for trigger joints,
An object of the present invention is to provide a crack-inducing structure that has good workability, can reduce costs, and does not need to provide an induction joint on the front side of a concrete skeleton, and can improve the appearance of a design.

[0014]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention firstly provides a gutter-shaped space which becomes a drainage channel with an open side, and which communicates with the space and is wider than this space. Induced cracks formed in the concrete skeleton by forming a water-stopping body with opposing pieces forming voids and a water-stopping material disposed around the gutter-shaped drainage channel and having good adhesion to concrete. In this case, the water blocking body is buried in the concrete body so that the opening faces the outside of the concrete body.

Second, the gist of the present invention is that the induced crack is generated by a notch formed on the concrete surface when the concrete body is constructed.

Third, it is essential that the water stopping body is buried in a place corresponding to the notch provided in the concrete body, and fourth, that the water stopping body is buried in a place corresponding to the induction joint provided in the concrete body. Is what you do.

Fifth, the drainage channel of the water stopping body is filled with a member that can be melted after being buried in the concrete frame to secure a void. Sixth, the drainage channel of the water stopping body is filled with concrete. The gist of the invention is to provide a member having water permeability for preventing concrete from entering at the time of installation.

According to the first aspect of the present invention, the large thickness formed by the opposing pieces provided in the water blocking body reduces the cover thickness of the concrete frame, and cracks are induced in this portion. Therefore, without providing a sealing material on the front side of the concrete skeleton at the site of the induced crack, water such as rainwater is allowed to enter from the induced crack, and the rainwater that has entered the induced crack is guided to the large void. Drain into the communicating drainage channel and discharge to the outside. And
Since a waterproof material with elasticity is provided around the water-stopping body, this water-stopping material deforms following the drying shrinkage of the concrete,
This prevents water that has entered the cracks from turning to the inner wall. Furthermore, since the water-stopping body has a shape with less irregularities due to a water-stopping material covering the periphery, no jumper is generated in the surrounding concrete.

Therefore, without providing a sealing material, water is caused to penetrate into the induced cracks, and the infiltrated water is surely guided to the drainage channel in the concrete body, thereby preventing water from entering the inner wall side. It is not necessary to overstrike concrete to secure the required cover thickness, the sealing material is not exposed to the outside, the appearance is good, and there is no need to replace the sealing material that has deteriorated due to aging. Becomes

According to the second aspect of the present invention, in addition to the above effects, the induced crack is generated by a notch formed on the concrete surface when the concrete body is constructed. By simply protruding toward the surface and attaching it to the formwork, it can be reliably and easily induced to the site where cracks are to be generated, and the workability is good.

According to the third aspect of the present invention, in addition to the above-described functions, the crack induced by the notch formed in the concrete skeleton always communicates with the water stopping body embedded in the concrete skeleton. Water can be reliably received by the gutter-shaped drainage channel, and water can be reliably prevented from entering the inner wall.

According to the fourth aspect of the present invention, in addition to the effects of the first and second aspects of the present invention, even when an induced joint is provided in the concrete frame, a crack is induced at the induced joint. Therefore, if the water stopping body is arranged in the concrete body at the portion corresponding to the induction joint, the crack communicates with the water stopping body, and the crack enters the gutter-shaped drainage channel provided in the water stopping body. Can guide water.

According to the fifth aspect of the present invention, in addition to the above-described operation, the drainage channel of the water stopping body is filled with a chemical-soluble member so that the concrete can be drained at the time of placing concrete. It can be prevented that it penetrates into and is closed, and that the opposing pieces of the waterstop are crushed and deformed by the poured concrete pressure. Then, after filling the concrete, the filling member is melted to secure a void as a drainage channel. Therefore, a water stopping body having a void serving as a drainage channel can be easily embedded in the concrete body.

According to the present invention described in claim 6, according to claim 1,
In addition to the function of the present invention as described in claim 4, the drainage channel of the water stopping body is provided with a member having water permeability for preventing concrete from entering, so that the concrete can be drained when the concrete is poured. Invading the inside and closing it,
Also, the opposing pieces of the water stopping body can be prevented from being crushed and deformed by the cast concrete pressure. Then, even after the concrete is cast, the water infiltrates into the drainage channel as it is, but other things do not infiltrate, so that the water stopping body having the void serving as the drainage channel can be easily embedded in the concrete body.

[0025]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a cross-sectional plan view showing an embodiment of a crack-inducing structure according to the present invention. As a concrete skeleton 1, for example, a waterproof body 5 having a void serving as a drainage channel 6 is buried inside a concrete outer wall or the like. A crack 3 was induced from the front side of No. 1 and formed, and this crack 3 was communicated with the drainage channel 6.

As shown in FIG. 4, for example, an expandable joint material (trade name "Nicken Expan") is used as the water stopping body 5. This is a long one provided with a gutter-shaped drainage channel 6 made of PVC (polyvinyl chloride) and having a substantially U-shaped cross section. The drainage channel 6 is approximately 20 mm in height, and has a height from both ends of the opening 6a. A facing piece 6b of about 15 mm is protruded. In this case, the width of the opening 6a is formed to be narrower than the width of the drainage channel 6, and the interval between the opposing pieces 6b is formed to be larger than the width of the drainage channel 6 to secure a large gap between the opposing pieces 6b. Be prepared to do it.

In the figure, reference numeral 7 denotes ribs integrally provided on the inner wall of the drainage channel 6 and the outside of the opposing piece 6a for reinforcing and adhering to concrete. Further, the side wall of the drainage channel 6 facing the opening 6a is formed in a curved portion 6c which is slightly curved inward so as to be able to cope with deformation due to concrete shrinkage.

The outside of the drainage channel 6 is covered with a waterproof material 8 made of a synthetic rubber mainly composed of EPT (ethylene / propylene / terpolymer) having excellent durability and crack resistance, and both sides of the drainage channel 6. Only the portion corresponding to the portion is covered with a waterproof material 9 having elasticity such as butyl rubber and having good adhesion to concrete.

Before the construction of the water stopping body 5, as shown in FIG. 4, the water stopping body 5 is made of EPT (ethylene propylene terpolymer).
A curing tape 10 is adhered to the surface of the water-stopping material 8 made of synthetic rubber whose main component is, and a release paper 11 is adhered to the surface of the water-stopping material 9 made of butyl rubber.

Next, a method of causing an induced crack and a method of arranging the above-described water-blocking body at a location where the induced crack occurs will be described. When constructing, for example, the outer wall which is the concrete frame 1, for example, after arranging the wall reinforcement 4, the part of the drainage channel 6 of the water stop 5 is wound around the wall reinforcement 4 with a tape such as butyl tape and fixed. At this time, the opening 6 of the drainage channel 6
a so as to face the outside of the outer wall.

Further, since the water stopping body 5 comes into contact with the wall streaks 4, a tape such as butyl tape is wound around the wall streaks 4 at a portion which comes into contact with the water stopping body 5 for rust prevention of the wall streaks 4.

On the other hand, as a member for preventing concrete from flowing into the space between the opposing pieces 6b of the water stopping body 5 and for opposing the concrete pressure, for example, a member 12 which can be dissolved after being embedded in the concrete frame 1 as styrene foam or As shown in FIG. 3, as a member 13 having water permeability to prevent concrete from entering at the time of casting concrete, a continuous long-fiber nonwoven fabric made of polypropylene or the like, which is filled with trade name “Tafnel EX”, Alternatively, a base bone 14 having a mountain-shaped cross section made of a material such as a plastic mesh is disposed with the mountain part facing the opening 6a.

Then, as shown in FIG.
An L-shaped corner member or a thin sheet of vinyl chloride is attached as a notch forming member 16 to the formwork 15 and its tip is 6 m.
It is made to protrude inward from the mold by about m.

On the other hand, a curing tape adhered to the water stopping body 5
The mold release paper 11 and the release paper 11 are peeled off, and concrete 18 is poured into the formwork 15. In this case, it is desirable to remove the curing tape 10 and the release paper 11 as late as possible. The poured concrete 18 is a meltable member 12 or a member 13 having water permeability.
Thus, intrusion into the opposing piece 6b is prevented, and the opposing piece 6b is prevented from being pressed and deformed by the concrete pressure cast by the members 12, 13 and the base bone 14.

After the concrete 18 has hardened, the formwork 15 is dismantled and the notch forming member 16 is removed. As shown in FIG. 1, the notch 17 is formed on the front side of the concrete frame 1 by the notch forming member 16, and the water stopping body is formed. 5 is buried inside concrete 18.

When styrofoam is filled as a dissolvable member 12 after embedding in the concrete frame 1 in the space between the opposing pieces 6b of the water stopping body 5, this is dissolved using a dissolving liquid such as alcohol or limonel. , Facing piece 6b
An air gap communicating with the drainage channel 6 is secured therebetween.

When the concrete 18 dries and shrinks, the notch 17
The crack 3 is induced and formed from the point (3), and the crack 3 reaches a gap formed between the opposed pieces 6b. In this case, since the gap formed between the opposing pieces 6b is large, the cover thickness of the concrete 18 is reduced, so that not only the crack 3 is easily generated but also the tip of the crack 3 is formed by the opposing piece 6b. Easily reach the gap between them,
The crack 3 and the water stop 5 communicate with each other. And crack 3
Because the notch 17 on the front side of the concrete skeleton 1 where the is induced is open without providing a sealing material,
Water such as rainwater enters the inside of the crack 3, and flows into the drainage channel 6 through a gap formed between the opposed pieces 6b, and falls there, and falls there, for example, a horizontal joint on the first floor of a building. Flows through a pipe made of vinyl chloride or the like, and is discharged to the outside.

In this case, even if the member 13 having water permeability or the underlying bone 14 is disposed in the space between the opposed pieces 6b,
Since these are permeable to water, the inflow of water from the crack 3 to the drainage channel 6 is not hindered. Further, since the opening 6a to the drainage channel 6 is formed to be narrow, there is no possibility that the water once taken into the drainage channel 6 easily escapes from here.

At this time, the area around the water blocking body 5 other than the opening 6a is covered with the water blocking materials 8 and 9, so that the water from the cracks 3 is prevented from flowing in directions other than the drainage channel 6. In addition, since the periphery of the drainage channel 6 is covered with the water-stopping materials 8 and 9, irregularities are reduced in the outer shape, and the concrete 18 can sufficiently wrap around the water-stopper 5, thereby preventing the occurrence of junkers. The ribs 7 projecting outside the opposing piece 6b of the water body 5 can improve the adhesion between the opposing piece 6b and the concrete 18.

In the case where the notch 17 is formed so as to induce the crack 3 at a predetermined position as in the above embodiment,
Since the crack 3 is so small that its existence is difficult to be recognized if it is several meters away, for example, the concrete skeleton 1
This is effective when it is not necessary to form vertical joints on the front side of the building, and when the appearance of the building is not desired to show the joints.

Incidentally, it is also possible to provide a joint for inducing the crack 3. In this case, the vertical joint is, for example, 2.5 mm in order to secure the rigidity of the concrete frame 1.
It is preferable to provide them at intervals of m, the pillars are provided within 600 mm, the corners are provided within 600 mm from the inner surface of the orthogonal wall, and the horizontal joints are preferably provided at the joint of each floor of the building and at intervals of 4 m.

[0042]

As described above, the crack-inducing structure according to the present invention has the following features. First, water does not enter the induced crack without providing a sealing material on the front side of the concrete frame at the site of the induced crack. Water was infiltrated into the induced cracks, and this water flowed into the gutter-shaped drainage channel formed in the waterproof body embedded in the concrete body, and was discharged to the outside. There is no need for conventional joints due to missing parts on the front side of the skeleton and sealing materials to be provided here, and there is no need to install sealing materials or replace sealing materials that have cracked due to aging. Good maintenance, easy maintenance, and cost reduction.

Further, the appearance of the building design is good,
This is effective for structures that do not want to show seals or joints on the outside.It is not necessary to provide a joint with a defect on the front side of the concrete body. There is no need to overstrike.

Secondly, since a water-stopping material having elasticity is provided around the water-stopper having a drainage channel buried in the concrete body, the water-stopper deforms following the drying shrinkage of the concrete, and cracks. This prevents water that has penetrated into the inner wall from turning around. Further, since the water stopping body has good adhesion to concrete, no jumper is generated in the surrounding concrete, and the water that has entered the induced crack can be surely guided to the drainage channel.

Third, if the induced crack is generated by a notch formed on the concrete surface when the concrete body is constructed, for example, when the concrete is cast, a thin plate or the like is projected toward the casting surface and attached to the formwork. In this way, cracks can be reliably and easily induced at the site where cracks are to be generated, and the workability is good.The cracks induced by the notch always communicate with the water blocking body embedded in the concrete body, so penetration from the cracks Water can be reliably received by the gutter-shaped drainage channel, and the intrusion of water into the inner wall can be reliably prevented.

Fourth, even when an induction joint is provided in the concrete frame, a crack is induced at the location of the induction joint. Therefore, a waterproof body can be provided in the concrete frame at a portion corresponding to the induction joint. In this case, the crack communicates with the water stopping body, and the water entering from the crack can be guided to a gutter-shaped drainage channel provided in the water stopping body.

Fifthly, the drainage channel of the water stopping body is filled with a material or the like which can be dissolved with a chemical or the like, or a member having water permeability for preventing concrete from entering is provided. However, it is possible to prevent concrete from penetrating into the drainage channel during concrete placement and blocking the drainage channel, or to prevent the drainage channel from being deformed by concrete pressure, etc. By dissolving, it is possible to secure a space as a drainage channel as it is in the case of a member having water permeability, and at the same time, it is possible to prevent the space from being deformed by concrete pressure. Therefore, a water stopping body having a void serving as a drainage channel can be easily embedded in the concrete body, and the void can be reliably secured.

[Brief description of the drawings]

FIG. 1 is a cross-sectional plan view showing an embodiment of a crack-inducing structure of the present invention.

FIG. 2 is a cross-sectional plan view showing a crack-inducing structure according to an embodiment of the present invention in a construction state.

FIG. 3 is a cross-sectional plan view showing another embodiment of the crack inducing structure of the present invention, in which another filling member is provided.

FIG. 4 is a perspective view of a water blocking body used in the crack inducing structure of the present invention.

FIG. 5 is a cross-sectional plan view showing an example of a conventional crack-inducing structure.

FIG. 6 is a cross-sectional plan view showing another example of the conventional crack inducing structure.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Concrete skeleton 2 ... Induction joint 3 ... Crack 4 ... Wall streaks 5 ... Water stop body 6 ... Drainage channel 6a ... Opening 6b ... Opposite piece 6c ... Bend part 7 ... Rib 8 ... Water stop material 9 ... Water stop material 10 ... Healing Tape 11 ... Release paper 12 ... Dissolvable member 13 ... Water-permeable member 14 ... Foundation bone 15 ... Form 16 ... Notch forming member 17 ... Notch 18 ... Concrete 21 ... Sealing material 22 ... Water blocking plate 23 ... Drainage space 24 ... contraction follow anchor 25 ... holding grip 26 ... inner wall

Claims (6)

(57) [Claims] 1. A gutter-shaped gap serving as a drainage channel having an open side, an opposing piece communicating with the gap to form a gap wider than the gap, and being disposed around the gutter-shaped drainage channel. A water-blocking body is composed of a water-stopping material having good elasticity and adhesiveness to concrete, and in order to communicate with the induced crack generated in the concrete skeleton, the water-stopping body is directed toward the outside of the concrete skeleton to open the water-blocking body. A crack-inducing structure characterized by being buried in a concrete body. 2. The crack-inducing structure according to claim 1, wherein the induced crack is generated by a notch formed on the concrete surface when the concrete skeleton is constructed. 3. The crack-inducing structure according to claim 1, wherein the water stopping body is buried in a portion corresponding to a notch provided in the concrete skeleton. 4. The water stopping body is buried in a portion corresponding to an induced joint provided in a concrete skeleton.
2. The crack-inducing structure according to 1. 5. The crack-inducing individual structure according to claim 1, wherein the drainage channel of the water stopping body is filled with a member which can be melted after being embedded in the concrete frame to secure a void. 6. The crack-inducing structure according to claim 1, wherein a member having water permeability for preventing concrete from entering when the concrete is poured is disposed in the drainage channel of the water stopping body.