JP2022044562A - Sandbag and sandbag manufacturing method - Google Patents

Abstract

To provide a sandbag which is lightweight, is easily transported, is excellent in shape followability, is simply disposed, and prevents degeneration even when stored over a long period of time.SOLUTION: A sandbag is obtained by filling the inside of a bag having water permeability with a filler composed of (A) 30 mass% or more and 80 mass% or less of porous ceramic having a grain size by sieve classification of 75 μm or less, and (B) a clastic material having a grain size by sieve classification of more than 75 μm. (B) The clastic material contains (B') a clastic material having a grain size by sieve classification of more than 75 μm and 1,000 μm or less, 20 mass% or more of (B') the clastic material is preferably contained in the total filler, and (B) the clastic material preferably contains a porous ceramic. In (A) the porous ceramic having the grain size by sieve classification of 75 μm or less, a pore of a micrometer order having a pore diameter of more than 10 nm and 1,000 nm or less and a pore of a micrometer order having a pore diameter of more than 1 μm and 70 μm or less preferably exist.SELECTED DRAWING: None

Description

Application for application of Article 30, Paragraph 2 of the Patent Act Nikkan Kogyo Shimbun Dated September 2, 2nd Issuer name: Nikkan Kogyo Shimbun Co., Ltd. Date of issue: September 2, 2nd Reiwa [Publications, etc.] Website Address: Described in the attached sheet Publication date: Described in the attached sheet [Publications, etc.] Hokugoku Shimbun Morning edition dated September 8, 2nd issue: Hokugoku Shimbun Co., Ltd. Publication date: September 8th, 2nd year [Published] [Publications, etc.] Construction Newspaper, September 9, 2nd year Issuer name: Nikkan Construction Newspaper Co., Ltd. Publication date: September 9, 2nd year, Reiwa [Publications, etc.] Website address: https: // www. nikkei. com / article / DGXMZO63633230Z00C20A9LB0000 / Publication date: September 9, 2nd year of Reiwa [Publications, etc.] Daily report of Chemical Industry, dated September 10, 2nd year of Reiwa Issuer name: Nikkei Co., Ltd. Publication date: 2nd year of Reiwa September 10 [Publications, etc.] Textile News Reiwa 2nd September 11th Publisher name: Daisen Co., Ltd. Publication date: Reiwa 2nd September 11th [Publications, etc.] Hokuriku Chunichi Shimbun Reiwa 2nd year Morning edition dated September 12, Publisher name: Chunichi Shimbun Co., Ltd. Publication date: September 12, 2nd year of Reiwa [Publications, etc.] Publication date: September 24, 2nd year of Reiwa [Publications, etc.] Nikkei Sangyo Shimbun, dated October 6, 2nd year of Reiwa Issuer name: Nihon Keizai Shimbun Co., Ltd. Publication date: October 6, 2nd year of Reiwa [Published] Materials, etc.] Non-woven fabric information No. 541 Publisher name: Non-woven fabric information Co., Ltd. Publication date: November 10, 2nd year of Reiwa [Publications, etc.] Hokkoku Shimbun Morning edition dated December 9, 2nd year of Reiwa Publisher: Hokkoku Co., Ltd. Newspaper company Publication date: December 9, 2nd year of Reiwa [Publications, etc.] Hokuriku Chunichi Shimbun Morning edition dated December 9, 2nd year of Reiwa Publisher name: Chunichi Shimbun Co., Ltd. Publication date: December 2nd year of Reiwa 9th [Publications, etc.] Hokkoku Shimbun, morning edition dated December 17, 2nd issue: Hokkoku Shimbun Co., Ltd. Publication date: December 17, 2nd year [Publications, etc.] Construction Newspaper, Reiwa 2nd year Date of December 17 Publisher: Nikkan Kensetsu Tsushin Shimbun Co., Ltd. Date of issue: December 17, 2nd year of Reiwa [Publications, etc.] Place of sale: Described in the attached sheet Sales date: Described in the attached sheet

The present invention relates to sandbags and a method for producing sandbags.

When a large amount of water flows out, such as flooding of a river, rupture of a water pipe due to an earthquake, or leakage of water from a water storage tank, put soil, gravel, mountain sand, etc. in a polyethylene bag to stop the flowing water. Filled sandbags have traditionally been used.

However, the soil in the bag is heavy and difficult to transport, and because it hardens when it absorbs water, it does not easily deform along the outer shape of the bag, allowing water to enter through the gaps between the sandbags that are lined up or stacked. There is a problem that will end up.

Therefore, in Patent Document 1, a modified polymer compound having high water absorption is supported in a water-permeable bag-like body by being supported by a flexible support, the weight during transportation is reduced, and the shape followability is achieved. Sandbags with are proposed.

JP-A-2002-275852

However, conventional sandbags filled with soil, gravel, mountain sand, etc. can be disposed of if the soil inside is taken out of the bag, but the sandbags proposed in Patent Document 1 use a water-absorbent polymer. Therefore, there is a problem that disposal of used sandbags requires treatment such as separation and incineration of the contents. In addition, soil containing organic matter and water-absorbing polymers have a problem that they rot and algae and mold grow during long-term storage.

Therefore, it is an object of the present invention to provide a sandbag that is lightweight, easy to carry, has excellent shape followability, is easy to dispose of, and is not easily deteriorated even after long-term storage.

In order to solve the above problems, the sandbag and the method for manufacturing sandbags according to the embodiment of the present invention have the following configurations.
The filler composed of (1) 30% by mass or more and 80% by mass or less of porous ceramics having a particle size of 75 μm or less by sieving classification and (B) debris having a particle size of more than 75 μm by sieving classification is water permeable. A sandbag that is filled in a bag with.
(2) The (B) debris contains debris having a particle size of more than 75 μm and 1000 μm or less due to (B') sieving, and the (B') debris is 20% by mass or more with respect to the entire filling. The sandbag according to (1) above, which is characterized by being contained.
(3) The sandbag according to (1) or (2) above, wherein the (B) debris contains porous ceramics.
(4) The porous ceramics having a particle size of 75 μm or less by the sieve classification (A) have nanometer-order pores having a pore diameter of more than 10 nm and 1000 nm or less and micrometer-order pores having a pore diameter of more than 1 μm and 70 μm or less. The earthen sac according to any one of (1) to (3) above, which is characterized by the above-mentioned.
(5) The permeability coefficient of the filling material measured according to the change water level permeability test described in JIS A1218: 2009 is 1.0 × ^10-5 cm / s or less, as described in (1). )-(4). The sandbag according to any one of the items.
(6) The sandbag according to any one of (1) to (5) above, wherein the bag is a woven fabric of natural fiber or biodegradable fiber.
(7) Firing a mixture containing clay and organic sludge to obtain (A) porous ceramics having a particle size of 75 μm or less by sieving.
Obtaining a filling consisting of (A) 30% by mass or more and 80% by mass or less of porous ceramics having a particle size of 75 μm or less by sieving classification and (B) debris having a particle size of more than 75 μm by sieving classification, and water permeability. Filling a bag with the property with the filling,
How to make sandbags, including.

Since the sandbag of one embodiment of the present invention contains porous ceramics having a small particle size and the content thereof is within a predetermined range, it is lightweight, has excellent shape followability, and does not easily form a lump even when it absorbs moisture. Therefore, it becomes easy to arrange and stack sandbags without gaps. In addition, the filling can be disposed of by simply spraying it on the surface of the earth, and has the effect of being resistant to deterioration even when stored for a long period of time.

Hereinafter, sandbags according to an exemplary embodiment of the present invention will be described, but the present invention is not limited to these embodiments.

The sandbag according to the present embodiment is filled with (A) 30% by mass or more of porous ceramics having a particle size of 75 μm or less by sieving, and (B) debris having a particle size of more than 75 μm by sieving. It is a sandbag filled in a bag having sex.

(Porous ceramics with a particle size of 75 μm or less by sieving classification)
The porous ceramics having a particle size of 75 μm or less according to (A) sieve classification of the present embodiment are ceramics composed of particles having a large number of pores in the particles and passing through a sieve having an opening of 75 μm.

As a raw material for ceramics, a mixture of clay and at least one selected from the group consisting of organic sludge, diatomaceous earth, and a foaming agent is used. Ceramics can be made porous by blending clay with one selected from the group consisting of organic sludge, diatomaceous earth, and a foaming agent and firing. In particular, a mixture containing at least clay and organic sludge from the viewpoint that nanometer-order pores having a pore diameter of more than 10 nm and 1000 nm or less and micrometer-order pores having a pore diameter of more than 1 μm and 70 μm or less can be easily formed in the obtained ceramics. It is good to bake.

Clay is a mineral material having clay-like properties that is generally used as a raw material for ceramics, and is other than diatomaceous earth. As the clay, known ones conventionally used for ceramics can be used, and the clay is composed of mineral compositions such as quartz, feldspar, or other clay-based materials. The constituent minerals are mainly kaolinite, halloysite, montmorillonite, and illite. , Bentonite or pyrophyllite is preferred. Among them, frog-eye clay and the like are preferable. The clay can be blended alone or in combination of two or more.

Organic sludge is sludge containing an organic substance as a main component. Any organic sludge can be used, and activated sludge derived from wastewater treatment of sewage or factories is preferable. Activated sludge is discharged from a wastewater treatment facility using the activated sludge method through agglomeration and dehydration steps. By using the organic sludge, nanometer-order pores and micrometer-order pores can be efficiently formed by the path when the organic matter of the organic sludge is burnt down in the firing step and vaporized from the fired body. Furthermore, activated sludge derived from wastewater treatment, which was positioned as waste, can be reused as a raw material. The water content of the organic sludge is, for example, preferably 5 to 90% by mass, more preferably 60 to 90% by mass, and 65 to 85% by mass with respect to the total mass of the organic sludge. Is even more preferable. Within the above range, mixing into the mixture is easy.

When organic sludge is used, the content of organic sludge in the mixture can be determined in consideration of the moldability of the mixture and the like, and is, for example, 0.1 to 30% by mass with respect to the total mass of the mixture. It is preferable, 5 to 20% by mass is more preferable, and 5 to 15% by mass is further preferable. When the content of the organic sludge in the mixture is within the above range, the mixture has appropriate fluidity and plasticity, and can be smoothly molded without clogging the molding apparatus.

The mixing device used in the mixing step of the mixture is not particularly limited, and a known mixing device can be used. Examples of the mixing device include a kneader such as a mix maller (manufactured by Shinto Kogyo Co., Ltd.), a kneader (manufactured by Moriyama Co., Ltd.), a mixer (manufactured by Nikko Kagaku Co., Ltd.), and the like.

The mixture may be formed into an appropriate shape such as a columnar shape, a plate shape, a granular shape, or a pellet shape by using a known molding apparatus such as a vacuum clay kneading machine, a flat plate press molding machine, and a flat plate extrusion molding machine. By firing such a molded product, a lump of porous ceramics can be obtained.

If necessary, the molded product may be dried before firing. The drying operation can be performed using a known method. For example, the molded product may be naturally dried at room temperature (for example, around 20 to 30 ° C. as a guide), or may be treated and dried in a hot air drying oven at 50 to 220 ° C. for an arbitrary time.

The firing step is not particularly limited, and a known method can be used. For example, there is a method of firing at an arbitrary temperature using a continuous sintering furnace such as a roller harskirun or a batch type sintering furnace such as a shuttle kiln. Above all, it is preferable to use a continuous sintering furnace for the firing operation from the viewpoint of productivity. The firing temperature (maximum temperature reached) can be determined according to the properties of the mixture and the like, and is, for example, 850 ° C to 1200 ° C. When the firing temperature is equal to or higher than the above lower limit, when organic sludge is used as the mixture to be fired, the odorous components derived from the organic sludge are thermally decomposed and eliminated, and most of the organic matter in the organic sludge is volatilized to reduce the weight. do. If it exceeds the above upper limit value, the entire structure of the ceramics may be vitrified and the pores may be blocked.

The ceramic obtained by the above step is a porous ceramic having a large number of pores. By becoming porous, the apparent density is reduced, the weight is reduced, and the transportability is improved. On the other hand, since a large amount of water can be contained in the ceramics, the weight during actual use increases and the sandbag should be able to withstand water pressure. Can be done. In general, when fine particles absorb moisture, they become a Bingham fluid that does not flow until a certain shear force (yield stress) is applied, but the fine particles that have taken in water into a large number of pores are fine particles that do not have pores. Compared with, the volume fraction of water is high, and it exerts the effect of reducing the yield stress. Therefore, a sandbag having high shape-following property can be obtained even after getting wet with water. The apparent density (bulk density) of the porous ceramics obtained by the above step may be, for example, 0.75 g / cm ³ or more and 1.0 g / cm ³ or less. Further, the BET specific surface area of the porous ceramics obtained by the above step may be, for example, 0.4 m ² / g or more and 2.0 m ² / g or less.

It is preferable that the porous ceramics have nanometer-order pores having a pore diameter of more than 10 nm and 1000 nm or less and micrometer-order pores having a pore diameter of more than 1 μm and 70 μm or less. Micrometer-order pores reduce the apparent density, while nanometer-order pores significantly improve the water retention rate due to capillarity, greatly increase the weight when absorbing water, and make sandbags that can withstand higher water pressure. Can be done.

The pore diameter can be measured by performing image processing according to the scale from the image data observed by the scanning electron microscope. Specifically, the pore diameter of the pores of the granular material is a value obtained by measuring the equivalent circle diameter of the pores existing on the surface of the granular material using an electron microscope.

The pores formed in the porous ceramics may be independent or may be communication holes that communicate with each other.

The porous ceramics obtained as described above may be in the form of a lump. In the present embodiment, for example, by crushing the lump and then classifying it, (A) porous ceramics having a particle size of 75 μm or less can be obtained by sieving classification. More specifically, the massive porous ceramics obtained by firing are crushed and crushed by a hammer mill, biaxial rotary crushing, jet mill, ball mill, edge runner mill, etc., and have a particle size of 75 μm or less. It is good to sift through. Further, it may be sieved, and large particles having a particle size of more than 75 μm may be pulverized again and sieved into particles having a particle size of 75 μm or less. In this way, it is possible to produce porous ceramics having a particle size of 75 μm or less by sieving classification. (A) For porous ceramics having a particle size of 75 μm or less by sieving classification, the lower limit of the particle size is not particularly limited as long as the porosity can be maintained, but it is easy to maintain the porosity and leaks from the texture of the bag. From the viewpoint of shaving, it is preferable to use one having a particle size of 5 μm or more by sieving.

(Grus)
The (B) debris of the present embodiment is not particularly limited, and various debris having a particle size of more than 75 μm by sieving, such as sand, gravel, and ceramics, is used. In particular, a pulverized product of the porous ceramics produced by the above method can also be used. You can also use things. (B) Since the debris contains porous ceramics, the apparent density is further reduced, the weight is reduced, and the transportability is improved. On the other hand, the ceramics can contain a large amount of water, so that they can be used in actual use. It can be made into a sandbag that is heavier and can withstand water pressure. (B) A part of the debris may be porous ceramics, but by using all of them as porous ceramics, the above effect can be further exerted.

Further, the (B) debris preferably contains debris having a particle size of more than 75 μm and 1000 μm or less by (B') sieving classification. For example, (B) debris may be gravel sieved to a particle size of more than 75 μm and 1000 μm or less by sieving, or (A) the result of sieving of porous ceramics having a particle size of 75 μm or less by sieving. The surplus generated may be further sieved using a sieve having an opening of 1000 μm or less. Since the (B) debris contains the (B') debris, the sandbag can be made to have even better shape followability.

(Filling)
The filler of the present embodiment is filled with (A) 30% by mass or more and 80% by mass or less of porous ceramics having a particle size of 75 μm or less by sieving, and (B) debris having a particle size of more than 75 μm by sieving. It is a thing. (A) By containing 30% by mass or more of fine particles having a particle size of 75 μm or less by sieving classification, a sandbag having high water stopping property can be obtained. Further, since the content of the fine particles is 80% by mass or less and the fine particles are porous ceramics, it is possible to prevent the debris from absorbing moisture and forming a lump, and there is no gap even in a wet sandbag. It becomes easy to arrange and stack. The amount of the porous ceramics having a particle size of 75 μm or less by (A) sieving classification in the packing may be 35% by mass or more or 40% by mass or more, and may be 75% by mass or less or 70% by mass or less. ..

The content of (B) debris in the packing of the present embodiment is not particularly limited. As described above, the (B) debris may contain debris having a particle size of more than 75 μm and 1000 μm or less by (B') sieving, and in this case, the (B') debris is filled. It may be contained in an amount of 20% by mass or more, 25% by mass or more, or 30% by mass or more with respect to the whole of the substance. Since the (B') debris is contained in an amount of 20% by mass or more based on the total amount of the filling, the sandbag can be made to have more excellent shape followability.

Further, the filling may be composed of (B) debris as the balance except (A), or (A) and (B) as long as the effect of the sandbag according to the present embodiment is not impaired. ) May be included. Specifically, the filling material may contain 1% by mass or less of other components other than (A) and (B) such as heat-treated cotton and sawdust.

Further, in the present embodiment, the hydraulic conductivity of the packing material measured according to the variable hydraulic conductivity test described in JIS A1218: 2009 is, for example, 1.0 × 10 ^-4 cm / s or less, 1.0 ×. It can be ^10-5 cm / s or less or 1.0 × ^10-6 cm / s or less. When the water permeability coefficient is 1.0 × 10 ^-4 cm / s or less, particularly 1.0 × 10 ^-5 cm / s or less, the sandbag can be made to have high water stopping property. As described above, the packing of the present embodiment (A) contains fine particles having a particle size of 75 μm or less by sieving classification in a predetermined amount or more, so that excellent water stopping property can be easily ensured.

(bag)
The bag of the present embodiment is not particularly limited as long as it is a bag having water permeability, and is made of a woven fabric, a knitted fabric, or a non-woven fabric made of natural fibers such as hemp and cotton and synthetic fibers such as polyethylene fibers. And so on. In particular, if it is a woven fabric of natural fibers or biodegradable fibers such as polylactic acid, polyhydroxybutyric acid, and poly (butylene adipate-co-butylene terephthalate), the used sandbags may be left on the ground surface as bags. By burying it in the soil, it can be disposed of, and it is possible to omit the process of taking out the filling in the bag and spraying it. Further, it is preferable to make the bag out of woven fabric because it has sufficient strength as a bag for sandbags and the outflow of fine particles to the outside of the bag can be suppressed. The material of the bag may be a sandbag that can be used repeatedly by using a highly durable synthetic fiber.

(Manufacturing method of sandbags)
The technique of the present disclosure also has an aspect as a method for manufacturing sandbags. That is, the method for manufacturing sandbags according to this embodiment is
A mixture containing clay and organic sludge is calcined to obtain (A) porous ceramics having a particle size of 75 μm or less by sieving.
Obtaining a filling consisting of (A) 30% by mass or more and 80% by mass or less of porous ceramics having a particle size of 75 μm or less by sieving classification and (B) debris having a particle size of more than 75 μm by sieving classification, and water permeability. Filling a bag with the property with the filling,
May be included. The effects of using organic sludge in the raw material mixture before calcination are as described above.

In addition, the method for manufacturing sandbags according to this embodiment is
A mixture containing clay and organic sludge is calcined to obtain a mass of porous ceramics, and
Crushing the lump to obtain porous ceramics having a particle size of 75 μm or less by (A) sieving classification.
May be included. By once obtaining a massive porous ceramic and then crushing it, it is easy to obtain a porous ceramic having a particle size of 75 μm or less by (A) sieving classification and having excellent homogeneity.

In addition, the method for manufacturing sandbags according to this embodiment is
The lump is crushed and separated into porous ceramics having a particle size of 75 μm or less by the sieve classification (A) and a surplus, and at least a part of the surplus has a particle size by the sieve classification (B). Use as debris larger than 75 μm,
May be included. In particular, it is preferable that the surplus used as the (B) debris is sieved using a sieve having an opening of 1000 μm or less. As described above, in the production method according to the present embodiment, the porous ceramics having a particle size of 75 μm or less by (A) sieving classification and (B) debris having a particle size of more than 75 μm by sieving classification are made of the same material. It is also possible to simplify the process by using the above.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the following description.

<Clay>
As the clay, frog-eye clay (produced in Gifu prefecture) was used.

<Organic sludge>
As the organic sludge, activated sludge discharged through a coagulation and dehydration steps from a wastewater treatment facility by the activated sludge method of a dyeing factory (Komatsu Matere Co., Ltd.) was used. The organic matter content (relative to solid content) of this activated sludge was 83% by mass, the water content was 85% by mass, and the average particle size was 2.6 μm.

<Effervescent agent>
Cast iron slag was used as the foaming agent. This cast iron slag is in the form of particles (sieving, diameter 10 mm or less) containing SiO ₂ , Al ₂ O ₃ , CaO, Fe ₂ O ₃ , FeO, MgO, MnO, K ₂ O and Na ₂ O as main components. Ductile cast iron slag.

<Diatomaceous earth>
As the diatomaceous earth, a diatomaceous earth that was used as a roof tile for a house and then discarded was crushed (particle diameter 0.1 mm to 1.2 mm) was used.

<Gravel>
Gravel with a particle size of 40 mm or less sold at a home center in Komatsu City, Ishikawa Prefecture (DCM Kahma 21 Komatsu store) was used.

<Mountain sand>
We used mountain sand sold at a home center (DCM Kahma 21 Komatsu store) in Komatsu City, Ishikawa Prefecture.

The physical property values were measured by the following methods.

<Particle size by sieving classification>
The particle size of the packing was 75 μm or less (small) after the sample was sieved and passed through a sieve with an opening of 75 μm, and passed through a sieve with an opening of 1000 μm without passing through a sieve with an opening of 75 μm. Those that did not pass through a sieve having an opening of 1000 μm were defined as those having a mesh size of more than 75 μm to 1000 μm or less (medium), and those having an opening of more than 1000 μm (large).

<Permeability coefficient (variable water level method)>
JIS A1218: 2009 Soil permeability test method The value measured according to the variable water permeability test was corrected to the value at a water temperature of 15 ° C, and the value was determined as the permeability coefficient. As the specimen, the maximum dry density of the sample was determined according to the soil compaction test method by JIS A1210: 2009 compaction, and the sample was compacted to 90% of the obtained maximum dry density.

<Apparent density>
The apparent density was calculated by putting a full filling in a 100 cc container made of stainless steel and measuring the mass.

<Confirmation of hole diameter>
The nanometer-order pores and the micrometer-order pores of the porous ceramics were confirmed by observing with an electron microscope (SEMEDX Type H type, manufactured by Hitachi High-Tech Co., Ltd.) at 100 to 10000 times.

<Water stop test>
One side of the side wall of the aquarium having a long side of 60 cm and a short side of 30 cm was excised, and a device was produced in which water flowed out from the cut portion. Subsequently, a test sandbag was placed on the cut side wall, 15 L of water was poured into the water tank, and the time until the amount of water leaked from the water tank reached 1 L was measured to evaluate the water stoppage. ..

<Shape followability>
Six sandbags were completely immersed in water, and after 5 minutes, they were withdrawn from the water, and the shape followability when they were installed in 3 × 2 stages without gaps was evaluated according to the following indexes.
◎: Can be installed without problems ○: Can be installed by deforming with force with hands or feet ×: Filling hardens, making it difficult to install without gaps

(Example 1)
A foaming agent (45.0% by mass), clay (22.5% by mass), organic sludge (10.0% by mass) and diatomaceous earth (22.5% by mass) were mixed to obtain a plastic mixture. Then, the obtained mixture was extruded into a cylinder having a diameter of 1.5 cm with a vacuum clay kneading machine and cut into a cylinder having a length of 3 cm to obtain a cylindrical molded body.

The obtained molded body was fired in a continuous sintering furnace under firing conditions of a firing temperature of 990 ° C. and a residence time of 10 minutes at the firing temperature. After firing, the obtained mass of porous ceramics was crushed with a hammer mill until the maximum particle size became 10 mm or less. Next, using a sieve, the particles were sieved to 75 μm or less (small), more than 75 μm to 1000 μm or less (medium), and more than 1000 μm (large) to obtain ceramic granules classified according to particle size.

Among the obtained ceramic granules, 43% by mass of those having a particle size of 75 μm or less (small) and 57% by mass of those having a particle size of more than 75 μm and 1000 μm or less (medium) were mixed to obtain a filler. .. The permeability coefficient of the obtained filler was 3.2 × 10 ^-7 cm / s, the apparent density was 0.89 g / cm ³ , and the porous ceramics of 75 μm or less (small) were observed using an electron microscope. It was confirmed that the porous ceramics have nanometer-order pores having a pore diameter of more than 10 nm and 1000 nm or less and micrometer-order pores having a pore diameter of more than 1 μm and 70 μm or less.

About 11 L (about 10 kg) of the obtained filler was filled in a bag in which cotton fabric was sewn into a bag having dimensions of about 10 cm × 20 cm × 90 cm to obtain a sandbag.

The obtained sandbag was lightweight and had excellent shape followability. The result of the water stoppage test was 1149 seconds. Furthermore, the mass of the sandbag after the water stoppage test is 15.4 kg, which is a sufficient weight to withstand the water pressure, and no lumps are generated in the bag, so that the shape followability is not impaired. Was there.

(Comparative Example 1)
As a filling generally used for sandbags, a filling in which gravel and mountain sand were mixed at the same mass was obtained. The particle size of the packing by sieving was 45% by mass for those having a size of 75 μm or less (small), 34% by mass for those having a size of more than 75 μm and 1000 μm or less (medium), and 21% by mass for those having a size of more than 1000 μm (large). The hydraulic conductivity was 1.1 × 10 ^-4 cm / s, and the apparent density was 1.71 g / cm ³ .

About 11 L (about 19 kg) of the obtained filler was filled in a bag in which cotton fabric was sewn into a bag having dimensions of about 10 cm × 20 cm × 90 cm to obtain a sandbag.

Since the sandbags obtained were heavy and inferior in shape followability, it took time and effort to install them in the test water tank without any gaps for water to leak. The result of the water stopping test was 180 seconds, which was inferior to the sandbag of the example. Further, the filling material is solidified in the wet bag, and the shape followability is further impaired by getting wet.

(Example 2 to Example 6, Comparative Example 2 to Comparative Example 5)
The porous ceramics used in Example 1 and Comparative Example 1 and the packing obtained by sieving from the mixture of gravel and mountain sand were filled in the bags also used in Example 1 and Comparative Example 1 to obtain sandbags. The compounding ratio and the evaluation results are shown in Table 1.

From the results shown in Table 1, the sandbags according to Examples 1 to 6 had a small water permeability coefficient, excellent water stopping property, low apparent density, light weight, and excellent shape followability. On the other hand, the sandbags according to Comparative Examples 1 to 5 did not have sufficient performance in terms of at least one of permeability coefficient, apparent density, water stopping property and shape followability. The results of Examples 1 to 6 and Comparative Examples 1 to 5 are as follows in more detail.

(About water stop test results)
From the comparison between Example 2 and Comparative Example 2, in order to secure the ability to stop water as sandbags (water stoppage test result), the proportion of porous ceramics (small) with a particle size of 75 μm or less is required to be 30% by mass or more. Is.

(About shape followability)
From the comparison between Example 1 and Comparative Example 4, when a non-porous debris (small) is used instead of the porous ceramics (small), the shape followability is deteriorated. Further, from the comparison between Examples 3 to 6 and Comparative Example 3, it is necessary to set the ratio of the porous ceramics (small) to 80% by mass or less in order to secure excellent shape followability. Further, from the comparison of Examples 3 to 6, the proportion of the porous ceramics (small) was set to 20% by mass or more and 80% by mass or less, and the debris having a particle size of 75 to 1000 μm (medium), particularly the porous ceramics (medium). By setting the ratio to 20% or more, the shape followability is further enhanced.

(About apparent density)
From the comparison between Examples 1 to 6 and Comparative Example 1, by using porous ceramics as the debris, the density is reduced and a light sandbag can be formed. In particular, from the comparison of Examples 3 to 6, by using porous ceramics (middle) as the debris (middle) having a particle size of 75 to 1000 μm, the density becomes smaller and the sandbag can be made lighter. Further, even if porous ceramics (middle) is used as the debris (middle), it does not affect the water stopping property so much.

In the above embodiment, a case where a mixture of clay, organic sludge, a foaming agent and diatomaceous earth is used as a raw material for the porous ceramics has been exemplified, but the technique of the present disclosure is not limited to this. Other raw materials may be used as long as porous ceramics can be obtained. However, according to the findings of the present inventor, when a mixture containing at least clay and organic sludge is used as a raw material for the porous ceramics, the pores and pore diameters on the order of nanometers having a pore size of more than 10 nm and 1000 nm or less are more than 1 μm. Porous ceramics having micrometer-order pores of 70 μm or less can be easily obtained.

Since the sandbag of one embodiment of the present invention contains porous ceramics having a small particle size and the content thereof is within a predetermined range, it is lightweight, has excellent shape followability, and becomes a lump even if it absorbs moisture. Since it is difficult, it is easy to arrange and stack sandbags without gaps. In addition, the filling can be disposed of by simply spraying it on the surface of the earth, and it is easy to handle because it has the effect of not easily deteriorating even after long-term storage.

Claims (7)

A bag containing (A) 30% by mass or more and 80% by mass or less of porous ceramics having a particle size of 75 μm or less by sieving, and (B) debris having a particle size of more than 75 μm by sieving, and a bag having water permeability. A sandbag filled inside. The (B) debris contains a debris having a particle size of more than 75 μm and 1000 μm or less by (B') sieving classification, and the (B') debris is contained in an amount of 20% by mass or more based on the total amount of the packing. Characteristic,
The sandbag according to claim 1. The debris (B) contains porous ceramics.
The sandbag according to claim 1 or 2. The porous ceramics having a particle size of 75 μm or less by the sieve classification (A) are characterized by having nanometer-order pores having a pore diameter of more than 10 nm and 1000 nm or less and micrometer-order pores having a pore diameter of more than 1 μm and 70 μm or less. do,
The sandbag according to any one of claims 1 to 3. The filler has a hydraulic conductivity of 1.0 × ^10-5 cm / s or less measured according to the variable hydraulic conductivity test described in JIS A1218: 2009.
The sandbag according to any one of claims 1 to 4. The bag is characterized by being a woven fabric of natural fibers or biodegradable fibers.
The sandbag according to any one of claims 1 to 5. A mixture containing clay and organic sludge is calcined to obtain (A) porous ceramics having a particle size of 75 μm or less by sieving.
Obtaining a filling consisting of (A) 30% by mass or more and 80% by mass or less of porous ceramics having a particle size of 75 μm or less by sieving classification and (B) debris having a particle size of more than 75 μm by sieving classification, and water permeability. Filling a bag with the property with the filling,
How to make sandbags, including.