JP2000211959A - Impervious structural material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable cement to surely drive onto the inclined surface even when cement content is reduced and exhibit impervious performance over a long period even when crack occurs by mixing a fiber into an impervious structural material. SOLUTION: An impervious structural material is driven so as to cover the upper surface of a piling up part 1a to build an impervious layer 21. The impervious structural material is bonded to a soil material comprising sand and gravel by mixing the material with polypropylene 22 and hardly made to flow because of stickiness and compensates initial strength, because the viscosity coefficient is increased. The impervious structural material can be driven in large amount, because the material remains on the slope 24 without flowing when driven onto the slope 24. Cement of the impervious layer 21 is solidified after passing about 1 month to exhibit strength. Cement can be added in a small amount of <=200 kg per m3 product. When crack is produced in the bottom 5, unmodified bentonite 6 in the impervious layer 21 contains water and is swollen and penetrated into crack to block the crack and prevent leakage of water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-blocking structural material applied to civil engineering structures and the like.

[0002]

2. Description of the Related Art FIGS. 11 and 12 are cross-sectional views showing an example of a dumping site for disposing of industrial waste. In each of FIGS. Concrete is poured to cover the surface of the portion 1a, and a water-impervious layer for water-impermeation, 3 is a water-impervious sheet laid on the water-impervious layer 2, and 4 is deposited on the bottom 5 side of the water-impervious sheet 3 The protective sand is used to protect the sheet 3.

The water-impervious layer 2 made of concrete is usually made of a soil material such as sand or gravel, which is a main material, a low-permeability material such as bentonite or kaolin, which has a water-impervious property, and a cement or the like which solidifies these. The material is stirred and mixed with a mixer to form a water-blocking structural material. The water-blocking structural material is cast to construct a water-blocking layer 2.

[0004] As shown in FIG. 13, bentonite 6 is a kind of clay mineral, and has a crystal structure having positive sodium ions 8 inside crystal plates 7 a and 7 b. And water molecules 9 attached thereto, and has a structure including interlayer water composed of the water molecules 9 between the layers of the crystal plates 7a and 7b. Water molecules 9 between this layer
Since the ion concentration of the interlayer water is higher than the ion concentration of the water molecules 9 around the bentonite 6, an osmotic pressure difference is generated, and the surrounding water molecules 9 are replenished between the layers by the osmotic pressure difference. The replenishment of the water molecules 9 is performed until the sodium ion 8 and the crystal plates 7a and 7b are bonded to each other, and the bonding force and the osmotic pressure are balanced. Thus, the bentonite 6 is replenished with the water molecules 9 around it, so that the bentonite 6 has the property of swelling as shown in FIG.

In FIG. 14, water molecules 9 are replenished from the surroundings and swell to increase in volume, so that they have the effect of filling small gaps in the water blocking layer 2 and exhibit water blocking performance. This swelling is called osmotic swelling, and since the ion concentration of the interlayer water is high, the water molecules 9 once taken in between the layers cannot easily go out of the crystal plates 7a and 7b. . However, when dried, it goes out from the interlayer to the outside, and its volume is reduced and it is aggregated.

[0006] Cement used as a solidifying material solidifies by the pozzolanic reaction and develops strength. The calcium ion 10 contained in cement plays a central role in the pozzolanic reaction.

[0007]

Next, in a state of being mixed with cement as a solidifying material, as shown in FIG. 15, the bentonite 6 has a strong cation exchange property and has a +1 valent sodium ion inside. 8 and +2 valent calcium ions 10 contained in the cement of the solidifying material are exchanged. The sodium ions 8 go out of the bentonite 6 and the calcium ions 10 are taken in the bentonite 6. This calcium ion 10
Has a stronger bonding force with the crystal plates 7a and 7b than the sodium ions 8. Therefore, once dried, the crystal plate 7
There is a problem that the water molecules 9 are not replenished between the layers a and 7b, the amount of the water molecules 9 between the layers is reduced, and the swelling property is reduced. As shown in FIG. 16, if the bentonite 6 does not swell too much, the water W slowly passes through the gap 11 of the bentonite 6, so that the water barrier performance cannot be sufficiently exhibited. In addition, as for the cement which is a solidifying material, calcium ions 10 which are the main component of the solidification reaction are taken into the bentonite 6, so that the calcium ions 10 are insufficient, so that the strength developability is low.

[0008] That is, there is a problem in that if the cement exhibiting strength and the bentonite 6 for providing water shielding are mixed as they are, the original advantages of both are canceled out.

In order to maintain the water-blocking performance of the bentonite 6, it is sufficient to reduce the amount of calcium ions 10 so that
What is necessary is just to reduce the amount of cement. However, if the amount of cement is reduced, the initial strength of the impermeable structural material immediately after casting is reduced, and when cast on a slope such as a slope, concrete flows along the slope, resulting in a large amount of continuous Can not be cast. Since a single casting can only be performed for a few cm,
It is necessary to perform a plurality of castings, which increases the construction period. Therefore, it is difficult to adopt a technique for reducing the amount of cement.

In addition, there is a problem that cracks occur when the impermeable layer 2 dries. That is, a water-blocking layer 2 is formed by mixing a solidified material and a low water-permeable material with such a conventional water-blocking viscous soil or soil material, and slurried.
When this is constructed, the impermeable structural material shrinks when it dries, and cracks may occur. The cracks become water channels, and water leaks through the water channels, so that the water-blocking layer 2 cannot exhibit the water-blocking performance.

As described above, conventionally, if the amount of cement is reduced in order to maintain the water barrier performance of the bentonite 6, the initial strength immediately after casting is insufficient. There is a drawback that it cannot be cast in large quantities. Further, when the water-blocking layer 2 shrinks during drying, cracks are generated and water leaks from the cracks, so that the water-blocking layer 2 cannot exhibit the water-blocking performance.

The present invention has been made in order to solve the above problems, and even when the amount of cement is reduced, it does not flow along the inclined surface when it is cast on the inclined surface, but reliably strikes the inclined surface. In addition to being able to be installed, even if a crack occurs, the purpose is to exhibit water blocking performance over a long period of time.

[0013]

According to a first aspect of the present invention, there is provided a water-blocking structural material comprising a mixture of a soil material such as soil and gravel, a low water-permeable material, and a solidified material. , Fibers mixed.

According to a second aspect of the present invention, there is provided a water-blocking structural member.
A short fiber is used as the fiber.

According to a third aspect of the present invention, there is provided a water-blocking structural member.
A long fiber is used as the fiber.

According to a fourth aspect of the present invention, there is provided a water-blocking structural member.
Any of the above fibers such as polypropylene, nylon, polyvinyl chloride fiber, glass fiber, silicon carbide fiber, carbon fiber, ceramic fiber, steel fiber, polyester, cotton yarn, hemp, rayon, acetate fiber, silk thread, wool, etc. The material is used.

According to a fifth aspect of the present invention, there is provided a water impermeable structural member.
Fibers that decompose due to aging are used as the above fibers.

The impermeable structural member according to claim 6 of the present invention is
A biodegradable polymer fiber or a photo-degradable polyethylene fiber is used as the fiber.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1 FIGS. 1 to 3 are cross-sectional views showing an example of a water impermeable layer in which a water impermeable structural material according to Embodiment 1 of the present invention is applied to a deposition site.
The same reference numerals are used for the same components. In this case, 21
Is a water-impervious layer that is cast so as to cover the concave deposition portion 1a and has a smaller amount of cement than conventional in order to maintain the water-impervious performance. It is a short fiber polypropylene that supplements the initial strength immediately after casting. The amount of cement is reduced to about 50% as compared with the conventional example. Since the amount of cement is small, the initial strength immediately after the impermeable structural material of the impermeable layer 21 is insufficient, the polypropylene 22 is mixed to compensate for the initial strength.
By reducing the amount of cement, the amount of calcium ions that modify the bentonite 6 of the low water-permeable material decreases. With this small amount of calcium ions, some bentonite 6 is metamorphosed. However, as shown in FIG. 3, most of the fine particles of bentonite 6 contain water and can swell and close gaps through which water passes. 21 exerts water-blocking properties over a long period of time. Therefore, the water blocking performance of the water blocking layer 21 hardly deteriorates. The water-blocking sheet 3 is attached and laid on the water-blocking layer 21, and protective sand 4 for protection is put on the bottom 5 of the sheet 3 to block water.

In order to construct the water-blocking layer 21, sand and gravel as soil materials as main materials, powdery bentonite 6 as a water-blocking low-permeability material, and a small amount of cement are used as water-blocking structural materials. Then, short fiber polypropylene 22 is added to the water-blocking structural material, and the mixture is stirred and mixed by a mixer. Since the fibers are short fibers, the polypropylene 22 can be stirred without being entangled. The amount of the polypropylene 22 may be about 1% by weight based on the water-blocking structural material. As the short fiber polypropylene 22, one having a length of about 2 to 5 cm is employed. Since the length is short, even when the heavy equipment works on the water-blocking layer 21, the polypropylene 22 does not become entangled with the caterpillar of the heavy equipment.

The mixed water-impervious structural material is cast so as to cover the deposition portion 1a, and the water-impervious layer 21 is constructed. The water-blocking structural material is bonded to the soil material composed of sand and gravel by mixing the polypropylene 22, and has a stickiness, so that it is difficult to flow. Since the viscosity of the water-blocking structural material is increased by the polypropylene 22, the initial strength can be compensated. If this water-blocking structural material is cast on the slope 24, it can stay on the slope 24 without flowing. Therefore, a large amount of the water-blocking structural material of the water-blocking layer 21 can be continuously cast.

The cement of the impermeable layer 21 undergoes a pozzolanic reaction, solidifies in about one month, and develops strength. For long-term strength after solidification, only a small amount of cement needs to be added to the impermeable structure. This amount of cement is
^The required long-term strength is sufficiently exhibited with an addition amount of 200 kg or less per ³ . The amount of cement is reduced by less than half compared to the conventional case.

As shown in FIG. 4, when the water barrier layer 21 is dried and shrunk, cracks 25 are formed on the bottom 5. As shown in FIG. 5, the unmodified bentonite 6 of the impermeable layer 21 swells with water, enters the crack 25, and penetrates. Since the swollen bentonite 6 closes the crack 25, water does not leak through the crack 25. Therefore, even if the crack 25 occurs, the water-blocking layer 21 can exhibit water-blocking performance.

Since the polypropylene 22 has no water absorption, the polypropylene 22 itself does not serve as a water passage.

Fibers for supplementing the strength include, in addition to polypropylene 22, nylon, polyvinyl chloride fiber, glass fiber, silicon carbide fiber, carbon fiber, ceramic fiber, steel fiber, polyester, cotton yarn, hemp,
Any of rayon, acetate fiber, silk thread, hair, etc., or a mixture thereof may be used.

As the main soil material, locally generated soil generated when the ground 1 is excavated in a concave shape may be used. The locally generated soil is dried and sandy. This sandy locally generated soil is mixed with a water-impervious structural material by a mixer and poured into the water-impervious layer 21.
May be constructed.

When the water-impermeable layer 21 is to be cast, a large amount can be continuously cast. Therefore, it is not necessary to perform a plurality of shots, and the construction period can be shortened.

As described above, the impermeable structure material of the impermeable layer 21 includes:
Since the short fiber polypropylene 22 is added and mixed, it is combined with sand and gravel to become sticky and increase the viscosity of the water-blocking structural material. Since the viscosity is high, the initial strength immediately after the casting can be maintained, and even when the amount of cement is reduced, it does not flow when the casting is performed on the slope 24. Since the impermeable structural material does not flow, it can be continuously cast in large quantities. Further, since the amount of cement in the water impermeable layer 21 is smaller than that in the related art, the amount of bentonite 6 to be transformed is reduced. Therefore, most of the bentonite 6 can swell, and even if the crack 25 occurs, the bentonite 6 enters the crack 25 and blocks the water passage. Therefore, the water-blocking layer 21 can exhibit water-blocking performance for a long period of time.

Embodiment 2 FIG. In the first embodiment, the case where the water barrier layer 21 is constructed using the short fiber polypropylene 22 has been described. However, in the second embodiment, as shown in FIGS. The water-impermeable layer 27 may be constructed by spraying both the water-impermeable structure material 28 and the water-impervious structure material 28 at the same location and spraying them together. The long fibers are entangled in a ball shape when agitated and mixed, and thus are separately sprayed and mixed as described above. In this spraying, the polypropylene 26 is compressed with water 31 from the nozzle 30 so as to be mixed with the water-blocking structural material 28 when the water-blocking structural material 28 is mixed with the water-blocking structural material 28 when the compressed air is blown from the nozzle 29 to the deposition portion 1a. Is sprayed on the same portion of the deposition section 1a. When the polypropylene 26 is blown with the compressed air, the polypropylene 26 flies upward, so that a mixture containing the water 31 is blown. After spraying, the upper surface 32 of the water-blocking structural material 28 is smoothed by using a spatula or the like. After being smoothed, the impermeable sheet 3 is applied and laid, and the protective sand 4 is put on the bottom 5 of the impermeable sheet 3.
The impermeable layer 27 is constructed.

The long-fiber polypropylene 26 has a longer fiber length than the short-fiber polypropylene 22, and is more easily bonded to a soil material made of sand or gravel, so that the viscosity is further increased. For this reason, the water barrier layer 27 has a higher initial strength than the water barrier layer 21 mixed with short fibers, so that the required initial strength can be maintained even if the amount of cement is reduced. The length of the polypropylene 26 is about 5 cm or more. In addition, as shown in FIG. 8, you may make it spray the continuous fiber polypropylene 26a which has no break.

Similarly, when the water barrier layer 27 is dried and shrunk,
Cracks 25 occur at the bottom 5. However, the unmodified bentonite 6 swells with water and cracks 25
Get inside and penetrate. Since the swollen bentonite 6 closes the crack 25, the water-blocking layer 27 can exhibit water-blocking performance.

As described above, the impermeable structural member 28 of the impermeable layer 27
Since the long fiber polypropylene 26 is mixed, the viscosity is higher and the initial strength is higher than when the short fiber is mixed. Therefore, even if the slope 24 is further inclined, the water-blocking structural member 28 does not flow and can be cast. for that reason,
Even if the amount of cement is reduced, it can be continuously poured in a large amount without flowing when poured on the slope 24. In addition, impermeable layer 2
Since the cement amount of No. 7 is smaller than that of the related art, the amount of bentonite 6 to be transformed is reduced. Therefore, most of the bentonite 6 can swell. Even if the crack 25 occurs, the bentonite 6 penetrates into the crack 25, so that the water-blocking layer 21 can exhibit the water-blocking performance for a long period of time.

Embodiment 3 In the first embodiment, the case where the water barrier layer 21 is constructed using the short fiber polypropylene 22 has been described. However, in the third embodiment, as shown in FIG. The impermeable layer 34 may be constructed using the disappearing fibers 33. in this case,
As the fiber 33, a biodegradable polymer fiber which is an aliphatic polyester polymer compound is used. The biodegradable polymer fiber decomposes and disappears after the cement undergoes a pozzolanic reaction and solidifies.

After the cement has solidified and has developed long-term strength, as shown in FIG. 10, when the fibers 33 are decomposed, fine cavities 35 are formed. The bentonite 6 swells and penetrates into the cavity 35. Since the cavity 35 does not serve as a path for water, the water-blocking performance of the water-blocking layer 34 can be ensured. Since the fibers 33 are decomposed, the fibers 33 themselves do not become water passages, and the water blocking performance of the water blocking layer 34 does not decrease. Since the fibers 33 are melted, even if heavy equipment works on the impermeable layer 34, the fibers 33 do not become entangled with the caterpillars of the heavy equipment, and even if a bird stops on the impermeable layer 34, the feet may be entangled. There is no. In addition, as the fiber 33, a photodegradable polyethylene fiber or the like can be used in addition to the biodegradable polymer fiber.

As described above, the impermeable structure material of the impermeable layer 34 includes:
Since the fiber 33 which decomposes after the cement is solidified is used, a cavity 35 is formed after the fiber 33 is decomposed. The bentonite 6 swells and enters the cavity 35. Since the cavity 35 does not serve as a water passage, the water blocking performance of the water blocking layer 34 does not decrease. Therefore, even if the amount of cement is reduced, it can be continuously poured in large quantities without flowing when poured on a slope. Further, since the amount of cement in the impermeable layer 34 is smaller than in the conventional case, the amount of bentonite 6 to be transformed is reduced. Therefore, most of the bentonite 6 can swell, and the impermeable layer 34 can exhibit impermeable performance over a long period of time.

Not only powdery bentonite but also particulate bentonite having large grains may be used.

[0038] In addition to bentonite, low-permeability materials include
Kaolin or asphalt emulsion may be used. Although the present invention has been described with respect to the case of constructing the impermeable layer in the deposition site, the present invention is not limited to this, and the present invention is applied to the bottom and slopes of rivers and ponds of golf courses. Water leakage may be prevented, and the present invention may be applied underground in a desert to construct a dam underground in a desert.

[0039]

As described above, according to the first aspect of the present invention, there is provided a water-blocking structural material comprising a mixture of a soil material such as soil or gravel, a low water-permeable material and a solidified material. Even when the amount of cement is reduced, it does not flow along the inclined surface when cast on the inclined surface, it can be reliably cast on the inclined surface, and even if cracks occur, It can show water barrier performance.

According to the second aspect of the present invention, since short fibers are used as the fibers, even when the cement amount is reduced, the fibers do not flow along the inclined surface when they are cast on the inclined surface. ,
In addition to being able to be reliably cast on an inclined surface, even if cracks occur, it is possible to exhibit water blocking performance over a long period of time.

According to the third aspect of the present invention, since long fibers are used for the fibers, even if the amount of cement is reduced, the fibers do not flow along the inclined surface when cast on the inclined surface. ,
In addition to being able to be reliably cast on an inclined surface, even if cracks occur, it is possible to exhibit water-blocking performance for a long period of time, and it is also possible to drive on a further inclined surface.

According to the fourth aspect of the present invention, the fibers include polypropylene, nylon, polyvinyl chloride fiber, glass fiber, silicon carbide fiber, carbon fiber,
Since any fiber or mixed material such as ceramic fiber, steel fiber, polyester, cotton thread, hemp, rayon, acetate fiber, silk thread, wool, etc. was used, even when the cement amount was reduced, Not only do not flow along the inclined surface, but also can be reliably cast on the inclined surface, and even if a crack occurs, the water shielding performance can be exhibited for a long period of time.

According to the fifth aspect of the present invention, since the fibers which decompose with the lapse of time are used for the fibers, even when the cement amount is reduced, the fibers are formed along the inclined surface when the cement is cast on the inclined surface. In addition to being able to be poured on the inclined surface without flowing, the water-blocking performance can be exhibited for a long time even if a crack occurs, and the water-blocking performance can be exhibited without deteriorating the performance.

According to the sixth aspect of the present invention, since a biodegradable polymer fiber or a photo-degradable polyethylene fiber is used as the fiber, the fiber is cast on an inclined surface even if the amount of cement is reduced. Sometimes it does not flow along the inclined surface, it can be reliably cast on the inclined surface, and even if cracks occur, it can exhibit water blocking performance over a long period of time, and also exhibit water blocking performance without deteriorating performance be able to.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an artificial impermeable layer according to Embodiment 1 of the present invention.

FIG. 2 is a cross-sectional view illustrating a configuration of an artificial water-impervious layer according to the first embodiment.

FIG. 3 is a cross-sectional view illustrating a configuration of an artificial water-impervious layer according to the first embodiment.

FIG. 4 is a cross-sectional view showing cracks in the artificial impermeable layer according to the first embodiment.

FIG. 5 is a cross-sectional view showing cracks in the artificial impermeable layer according to the first embodiment.

FIG. 6 is a cross-sectional view showing a configuration of an artificial impermeable layer according to Embodiment 2.

FIG. 7 is a cross-sectional view illustrating a configuration of an artificial impermeable layer according to Embodiment 2.

FIG. 8 is a cross-sectional view showing a configuration of an artificial impermeable layer according to Embodiment 2.

FIG. 9 is a cross-sectional view illustrating a configuration of an artificial impermeable layer according to Embodiment 3.

FIG. 10 is a cross-sectional view illustrating a configuration of an artificial impermeable layer according to Embodiment 3.

FIG. 11 is a cross-sectional view showing a configuration of a conventional artificial water barrier layer.

FIG. 12 is a cross-sectional view showing a configuration of a conventional artificial water barrier layer.

FIG. 13 is a schematic diagram showing a crystal structure of bentonite.

FIG. 14 is a schematic view showing a crystal structure of bentonite.

FIG. 15 is a schematic view showing a crystal structure of bentonite.

FIG. 16 is a cross-sectional view showing a configuration of a conventional artificial water barrier layer.

[Explanation of Signs] 1 Ground, 1a sediment, 3 impermeable sheet, 4 protective sand, 5 bottom, 6 bentonite, 21 impermeable layer, 22
Polypropylene, 24 slopes, 25 cracks.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court (Reference) C04B 14:10 16:06 14:06) 111: 00 (72) Inventor Katsuei Nishiyama Tsukudo-cho, Shinjuku-ku, Tokyo No. 1 Kumagaya Gumi Tokyo Head Office (72) Inventor Naoto Hamada 2-1, Kumagaya Gumi Tokyo Head Office (72) Inventor Taku Ohori 2 Tsukudocho, Shinjuku-ku, Tokyo No. 1 Kumagaya Gumi Tokyo Head Office (72) Inventor Takahiro Shimizu 2-1 Kumagaya Gumi Tokyo Head Office, Shinjuku-ku, Tokyo 2-1 (72) Inventor Katsumi Mizuno 1-9-1 Edobori, Nishi-ku, Osaka-shi (72) Inventor Tadashi Hamako 8-14-14 Ginza, Chuo-ku, Tokyo Nippon Special Construction Co., Ltd. (72) Inventor Haruhito Takahashi 8-14-14 Ginza, Chuo-ku, Tokyo Nippon Special Construction stock (72) Inventor Yoji Kikuchi 8-14-14 Ginza, Chuo-ku, Tokyo Nittoku Construction Co., Ltd. F-term (reference) 2D018 DA00 4D004 AA46 BB04 4G012 PA06 PA24 PC13

Claims (6)

[Claims] 1. A water-blocking structural material comprising a mixture of a soil material such as soil or gravel, a low water-permeable material and a solidified material, wherein fibers are mixed. 2. The impermeable structure material according to claim 1, wherein short fibers are used as the fibers. 3. The impermeable structural member according to claim 1, wherein a long fiber is used as the fiber. 4. Polypropylene, nylon,
It is characterized by using any fiber or mixed material such as polyvinyl chloride fiber, glass fiber, silicon carbide fiber, carbon fiber, ceramic fiber, steel fiber, polyester, cotton thread, hemp, rayon, acetate fiber, silk thread, wool, etc. The water-blocking structural material according to claim 1 or claim 2 or claim 3. 5. The impermeable structural member according to claim 1, wherein a fiber that decomposes with the lapse of time is used as the fiber. 6. The waterproof material according to claim 5, wherein a biodegradable polymer fiber or a photo-degradable polyethylene fiber is used as the fiber.