KR101331057B1 - Solidified agent to strengthen stratum - Google Patents

Abstract

The present invention relates to a solidified fire to reinforce the ground, and more specifically, using blast furnace slag as the main raw material and petroleum coke desulfurized gypsum as a stimulant to activate the latent hydraulic properties of the blast furnace slag to express high grain strength, The present invention relates to a ground reinforcement solid which stabilizes the soil by removing the pore water and reducing the moisture content by using the exothermic reaction and volume expansion of calcium oxide.
The ground reinforcement solid according to the present invention comprises 20 to 50 parts by weight of petrol coke desulfurized gypsum, based on 100 parts by weight of blast furnace slag fine powder.

Description

Soil Reinforcement for Ground Reinforcement {SOLIDIFIED AGENT TO STRENGTHEN STRATUM}

The present invention relates to a solidified fire to reinforce the ground, and more specifically, using blast furnace slag as the main raw material and petroleum coke desulfurized gypsum as a stimulant to activate the latent hydraulic properties of the blast furnace slag to express high grain strength, The present invention relates to a ground reinforcement solid which stabilizes the ground by removing the pore water and reducing the water content by using the exothermic reaction and the volume expansion action of the calcium oxide.

Generally, deep mixing method (SCW: Soil Cement Wall, DCM: Deep Cement Mixing, DSP: Deep Soil Mixing Pile, DSM: Deep Soil Mixing, etc.) to improve the ground such as soft ground Improve the ground by mixing solid fire. At this time, the solidified material has been generally used by mixing cement and bentonite.

Among the cements, bentonite is used for ordering purposes because of its shrinkage during hydration. Bentonite is a mineral that does not exist as a natural resource in Korea. It is an expensive material that depends on imports. There is a problem that the degree of ordering is greatly reduced.

In addition, in the case of cement, limestone, which is a main raw material, is manufactured by baking at a high temperature of 1,450 ° C, and thus, a large amount of CO ₂ gas, which is the main cause of greenhouse gases, is generated in the decarbonation process of limestone, which causes fatal harm to the atmospheric environment. In addition, cement is not preferable when used in soil because the pH is strong enough to reach 12 or more.

Recently, several techniques have been proposed to solve the problem of using such conventional cement as a fire. For example, in Korean Patent Registration No. 10-0845248, blast furnace slag cement is mixed with quicklime and anhydrous gypsum and then pulverized using a vibration mill for the purpose of improving the degree of powder, and a poly And 0.1 to 0.5% by weight of a carboxylic acid-based admixture are re-mixed. However, this method requires the process of re-pulverization using a huge device called a vibration mill after purchasing the first-produced product, and furthermore, a technique of mixing 0.1% to 0.5% by weight of the polycarboxylic acid admixture back into the ground product. However, there is no commercialization technology that can evenly mix 0.1-0.5% by weight of raw materials into the powder with the current technology, which is very costly and technically difficult to commercialize.

In addition, Korean Patent No. 10-0374122 discloses 5 to 40 parts by weight of gypsum, 5 to 30 parts by weight of lime and 20 to 200 parts by weight of two particle sizes (15 to 30 μm of the first component with respect to 100 parts by weight of cement). A technique comprising a pozzolanic material having a 60 parts by weight, 40-50 parts by weight of a second component having a thickness of 3 to 8 μm) and a surfactant was proposed. However, this method has the above-mentioned problems in that cement is the main raw material, and in particular, the question of whether it is possible to separate pozzolanic materials into particles of 15 to 30 µm and 3 to 8 µm as an existing technique is possible.

In addition, in Korean Patent Registration No. 10-0553732, 70-80 parts by weight of alumino-silicate-based industrial byproducts having an average particle diameter of 10-15, 10-25 parts by weight of gypsum-based byproducts having an average particle diameter of 20-30, and alkali byproducts 5-10 The solidified material containing the weight part was shown. However, this technique also explains in the structure and action of the invention that the average particle size of the alumino-silicate-based industrial by-product, which is the main raw material, is large and the particle size is adjusted by using a roller mill, a ball mill or a vibration mill.

In addition, in the case of Korean Patent Registration No. 10-0431797, blast furnace slag, gypsum, sodium hydroxide, aluminum sulfate, quicklime or calcareous lime, limestone, and non-firing cement manufacturing method for grinding again after mixing the crude economy. This technology is based on blast furnace slag and fly ash instead of cement. It is a technique of adding alkali stimulants and sulfate stimulants as various raw materials or blended raw materials to improve pozzolanic reaction and ettringite formation. Therefore, the manufacturing process is very complicated, and the pretreatment of the raw material is expensive, and there is a problem in that it is difficult to select a formulation according to the variation of the physical and chemical quality characteristics of the raw material because various raw materials must be used at the same time.

The present invention has been made to solve the above object, the object of the present invention is to use the blast furnace slag as a main raw material and to utilize the petroleum coke desulfurization gypsum as a stimulant to activate the latent hydraulic properties of the blast furnace slag to express high grain strength, The present invention provides a ground reinforcement solid which stabilizes the ground quickly by removing the pore water and reducing the water content by using the exothermic reaction and volume expansion of calcium oxide contained in the expanded material.

In order to solve the above technical problems, the ground reinforcing solidified material according to the present invention includes petroleum coke desulfurized gypsum 20 to 50 parts by weight based on 100 parts by weight of blast furnace slag fine powder.

In addition, in order to rapidly reduce the water content and to remove the pore water of the soil through volume expansion, it is preferable to further include an expansion material.

In addition, the expansion material is a high calcium fly ash, biomass incineration residue, paper sludge incineration residue, RDF (Refuse Derived Fuel) incineration residue, RPF (Infuse Plastic Fuel) incineration residue, converter slag dust, quicklime And it is preferably one or a mixture of two or more selected from the group consisting of light dolomite.

In addition, the expansion material is preferably calcium oxide (CaO) content of 20 to 70%.

In addition, the expansion material is preferably mixed 40 to 100 parts by weight based on 100 parts by weight of the blast furnace slag fine powder.

According to the present invention, blast furnace slag is used as a main raw material and petroleum coke desulfurization gypsum is used as a stimulant to activate latent hydraulic properties of blast furnace slag to express high grain strength, and the exothermic reaction and volumetric expansion action of calcium oxide contained in a large amount of expansion material. By removing the pore water in the soil and reducing the moisture content it has the effect of stabilizing the ground as soon as possible.

The solidified material according to the present invention can be used not only for the deep mixing method, but also in various ways for reinforcing the ground such as solidified material for the formation of loess roads.

EMBODIMENT OF THE INVENTION Hereinafter, the solidifying material composition for ground reinforcement which concerns on this invention is demonstrated concretely.

The ground reinforcement solid according to the present invention comprises 20 to 50 parts by weight of petroleum coke desulfurized gypsum, based on 100 parts by weight of blast furnace slag fine powder obtainable on the market.

The petroleum coke desulfurized gypsum is produced by reacting a sulfur component contained in the petroleum coke with a CaO component dehydrated at a high temperature in the process of mixing limestone for desulfurization in a furnace in a boiler using petroleum coke as a raw material. Particulate gypsum material such as dust, which is a strong alkali material with a pH above 11.5. When sulphate and high pH contained in the gypsum are applied to the stimulation of sulfate and alkali stimulation according to pH to the blast furnace slag fine powder, the fine blast furnace slag powder is activated to express a latent hydrophobic reaction to express high grain strength. The hydration reaction of the slag fine powder and the sulphate stimulant of petroleum coke desulfurized gypsum is initiated by the backbone of a large amount of ettringite at the early age and is produced by the C-S-H gel produced at the same time. In addition, the CSH gel surrounds Etringite. As the age elapses, the amount of the CSH gel continuously increases and the CSH gel tightly fills the pores of the cured paste, forming a dense network network structure with etringing, .

In addition, it is preferable that the solidified material further includes an expanded material replacing bentonite in order to rapidly reduce the water content of the solidified soil mixed in the soil and to remove the pore number of the soil through volume expansion.

In addition, the expansion material is any one selected from the group consisting of high calcium fly ash, biomass incineration residue, paper sludge incineration residue, RDF incineration residue, RPF incineration residue, converter slag dust, quicklime and light dolomite generated in a furnace desulfurization coal combustion boiler. Or a mixture of two or more.

In addition, the expansion material is preferably mixed 40 to 100 parts by weight based on 100 parts by weight of the blast furnace slag fine powder.

In addition, the high-calcium fly ash, biomass incineration residue, paper sludge incineration residue, RDF incineration residue, and RPF incineration residue, which are generated in the furnace desulfurization type coal combustion boiler, are mixed and combusted with limestone to remove sulfur components in fuel. The particulate matter produced by chemical reaction of sulfur component of fuel and CaO component of decarbonated limestone in the process. Calcium oxide contained in large amounts in these incineration residues reacts with water to be absorbed, exothermic and expands to become calcium hydroxide. The reaction formula is as follows.

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

Although the incineration residue is usually recycled as a concrete admixture, incineration residues containing a large amount of calcium oxide can not be used as a concrete admixture because of its absorption, exothermic and expansion characteristics.

Therefore, the present invention generally uses incineration residues that cannot be utilized as concrete admixtures.

In addition, the converter slag dust is a particulate dust collected in the dust collector in the process of crushing the converter slag to adjust the particle size, the main component contains a large amount of CaO component and FeO component, and has the absorption, heat generation and expansion characteristics to be used as a concrete mixed material Since it is impossible, it is currently being disposed of in landfill.

In addition, the quicklime and light calcined dolomite are calcined limestone and dolomite at a high temperature to decarbonize and undergo a chemical reaction such as CaO contained in the incineration residue.

Hereinafter, preferred embodiments and comparative examples of the present invention will be described. In addition, the following examples are provided to illustrate the present invention and should not be understood as limiting the scope of the present invention.

Example  One

First, 30 parts by weight of petroleum coke desulfurized gypsum and 60 parts by weight of biomass incineration residue having a calcium oxide content of 47% as a swelling material were homogeneously mixed with respect to 100 parts by weight of blast furnace slag fine powder to prepare a solid mixture for a deep mixing method.

Next, add about twice the solidified amount of the solidified material, that is, 36 parts by weight of water to 18 parts by weight of the solidified material prepared as described above with respect to 100 parts by weight of the marine dredged soil to prepare a solidified soil mixed with a forced mixer to prepare 12 specimens. This was cured at 20 for 7 days.

Example  2

With respect to 100 parts by weight of marine dredged soil, 25 parts by weight of the same solidified material as in Example 1 was added twice the amount of the solidified material, that is, 50 parts by weight of water, mixed with a forced mixer to prepare a solidified soil, and 12 specimens were prepared. It was produced and cured at 20 for 7 days.

Comparative Example  One

For 100 parts by weight of marine dredged soil, Portland cement is added to 18 parts by weight twice the amount of cement, that is, 36 parts by weight of water, and then mixed with a forced mixer to produce solidified soil, and 12 specimens are produced. Cured at.

Comparative Example  2

For 100 parts by weight of marine dredged soil, Portland cement is added to 25 parts by weight twice the amount of cement, that is, 50 parts by weight of water, and then mixed with a forced mixer to produce solidified soil. Cured at.

Performance test method and result of solidified soil

As shown in Table 1 below, the permeability coefficient was tested according to the KS F 2322 Variable Permeability Test Method and the compressive strength test was performed using the KS F 2343 Uniaxial Compressive Strength Test Method.

Experiment Way Remarks Permeability coefficient KS F 2322 Variable Strain Test Method Compressive strength KS F 2343 Uniaxial Compressive Strength Test Method

(1) Permeability coefficient

Permeability coefficient test results of specimens cured at 20 for 7 days are shown in Table 2. As can be seen from Table 2, it can be seen that the permeability coefficients of Examples 1 and 2 are lower than those of Comparative Example 1 and Comparative Example 2 using only cement. As water contained in evaporated or hydrated has a relatively high permeability coefficient, in the case of solidified soils according to Examples 1 and 2, the pore water of the soil is excluded by the expansion of CaO contained in the expansion material and volume expansion occurs, resulting in low permeability. It seems to be.

division Permeability coefficient (/ sec) Compressive Strength 7 days (kgf / cm ² ) Compressive Strength Standard Deviation (kgf / cm ² ) Example 1 5.37 × 10 ^-8 35.5 2.2 Example 2 3.61 × 10 ^-8 39.8 2.5 Comparative Example 1 6.68 × 10 ^-7 18.6 5.3 Comparative Example 2 2.28 × 10 ^-7 22.3 5.7

(2) Change in uniaxial compressive strength

As shown in Table 2, the welding 7, Example 1 is 35.5 kgf / cm ^2, Example 2 was 39.8kgf / cm ^2, Comparative Example 1 is 18.6 kgf / cm ² Comparative Example 2 was found to be 22.3 kgf / cm ^{2 The} solidified material of the present invention showed a result of expressing a lot of strength compared to the ordinary Portland cement. The solidified material reacts with water and soil, resulting in the shortening of the soil particles by rapid exothermic reaction, thereby obtaining a consolidation promoting effect, and the calcium silicate reaction induced by CaO and SiO ₂ components to secure the compressive strength. This is because the reaction occurs to enhance the strength. In addition, the standard deviation of the compressive strength of each specimen was also small, so that the comparative example showed relatively stable performance compared to cement.

Claims (2)

It includes 20 to 50 parts by weight of petroleum coke desulfurized gypsum and 40 to 100 parts by weight of the expansion material based on 100 parts by weight of blast furnace slag fine powder,
The inflating material is any one or a mixture of two or more selected from the group consisting of biomass incineration residue, paper sludge incineration residue and converter slag dust,
The expansion material is ground reinforcement solid, characterized in that the calcium oxide (CaO) content is 20 ~ 70%.
The method of claim 1,
The expansion material is ground reinforcement solid, characterized in that it further comprises quicklime or light dolomite.