WO2012050076A1 - Recycled soil, planting soil, lawn top dressing, base course material, and soil for grounds - Google Patents

Abstract

Provided is a recycled soil obtained by combining: a molten slag grain material comprising molten slag of one or more types selected from general waste, industrial waste, and iron and steel slag, and adjusted in a manner such that the grain diameter thereof is 40mm or less; and a dehydrated cake grain material comprising a dehydrated cake obtained by dehydrating and drying one or more types of sludge selected from tap water sludge, sewage sludge, and paper sludge, and adjusted in a manner such that the grain diameter thereof is 40mm or less. It is preferable for the combination ratio of the molten slag and the dehydrated cake to be between 1:9 and 9:1, and even more preferable for the same to be between 3:7 and 7:3. It is possible to use this recycled soil as multipurpose soil, for example, as planting soil, base course material used as the base course in the paving of sidewalks and grounds, and soil for grounds.

Description

Recycled soil, planting soil, lawn filler, roadbed material, and ground soil

The present invention relates to recycled soil using recycled materials such as waste. Also used for planting soil used for cultivation of plants and vegetables, lawn filler used on the top of lawn for the purpose of enhancing the cushioning property of lawn, roadbed with sidewalk pavement or ground pavement structure It is related to soil for ground used in outdoor facilities such as playground materials used in sports fields such as schools, various stadiums, and parks.

In recent years, the recycling soil using the recycling material of the waste is attracting attention. As one of such things, Patent Document 1 describes soil for cultivation such as plants and vegetables using a dehydrated cake obtained by recycling waste.

Dehydrated cake is a solidified sludge generated from the water purification plant and sewage treatment plant of each municipality, meets certain safety standards, and exhibits neutral pH 7-8 in aqueous solution.
Since dehydrated cake is a recycling material that is continuously generated in a large amount in each local government, by using such a material, inexpensive planting soil can be continuously supplied. Moreover, since the amount of waste can be reduced by using recycled materials, the problem of shortage of waste disposal sites is also solved.

JP 2007-306844 A JP 2005-139880 A

Recycled soil is expected to be used for a wide range of purposes, such as soil for cultivation of plants and vegetables as described in Patent Document 1, as well as soil for ground and roadbed materials for paving. In many cases, the soil is required to have excellent water retention and water permeability.

The soil described in Patent Document 1 uses a dehydrated cake as a main raw material, and has the feature of being excellent in water retention, but has a problem of low water permeability.

The problem to be solved by the present invention is to provide a recycled soil that can be manufactured using a recyclable material that can be stably obtained at low cost, and has both excellent water retention and water permeability.

Recycled soil according to the present invention made to solve the above problems is
a) A molten slag granule composed of one or more types of molten slag selected from general waste, industrial waste, and steel slag, and having a particle size adjusted to 40 mm or less,
b) It is composed of dehydrated cake obtained by dehydrating and drying one or more selected from water sludge, sewage sludge, and paper sludge, and blended with dehydrated cake granules adjusted to a particle size of 40 mm or less. It is characterized by.

The recycled soil according to the present invention is blended with molten slag, which is a waste recycling material, like the dehydrated cake. Dehydrated cake has excellent water retention. In addition, the molten slag can be adjusted in particle size to an appropriate size, and as a result, an appropriate gap can be generated inside the soil to make the soil with water permeability. For this reason, it can be set as the soil which has water retention and water permeability by mix | blending a dewatering cake granule and a molten slag granule. The reason why the particle size is adjusted to 40 mm or less is to obtain a particle size commonly required for planting soil, roadbed material, ground soil and the like, which will be described later. When the purpose is limited, it is desirable to adjust the particle size to a size suitable for each purpose, as will be described later.
In order to combine the excellent water retention property of the dehydrated cake and the excellent water permeability obtained by adjusting the particle size of the molten slag, each of the molten slag and the dehydrated cake is blended at least 10% of the entire soil. It is desirable.

In the recycled soil according to the present invention, the molten slag granule and the dehydrated cake granule are desirably blended at a ratio of 3: 7 to 7: 3. More preferably, the molten slag granules and the dehydrated cake granules are blended in a ratio of 3: 7 to 5: 5. Recycled soil blended at such a ratio combines particularly excellent water retention and water permeability.

The recycled soil according to the present invention can be suitably used as planting soil for cultivating plants, vegetables and the like.
When the recycled soil according to the present invention is used as planting soil, the molten slag granule is adjusted to 20 mm or less, and the dehydrated cake granule is adjusted to a particle size of 20 mm or less.

The soil for planting needs to contain nutrients necessary for the growth of plants and the like in a well-balanced manner, unlike soil for roads and playgrounds. For this purpose, large pores are formed between the aggregates inside the soil, and small pores are formed inside the aggregates to activate the activities of soil microorganisms and soil small organisms, producing a lot of nutrients necessary for the growth of plants, etc. It is necessary to prepare the environment so that The soil having such a aggregate structure is excellent in terms of water retention and water permeability, and is suitable for growing plants and the like.

Since the soil for planting according to the present invention is blended with molten slag granules adjusted to a particle size of 20 mm or less and dehydrated cake granules adjusted to a particle size of 20 mm or less, these granules It has pores of a size suitable for growing plants and the like due to the gaps between them.

It is desirable that the molten slag granules and the dehydrated cake granules have a aggregate structure. In order to obtain a planting soil having a aggregate structure, it is desirable to add 0% to 20% of silt with respect to the total amount of the molten slag granules and the dehydrated cake granules. The silt component means a fine particle component such as sand powder or crushed stone powder.

Molten slag and dehydrated cake are manufactured in various places throughout the country, and the particle size distribution varies depending on the manufacturing location. If blended with 0% to 20% silt, it compensates for variations in the particle size distribution of molten slag granules and dehydrated cake granules, and has a pore size that is suitable for growing plants. Can be soil.

The recycled soil according to the present invention can also be suitably used as a roadbed material used for a roadbed with sidewalk pavement or ground pavement structure.

Conventionally, recycled crushed stone has been widely used for roadbed materials. Recycled crushed stone is a concrete by-product or asphalt concrete lumps that are reused after being crushed among construction by-products generated when building structures are demolished. However, when recycled crushed stone is used as a raw material, roadbed materials can be produced at low cost, but they have strong alkalinity (pH = 12.5), and have an adverse effect on drainage that exudes from roadside trees and soil.

Also, the development of roadbed materials aimed at suppressing the heat island phenomenon is underway. It has been studied to reduce the road surface temperature by heat of vaporization when the water retained in the roadbed material evaporates using the roadbed material having high water retention. As such a roadbed material, Patent Document 2 proposes a roadbed material made of granulated powder produced by crushing a dehydrated cake and adding a hydraulic binder.

In the roadbed material described in Patent Document 2, if blast furnace cement is used as the hydraulic binder, the water in the roadbed layer is brought close to neutrality, the road tree is not adversely affected, and the heat island phenomenon can be suppressed. The blast furnace cement is a cement obtained by mixing Portland cement with fine powder of blast furnace slag, which is a by-product generated from the blast furnace, which is a pig iron manufacturing process in an ironworks. However, when blast furnace cement is used, it is necessary to use Portland cement in addition to the fine powder of blast furnace slag, which is a recycled material.

The roadbed material according to the present invention preferably contains 0% to 20% crushed stone or recycled crushed stone with respect to the total amount of the molten slag particle material and the dehydrated cake particle material. Further, it is desirable that the roadbed material according to the present invention is blended with a silt content so that the fine particle content of the entire roadbed material is 3% to 18%.

The recycled soil according to the present invention can be suitably used as ground soil.
When the recycled soil according to the present invention is used as ground soil, the molten slag granules and the dehydrated cake granules are blended at a ratio of 4: 6 to 6: 4, and the molten slag granules are 9.5 mm or less. The dehydrated cake granule is adjusted to a particle size of 9.5 mm or less, and the silt content is blended so that the total fine particle content is 10% to 18%.

The recycled soil according to the present invention dehydrates one or more types of molten slag selected from general waste, industrial waste, and steel slag, and one or more types selected from water sludge, sewage sludge, and paper sludge. The dried dehydrated cake can be produced as a raw material. Therefore, the raw material can be obtained and manufactured stably at a low cost.
In addition, the recycled soil according to the present invention includes a dehydrated cake granule and a molten slag granule. Therefore, the recycled soil according to the present invention can be adjusted in particle size to an appropriate size, and as a result, an appropriate gap is generated inside the soil, thereby having water permeability.

Since the soil for planting according to the present invention is blended with a dehydrated cake granule having a particle size of 20 mm or less and a molten slag granule having a particle size of 20 mm or less, it has pores between these granules. Accordingly, the planting soil according to the present invention activates the activities of soil microorganisms and soil small organisms, and forms an environment in which many nutrients necessary for the growth of plants and the like are formed. Suitable for Moreover, it is excellent also in water retention and water permeability.

Since the roadbed material according to the present invention has excellent water retention and water permeability, the road surface temperature can be lowered by the heat of vaporization when the water retained inside the roadbed material evaporates, and the heat island phenomenon is suppressed. be able to.
Moreover, since the roadbed material according to the present invention does not have strong alkalinity, the roadside tree is not adversely affected.

The ground soil according to the present invention similarly has excellent water retention and water permeability. Also, the molten slag granules and the dehydrated cake granules are blended at a ratio of 4: 6 to 6: 4, the molten slag granules are adjusted to 9.5 mm or less, and the dehydrated cake granules are adjusted to a particle size of 9.5 mm or less. In addition, the silt content is blended so that the total fine particle content is 10% to 18%, so it has both elasticity suitable for ground soil and excellent compaction.

The figure which shows the manufacture procedure of the recycled soil which concerns on one embodiment of this invention. The figure which shows the test item and specification of the general characteristic of a soil, and a particle size characteristic. The figure which shows the test result of the general characteristic and particle size characteristic of the recycling soil which concern on the Example of this invention. The figure which shows the evaluation result regarding the water permeability characteristic of the recycle soil concerning the Example of this invention. The figure explaining the characteristic of the green foster LT used as the comparison soil in the planting experiment of gardenia. The figure which shows the experimental result which planted gardenia using the soil for planting which concerns on Example 1. FIG. The graph which shows the experimental result which planted gardenia using the soil for planting concerning Example 1. FIG. The figure explaining the test method of the soil characteristic regarding pH value, content of an active ingredient, etc. The figure which shows the test result regarding the pH value of the soil for planting which concerns on Example 1, content of an active ingredient, etc. The figure which shows the test result regarding the pH value, content of an active ingredient, etc. of the molten slag which is the raw material of the soil for planting which concerns on Example 1, dehydrated cake, and sand powder. The figure which shows the result of having investigated the characteristic regarding the three-phase distribution of the soil for planting which concerns on Example 1, a saturated hydraulic conductivity, an effective water | moisture content, and a particle size composition. The figure which shows the result of the aggregate structure confirmation test of the soil for planting which concerns on Example 1. FIG. The figure which shows the water retention test result of the soil for planting which concerns on Example 1. FIG. The graph which shows the change of the surface temperature of the natural turf grown using the soil for planting concerning Example 1. FIG. The graph which shows the change of the surface temperature of the artificial turf in the test which uses the recycle soil concerning the Example of this invention as an artificial turf filler. The figure which shows the additive and soil characteristic of the soil 1-11 used for the growth test of lettuce. The figure explaining the soil analysis result of soil x and soil 8. The figure which shows an example of the manufacture procedure of the roadbed material which concerns on Example 2. FIG. The figure which shows the water retention test result of a roadbed material and volcanic gravel concerning Example 2. FIG. The figure which shows the pavement structure in the comparative test of the heat island phenomenon suppression effect using the roadbed material and crushed stone which concern on Example 2. FIG. The figure which shows transition of the temperature of the surface layer surface in the comparative test of the heat island phenomenon suppression effect using the roadbed material and crushed stone which concern on Example 2. FIG. The figure which shows transition of the temperature of the position 100mm above the surface layer surface in the comparative test of the heat island phenomenon suppression effect using the roadbed material and crushed stone which concern on Example 2. FIG. The figure which shows transition of the temperature difference in the surface of the surface layer in the comparative test of the heat island phenomenon suppression effect using the roadbed material and crushed stone which concern on Example 2. FIG. The figure which shows transition of the temperature difference in a 100-mm upper position from the surface layer surface in the comparative test of the heat island phenomenon suppression effect using the roadbed material and crushed stone which concern on Example 2. FIG. The figure which shows the temperature difference in the specific time in the comparative test of the heat island phenomenon suppression effect using the roadbed material and crushed stone which concern on Example 2. FIG. The figure which shows the pavement structure in another comparative test of the heat island phenomenon suppression effect using the roadbed material and crushed stone which concern on Example 2. FIG. The figure which shows transition of the temperature of the surface of the surface layer in another comparative test of the heat island phenomenon suppression effect using the roadbed material and crushed stone which concern on Example 2. FIG. The figure which shows transition of the temperature of the position 100 mm above the surface layer surface in another comparative test of the heat island phenomenon suppression effect using the roadbed material and crushed stone concerning Example 2. FIG. The figure which shows transition of the temperature difference in the surface of the surface layer in another comparative test of the heat island phenomenon suppression effect using the roadbed material and crushed stone which concern on Example 2. FIG. The figure which shows transition of the temperature difference in 100 mm upper position from the surface of the surface layer in another comparative test of the heat island phenomenon suppression effect using the roadbed material and crushed stone concerning Example 2. FIG. The figure which shows the cone index test result of the roadbed material which concerns on Example 2. FIG. The figure which shows the cone index required for driving | running | working of a construction machine.

Recycled soil of the present invention is composed of one or more types of molten slag selected from general waste, industrial waste, and steel slag, and a molten slag granule adjusted to a particle size of 40 mm or less, water sludge, It is composed of a dehydrated cake obtained by dehydrating and drying one or more selected from sewage sludge and paper sludge, and a dehydrated cake granule adjusted to a particle size of 40 mm or less.

Dehydrated cake is a solidified sludge generated from the water purification plant or sewage treatment plant of each municipality, and is supplied stably on a municipal basis. The dehydrated cake meets certain safety standards and is neutral in pH 7-8 in aqueous solution.

Molten slag is produced by melting general waste (urban waste), industrial waste, etc. at high temperatures, decomposing and removing heavy metals and harmful substances, and cooling them, resulting in a significant reduction in volume. . By reusing the molten slag, it is possible to circulate resources. Molten slag is also neutral in pH 7-8 in aqueous solution, similar to dehydrated cake.

多数 There are many municipal waste melting treatment facilities throughout the country, and over 1 million tons of molten slag is produced annually, and is expected to be supplied stably in the present and future. The molten slag treated at the melting facility is JIS A5031 (general waste, sewage sludge or aggregated molten slag aggregate for incineration) and JIS A5032 (general waste, sewage sludge or incinerated ash) Quality control is performed based on the provisions of molten slag for roads). Therefore, the molten slag produced at the melt processing facility is a safety standard (elution standard and content standard for hazardous substances (cadmium, lead, hexavalent chromium, arsenic, total mercury, selenium, fluorine, boron)) Meet. Use of such molten slag as a raw material for soil is preferable from the viewpoint of safety.

FIG. 1 shows a procedure for manufacturing the recycled soil according to the present embodiment by mixing molten slag and dehydrated cake. Although FIG. 1 shows a production procedure for adjusting the particle size after blending the molten slag and the dehydrated cake, the particle size may be adjusted before blending the molten slag and the dehydrated cake.
The recycled soil according to the present embodiment is composed of molten slag granules and dehydrated cake granules. However, since the particle size may be adjusted at any stage of the manufacturing process, in the following description, molten slag and molten slag as raw materials are used. The granular materials are collectively referred to as “molten slag”, and the dehydrated cake and dehydrated cake granules are collectively referred to as “dehydrated cake”. Accordingly, the blending ratio of recycled soil and the like shown in the following examples is the ratio of the molten slag granule and the dehydrated cake granule.

In FIG. 1, the steps enclosed by the broken line (carrying raw materials from the gravel collection site, dewatered cake dry pulverization, sand powder dry pulverization) are performed as necessary. For example, the raw material is brought in from the gravel collection site when sand powder or the like is added to the recycled soil as a silt component.
Moreover, it is not necessary to perform the process (mixing test (soil test)) surrounded by the two-dot chain line in FIG. 1 every time. That is, it can be omitted when the properties of the compounded material such as molten slag, dehydrated cake, and sand powder are the same.

The general characteristics and particle size characteristics of recycled soil produced by changing the mixing ratio of molten slag and dehydrated cake according to the procedure shown in FIG. FIG. 2 shows test items related to general characteristics and particle size characteristics.

FIG. 3 shows the test results regarding the general characteristics and particle size characteristics of the recycled soil according to this example. In the test, five types of recycled soil were used in which molten slag and dehydrated cake were blended at a ratio of 3: 7 to 8: 2. The upper column of FIG. 3 shows the mixing ratio of molten slag and dehydrated cake of recycled soil (A) to (E) (molten slag: dehydrated cake), and the test date and test result are shown below. From the values of natural moisture content, all of the recycled soils (A) to (E) showed better water retention than the crushed stones and regenerated crushed stones used for comparison. Recycled soils (A) to (C), ( It can be seen that E) (a mixture of molten slag and dehydrated cake in a ratio of 3: 7 to 7: 3) has a natural water content of 10% or more, which is a particularly good measure of water retention.

Figure 4 shows the evaluation of water permeability characteristics of recycled soil (A) to (E). The evaluation of water permeability was made based on the results of three simple water permeability tests conducted each time. In the simple water permeation comparison test, 200 ml of recycled soil is put in a container, the surface is leveled, and lightly struck 25 times with a wooden stick with a diameter of 25 mm and a length of 180 mm. This was done by measuring the time to penetrate the recycled soil when 150 ml of water was poured.

From the results shown in FIGS. 3 and 4, recycled soil (A), (B), and (E) have excellent water permeability equivalent to or better than crushed stone and recycled crushed stone in addition to excellent water retention. I understand. In particular, recycled soil (A) (molten slag: recycled soil containing dehydrated cake in a ratio of 5: 5) and recycled soil (E) (molten slag: recycled soil mixed with dehydrated cake in a ratio of 3: 7) Excellent water retention and water permeability.
In general, recycled soil with good water permeability (fast water permeability) tends to have a low water content ratio. However, these recycled soils (A) and (E) have both excellent water permeability and water content, so if the surface layer contains a large amount of water, it quickly absorbs the water and the surface layer is dry. If it is, it can be said that it has an excellent humidity control property of supplying moisture.
Recycled soil (C) had excellent water retention, but its water permeability was inferior to recycled soil (A), (B), (E). However, water permeability can be improved by mixing silt content such as sand powder and crushed stone powder, which has been conventionally blended in soil, with recycled soil (C).

The soil for planting according to Example 1 is composed of one or more types of molten slag selected from general waste, industrial waste, and steel slag, and a molten slag granule having a particle size adjusted to 20 mm or less, One or a plurality of types selected from water sludge, sewage sludge, and paper sludge are dehydrated and dried, and are blended with dehydrated cake granules whose particle size is adjusted to 20 mm or less. The reason why the particle size of the molten slag granule and the dehydrated cake granule was set to 20 mm or less was that the soil for planting according to Example 1 had a size suitable for growing plants and the like due to the pores between these granules. It is considered to have perforations.

The procedure for producing the soil for planting according to Example 1 is almost the same as the procedure for producing the recycled soil shown in FIG. 1, but when performing a density test or the like, a particle size test is also performed as necessary.

In order to evaluate the characteristics of the soil for planting according to Example 1, a gardenia planting experiment, a natural turf growth test, a lettuce cultivation test, and a Seikoin radish cultivation test were conducted. Each result will be described in turn.

The planting experiment of gardenia was carried out by planting gardenia in a planting pot having a diameter of 15 cm and a depth of 25 cm. Planting experiments were conducted for 13 months from December 2009 to December 2010.

As soil used for the planting experiment, soil A was prepared by mixing molten slag, dehydrated cake, and sand silt in a ratio of 45:45:10 according to the above-described manufacturing procedure. In addition, soil B was mixed with soil A and molten slag at a ratio of 90:10 to increase the ratio of molten slag, and soil A and molten slag was mixed at a ratio of 80:20 to further increase the ratio of molten slag. Soil C, soil A mixed with 20 g of granular chemical fertilizer Wood Ace (trade name; manufactured by Mitsubishi Chemical Aguri Co., Ltd.), soil D, soil A mixed with 40 g of wood ace and soil A, soil A with 60 g of wood ace Each soil F was prepared. Furthermore, as a soil for planting for comparison, Green Foster LT (trade name, manufactured by Toyota Roof Garden Co., Ltd.) was used. Green foster LT is an excellent planting soil having the characteristics shown in FIG. Hereinafter, Green Foster LT is referred to as comparative soil 1.

For each of soil A to soil F and comparative soil 1, 5 strains were cultivated in total, and the volume was measured every month. The volume is defined as the product of the major axis, minor axis, and tree height. did. The measurement results for each month are shown in FIG. In addition, the individual number of each strain is shown in FIG.

Based on the above measurement results, the volume average of 5 strains grown in each soil was calculated, and the growth average of each month was calculated by subtracting the volume average at the beginning of planting. For any of the soils A to F, good gardenia growth results comparable to or higher than those of the comparative soil 1 were obtained. FIG. 7 shows changes in the volume of gardenia grown in soil A, soil E, and comparative soil 1.
From FIG. 7, it can be seen that soil A and soil E exhibit better characteristics than comparative soil 1 particularly in summer. This is considered to be because soils A and E are particularly excellent in water retention during drying, among various characteristics required for planting soil.

After the planting experiment was completed, soil was collected from 11 of the 35 strains and examined for soil characteristics. FIG. 8 shows a test method for soil properties relating to the pH value and the content of active ingredients, and FIG. 9 shows the test results for each individual. Moreover, the result of having done the same test about the molten slag which is a raw material in a present Example, a dewatering cake, and sand powder is shown in FIG. Although the specific item which shows a remarkable correlation with the result of the said planting experiment is not seen, it is thought that each item has a favorable correlation mutually. The fact that the pH value of each soil is higher than the pH value of the raw material shown in FIG. 10 is due to the high pH value of the water used during the planting experiment.

Furthermore, FIG. 11 shows the results of examining the properties of the three-phase distribution, saturated hydraulic conductivity, effective moisture, and particle size composition of the soil collected from the above 11 strains. In addition, the soil name in FIG. 11 is based on a triangular coordinate (international law), and classifies soil based on a particle size composition. The particle size composition is expressed as a weight percentage for each predetermined particle size range with respect to the soil excluding gravel (particle size of 2.0 mm or more). The particle size of coarse sand is 0.2 mm to 2.0 mm, the particle size of fine sand is 0.02 mm to 0.2 mm, the particle size of silt is 0.002 mm to 0.02 mm, and the particle size of clay is 0.001 mm to 0.002 mm.

Furthermore, in order to evaluate the characteristics of the soil for planting according to this example, a nodule structure composition confirmation test and a water holding capacity comparison test were performed.

The soil structure composition confirmation test uses soil A, which is a natural sand soil that is widely used as a soil for planting, and a soil that is mixed with high-quality soil so as to have an aggregate structure suitable for planting. It was compared with soil premix (trade name, manufactured by Ecomax Co., Ltd.). The aggregate structure composition confirmation test was performed by an aggregate analysis method (wet sieving method) based on the soil environment analysis method. The result is shown in FIG.

The degree of aggregate formation is a percentage of the ratio of the mass of aggregates larger than the standard particle size divided by the mass of soil particles smaller than the standard particle size, and is a guideline for evaluating the aggregate structure of the soil for planting. Become. The soil showing a high degree of aggregate formation has large pores between the aggregates and small pores inside the aggregates, and is excellent in both water permeability and water retention. Moreover, in such soil, the activities of soil microorganisms and small soil animals are likely to be active, and the soil contains a large amount of nutrients necessary for the growth of plants and the like. As shown in FIG. 12, soil A has the highest numerical value at a standard particle size of 0.10 mm, and has a superior aggregate structure as compared with pure sand soil or soil premix.

Subsequently, a water holding capacity comparison test (JGS 0151) of the soil for planting according to this example was performed. In the water holding capacity comparison test, the soil A used in the above-mentioned gardenia planting experiment was used and compared with the true sand soil. The water holding capacity comparison test was performed by measuring the water content in a state where pF = 2.0 was applied by the pressure plate method and pF = 4.0 was applied by the centrifugal method. As shown in FIG. 13, it is understood that soil A has a water holding power superior to that of true sand soil in both measurements of pF = 2.0 and pF = 4.0.

Next, the growth test of natural turf performed using the planting soil according to this example will be described. In this test, natural grass was seeded in April 2011, and then its growth was observed until August 2011. The soil used is soil x in which molten slag and dehydrated cake are mixed at a ratio of 5: 5, soil y in which soil x and bark compost are mixed in a ratio of 9: 1, and ratio of true sand and bark compost in a ratio of 9: 1. 3 types of comparative soil 2 formulated with Comparative soil 2 is a general soil used for the growth of lawn and the like.

Explain the results of a natural turf growth test. Natural turf grew smoothly in soil x, soil y, and comparative soil 2. Therefore, in July 2011, natural turf growing on all soils was cut at a height of 3 cm, and the growth status was confirmed for another month. As a result, the density of the grown natural turf increased in the order of soil y, soil x, and comparative soil 2, and the blueness of the turf was also increased. From this, it was confirmed that the soil x and soil y of the present example using recycled materials as raw materials have soil characteristics equivalent to or better than the comparative soil 2 used as a general planting soil. .

In parallel with the natural turf growth test, a test was conducted to verify the suppression effect of the heat island phenomenon. The test period was from 14:00 on July 30, 2011 to 10:00 on August 8, 2011. During this period, the surface temperature of the lawn growing on each soil was measured every 60 minutes.

Explain the results of the heat island phenomenon suppression test. The maximum / minimum temperature measured during the test period was 49.0 ° C / 20.5 ° C for soil x, 51.0 ° C / 20.5 ° C for soil y, and 52.5 ° C / 21.5 ° C for comparative soil 2. The largest difference between the surface temperature of the lawn growing in soil x and soil y and the surface temperature of the lawn growing in comparative soil 2 occurred at 12:00 on August 6, 2011, The temperature difference was 3.0 ° C. At this time, the surface temperature of the lawn on each soil was 46.5 ° C. for soil x, 45.0 ° C. for soil y, and 48.0 ° C. for comparative soil 2. FIG. 14 is an excerpt of the transition of measured temperature from August 6, 2011 at 8:00 to August 8, 2011 at 10:00. From this, it was confirmed that the soil x and the soil y according to the present example have an excellent heat island suppression effect.

In parallel with the above test, a test was conducted to verify the effect of suppressing the heat island phenomenon when soil z containing 9: 1 ratio of molten slag and dehydrated cake was used as artificial turf filler (mesh sand). It was. The test filler was a two-layer filler in which soil z was spread on artificial grass and then covered with quartz sand. Moreover, the comparative filler was a filler in which only silica sand, which is a general artificial turf filler, was spread. In the test filler, the silica sand was spread on the soil z because the soil z is closer to black than the silica sand and easily absorbs heat, so the temperature difference caused by the color difference of the filler is avoided. Because. The test period was from 9:00 on July 29, 2011 to 10:00 on August 8, 2011. During this period, the surface temperature of the artificial turf with each filler was measured every 60 minutes.

Explain the results of the above test. The maximum / minimum temperature measured during the test period was 51.0 ° C / 20.5 ° C for the test filler and 53.5 ° C / 23.5 ° C for the comparative filler. The largest difference in measured temperature occurred between the surface temperature of the artificial turf with the test filler and the surface temperature of the artificial turf with the comparative filler at 15:00 on August 6, 2011. The temperature difference was 4.0 ° C. At this time, the surface temperature of the artificial turf coated with the test filler was 45 ° C., and the surface temperature of the artificial turf coated with the comparative filler was 49 ° C. FIG. 15 is an excerpt of the transition of the measured temperature from August 6, 2011 at 8:00 to August 8, 2011 at 0:00. From this result, it was confirmed that the soil x according to the present example exhibited the effect of suppressing the heat island phenomenon even when used as a lawn filler.

Furthermore, a lettuce cultivation test was conducted using the soil for planting according to this example. The lettuce cultivation test was divided into a preliminary test and a main test. First, in a preliminary test, we sown lettuce seeds in April 2011 and observed their growth until August 2011. The soil used was the same as in the natural turf growth test: soil x containing molten slag and dehydrated cake in a ratio of 5: 5, soil a containing soil x and bark compost in a ratio of 85:15, molten slag and dehydrated Soil x ′ containing cake and sand powder in a ratio of 45:45:10 and soil b containing bark compost in a ratio of 9: 1, soil c containing soil x ′ and bark compost in a ratio of 85:15 , Soil d in which soil x ′ and bark compost are mixed at a ratio of 8: 2, and comparative soil 3 (trade name “freshly picked vegetables” manufactured by Takii Seed Co., Ltd.). Comparative soil 3 is mixed with nitrogen, phosphoric acid, and potassium, which are the three elements of fertilizer, as well as trace elements such as magnesium (magnesium), boron, iron, and manganese, and slow-release fertilizer, and is adjusted to weak acidity. It is a high-quality planting soil for planting.

Explain the results of the preliminary cultivation test for lettuce. In all of soil x and soil a to soil d, germination of the same number or more as that of comparative soil 3 was observed. However, at the end of August when the test was completed, lettuce grown on soil a, soil b, and soil c grew to a level that could be harvested, but did not reach the growth status of comparative soil 3.

At the end of the preliminary test, lettuce roots grown on soil c and lettuce roots grown on comparative soil 3 were compared. As a result, it was confirmed that the lettuce roots grown in the soil c were not as wide as the lettuce roots grown in the comparative soil 3. This was presumed to be due to the fact that the soil became too tight with the passage of days and the root growth did not progress.

Next, in consideration of the results of the preliminary test, this test was performed using the improved soil. In this test, taking into account that the soil does not become too tight, recycled compost and bark compost, and soil improvement agent peat moss and perlite, chemical fertilizer Magamp K (trade name, manufactured by Hyponex Japan Co., Ltd.) New soils 1 to 11 were added as appropriate to soil x, and lettuce was cultivated for one month in July 2011. Soil 1 to soil 11 are each made by mixing 5,000 g of soil x with appropriate additives. The additive and addition amount of each soil and the soil characteristics are shown in FIG. When the growth state of lettuce in these soils was observed, the largest amount of lettuce grew in soil 8. This is thought to be due to the fact that the weight of soil 8 is relatively light compared to other soils, so that the root spread is improved compared to soil x and soil a to soil d used in the previous test. . Moreover, soil 8 became weakly acidic (pH 6.84) soil suitable for growing plants and the like by adding bark compost, rice husk and peat moss.

In addition, we conducted a nurturing test of Seigoin Daikon for one month in September 2011. The soil used was soil b used in the lettuce growth test, soil 8 with good results in the lettuce growth follow-up test, and comparative soil 3 (trade name “freshly picked vegetables”, manufactured by Takii Seed Co., Ltd.) It is. As a result of observation for one month, it was confirmed that the soil 8 had a growth situation equivalent to or higher than that of the comparative soil 3. That is, it was confirmed that the planting soil according to the present example was a soil capable of growing plants and the like at the same level or higher as the high-quality planting soil while using recycled materials as the main raw material. .

Here, soil x and soil 8 were analyzed in order to examine the effect of adding bark compost, rice husk and peat moss to soil x to make soil 8. The result is shown in FIG. From these comparisons, it was found that the addition of bark compost, rice husk and peat moss changed the pH value to slightly acidic, and the contents of nitrogen, phosphoric acid and potassium increased. These are all conditions suitable for the growth of plants, and the effect of appropriately adding additives to this example was confirmed.

Since the molten slag and dehydrated cake used as the raw material for the planting soil according to the present embodiment are manufactured at melting facilities and solidification treatment plants throughout the country, there are variations in the components in addition to the particle size distribution. Therefore, the soil for planting according to the present invention may be adjusted with pH by adding a soil improver, if necessary, or supplied with three elements (nitrogen, phosphate, potassium) as fertilizer. It is desirable to adjust the hardness of the soil or the like.
Examples of such soil conditioners include bark compost, rice bran compost, and peat moss blended in the above-described embodiments, rice straw and wheat straw, compost composed of these, livestock manure compost, rice chaff compost, corn cob compost, and tea shells. Organic waste recycling materials that are generated in large amounts on a daily basis, such as residues such as coffee grounds and potatoes, can be used.

A roadbed material according to Example 2 is a roadbed material including recycled soil according to the above-described example, and is composed of one or a plurality of types of molten slag selected from general waste, industrial waste, and steel slag. Is composed of molten slag granules adjusted to 40 mm or less, and dehydrated cake obtained by dehydrating and drying one or more selected from water sludge, sewage sludge, and paper sludge, and the particle size is adjusted to 40 mm or less It is a blend of dehydrated cake granules.

The procedure for manufacturing the roadbed material according to Example 2 in the factory is the same as the procedure for manufacturing the recycled soil shown in FIG. On the other hand, when a roadbed material is manufactured by mixing molten slag and dehydrated cake with existing soil (local soil, natural soil such as true sand or red soil) at an outdoor site, the procedure shown in FIG. 18 is performed. The roadbed material manufactured according to the procedure shown in FIG. 1 is checked for moisture content after completion and transported to the site by truck or the like. When the roadbed material is manufactured by the method of FIG. 18, the total amount of molten slag and dehydrated cake is the same as the existing soil in consideration of the soil quality of the existing soil as in the conventional case where the regenerated crushed stone is mixed into the existing soil. It is better to make it 15% to 50%.

1 and 18, the steps enclosed by broken lines (carrying in raw materials from the gravel collection site, sludge drying and grinding, sand powder drying and grinding) are performed as necessary. For example, the raw material is brought in from the gravel collection site when sand powder is mixed with the roadbed material. In addition, the sludge described in FIG. 18 is synonymous with the dehydrated cake described above.
Moreover, it is not necessary to perform the process (mixing test (soil test)) surrounded by the two-dot chain line in FIG. 1 every time. That is, it can be omitted when the properties of the compounded material such as molten slag, dehydrated cake, and sand powder are the same. On the other hand, when the roadbed material is manufactured by mixing molten slag and dehydrated cake into the existing soil according to the procedure shown in FIG. 18, the site changes because the properties of the existing soil are expected to differ from site to site. Each time a compounding test is performed.

In the above-mentioned test of recycled soil, various tests were performed in order to evaluate the performance when using recycled soil (A) and recycled soil (E) that showed excellent water retention and water permeability as roadbed materials. Hereinafter, a roadbed material using recycled soil (A) is referred to as a roadbed material (A), and a roadbed material using recycled soil (E) is referred to as a roadbed material (E).

First, for roadbed material (A), a water retention test (JGS 0151) was conducted on volcanic gravel, which has been used in the past. While volcanic gravel has superior water retention capacity compared to crushed stone and reclaimed crushed stone, the main production area is the Kyushu region, so when used for roadbed materials in areas other than Kyushu, such as the Tokyo metropolitan area and Kinki area, transportation costs are low. Therefore, it is an expensive roadbed material.

The water holding capacity comparison test was performed by the same method as the water holding capacity comparison test of the soil for planting. The result is shown in FIG. In terms of moisture content per unit volume (100 ml), volcanic gravel has a higher moisture content at pF = 2.0, while roadbed material (A) has a higher moisture content than volcanic gravel at pF = 4.0. It shows that it has better water holding capacity than volcanic gravel.
In addition, regarding the moisture content per unit weight (100 g) with the pressure of pF = 4.0 applied, the volcanic gravel shows a higher value than the roadbed material (A). This is because the dry weight of the volcanic gravel is lighter than the dry weight of the roadbed material (A), and therefore the amount of volcanic gravel increases when a unit weight (100 g) of roadbed material is collected. Actually, considering that the roadbed material is used in the determined location (volume), the roadbed material (A) showing a high value of moisture content per unit volume under the pressure of pF = 4.0. It can be said that has higher water retention capacity than volcanic gravel.

When the pH value of the roadbed material (A) was measured, it was pH = 6.94. Therefore, when the roadbed material (A) is used, there is no fear of adversely affecting the roadside trees or the like unlike the case where the recycled crushed stone showing strong alkalinity is used as the roadbed material.

A test for evaluating the suppression effect of the heat island phenomenon was conducted using the roadbed material (A). The effect of suppressing the heat island phenomenon is that using the above roadbed material (A) as the roadbed material (Example X) and crushed stone that is the conventional roadbed material under the same surface layer structure (Example X) ( It was evaluated by measuring how much temperature difference occurs between Comparative Example X) at the position 100 mm above the pavement surface and the pavement surface. Specifically, as shown in FIG. 20, the roadbed material of Example X or Comparative Example X having a thickness of 100 mm is disposed on the ground surface, and a molten slag of 30 mm thickness is further provided as the sand, and the upper surface layer. The temperature transition was measured and compared at the surface of the interlocking pavement and the position 100 mm above it.

Temperature measurement was performed every hour from 10:00 on September 1, 2010 to 8:00 on September 10, 2010. FIG. 21 shows the transition of the interlocking pavement surface temperature of Example X and Comparative Example X, and FIG. 22 shows the transition of the temperature at a position 100 mm above the interlocking pavement surface of Example X and Comparative Example X, respectively. 23 shows the temperature difference between the interlocking pavement surfaces of Example X and Comparative Example X (Comparative Example X-Example X), and FIG. 24 shows the position 100 mm above the interlocking pavement surfaces of Example X and Comparative Example X. The temperature difference at (Comparative Example X-Example X) is shown respectively. As is clear from FIG. 23 and FIG. 24, Example X shows a lower temperature at almost all times within the measurement period.

Especially, a remarkable temperature difference was confirmed at 10:00 and 16:00 on a sunny day. FIG. 25 shows the weather at 10:00 and 16:00 during the measurement period, and the temperature difference between the interlocking pavement surface and 100 mm above (Comparative Example X-Example X). It is considered that the road surface temperature starts to rise around 10:00 and the road temperature starts to fall around 16:00 in the day. It is judged that there is an effect that it is difficult to raise the road surface temperature and it is easy to lower it. That is, it can be evaluated that the roadbed material (A) has a greater effect of suppressing the heat island phenomenon than crushed stone.

The test for evaluating the suppression effect of the heat island phenomenon was also performed with a structure different from the above (Example Y and Comparative Example Y shown in FIG. 26). The temperature measurement period, measurement interval, and measurement position are the same as in the above test. Example Y has a structure consisting of a 100 mm thick roadbed material (A) disposed on the ground surface and a 100 mm thick surface layer material disposed above it, and Comparative Example Y is 100 mm thick disposed on the ground surface. It has a structure consisting of a crushed stone and a surface layer material with a thickness of 100 mm arranged above it. The surface layer material of Example Y is a mixture of molten slag, dehydrated cake, and sand powder in a ratio of 45:45:10 (hereinafter referred to as “surface layer material Y”) as in the above-described planting soil A. Yes, the surface material of Comparative Example Y is pure sand.

FIG. 27 shows the transition of the interlocking pavement surface temperature of Example Y and Comparative Example Y, and FIG. 28 shows the transition of the temperature at a position 100 mm above the interlocking pavement surface of Example Y and Comparative Example Y, respectively. FIG. 29 shows the temperature difference between the interlocking pavement surfaces of Example Y and Comparative Example Y (Comparative Example Y-Example Y), and FIG. 30 shows the position 100 mm above the interlocking pavement surface of Example Y and Comparative Example Y. The temperature difference at (Comparative Example Y-Example Y) is shown respectively. As is clear from FIGS. 29 and 30, even in this test, Example Y shows a lower temperature at almost all times within the measurement period.

Although the surface layer material Y used for the surface layer material of Example Y has better water retention than the pure sand soil used for the surface layer material of Comparative Example Y, it is closer to black than the true sand soil and easily absorbs heat. Therefore, in the experiment that the present inventor has conducted in the past, when the roadbed material is recycled crushed stone and the surface layer material is the surface layer material Y, the surface temperature particularly in the sunshine hours is the same as or higher than that of the comparative example Y. The tendency was easy. Nonetheless, Example Y showed a lower temperature transition than Comparative Example Y, and the roadbed material (A) still has a better heat island effect suppression effect than crushed stone, It can be evaluated as excellent as a roadbed material for playgrounds and various stadiums.
In addition, it is known that when artificial turf is installed on the surface of a surface material such as a sports field, the temperature is likely to rise. Depending on the conditions, the surface temperature reaches 60 ° C to 70 ° C. Even if the above-mentioned roadbed material (A) is used as the roadbed material for such a playground, the effect of suppressing the heat island phenomenon can be expected to be effective.

Subsequently, using the roadbed material (E), a soil compaction test by tamping (JIS A1210, JGS-0711: conducted by test method Eb) and a compacted soil cone index test (JIS A1228, JGS 0716) And compaction properties were evaluated.

As a result of the compaction test of the soil by tamping, the optimum water content ω _opt of the roadbed material (E) was 18.6%, and the maximum dry density ρ _dmax was 1.643 g / cm ³ . The optimum water content ratio and the maximum dry density mean the water content ratio and density in a state where the road base material (E) is best tightened when it is compacted.

The compacted corn index test was performed using four types of samples 1 to 4 (moisture content: 9.8%, 13.2%, 16.1%, 19.4%) with different moisture content of the roadbed material (E). The result is shown in FIG. The Cone Index represents the soil property that indicates whether the construction machine is good or bad. The cone index corresponds to the contact pressure of each construction machine as shown in FIG. 32, and is used as a scale for determining whether or not the construction machine can travel, and is a standard indicating the firmness of the roadbed material. The cone index qc (kN / m ² ) is the penetration resistance force that acts on the bottom of the cone when the cone penetrometer is continuously pushed from the ground surface to 5 cm, 7.5 cm and 10 cm at a penetration rate of 1 cm / s ( The average value of kN) is obtained and divided by the bottom area (3.24 cm ² ) of the tip cone (penetration resistance / bottom area of the tip cone). As shown in FIG. 31, since the cone index of all samples 1 to 4 of the roadbed material (E) exceeds the cone index of the dump truck shown in FIG. 32, the roadbed material (E) runs on the dump truck. It can be seen that it is as robust as possible.
From the above, it can be said that the roadbed material (E) is sufficiently solid to be used as a roadbed material used in outdoor facilities such as school playgrounds, various stadiums, parks, sidewalks and the like.

The above embodiment is premised on the use for roadbed materials used for sidewalk pavements and ground pavement roadbeds, but by mixing recycled crushed stone with them, it can be applied to roads. Can be given.

The effect of improving the firmness of the roadbed material by mixing recycled crushed stone with the above roadbed material (E) was verified. In this verification, the above-mentioned soil compaction test (JIS A1210, JGS 0711: Test method Eb) was performed using roadbed material (E ') in which roadbed material (E) and recycled crushed stone were mixed at a ratio of 80:20. ) And the CBR test (JIS A1211, JGS 0721).
As a result of the compaction test of soil by tamping, the optimum water content ω _opt of the roadbed material (E ′) was 12.5%, and the maximum dry density ρ _dmax was 1.789 g / cm ³ . As a result of the CBR test, the 95% corrected CBR value was 50.4%. This CBR value exceeds the revised CBR value of 40% for recycled crusher run, which is the lower roadbed material for roads. Therefore, if the recycled crushed stone is mixed with the roadbed material (E), it is possible to provide the solidity that can be used as a roadbed material for parking lots and roads.

As with the conventional roadbed material, the roadbed material can be provided with new characteristics by adding sodium chloride, natural rice husk, natural scallop shell, and natural small pumice to the roadbed material of the present invention.
When sodium chloride is added to the roadbed material of the present invention, the roadbed material can be prevented from freezing and the growth of weeds can be suppressed. Sodium chloride may be blended in a proportion of 1 m ² per 2 ~ 4 kg. If rice husk or scallop husk is blended, the road base material can be prevented from freezing and the growth of weeds can be prevented, and the water retention and humidity control properties of the road base material can be improved. Furthermore, if pumice is blended, the water retention and humidity control properties of the roadbed material can be further improved.

Modified example

The recycled soil of the present invention can be applied to soil for planting and roadbed materials, as well as surface soil with a ground pavement structure. When used as such ground soil, dehydrated cake granules and molten slag granules are blended in a ratio of 4: 6 to 6: 4, and the particle size of both granules is 9.5 mm or less. It is preferable to add a silt such as sand powder or crushed stone powder so that the total fine particle content is 10 to 18%.
Furthermore, when used as soil for ground, it is better to adjust so that 90% or more of the total particle size is 2 mm or less, and it is also advisable to mix dehydrated cake granules and molten slag granules in a ratio of 5: 5. .
By adjusting as described above, it is possible to obtain an ideal ground soil having elasticity suitable for the ground soil and having an excellent degree of compaction.
In addition, similar to the above-mentioned roadbed material, by adding sodium chloride, natural rice husk, natural scallop shell, natural small pumice, it adds functionality such as anti-freezing, suppression of weed growth, and improvement of water retention and humidity control. be able to.

Claims (18)

1. a) A molten slag granule composed of one or more types of molten slag selected from general waste, industrial waste, and steel slag, and having a particle size adjusted to 40 mm or less,
   b) Recycling consisting of dehydrated cake made by dewatering and drying one or more selected from water sludge, sewage sludge, and paper sludge, and dehydrated cake granules adjusted to a particle size of 40 mm or less soil.
2. The recycled soil according to claim 1, wherein the molten slag granules and the dehydrated cake granules are blended in a ratio of 1: 9 to 9: 1.
3. The recycled soil according to claim 1 or 2, wherein the molten slag granules and the dehydrated cake granules are blended in a ratio of 3: 7 to 7: 3.
4. A soil for planting comprising the recycled soil according to any one of claims 1 to 3,
   A soil for planting, wherein the molten slag granule is adjusted to a particle size of 20 mm or less, and the dehydrated cake granule is adjusted to a particle size of 20 mm or less.
5. The planting soil according to claim 4, wherein the molten slag granule and the dehydrated cake granule have a aggregate structure.
6. The planting soil according to claim 4 or 5, wherein a silt content of 0% to 20% is blended with respect to a total amount of the molten slag granules and the dehydrated cake granules.
7. The planting soil according to any one of claims 4 to 6, wherein at least one of bark compost, rice bran compost, and peat moss is mixed.
8. The planting soil according to any one of claims 4 to 7, wherein a recycling material of organic waste is mixed.
9. A lawn filler containing the recycled soil according to claim 1 or 2.
10. The roadbed material containing recycled soil according to any one of claims 1 to 3, which is used for a roadbed having a pavement for a sidewalk or a ground pavement.
11. The roadbed material according to claim 10, wherein 0% to 20% of crushed stone or regenerated crushed stone is blended with respect to a total amount of the molten slag particle material and the dehydrated cake particle material.
12. The roadbed material according to claim 10 or 11, wherein the silt content is blended so that the total fine particle content is 3% to 18%.
13. The existing soil is blended so that the total amount of the molten slag granules and the dehydrated cake granules is 15% to 50% of the existing soil. Roadbed material.
14. The roadbed material according to any one of claims 10 to 13, wherein at least one of sodium chloride, natural rice husk, natural scallop shell, and natural small pumice is blended.
15. A ground soil containing the recycled soil according to any one of claims 1 to 3,
    The molten slag granules and the dehydrated cake granules are blended in a ratio of 4: 6 to 6: 4, the molten slag granules are adjusted to a particle size of 9.5 mm or less, and the dehydrated cake granules are 9.5 mm in diameter. A soil for ground characterized by being adjusted to the following and blended with silt so that the total fine grain content is 10% to 18%.
16. The ground soil according to claim 15, wherein 90% or more of the whole is adjusted to have a particle diameter of 2 mm or less.
17. The soil for ground according to claim 15 or 16, wherein 1.5 to 4 times the amount of natural soil is blended with respect to the total amount of the molten slag granules and the dehydrated cake granules.
18. The ground soil according to any one of claims 15 to 17, wherein at least one of sodium chloride, natural rice husk, natural scallop shell, and natural small pumice is blended.

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