KR100813862B1 - Lime solidifier and the river bank repair and the reinforcement method of construction using this - Google Patents

Abstract

A lime solidifier and a repair/reinforcement method for banks of river employing the solidifier are provided to stabilize the ground while protecting the ground from deformation, to develop scenic banks of river and to recycle the solidifier for soil dressing or casting soil. A lime solidifier comprises 20-30% by weight of gypsum, 40-60% by weight of limestone, 8-10% by weight of furnace slag, 8-10% by weight of fly ash, 0.99-4.9% by weight of magnesia, 3-5% by weight of short gel time clinker mineral and 0.01-0.1% by weight of anionic coagulant. The coagulant is selected from a group consisting of electrolyte, surfactant and electrolytic polymer. A repair/reinforcement method for banks of river comprises steps of: forming mixed top soil by mixing 2-6 parts by weight of the solidifier with respect to 100 parts by weight of soil to be repaired/enforced; installing the prepared mixed top soil on the surface of the waterway of the banks of river; compacting the shallow layer of the mixed top soil installed on the surface of the waterway with a pressure.

Description

Lime solidifier and the river bank repair and the reinforcement method of construction using this}

1 is a schematic diagram showing a state of repairing and reinforcing a river embankment using a lime-based solidified material according to the present invention.

Explanation of symbols on the main parts of the drawing

AS: Target soil IS: Improved soil

RL: River Dike

The present invention relates to a lime-based fire extinguisher and a river bank repair and reinforcement method using the same, and more particularly, to a method for repairing and reinforcing a river bank using a lime-based solid fire.

In general, solidified materials are substances that solidify the soft soil, and are added to the soft ground and react with the target soil to form a solid physicochemical hardening body, which not only reinforces the ground but also solidifies the hazardous wastes, such as heavy metals contained in the water. It is known to play a role of harming and transforming into a form that is difficult to dissolve.

As the solidified material, cement or lime has been conventionally used.

In addition, cement-based ground modifiers (cement-based solidifiers) in which cement, gypsum, slag, coal ash, and alumina cement, which enhance solidification performance, have been developed and used since the 1970s. It is still being developed.

Here, although the conventional cement-based solidifying material has the advantage of improving the strength of the soft ground, there are serious environmental problems such as strong alkalinity and hexavalent chromium (Cr ⁺⁶ ) elution.

In addition, there is a problem in that it is impossible to recycle the solidified fire and target soil used for the re-construction, industrial remains.

Therefore, in order to solve the above problems and protect the environment, it is urgent to develop alternative solid fires.

Therefore, the present invention was devised to solve the problems described above, using the target soil generated locally as the main material to reduce the construction cost, to create a beautiful river bank landscape and emotion, as a cover material of solid fire The purpose of the present invention is to provide a lime-based solidified material that can be reduced and prematurely hardened, and to repair and reinforce river banks using the same.

Lime-based solidifying material according to the present invention for achieving the above object is gypsum 20-30% by weight, lime 40-60% by weight, blast furnace slag 8-10% by weight, fly ash 8-10% by weight, magnesia 0.99 ~ 4.9% by weight, 3-5% by weight of the sinterable clinker mineral, 0.01-0.1% by weight of anionic flocculant.

In addition, the river bank repair and reinforcement method using the lime-based solidified material according to the present invention for achieving the above object is to improve the soil after mixing a certain amount of solidified material to the target soil generated in the river bank, the improved After the soil is installed on the drainage surface of the river bank, the improved soil installed on the drainage surface is compacted at a constant pressure.

Hereinafter, with reference to the accompanying drawings, the present invention will be described in detail.

Lime-based solidified material according to the invention gypsum 20-30% by weight, lime 40-60% by weight, blast furnace slag 8-10% by weight, fly ash 8-10% by weight, magnesia 0.99-4.9% by weight, quick-linking clinker mineral It consists of 3 to 5 weight% and 0.01 to 0.1 weight% of anionic flocculant.

Here, the gypsum is one of the most common sulfate minerals of the chemical composition CaSO ₄ .2H ₂ O. The crystal system is monoclinic and streaks are colorless or white and split completely in one direction. It is produced from sedimentary rocks, especially salt-bearing mesozoic and mesozoic rocks, in graphite deposits, metal deposits, oxidation deposits, volcanic eruptions, hot spring sediments and soil surfaces. The shape of crystals includes parallelogram-shaped planks (dialysis gypsum), pillars, fibers (fiber gypsum), lumps (allerbaster or sulphate gypsum), and powder.

Gypsum has natural gypsum, synthetic gypsum, and by-product gypsum. In Korea, some natural gypsum is imported and used due to lack of reserves, but by-product gypsum is used. Gypsum is known to have seven different crystal forms. Isu gypsum is widely used as a cement coagulant. The calcined gypsum is heated to 150-200 ℃ and absorbed moisture in the air, which is made from half gypsum, and when it is reacted with water, it causes an exothermic reaction and returns to the original calcined gypsum. Plaster is used in various applications such as gypsum plaster, gypsum board, ceramic molds, metal molds, and medical applications. Ⅱ-anhydrite is difficult to hydrate, but hydrates if there is a stimulant such as alum. It is used in kind cement and anhydrous plaster plaster. I-free gypsum is virtually unhydrated and is called dead gypsum.

In addition, the said lime may refer to a combination of quicklime (calcium oxide) and slaked lime (calcium hydroxide), or limestone (calcium carbonate). Here, the calcium oxide is a compound of calcium and oxygen, the formula CaO. Also known as Formula 56.1, Quicklime or Lime. Cubic crystal system with melting point of 2572 ° C, boiling point of 2850 ° C and specific gravity of 3.37. The refractive index is 1.837.

It is obtained by thermal decomposition of natural limestone or calcium carbonate to about 900 ° C or higher.

CaCO ₃ → CaO + CO ₂

Currently, it is obtained by using an upright furnace or a rotary furnace. It is a white amorphous solid that is calcined at low temperature, but the crystallinity is improved when the firing temperature is increased. Large crystals can be obtained from the melt. Amorphous is very active and reacts with water at high heat to form calcium hydroxide. This is called digestion.

CaO + H ₂ O = Ca (OH) ₂ +15.2 kPa

It also reacts with carbon dioxide to produce calcium carbonate. Because of its high melting point, it is used for the interior of furnaces. In addition to raw materials such as bleach powder, carbide, cement, and glass, it is used in various fields such as lime fertilizer, soil stabilizer, disinfectant and drying agent.

In addition, the calcium hydroxide is represented by the formula Ca (OH) ₂ . Hydroxide of calcium. Formula Weight 74.1. Specific gravity is 2.24, refractive index is 1.574, and solubility is 0.126g / 100g (water 20 degreeC) and 0.077g / 100g (water 100 degreeC). Also called slaked lime.

Obtained by acting water or steam on calcium oxide (quick lime) (digestion of quicklime). Rapidly produced white powder, but when left in water, it turns into a hexagonal plate crystal. When heated, steam and decomposes at 580 ° C to return to calcium oxide.

Ca (OH) ₂ → CaO + H ₂ O

It dissolves in water only a little and its solubility decreases as the temperature rises. The aqueous solution is called lime water and has a strong basicity. Industrially, it is often used in suspension state, and it is called lime oil. It absorbs carbon dioxide in a solid or solution state and turns it into calcium carbonate that is insoluble in water.

Ca (OH) ₂ + CO ₂ → CaCO ₃ + H ₂ O

It also absorbs chlorine to form calcium hypochlorite (the main ingredient in high bleaching powders). Calcium hydroxide is an inexpensive basic substance, so it is used as a treatment agent for acidic waste, neutralizer for acidic soil, and disinfectant.

Blast furnace slag is an amorphous by-product consisting of silica (SiO ₂ ) and calcium oxide (CaO) obtained when iron is manufactured from iron ore, limestone, and coke as raw materials in the blast furnace of the steel industry. This is a molten material.

1.4 degree or more of quenched crushed bases are used for the production of blast furnace cement using its latent hydraulic properties, and those crushed in gravel form are used as concrete aggregates for roads and civil engineering. It is also used as a raw material for solidifying and soil improving materials.

In addition, the fly ash refers to the ash (coal) collected by a dust collector from the flue gas of the boiler for burning pulverized coal, the spherical particle size is about the same as cement and alumina (Al ₂ O ₃ ) and silica ( SiO ₂ ) is the main component and has long-term strength enhancement, workability improvement, drying shrinkage reduction and water-tightness increase effect, it is used in a variety of cement clinker raw materials, admixtures of concrete, building materials, ground materials, soil improvement materials.

And the magnesia is represented by the formula MgO. Compounds of magnesium and oxygen. Formula weight 40.3. Also called Goto, industrial products are called magnesia and medicines are called magnesia. Melting Point 2826 ℃, Boiling Point 3600 ℃, Specific Gravity 3.65. Its cubic crystal system has solubility of 0.62 mg / 100 g and a refractive index of 1.7364. It is obtained when the metal magnesium is heated in air, but industrially it is produced by calcining magnesium carbonate (magnesite), magnesium carbonate, magnesium hydroxide and the like. In particular, light burned magnesia made by calcining at a temperature low enough to decompose magnesium carbonate (magnesite) or magnesium hydroxide is used as a raw material for chemical industry because it is unstable and highly reactive. An important use of inorganic materials is the production of magnesia cement.

On the other hand, calcining magnesia at a high temperature of 1700 ~ 1800 ℃ gives a white crystalline solid and chemically relatively inert dead burned magnesia, which is called magnesia clinker. Iii) It is important as a raw material.

Clinker is also called agglomeration in which minerals or inorganic substances are lumped in a partially molten or semi-melted state.

Here is an example: ① Part of the ash remaining in the kiln (for ceramics) by the combustion of fuel. A lot of flux (a substance that lowers its melting point when mixed with other materials, also known as fluxes or solvents) leads to a melting point below the temperature at which ash is received, resulting in melting and melting on the kiln or on the wall.

② A mass obtained by calcining at the temperature where the mixture of limestone and clay starts to melt. When the clinker is crushed into powder, hydraulic cement such as Portland cement is obtained.

③ Calcium Sulfur Aluminate (CSA) synthesized by calcining materials such as lime, gypsum, calcined rock, etc. is widely used in civil engineering and construction because of its rapid rigidity and high strength.

④ Bricks that are deformed by accidental undersizing and partially melted during firing. This is called clinker brick. Some are made for this purpose, but others can interfere with the production process.

In addition, the anionic flocculant is a substance added to agglomerate the clade particles dispersed in a solvent and is also called a coagulant.

As a flocculant, electrolyte, surfactant, electrolyte polymer, etc. are used. For example, electrolytes contain polyvalent counter ions, such as aluminum sulfate or iron (III) chloride (Shultz-Hardy's law), and polyacrylamide or polyacrylamide derivatives as polymers. Etc. are used. The electrolyte aggregates by neutralizing the charge of the colloidal particles, and is used for a collecting agent, sewage treatment, and the like. The polymer is adsorbed around the particles, bridges the particles into large particles, aggregates, and is used as a filter aid and soil improver.

Generally, the electrolyte has a large counter charge with the particles, and the polymer has a high molecular weight. Electrolytes commonly used as flocculants include aluminum sulfate, sodium aluminate, and iron sulfate. Recently, aluminum aluminum chloride Al (OH) Cl has attracted attention.

It describes the river bank repair and reinforcement using the lime-based solidified material according to the present invention made of a configuration as described above.

River dike repair and reinforcement method using the lime-based solidified material according to the present invention is improved soil (IS) by mixing a certain amount of solidified material in the target soil (AS) generated in the river dike (RL) as shown in FIG. ), The improved soil (IS) is installed on the drainage surface of the river bank (RL), and then the improved soil (IS) installed on the drainage surface is compacted at a constant pressure.

Here, the solidified material is 20 to 30% by weight of gypsum, 40 to 60% by weight of lime, 8 to 10% by weight of blast furnace slag, 8 to 10% by weight of fly ash, 0.99 to 4.9% by weight of magnesia, 3 to 3 of quick-linking clinker minerals. It consists of 5 weight% and 0.01-0.1 weight% of anionic flocculants.

In addition, the mixing ratio of the target soil and the solidified material is blended at a ratio of 2 to 6 parts by weight of the solidified material with respect to the dry weight part 100 of the target soil.

That is, the river bank repair and reinforcement method using the lime-based solidified material according to the present invention is 20 to 30% by weight gypsum, lime to 40 to 30% by weight of the dry weight 100 of the target soil (AS) generated in the river bank (RL) Solidified material consisting of 60% by weight, blast furnace slag 8-10%, fly ash 8-10%, magnesia 0.99-4.9% by weight, 3-5% by weight of the fast-acting clinker mineral, 0.01-0.1% by weight of anionic flocculant After the mixture is formed at a proportion of ˜6 parts by weight to form the improved soil (IS), the improved soil (IS) is laid on the drainage surface of the river bank (RL), and the improved soil (IS) laid on the drainage surface is Construct by compacting the ceiling with a certain pressure.

Hereinafter, the present invention will be described in detail by way of examples.

However, the following examples are only illustrative of the present invention, the contents of the present invention is not limited to the following examples.

Example 1

Manufacture of Fire

Gypsum, lime, blast furnace slag, fly ash, magnesia, fastening clinker mineral, anionic flocculant were mixed as shown in Table 1 to prepare a solidified material.

Table 1

(Unit: weight%)

gypsum lime Blast furnace slag Fly ash magnesia Quickly Clinker Minerals Flocculant 0-30 40-60 0-20 0-30 0-10 0-10 0 to 1

Chemical components of the prepared solidified material are shown in Table 2 below.

TABLE 2

(Unit: weight%)

Solid Fire Composition  DW-1  DW-4  DW-7 SiO ₂ 10.5 25.3 21.8 Al ₂ O ₃ 4.36 6.30 5.20 CaO 79.8 53.5 61.3 MgO 1.51 1.57 1.52 Fe ₂ O ₃ 0.30 1.39 1.41 K ₂ O 0.25 0.60 0.56 Na ₂ O 0.25 0.50 0.28 Ig.loss 2.60 10.4 7.64

Example 2

Specific gravity and uniaxial compressive strength test of solid fire

The uniaxial compressive strength test (KS F 2320) was performed on the sample prepared in Example 1, and the results are shown in Table 3 below.

TABLE 3

Uniaxial compressive strength test result (㎏ / ㎠)

DW-1 DW-2 DW-3 DW-4 DW-5 DW-6 importance 3.17 3.15 3.14 3.10 3.08 3.07 7 days robbery 97.2 85.2 85.0 75.1 73.4 71.5 28 days robbery 109.5 99.7 92.5 87.7 85.2 83.5

DW-7 DW-8 DW-9 DW-10 DW-11 DW-12 importance 3.06 3.05 3.08 3.07 3.06 3.05 7 days robbery 67.9 65.3 72.9 71.4 68.8 68.3 28 days robbery 79.5 76.5 85.1 83.2 80.3 79.7

Example 3

Physical property test of the soil

1. Target soil: 1 type (Soil in Sihwa District, scheduled for test construction)

2. Physical property test (determination of basic properties of soil and classification of unified soil)

-Water content and specific gravity test of soil

-Particle size test

-Liquid and plastic limit test of soil

-Compaction test of soil

3. Epidemiological test (confirms soil's own strength and permeability)

-Subgrade soil bearing ratio test

-Soil permeability test

Table 4

The soil properties

Properties Result Depth (m) 0 to 1  Granularity Jar (more than 4.75mm) 0.0 Sand (0.075-4.75 mm) 0.7 Seal (0.005-0.075mm) 75.2 Clay (0.005 mm or less) 24.1  Roughness Liquid Limit LL (%) 44.0 Firing Limit PL (%) 22.7 Plasticity Index PI (%) 21.3 Unified soil classification (U.S.C.S) CL Specific Gravity 2.662 Natural Function Ratio (ω _n ) (%) 41.2 Subsoil Bearing Capacity (C.B.R.) 5.0 Permeability coefficient (K, cm / s) 2.48 × 10 ^-6

Example 4

Solidified fire-target soil test

1. Use soil: site of Sihwa district test and construction site (CL)

2. Fires: 12 types of fires developed by Doowon C & C (DW-1 ~ DW12)

3. Mixing ratio: ratio of solidified fire to dry weight of target soil (2%, 4%, 6%)

4. Age of aging: 7 days, 28 days, 60 days, 120 days

5. Test Items

-Uniaxial compressive strength test

-Freeze thaw test

Permeability test

Table 5

7-day uniaxial compressive strength test results

 Compounding cost  DW-1  DW-2  DW-3  DW-4  DW-5  DW-6  Remarks  2%  4.55  4.3  4.93  3.73  3.62  3.49  Uniaxial compressive strength  4%  6.2  7.2  6.3  5.1  4.96  4.69  (㎏ / ㎠) 7 days old  6%  7.3  10  8.8  5.35  5.11  5.05  Wet Curing

 Compounding cost  DW-7  DW-8  DW-9  DW-10  DW-11  DW-12  Remarks  2%  2.87  3.55  2.98  3.38  3.07  3.97  Uniaxial compressive strength  4%  4.75  4.54  4.99  4.98  4.85  4.80  (㎏ / ㎠) 7 days old  6%  5.17  5.05  5.02  5.03  5.12  5.09  Wet Curing

Table 6

Compound test result (1)

TABLE 7

Compound test result (2)

Table 8

Compound test result (3)

Table 9

DW-4 compound test result (compressive strength)

Table 10

DW-4 Mixing Soil Permeation Test

Table 11

DW-4 Mixing Soil Permeability Test

 DW-4 compounding ratio  7 days (wet curing)  28 days (wet curing)  60 days (wet curing)  120 days (wet curing)  Remarks  0%  2.48E-06  2.48E-06  2.48E-06  2.48E-06 Permeability (cm / sec) Target Permeability (1 × 10 ^-7 cm / sec or less)  2%  7.30E-07  6.90E-07  6.20E-07  5.80E-07  4%  9.99E-08  9.91E-08  9.90E-08  9.88E-08  6%  9.87E-08  8.80E-08  8.73E-08  8.63E-08

Example 5

Field test construction

1. Target route: Drainage in Shihwa District Reclaimed Land (Daesong 2 section)

2. Scale: 0.5m (low width) × 60m (length) × 2m (slope length)

3. Fire: Development of Doowon C & C Fire

4. Added amount of fire

4% (section 20m), 6% (section 20m), 20% (section 20m)

5. Field applicability evaluation

Age: 7, 28, 60 and 120 days

-Core extraction uniaxial compressive strength test

 Table 12

Field core compressive strength test results

division Curing period Compressive strength (㎏ / ㎠) Remarks 0 to 20 m  1 week 5.23 4% mixed soil section 20-40 m 5.50 6% mixed soil section 40 to 60 m 10.3 20% mixed soil section

Example 6

Heavy Fire Dissolution Test Results

Table 13 Heavy Metal Dissolution Test of Solidified Material

Heavy metal type Detection amount Pb N.D. CD N.D. Cr ^{6 +} N.D. Cu N.D. As N.D. Hg N.D.

As described above, the lime-based solidified material and the river bank repair and reinforcement method using the same according to the present invention has the following effects.

First, the present invention has a ground stability effect through a decrease in the water content of high moisture content soft soil.

Second, the present invention has an advantage that is suitable for structures such as roads, water slopes, waste landfill bottom layer requiring long-term strength and high durability.

In particular, when applied to the road there is an excellent crack prevention effect.

Third, the present invention has the effect of reducing the effect of the climate because the structure is capable of premature curing of about 3 to 7 days.

Fourth, the present invention has the effect of preventing the ground deformation caused by the rise of the groundwater level.

Fifth, the present invention has the effect of reducing the construction cost by using the target soil as the main material.

Sixth, the present invention has the advantage of creating a beautiful landscape and emotion by applying in a suitable method for the local environment.

Seventh, the present invention has the advantage that can be reused as soil for soil, cover soil when the solidified fire method is reduced to soil, compared to the concrete construction method is generated waste.

Claims (4)

20-30% by weight of gypsum, 40-60% by weight of lime, 8-10% by weight of blast furnace slag, 8-10% by weight of fly ash, 0.99-4.9% by weight of magnesia, 3-5% by weight of fastener clinker minerals, anionic A lime-based solidified material, characterized by comprising 0.01 to 0.1% by weight of a flocculant. After mixing a certain amount of solidified material with the target soil generated from the river bank to form the improved soil, the improved soil is laid on the drainage surface of the river bank and the improved soil laid on the drainage surface is compacted at a constant pressure. River dike repair and reinforcement method using lime-based solidified fire, characterized in that the construction. The method of claim 2, The solidified material is 20 to 30% by weight of gypsum, 40 to 60% by weight of lime, 8 to 10% by weight of blast furnace slag, 8 to 10% by weight of fly ash, 0.99 to 4.9% by weight of magnesia, 3 to 5% of fastenable clinker mineral %, River dike repair and reinforcement method using a lime-based solidified material, characterized in that consisting of 0.01 to 0.1% by weight of anionic flocculant. The method of claim 2, The mixing ratio of the target soil and solidified material is a river dike repair and reinforcement method using a lime-based solidified material, characterized in that blended in a ratio of 2 to 6 parts by weight of solidified material with respect to the dry weight 100 of the target soil.

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