KR20220029839A - Eco friendly injection for ground reinforcement grout composition and construction method using the same - Google Patents

Abstract

Disclosed is a high-strength grout composition, which shows improved gel time performance due to controlled hydration reaction, while being eco-friendly by containing a large amount of industrial by-products. A grout composition for ground reinforcement injection of the present invention consists of a quick-setting composition and an inorganic composition. The quick-setting composition comprises: amorphous calcium sulfoaluminate powder; anhydrite powder; desulfurized gypsum powder; and a reactant. The inorganic composition comprises: ordinary Portland cement; blast furnace slag powder; paper ash; and circulating fluidized bed boiler ash.

Description

Eco friendly injection for ground reinforcement grout composition and construction method using the same}

The present invention relates to a ground injection reinforcement grout composition and a construction method using the same, and more particularly, to a ground injection reinforcement grout composition based on an eco-friendly material and a construction method using the same.

In general, various types of water such as groundwater, river runoff, and rainwater exist in the ground. Such water in the ground penetrates into cracks in underground structures and facilities and causes internal rebar corrosion and cracks to expand, reducing durability or causing problems such as leakage through cracks. To prevent this, ground reinforcement is currently being carried out prior to civil engineering work, and among these reinforcement methods for soft ground, a method of solidifying the target ground by injecting and spraying grout through an injection pipe into a gap in the soil or rock is proposed. This is called the grouting technique.

A mortar that is widely used as such a reinforcing grout composition is a mortar usually mixed with a small amount of gravel, sand, and cementitious and mixed with water. However, since most of the components of the mortar grout composition are cement-based, there is a problem in that an ignition material is generated along with the toxicity of the cement-based system, thereby contaminating the surrounding environment. In particular, when the mortar grout composition is filled in the gaps of the building structure, there are problems such as having a serious impact on the residential environment due to the harmful components of cementitious substances, and contaminating the surrounding soil when applied to water repellency and soft ground reinforcement.

[Prior Patent Literature]

- Korean Patent Registration No. 10-1662721 (2016.09.28.)

- Korean Patent Registration No. 10-1709239 (2017.02.16.)

Accordingly, an object of the present invention is to provide a high-strength grout composition containing a large amount of industrial by-products, which is eco-friendly and has improved gel time performance through hydration reaction control, and a ground injection reinforcement construction method using the same.

In order to solve the above problems, the present invention provides a ground injection reinforcement grout composition comprising a rapid setting composition and an inorganic composition, wherein the rapid setting composition includes amorphous calcium sulfoaluminate powder, anhydrite powder, desulfurized gypsum powder and a reactant , The inorganic composition provides a ground injection reinforcement grout composition comprising ordinary Portland cement, blast furnace slag powder, paper ash and circulating fluidized bed boiler ash.

In addition, the rapid setting composition comprises 37 to 67% by weight of the amorphous calcium sulfoaluminate powder, 12 to 32% by weight of the anhydrite powder, 10 to 25% by weight of the desulfurized gypsum powder, and 2 to 15% by weight of the reactant , The inorganic composition comprises 30 to 60% by weight of the ordinary Portland cement, 15 to 35% by weight of the blast furnace slag powder, 5 to 25% by weight of the papermaking ash, and 5 to 25% by weight of the circulating fluidized bed boiler ash, It provides a ground injection reinforcement grout composition, characterized in that the weight ratio of the settlement composition and the inorganic composition is 1:1 to 1:5.

In addition, the paper ash contains at least 55 wt% of calcium oxide (CaO) and at least 10 wt% of silicon dioxide (SiO ₂ ), and the circulating fluidized bed boiler ash contains at least 45 wt% of calcium oxide (CaO) and silicon dioxide ( SiO ₂ ) Provides a ground injection reinforcement grout composition, characterized in that it contains 8% by weight or more.

In order to solve the another problem, the present invention is a ground injection reinforcement construction method using a grout composition, wherein the liquid A containing the quick-setting composition and the liquid B containing the inorganic composition are each separately pumped in equal amounts It provides a ground injection reinforcement construction method using a 1.5-shot type grout composition, which is sent to the Y tube and supplied in a mixed state in the injection tube connected to the Y tube, and the filler is sprayed into the ground through the through hole formed at the bottom. do.

In addition, as a ground injection reinforcement construction method using a grout composition, the liquid A containing the quick-setting composition and the liquid B containing the inorganic composition are sent to the underground through a double injection pipe and mixed in the underground 2.0 shot method. Provided is a method for reinforcing ground injection using a grout composition.

According to the present invention, in the ground injection reinforcing grout composition comprising a quick-setting composition and an inorganic composition, amorphous calcium sulfoaluminate powder, anhydrite powder and desulfurized gypsum powder are included as the quick-setting composition, and a large amount of industrial by-products as an inorganic composition However, by containing a specific amount of paper ash and circulating fluidized bed boiler ash, it is possible to provide an eco-friendly grout composition with improved gel time performance as well as realization of high strength through hydration reaction control and a ground injection reinforcement construction method using the same.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, if it is determined that a detailed description of a related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted. Also, throughout the specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

As a result of repeated research to develop a high-strength grout composition with improved gel-time performance and eco-friendly by containing a large amount of industrial by-products in the ground injection reinforcement grout composition composed of a quick-setting composition and an inorganic composition, the present inventors have made amorphous into a quick-setting composition. It contains calcium sulfoaluminate powder, anhydrite powder and desulfurized gypsum powder, and contains a large amount of industrial by-products as an inorganic composition, but contains a certain amount of paper ash and circulating fluidized bed boiler ash to achieve high strength through hydration reaction control as well as gel It has been discovered that time performance can be improved and the present invention has been led.

Accordingly, the present invention provides a ground injection reinforcing grout composition comprising a rapid setting composition and an inorganic composition, wherein the rapid setting composition includes amorphous calcium sulfoaluminate powder, anhydrite powder, desulfurized gypsum powder and a reactive agent, and the inorganic composition is usually Disclosed is a ground injection reinforcement grout composition comprising Portland cement, blast furnace slag powder, paper ash and circulating fluidized bed boiler ash.

The ground injection reinforcing grout composition according to the present invention is a quick-setting composition (also called 'agent A' in the present invention, and a composition containing water is called 'solution A') and an inorganic composition (also called 'agent B' in the present invention) , a composition containing water is referred to as 'liquid B'), so when a quick-setting composition and an inorganic composition are mixed, a quick-setting solid can be formed. It can be suitably used to inject inorganic grout into

Amorphous calcium sulfoaluminate powder (C12A7), anhydrite powder and desulfurized gypsum powder constituting the quick-setting composition are components constituting the CSA-based expanding agent for non-shrinkage realization, and in the present invention, It may consist of a composition corresponding to a particular composition.

That is, in the present invention, the rapid setting composition comprises 37 to 67% by weight of the amorphous calcium sulfoaluminate powder, 12 to 32% by weight of the anhydrite powder, 10 to 25% by weight of the desulfurized gypsum powder, and the reactant. may be included in an amount of 2 to 15% by weight, preferably 42 to 62% by weight of the amorphous calcium sulfoaluminate powder, 12 to 32% by weight of the anhydrite powder, and 10 to 25% by weight of the desulfurized gypsum powder and 2 to 15% by weight of the reactant.

The reactant is not particularly limited to a chemical that reacts with the main material in the chemical to form a gel, and for example, a curing accelerator such as sodium silicate or sodium sulfate may be used.

The inorganic composition is a component constituting the binder of the grout composition according to the present invention, and the present invention proposes a special composition for improving the gel time performance with high strength while including a large amount of industrial by-products.

That is, in the present invention, the inorganic composition contains 30 to 60% by weight of the ordinary Portland cement, 15 to 35% by weight of the blast furnace slag powder, 5 to 25% by weight of the paper ash, and 5 to 25% by weight of the circulating fluidized bed boiler ash. It may include by weight, preferably 35 to 55% by weight of the ordinary Portland cement, 20 to 30% by weight of the blast furnace slag powder, 10 to 20% by weight of the paper ash, and 10 to 20% by weight of the circulating fluidized bed boiler ash It may contain 20% by weight.

As described above, in the present invention, the blast furnace slag powder, paper ash and the circulating fluidized bed boiler ash as industrial by-products among the components constituting the inorganic composition are preferably 40 to 70% by weight, more preferably 50 to 65% by weight. It is possible to improve the gel time performance together with the high strength of the grout composition while containing it.

The blast furnace slag powder is obtained by pulverizing blast furnace slag generated during iron and steelmaking to a certain fineness. It does not have hydraulic properties by itself, but is a latent hydraulic material that has hydraulic properties when coexisted with alkaline materials such as cement. Reactivity with amorphous materials It has the property of inducing the generation of hydrates and the expression of strength. The fineness of the blast furnace slag powder may be 3,000 to 7,000 cm2/g, preferably 4,000 to 6,000 cm2/g.

The paper ash is ash generated by incineration of paper sludge. Calcium carbonate (CaCO3) undergoes a calcination reaction according to the incineration process to generate a large amount of calcium oxide (CaO), and as the crystals become finer, the specific surface area increases. It is an industrial by-product that increases reactivity.

In the present invention, the paper ash may contain 55 wt% or more of calcium oxide (CaO) and 10 wt% or more of silicon dioxide (SiO2), preferably 55 to 65 wt% of calcium oxide (CaO) and silicon dioxide (SiO2) may be contained in an amount of 10 to 20% by weight. When calcium oxide is contained in the above content range, portlandite (Ca(OH) ₂ ) is produced by digesting pore water, which not only promotes initial reactivity, but also reacts with silicate and aluminate in soil to form hydrate (calcium) silicate or calcium aluminate), and the like, so that the strength and gel time performance of the grout composition can be improved.

In the present invention, the paper ash is included in an amount of 5 to 25% by weight, preferably 10 to 20% by weight, in the inorganic composition as described above, and when the content is excessive, the strength and gel time performance of the grout composition are reduced rather deteriorated. However, it has been found to significantly improve the strength and gel time performance of the grout composition when used in combination with a circulating fluidized bed boiler ash of a similar content level.

The paper ash may have a specific gravity of 2.7 level, and a fineness of 3,600 cm 2 /g or more, preferably 3,600 to 5,000 cm 2 /g.

The circulating fluidized bed boiler ash is an industrial by-product generated in a cogeneration plant, also called 'cogeneration ash', and is classified as a kind of fly ash.

In the present invention, the circulating fluidized bed boiler ash may contain 45 wt% or more of calcium oxide (CaO) and 8 wt% or more of silicon dioxide (SiO ₂ ), preferably 45 to 55 wt% of calcium oxide (CaO) and 8 to 20 wt% of silicon dioxide (SiO2). Like the paper ash, the circulating fluidized bed boiler ash contributes to the improvement of strength and gel time performance by containing calcium oxide in the above content range.

In the present invention, the circulating fluidized bed boiler ash is included in an amount of 5 to 25% by weight, preferably 10 to 20% by weight, in the inorganic composition as described above. Although the time performance is rather deteriorated, the strength and gel time performance of the grout composition are significantly improved by being used in combination with the paper ash at a similar content level.

The circulating fluidized bed boiler ash may have a specific gravity of 2.6 and a fineness of 2,700 cm 2 /g or more, preferably 2,700 to 4,000 cm 2 /g.

In general, in the manufacture of grout compositions, bentonite has been mainly used in the ground injection material to control the initial pore number, but bentonite may have an adverse effect on the environment. Accordingly, in the present invention, 40 to 70% by weight of the binder constituting the B liquid (suspension) by selecting paper ash and circulating fluidized bed boiler ash as a material that can act as bentonite, preferably 50% or more. By using by-products, eco-friendliness can be secured.

On the other hand, in the present invention, the weight ratio of the quick-setting composition and the inorganic composition is 1:1 to apply each composition of the quick-setting composition and the inorganic composition to realize high strength of the grout composition and improve the gel time performance. It may be 1:5, preferably 1:2 to 1:4.

The above ground injection construction using the grout composition according to the present invention may follow a conventional method, for example, by applying a grout injection method such as LW (Labiles Wasserglass), SGR (Space Grouting Rocket System) method, 1.5 shot (shot) ) or 2.0 shot (double injection tube method) can be used for grout injection.

In the 1.5 shot method, two chemical solutions are sent at the same pressure at the same pressure through separate pumps, and the heterogeneous solution is supplied in a mixed state in the injection tube connected to the Y tube, and the filler is sprayed into the ground through the through hole formed at the bottom. can be done in this way.

The 2.0 shot method is a method in which two chemical liquids are sent to the underground and mixed underground. and these chemical solutions are mixed underground.

The LW method is a representative method of the 1.5 shot injection method, and in general, water glass (sodium silicate) and cement milk are mixed and injected. It is mainly capable of penetrating the gravel layer or the sand layer, and is used for the purpose of preventing settlement or strengthening the ground by injecting it into the soft clay or silt layer.

The SGR method is a representative method of the 2.0 shot injection method, and generally uses a mixed suspension of water glass, quick-setting admixture, cement, etc. It is mainly applied to the improvement of soft ground because it can be injected into both cohesive and sandy soil.

In the present invention, the equipment consists of a dedicated stirring device (mixer) capable of more than two stirrings, a pressure distribution device for supplying each stirring liquid in a fixed amount, a device for controlling the temperature of the combined water (boiler), and a double pipe rod. It may consist of a perforator for

For example, using a dedicated mixer that mixes agent A and agent B with water, respectively, a device (boiler) that allows the combined water to maintain a temperature of 20 to 30 ° C. In this case, the complex grout system can be applied by drilling with a perforator to the required depth.

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

Example

As a quick-setting composition (agent A), 52 parts by weight of amorphous calcium sulfoaluminate powder, 22 parts by weight of anhydrite powder, 18 parts by weight of desulfurized gypsum powder, and 8 parts by weight of a curing accelerator (sodium silicate) are mixed in 60 kg of a composition with 179.8 L of water (W/B = 300%) to prepare 200 L of solution A, 45 parts by weight of ordinary Portland cement as an inorganic composition (agent B), 25 parts by weight of blast furnace slag powder (about 5,000 cm2/g of powder), and paper 147.5 kg of water is mixed with 147.5 kg of composition (W /B = 300%) to prepare 200 L of solution B, and a grout composition was prepared by mixing solution A and solution B.

Comparative Example 1

A grout composition was prepared in the same manner as in Example except that 30 parts by weight of paper ash was used without using circulating fluidized bed boiler ash in the inorganic composition (agent B) in the above example.

Comparative Example 2

A grout composition was prepared in the same manner as in Example, except that 30 parts by weight of circulating fluidized bed boiler ash was used in the inorganic composition (agent B) in the above example without using paper ash.

test example

For the grout compositions prepared according to Examples and Comparative Examples, gel time and compressive strength by age were measured by the following method, and the results are shown in Table 1 below.

[Method for measuring gel time]

Gel time refers to the time it takes until the liquidity is lost and gelled as the viscosity gradually increases after mixing the A and B solutions. It is a measure to judge the constructibility of In this test example, 30 cc of each of solution A and solution B were weighed in a paper cup, and while stirring at intervals of about 1 second, the time for stopping the flow of the mixed solution was measured three times, and the average value was calculated.

[Method of measuring compressive strength by age]

In this test example, the compressive strength means the compressive strength of the solidified material obtained by hardening only the injection material mixed with solution A and solution B. According to the uniaxial compression test method of soil (KS F 2314), a cubic 50×50×50 mm size After the mold was manufactured and cured in water under the standard conditions of the mortar, the uniaxial compressive strength of three specimens was measured for each age of 3 days, 7 days and 28 days, and the average value was calculated.

division gel time
(sec) Compressive strength by age (MPa) 3 days 7 days 28 days Example 1 9 3.45 5.90 8.96 Comparative Example 1 18 1.38 2.57 4.12 Comparative Example 2 25 0.79 2.27 3.05

Referring to Table 1, in the ground injection reinforcement grout composition comprising the rapid setting composition and the inorganic composition according to the present invention, amorphous calcium sulfoaluminate powder, anhydrite powder and desulfurized gypsum powder are included as the rapid setting composition, and the inorganic composition Including furnace ordinary Portland cement, blast furnace slag powder, papermaking ash, and circulating fluidized bed boiler ash, but containing a certain amount of papermaking ash and circulating fluidized bed boiler ash, it contains a large amount of industrial by-products and high strength through hydration reaction control as well as realization of gel It can be seen that the time performance is improved.

In contrast, even when paper ash or circulating fluidized bed boiler ash is used alone in the same amount as the inorganic composition, the compressive strength and gel time performance are significantly reduced compared to the case of using the paper ash and circulating fluidized bed boiler ash in combination. .

As above, preferred embodiments of the present invention have been described in detail with reference to the drawings. The description of the present invention is for illustrative purposes, and those skilled in the art to which the present invention pertains will understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention.

Accordingly, the scope of the present invention is indicated by the claims described below rather than the above detailed description, and all changes or modifications derived from the meaning, scope, and equivalent concept of the claims are included in the scope of the present invention. should be interpreted

Claims (5)

A ground injection reinforcement grout composition comprising a quick-setting composition and an inorganic composition,
The quick-setting composition comprises amorphous calcium sulfoaluminate powder, anhydrite powder, desulfurized gypsum powder and a reactive agent,
The inorganic composition is a ground injection reinforcement grout composition comprising ordinary Portland cement, blast furnace slag powder, paper ash and circulating fluidized bed boiler ash. The method of claim 1,
The rapid setting composition comprises 37 to 67% by weight of the amorphous calcium sulfoaluminate powder, 12 to 32% by weight of the anhydrite powder, 10 to 25% by weight of the desulfurized gypsum powder, and 2 to 15% by weight of the reactant,
The inorganic composition comprises 30 to 60% by weight of the ordinary Portland cement, 15 to 35% by weight of the blast furnace slag powder, 5 to 25% by weight of the papermaking ash, and 5 to 25% by weight of the circulating fluidized bed boiler ash,
Ground injection reinforcement grout composition, characterized in that the weight ratio of the quick-setting composition and the inorganic composition is 1:1 to 1:5. 3. The method of claim 2,
The paper ash contains at least 55 wt% of calcium oxide (CaO) and at least 10 wt% of silicon dioxide (SiO ₂ ), and the circulating fluidized bed boiler ash contains at least 45 wt% of calcium oxide (CaO) and silicon dioxide (SiO) ₂ ) Ground injection reinforcement grout composition, characterized in that it contains 8% by weight or more. As a ground injection reinforcement construction method using a grout composition,
The liquid A containing the quick-setting composition of claim 1 and the liquid B containing the inorganic composition of claim 1 are each sent at the same pressure through a separate pump at the same pressure, and the heterogeneous solution is supplied in a mixed state in the injection tube connected to the Y tube, , A ground injection reinforcement construction method using a 1.5-shot type grout composition performed by spraying a filler into the ground through a through hole formed in the lower part. As a ground injection reinforcement construction method using a grout composition,
The ground injection reinforcement construction using the 2.0-shot type grout composition, which is performed by sending the liquid A containing the quick-setting composition of claim 1 and the liquid B containing the inorganic composition of claim 1 to the underground through a double injection pipe and mixing them in the underground method.