KR100901107B1 - A method and apparatus for manufacturing lightweight foamed soils - Google Patents

Abstract

A method and an apparatus for producing lightweight foamed soil are provided to produce lightweight foamed soil serving as a constructional material with excellent environment-friendly properties by adding a solidifying agent and foam to dredged soil. A method for producing lightweight foamed soil comprises the following steps of: mixing soil and water to prepare slurry(S3-1); mixing the slurry and cement, of which the amount is determined according to an equation of qu28 = AxB-2.12 in order to add soluble silicate, bentonite or lime to the slurry(S3-2); and mixing a foaming agent with the cement-containing slurry(S3-3). In the equation, the 'qu28' represents 28-day unconfined compression strength; and the 'A' and 'B' indicate a proportional factor and a material coefficient respectively. The soil is construction residue or soil separated from dredged soil. The water is added twice as much as the liquid limit to the soil in order to make slurry.

Description

A method and apparatus for manufacturing lightweight foamed soils

The present invention relates to a method and manufacturing apparatus for producing a mixed bubble soil, and more particularly, a method and a manufacturing method for producing a mixed bubble soil using earth and sand in a remnant soil and a dredged soil dump site at a construction site in order to resource a large amount of dredged soil or construction-produced soil. Relates to a device.

In general, part of the coastal area is reclaimed for the construction of roads and complexes for the efficient use of the country, and industrial complexes, housing complexes, amusement complexes and airports are established.

The conventional reclamation work consists of constructing a quayside revetment, pumping the dredged soil from the seabed outside the lake, and forming a surface layer on which the heavy equipment can run and work on the dredged landfill.

Dredged soil is very soft, and various ground improvement methods are introduced to stabilize the ground, but it is very disadvantageous in terms of economic feasibility due to expensive construction methods and improvement time.

In order to solve these problems, research on the ground improvement method and light mixed soil is being conducted. In order to realize pollution prevention of marine environment, effective use of resources, and shortening construction air, light weight, high strength, durability, eco-friendly It is a situation to study the practical use plan from various angles such as sex.

In the case of conventional light mixed soils, land soils such as construction soils are generally used, and vegetable foaming agents and fresh water have been used to give certainty of foaming.

However, the above method is suitable for small-scale construction of land due to lack of flexibility in supplying materials and narrow working space, and has many problems in supplying and supplying construction materials in accordance with large-scale port construction.

In particular, the lightweight mixed soil containing bubbles has a problem that the design of the ground design constant is very difficult due to the bubble effect, unlike the cement mixed soil which is used for strength enhancement.

An object of the present invention is presently generated in large quantities in the construction site, but is classified as construction waste, mixed with mixed soil that can improve the construction residue and dredged soil having a lot of problems in the treatment to environmentally friendly and engineering properties construction materials It is to provide a manufacturing method and a manufacturing apparatus.

In other words, the use of solidified materials, such as cement, for the construction residues or dredged soils to enhance the strength and prevent the spread of contaminants. It is to provide a method and apparatus for producing a bubble mixing soil which is artificial ground.

Bubble mixing process according to the invention manufacturing method, (a) mixing the soil and water to make a slurry; (b) q _u28 = A × B- ^2. Mixing cement with the slurry in an amount determined by ¹² equation, where q _u28 is the uniaxial compressive strength (kPA), A is the proportional constant and B is the material coefficient; And (c) mixing the foaming agent with the cement mixed slurry, wherein the soil is earth and sand classified from construction residue or dredged soil, and mixes water so as to double the liquid limit of the soil to make a slurry, A is 18.7 to 21.4, wherein B is [(ω _i × A _r ) / C _i ], where ω _i is the weight ratio of soil to soil, A _r is the weight ratio of foam to soil, and C _i Is a weight ratio of cement to soil sand), and the dilution ratio of the foaming agent and water is 1:23, the foaming ratio is 25 times, and the air pressure is preferably foamed under 2 to 3 kg / cm ² .

In addition, the step (b) preferably comprises the step of adding soluble silicate, bentonite or lime, and in the step (c), the foaming agent is preferably an animal foaming agent.
Bubble mixing process according to the invention manufacturing method, (a) mixing the soil and water to make a slurry; (b) mixing cement with the slurry and adding soluble silicate, bentonite or lime to the slurry; (c) mixing the foaming agent in the slurry in which the cement is mixed.

In the bubble-mixed soil producing apparatus according to the present invention, the soil classified from the construction residue or dredged soil is mixed with water and cement, and the amount of water is determined to be twice the liquid limit of the soil, and the amount of cement is q _u28 = A x B ^-2.12 equation (where q _u28 is the 28-day uniaxial compressive strength (kPA), A is 18.7 to 21.4, and B is (ω _i × A _r ) / C _i ) to form cement mixture slurry Mixing tank; A pressure feeding device connected to the mixing tank and pumping the cement mixing slurry; A bubble generator for generating bubbles using an animal bubble agent; And a bubble mixing device for mixing the cement mixture slurry fed by the pressure feeding device with the bubbles generated by the bubble generating device.

The mixing tank is agitated the cement mixing slurry by a biaxial screw, the bubble mixing device, the tubular housing in which the cement mixing slurry flows; A mixing rod located at the center of the housing along a flow direction of the cement mixing slurry; And a plurality of mixing blades positioned on an outer circumferential surface of the mixing rod.
The apparatus for producing bubble mixed soil according to the present invention includes: a mixing tank in which soil classified from construction residue or dredged soil is mixed with water and cement to form a cement mixture slurry; A pressure feeding device connected to the mixing tank and pumping the cement mixing slurry; A bubble generator for generating bubbles using an animal bubble agent; And a bubble mixing device for mixing the cement mixing slurry pushed by the pressure feeding device and the bubbles generated by the bubble generating device, wherein the bubble mixing device has a tubular housing in which the cement mixing slurry flows. ; A mixing rod located at the center of the housing along a flow direction of the cement mixing slurry; And a plurality of mixing blades positioned on an outer circumferential surface of the mixing rod, wherein the cement mixing slurry flows while forming a vortex by the mixing blades.

The method and apparatus for preparing mixed bubble soil according to the present invention solves social, economic and environmental problems of construction residue and dredged soil which are classified as construction waste and landfilled and dumped offshore.

In other words, the method and manufacturing apparatus for mixing the bubble mixture soil according to the present invention by mixing the solidified material and bubbles in the dredged soil, the foam mixture treated soil having an environmentally friendly and engineering excellent properties (strength, lightweight, etc.) construction material It has the effect of making it easy to apply at the construction site by providing the formula to design the compressive strength according to the mixing ratio of each component of the bubble mixing soil.

In addition, the bubble mixing soil manufacturing apparatus according to the present invention has the effect of making the mixing of the bubbles homogeneous by forming a vortex by the hydraulic cylinder and the mixing blades, without rotating the rotary rod of the bubble mixing device when mixing the bubbles.

Hereinafter, with reference to the accompanying drawings, a method and manufacturing apparatus for producing a mixed bubble soil according to an embodiment of the present invention will be described in detail.

1 is a flow chart of a method for manufacturing a bubble mixture soil according to an embodiment of the present invention.

Bubble mixing process according to an embodiment of the present invention manufacturing method can be seen as a large preparation step (S1), classification step (S2), stirring step (S3), the pouring step (S4) for the construction of the bubble mixing process ) May be further included. Here, the bubble mixing soil produced by the bubble mixing soil preparation method according to an embodiment of the present invention is also called smart soil (smartsoil).

The preparation step (S1) is a step of obtaining a large amount of dredged soil generated from various dredging purposes each year from the dredged soil dumping site. The earth and sand prepared in the preparation step (S1) of the present invention is preferably dredged soil in a supersaturated state, but is not necessarily limited thereto, and various types of earth and sand may be used.

The sorting step (S2) is divided into a step (S2-1) for classifying the soil from the construction residue or dredged soil using a screen (S2-2) and a step (S2-2) for transferring the classified soil. The screen size is preferably 10 mm.

Stirring step (S3) is a step of forming a slurry by putting a predetermined amount of water in the soil (S3-1), mixing the solidifying material in the slurry (S3-2) and mixing the foaming agent in the slurry (S3- Include 3).

In the step (S3-1) of forming a slurry by adding a predetermined amount of water to the soil, water is added to the classified soil to be about 2 times (2ω _L ) the liquid limit obtained through the indoor soil test on the classified soil. When the amount is more than 2 times, the strength is decreased, and when the amount is less than 2 times, the fluidity is decreased, so the 2 times is most preferable. After the watering is carried out, stirring is performed to allow sufficient mud to be removed.

In the step (S3-2) of mixing the solidified material with the slurry, cement is preferably used as the solidified material. For the slurry produced in the S3-1 step, the slump value is expressed with respect to 200 mm based on the target uniaxial compressive strength according to the civil engineering structure. The amount of cement is determined by (1) and (2).

q _u28 = A × B ^-2.12 (kPA) Equation (1)

B = (ω _i × A _r ) / C _i Formula (2)

Where q _u28 is the uniaxial compressive strength of 28 days. A is a proportionality constant, and 18.7-18.7-21.4 are preferable. In addition, B is the material coefficient, ω _i is the weight ratio of the soil to the soil, A _r is the weight ratio of the soil to the sand, C _i represents the weight ratio of the soil to the soil.

In the cement mixed in step S3-2, when the particles react with water to cause hydration, heavy metals, which may be included in the dredged soil, are involved in the hydration reaction of the cement and form a chelate compound to form a chemical. Is fixed.

In addition, Cd, Zn, Pb in the heavy metal is selectively precipitated on the cement surface is stabilized. At this time, Cd and Zn react with Ca (OH) ₂ to precipitate as hydroxides of CaCd (OH) ₄ and CaZn ₂ (OH) ₆ .2H ₂ O forms, which are insoluble compounds, to stabilize.

In solidification by cement of hazardous waste that may be included in construction residue or dredged soil, additives may be used to improve the elution characteristics of the hazardous substances or to promote the hydration reaction with cement. As these additives, soluble silicates such as sodium silicate, potassium silicate and the like are preferable. In addition, clays such as bentonite improve the elution properties through moisture control and pollutant absorption, and lime can improve the coagulation properties by increasing the pH and temperature.

In the step of mixing the foaming agent in the cement mixture slurry (S3-3) in order to give light weight to the slurry mixed with the cement in step S3-2 by using a bubble generator in the bubble volume of 30 ~ 60% of the slurry volume mixed with the cement Mix it.

Foaming agents include animal, vegetable, synthetic oil, and the like, and physically mix bubbles by using a surface active action. In this embodiment, the animal foaming agent which proved the certainty of foaming in the seawater environment which is a soil generation environment is preferable.

On the other hand, examples of the amount of cement that can be determined by the formula (1) and formula (2) of the stirring step (S3) are illustrated in Table 1, the values illustrated in Table 1 is a dilution ratio of the foaming agent and water is 1:23, foaming The magnification was about 25 times and based on the bubble foamed under the air pressure 2-3 kg / cm <^2> .

 Soil / Cement Ratio (weight ratio) 28-day target uniaxial compressive strength (kPa)  Bubble mixing rate (%) Bubble amount (kg / m ³ ) Amount of cement (kg / m ³ ) Soil volume (kg / m ³ ) Quantity (kg / m ³ ) Wet Unit Weight (t / m ³ )  3 280 54 0.94 156 468 231 0.86 400 51 0.89 169 507 243 0.92 620 47 0.82 186 558 258 1.00 850 44.5 0.77 197 591 266 1.05  4 330 51.5 0.89 138 552 233 0.92 480 48 0.83 149 596 246 0.99 730 44 0.76 162 648 261 1.07 940 41.5 0.72 170 680 270 1.12  5 380 48.5 0.84 125 625 239 0.99 530 45 0.78 134 670 253 1.06 890 40 0.69 148 740 273 1.16 1200 37 0.64 156 780 284 1.22

In order to confirm the workability of the bubble mixture soil slurry prepared by one embodiment of the present invention, it is preferable to check whether the slump value is 200 mm or more. Thereafter, the pouring step S4 may be performed.

2 is a schematic conceptual view of an apparatus for preparing bubble mixed soil according to an embodiment of the present invention. Figure 3 is a perspective view showing the pressure-feeding device and the bubble mixing device of the bubble mixing soil manufacturing apparatus according to an embodiment of the present invention.

Bubble mixing soil manufacturing method according to an embodiment of the present invention described above, the mixing tank 110 to form a cement mixture slurry by injecting water and cement into the dredged soil to be introduced; A pressure feeding device (120) connected to the mixing tank (110) to pump cement mixing slurry into the bubble mixing device (140); Bubble generator 130 for generating bubbles by using an animal foam agent that can give a certainty of foaming in the sea water environment; And it can be carried out by the bubble mixing soil manufacturing apparatus comprising a bubble mixing device 140 in charge of mixing with the bubbles by the pressure of the cement mixing slurry.

The mixing tank 110 forms a slurry by mixing water with soil separated from the construction residue or dredged soil to form a slurry, followed by cement injection to form a cement mixture slurry. This stirring process is performed by a biaxial screw.

The pressure feeding device 120 pushes the cement mixing slurry formed in the mixing tank 110 into the bubble mixing device 140 by the hydraulic cylinder 121.

The bubble generator 130 has a compressor for producing compressed air for bubble generation and a bubble storage tank for supplying a bubble agent, and the bubbles generated by these are transferred to the bubble mixing device 140.

Bubble mixing device 140 is a device consisting of a tube-shaped housing 141 for mixing the bubble mixed from the cement mixing slurry conveyed by the pressure feeding device 120 from the mixing tank 110 and the bubble generating device 130. .

The mixing rod 142 is positioned at the center of the housing 141 along the flow of the cement mixing slurry that is conveyed to the inside of the bubble mixing device 140, and the plurality of mixing blades 143 is disposed on the outer circumferential surface of the mixing rod 142. Although the mixing rod 142 itself does not rotate but the cement mixing slurry flowing by the pressure feeding pressure forms the vortex by the mixing blades 143, and the bubbles injected into the vortex flowing cement mixing slurry are homogeneously mixed. do.

The illustrative embodiments described above are intended to be illustrative within all aspects of the invention rather than limiting. Accordingly, the present invention is capable of many modifications and implementations that can be made by those skilled in the art from the description contained herein. All such modifications and variations are considered to be within the scope and spirit of the invention as defined by the following claims.

1 is a flow chart of a method for manufacturing a bubble mixture soil according to an embodiment of the present invention.

2 is a schematic conceptual view of an apparatus for preparing bubble mixed soil according to an embodiment of the present invention.

Figure 3 is a perspective view showing the pressure-feeding device and the bubble mixing device of the bubble mixing soil manufacturing apparatus according to an embodiment of the present invention.

Claims (13)

In the bubble mixing process manufacturing method, (a) mixing the soil and water to make a slurry; (b) mixing cement with the slurry in an amount determined according to the formula q _u28 = A x B ^-2.12 , and adding soluble silicate, bentonite or lime to the slurry; (c) mixing the foaming agent in the slurry in which the cement is mixed; Q _u28 of the above formula is 28 days uniaxial compressive strength (kPA), A is a proportional constant, B is a method of manufacturing a mixed bubble soil, characterized in that the material coefficient. The method of claim 1, wherein in step (a), The soil is a soil classified from construction residue or dredged soil, Method for producing a mixed-bubble soil, characterized in that to make a slurry by mixing water so as to be twice the liquid limit of the soil. The method of claim 1, wherein in step (b), The soil is a soil classified from construction residue or dredged soil, A is 18.7 to 21.4, and B is [(ω _i × A _r ) / C _i ], ω _i is the weight ratio of soil to soil, A _r is the weight ratio of foam to soil, and C _i is the weight ratio of cement to soil. delete The method of claim 1, wherein in step (c), The foaming agent is a mixed foamed soil manufacturing method, characterized in that the animal foaming agent. The method of claim 1, wherein in step (c), The soil is a soil classified from construction residue or dredged soil, Dilution ratio of the foaming agent and water is 1:23, the foaming ratio is 25 times, the air pressure is foamed mixed soil manufacturing method characterized in that the foaming foam under 2 to 3kg / cm ² . Soil classified from construction residue or dredged soil is mixed with water and cement, and the amount of water is determined to be twice the liquid limit of the soil, and the amount of cement is determined according to the equation q _u28 = A × B ^-2.12. A mixing tank in which a slurry is formed; A pressure feeding device connected to the mixing tank and pumping the cement mixing slurry; A bubble generator for generating bubbles using an animal bubble agent; And And a bubble mixing device for mixing the cement mixture slurry pushed by the pressure feeding device with the bubbles generated by the bubble generating device, Q _u28 is the uniaxial compressive strength (kPA) of 28 days, A is 18.7 to 21.4, B is determined by [(ω _i × A _r ) / C _i ], ω _i is the weight ratio of the soil to the soil , A _r is the weight ratio of foam to the soil, C _i is the weight ratio of cement to the soil, The bubble mixing device A tubular housing through which the cement mixing slurry flows; A mixing rod located at the center of the housing along a flow direction of the cement mixing slurry; And Including a plurality of mixing blades located on the outer peripheral surface of the mixing rod, The cement mixing slurry is bubble mixing soil manufacturing apparatus characterized in that the flow by forming the vortex by the mixing blades. 8. The bubble mixing apparatus of claim 7, wherein the mixing tank agitates the cement mixture slurry by a biaxial screw. delete In the bubble mixing process manufacturing method, (a) mixing the soil and water to make a slurry; (b) mixing cement with the slurry and adding soluble silicate, bentonite or lime to the slurry; (C) a method for producing a mixed bubble mixture soil comprising the step of mixing a foaming agent in the slurry of the cement. The method of claim 10, wherein in step (c), The foaming agent is a mixed foamed soil manufacturing method, characterized in that the animal foaming agent. A mixing tank in which the soil classified from the construction residue or dredged soil is mixed with water and cement to form a cement mixing slurry; A pressure feeding device connected to the mixing tank and pumping the cement mixing slurry; A bubble generator for generating bubbles using an animal bubble agent; And And a bubble mixing device for mixing the cement mixture slurry pushed by the pressure feeding device with the bubbles generated by the bubble generating device, The bubble mixing device A tubular housing through which the cement mixing slurry flows; A mixing rod located at the center of the housing along a flow direction of the cement mixing slurry; And Including a plurality of mixing blades located on the outer peripheral surface of the mixing rod, The cement mixing slurry is bubble mixing soil manufacturing apparatus characterized in that the flow by forming the vortex by the mixing blades. The apparatus of claim 12, wherein the mixing tank is agitated by the cement mixing slurry by a biaxial screw.

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