Waterproofing material and method for manufacturing the same

Abstract

This invention provides a waterproofing material and a method for manufacturing the same, which can effectively utilize dewatered crushed stone cake, a by-product of the crushed stone and crushed sand manufacturing process, as a substitute for metal shavings, while also exhibiting high waterproofing performance. [Solution] The water content of the dewatered crushed stone cake 2, which is produced in the crushed stone and crushed sand manufacturing process, is adjusted to 20% to form the waterproofing material 1 by mixing it with crushed stone powder 3 with a particle size of 0.5 mm or less. The dewatered crushed stone cake 2 is made from dewatered cake produced from sludge generated in the manufacturing process of crushed stone and crushed sand, which are made from rocks that do not contain harmful organic matter or heavy metals. When mixing in the crushed stone powder 3, the dewatered crushed stone cake 2 is crushed before mixing in the crushed stone powder 3, and the crushed dewatered crushed stone cake 2 is mixed with the crushed stone powder 3 to ensure that the crushed stone powder 3 is uniformly mixed in.

Description

【Technical Field】 【0001】 This invention relates to a water barrier material and a method for manufacturing the same, and more particularly, to a manufacturing technique of a water barrier material using crushed stone dewatering cake generated in the manufacturing process of crushed stone and crushed sand. 【Background Art】 【0002】 Conventionally, natural sand (mountain sand, river sand, sea sand, etc.) has been used as an aggregate for concrete. However, in recent years, the extraction volume of these sands has been decreasing, and there is a tendency for natural sand to be in short supply. Therefore, recently, the use of crushed stone and crushed sand as an aggregate for concrete instead of natural sand has been increasing, and accordingly, the demand for crushed stone and crushed sand has been increasing. 【0003】 FIG. 4 shows an outline of the manufacturing process of crushed stone and crushed sand. As shown in the figure, the manufacturing of crushed stone and crushed sand involves collecting raw stones as raw materials from a raw stone mountain, introducing the collected raw stones into a manufacturing plant for crushed stone and crushed sand, and artificially crushing the raw stones in the manufacturing plant to produce crushed stone and crushed sand for concrete aggregate adjusted to a desired particle size (for example, see Patent Document 1). 【Prior Art Documents】 【Patent Documents】 【0004】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2012-55804 【Summary of the Invention】 【Problems to be Solved by the Invention】[[ID=-35]] 【0005】 In the crushed stone and crushed sand manufactured in this way, impurities such as soil particles and dust are removed in the water washing process during the manufacturing process. The removed impurities are taken out as sludge containing a large amount of moisture. Since the taken-out sludge is not suitable for treatment such as disposal as it is, a flocculant is added and dehydrated with a dehydrator such as a filter press, and discharged to the outside as a dewatering cake (crushed stone dewatering cake). 【0006】 As shown in Figure 4, the majority of dewatered crushed stone cake discharged into the environment is disposed of in landfills. However, this type of landfill disposal presents many problems, including difficulty in finding disposal sites due to a decrease in available locations, and increased disposal costs due to rising transportation costs to disposal sites. Improvements have been desired. In particular, in recent years, there has been a growing momentum toward realizing a sustainable society, exemplified by the SDGs (Sustainable Development Goals), and there has been a strong desire for the effective utilization of dewatered crushed stone cake as a resource. 【0007】 On the other hand, in Japan, there are many irrigation reservoirs in areas with low rainfall and no nearby water sources such as rivers. Many of these reservoirs have been in place for a considerable time and are deteriorating, making their repair and renovation desirable. However, natural clay soil (soil containing a large amount of clay and used as a waterproofing material) used for repairing and renovating reservoir embankments is difficult to obtain due to its limited supply. For this reason, in recent years, waterproofing sheets have been used as a substitute for clay soil for the repair and renovation of reservoirs (waterproofing sheet method). However, waterproofing sheets contain materials that are not naturally derived, and their long-term safety (over several decades) is unknown. 【0008】 This invention has been made in view of the above problems, and its objective is to provide a waterproofing material and a method for manufacturing the same that can effectively utilize the dewatered crushed stone cake generated in the manufacturing process of crushed stone and crushed sand as a substitute for metal shavings, and that exhibits high waterproofing performance. [Means for solving the problem] 【0009】 To achieve the above objective, the waterproofing material according to the present invention is characterized in that crushed stone powder with a particle size of 0.5 mm or less is mixed with the dewatered crushed stone cake generated in the crushed stone and crushed sand manufacturing process. 【0010】 In this invention, dewatered crushed stone cake is used as a component of the waterproofing material. This allows the dewatered crushed stone cake to be effectively utilized as a waterproofing material. Since both the dewatered crushed stone cake and the crushed stone powder, which are components of the waterproofing material, are naturally derived materials produced in the manufacturing process of crushed stone and crushed sand, they do not contain substances that have an adverse effect on the environment (for example, organic matter or heavy metals). Therefore, the waterproofing material according to the present invention can be safely used as a substitute for metal mortar in the renovation and repair of reservoirs. 【0011】 Furthermore, in a preferred embodiment of the present invention, the moisture content of the dewatered crushed stone cake mixed with the crushed stone powder is adjusted to 20%. The reason for adjusting the moisture content of the dewatered crushed stone cake to 20% is that when the dewatered crushed stone cake is used as a waterproofing material, it is compacted as described later, but if the moisture content is too high (close to liquid and sludgy) or too low (close to powder and free-flowing), neither is suitable for compaction. The applicant conducted experiments with various moisture content levels and found that a moisture content of 20% was the most suitable moisture content (optimal moisture content) for use as a waterproofing material. 【0012】 Another preferred embodiment is characterized in that the crushed stone powder is mixed with the dewatered crushed stone cake at a weight ratio of 50%. 【0013】 The present invention relates to a method for manufacturing a water-impermeable material, characterized by comprising: a crushing step of crushing a dewatered crushed stone cake generated in the crushing stone and crushed sand manufacturing process; and a crushed stone powder mixing step of mixing crushed stone powder with a particle size of 0.5 mm or less with the dewatered crushed stone cake crushed in the crushing step. 【0014】 In this invention, when manufacturing the waterproofing material, the dewatered crushed stone cake generated in the crushed stone and crushed sand manufacturing process is crushed and then mixed with crushed stone powder, so that the crushed stone powder can be uniformly mixed into the dewatered crushed stone cake. As a result, uneven mixing of the crushed stone powder can be eliminated, and waterproofing material can be manufactured without variations in waterproofing performance due to uneven mixing. 【0015】 Furthermore, in a preferred embodiment thereof, the present invention is characterized in that the crushed stone powder is composed of crushed stone powder obtained by introducing the crushed stone powder recovered in the manufacturing process of the crushed stone and crushed sand into an air-flow drying and separation device to separate the powder with a particle size of 0.5 mm or less. 【0016】 In this invention, since the crushed stone powder mixed into the dewatered crushed stone cake is dried and particle size adjusted by an air-flow drying and separation device, it is possible to use crushed stone powder with uniform (stable) particle size and moisture content as the crushed stone powder mixed into the dewatered crushed stone cake. As a result, the process of adjusting the moisture content of the dewatered crushed stone cake to a desired moisture content can be easily carried out. 【0017】 Furthermore, in another preferred embodiment of the present invention, the crushed stone powder mixing step is characterized in that the crushed stone powder is mixed so that the water content of the dewatered crushed stone cake after mixing is 20%. 【0018】 In another preferred embodiment, the crushed stone powder mixing step is characterized by mixing the crushed stone powder with the dewatered crushed stone cake at a weight ratio of 50%. [Effects of the Invention] 【0019】 According to the present invention, since dewatered crushed stone cake is used as a constituent material of the waterproofing material, dewatered crushed stone cake, which was conventionally disposed of in landfills, can be effectively utilized as a waterproofing material. Therefore, the waterproofing material according to the present invention can be used effectively without wasting resources, and can contribute to the realization of a sustainable society. 【0020】 Furthermore, since the crushed stone dewatering cake and crushed stone powder that make up the waterproofing material are both naturally derived materials, the waterproofing material does not contain any substances that have adverse effects on the environment. Therefore, the waterproofing material according to the present invention can be used with confidence as a substitute for metal clay in the renovation and repair of reservoirs. [Brief explanation of the drawing] 【0021】 [Figure 1]It is a flowchart showing an example of the manufacturing process of the water barrier material according to the present invention, and schematically shows a crushed stone powder kneading process of mixing crushed stone powder into the crushed stone dewatered cake. [Figure 2] It is a flowchart showing an example of the manufacturing process of the crushed stone powder to be mixed into the crushed stone dewatered cake in the manufacturing process of the water barrier material. [Figure 3] It is a cross-sectional view showing an example of the embankment of a pond because the water barrier material is used. [Figure 4] It is a flowchart showing an example of the manufacturing process of crushed stone and crushed sand. 【Embodiments for Carrying Out the Invention】 【0022】 Hereinafter, embodiments of the present invention will be described in detail based on the drawings. In this specification and the drawings, components having substantially the same function are denoted by the same reference numerals, and redundant description is omitted. 【0023】 The water barrier material 1 according to the present invention is mainly a water barrier material used as a substitute for blade gold soil, and is composed mainly of a crushed stone dewatered cake 2 and crushed stone powder 3. 【0024】 The crushed stone dewatered cake 2 is a dewatered cake generated in the manufacturing process of crushed stone and crushed sand, and is generated from the sludge washed away in the water washing process of the workpiece in the manufacturing process of crushed stone and crushed sand, in which the original stone collected from the original stone mountain is artificially crushed into small pieces. Since the sludge washed away in the water washing process contains a large amount of moisture, it is not suitable for treatment such as disposal as it is. Therefore, a flocculant is added to the washed-away sludge to separate impurities such as soil particles and dust contained in the sludge from the moisture, and the separated impurities are dehydrated by applying them to a dehydrator such as a filter press, thereby generating a paste-like dewatered cake (crushed stone dewatered cake) with reduced moisture. In this embodiment, the crushed stone dewatered cake 2 thus generated is used as a raw material for the water barrier material 1. 【0025】 Here, we will describe in detail the dewatered crushed stone cake 2 used in this embodiment. The dewatered crushed stone cake 2 shown in this embodiment is a dewatered cake produced at a crushed stone and crushed sand manufacturing plant that uses the Hara area of ​​Takatsuki City, Osaka Prefecture as its raw material site. The dewatered crushed stone cake 2 produced at this manufacturing plant does not contain harmful organic matter or heavy metals. Furthermore, the average moisture content of the dewatered crushed stone cake 2 after dewatering is 27%. In addition, pH measurement by physical testing showed that the measured pH value was 8.2, which is within the drinking water quality standard value (pH value: 5.8 to 8.6). In other words, according to the pH measurement results, it was confirmed that there was almost no influence (influence on the pH value) from the coagulant used in the production process of the dewatered cake. Furthermore, in the ignition loss test, the amount of organic matter other than the crystal water originally contained in the minerals was trace. In other words, it was found that the dewatered crushed stone cake 2 has a low possibility of decay or corrosion. Furthermore, the permeability coefficient of the dewatered crushed stone cake 2 is 7.1 × 10⁻⁶. -8 The pH was found to be cm / sec, indicating very high water-impermeable properties. Thus, the dewatered crushed stone cake 2 used in this embodiment has a nearly neutral pH value, has little impact on the environment, is resistant to decay and corrosion even with long-term use, and has high water-impermeable properties, making it suitable as a substitute material for metal clay. 【0026】 The crushed stone powder 3 is a crushed stone powder produced in the crushed stone and crushed sand manufacturing process, similar to the crushed stone dewatering cake 2 described above, and the waterproofing material 1 according to the present invention is constructed by mixing the crushed stone powder 3 with the crushed stone dewatering cake 2 described above. 【0027】 In mixing the crushed stone powder 3 with the crushed stone dewatering cake 2, the applicant conducted detailed experiments to determine the particle size, water content, and mixing ratio of the crushed stone powder 3 to be used with the crushed stone dewatering cake 2. As a result, the applicant found that by using crushed stone powder with the following configuration, a waterproofing material 1 with high waterproofing performance and excellent handling properties can be obtained. 【0028】 In other words, it is desirable to use crushed stone powder 3 with a particle size of 0.5 mm or less as the crushed stone powder 3 to be mixed into the crushed stone dewatered cake 2. The reason why the particle size of the crushed stone powder 3 is set to 0.5 mm or less is that if the particle size of the crushed stone powder 3 is large, the crushed stone dewatered cake 2 will be difficult to hold together after the crushed stone powder 3 is mixed in. In this embodiment, crushed stone powder 3 with a particle size adjusted to 0.05 mm to 0.5 mm is used. 【0029】 Figure 2 shows an example of the manufacturing process for crushed stone powder 3. The manufacturing process for crushed stone powder 3 shown in Figure 2 involves adjusting the particle size of the raw crushed stone powder (specifically, raw crushed stone powder with a particle size of 0.5 mm or less) generated in the previous process (crushed stone and crushed sand manufacturing process) to within the range of 0.05 mm to 0.5 mm. In this embodiment, the crushed stone dewatering cake 2 manufacturing plant described above is used as the crushed stone and crushed sand manufacturing plant that carries out the previous process. That is, in this embodiment, the same raw material (rock) as that used for crushed stone dewatering cake 2 is used as the raw material for crushed stone powder 3. 【0030】 The raw crushed stone powder 100 produced in the previous crushed stone and crushed sand manufacturing process is then introduced into the airflow dryer 102 via a conveying means 101 such as a screw conveyor. The airflow dryer 102 is a drying device having an airflow pipe (not shown) into which high-temperature drying gas is blown. By introducing the raw crushed stone powder 100 to the base end of the airflow pipe, the introduced raw crushed stone powder 100 is transported downstream on the drying gas flow through the airflow pipe. The raw crushed stone powder 100 transported on the drying gas flow is dried as it moves through the airflow pipe and reaches the downstream end of the airflow pipe in a dried state. The raw crushed stone powder 100 that has reached the downstream end of the airflow pipe is introduced into a cyclone 103 that classifies the raw crushed stone powder 100. 【0031】 The cyclone (airflow drying and sorting device) 103 is a device that dries and classifies powder using a powerful swirling airflow. It is configured to separate and classify the raw crushed stone powder 100 sucked in from the airflow pipe of the airflow dryer 102 into powder (fine powder) that is carried by the airflow and collected by the dust collector 104 and powder that falls without being carried by the airflow. In this embodiment, the device is configured so that powder with a particle size of approximately 0.05 mm or less is collected via the dust collector 104, and the powder collected by the dust collector 104 is accumulated in a dedicated silo (powder raw material silo) which is not shown. 【0032】 On the other hand, powder particles with a particle size of 0.05 mm or larger fall without being carried by the airflow in the cyclone 103. The fallen powder is collected in a designated silo 105. The powder collected in the silo 105 in this way has its particle size adjusted to within the range of 0.05 to 0.5 mm. In this embodiment, the powder with the particle size adjusted in this way is used as crushed stone powder 3 to be mixed with the crushed stone dewatered cake 2. 【0033】 In the mixing of the crushed stone powder 3, the crushed stone powder 3 is mixed with the dewatered crushed stone cake 2 so that the moisture content of the dewatered crushed stone cake 2 after mixing with the crushed stone powder 3 is 20% (or a value close to 20%). In this embodiment, the crushed stone powder 3 is mixed with the dewatered crushed stone cake 2 at a weight ratio of 50%, thereby reducing the moisture content of the dewatered crushed stone cake 2 to 20%. The reason for adjusting the moisture content of the dewatered crushed stone cake 2 to 20% is that when the dewatered crushed stone cake 2 is used as a waterproofing material, it will be compacted as described later. If the moisture content is too high, it will become almost liquid and muddy, while if the moisture content is too low, it will become almost powdery and dry, and in either case, it will be unsuitable for compaction. Experiments conducted by the applicant showed that a moisture content of 20% was the most suitable state for use as a waterproofing material 1, so in this embodiment, the moisture content of the dewatered crushed stone cake 2 is adjusted to 20%. 【0034】 Next, the manufacturing process of the waterproofing material 1 will be explained in detail based on Figure 1. Figure 1 shows the manufacturing plant for the waterproofing material 1. As shown in the figure, the dewatered crushed stone cake 2 produced in the crushed stone and crushed sand manufacturing plant is fed into the crusher 10. The crusher 10 is a device that breaks down the dewatered crushed stone cake 2, which is in a state of aggregated soil particles and dust, into smaller pieces. The dewatered crushed stone cake 2 is broken down into small pieces by this crusher 10 (crushing process). 【0035】 The crushed stone dewatered cake 2, which has been crushed in the crushing process, is introduced into the crushed stone powder mixing process, in which crushed stone powder 3 is mixed with the crushed stone dewatered cake 2. 【0036】 In this embodiment, the crushed stone powder mixing process is carried out by a resource recycling device (for example, "Kekuru II" manufactured by Kiko Co., Ltd.) 11 that cuts out the dewatered crushed stone cake 2, crushes it, and mixes it. As shown in Figure 1, the resource recycling device 11 mainly consists of a rotary hopper 12 and a crushing and mixing mechanism 13. 【0037】 The rotary hopper 12 constitutes a cutting mechanism that cuts the crushed stone dewatered cake 2 contained in the hopper into predetermined sizes and introduces them into the crushing and mixing mechanism 13. It comprises a bottomed cylindrical hopper body 14, a cutter 15 attached to an opening 16 formed at the bottom of the hopper body 14, and a rotational drive mechanism (not shown) that rotates the hopper body 14 around a rotation axis 17. As the hopper body 14 rotates, the crushed stone dewatered cake 2 contained in the hopper body 14 is cut out by the cutter 15 and introduced into the crushing and mixing mechanism 13 through the opening 16. 【0038】 The crushing and mixing mechanism 13 is a mechanism for mixing crushed stone powder 3 with the crushed stone dewatered cake 2 cut out by the rotary hopper 12, and mainly comprises a main body case 20, an in-machine crusher 21, a mixing and crushing machine 22, and an introduction passage 23 for the crushed stone powder 3. 【0039】 The main case 20 is a case that houses the in-machine crusher 21 and the mixing / crushing machine 22, and is located below the rotary hopper 12 as shown in the figure. The in-machine crusher 21 is a device that crushes the dewatered crushed stone cake 2 cut out from the opening 16 of the rotary hopper 12, and is located facing the opening 16 of the rotary hopper 12, and crushes the dewatered crushed stone cake 2 discharged from the opening 16 into small pieces ranging in size from a few millimeters to tens of millimeters. The introduction passage 23 for crushed stone powder 3 is a passage for introducing crushed stone powder 3 into the main case 20, and one end is connected to a supply source of crushed stone powder 3 (for example, a silo 105 for accumulating crushed stone powder 3) which is not shown, and the other end is arranged to face the crushing outlet side of the in-machine crusher 21, and the crushed stone powder 3 introduced into the main case 20 via the introduction passage 23 is configured to merge with the dewatered crushed stone cake 2 crushed by the in-machine crusher 21. 【0040】 The crushed stone dewatered cake 2, which has been combined with the crushed stone powder 3, is introduced into a kneading and crushing machine 22 located inside the main body case 20. The kneading and crushing machine 22 is a device that crushes and kneads the combined mixture of crushed stone powder 3 and crushed stone dewatered cake 2 introduced into the machine, and in this embodiment, there are multiple (three in the illustrated example) kneading and crushing machines 22, 22, ... The combined mixture of crushed stone powder 3 and crushed stone dewatered cake 2 passes through these multiple kneading and crushing machines 22, 22, ..., so that the crushed stone dewatered cake 2 and crushed stone powder 3 are evenly and substantially uniformly mixed and kneaded. In this embodiment, the mixing ratio of crushed stone dewatered cake 2 and crushed stone powder 3 is adjusted in this crushing and kneading mechanism 13. In other words, by increasing the amount of dry crushed stone powder 3 introduced, the moisture content of the dewatered crushed stone cake 2 can be lowered. Therefore, the amount of crushed stone powder 3 introduced is adjusted to adjust the moisture content of the dewatered crushed stone cake 2 to 20%. 【0041】 In this way, the mixture (kneaded material) of the dewatered crushed stone cake 2 and crushed stone powder 3, whose moisture content has been adjusted, is discharged to the outside as a waterproofing material 1 from the discharge port (not shown) of the main case 20. The discharged waterproofing material 1 is transported to a collection point for the waterproofing material 1 via a conveying device 30 such as a belt conveyor. 【0042】 However, the waterproofing material 1 manufactured in this manner is suitable for use as a substitute for burial clay used in the renovation and repair work of reservoirs. Figure 2 shows an example of the structure of a reservoir 40 using the waterproofing material 1. As is well known, a reservoir 40 is a civil engineering structure constructed to store water using an artificial embankment 41. Conventionally, this embankment 41 has a waterproofing zone 42 made up of a soil layer (burial clay layer) formed by compacting soil with a high viscosity that is impermeable to water (burial clay) within the embankment that makes up the embankment 41. The waterproofing material 1 according to the present invention can be used as a substitute for all or part of the burial clay when constructing this waterproofing zone 42. Therefore, according to the waterproofing material 1 according to the present invention, the crushed stone dewatered cake 2 that was previously disposed of in landfills can be effectively utilized as a substitute for burial clay, and it is possible to contribute to the realization of a sustainable society through the effective use of resources. 【0043】 Furthermore, since the waterproofing material 1 according to the present invention is composed of naturally derived crushed stone powder 3 with a particle size of 0.5 mm or less mixed with naturally derived crushed stone dewatered cake 2, the waterproofing material 1 does not contain any substances that have adverse effects on the environment. Therefore, even when the waterproofing material 1 according to the present invention is used, for example, in a reservoir for agricultural irrigation, there is no adverse effect on the environment, and the water in the reservoir can be used with peace of mind. 【0044】 The embodiments described above are merely preferred embodiments of the present invention, and the present invention is not limited to these, with various design modifications possible within its scope. 【0045】 For example, in the embodiment described above, the case in which rocks originating from the Hara area of ​​Takatsuki City, Osaka Prefecture were used as raw materials (raw materials) for the crushed stone dewatering cake 2 and crushed stone powder 3 was shown. However, as long as the raw materials do not contain harmful organic substances or heavy metals, rocks originating from other regions can also be used as raw materials for the crushed stone dewatering cake 2 and crushed stone powder 3. 【0046】 Furthermore, in the above-described embodiment, the crushed stone powder 3 mixed into the crushed stone dewatering cake 2 was shown to have a particle size adjusted to within the range of 0.05 mm to 0.5 mm. However, the particle size of the crushed stone powder 3 mixed into the crushed stone dewatering cake 2 can be changed as appropriate as long as it is 0.5 mm or less. In this regard, in the above-described embodiment, the raw crushed stone powder 100 was shown to be dried in an air-flow dryer 102 and then classified in a cyclone 103 in order to produce the crushed stone powder 3. However, these can also be carried out in a single device equipped with drying and classification functions. 【0047】 Furthermore, in the embodiment described above, the case in which crushed stone powder 3 was mixed with the dewatered crushed stone cake 2 at a weight ratio of 50% was shown when manufacturing the waterproofing material 1. However, the weight ratio of crushed stone powder 3 can be changed as appropriate, as long as the moisture content of the waterproofing material 1 mixed with crushed stone powder 3 becomes 20%. 【0048】 Furthermore, in the above-described embodiment, a resource recycling device 11 was shown that performs the cutting, crushing, and mixing of the dewatered crushed stone cake 2 in a single unit as the device for performing the crushed stone powder mixing process. However, in the crushed stone powder mixing process, it is sufficient to mix the crushed stone powder 3 with the dewatered crushed stone cake 2 that was crushed in the crushing process, and other types of devices can be used, such as a device that only performs mixing. 【0049】 Furthermore, although the above-described embodiment showed the case in which the waterproofing material 1 according to the present invention was used as the metal soil constituting the waterproofing zone 42 of the reservoir, the waterproofing material 1 according to the present invention can of course be used for purposes other than the embankment of a reservoir, as long as it is used as soil (soil layer) for the purpose of stopping water. [Explanation of symbols] 【0050】 1. Waterproofing material 2. Dewatered crushed stone cake 3. Crushed stone powder 10. Crusher 11 Resource Recycling Equipment 12 Rotating Hopper 13. Crushing and mixing mechanism 14 Hopper body 15 cutters 21. In-flight crusher 22 Mixing and crushing machines 23. Introduction road for crushed stone powder 30 Conveying device 40 reservoirs 41 Embankment body 42 Waterproof Zone 100 Raw material crushed stone powder 101 Screw Conveyor 102 Airflow dryer 103 Cyclone (Airflow drying and separation device) 104 Dust collector 105 Crushed stone silo

Claims

[Claim 1] Crushed stone powder with a particle size of 0.5 mm or less is mixed into the dewatered crushed stone cake generated in the crushed stone and crushed sand manufacturing process. A waterproofing material characterized by the following features. [Claim 2] The crushed stone dewatered cake, in which the crushed stone powder is mixed, has its moisture content adjusted to 20%. The waterproofing material according to feature 1. [Claim 3] The crushed stone powder is mixed with the dewatered crushed stone cake at a weight ratio of 50%. The waterproofing material according to claim 1 or 2. [Claim 4] The crushing process involves crushing the dewatered crushed stone cake generated in the manufacturing process of crushed stone and crushed sand, The process includes a crushed stone powder mixing step in which crushed stone powder with a particle size of 0.5 mm or less is mixed with the crushed stone dewatered cake that has been crushed in the crushing step. A method for manufacturing a water-impermeable material characterized by the following: [Claim 5] The aforementioned crushed stone powder is composed of crushed stone powder obtained by introducing the crushed stone powder recovered in the crushed stone and crushed sand manufacturing process into an air-flow drying and separation device to separate the powder with a particle size of 0.5 mm or less. A method for manufacturing a water-impermeable material according to feature 4. [Claim 6] The crushed stone powder mixing step involves mixing the crushed stone powder so that the moisture content of the dewatered crushed stone cake after mixing is 20%. A method for manufacturing a water-impermeable material according to claim 4 or 5. [Claim 7] The crushed stone powder mixing step involves mixing the crushed stone powder with the dewatered crushed stone cake at a weight ratio of 50%. A method for manufacturing a water-impermeable material according to claim 4 or 5.

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