KR20180051840A - Instillation material and method using the same - Google Patents

Abstract

The present invention relates to a nontoxic ground grouting material not containing cement and a ground reinforcement method using the same and, more specifically, to a nontoxic ground grouting material not containing cement, utilizing high-calcium ash discharged from a circulating fluidized bed boiler of an in-furnace desulfurization type and sodium sulfate, which is a by-product of a desulfurization process of ironworks, as an alkali and sulfate complex activator, and utilizing fine powder of natural mineral as a filler in order to exhibit latent hydraulic activity of blast furnace slag powder; and a ground reinforcement method using the same. According to the present invention, the ground grouting material comprises: 0.5 to 500 parts by weight of the high-calcium ash discharged from an in-furnace desulfurization type circulating fluidized bed boiler, wherein CaO content is 15 to 70 weight percent and SO_3 content is 3 to 30 weight percent with respect to 100 parts by weight of blast furnace slag powder; 0.1 to 100 parts by weight of sodium sulfate generated as a by-product of a desulfurization process of ironworks, wherein Na_2O content is 10 to 50 weight percent and SO_3 content is 10 to 50 weight percent; and 5 to 500 parts by weight of a natural mineral filler, which is any one or a mixture of two or more selected from the group consisting of limestone powder, feldspar powder, silica powder, granite powder, and dolomite powder pulverized by a particle size of 50 μm or less.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-toxic ground filler material containing no cement and a ground reinforcement method using the same.

The present invention relates to a non-toxic groundfill material containing no cement and a ground reinforcement method using the same. More specifically, the present invention relates to a high calcium soft material discharged from a circulating fluidized bed boiler in a furnace in order to exhibit potential hydraulic properties of a blast furnace slag fine powder. Which is a byproduct of desulfurization process of steelworks, as a composite stimulant of alkali and sulfate, and using natural mineral fine powder as a filler, and a ground reinforcement method using the same.

During the use of civil engineering and architectural structures, it is often necessary to reinforce the foundation and reinforcements due to tunnel construction, expansion or remodeling, change of purpose, increase of load.

The grouting method is used as a method for improving the ground which is expected of these problems and as a means for eliminating the safety problems such as order and reinforcement in constructing any objects.

The chemical solution injection method at the time of grouting construction injects the filling material such as cement liquid into the soft ground by the pressure of the pump to fill the pores or cracks in the ground to prevent the water from flowing out or to harden the ground layer by hardening And a chemical solution such as a cement liquid, a mortar liquid or a water glass liquid is used as an injection material.

Therefore, the chemical solution injection method has a complex effect such as prevention of scarring by increasing the strength of the ground by injecting a solution liquid and a solution-type chemical solution, which originally has fluidity but can be solidified after a predetermined time, Is one of the improvement methods of the ground that expects.

In general, cement is used as the main binder in the chemical solution injection method for reinforcing ground reinforcement, which causes environmental pollution caused by strong alkali and hexavalent chromium in the ground and excessive volume shrinkage occurs in the course of hydration reaction . In particular, cement must contain hexavalent chromium because the cement kiln is made of refractory clay bricks at the shear part of the low temperature furnace, and the temperature is high and the wear due to the friction of the clinker and the chemical reaction A mag-chrome brick containing magnesia and chromium is used at the rear end portion. In this process, chromium contained in the refractory bricks is known to be contained in the process of clinker formation.

Several techniques have been proposed to improve the problem of using such conventional cement as an injection material for grouting. For example, Korean Patent Registration No. 10-0699430 discloses a technique in which the occurrence of bleeding is reduced by adding cement as a main material and aluminum sulfate as a flocculant to grout (liquid A) containing bentonite, a dispersant and a retarder as an admixture, (B solution) to B solution (Solution A) to give expandability by using the foaming effect due to the chemical action of aluminum powder and cement.

However, the bentonite presented in this technology is also a natural product that is not available in Korea, and it is an expensive product which is dependent on the whole import. Aluminum powder is a fine particle and light weight property, There is a concern that even when it is used as a foaming agent in mortar, it is a substance to be handled in a limited work space provided with a dustproof facility and has a small specific gravity, which may cause a problem of not mixing with bentonite when producing a suspension mixed with water.

Further, in Korean Patent No. 10-0886220, a filling material (liquid A) is composed of a mixture of portland cement or portland cement and blast furnace slag cement, and the quick-setting (liquid B) is a mixture of sodium silicate and an acidic chemical liquid Technology.

This technique is a technique to neutralize the acid solution mixed with acidic solution to lower the alkali of sodium silicate used as a quick-setting agent, but the mixing ratio of portland cement and blast furnace slag cement is not presented, and cement is the main material It is not different from the existing technology.

Korean Patent No. 10-0834923 also discloses a technique in which cement mortar is used as a grouting filler and mortar has a water mixing ratio of 65 to 70% and a slump of 5 to 8 cm. Generally, cement mortar is used for various purposes such as plastering, wall-wicking, and fire-proofing. The composition of the mortar varies depending on the type of mortar. The composition of the mortar used as the injection material is not precisely shown, can do.

Also, in Korean Patent No. 10-0804807, 35 to 65% of a quick-setting component pulverized to have a powder degree of 4,500 to 5,500 cm 2 / g, 15 to 30% of a calcium sulfoaluminate powder, A filler composition (A) comprising 50 to 70% of cement powder and 5 to 15% of anhydrous gypsum, 5 to 15% of a gypsum plaster, 5 to 15% of loess powder, 3 to 10% of a reaction modifier, and 0.3 to 1.0% , And a microcement composition (B) composed of 30 to 50% slag fine powder.

The micro cement proposed by this technology generally means a product having a powder degree of 6,000 cm 2 / g or more. Although it is quite expensive, it is used as a material for filling microcracks in a chemical solution injection method in which only the heat part is injected without disturbing the paper sheet It is common. In addition, there are 7 kinds of raw materials in the case of the water - dispersible material (liquid A), so it is considered that there are many problems in manufacturing the product for practical use.

Also, in Korean Patent No. 10-1402877, it is disclosed that 55 to 65 wt% of blast furnace slag fine powder, 10 to 20 wt% of F grade fly ash, 10 to 20 wt% of C grade fly ash having a calcium oxide content of 20% To 5% by weight of pulp slurry and 10 to 20% by weight of paper ash sludge incineration ash.

Korean Patent Registration No. 2016-1631467 discloses that a blast furnace slag powder having a specific surface area of 3,500 to 8,000 cm ² / g is mixed with 100 parts by weight of a blast furnace slag powder having a calcium oxide content of 50 to 80% by weight and a sulfate oxide 1 to 200 parts by weight of a desulfurization by-product produced in the combustion of petro coke having a specific surface area of 10 to 40% by weight and a specific surface area of 2,000 to 8,000 cm ² / g, and 5 to 200 parts by weight of cement is mixed with liquid sodium silicate The present invention provides a grouting chemical solution manufacturing method for injecting a grouting solution.

These techniques are based on the theory of an alkali activated slag which activates the blast furnace slag fine powder by alkali and sulphate stimulation caused by gypsum generated as a byproduct of the desulfurization process which occurs during the combustion of Petro coke and uses a high calcium incineration as an expansion material Content. That is, the above-mentioned patents can be regarded as a technique for early stabilizing the ground by utilizing the strength development of the alkali activated slag and the expandability of the high calcium incineration ash.

However, some of the above technologies have not been commercialized due to the complexity of the manufacturing process and the cost of expensive raw materials such as the use of expensive drugs as sulfite stimulants.

Korean Patent No. 10-0699430 Korean Patent No. 10-0886220 Korean Patent No. 10-0834923 Korean Patent No. 10-0804807 Korean Patent No. 10-1402877 Korean Patent Application No. 10-1631467

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide a cement mortar composition for a cement mortar for slabs, Which is a byproduct of desulfurization process of a steel mill, as a combined stimulant of alkali and sulfate, and a natural mineral powder as a filler, and a ground reinforcement method using the same.

In order to solve the above-mentioned technical problem, the groundfill material according to the present invention is characterized in that it comprises an in-furnace desulfurization-type circulating fluidized bed boiler having a CaO content of 15 to 70% by weight and an SO ₃ content of 3 to 30% 0.5 to 500 parts by weight of a high calcium soft material, 0.1 to 100 parts by weight of a manganese oxide produced as a by-product in a steel desulfurization process having an Na ₂ O content of 10 to 50% by weight and an SO ₃ content of 10 to 50% 5 to 500 parts by weight of a natural mineral filler selected from the group consisting of fine limestone powder, feldspar fine powder, fine silica powder, granite fine powder and dolomite fine powder.

In order to improve fluidity and long-term strength, a pulverized coal boiler having an SiO ₂ content of 35 to 60 wt%, a CaO content of 0.5 to 10 wt% and an SO ₃ content of 0.1 to 3 wt% based on 100 wt% It is preferable to further include 0.5 to 500 fly ash.

In order to improve the flowability, it is preferable that 0.01 to 20 parts by weight of the liquid and powder type fluidizing agent is further added to 100 parts by weight of the blast furnace slag fine powder.

In order to prevent underwater separation, it is preferable to further include 0.01 to 20 parts by weight of a water-insoluble agent in 100 parts by weight of the blast furnace slag fine powder.

Further, it is preferable that 0.01 to 20 parts by weight of a foaming agent or a foaming agent is further added to 100 parts by weight of the blast furnace slag fine powder in order to form pores.

The method of reinforcing a ground according to the present invention comprises the steps of: 1) producing the groundfill material according to any one of claims 1 to 4; 2) mixing 50 to 300 parts by weight of water with respect to 100 parts by weight of the injection material to prepare a slurry; 3) injecting the slurry prepared above to fill the gap or mix with the gravel; And 4) curing the filled slurry and the mixed soil.

According to the present invention, it is possible to utilize the natural mineral fine powder as a filler, the high calcium burned material discharged from the circulating fluidized bed boiler, and the gypsum as a by-product of the steel desulfurization process as a stimulant for the blast furnace slag fine powder.

As a result, hydration reaction and activity of blast furnace slag fine powder are promoted, thereby being able to replace one kind of ordinary cement which is most widely used in soft ground reinforcement work.

Further, it is possible to provide a non-toxic groundfill material free from alkali leaching and heavy metal leaching.

Hereinafter, an eco-friendly ground filler material free from heavy metal leaching according to the present invention and a ground reinforcement method using the same will be described in detail.

The eco-friendly groundfill material according to the present invention is characterized by comprising 0.5 to 500 parts by weight of a high-calorific burned material of an in-furnace desulfurization type circulating fluidized bed boiler, 10 to 50% by weight of Na ₂ O and 10 to 50% by weight of SO _3, 0.1 to 100 parts by weight of manganese produced as a by-product in a steel-making desulfurization step of a steelmaking process and a natural mineral or a mixture of two or more selected from the group consisting of limestone fine powder, feldspar fine powder, fine silica powder, granite fine powder and dolomite fine powder, 5 to 500 parts by weight of a filler.

The blast furnace slag is a by-product obtained by quenching slag in a high-temperature molten state generated as a by-product in a steelmaking blast furnace process with water. The blast furnace slag fine powder is called a latent hydraulic material because the amorphous coating is formed when it comes into contact with water and the hydration reaction does not occur by itself. The amorphous film must be destroyed in order for the latent hydraulic properties to be exhibited. The blast furnace slag fine powder can be used if it is a commercially available product having a specific surface area of 3,000 cm ² / g or more.

The in-furnace desulfurization circulating fluidized-bed boiler The high-calcium combustible material is generated in a boiler of a circulating fluidized bed boiler using coal or petroleum coke as its main fuel, in a furnace in which the furnace is desulphurized in a furnace together with limestone. In the desulfurization process of the circulating fluidized bed boiler, limestone is injected into the combustion chamber and burned together with the fuel, so that sulfur oxide and limestone in the combustion gas react in the furnace to remove sulfur in the combustion gas and produce anhydrous gypsum. It is carbonated and transferred to the quicklime component and discharged. Therefore, it can be said that it is a strong alkali substance having a pH of 12.0 or more and has an excellent composition as a stimulant for blast furnace slag fine powder.

When water is added to ordinary blast furnace slag fine powder, an amorphous film is formed on the surface, and the internal Ca ^{2 +} , Al ^{3 +,} etc. are not eluted. However, when the water is introduced after mixing the high calcium carbonate with the circulating fluidized bed boiler, the CaO component contained in the high calcium combustor reacts with water to convert it into Ca (OH) ₂ , resulting in OH ^- and SO ₄ ^2- component destroys the amorphous coating film of the blast furnace slag fine powder to facilitate the elution of Ca ^{2 +} , Al ^{3 +,} etc., and the elution ions generate CaO-SiO ₂ -H ₂ O based hydrate, It is possible to improve the compressive strength of the cured body.

The in-furnace desulfurization type circulating fluidized bed boiler high calcium soft material preferably has a CaO content of 15 to 70% by weight. If it is less than 15% by weight, the content of CaO existing in the form of pure CaO itself is insufficient, except for about 10% by weight of CaO present in the form of CaCO ₃ and CaSO ₄ . That is, since the pure CaO reacts with water and is converted into Ca (OH) ₂ and the amount of OH ^- ion generated is insufficient, the amorphous film of the blast furnace slag fine powder is difficult to break down in a short period of time. In addition, the pure CaO present in the high-calcium soft material reacts with water and absorbs, exotherms and expands to form Ca (OH) _2. The reaction equation is as follows.

CaO + H ₂ O-> Ca (OH) ₂ + 15.6 kcal mol ^-1

Therefore, the pure CaO component reacts with water to convert it to calcium hydroxide, and also acts as an alkali stimulant of fine powdered slag powder. However, the temperature elevation due to exothermic heat also promotes potential hydration and compensates for volumetric shrinkage of the cured body. If the CaO content is more than 70% by weight, the CaO content existing in the pure CaO form may be excessively absorbed, excessively absorbing the moisture, excess heat generation and expansion may occur, and cracks may be caused. Therefore, it is necessary to perform chemical quantitative analysis before the raw materials in the circulating fluidized bed boiler high calcium smelting material to use CaO content of 15 ~ 70% by weight. The SO ₃ content of the high calcium soft material is preferably 3 to 30% by weight. If the amount is less than 3% by weight, the SO ₃ content which can stimulate the blast furnace slag is insufficient and the strength is difficult to manifest. If the blending amount exceeds 30%, the excessive amount of SO ₃ is not reacted with the slag, . It is preferable to analyze the chemical composition and use a high calcium soft material within the above range.

It is preferable that the high calcium soft material is mixed in an amount of 0.5 to 500 parts by weight based on 100 parts by weight of the blast furnace slag fine powder. If the amount is less than 0.5 part by weight, the effect is not exhibited. If the amount is more than 500 parts by weight, And the intensity of the stimulant is greatly decreased due to excessive stimulant.

The gangcho is a by-product in the desulfurization process for removing sulfur dioxide (SO ₂ ) in the steel industry, and the gangue (Na ₂ SO ₄ ) containing a large amount of impurities is generated, reaching 40,000 tons / year. In the case of pulverulent mangroves produced in the steelmaking process, since there are many impurities, proper use is not found. In the present invention, blast furnace slag and pulverized coal boiler fly ash using an alkaline and sulphate complex irritant, and wastes generated from wastes in a steel mill have been used as a part of increasing the strength of the ground injection material using the blast furnace slag and pulverized coal boiler fly ash. In addition, the gum can be dissolved well in water to greatly increase the fluidity of the injection material.

The content of Na ₂ O is preferably 10 to 50% by weight. If it is less than 10% by weight of granulated blast furnace does not lack the stimulating effect of the slag and a pulverized coal fly ash and expressing the strength contain the other impurities is excessive contrast, if the Na ₂ O content exceeds 50% by weight is the relatively SO ₃ content is reduced The sulfate stimulating effect is reduced and the Na ₂ O component is eluted, resulting in whitening. The SO ₃ content is preferably 10 to 50% by weight, and if it is less than 10% by weight, the SO ₃ content capable of stimulating the blast furnace slag is insufficient and the strength development is difficult. When the content exceeds 50% SO ₃ content is present and the strength may be lowered. Therefore, it is preferable that the gypsum generated as a by-product of the steel smelting desulfurization step is subjected to a chemical quantitative analysis before the raw material supply so that the gypsum having an Na ₂ O content of 10 to 50 wt% and an SO ₃ content of 10 to 50 wt% is preferably used.

When the amount of the blast furnace slag powder is less than 0.1 parts by weight, the effect is not exhibited. When the blast furnace slag powder is more than 100 parts by weight, the blast furnace slag fine powder and the fine powder The amount of boiler fly ash is relatively decreased, and the potential hydraulic property is lowered, and the excess amount of the fly ash is present, and the strength is greatly lowered.

It is preferable that the natural mineral filler is any one or a mixture of two or more selected from among a limestone fine powder, a feldspar fine powder, a fine silica powder, a granite fine powder and a dolomite fine powder pulverized to particle size of 50 탆 or less in order to fill micropores in the injection material and reduce toxicity. If the amount of the natural mineral filler is less than 5 parts by weight, the filler effect and toxicity reduction effect can not be exhibited. If the amount of the filler is more than 500 parts by weight, do.

In order to improve the fluidity and long-term strength, it further includes 0.5 to 500 pulverized coal boiler fly ash having an SiO ₂ content of 35 to 60 wt%, a CaO content of 0.5 to 10 wt% and an SO ₃ content of 0.1 to 3 wt% .

The pulverized coal-fired boiler fly ash is collected when a combustion gas of a pulverized coal combustion boiler passes through a dust collecting apparatus in a thermal power plant having a separate desulfurization facility. Since the CaO content is less than 10% by weight, Of neutral and low alkali materials.

The coal-fired boiler fly ash of the thermal power plant is partially substituted for Portland cement. Since fly ash has a spherical shape, its fluidity increases and pozzolan reactivity increases. In the early ages, however, its hardening property is weak Do. That is, when mixed with Portland cement, fly ash is stimulated and hardened after the hydration product of cement, i.e., calcium hydroxide, is produced. As a result, the reaction of fly ash starts secondarily. For this reason, when fly ash is mixed with Portland cement, problems such as delayed coagulation, initial strength reduction, and neutralization are caused. Due to such a phenomenon, there may arise problems such as delays in form deformation, deterioration in initial strength, and deterioration in long-term durability due to neutralization at the construction site, and the content of fly ash relative to 100 wt% of Portland cement is used as 5 to 20 wt% . In the present invention, the CaO component of the circulating fluidized bed boiler high-calcium burned material reacts with water to form Ca (OH) ₂ And the pozzolanic reaction of pulverized coal boiler fly ash is initially activated by the stimulating effect of NaOH produced by the reaction of the Na ₂ O component of the moss with water.

The pulverized coal boiler fly ash is preferably blended in an amount of 0.5 to 500 parts by weight based on 100 parts by weight of the blast furnace slag fine powder. If the blast furnace fly ash is less than 0.5 part by weight, the effect is not exhibited. If the blending amount is more than 500 parts by weight, Of the fly ash is present in a large amount.

Further, it is preferable to further include liquid and powder type fluidizing agents in order to improve fluidity. The fluidizing agent is preferably one selected from the group consisting of naphthalene type, melamine type, amine type, lignin type and polycarboxylic type, or a mixture of two or more thereof. When the amount of the fluidizing agent is less than 0.01 part by weight, the fluidity is not improved. When the amount of the fluidizing agent is more than 20 parts by weight, the fluidity is excessively improved and the material separation may occur It is not economical.

In addition, it is preferable to further include an in-water insolubilizing agent to prevent underwater separation. The water-in-oil separating agent is selected from the group consisting of HYDROXY PROPYL METHYL CELLULOSE (HPMC), HYDROXY ETHYL CELLULOSE, HEC, CARBOXY METHYL CELLULOSE, CMC, ETHYL HYDROXY ETHYL CELLULOSE, EHEC), POLYACRYL SALT, POLY SACCARIDE, HYDROXY ETHYL METHYL CELLULOSE, HEMC, POLY ETHYLENE OXIDE, PEO, ETHYLENE VINYL ACETATE, EVA), or a mixture of two or more thereof. It is preferable that the above-mentioned underwater dispersing agent is incorporated in an amount of 0.1 to 20 parts by weight based on 100 parts by weight of the blast furnace slag. If the amount is less than 0.01 parts by weight, It becomes difficult.

Further, it is preferable to further include a foaming agent or a foaming agent in order to form pores. A foaming agent and a foaming agent are further added to minimize the load on the lower structure by replacing the volume of the fine aggregate and the coarse aggregate while reducing the weight. The foaming agent is a foaming agent used in concrete, and foaming agents such as animal and vegetable foaming agents and aluminum powders commonly used in Korea can be used. The foaming agent and the foaming agent are preferably incorporated in an amount of 0.01 to 20 parts by weight based on 100 parts by weight of the blast furnace slag. When the blending amount is less than 0.01 parts by weight, the pore generating effect is not exhibited. When the blending amount is more than 20 parts by weight, It is not economical.

Hereinafter, a ground reinforcement method according to the present invention will be described.

The ground reinforcement method comprises the steps of: 1) manufacturing the injection material; 2) mixing 50 to 300 parts by weight of water with respect to 100 parts by weight of the injection material to prepare a slurry; 3) injecting the slurry to fill the gap or mix with the gypsum; 4) curing the filled slurry and the mixed soil. The slurry discharged in the step 3) should be maintained so that a certain amount of the slurry is normally sprayed, and a bulb should be formed at the tip of the slurry, or a site requiring infiltration to the microvoids should be consolidated at a high pressure and injected, If the site is filled with voids, it is preferable to inject it at low pressure. In case of mixing with slurry and on-site soil, the rotational speed of the ogre should be adjusted according to the N value of the soil so that homogeneous mixing can be achieved. It is preferable to give a rotation time of at least 1 minute.

In the step 4), it is preferable to perform the room-temperature curing or the heat-curing at a sufficiently high temperature before curing is sufficiently performed.

Hereinafter, preferred embodiments and comparative examples of the present invention will be described. The following examples are intended to illustrate the invention and should not be construed as limiting the scope of the invention.

Comparative Example

100 parts by weight of water was added to 100 parts by weight of the first kind of cement, followed by wet mixing to prepare a homogeneous slurry mixture. Nine specimens of Ø10 cm × 20 cm were prepared and cured at 20 ° C., and the strengths were measured at 3 days, 7 days and 28 days.

Example

50 parts by weight of a high calorific burned material in a petroleum coke combustion furnace in a petroleum coke combustion furnace having a CaO content of 58.9% by weight and an SO ₃ content of 25.8% by weight based on 100 parts by weight of a blast furnace slag fine powder having a specific surface area of 4,360 cm ² / 30 parts by weight of manganese oxide produced as a by-product in a steel desulfurization process having a ₂ O content of 43.9% by weight and an SO ₃ content of 43.9% by weight and 20 parts by weight of a limestone fine powder having an average particle diameter of 13 μm were charged and dry mixed. 100 parts by weight of water was further added to 100 parts by weight of the mixture, followed by wet mixing to prepare a homogeneous slurry mixture. Nine specimens of Ø10 cm × 20 cm were prepared and cured at 20 ° C., and the strengths were measured at 3 days, 7 days and 28 days.

Test methods and results of specimens

As shown in Table 1 below, the compressive strength test was carried out by the uniaxial compressive strength test method of KS F 2343. The pH and heavy metal leaching test were carried out by collecting a part after 28 days compressive strength measurement.

Experiment Way Remarks Compressive strength KS F 2343 Uniaxial Compressive Strength Test Method Heavy metal leaching Waste process test standard Heavy metal dissolution test method pH Waste process test standard

(One) Uniaxial compressive strength  change

Table 2 below shows the uniaxial compressive strengths of Comparative Examples and Examples. As can be seen from the above, the example using the blast furnace slag fine powder, the circulating fluidized bed boiler high calcium soft material, the steel by-product desulfurization process by-product, and the natural mineral filler, compared with Comparative Example 1 using the first grade cement, Was slightly lower than that of long - term aged 90 days. Thus, it can be seen that the groundfill material of the present invention can replace the first-class cement used in the ground reinforcement method.

division Compressive strength 7 days
(MPa) Compressive strength 28 days
(MPa) Compressive strength 90 days
(MPa) Comparative Example 10.56 21.20 24.20 Example 8.78 18.64 25.43

(3) Extraction of heavy metals

pH KSLT Hexavalent chromium Copper Mercury cadmium lead arsenic Acceptance criteria 12.5 1.5 3.0 0.005 0.3 3.0 1.5 Comparative Example 12.6 0.783 0.745 Non-detection 0.351 0.258 0.077 Example 11.8 Non-detection Non-detection Non-detection Non-detection Non-detection Non-detection

The results of the pH and heavy metal leaching test results in Table 3 show that the pH of the comparative example is higher than the waste allowable reference value of 12.5, but in the case of the embodiment, it is 11.8, which is within the allowable standard. Therefore, when cement is used, the possibility of contamination of the soil due to leaching of the strong alkali component is high.

 The elution of heavy metals was found to be acceptable in the comparative example, but in the case of hexavalent chromium, the amount exceeding 50% of the standard value was eluted. All of the examples of the present invention, however, did not detect any heavy metals as well as hexavalent chromium.

 Therefore, the groundfill material of the present invention and the ground reinforcement method using the same are used as a stimulant of the granulated blast furnace slag powder in the circulating fluidized bed boiler and the desulfurization process of the steel mill to produce the strength and to use the natural mineral filler It is possible to substitute or minimize the amount of one kind of ordinary cement which is widely used. In addition, it is an eco-friendly ground filler that can reduce production cost by reducing cement usage, natural resource and energy depletion problem, carbon dioxide emission, strong alkali leaching and environmental pollution problem by leaching harmful heavy metal, and ground reinforcement method using it.

Claims (6)

With respect to 100 parts by weight of the blast furnace slag fine powder,
0.5 to 500 parts by weight of an in-furnace desulfurization-type circulating fluidized-bed boiler high-calcium burned material having a CaO content of 15 to 70% by weight and an SO ₃ content of 3 to 30%
0.1 to 100 parts by weight of manganese oxide produced as a by-product in a steel desulfurization process having an Na ₂ O content of 10 to 50% by weight and an SO ₃ content of 10 to 50%
And 5 to 500 parts by weight of a natural mineral filler selected from the group consisting of limestone fine powder, feldspar fine powder, fine silica powder, fine granite fine powder and dolomite fine powder having a particle diameter of 50 μm or less.
The method according to claim 1,
In order to improve the fluidity and the long-term strength, with respect to 100 parts by weight of the blast furnace slag fine powder,
Coal boiler fly ash having an SiO ₂ content of 35 to 60% by weight, a CaO content of 0.5 to 10% by weight and an SO ₃ content of 0.1 to 3% by weight.
The method according to claim 1,
In order to improve the flowability, with respect to 100 parts by weight of the blast furnace slag fine powder,
The non-toxic ground filler material according to claim 1, further comprising 0.01 to 20 parts by weight of a liquid and powder type fluidizing agent.
The method according to claim 1,
In order to prevent water separation, 100 parts by weight of the blast furnace slag fine powder,
Further comprising 0.01 to 20 parts by weight of an underwater dispersing agent.
The method according to claim 1,
To 100 parts by weight of the blast furnace slag fine powder to form pores,
Characterized in that it further comprises 0.01 to 20 parts by weight of a foaming agent or foaming agent.
1) producing the ground filler according to any one of claims 1 to 4;
2) mixing 50 to 300 parts by weight of water with respect to 100 parts by weight of the injection material to prepare a slurry;
3) injecting the slurry prepared above to fill the gap or mix with the gravel; And
4) curing the filled slurry and the mixed soil.