Weed-proofing construction method and weed-proofing pavement structure

Abstract

To provide a weed-proofing method and a weed-proofing pavement structure which are inexpensive in material cost, excellent in workability, capable of maintaining good appearance and environment after construction, and capable of improving water permeability function and water retention function.SOLUTION: On existing soil 1, a mixture 2A obtained by mixing 100 parts by mass of waste melting furnace granulated slag with 5 to 15 parts by mass of cement or a mixture 2B obtained by further mixing 3 to 10 parts by mass of liquid resin or a mixture 2C obtained by mixing 100 parts by mass of blast furnace granulated slag with 5 to 15 parts by mass of cement and 5 to 20 parts by mass of liquid resin is laid to a construction thickness of 8 to 15 cm, and thereafter, water 3 is sprayed on the surface layer to suppress the growth of weeds from below.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a weed control method and a weed control pavement structure for suppressing the growth of weeds. [Background technology]

[0002] Weeds grow in planted areas of parks, unpaved walkways, and planted areas such as road medians, and if left unattended, they will grow and spread.

[0003] Conventional weed control methods for suppressing the growth of weeds include covering the area around the plantings with weed control sheets and laying concrete, but these methods have the potential to impede the permeability of rainwater and other sources around the plantings.

[0004] Another method is to suppress weed growth by laying natural sand or soil on top of the existing soil below to block sunlight. However, natural sand and soil can contain weed seeds, which can cause weeds to grow in the laid natural sand or soil. Weed seeds can be removed by heat treating the natural sand or soil at high temperatures, but this requires high material costs.

[0005] Therefore, the present inventors have disclosed in Patent Document 1 a weed control method in which granulated waste melting furnace slag is laid down to a predetermined thickness to suppress the growth of weeds from below. The granulated waste melting furnace slag referred to in Patent Document 1 is produced by melting municipal and industrial waste in a waste melting furnace at high temperatures of 1200°C or higher, rapidly crushing the resulting molten material with water, removing metallic iron by magnetic separation, and reducing the metallic iron content to 1% by mass or less. The weed control method of Patent Document 1 uses such granulated waste melting furnace slag, which has the advantages of low material costs, excellent workability, and maintaining a good appearance and environment after construction.

[0006] Meanwhile, Patent Document 2 discloses a weed control method using blast furnace slag, specifically describing the heating and drying of the blast furnace slag to prevent the slag from solidifying. However, even if heated and dried blast furnace slag is used, if moisture adheres to the blast furnace slag due to watering during construction or rainfall after construction, the latent hydraulic properties of the blast furnace slag are restored, leading to solidification after construction or rainfall. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 5582599 [Patent Document 2] Patent No. 4086113 Summary of the Invention [Problem to be solved by the invention]

[0008] The present inventors have recognized the need to further improve the water permeability and water retention properties of the weed control method of Patent Document 1. However, even if blast furnace slag that has been heat-dried is simply used as in Patent Document 2, it is difficult to improve the water permeability and water retention properties because, as mentioned above, solidification occurs after construction and rainfall.

[0009] To provide a weed control method and a weed control pavement structure which are inexpensive in material cost, have excellent workability, can maintain good aesthetics and the environment after construction, and can improve water permeability and water retention. [Means for solving the problem]

[0010] In order to solve the above problems, the inventors of the present invention have conducted tests and studies focusing on the type and properties of the aggregate used, the amount of cement mixed with the aggregate, the thickness of construction, etc., and have obtained the following findings. (1) When using granulated slag from a waste melting furnace as aggregate, mixing 5 to 15 parts by mass of cement with 100 parts by mass of granulated slag from a waste melting furnace and laying the mixture to a construction thickness of 8 to 15 cm will improve the permeability and water retention properties. (2) When using granulated slag from a waste melting furnace as aggregate, the permeability and water retention properties can be further improved by mixing 5 to 15 parts by mass of cement and 3 to 10 parts by mass of liquid resin with 100 parts by mass of granulated slag from a waste melting furnace, and laying the mixture to a construction thickness of 8 to 15 cm. (3) When using granulated blast furnace slag as aggregate, by mixing 100 parts by mass of granulated blast furnace slag with 5 to 15 parts by mass of cement and 5 to 20 parts by mass of liquid resin and laying it to a thickness of 8 to 15 cm, the solidification of the granulated blast furnace slag after construction and rainfall is suppressed, and the permeability and water retention functions are improved. (4) For waste melting furnace granulated slag and blast furnace granulated slag, the design CBR value is 20% or more, and the permeability coefficient is 10 -4 By using a quality of m / s or higher, the permeability and water retention functions will be further improved.

[0011] The present invention has been conceived based on the above findings, and the gist of the present invention is as follows. 1. This is a weed control method in which general waste or industrial waste is melted in a waste melting furnace at a high temperature of 1200°C or higher, the resulting molten material is pulverized with water, and the metallic iron content is reduced to 1% by mass or less through magnetic separation.Furthermore, the granulated slag obtained from the waste melting furnace is mixed with 100 parts by mass of 5 to 15 parts by mass of cement and then laid to a thickness of 8 to 15 cm.After that, water is sprayed on the surface to suppress the growth of weeds from below. 2. A weed control method in which general waste or industrial waste is melted in a waste melting furnace at a high temperature of 1200°C or higher, the resulting molten material is pulverized with water, and the metallic iron content is reduced to 1% by mass or less by magnetic separation.Furthermore, the granulated slag obtained by the waste melting furnace is mixed with 100 parts by mass of 5 to 15 parts by mass of cement and 3 to 10 parts by mass of liquid resin, and then laid to a thickness of 8 to 15 cm.After that, water is sprayed on the surface to suppress the growth of weeds from below. 3. Design CBR value is 20% or more, and the coefficient of permeability is 10 -4 3. A weed control method according to 1 or 2, which uses granulated slag from a waste melting furnace having a quality of at least m / s. 4. A weed control method in which a mixture of 100 parts by mass of granulated blast furnace slag, 5 to 15 parts by mass of cement, and 5 to 20 parts by mass of liquid resin is laid to a thickness of 8 to 15 cm, and then water is sprayed on the surface to suppress the growth of weeds from below. 5. Design CBR value is 20% or more, and the coefficient of permeability is 10 -4 4. A weed control method according to 4, which uses granulated blast furnace slag having a quality of at least m / s. 6. A weed-proof pavement structure consisting of a mixture of 100 parts by mass of waste melting furnace granulated slag, which is obtained by melting general waste or industrial waste at high temperatures of 1200°C or higher in a waste melting furnace and pulverizing the resulting molten material with water, and which has a metallic iron content of 1% by mass or less and a particle size of 5 mm or less, mixed with 5 to 15 parts by mass of cement, and laid to a thickness of 8 to 15 cm. 7. A weed-proof pavement structure consisting of a mixture of 100 parts by mass of waste melting furnace granulated slag, which is obtained by melting general waste or industrial waste at high temperatures of 1200°C or higher in a waste melting furnace and pulverizing the resulting molten material with water, with a metallic iron content of 1% by mass or less and a particle size of 5 mm or less, mixed with 5 to 15 parts by mass of cement and 3 to 10 parts by mass of liquid resin, and laid to a thickness of 8 to 15 cm. 8. A weed-proof pavement structure in which a mixture of 100 parts by mass of granulated blast furnace slag, 5 to 15 parts by mass of cement, and 5 to 20 parts by mass of liquid resin is laid to a thickness of 8 to 15 cm. [Effects of the Invention]

[0012] According to the present invention, the material cost is low, the workability is excellent, the aesthetic appearance and environment after the work can be maintained in a good condition, and the water permeability and water retention function can be improved. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is an explanatory diagram showing a weed prevention method according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] The embodiments of the present invention are roughly divided into an embodiment in which granulated slag from a waste melting furnace is used as the aggregate (hereinafter referred to as the "first embodiment") and an embodiment in which granulated blast furnace slag is used as the aggregate (hereinafter referred to as the "second embodiment"). First, the first embodiment will be described.

[0015] In the first embodiment, granulated slag from a waste melting furnace is used as the aggregate. The term "granulated slag from a waste melting furnace" as used herein refers to a material obtained by melting municipal or industrial waste in a waste melting furnace at temperatures above 1,200°C, crushing the resulting molten material with water (rapid crushing, rapid cooling crushing; the slag discharged from the waste melting furnace is poured into water to rapidly cool, harden, and simultaneously crush into granules), reducing the metallic iron content to 1% by mass or less by magnetic separation, and then subjecting the slag to a particle size adjustment process. The term "particle size adjustment" as used herein collectively refers to sieving and particle size adjustment, which are performed after magnetic separation (either by crushing or grinding). The particle size of the granulated slag from a waste melting furnace obtained by this particle size adjustment process is 5 mm or less. The term "particle size" refers to the sieve mesh size specified by the nominal mesh size of the sieve as specified in JIS Z 8801-1, and a particle size of 5 mm or less means that the particle passes through a sieve with a mesh size of 5 mm. In this way, in the first form, granulated slag from a waste melting furnace is used, and as in the case of Patent Document 1 mentioned above, a weed control method and weed control pavement structure are obtained that are inexpensive in material cost, easy to install, and can maintain the aesthetic appearance and environment well after installation.

[0016] In the first embodiment, as shown in Figure 1, a mixture 2A made by mixing 100 parts by mass of granulated slag from a waste melting furnace with 5 to 15 parts by mass of cement is laid on the existing soil 1 in the lower layer to a thickness of 8 to 15 cm, and then water 3 is sprayed on the surface to suppress the growth of weeds from below. In the present invention, the water 3 is preferably sprayed in the form of a mist. In this way, in the first embodiment, by specifying the amount of cement mixed and the application thickness of the mixture, it is possible to improve the water permeability and water retention properties while maintaining the weed prevention function. That is, if the amount of cement mixed is less than 5 parts by mass, it becomes difficult to mix uniformly with the granulated waste melting furnace slag, and if it exceeds 15 parts by mass, the water permeability and water retention properties deteriorate. Regarding the application thickness of the mixture, the lower limit may be approximately 3 to 5 cm from the viewpoint of ensuring the weed prevention function, but in consideration of variations in the surface area of ​​the application site and thickness variations during application, the present invention sets the lower limit at 8 cm. On the other hand, there is no particular limit on the application thickness from the viewpoint of ensuring the weed prevention function, water permeability, and water retention properties, but in consideration of economic efficiency, the present invention sets the upper limit at 15 cm.

[0017] In one embodiment of the first embodiment described above, Mixture 2A was used, which was prepared by mixing 5 to 15 parts by mass of cement with 100 parts by mass of granulated waste melting furnace slag. However, in another embodiment of the first embodiment, Mixture 2B is used instead of Mixture 2A, which is prepared by mixing 5 to 15 parts by mass of cement and 3 to 10 parts by mass of liquid resin with 100 parts by mass of granulated waste melting furnace slag. That is, Mixture 2B is prepared by further mixing 3 to 10 parts by mass of liquid resin with Mixture 2A. By using Mixture 2B, which is further mixed with 3 to 10 parts by mass of liquid resin, it is possible to further improve the water permeability and water retention properties. That is, by using Mixture 2B, which is mixed with an appropriate amount of liquid resin, the porosity of the solidified material of Mixture 2B, which solidified by water spraying during construction, is improved by rainfall or the like after construction, thereby improving the water permeability and water retention properties of the solidified material. Specifically, after construction, rainfall, etc. causes some of the liquid resin in the solidified material to dissolve in rainwater, etc., and gradually flow out of the solidified material along with the rainwater, creating voids where the voids were. That is, after construction, rainwater, etc., penetrates the solidified material, passes through the solidified material, and enters the existing soil below. The liquid resin dissolves in the infiltrating rainwater, etc., and moves from the solidified material to the existing soil below along with the rainwater. As a result, voids form in the liquid resin that was in the solidified material, improving the porosity. This improves the permeability of the solidified material. Furthermore, because some of the rainwater, etc., is retained in the voids within the solidified material, the water retention of the solidified material is also improved.

[0018] To achieve these effects, the amount of liquid resin to be mixed is set to 3 to 10 parts by mass. If the amount of liquid resin is less than 3 parts by mass, the effect of improving the water permeability and water retention of the solidified product cannot be obtained. On the other hand, if the amount of liquid resin to be mixed exceeds 10 parts by mass, the water permeability and water retention may be deteriorated.

[0019] Using mixture 2B containing 3 to 10 parts by mass of liquid resin contributes to improving on-site workability. That is, if the construction area has a slope, it is preferable to use mixture 2B containing 3 to 10 parts by mass of liquid resin to improve on-site workability. However, if the construction area is only horizontal, it is not necessary to mix in liquid resin in order to improve on-site workability.

[0020] In the present invention, for example, "Sunrose (registered trademark)" (sodium carboxymethylcellulose) manufactured by Nippon Paper Chemicals Co., Ltd. can be used as the powder for liquid resin. Specifically, for example, a liquid resin mixed in a mass ratio of powder for liquid resin:water = 100:10 can be used.

[0021] As described above, in the first embodiment of the present invention, granulated slag from a waste melting furnace is used. The quality of the slag is such that the design CBR value is 20% or more and the permeability coefficient is 10 -4 It is preferable to use one with a quality of m / s or higher. Of these, the design CBR value is commonly used as an index to determine whether or not a pavement material can be used as a subgrade material to support it, and the higher the design CBR value, the higher the support rate.The test method for the design CBR value is specified in JIS A 1211 (CBR test method), and a penetration test is carried out using a CBR tester consisting of a loading device, load meter, penetration piston, and penetration amount measuring device, and the CBR value (design CBR value) is calculated by reading the load at penetration amounts of 2.5 mm and 5.0 mm while penetrating a 5 cm diameter piston at 1 mm / min. On the other hand, the coefficient of permeability is an index that indicates how easily water flows through soil; a high value means that water passes easily, and a low value means that water does not pass easily.The test method for permeability is specified in JIS A 1218 (method of soil permeability test), and the test specimen is placed in a cylinder, immersed in water, vacuum degassed to make it saturated, and the constant water level method (measurement of the amount of water passing through the soil sample with a constant water level difference) is used to determine the permeability.

[0022] The granulated waste melting furnace slag used in the first embodiment of the present invention is generated in a waste melting furnace, and the preferred type of waste melting furnace is a coke-bed waste melting furnace. A coke-bed waste melting furnace is a waste melting furnace that adds coke and limestone as secondary materials when general waste or industrial waste (hereinafter collectively referred to as "waste") is charged, and the coke and limestone added as secondary materials provide the following effects: That is, by adding coke as a secondary material, the following effects can be obtained. (1) The atmospheric temperature in the lower part of the furnace reaches a high temperature of 1700-1800°C, and the waste melts completely at this high temperature, resulting in the ash in the waste melting completely (the unmelted portion disappears). (2) The atmosphere inside the furnace becomes a high-temperature reducing atmosphere (a high-temperature atmosphere without oxygen), which causes harmful substances such as heavy metals in the waste to migrate into the gas system, thereby keeping the content of harmful substances in the molten material low. As a result, the safety is comparable to that of natural sand. In addition, adding limestone as a secondary material has the following effects: (3) By adjusting the proportion of limestone added depending on the type of waste, the concentrations of the main components of the molten material (silicic acid / SiO2, lime / CaO) can be stabilized throughout the year. (4) The stabilization of the concentration of the main components in the molten material and the high-temperature melting process facilitate the separation of the slag and metallic iron during rapid pulverization with water, improving the separation in the subsequent magnetic separation process. As a result, the metallic iron content in the resulting granulated slag from the waste melting furnace is significantly reduced. (5) The concentration of the main components in the molten material is stable throughout the year, and the quality of the resulting granulated slag from the waste melting furnace (design CBR value, permeability coefficient, particle size distribution) is also stable throughout the year. In addition, the stable particle size distribution improves the compaction performance.

[0023] Next, we will explain the second embodiment. As mentioned above, the second embodiment uses granulated blast furnace slag as aggregate. In this embodiment, 100 parts by mass of granulated blast furnace slag is mixed with 5 to 15 parts by mass of cement and 5 to 20 parts by mass of liquid resin (see Figure 1). Mixture 2C is laid to a thickness of 8 to 15 cm, and water is then sprayed onto the surface to suppress weed growth from below. Granulated blast furnace slag is a type of blast furnace slag. As mentioned above, if water is applied to the granulated blast furnace slag during construction or after construction, the latent hydraulic properties of the granulated blast furnace slag are restored, leading to solidification after construction and rainfall. In contrast, the second embodiment uses 5 to 20 parts by mass of liquid resin, which prevents the restoration of latent hydraulic properties and, similar to the first embodiment, improves permeability and water retention. In the second embodiment, a weed control method and a weed control pavement structure can be obtained that are inexpensive in material cost, have excellent workability, and can maintain a good appearance and environment after construction. Note that, while the amount of liquid resin mixed in the first embodiment is 3 to 10 parts by mass, in the second embodiment, the amount of liquid resin mixed in is 5 to 20 parts by mass, taking into account the effect of suppressing the recovery of the latent hydraulic properties of the granulated blast furnace slag.

[0024] The quality of the granulated blast furnace slag used in the second method is the same as that of the granulated waste melting furnace slag used in the first method, with a design CBR value of 20% or more and a permeability coefficient of 10 -4 It is preferable to use one with a quality of m / s or higher. [Explanation of symbols]

[0025] 1 Existing soil 2A,2B,2C mixture 3 water

Claims

1. This is a weed control method in which municipal or industrial waste is melted in a waste melting furnace at a high temperature of 1200°C or higher, the resulting molten material is pulverized with water, and the metallic iron content is reduced to 1% by mass or less by magnetic separation. The resulting granulated waste melting furnace slag is then subjected to a particle size adjustment process, and 100 parts by mass of the resulting granulated waste melting furnace slag is mixed with 5 to 15 parts by mass of cement. This mixture is then laid to a thickness of 8 to 15 cm, and water is then sprayed on the surface to suppress the growth of weeds from below.

2. This is a weed control method in which municipal or industrial waste is melted in a waste melting furnace at a high temperature of 1200°C or higher, the resulting molten material is pulverized with water, and the resulting molten material is magnetically separated to reduce the metallic iron content to 1% by mass or less. The resulting granulated waste melting furnace slag is then subjected to a particle size adjustment process, and 100 parts by mass of the resulting granulated waste melting furnace slag is mixed with 5 to 15 parts by mass of cement and 3 to 10 parts by mass of liquid resin. The mixture is then laid to a thickness of 8 to 15 cm, and water is then sprayed on the surface to suppress the growth of weeds from below.

3. Design CBR value is 20% or more, and the coefficient of permeability is 10 －４ 3. A weed control method according to claim 1 or 2, wherein granulated waste melting furnace slag having a quality of at least m / s is used.

4. A weed control method in which a mixture of 100 parts by mass of granulated blast furnace slag, 5 to 15 parts by mass of cement, and 5 to 20 parts by mass of liquid resin is laid to a thickness of 8 to 15 cm, and then water is sprayed on the surface to suppress the growth of weeds from below.

5. Design CBR value is 20% or more, and the coefficient of permeability is 10 －４ 5. The weed control method according to claim 4, wherein granulated blast furnace slag having a quality of at least m / s is used.

6. A weed-proof pavement structure comprising a mixture of 100 parts by mass of granulated waste melting furnace slag, which is obtained by melting municipal or industrial waste at high temperatures of 1200°C or higher in a waste melting furnace and pulverizing the resulting molten material with water, and which has a metallic iron content of 1% by mass or less and a particle size of 5 mm or less, and 5 to 15 parts by mass of cement, laid to a thickness of 8 to 15 cm.

7. A weed-proof pavement structure comprising a mixture of 100 parts by mass of granulated waste melting furnace slag, which is obtained by melting municipal or industrial waste at a high temperature of 1200°C or higher in a waste melting furnace and pulverizing the resulting molten material with water, and which has a metallic iron content of 1% by mass or less and a particle size of 5 mm or less, mixed with 5 to 15 parts by mass of cement and 3 to 10 parts by mass of liquid resin, and laid to a thickness of 8 to 15 cm.

8. A weed-proof pavement structure in which a mixture of 100 parts by mass of granulated blast furnace slag, 5 to 15 parts by mass of cement, and 5 to 20 parts by mass of liquid resin is laid to a thickness of 8 to 15 cm.

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