JP5360734B2 - Soil covering material and method for producing covered soil using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a soil-covering material enabling production of cover soil returnable to nature and retaining herbicidal effect for a long time: and to provide a method for producing cover soil enabling production of homogeneous cover soil excellent in workability. <P>SOLUTION: The soil-covering material comprises (A) at least one selected from the group comprising earth and sand, crushed material and wasted material, (B) at least one selected from a group consisting of anhydride and gypsum hemihydrate, and (C) at least one selected from a group consisting of vinyl acetate resin and acrylic resin. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

  The present invention relates to a soil covering material and a method for producing a covering soil using the same.

  In modern urban spaces where construction materials such as concrete, glass, and bricks are used, the design incorporates nature, such as by placing trees on street trees and entrance gardens. Usually, in order to maintain such roadside trees and trees, weeds are removed. Here, as a method of removing weeds, a method of cutting weeds, a method of spraying a herbicide or preventing the growth of weeds, and the like are performed.

  However, the method of mowing weeds requires mowing work over time, and requires a lot of labor. In addition, the method of spraying herbicide has a problem that it generally leads to environmental pollution because herbicide is harmful.

  On the other hand, in order to prevent the growth of weeds, soil covering materials using insoluble construction materials such as hardened roadside trees and tree roots with concrete or covered with plastic sheets have been proposed.

  However, the soil covering material using the insoluble construction material has a problem that a great deal of labor is required for maintenance, treatment after use, and disposal, and there is also a disadvantage that the environmental aesthetic is impaired.

  Therefore, in recent years, soil covering materials using water-soluble construction materials instead of the insoluble construction materials have been studied. Since the soil covering material using this water-soluble construction material is composed of a material that can be reduced to the natural world, it has the advantage that maintenance, treatment after use, and disposal are unnecessary.

As a soil covering material using such a water-soluble construction material, for example, a gypsum-based structural material in which a gravel material and calcium sulfate (hemihydrate gypsum) are mixed and granulated has been proposed (Patent Document 1). reference). This gypsum-based structural material is cured by applying water to hydrate the hemihydrate gypsum to form dihydrate gypsum having excellent crystallinity. Moreover, as a construction method using this gypsum-based structural material, the gypsum-based structural material is laid on the soil surface to a thickness of about 2 to 10 cm, and water is sprayed from above to stiffen the gypsum-based structural material. A method of covering the surface has been proposed.
JP 2002-220273 A

  However, when the gypsum-based structural material described in Patent Document 1 is cured and used as a covered soil for covering the soil surface, the solubility of dihydrate gypsum contained in the covered soil is relatively low at 0.3%. Since it is large, dihydrate gypsum tends to be gradually eroded by water such as rainwater. If it does so, the mechanical strength will fall in the said covered soil for a short period, and it exists in the tendency which cannot continue the weeding effect for a long period of time. The covered soil means a hardened body of the soil covering material.

  Moreover, the construction method of the gypsum-based structural material described in Patent Document 1 is inferior in workability because it is necessary to lay the gypsum-based structural material on the soil surface by human power. Since the gypsum-based structural material is hardened by spraying water on the gypsum-based structural material after laying on the gypsum-based structural material, there is a possibility that water does not sufficiently penetrate into the gypsum-based structural material. In this case, the obtained coated soil is not sufficiently hardened to the internal gypsum-based structural material, and the mechanical strength tends to be uneven. Furthermore, since this coated soil has a tendency that the surface of the coated soil becomes uneven, water such as rainwater tends to accumulate in the recessed portions of the coated soil, and dihydrate gypsum in the coated soil is easily eroded by this water. There is a tendency. Then, this coated soil has insufficient mechanical strength locally, and as a result, it tends to be difficult to maintain the herbicidal effect for a long period of time.

  On the other hand, in the field of soil covering materials, as described above, there are many demands on soil covering materials that can be reduced to the natural world and can maintain the herbicidal effect for a long time. However, no soil covering material with sufficient characteristics has been found.

  The present invention has been made in view of the above circumstances, and is a soil covering material that can be reduced to nature and that can produce coated soil that can sustain a herbicidal effect for a long period of time, and has excellent workability and a uniform covering. It aims at providing the manufacturing method of the covering soil which can manufacture soil.

  In order to solve the above problems, the soil covering material of the present invention is at least one selected from the group consisting of (A) earth and sand, crushed material and waste material, and (B) at least selected from the group consisting of anhydrous gypsum and hemihydrate gypsum. And (C) at least one selected from the group consisting of a vinyl acetate resin and an acrylic resin.

  In the soil covering material, the component (B) is hydrated with water and becomes dihydrate gypsum excellent in crystallinity, so that the soil covering material is hardened and a covered soil is obtained. At this time, since the soil covering material contains the component (C), dissolution of dihydrate gypsum in the covered soil into water is suppressed. For this reason, the covering soil using such a soil covering material can maintain the herbicidal effect for a long period of time.

  Moreover, since the said (A)-(C) component in the said soil covering material can reduce | restore to the natural world, for example, when covering soil is applied, the covering soil using the said soil covering material is special. There is no need for maintenance or disposal / use after use.

  As described above, the reason why the covered soil using the soil covering material of the present invention can suppress erosion by water such as rainwater is not clear, but the soil covering material of the present invention contains the component (C). Thus, the surface of the dihydrate gypsum is formed into a film by the component (C), and it is considered that dissolution of the dihydrate gypsum in water is suppressed. However, the factor is not limited to this.

  The content of the component (A) in the soil covering material is 50 to 80% by mass, the content of the component (B) is 10 to 50% by mass, and the content of the component (C) is 1 to 30% by mass. % Is preferred.

  In the covered soil obtained using the soil covering material in this case, dissolution of dihydrate gypsum in the covered soil is further suppressed, and the herbicidal effect can be maintained for a longer period of time.

  The soil covering material preferably further contains (D) a setting retarder. Since this soil covering material further contains the component (D), when the soil covering material and water are mixed, the rate at which the component (B) contained in the soil covering material hardens and becomes dihydrate gypsum is delayed. Is done. That is, the rate at which the soil covering material hardens and becomes covered soil is delayed. As a result, when a soil covering material that does not contain water is laid at a predetermined position, the soil covering material is hydrated with moisture such as water vapor in the air to form a lump, and the laying is suppressed from becoming uneven. The

  Moreover, according to the said soil covering material, a soil covering material and water can be knead | mixed easily. That is, the soil covering material and water can be laid on the soil surface in a state of being previously kneaded. By this, not only the method of laying the soil covering material, spraying water from above to make the covered soil (watering coagulation method), but also mixing the soil covering material and water in advance and pouring it on the soil surface, The method of making it the covering soil by hardening can also be performed easily.

  Thus, when the above-mentioned soil covering material and water are mixed, it is not clear why the component (B) contained in the soil covering material is hydrated and the rate at which it becomes dihydrate gypsum is delayed. When the soil covering material of the present invention contains the component (D), the component (D) adheres to the surface of the component (B), which inhibits the hydration of the component (B) and forms dihydrate gypsum. It is thought that this is to suppress the crystal growth of dihydrate gypsum. However, the factor is not limited to this.

  The setting retarder is preferably at least one selected from the group consisting of sodium citrate, citric acid, calcium acetate, calcium oxalate and hydrates thereof.

  The method for producing coated soil according to the present invention includes a kneading step of kneading the above-described soil covering material and water to obtain a kneaded product, a laying step of laying the kneaded product at a predetermined position on the soil surface, and a kneaded product. And a curing step for curing.

  According to the method for producing a covered soil, since the above-described soil covering material is used, it is possible to produce a covered soil that can be reduced to the natural world and has a long-term herbicidal effect. Further, according to the method for producing a covered soil, since the soil covering material and water are kneaded, the kneaded product has fluidity, and the kneaded product can be easily poured onto the soil surface. become. If it does so, since a kneaded material can be laid uniformly on the soil surface, the covering soil obtained will have a homogeneous and flat surface structure. In addition, according to the method for producing a covered soil, the covered soil can be easily and quickly produced, and thus the workability is excellent.

  ADVANTAGE OF THE INVENTION According to this invention, the soil covering material which can reduce to nature, and can manufacture the covering soil which can maintain a herbicidal effect for a long period of time, and the manufacturing method of the covering soil which is excellent in workability and can manufacture a uniform covering soil Can be provided.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as necessary. However, the present invention is not limited to the following embodiments. In addition, the dimensional ratio of drawing is not restricted to the ratio of illustration.

  The soil covering material of the present invention comprises (A) at least one selected from the group consisting of earth and sand, crushed materials and waste materials, (B) at least one selected from the group consisting of anhydrous gypsum and hemihydrate gypsum, and (C) acetic acid. And at least one selected from the group consisting of vinyl resins and acrylic resins.

  The soil covering material of the present invention containing the components (A) to (C) can be coated soil by curing the component (B), and the soil covering material further contains the component (C). Therefore, the obtained coated soil can maintain the herbicidal effect for a long period of time.

  Moreover, since the (A) to (C) components in the soil covering material can be reduced to the natural world, for example, when the covered soil is constructed, the above-mentioned covered soil has a special maintenance or treatment / use treatment. No disposal is necessary.

  Next, each component will be described in more detail.

(A component)
The component (A) contained in the soil covering material according to the present invention is a main component of the soil covering material, and exhibits a function as an aggregate for improving durability.

  In the present invention, the component (A) (hereinafter also referred to as “aggregate”) is at least one selected from the group consisting of earth and sand, crushed material, and waste material. Here, the above earth and sand means clay, silt, sand, gravel, mud, gravel, or any mixture thereof. The crushed material means concrete, asphalt, brick, stone or the like obtained by artificially crushing stone, and concrete, asphalt, etc. fall under this category. Further, the waste material means industrial waste, and includes construction waste material, mines, rubble, wooden waste material, plastic chip, and the like. These may be used alone or in combination of two or more.

  Among these, it is preferable to use sand as an aggregate. When sand is used, the sand is easy to mix with the component (B) or the component (C), and therefore, it is excellent in handleability. Moreover, since sand is more compatible with soil than the other aggregates described above, it is more suitable from the viewpoint of reduction to the natural world.

  Although the magnitude | size of the aggregate used by this invention can be defined according to the aggregate to be used, it is preferable that it is 1-50 mm, for example. When the size of the aggregate is less than 1 mm, compared to the case where the size is in the above range, the mechanical strength of the covered soil tends to be insufficient, and the size of the aggregate exceeds 50 mm. And compared with the case where a magnitude | size exists in the said range, it exists in the tendency for an aggregate to not fully be replenished to the space | gap between the crystals of dihydrate gypsum produced when a soil covering material is hardened. Moreover, when the aggregate is sand, the size of the sand is preferably 1 to 5 mm. The shape of the aggregate is not particularly limited.

  It is preferable that the content rate of (A) component in the said soil coating material is 50-80 mass%. When the content of the component (A) is less than 50% by mass, the mechanical strength of the covered soil tends to be insufficient as compared with the case where the content is in the above range. When the content rate exceeds 80% by mass, the soil covering material tends not to be sufficiently cured as compared with the case where the blending ratio is in the above range.

(B component)
The component (B) contained in the soil covering material (hereinafter also referred to as “gypsum etc.”) is at least one selected from the group consisting of anhydrous gypsum and hemihydrate gypsum. By applying water, such gypsum and the like are hydrated into dihydrate gypsum as shown in the following chemical reaction formula.
CaSO ₄ · 1 / 2H ₂ O (half water gypsum) + 3 / 2H ₂ O → CaSO ₄ · 2H ₂ O (dihydrate gypsum)
CaSO ₄ (anhydrous gypsum) + 2H ₂ O → CaSO ₄ .2H ₂ O (dihydrate gypsum)

  Thus, since dihydrate gypsum obtained by hydrating gypsum and the like is excellent in crystallinity, when water is applied to the soil coating material containing gypsum and the like, the soil coating material is cured.

  Examples of the anhydrous gypsum include high temperature type anhydrous gypsum, insoluble anhydrous gypsum, anhydrite, soluble anhydrous gypsum, γ gypsum, and drying gypsum. Among these, soluble anhydrous gypsum, γ gypsum, or drying gypsum is preferable. In this case, anhydrous gypsum can be more reliably hydrated to form dihydrate gypsum. Further, the crystal system of the anhydrous gypsum may be any of a type I crystal system, a type II orthorhombic crystal, or a type III hexagonal crystal.

  As the above-mentioned hemihydrate gypsum, α-type gypsum, hard gypsum, hard hemihydrate gypsum, high-strength calcined gypsum, or α-type hemihydrate gypsum called hard gypsum, β gypsum, calcined gypsum, ordinary gypsum, or cast gypsum Β-type hemihydrate gypsum and the like. Examples of the crystal system of the hemihydrate gypsum include trigonal crystals.

  The soil covering material of this invention should just contain at least any one of the said anhydrous gypsum and hemihydrate gypsum. Among these, it is preferable to use hemihydrate gypsum alone. Hemihydrate gypsum is more easily hydrated than anhydrous gypsum and surely becomes dihydrate gypsum, so that the soil covering material can be reliably cured.

  It is preferable that the content rate of (B) component in the said soil coating material is 10-50 mass%. When the content rate of (B) component is less than 10 mass%, compared with the case where content rate exists in the said range, it exists in the tendency which cannot fully harden a soil coating material, and the content rate of (B) component is 50. When the content exceeds mass%, the mechanical strength of the coated soil tends to be insufficient as compared with the case where the content is in the above range.

(C component)
The component (C) contained in the soil covering material (hereinafter also referred to as “resin etc.”) is at least one selected from the group consisting of vinyl acetate resins and acrylic resins. By containing these compounds in the soil covering material, the dissolution of dihydrate gypsum in the formed covered soil into water such as rainwater is suppressed. From this, the soil covering material of this invention containing the said (C) component can extend the period which can sustain the weeding effect which was 1 to 2 years conventionally to 2 to 4 years.

  Examples of the vinyl acetate resin include polyvinyl acetate and vinyl acetate-ethylene copolymer, and examples of the acrylic resin include acrylate copolymer and styrene acrylic copolymer.

  Among these, it is preferable to use an acrylic resin. In this case, the herbicidal effect of the covered soil can be maintained for a longer period.

  The resin or the like may be hydrophilic or hydrophobic. However, if the surface of the dihydrate gypsum is made hydrophobic, the dissolution rate of the dihydrate gypsum in water can be delayed compared to the case where the surface of the dihydrate gypsum is hydrophilic. The resin or the like is preferably hydrophobic. Here, in the present invention, “hydrophilic” means a substance that is completely soluble in water, and “hydrophobic” means a substance that is not completely soluble in water.

  The resin and the like are preferably solid at room temperature from the viewpoint that they can be mixed uniformly. In addition, the shape of the resin or the like in this case is not particularly limited, and examples thereof include powder, granule, granule, lump, fiber, and colloid. Among these, it is preferable that it is powdery, granular, and colloidal.

  The weight average molecular weight of the resin or the like is preferably 100,000 to 1,000,000. When the weight average molecular weight of the resin or the like is within the above range, the coating effect of dihydrate gypsum can be further improved.

  It is preferable that the content rate of (C) component in the said soil coating material is 10-30 mass%. When the content rate of the component (C) is less than 10% by mass, it tends to be difficult to sufficiently delay the dissolution rate of dihydrate gypsum in water as compared with the case where the content rate is in the above range. When the content of the component (C) exceeds 30% by mass, the component (C) tends to remain when the soil covering material is reduced to the natural world as compared with the case where the content is in the above range. .

  Moreover, it is preferable that the mixture ratio of (C) component with respect to 100 mass parts of said (A) component is 1-5 mass parts. In this case, a resin or the like can be sufficiently uniformly mixed with gypsum or the like.

(Other ingredients)
The soil covering material of the present invention may contain the following components.

(D component)
Component (D) is a setting retarder. By including this setting retarder, even if the soil covering material contains water, gypsum and the like are hydrated, and the rate at which dihydrate gypsum is formed is delayed. For example, conventionally, when hemihydrate gypsum and water are kneaded, hemihydrate gypsum hydrates and hardens after 2 to 3 minutes, whereas in the soil covering material of the present invention, gypsum and the like are water after 30 to 90 minutes. Softens and hardens.

  Therefore, in this case, since it is possible to mix the soil covering material and water in advance, not only the method of laying the soil covering material and spraying water from the soil covering method (watering coagulation method), but also the soil covering material in advance. It is also possible to construct coated soil on the soil surface by mixing water and water and pouring the soil surface.

  Examples of the component (D) include sodium citrate, citric acid, calcium acetate, calcium oxalate, and hydrates thereof. These may be used alone or in combination of two or more. In addition, these compounds do not affect the solubility with respect to the water of the dihydrate gypsum mentioned above.

  Among these, it is more preferable to use sodium citrate, citric acid, or a hydrate thereof. In this case, the rate at which gypsum or the like hydrates to form dihydrate gypsum can be further delayed.

  In addition to these, as a setting retarder, a fluorine compound or the like, an additive that generates calcium ions and an insoluble compound, or the like may be used. Examples of the fluorine-based compound include silicic acid silicate and sodium fluoride.

  When the soil covering material of the present invention contains a setting retarder, the content of the setting retarder in the soil covering material is preferably 0.1 to 0.5% by mass, More preferably, it is 0.3 mass%. When the content of the setting retarder is less than 0.1% by mass, the rate at which gypsum and the like hydrate and become dihydrate gypsum can be sufficiently delayed as compared with the case where the content is in the above range. When the content of the setting retarder exceeds 0.5% by mass, the time for completing the setting becomes longer and the workability tends to be inferior compared with the case where the content is within the above range. It is in.

(Surfactant)
The soil covering material of the present invention may contain a surfactant. In this case, the growth of the dihydrate gypsum crystal described above can be further promoted. Then, the covered soil has a larger crystal structure of dihydrate gypsum, and can delay the dissolution rate of dihydrate gypsum in water such as rainwater. Moreover, when a surfactant is contained in the soil covering material, the surface of the dihydrate gypsum is smoothed, and the residence time of water such as rain water on the dihydrate gypsum surface can be shortened. Then, the dissolution rate of dihydrate gypsum in water such as rainwater can be delayed. Furthermore, since dihydrate gypsum is hydrophilic, when a surfactant is included in the soil covering material, the hydrophilic groups of the surfactant are adsorbed on the dihydrate gypsum, and the hydrophobic groups are directed to the opposite side of the dihydrate gypsum. The surface of the dihydrate gypsum adsorbed with the surfactant can be made hydrophobic.

  Examples of the surfactant include diammonium phosphate, ammonium sulfate, sodium dodecylbenzenesulfonate, sodium dodecylsulfate, and the like. These may be used alone or in combination of two or more.

  Among these, it is preferable to use ammonium sulfate and diammonium phosphate. In this case, calcium phosphate having a low solubility is produced, so that the particle size of the produced dihydrate gypsum increases. Thereby, the solubility of dihydrate gypsum can be reduced.

  Moreover, it is preferable to use sodium dodecylbenzenesulfonate and sodium n-dodecylsulfate. In this case, since the crystal particles of dihydrate gypsum become larger and the surface area of each crystal becomes smaller, the solubility of dihydrate gypsum in water can be reduced.

  When the soil covering material of this invention contains surfactant, it is preferable that the content rate of surfactant in the said soil covering material is 0.01-0.3 mass%. When the content of the surfactant is less than 0.01% by mass, it tends to be difficult to sufficiently achieve the above effects as compared with the case where the content is in the above range. Moreover, even if the content rate of surfactant exceeds 0.3 mass%, the improvement of the effect obtained is not recognized compared with the case where content rate exists in the said range.

(filler)
The soil covering material of the present invention may contain a filler. In this case, since the filling density of the solid content is improved by the dihydrate gypsum and the filler of the soil covering material, the intrusion of water such as rainwater can be suppressed.

  Examples of the filler include colloidal silica and sodium oxide. Among these, it is preferable to use colloidal silica from the viewpoint that a small amount of water that has entered the soil covering material can be adsorbed. In addition, these may be used individually by 1 type and may be used in mixture of 2 or more types.

  When the soil covering material of this invention contains a filler, it is preferable that the content rate of the filler in the said soil covering material is 5-30 mass%. When the content of the filler is less than 5% by mass, it tends to be difficult to sufficiently suppress the intrusion of water into the covered soil as compared with the case where the content is in the above range. Moreover, even if the content rate of a filler exceeds 30 mass%, compared with the case where a content rate exists in the said range, the improvement of the effect obtained is not recognized.

(Other resins)
The soil covering material of the present invention may further contain other resins. In this case, since the dihydrate gypsum is further coated with another resin, dissolution of the dihydrate gypsum with water such as rainwater can be further suppressed.

  As said other resin, biodegradable plastics, such as a polylactic acid resin, polyvinyl alcohol, etc. are mentioned. Among these, it is preferable to use a biodegradable plastic such as a polylactic acid resin from the viewpoint of being environmentally friendly. In addition, these may be used individually by 1 type and may be used in mixture of 2 or more types.

  When the soil covering material of this invention contains other resin, it is preferable that the content rate of the other resin in the said soil covering material is 1-30 mass%. When the content of other resins is less than 1% by mass, it tends to be difficult to sufficiently suppress the dissolution of dihydrate gypsum in water as compared with the case where the content is in the above range. . Moreover, even if the content rate of other resin exceeds 30 mass%, the improvement of the effect obtained is not recognized compared with the case where content rate exists in the said range.

  Since the covered soil obtained by curing the soil covering material of the present invention has a herbicidal effect for a long period of time, it covers the soil in which roadside trees and entrance garden trees are planted, especially outdoors. Is preferably used.

  Next, the manufacturing method of the covering soil using the soil covering material of this invention is demonstrated. The method for producing coated soil according to the present invention includes a kneading step of kneading the above-described soil covering material containing the components (A) to (D) and water to obtain a kneaded product, A laying step of laying in position, and a curing step of curing the kneaded product.

  Hereinafter, each step will be described in more detail.

(Kneading process)
First, in the method for producing a soil covering material of the present invention, the soil covering material containing the components (A) to (D) described above and water are kneaded to obtain a kneaded product. In addition, you may make this kneaded material contain surfactant, a filler, etc. as needed. Moreover, when this kneaded material is kneaded, for example, a kneader such as a Banbury mixer or a kneader that is a mixer for civil engineering construction is used.

  At this time, it is preferable to contain 60-170 mass parts of water with respect to 100 mass parts of hemihydrate gypsum, and it is more preferable to include 60-100 mass parts of water. When the content of water is less than 60 parts by mass, the fluidity of the kneaded product tends to be insufficient as compared with the case where the content is in the above range, and when the content exceeds 170 parts by mass, Compared to the case where the content is in the above range, the mechanical strength of the covered soil tends to be insufficient.

  The viscosity of the kneaded product is preferably 100 to 1000 cps. When the viscosity is less than 100 cps, the mechanical strength of the coated soil tends to be insufficient as compared with the case where the viscosity is in the above range. When the viscosity of the kneaded material exceeds 1000 cps, the viscosity is within the above range. Compared to a certain case, it becomes difficult to pour the kneaded material onto the soil surface, so that the covered soil tends to be non-uniform. The viscosity of the kneaded product is preferably maintained for 1 to 2 hours.

(Laying process)
Then, the kneaded material is laid at a predetermined position on the soil surface. In the present invention, in order to form a uniform covered soil at a predetermined position on the soil surface, a method is used in which a soil covering material and water are mixed in advance to form a kneaded product, and the kneaded product is poured onto the soil surface. Here, the predetermined position is not particularly limited as long as it is a place where the herbicidal effect is desired. In addition, when pouring a kneaded material, you may provide the frame which has fixed height on the outer edge of a predetermined position so that a kneaded material may not protrude from a predetermined position. The frame at this time may be a wooden frame or a concrete frame.

(Curing process)
Then, after laying the kneaded material, it is allowed to stand as it is, so that gypsum and the like are gradually hydrated to form dihydrate gypsum, thereby producing a covered soil in which the soil covering material is hardened.

  Thus, according to the method for producing coated soil of the present invention, since the above-described soil coating material is used, it is possible to produce coated soil that can be reduced to the natural world and can maintain the herbicidal effect for a long period of time. Further, according to the method for producing a covered soil, since the soil covering material and water are kneaded, the kneaded product has fluidity, and the kneaded product can be easily poured onto the soil surface. become. If it does so, since a kneaded material can be laid uniformly on the soil surface, the covering soil obtained will have a homogeneous and flat surface structure. In addition, according to the method for producing a covered soil, the covered soil can be easily and quickly produced, and thus the workability is excellent.

  Next, the construction method of the covering soil of this invention is demonstrated.

  FIG. 1 is a cross-sectional view showing an embodiment of a roadside tree in which the covered soil of the present invention is constructed. As shown in FIG. 1, a roadside tree constructed with the covered soil of the present invention includes a hole 8 having a predetermined shape, a soil 3 filled in the hole 8, a tree 1 planted in the soil 3, a soil 3 is provided with a covered soil 2 laid on the surface 3a of 3 and a concrete frame 5 provided at the peripheral edge of the covered soil 2. The soil 3 in which the tree 1 is planted is housed in the hole 8, and the covered soil 2 is laid on the surface 3 a of the soil 3 so as to cover the entire surface 3 a of the soil 3. At this time, the shape of the hole 8 is not particularly limited. Moreover, it is preferable that the hole 8 has a sufficient size so that the tree 1 can be planted. As for the concrete frame 5 provided in the peripheral part of the said covering soil 2, the lower part of the concrete frame 5 is embed | buried below from the ground surface, and is being fixed reliably by this. Furthermore, the concrete frame 5 has an upper end 5 a protruding above the surface 2 a of the covered soil 2 so that the covered soil 2 does not protrude from the concrete frame 5. Here, the shape of the concrete frame is not particularly limited, but is preferably annular.

  The roadside tree having such a structure is constructed as follows.

  First, a hole 8 is provided at a place where a roadside tree is to be installed. Then, the soil 3 and the tree 1 are installed inside the hole 8. At this time, it is preferable that the tree 1 is installed at the approximate center of the hole 8 in consideration of the growth of the root portion. Moreover, when installing the tree 1 and the soil 3 inside the hole 8, in order to fix the tree 1, the soil 3 is further added inside the hole 8, and the inside of the hole 8 is filled with the soil 3. In addition, after filling the inside of the hole 8 with the soil 3, in order to fix the tree 1 reliably, you may press the surface 3a of a soil with a plate compactor etc. At this time, the soil surface 3a is preferably flat. If it does so, when pouring a kneaded material into the soil surface, a kneaded material can be laid uniformly. In addition, when there are obstacles such as stones on the soil surface, it is preferable to remove them, but if they are small stones, they may be applied as they are.

  Next, the concrete frame 5 is provided. The concrete frame 5 is provided so as to surround the periphery of the position where the covered soil 2 is to be provided. Moreover, in order to fix the said concrete frame 5 reliably, a part below the concrete frame 5 is embed | buried below from the ground surface.

  Then, the kneaded material described above is poured into the surface 3 a of the soil 3 surrounded by the concrete frame 5. In addition, after pouring a kneaded material, it is preferable to arrange so that it may become uniform thickness and a smooth surface with a gold trowel etc. And by leaving this kneaded material to stand, the kneaded material is hardened and the covered soil 2 is formed. In addition, when the tree 1 is installed, it is preferable to provide a certain gap between the tree 1 and the covered soil 2. After the kneaded material is hardened and covered soil 2, the infiltration of rainwater and the like is reduced. Therefore, by providing a gap as described above, water permeates into the soil 3 from the gap and is sufficient for the root of the tree 1. Water is added to the water. Furthermore, when there is a possibility that the trunk portion of the tree 1 in contact with the covered soil 2 will grow greatly, providing the gap as described above prevents the covered soil 2 from hindering growth. .

  In addition, as a method of providing the gap, for example, by installing a spacer in advance between the tree 1 and the covered soil 2, after pouring the kneaded material to make the covered soil 2, by removing the spacer, It is possible to provide.

  The coated soil 2 preferably has a thickness of 1 to 5 cm. In this case, the herbicidal effect is sufficiently exhibited, and after a long period of use, it can be reliably reduced to the natural world.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment.

For example, in the above-described embodiment, the concrete frame 5 is embedded below the ground surface, but the concrete frame 5 may be installed on the ground surface without being embedded. Alternatively, the concrete frame may be box-shaped, embedded in the hole 8, and the soil 3 in which the tree 1 is planted may be accommodated. In this case, the concrete frame is preferably designed to have a sufficient size so as not to hinder the growth of the root portion of the tree 1.
Furthermore, if the kneaded material can be laid at a predetermined position, the concrete frame is not necessarily provided. Moreover, when a frame impairs aesthetics, after laying a kneaded material and making it the covering soil 2, you may remove a concrete frame. Moreover, a tree is not necessarily required and you may construct the covering soil of this invention on the soil surface without a tree.

EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example. In addition, in a present Example, a water mixing rate means the value calculated | required by a following formula.
Water mixing ratio = amount of water × 100 / amount of half-water gypsum The half-water gypsum in this example is obtained by calcining desulfurized gypsum, which is a by-product from the SOx recovery process of a thermal power plant.

Example 1
A coated soil was prepared using a kneading and coagulation method. That is, in a wooden frame of 4.7 × 14.8 × 2.0 cm, 100 g of hemihydrate gypsum, 150 g of sand, clear coat agent (acrylic acid ester copolymer (water-soluble milky white emulsion), manufactured by Intercept Co., Ltd. , Trade name) 6g and sodium citrate dihydrate 0.18g, put a soil covering material, add water further so that the water content is 60%, knead the resulting mixture To obtain a kneaded product.

And by leaving this kneaded material to stand, the hemihydrate gypsum was hydrated and the soil covering material was hardened. Then, it was dehydrated and dried in a dryer at 40 ° C., and the wooden frame was removed to obtain a test piece of coated soil. The obtained coated soil had a density of 1.6 g / cm ³ .

(Example 2)
A coated soil was obtained in the same manner as in Example 1 except that the clear coat agent used in Example 1 was changed to 12 g. The obtained coated soil had a density of 1.3 g / cm ³ .

(Example 3)
The clearcoat agent used in Example 1 was 10 g, sodium citrate dihydrate was 0.08 g, and Mighty 150 (Naphthalenesulfonic acid formalin condensate (density 1.190 to 1.210 g / cm ³ )). , Manufactured by Kao Corporation, trade name) 2.5 g was added to the soil covering material, and the coated soil was treated in the same manner as in Example 1 except that water was added so that the water mixing ratio was 50%. Obtained. The obtained covered soil had a density of 1.8 g / cm ³ .

Example 4
Implemented except that 6 g of wood bond (vinyl acetate (49%) (emulsion), density 1.06 g / cm ³ , trade name, manufactured by Konishi Co., Ltd.) was used instead of the clear coat agent used in Example 1. A covered soil was obtained in the same manner as in Example 1. The obtained covered soil had a density of 1.55 g / cm ³ .

(Example 5)
A coated soil was obtained in the same manner as in Example 1 except that 12 g of wood bond was used instead of the clear coat agent used in Example 1. The obtained coated soil had a density of 1.61 g / cm ³ .

(Example 6)
Similar to Example 1 except that 0.06 g of sodium citrate dihydrate used in Example 1 was used and 10 g of wood bond and 2.1 g of Mighty 150 were used instead of the clear coat agent. A coated soil was obtained. The obtained coated soil had a density of 1.67 g / cm ³ .

(Example 7)
Covered soil was prepared using the watering condensation method. That is, a soil covering material composed of 100 g of hemihydrate gypsum, 150 g of sand, and 6 g of clear coat agent is laid in a wooden frame of 4.7 × 14.8 × 2.0 cm, and water is mixed from above. Water was sprayed so that the water ratio became 60%, the water hydrated gypsum was hydrated, and the soil covering material was cured. Then, it was dehydrated and dried in a dryer at 40 ° C., and the wooden frame was removed to obtain a test piece of coated soil. The obtained coated soil had a density of 1.62 g / cm ³ .

(Example 8)
A coated soil was obtained in the same manner as in Example 7 except that the clear coat agent used in Example 7 was changed to 12 g. The obtained covered soil had a density of 1.66 g / cm ³ .

Example 9
A coated soil was obtained in the same manner as in Example 1 except that the clear coat agent used in Example 1 was changed to 3 g. The obtained covered soil had a density of 1.41 g / cm ³ .

(Example 10)
Implemented except that 3 g of CZ-126 (styrene acrylic copolymer resin (47 to 49%) (water-soluble milky white emulsion), manufactured by Konishi Co., Ltd.) was used instead of the clearcoat agent used in Example 1. A covered soil was obtained in the same manner as in Example 1. The obtained coated soil had a density of 1.47 g / cm ³ .

(Example 11)
A covered soil was obtained in the same manner as in Example 1 except that 6 g of CZ-126 was used instead of the clearcoat agent used in Example 1. The obtained coated soil had a density of 1.34 g / cm ³ .

(Example 12)
Other than using 3 g of CZ-250 (vinyl acetate-ethylene copolymer (water-soluble milky white emulsion), density 1.06, manufactured by Konishi Co., Ltd., trade name) instead of the clear coat agent used in Example 1. Covered the soil in the same manner as in Example 1. The obtained coated soil had a density of 1.68 g / cm ³ .

(Example 13)
A covered soil was obtained in the same manner as in Example 1 except that 6 g of CZ-250 was used instead of the clearcoat agent used in Example 1. The obtained coated soil had a density of 1.70 g / cm ³ .

(Example 14)
196 g of sand used in Example 1, 0.15 g of sodium citrate dihydrate, and 5 g of CZ-126 instead of clearcoat agent were used in the same manner as in Example 1 to cover the coated soil. Obtained. The obtained coated soil had a density of 1.77 g / cm ³ .

(Example 15)
A coated soil was obtained in the same manner as in Example 14 except that 10 g of CZ-126 used in Example 14 was used. The obtained covered soil had a density of 1.42 g / cm ³ .

(Example 16)
Example except that 0.2 g of sodium citrate dihydrate used in Example 14 was used, 6.7 g of CZ-126 was used, and water was added so that the water mixing ratio would be 80%. In the same manner as in Example 14, a coated soil was obtained. The obtained coated soil had a density of 1.52 g / cm ³ .

(Example 17)
A covered soil was obtained in the same manner as in Example 16 except that 6.7 g of CZ-250 was used instead of CZ-126 used in Example 16. The obtained coated soil had a density of 1.73 g / cm ³ .

(Example 18)
50 g of hemihydrate gypsum used in Example 1, 200 g of sand, 0.12 g of sodium citrate dihydrate, 4 g of CZ-126 instead of the clear coat agent, and the water mixing ratio A covered soil was obtained in the same manner as in Example 1 except that water was added so as to be 80%. The obtained covered soil had a density of 1.54 g / cm ³ .

(Example 19)
Example 18 is the same as Example 18 except that the sodium citrate dihydrate used in Example 18 is 0.18 g, 6 g of CZ-126 is used, and water is added so that the water mixing ratio is 120%. A covered soil was obtained in the same manner. The obtained coated soil had a density of 1.86 g / cm ³ .

(Comparative Example 1)
A coated soil was obtained in the same manner as in Example 1 except that the clear coat agent used in Example 1 was not used. The obtained coated soil had a density of 1.69 g / cm ³ .

(Comparative Example 2)
Add 0.15 g of sodium citrate dihydrate used in Example 1, no clear coat agent, 2.5 g of Mighty 150, and add water so that the water mixing ratio is 50%. A coated soil was obtained in the same manner as in Example 1 except that. The obtained coated soil had a density of 1.70 g / cm ³ .

(Comparative Example 3)
0.15 g of sodium citrate dihydrate used in Example 1 and 3 g of a commercially available laundry paste (polyvinyl alcohol (gel), manufactured by Permanent Glue Co., Ltd., trade name) instead of the clear coat agent, A covered soil was obtained in the same manner as in Example 1 except that 3 g of mighty 150 was used. The obtained coated soil had a density of 1.25 g / cm ³ .

(Comparative Example 4)
Instead of the sodium citrate dihydrate used in Example 1, 0.15 g of citric acid monohydrate was used, and no clear coat agent was used. Snowtex 30 (colloidal silica (30%) and sodium oxide (0 0.6%), and 12 g of a transparent sol (density 1.200 to 1.220 g / cm ³ ), manufactured by Nissan Chemical Co., Ltd., trade name) was used in the same manner as in Example 1 to obtain a covered soil. It was. The obtained coated soil had a density of 1.83 g / cm ³ .

(Comparative Example 5)
A coated soil was obtained in the same manner as in Example 7 except that the clear coat agent used in Example 7 was not used. The obtained covered soil had a mass of 251.1 g and a density of 1.55 g / cm ³ .

(Comparative Example 6)
The clear coat agent used in Example 7 was not used, and coated soil was obtained in the same manner as Example 7 except that 3 g of Mighty 150 was used. The obtained coated soil had a density of 1.67 g / cm ³ .

(Comparative Example 7)
The clear coat agent used in Example 7 was not used, and coated soil was obtained in the same manner as in Example 7 except that 12 g of Mighty 150 was used. The obtained coated soil had a density of 1.60 g / cm ³ .

(Comparative Example 8)
The clear coating agent used in Example 7 was not used, and coated soil was obtained in the same manner as Example 7 except that 12 g of laundry glue was used. The obtained coated soil had a density of 1.67 g / cm ³ .

(Comparative Example 9)
The same procedure as in Example 1 was used except that 3 g of PLASEMA L110 (polylactic acid resin (water-soluble milky white emulsion), manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name) was used instead of the clearcoat agent used in Example 1. Covered soil was obtained. The obtained coated soil had a density of 1.63 g / cm ³ .

[Evaluation method]
(Weather resistance test 1)
The weather resistance test 1 was conducted using the test pieces of the covered soil obtained in Examples 1 to 8 and Comparative Examples 1 to 8. First, in order to be able to irradiate and spray water on the 4.7 × 14.8 cm surface (upper part of the wooden frame) of these test pieces, put the test pieces on the Atlas Ci35A Xenon-ometer weather resistance tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.). Attached.

  In the first stage, light irradiation was performed for 200 hours under the condition of watering for 18 minutes in 2 hours, and subsequently, in the second stage, light irradiation was performed for 200 hours under the condition of watering for 30 minutes in 2 hours.

  Then, the mass of each test piece at the end of the first stage and the second stage was measured, and the amount of decrease in mass was calculated. The obtained results are shown in FIG.

  As shown in FIG. 2, in the kneading and condensing method, the clear coating agent (Examples 1 to 3) that is an acrylic resin or the wood bond (Examples 4 to 6) that is a vinyl acetate resin is used. It was found that the covered soil can greatly reduce the amount of mass loss. In particular, in the covered soil containing the clear coat agent, the amount of decrease in the mass of the covered soil is reduced by 45 to 50% in the first stage compared to the covered soil not containing the clear coat agent (Comparative Example 1). It was found that the amount of decrease in the mass of the covered soil was further reduced at the stage.

  On the other hand, in the covered soil not including the present invention including Mighty 150 (Comparative Example 2) which is a water reducing agent, Laundry glue (Comparative Example 3), and Snowtex 30 (Comparative Example 4) which is an adhesive, in the weather resistance test The decrease in the mass of the covered soil could not be reduced sufficiently.

  In addition, even when the watering condensation method is used, as in the case of the kneading condensation method, when the clear coating agent (Examples 7 and 8), which is an acrylic resin, is included in the covered soil, the weight reduction of the covered soil is extremely reduced. It was found that it can be reduced.

(Weather resistance test 2)
A weather resistance test 2 was performed using the test pieces of the covered soil obtained in Examples 9 to 19 and Comparative Example 9. First, attach the test piece to the Atlas Ci35A Xenon-ometer weathering tester so that the 4.7 × 14.8 cm surface (the upper part of the wooden frame) of these test pieces can be irradiated and sprinkled with water. Light irradiation was performed for 200 hours under the condition of watering.

  And the mass of each test piece after completion | finish of a test was measured, and the decreasing amount of mass was computed. The obtained results are shown in FIG.

  As shown in FIG. 3, it was found that the amount of decrease in the mass of the coated soil can be further reduced by increasing the resin content and the water mixing ratio in the coated soil of the present invention.

  On the other hand, in the covered soil not including the present invention including PLASEMA L110 (Comparative Example 9), which is a biodegradable plastic, the amount of decrease in the mass of the covered soil in the weather resistance test could not be sufficiently reduced.

(change over time)
In a 60 L bucket, add 12 kg of water (mixed water ratio of 60%), 2.4 kg of clear coat agent and 36 kg of sodium citrate dihydrate, stirring with a hand mixer, 20 kg of hemihydrate gypsum, sand 30 kg was added little by little so as not to become a mass. After the hemihydrate gypsum and sand were sufficiently dispersed, the obtained kneaded material was poured onto the soil surface and adjusted with a gold trowel so as to have an even thickness and a smooth surface.

  Then, by leaving it to stand for 50 minutes, the kneaded material was hardened and a coated soil having a thickness of 30 mm was obtained.

  The obtained coated soil was regularly followed up for the progress of surface degradation and the maintenance of weed control effect. As a result, the data at the time when one year passed was in agreement with the results of the weather resistance test described above.

  From the above, according to the soil covering material of the present invention, it was confirmed that the dissolution rate of dihydrate gypsum in water can be delayed. Therefore, it is considered that the soil covered with the above-mentioned soil covering material can maintain the herbicidal effect for a long time. .

FIG. 1 is a cross-sectional view showing an embodiment of a roadside tree in which coated soil according to the present invention is constructed. FIG. 2 is a diagram showing the results of the weather resistance test 1 in this example. FIG. 3 is a diagram showing the results of the weather resistance test 2 in this example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Tree, 2 ... Covered soil, 2a ... Surface, 3 ... Soil, 3a ... Surface, 5 ... Concrete frame, 8 ... Hole.

Claims (5)

  (A) at least one selected from the group consisting of earth and sand, crushed materials and waste materials (excluding wood waste materials), (B) at least one selected from the group consisting of anhydrous gypsum and hemihydrate gypsum, and (C) A soil covering material containing at least one selected from the group consisting of vinyl acetate resins and acrylic resins.   The content of the component (A) in the soil covering material is 50 to 80% by mass, the content of the component (B) is 10 to 50% by mass, and the content of the component (C) is 1. The soil covering material according to claim 1 which is -30 mass%.   The soil covering material according to claim 1 or 2, wherein the soil covering material further contains (D) a setting retarder. The soil covering material according to claim 3 , wherein the setting retarder is at least one selected from the group consisting of sodium citrate, citric acid, calcium acetate, calcium oxalate, and hydrates thereof. A kneading step of kneading the soil covering material according to any one of claims 1 to 4 and water to obtain a kneaded product,
A laying step of laying the kneaded material at a predetermined position on the soil surface;
A curing step for curing the kneaded product;
The manufacturing method of the covering soil characterized by comprising.

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