KR20060093526A - Soil for road-repairing using water-sludge - Google Patents

Abstract

The present invention relates to subgrade soils for road works using purified water sludge, wherein the purified water sludge is dehydrated at a water treatment plant of less than 70% by weight (wt%) to form a blending ratio of 9 to 15 wt%; Soil with 70% or less of the total particle size distribution, the moisture content of which is less than 13 wt%, and the mixing ratio of 85-91 wt% is passed through the No.200 sieve; Soil consisting of a surfactant as a main component to remove the moisture adsorbed on the mixed soil by adding 0.005 ~ 0.015 wt% to the mixed soil made by mixing the purified sludge and the soil at the same time Stabilizers; Characterized in that it comprises a, it is possible to reduce the cost of treating the purified water sludge by recycling the purified water sludge, it is possible to prevent the environment from being contaminated by the purified water sludge.

Water purification sludge, soil, soil stabilizer, road construction, subsoil.

Description

Road subgrade soil using water purification sludge {SOIL FOR ROAD-REPAIRING USING WATER-SLUDGE}

1 is a manufacturing process chart for manufacturing subgrade soil for road works using water purification sludge according to the present invention.

The present invention relates to a subgrade soil for road works using purified water sludge, and in particular, a predetermined amount of soil stabilizer is added to a mixed soil made by mixing sludge and soil generated during water treatment to remove moisture adsorbed on the mixed soil and at the same time. To prevent re-adsorption of moisture into the water and to recycle the purified water sludge as described above, thereby reducing the cost of treating the purified water sludge, and to prevent contamination of the environment due to the purified water sludge. It relates to subgrade soil for road works using sludge.

In general, purified water sludge is a mud state that is generated by sedimentation of water in the water treatment process, and most of them are disposed of in landfills or dumped at sea.

However, the purified sludge as described above has a lot of difficulties in securing the landfill due to problems such as inhibiting the stability of the landfill due to the high water content, and soil and groundwater contaminated by leachate generated during landfill treatment.

In addition, in order to transport the purified water sludge to the dumping point for ocean dumping on the high sea, a lot of transportation costs are required, and there is a problem of polluting the ocean.

In order to solve the above problems, as a method for recycling purified water sludge, Patent Publication No. 10-0242766 entitled 'Soil composition and its manufacturing method mainly using water purification sludge', and Patent Publication No. 10 Although the 'method of manufacturing a soil improver using water sludge' has been proposed in -0274532, the method of using purified water sludge as a subgrade soil for road works has not been proposed yet due to various problems as described below. It is true.

In other words, Article 46, Clause 3 of the Enforcement Regulations of the Waste Management Act stipulates that purified water sludge dehydrated and dried with moisture content of 70% or less can be mixed with more than 50% of soil and used as a fill material, auxiliary base material, road substrate material, etc. When the soil and purified sludge are combined to satisfy the Waste Management Act, the water content can be reduced, but the moisture in the rainy season can be reduced to the surface of the soil and purified sludge particles due to the clay. Sponge occurs due to the expansion of the soil and the purified water sludge caused by the deterioration of the strength of the road pavement layer is damaged the road and thus the problem of having to restrict the entry and passage of the traffic vehicle.

The present invention has been made to solve the above problems, the object is to remove the moisture adsorbed on the mixed soil made by mixing soil and purified sludge and to prevent the re-adsorption of moisture in the mixed soil It is to provide a subgrade soil for road works using water purification sludge, which can prevent the road from being damaged due to the reduced strength of the road pavement layer.

In addition, another object of the present invention is to reduce the cost of treating the purified water sludge by recycling the purified water sludge generated during the purified water treatment, and to prevent the environment from being contaminated by the purified water sludge. To provide subgrade soil for road works using water purification sludge.

Road works for subgrade soils using purified water sludge according to the present invention for achieving the above object, the water content is dewatered to 70% by weight (wt%) or less in the purified water treatment plant to form a blending ratio of 9 to 15 wt% and ; Soil with 70% or less of the total particle size distribution, the moisture content of which is less than 13 wt%, and the mixing ratio of 85-91 wt% is passed through the No.200 sieve; Soil consisting of a surfactant as a main component to remove the moisture adsorbed on the mixed soil by adding 0.005 ~ 0.015 wt% to the mixed soil made by mixing the purified sludge and the soil at the same time Stabilizers; Characterized in that it comprises a.

In addition, the surfactant is preferably made of sulfonated oil (Sulphonated oil).

Hereinafter, the subgrade soil for road construction using purified water sludge according to the present invention will be described in detail.

The subgrade soil for road works using purified water sludge according to the present invention is characterized in that the purified water sludge, soil, and soil stabilizer are formulated.

First, the subgrade soil refers to the soil used for the roadbed, and the subbed refers to the soil portion of about 1 m in thickness of the pavement on the road. This part is 1m.

The barrier layer for preventing invasion of the roadbed soil into the roadbed, and the replacement part of the roadbed soil in the soft ground are also included in the roadbed.

In order for the pavement not to be destroyed and to play its role, it is necessary to pay attention to not only the pavement but also the portion under it, and the hearth is the basis for determining the thickness of the pavement.

The subgrade soils as described above should conform to <Table 1>, which is the standard of the subgrade material in the road construction standard specification of the Ministry of Construction and Transportation.

In Table 1, the plasticity index refers to a range in which soil may exist in a plastic state in a natural state, and the modified CBR refers to a value representing the strength of subgrade materials that can be expected in the field. Based on the results.

The compaction test is KS F 2312, the immersion expansion test is KS F 2320, the penetration test is performed by the test method according to the Korean Industrial Standards (KS), such as KS F 2307, so the detailed description thereof will be omitted.

On the other hand, the purified water sludge is a mud state generated by sedimentation of water in the water purification process, and is composed of a large amount of water, clay, sand, organic matter, and a hydrate of a flocculant, which will be described later. In the embodiment of the water treatment plant, a certain amount of water was dehydrated and used in accordance with the waste management law.

The soil is generally gravel (76 ~ 4.75mm), sand (4.75 ~ 0.05mm), silt (0.05 ~ 0.002mm), clay (0.002 ~ 0.001mm), colloid ( Less than 0.001 mm), and in Examples 1 to 3 of the present invention to be described later, soil suitable for the criteria of the road material of the road construction standard specification of the Ministry of Construction and Transportation of Table 1 was used, and in Examples 4 and 5, By using the soil that does not meet the standards of the roadbed material of the road construction standard specification of the Ministry of Construction and Transportation, Table 1, the characteristics of the purified sludge and blending was analyzed.

In the present invention, it is essential that the characteristics of the mixed soil including water purification sludge mixed with general soil satisfy the criteria of the roadbed material of the road construction standard specification of the Ministry of Construction and Transportation. The test was conducted by mixing the purified water sludge and the soil stabilizer to be described later in various soils in a variety of mixing ratios, as shown in Examples below.

In addition, the soil was used that the water content is less than 13 wt%, because the optimum water content range is about 13 wt% in the case of Masato.

If the water content is 13 wt% or more, the optimum water content condition when mixing with purified water sludge is not satisfied, so it must be dried naturally or after drying in a drying furnace.

No. above The 200 sieve is a test sieve according to the KS standard and means that the diameter of the body is 0.075 mm. 4 sieves say that their diameter is 4.75mm.

On the other hand, the soil stabilizer is to prevent the re-adsorption of moisture in the mixed soil at the same time is added to the mixed soil made by mixing the soil and purified water sludge to remove the moisture adsorbed on the mixed soil, mainly surfactant It is made with a main component, the surfactant is characterized in that it comprises a sulfulated oil (Sulphonated oil).

That is, the soil stabilizer is a chemical synthetic material comprising sulfide oil, which is a kind of surfactant, and an active ingredient that continuously maintains the activity of the sulfide oil. The sulfide molecule is insoluble in most nonpolar organic solvents, but is insoluble in water. It is composed of a hydrophilic head that is completely dissolved or mixed well, and a hydrophobic tail that is composed of a combination of carbon and hydrogen atoms and is insoluble in water. Is commercialized.

The sulfide oil as described above interacts with the soil and sludge particles blended in an appropriate amount to remove moisture adsorbed on the mixed soil in which the soil and sludge are mixed, and prevents the water from resorbing the mixed soil.

That is, the cations with high mobility on the surface of soil and sludge particles bind to the anions of the hydrophilic head of sulfided oil and are fixed in place, and are sealed by sulfide oil molecules to prevent the formation of a solvent compound by combining with moisture.

In addition, once the head of the sulfide molecule is combined with the soil and sludge particles, the hydrophobic tail of the sulfide molecule is directed away from the surface of the soil and sludge particles, thereby forming an oily protective layer around the soil and sludge particles. .

Therefore, the moisture is repelled by the hydrophobic tail, so that it is naturally isolated from the soil and sludge particles without applying mechanical pressure, and due to the above action, the soil and sludge particles are arranged in a very dense state and the soil and sludge The hydrophobic protective layer formed around the particles can not penetrate even a small amount of moisture.

In addition, since the moisture can move freely to the space between the soil and sludge particles coated with a hydrophobic protective layer, the soil and sludge are blended because moisture is easily evaporated by natural evaporation and is not resorbed on the surface of the soil and sludge particles. The stability of the mixed soil can be maintained continuously.

In order to obtain the above effects, in the present invention, the purified sludge, the soil, and the soil stabilizer were blended in various compounding ratios, and the following examples were performed based on the test method according to the KS standard.

Example 1

The purified sludge was dehydrated with a water content of 67.1 wt%, and the soil had a distribution of 9.8% of fine particles passing through No.200 sieve and a water content of 5.66 wt% in the AASHTO classification method described below. The non-baked thing classified into A-3 by the above was used.

As can be seen in Example 1, the soil mixing ratio of 85.7 wt% or more and the mixing ratio of the purified water sludge is 14.3 wt% or less, adding 0.01 wt% of the soil stabilizer, and then mixes the road of the Ministry of Construction and Transportation The plasticity index (less than 10) and the modified CBR (more than 10) can be satisfied in the standards of road materials.

Example 2

The purified sludge was dehydrated with a water content of 69.5 wt%, and the soil had a distribution of 14.3% and a water content of 11.4 wt% in the AASHTO classification method described below. The plasticity index classified as A-2 was used as 6.1%.

As can be seen in Example 2, the soil mixing ratio of 85.7 wt% or more and the mixing ratio of the purified sludge is 14.3 wt% or less, and adding 0.01 wt% of the soil stabilizer, and then mixes the roads of the Ministry of Construction and Transportation The plasticity index (less than 10) and the modified CBR (more than 10) can be satisfied in the standards of road materials.

Example 3

The purified sludge was dehydrated at a water content of 68,5 wt%, and the soil had a 22.8% distribution of fine particles passing through a No.200 sieve and a water content of 10.3 wt% in the total particle size distribution. The plasticity index classified as A-2 by the classification method was used as 7.5%.

As can be seen in Example 3, when the mixing ratio of soil is 85.7 wt% or more and the mixing ratio of purified water sludge is 14.3 wt% or less, and 0.01 wt% of the soil stabilizer is added, the mixing is carried out by the Ministry of Construction and Transportation. The plasticity index (less than 10) and the modified CBR (more than 10) can be satisfied in the standards of road materials.

Example 4

The purified sludge used was dehydrated with a water content of 69.6 wt%, and the soil had a distribution of 42.3% and a water content of 11.3 wt% in the AASHTO classification method described below. The plasticity indexes classified as A-4 and A-5 by 9.4% were used.

As can be seen in Example 4, the soil mixing ratio is 87.5 wt% or more, and the mixing ratio of the purified sludge is 12.5 wt% or less, and the soil stabilizer is added in 0.01 wt%. The plasticity index (less than 10) and the modified CBR (more than 10) can be satisfied in the standards of road materials.

Example 5

The purified sludge used was dehydrated with a water content of 69.1 wt%, and the soil had a distribution of 68% of the fine particles passing through No.200 sieve and a water content of 12.95 wt% in the AASHTO classification method described in Table 2 below. The plasticity indexes classified as A-6 and A-7 by 15.3% were used.

As can be seen in Example 5, the soil mixing ratio is 90.9 wt% or more, and the mixing ratio of the purified sludge is 9.1 wt% or less, and 0.01 wt% of the soil stabilizer is added. The plasticity index (less than 10) and the modified CBR (more than 10) can be satisfied in the standards of road materials.

To summarize the results of Examples 1 to 5, the purified sludge is 9-15 wt%, the soil is 85-91 wt% in order to satisfy the road material standards of the road construction standard specification of the Ministry of Construction and Transportation of Table 1 , The soil stabilizer is preferably blended in 0.005 ~ 0.015 wt%.

In addition, when the soil and the purified sludge and the soil stabilizer are combined in the above-described ratio, it can be used as subgrade soil, but in order to secure economic feasibility and to process a large amount of purified sludge in a short period of time, sandy soil will be more efficient than clay soil.

On the other hand, the manufacturing process for producing subgrade soil for road works using water purification sludge according to the present invention is a collection step, the classification step of the soil, the water content test step, the mixing ratio determination step, the mixing step as shown in FIG. And a quality inspection step and an export step.

The collecting step is a step of collecting the sludge generated in each water treatment plant in a predetermined area with a facility that does not leak leachate, collecting the soil at the construction site or the pit site, and the step of classifying the soil as the next step. Soil classification step is to classify the soil collected in the collection step based on the AASHTO classification method.

The AASHTO classification method is a method of classifying according to the particle size and group index of the soil, and is shown in Table 2 below.

Soil and purified sludge classified as described above is subjected to a water content test step, wherein the water content test step is such that the purified water sludge is less than 70% to comply with the waste management law regulations, and when the soil moisture content is 13% or more, natural drying This step is to dry or in a drying furnace.

As a next step, a compounding ratio determination step is performed, in which the compounding ratio is determined so that the water content of the purified water sludge and soil is optimal, and the blending ratio of the soil stabilizer added thereto is also determined.

After the optimum blending ratio is determined as described above, the purified sludge, the soil and the soil stabilizer are added to a high speed blender and subjected to a blending step of blending for 1 to 2 minutes.

When the formulation is made as described above, a quality inspection step is carried out. In this step, the water content test, the compaction test, and the like are performed based on the KS standard.

When manufactured by the manufacturing process as described above and passed in the quality inspection step, subgrade soil for road construction using purified water sludge according to the present invention is subjected to the carrying out step taken out to the construction site.

According to the subgrade soil for road works using purified water sludge according to the present invention as described above, a predetermined amount of soil stabilizer is added to the mixed soil made by mixing sludge and soil generated during the treatment of purified water sludge and adsorbed to the mixed soil. At the same time to remove the moisture to prevent the re-adsorption of moisture in the mixed soil has the effect that the road pavement layer is reduced in strength can be prevented from breaking the road.

In addition, it is possible to reduce the cost of treating the purified water sludge by recycling the purified water sludge, it is possible to prevent the environment from being contaminated by the purified water sludge.

Although the present invention has been described with reference to the embodiments, it may be said to be exemplary, and those skilled in the art may devise various modifications and equivalent embodiments therefrom, such equivalent embodiments. It is also very natural that it should be seen as included within the claims of the present invention. Therefore, the true scope of protection of the present invention should be determined only by the appended claims.

Claims (2)

Water purification sludge which is dehydrated to 70 wt% or less (wt%) in a water treatment plant to form a blending ratio of 9 to 15 wt%; Soil having a fine particle passing through a No. 200 sieve of 70% or less of the total particle size distribution, having a water content of less than 13 wt%, and a blending ratio of 85 to 91 wt%; Soil consisting of a surfactant as a main component to remove the moisture adsorbed on the mixed soil by adding 0.005 ~ 0.015 wt% to the mixed soil made by mixing the purified sludge and the soil at the same time Stabilizer; Subgrade soil for road construction using purified sludge, characterized in that it comprises a. The method of claim 1, The surfactant is subgrade soil for road works using purified sludge, characterized in that it comprises a sulfonated oil (Sulphonated oil).

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