KR102306318B1 - Solidifying agent composition for soft ground and manufacturing method thereof - Google Patents

Abstract

Disclosed is a solidifying agent composition for soft ground, comprising: 10 to 20 parts by weight of Portland cement having a specific surface area of 2,800 to 4,000 cm^2/g; 30 to 40 parts by weight of fine powder of blast furnace slag having a specific surface area of 3,500 to 5,000 cm^2/g; 20 to 30 parts by weight of an ash mixture in which fly ash and bottom ash are mixed in a weight ratio of 1: 0.3 to 1.5 and having a specific surface area of 3,500 to 4,500 cm^2/g; 10 to 20 parts by weight of desulfurized gypsum; 5 to 10 parts by weight of recycled aggregate including fine aggregate and coarse aggregate; 5 to 10 parts by weight of waste inorganic acid selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, and a mixture of two or more thereof; and 5 to 10 parts by weight of one curing accelerator selected from the group consisting of sodium sulfate, calcium sulfate, and a mixture thereof. Accordingly, the strength of the soft ground can be improved.

Description

Solidifying agent composition for soft ground and manufacturing method thereof

The present invention relates to a solidifying agent composition for soft ground having excellent solidifying performance and a method for manufacturing the same.

In areas with high humidity, such as reclaimed or dredged landfills such as coastal wetlands, mud, rivers, lakes, and harbors, the ground is generally weak. and strengthen support. In order to solve this problem, in general, a hardening agent was used to harden the soft ground.

In general, a solidifying agent is an additive to solidify a liquid material, and is used to solidify soft ground or sludge. Specifically, the solidifying agent reacts with the soft ground or sludge to form a physically and chemically stable hardening body, thereby strengthening the ground, solidifying the hazardous waste, and preventing the leaching of heavy metals, etc. It can play a role in preventing contamination.

Conventionally, cement or solidifying agents, mainly made of ash, have been widely used, but since cement is manufactured by calcining at a high temperature, economical costs are increased, and since heavy metals such as hexavalent chromium remain, time elapses after solidification treatment Accordingly, there is a problem in that heavy metals are eluted from the cement and contaminate the surrounding soil or groundwater. In addition, since lime changes the soil to a strong alkalinity, there is a problem that inhibits the growth of plants.

On the other hand, in the case of a soil having a high water content and a large amount of organic matter or heavy metal compound, cement is rapidly combined with calcium divalent ions in the liquid phase during hydration to form lime salt that does not contribute to solidification, and the lime salt is By densely coating the surface of the cement particles to delay or stop the hydration reaction, solidification inhibition occurs. When such a solidification inhibition phenomenon occurs, it becomes difficult to express the desired strength even if a large amount of cement is used. For this reason, the hardening agent for soft ground hardens the soft ground, does not elute the hexavalent chromium contained in the cement, and solidifies the cement even in the case of a soil with a high water content and a large amount of organic matter or heavy metal compound. Inhibition should be suppressed.

Conventional solidifying agents for soft ground include cement mixed with slag and anhydrite, cement with fly ash and anhydrite, or cement with CSA-based mixture. has been However, the solidifying agent mixed with the CSA-based admixture with cement has the advantage of improving workability and constructability as the time required for coagulation is shorter than that of other mixtures. . In addition, there is a problem in that it is used as a solidifying agent for the ground due to a large shrinkage phenomenon, and there is a problem in that the effect of fixing the heavy metal contained in the cement is weak so that it does not elute.

In order to solve this problem, various solidifying agents have been developed in the prior art, but most of them use cement as the main raw material and input a large amount, so hardening is slow, and heat of hydration is generated during solidification to cause volume change, resulting in cracks. It still exists.

Therefore, there is a demand for the development of a hardening agent composition for a soft ground that can improve the properties of the soil by preventing the elution of heavy metals and improving the solidification performance by early expression of the coagulation of the soft ground.

In order to solve the above-mentioned problems of the prior art, it is possible to improve the eco-friendliness by reducing the use of cement by mixing industrial by-products, and the hardening agent composition for soft ground having improved solidification performance and soil characteristics of the soft ground, and its composition To provide a manufacturing method.

According to one aspect, 10 to 20 parts by weight of Portland cement having a specific surface area of 2,800 to 4,000 cm2/g; 30-40 parts by weight of fine powder of blast furnace slag having a specific surface area of 3,500-5,000 cm2/g; Fly ash and bottom ash are mixed in a weight ratio of 1: 0.3 to 1.5, and 20 to 30 parts by weight of an ash mixture having a specific surface area of 3,500 to 4,500 cm 2 / g; 10-20 parts by weight of desulfurized gypsum; 5-10 parts by weight of recycled aggregate including fine aggregate and coarse aggregate; 5-10 parts by weight of a spent inorganic acid selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, and a mixture of two or more thereof; and 5 to 10 parts by weight of one hardening accelerator selected from the group consisting of sodium sulfate, calcium sulfate, and mixtures thereof.

In one embodiment, the ash mixture may include fly ash and bottom ash generated in coal-fired power plants and cogeneration plants using coal as fuel.

In one embodiment, the desulfurized gypsum may be generated in the exhaust gas desulfurization process of a pressurized fluidized bed boiler.

In one embodiment, the average particle diameter of the recycled aggregate may be 0.05 ~ 5mm.

In one embodiment, the spent inorganic acid may be solidified by further including calcium oxide.

In one embodiment, the water content of the solidified waste inorganic acid may be 10% or less.

According to another aspect, (a) 10 to 20 parts by weight of Portland cement having a specific surface area of 2,800 to 4,000 cm / g, 30 to 40 parts by weight of fine powder of blast furnace slag having a specific surface area of 3,500 to 5,000 cm / g, fly ash and Bottom ash is mixed in a weight ratio of 1: 0.3 to 1.5, and 20 to 30 parts by weight of an ash mixture having a specific surface area of 3,500 to 4,500 cm2/g, 10 to 20 parts by weight of desulfurized gypsum, 5 to recycled aggregate containing fine aggregate and coarse aggregate mixing 10 parts by weight; (b) mixing 5 to 10 parts by weight of a spent inorganic acid selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid and a mixture of two or more thereof in the mixture of (a); (c) mixing 5 to 10 parts by weight of one hardening accelerator selected from the group consisting of sodium sulfate, calcium sulfate, and mixtures thereof with the mixture of (b); do.

In one embodiment, the step (b) comprises: i) mixing the spent inorganic acid and calcium oxide in a weight ratio of 60 to 80: 20 to 40; ii) drying the mixture of i) at 400 to 600° C. for 0.5 to 2 hours to solidify; And iii) pulverizing the solid material to 50 ~ 300㎛; may include.

In one embodiment, the water content of the solidified waste inorganic acid may be 10% or less.

In one embodiment, the mixing in steps (a) to (c) may be performed using one or more stirrers having a rotation speed of 300 to 500 rpm.

According to one aspect, the solidifying agent composition for soft ground and its manufacturing method include industrial by-products such as blast furnace slag fine powder, ash mixture, desulfurized gypsum, and recycled aggregate in cement, compared to the conventional solidifying agent composition, which is environmentally friendly by reducing the use of cement. performance and economic efficiency can be improved. In addition, by adding the spent inorganic acid and hardening accelerator, it is possible to accelerate the solidification of the soft ground to express early strength, thereby improving the strength of the soft ground.

The effect of one aspect of the present specification is not limited to the above-described effect, but it should be understood to include all effects that can be inferred from the configuration described in the detailed description or claims of the present specification.

1 is a schematic view of a method of manufacturing a solidifying agent composition for soft ground according to an embodiment of the present specification.

Hereinafter, one aspect of the present specification will be described with reference to the accompanying drawings. However, the description of the present specification may be implemented in several different forms, and thus is not limited to the embodiments described herein. And in order to clearly explain one aspect of the present specification in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part is "connected" with another part, this includes not only the case where it is "directly connected" but also the case where it is "indirectly connected" with another member interposed therebetween. . In addition, when a part "includes" a certain component, this means that other components may be further provided without excluding other components unless otherwise stated.

When a range of numerical values is recited herein, the values have the precision of the significant figures provided in accordance with the standard rules in chemistry for significant figures, unless the specific range is otherwise stated. For example, 10 includes the range of 5.0 to 14.9 and the number 10.0 includes the range of 9.50 to 10.49.

Solidifying composition for soft ground

According to one aspect, 10 to 20 parts by weight of Portland cement having a specific surface area of 2,800 to 4,000 cm 2 /g; 30-40 parts by weight of fine powder of blast furnace slag having a specific surface area of 3,500-5,000 cm2/g; Fly ash and bottom ash are mixed in a weight ratio of 1: 0.3 to 1.5, and 20 to 30 parts by weight of an ash mixture having a specific surface area of 3,500 to 4,500 cm 2 / g; 10-20 parts by weight of desulfurized gypsum; 5-10 parts by weight of recycled aggregate including fine aggregate and coarse aggregate; 5-10 parts by weight of a spent inorganic acid selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, and a mixture of two or more thereof; and 5 to 10 parts by weight of one hardening accelerator selected from the group consisting of sodium sulfate, calcium sulfate, and mixtures thereof.

The total weight of the solidifying agent composition for soft ground may be 100 parts by weight, but is not limited thereto.

Conventional hardener compositions have been used including cement as a main raw material, but economic feasibility is reduced due to high unit price, and in the case of soil containing high water content and high organic matter or heavy metal compounds, calcium divalent ions in the liquid phase are combined during cement hydration process. As a result, lime salt that does not contribute to solidification may be generated, and thus there may be a problem of lowering the solidification performance of cement. In addition, since there is a risk of elution of hexavalent chromium contained in cement, an alternative material capable of minimizing the addition of cement is required.

Accordingly, the solidifying agent composition according to one aspect may include 10 to 20 parts by weight of Portland cement having a specific surface area of 2,800 to 4,000 cm 2 /g. The content of the Portland cement is, for example, 10 parts by weight, 11 parts by weight, 12 parts by weight, 13 parts by weight, 14 parts by weight, 15 parts by weight, 16 parts by weight, 17 parts by weight, 18 parts by weight, 19 parts by weight or It may be 20 parts by weight, but is not limited thereto. The Portland cement can serve to produce calcium hydroxide by hydration reaction with water while using less compared to the conventional solidifying agent composition, and can be induced to act as an alkali stimulant for the fine powder of blast furnace slag due to the production of calcium hydroxide. have.

The solidifying agent composition may contain 30 to 40 parts by weight of fine blast furnace slag powder having a specific surface area of 3,500 to 5,000 cm2/g, for example, 30 parts by weight, 31 parts by weight, 32 parts by weight, 33 parts by weight, 34 parts by weight. parts, 35 parts by weight, 36 parts by weight, 37 parts by weight, 38 parts by weight, 39 parts by weight or 40 parts by weight, but is not limited thereto, and if the content is less than 30 parts by weight, the solidification performance may be lowered, If it exceeds 40 parts by weight, it may be included more than necessary, and other physical properties may be reduced. The fine powder of blast furnace slag can be prepared by drying and pulverizing crushed blast furnace slag treated by quenching high-temperature molten blast furnace slag generated as a by-product in the ironmaking process with water, and by quenching it to vitrify it, thereby improving reactivity. The blast furnace slag fine powder may have a basicity of 1.5 to 2.0, for example, 1.5, 1.6, 1.7, 1.8, 1.9 or 2.0, but is not limited thereto.

In addition, the fine blast furnace slag powder may _{include one selected from the group consisting of silica (SiO 2} ), aluminum oxide (Al ₂ O ₃ ), calcium oxide (CaO), magnesium oxide (MgO), and a mixture of two or more thereof. , but is not limited thereto. The fine powder of blast furnace slag has a chemical composition similar to that of cement and has a gentle initial strength expression, but has excellent watertightness, so it is possible to improve the interfacial properties of the soil particles and the bonding force between the particles, thereby inhibiting the elution of harmful substances. and can improve long-term strength due to latent hydraulic properties.

On the other hand, the solidifying agent composition may include 20 to 30 parts by weight of an ash mixture in which fly ash and bottom ash are mixed in a weight ratio of 1: 0.3 to 1.5 and a specific surface area of 3,500 to 4,500 cm 2 / g, for example, 20 It may be, but not limited to, parts by weight, 21 parts by weight, 22 parts by weight, 23 parts by weight, 24 parts by weight, 25 parts by weight, 26 parts by weight, 27 parts by weight, 28 parts by weight, 29 parts by weight, or 30 parts by weight. . The ash mixture may include fly ash and bottom ash generated in coal-fired power plants and cogeneration plants using coal as fuel. In detail, the ash mixture is fly ash and bottom ash generated when pulverized coal is burned at a high temperature of about 1,400 to 1,500 ° C in coal-fired power plants and cogeneration plants, and is very collected in an electric dust collector. It is fly ash in a fine powder state, and the bottom ash may be the bottom ash of the coarse powder that is not collected by the electric dust collector and is collected in the boiler combustion chamber or the lower part of the economizer and the air preheater.

The hardener composition may include 10 to 20 parts by weight of desulfurized gypsum, for example, 10 parts by weight, 11 parts by weight, 12 parts by weight, 13 parts by weight, 14 parts by weight, 15 parts by weight, 16 parts by weight, 17 parts by weight. The content may be, but not limited to, 18 parts by weight, 18 parts by weight, 19 parts by weight, or 20 parts by weight. . The desulfurized gypsum may be generated in the exhaust gas desulfurization process of a pressurized fluidized bed boiler, and in detail, the desulfurized gypsum may have a calcium oxide content of 50% or more, and a sulfur oxide content of 15 wt% or more. Accordingly, the desulfurized gypsum may serve as an initial moisture dehydration and strong alkali stimulant.

The solidifying agent composition may contain 5 to 10 parts by weight of recycled aggregate including fine aggregate and coarse aggregate, for example, 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight or 10 parts by weight. It may be a part by weight, but is not limited thereto. The recycled aggregate is an aggregate obtained by crushing construction waste such as waste concrete or asphalt, and the average particle diameter of the recycled aggregate may be 0.05-5 mm, and the coarse aggregate is 4.76 mm or more, 0.05 mm or more, 4.76 mm Those with less than the range are called fine aggregates. Since the recycled aggregate contains a large amount of lime component, it is possible to produce a solid material by a pozzolan reaction with components such as silica and alumina contained in the blast furnace slag or ash mixture, thereby strengthening the soft ground. As used herein, the term "pozzolan reaction" refers to a material that does not have the property of curing by reacting with water alone, but curing by reacting with lime (CaO) in water.

The solidifying agent composition may include 5 to 10 parts by weight of a spent inorganic acid selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, and a mixture of two or more thereof, for example, 5 parts by weight, 6 parts by weight, 7 parts by weight. , 8 parts by weight, 9 parts by weight or 10 parts by weight, but is not limited thereto.

In general, waste inorganic acid is a liquid, strong acid by-product containing a large amount of harmful substances generated during product processing in the overall industry, such as electronics, plating, and steel industry. , most of the waste inorganic acids are discharged through complex treatment processes such as neutralization, coagulation, precipitation, filtration, and dehydration, and among them, waste nitric acid and waste phosphoric acid are all heated with heat and evaporated into the atmosphere for treatment. However, the discharge of such waste inorganic acid deteriorates the water quality environment, and the fuel is used in the evaporation treatment by heating with heat, resulting in expensive treatment costs.

Accordingly, the spent inorganic acid may serve to neutralize the alkalinity of the soil by alkali components such as cement and blast furnace slag included in the solidifying agent composition. In general, when the pH of the soil is 8.5 or higher, it is called alkaline soil and may inhibit the growth of plants. Since the waste inorganic acid contains a large amount of high-concentration acid, the soil quality can be improved by suppressing alkalinization of the soil to which the solidifying agent composition is applied by being included in the solidifying agent composition.

Meanwhile, the spent inorganic acid may be solidified by further including calcium oxide. Since the waste inorganic acid contains a large amount of high-concentration acid, its physical properties may be reduced due to instantaneous exotherm and chemical reaction when mixed in a liquid phase. Accordingly, calcium oxide may be mixed with the spent inorganic acid to stabilize the pH of the spent inorganic acid, and it may be dried and solidified. The water content of the solidified waste inorganic acid may be 10% or less, and the average particle diameter may be 50 ~ 300㎛. The spent inorganic acid is included in the solidifying agent composition in the form of a solid powder, and thus can serve to absorb and harden the soft ground, thereby improving the strength of the soft ground.

On the other hand, the hardening agent composition may include 5 to 10 parts by weight of one curing accelerator selected from the group consisting of sodium sulfate, calcium sulfate, and mixtures thereof, for example, 5 parts by weight, 6 parts by weight, 7 parts by weight, It may be 8 parts by weight, 9 parts by weight or 10 parts by weight, but is not limited thereto. When the hardening accelerator is applied to soil, in particular, a soft ground containing a large amount of moisture, a hydration reaction occurs, and thus the dehydration reaction proceeds, thereby promoting early strength development and hardening of the soil, and improving the hardening performance of the hardening agent composition can be improved

Method for preparing a solidifying composition for soft ground

1 is a schematic view of a method of manufacturing a solidifying composition for soft ground according to an embodiment.

Referring to FIG. 1, (a) 10-20 parts by weight of Portland cement having a specific surface area of 3,000 to 4,000 cm2/g, 30-40 parts by weight of fine powder of blast furnace slag having a specific surface area of 3,500 to 5,000 cm2/g, fly ash and bottom Ash is mixed in a ratio of 0.3 to 1.5 by weight, and 20 to 30 parts by weight of an ash mixture having a specific surface area of 3,500 to 4,500 cm2/g, 10 to 20 parts by weight of desulfurized gypsum, and 5 to 10 recycled aggregates containing fine aggregates and coarse aggregates mixing parts by weight; (b) mixing 5 to 10 parts by weight of a spent inorganic acid selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid and a mixture of two or more thereof in the mixture of (a); (c) mixing 5 to 10 parts by weight of one hardening accelerator selected from the group consisting of sodium sulfate, calcium sulfate, and mixtures thereof with the mixture of (b); do.

The total weight of the solidifying agent composition for soft ground may be 100 parts by weight, but is not limited thereto.

First, in step (a), 10 to 20 parts by weight of Portland cement having a specific surface area of 3,000 to 4,000 cm2/g, 30 to 40 parts by weight of fine blast furnace slag powder having a specific surface area of 3,500 to 5,000 cm2/g, fly ash and bottom ash 1: 20 to 30 parts by weight of an ash mixture having a specific surface area of 3,500 to 4,500 cm2/g mixed in a ratio of 0.3 to 1.5 by weight, 10 to 20 parts by weight of desulfurized gypsum, and 5 to 10 parts by weight of recycled aggregate including fine aggregate and coarse aggregate A mixture can be prepared by mixing.

The mixture of (a) may be mixed with 5 to 10 parts by weight of a spent inorganic acid selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid and a mixture of two or more thereof in step (b). The step (b) comprises the steps of: i) mixing the spent inorganic acid and calcium oxide in a weight ratio of 60 to 80: 20 to 40; ii) drying the mixture of i) at 400 to 600° C. for 0.5 to 2 hours to solidify; And iii) pulverizing the solid material to 50 ~ 300㎛; may include. The water content of the solidified waste inorganic acid may be 10% or less. When the moisture content of the spent inorganic acid exceeds 10%, the solidifying performance of the solidifying composition may be deteriorated.

Meanwhile, the mixing in steps (a) to (c) may be performed using one or more stirrers. Specifically, the steps (a) to (c) can be carried out by sequentially adding Portland cement, blast furnace slag fine powder, ash mixture, desulfurized gypsum, recycled aggregate, spent inorganic acid and hardening accelerator into a single stirrer, and if necessary , each step may be performed individually on three stirrers, two or more steps may be performed on a single stirrer, and the remaining one step may be performed on a separate stirrer.

The stirrer may be of a horizontal arrangement type or a vertical arrangement form, but is not limited thereto. The vertical arrangement can implement kneading by gravity compared to the horizontal arrangement form, and effective kneading can be achieved because a separate means for input, movement and discharge of the kneaded material can be excluded, and in some areas, it is forced in the opposite direction to gravity. Since it is possible to improve the stirring efficiency while moving the kneaded material and the like while repeating rising and falling, it is preferable to use a vertical arrangement.

In addition, the rotation speed of the stirrer may be 300 ~ 500rpm. The rotational speed of the stirrer means the rotational speed of the blades or screws provided in the stirrer, and if the rotational speed of the stirrer is less than 300rpm, the required level of kneading effect cannot be realized, and if it exceeds 500rpm, the drive motor, reduction device, etc. are excessive. By applying a load, the life of the stirrer can be shortened.

Hereinafter, embodiments of the present specification will be described in more detail. However, the following experimental results describe only representative experimental results among the above examples, and the scope and content of the present specification may not be construed as reduced or limited by the examples. Each effect of the various embodiments of the present specification not explicitly presented below will be specifically described in the corresponding section.

Example 1

15 parts by weight of Portland cement having a specific surface area of 3,500 cm2/g, 35 parts by weight of fine blast furnace slag powder having a specific surface area of 4,000 cm2/g, fly ash and bottom ash are mixed in a weight ratio of 1:1, and the specific surface area is 4,000 cm2/g 25 parts by weight of phosphorus ash mixture, 10 parts by weight of desulfurized gypsum, and 5 parts by weight of recycled aggregate in which fine aggregate and coarse aggregate were mixed in a 1:1.5 weight ratio were put into a stirrer and kneaded at 350 rpm to prepare a mixture.

5 parts by weight of phosphoric acid as a waste inorganic acid was added to the prepared mixture and kneaded again, and then 5 parts by weight of sodium sulfate as a curing accelerator was added to prepare a hardener composition for soft ground.

Example 2

As a waste inorganic acid, nitric acid and calcium oxide were mixed in a weight ratio of 80: 20, and the prepared mixture was dried in a drying furnace at 500° C. for 1 hour to solidify, and then pulverized to an average particle size of 100 μm. Lungs having a moisture content of 8% A hardening agent composition for soft ground was prepared in the same manner as in Example 1, except that 5 parts by weight of the inorganic acid powder was included.

Comparative Example 1

A solidifying agent composition prepared from conventional Portland cement (1 type) was used as Comparative Example 1.

Comparative Example 2

A solidifying agent composition prepared from conventional blast furnace slag cement (2 types) was used as Comparative Example 2.

Comparative Example 3

A hardening agent composition was prepared in the same manner as in Example 1, except that the curing accelerator was not included.

Comparative Example 4

A solidifying agent composition was prepared in the same manner as in Example 1, except that the spent inorganic acid was not included.

Comparative Example 5

A hardening agent composition was prepared in the same manner as in Example 2, except that the curing accelerator was not included.

Comparative Example 6

A solidifying agent composition was prepared in the same manner as in Example 2, except that the spent inorganic acid was not included.

Experimental Example 1: Evaluation of physical properties of solidifying composition 1

For the evaluation of the physical properties of the solidifying agent compositions prepared in Examples and Comparative Examples, 10 kg of the solidifying composition of Examples and Comparative Examples was mixed with 10 kg of viscous soil having a moisture content of 46% and a wet unit volume weight of 1.8 kg/㎥, respectively, and the solidification treatment was performed. The moisture content, temperature, and ammonia concentration of the solid product were measured, and the results are shown in Table 1.

division Moisture content (%) Ammonia Concentration (ppm) Soil pH Example 1 40.1 200 9.5 Example 2 37.9 150 9.1 Comparative Example 1 45 850 13.4 Comparative Example 2 45.4 1,000 12.8 Comparative Example 3 43.4 240 9.6 Comparative Example 4 42.8 220 11.4 Comparative Example 5 43.4 190 9.7 Comparative Example 6 39.1 200 11.2

Referring to Table 1, the water content of the solidified material solidified with the solidifying agent composition of Example 1 was 40.1%, and the water content of the solidified material of Example 2 was 37.9%, which was lower than that of the clay soil. Therefore, it can be predicted that the ground of the clay soil has become hard. In addition, the ammonia concentration of the solidified materials according to Examples 1 and 2 was 200 ppm or less, confirming that almost no odor was generated, and the pH value of the soil was 9 or less, confirming that it was an appropriate value for the growth of organisms. Accordingly, it can be expected that the solidified material solidified with the solidifying agent composition of Examples 1 and 2 will provide improved physical properties when applied as a softening agent for soft ground, a soil conditioner, and the like.

On the other hand, in the case of the conventional hardener composition (Comparative Examples 1 and 2), the moisture content is at a level similar to the value of the clay itself, and the pH value of the soil increases due to the high alkalinity of the cement itself, so it can be predicted that the growth of organisms will be difficult. In addition, when the curing accelerator is not included (Comparative Examples 3 and 5), it can be confirmed that the water content is increased compared to Example 1 and the solidification performance is lowered, and when the spent inorganic acid is not included (Comparative Examples 4 and 6), It can be predicted that the growth of organisms will be difficult due to the alkaline soil as the pH value of the soil rises.

Experimental Example 2: Evaluation of physical properties of solidifying composition 2

In order to confirm the solidifying performance of the solidifying agent compositions prepared in Examples and Comparative Examples, 10 kg of the solidifying composition of Examples and Comparative Examples was mixed with 10 kg of viscous soil having a moisture content of 46% and a wet unit volume weight of 1.8 kg/㎥, respectively, and solidified. The uniaxial compressive strength of the treated solid at 1, 3, 7, and 28 days was measured, and the results are shown in Table 2.

division Uniaxial compressive strength of soil (㎫) 1 day 3 days 7 days 28 days Example 1 1.5 3.1 3.8 4.4 Example 2 1.8 3.6 4.2 4.7 Comparative Example 1 1.4 2.4 2.8 3.2 Comparative Example 2 1.2 1.8 2.5 2.8 Comparative Example 3 0.8 1.0 2.2 2.9 Comparative Example 4 0.7 1.5 2.1 2.7 Comparative Example 5 0.9 1.2 2.6 3.1 Comparative Example 6 0.8 One 2.7 3.2

Referring to Table 2, the uniaxial compressive strength of the solidified material solidified with the solidifying agent composition of Example 1 was 1.5 MPa for 1 day, 3.1 MPa for 3 days, 3.8 MPa for 7 days, and 4.4 MPa. The uniaxial compressive strength of the solidified material solidified with the topical composition was 1.8 MPa for 1 day, 3.6 MPa for 3 days, 4.2 MPa for 7 days, and 4.7 MPa, confirming that the solidification performance was excellent. It can be seen that the topical composition significantly improved the strengthening and improvement of soft ground while improving eco-friendliness and economic feasibility by preparing a low cement-based composition by mixing industrial by-products with cement.

On the other hand, in the case of the conventional solidifying agent composition (Comparative Examples 1 and 2), the initial uniaxial compressive strength showed a slight difference compared to the Example, but the value of the uniaxial compressive strength according to the passage of time showed a significant difference, and finally compared to the Example It can be confirmed that the solidification performance is lowered by showing a low uniaxial compressive strength value, and when the curing accelerator is not included (Comparative Examples 3 and 5), the initial uniaxial compressive strength value is lowered, and thus it can be confirmed that the solidification performance is lowered, When the waste inorganic acid is not included (Comparative Examples 4 and 6), it can be confirmed that the water content of the solidified material is increased and the solidification performance is finally deteriorated.

The description of the present specification described above is for illustration, and those of ordinary skill in the art to which one aspect of the present specification belongs can easily transform it into other specific forms without changing the technical idea or essential features described in this specification. you will be able to understand Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a dispersed form, and likewise components described as distributed may be implemented in a combined form.

The scope of the present specification is indicated by the following claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present specification.

Claims (10)

delete delete delete delete delete delete (a) 10-20 parts by weight of Portland cement with a specific surface area of 2,800-4,000 cm2/g, 30-40 parts by weight of fine blast furnace slag powder with a specific surface area of 3,500-5,000 cm2/g, fly ash and bottom ash 1: 0.3- Mixing in a 1.5 weight ratio, 20 to 30 parts by weight of an ash mixture having a specific surface area of 3,500 to 4,500 cm / g, 10 to 20 parts by weight of desulfurized gypsum, 5 to 10 parts by weight of recycled aggregate including fine aggregate and coarse aggregate;
(b) mixing 5 to 10 parts by weight of the solidified waste inorganic acid in the mixture of (a);
(c) mixing 5 to 10 parts by weight of one curing accelerator selected from the group consisting of sodium sulfate, calcium sulfate, and mixtures thereof with the mixture of (b);
The solid waste inorganic acid of step (b) is i) mixed with a waste inorganic acid selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, and a mixture of two or more thereof and calcium oxide in a weight ratio of 60 to 80: 20 to 40 step; ii) drying the mixture of i) at 400 to 600° C. for 0.5 to 2 hours to solidify; And iii) pulverizing the solid material to 50 ~ 300㎛; Method of producing a hardener composition for soft ground comprising a. delete 8. The method of claim 7,
The method for producing a solidifying composition for a soft ground, wherein the water content of the solidified waste inorganic acid is 10% or less. 8. The method of claim 7,
A method of producing a solidifying agent composition for soft ground in which the mixing in the steps (a) to (c) is performed using one or more stirrers having a rotation speed of 300 to 500 rpm.

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