KR102021116B1 - Moltal agent and compaction grouting method thereby - Google Patents

Abstract

The present invention relates to: a dry mortar composition for a consolidation grouting method which allows a bottom ash discharged from the bottom of a circulating fluidized bed boiler, which is a low utilization industrial by-product, to simultaneously play the role of a stimulator and aggregate of a blast furnace slag micropowder, thereby replacing raw materials that must be obtained by damaging natural resources with circulating resources; and the consolidation grouting method using the same. The dry mortar composition for the consolidation grouting method according to the present invention, based on 100 parts by weight of a circulating fluidized bed boiler bottom ash adjusted to have a particle size of 0.01 to 5 mm, contains 5 to 100 parts by weight of the blast furnace slag micropowder and 1 to 30 parts by weight of cement.

Description

Dry mortar composition for consolidation grouting method and consolidation grouting method using same {MOLTAL AGENT AND COMPACTION GROUTING METHOD THEREBY}

The present invention provides a slump in a grouting method for reinforcing a soft ground or preventing a settlement of a structure on a soft ground, or for reinforcing a foundation to ensure safety of ground and underground structures and installations that have already been settled and threatened to safety. The present invention relates to a dry mortar composition for the compaction grouting method using a low-low flow mortar as an injection material, and to a compaction grouting method using the same. More specifically, the bottom ash discharged from the bottom of the circulating fluidized bed boiler is used as a stimulant of blast furnace slag fine powder. The present invention relates to a dry mortar composition for the consolidation grouting method which can replace raw materials that should be obtained by damaging natural resources by using aggregates, and to facilitate quality control in the field, and a consolidation grouting method using the same.

In general, grouting works to improve soft ground by filling materials include chemical liquid injection methods for injecting cement milk and chemicals, on-site casting aggregate pile methods for buying aggregates such as gravel into excavation ground, and consolidation grouting for filling mortar with low slump. (Compaction Grouting) There is a trend that the consolidation grouting method, which is considered to best withstand the vertical and horizontal pressures and dynamic loads, is being applied to many sites.

The consolidation grouting method is a method of drawing low-flowing mortar using a high-pressure pump immediately after digging a hole to a predetermined depth using a drilling machine, and using one type cement as a binder in a soft ground, and using Masato and aggregate as aggregate. It is a method of filling low-flow mortar mixed with water by using stone powder.

However, in the case of the cement is a product manufactured by using limestone, clay, iron ore as a raw material and pyrolysis at a high temperature of 1,450 ℃ using imported bituminous coal as a fuel, it generates a large amount of carbon dioxide in the manufacturing process, and consumes a limited amount of natural resources. It has a problem that is not environmentally friendly.

In addition, stone flour used as fine aggregate and masato used as fine aggregate among the aggregates is artificially manufactured aggregates by damaging natural resources, which is not environmentally friendly, and when there is no aggregate source near the soft ground improvement site, it is difficult to obtain raw materials. .

In addition, since the low flow mortar consolidation injection material must be manufactured to faithfully express the ground reinforcement effect with a predetermined viscosity and strength, the constituent material must be quantitatively measured and injected in the field.

However, it is difficult to put the mass and stone powder in the unpacked state by using a dump truck, so it is difficult to put it in the correct weight, and it is difficult to control the fluidity when mixing in the field because the materials are brought in a heterogeneous wet state. .

Patent Application No. 10-2010-57366 Patent Application No. 10-2010-33929

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a bottom ash discharged from the bottom of a circulating fluidized bed boiler, which is a low utilization industrial by-product, to simultaneously serve as a stimulant and aggregate of blast furnace slag fine powder. It is to provide a dry mortar composition for the consolidation grouting method and a consolidation grouting method using the same that can replace the raw materials that must be obtained by damaging resources with circulating resources.

Dry mortar composition for the consolidation grouting method according to the present invention in order to solve the above technical problem is 5 to 100 parts by weight of blast furnace slag fine powder with respect to 100 parts by weight of the circulating fluidized bed boiler bottom ash adjusted to have a particle size of 0.01 to 15mm And 1 to 30 parts by weight of cement.

The pulverized coal boiler bottom ash may further include 5 to 500 parts by weight of the particle size adjusted to have a particle size of 0.01 to 15 mm based on 100 parts by weight of the circulating fluidized bed boiler bottom ash.

The circulating fluidized bed boiler bottom ash may further comprise 1 to 30 parts by weight of the circulating fluidized bed boiler fly ash.

In addition, with respect to 100 parts by weight of the circulating fluidized bed boiler bottom ash, further comprising 1 to 200 parts by weight of incineration, wherein the incineration material is any one or two or more selected from sewage sludge incineration, paper sludge incineration, dyeing wastewater sludge incineration and waste vinyl incineration. It is preferred that it is a mixture.

Consolidation grouting method according to the present invention comprises the steps of 1) preparing a dry mortar according to any one of claims 1 to 4; 2) adding water to the mortar and mixing to prepare a wet mortar; 3) injecting the injection tube into the ground; And 4) injecting the wet mortar into the ground through an injection tube with an injection pump to form bulbs.

According to the present invention, there is an effect that a large amount of circulating fluidized bed boiler bottom ash, which is insufficiently utilized, can be utilized as a stimulant and aggregate of blast furnace slag fine powder.

Therefore, in the manufacture of conventional consolidation grouting mortar, as a binder, one type of Portland cement and aggregate, Masato and stone powder are mixed with water in the field, whereas the present invention uses the bottom ash discharged from the bottom of the circulating fluidized bed boiler to stimulate blast furnace slag fine powder and By having a simultaneous role as aggregate, it is possible to replace raw materials that have to be obtained by damaging natural resources with circulating resources.

In addition, the dry mortar for the consolidation grouting method according to the present invention is delivered to the site in the form of dry packaging has the advantage of easy quality control because only water can be used in the field.

Hereinafter, the dry mortar composition for the consolidation grouting method and the consolidation grouting method using the same according to the present invention will be described in detail.

The dry mortar composition for the consolidation grouting method according to the present invention includes 5 to 300 parts by weight of blast furnace slag fine powder and 1 to 100 parts by weight of cement based on 100 parts by weight of the circulating fluidized bed boiler bottom ash adjusted to have a particle size of 0.01 to 10 mm. It features. The cement includes a known cement such as Portland or blast furnace slag cement.

The circulating fluidized bed boiler bottom ash is a circulating fluidized bed for burning any one or two or more mixtures selected from the group consisting of coal, solid solid fuel (SRF, Solid Refuse Fuel), bio solid fuel (BIO-SRF, Biomass-Solid Refuse Fuel) Exhaust from the bottom of the boiler.

In the desulfurization process of the circulating fluidized bed boiler, limestone is injected into the combustion chamber and combusted with fuel to react sulfur phosphate and limestone in the combustion gas in the furnace to remove sulfur in the combustion gas and to produce anhydrous gypsum. It is carbonated, transferred to quicklime components, and discharged.

In particular, the circulating fluidized bed boiler bottom ash is combusted at a temperature of about 850 ° C. and thus can not cause a pozzolanic reaction because there is no vitreous component, but contains higher CaO and CaSO ₄ components than fly ash collected at the top.

Therefore, because the quicklime component of the circulating fluidized bed boiler bottom ash causes expansion when reacted with water, shrinkage can be prevented as compared with the case of using only one type of cement, thereby minimizing the gap between the perforated hole and the mortar. In addition, the anhydrous gypsum component may act as a sulfate stimulator of the blast furnace slag powder to form calcium silicate and ettringite hydrate to express strength.

In addition, the particle size of the circulating fluidized bed boiler bottom ash can play the role of aggregate at the same time as the size of the sand can perform a function that can replace the masato or stone powder used in the conventional consolidation grouting method. The circulating fluidized bed boiler bottom ash is more preferably adjusted to have a particle size of 0.01 to 5 mm.

Therefore, in the present invention, the circulating fluidized bed boiler bottom ash can play a simultaneous role as a stimulant and aggregate of blast furnace slag fine powder.

The blast furnace slag fine powder is a product manufactured according to the Korean Industrial Standards (KS), and uses a commercially available product. The blast furnace slag fine powder is preferably contained 5 to 300 parts by weight based on 100 parts by weight of the circulating fluidized bed boiler bottom ash. If it is less than 5 parts by weight, the predetermined strength cannot be expressed, and even when incorporated in excess of 300 parts by weight, the required amount of the circulating fluidized bed boiler bottom ash for alkali and sulphate complex stimulation is insufficient, so that the required strength is not expressed.

The cement may be used a general product in the market to increase the initial strength. The cement is preferably contained 1 to 100 parts by weight based on 100 parts by weight of the circulating fluidized bed boiler bottom ash. If it is less than 1 part by weight, the initial strength may not be expressed, and if it is mixed in excess of 100 parts by weight, economical efficiency may be unreasonable, and hexavalent chromium may be eluted.

In addition, it is preferable to further include 5 to 500 parts by weight of pulverized coal boiler bottom ash having a particle size of 0.01 to 15 mm with respect to 100 parts by weight of the circulating fluidized bed boiler bottom ash. Pulverized coal boiler bottom ash is discharged from most thermal power plants in Korea with a separate desulfurization device. Pulverized coal boiler bottom ash has a considerably larger particle size than fly ash due to the characteristics of the ash-melt-aggregated process at high temperature. However, it is difficult to recycle them, so each power station is making a very large pond and filling it.

However, pulverized coal boiler bottom ash is also silicon dioxide whose main component can cause pozzolanic reaction like pulverized coal boiler fly ash, which is mainly used in ready mixed concrete, and it is a stable material with various particle diameters of 0.01 ~ 50mm. . Pulverized coal boiler bottom ash plays the role of coarse aggregate when the assembly of circulating fluidized bed boiler bottom ash is relatively insufficient, and can replace the role of stone powder used as coarse aggregate in the existing consolidation method.

Pulverized coal boiler bottom ash has a maximum particle diameter of about 50mm thick coarse particles exist so that the maximum particle diameter must be adjusted to 15mm or less to prevent clogging of the injection pipe during consolidation grouting construction. In addition, the pulverized coal boiler bottom ash preferably further includes 5 to 500 parts by weight based on 100 parts by weight of the circulating fluidized bed boiler bottom ash. If it is less than 5 parts by weight, it cannot serve as a coarse aggregate. If it is mixed in excess of 500 parts by weight, the amount of circulating fluidized bed boiler bottom ash, which serves as a fine aggregate, is relatively reduced, resulting in insufficient mortar viscosity and material separation. Can be.

The circulating fluidized bed boiler bottom ash may further include 1 to 200 parts by weight of the circulating fluidized bed boiler fly ash. The circulating fluidized bed boiler fly ash has a SiO ₂ content of 10 to 45% by weight, a CaO content of 10 to 55% by weight, and a SO ₃ content of 3 to 20% by weight, and is preferably discharged from the circulating fluidized bed boiler dust collector. The circulating fluidized bed boiler fly ash is discharged from a power plant having an in-furnace desulfurization facility. Since limestone is mixed and combusted with coal and other auxiliary fuels, a high alkali material having a high CaO content and SO ₃ content of pH 11.5 or higher during decarburization and desulfurization of limestone It acts as a stimulant and expander for blast furnace slag.

The circulating fluidized bed boiler fly ash preferably further includes 1 to 200 parts by weight based on 100 parts by weight of the circulating fluidized bed boiler bottom ash. If it is less than 1 part by weight, the effect is not exerted, and if it exceeds 200 parts by weight, the fluidity is drastically reduced.

In addition, it is preferable to further include 1 to 30 parts by weight of the incineration ash with respect to 100 parts by weight of the circulating fluidized bed boiler bottom ash, wherein the incineration ash is any one or two of sewage sludge incineration, paper sludge incineration, dyeing wastewater sludge incineration, waste vinyl incineration. It is a mixture of the above.

The incineration ash may inhibit material separation by acting to increase the amount of excess water adsorption and viscosity present in the mortar. The incineration ash may further include 1 to 200 parts by weight based on 100 parts by weight of the circulating fluidized bed boiler bottom ash. If it is less than 1 part by weight, the effect is not exerted, and if it exceeds 200 parts by weight, excessive moisture adsorption and viscosity become strong, and workability (workability) is drastically lowered.

Hereinafter, the steps of the process according to the present invention will be described.

1) preparing a dry mortar for the consolidated grouting method in the above manner; 2) preparing a wet mortar by adding water to the dry mortar for the consolidation grouting method, followed by mixing; 3) injecting the injection tube into the ground; And 4) injecting the wet mortar into the ground through an injection tube with an injection pump to form bulbs.

In the step 1), the raw materials are mixed in a factory to produce a product in the form of dry mortar, and are supplied to the site as a packing unit in a zone, ton bag or bulk form. In step 2), water is added to the dry mortar manufactured and supplied by the factory, followed by mixing to prepare a wet mortar. Therefore, as in the conventional method, it is not necessary to separately mix masato and stone powder as aggregates in the field, and it is possible to use the water after injecting only in the field, so that the air shortening and quality control may be easy.

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.

Comparative example

First, 50 parts by weight of stone powder having a particle size distribution of 1.5 mm to 10 mm as a coarse aggregate is composed of 50 parts by weight of clay silt soil having a particle size distribution of 0.02 mm to 1.5 mm as fine aggregate according to the standard specification of consolidation grouting method. 30 parts by weight of Portland cement and 12 parts by weight of water were homogeneously mixed with a forced mixer with respect to 100 parts by weight of the aggregate to prepare a mortar mixture.

Next, the slump test was carried out using the prepared samples, and the compressive strength for each age was measured by preparing a specimen for measuring the compressive strength.

Example 1

First, 20 parts by weight of blast furnace slag fine powder and 10 parts by weight of one Portland cement are homogeneously mixed with a powder ribbon mixer with respect to 100 parts by weight of a circulating fluidized bed boiler bottom ash having a particle size distribution of 0.01 mm to 5 mm as aggregate. Prepared.

12 parts by weight of water was mixed with the dry mortar mixture to prepare a wet mortar by mixing with a forced mixer. Next, a slump test was performed using the prepared sample, and a compressive strength for each age was produced by preparing a specimen for measuring compressive strength. Was measured.

Example 2

First, 50 parts by weight of a pulverized coal boiler bottom ash having a particle size distribution of 1 mm to 15 mm as a coarse aggregate is composed of 50 parts by weight of a circulating fluidized bed boiler bottom ash having a particle size distribution of 0.02 mm to 5 mm as fine aggregate, and the aggregate 100 A dry mortar mixture was prepared by homogeneously mixing 20 parts by weight of blast furnace slag powder, 5 parts by weight of a Portland cement, and 5 parts by weight of a circulating fluidized bed boiler fly ash with a powder ribbon mixer.

12 parts by weight of water was mixed with the dry mortar mixture to prepare a wet mortar by mixing with a forced mixer. Next, a slump test was performed using the prepared sample, and a compressive strength for each age was produced by preparing a specimen for measuring compressive strength. Was measured.

Example 3

First, 20 parts by weight of blast furnace slag fine powder, 5 parts by weight of one type Portland cement, and 5 parts by weight of sewage sludge incineration were homogenized with a powder ribbon mixer with respect to 100 parts by weight of the circulating fluidized bed boiler bottom ash having a particle size distribution of 0.01 mm to 10 mm as aggregate. Mixed to form a dry mortar mixture.

12 parts by weight of water was mixed with the dry mortar mixture to prepare a wet mortar by mixing with a forced mixer. Next, a slump test was performed using the prepared sample, and a compressive strength for each age was produced by preparing a specimen for measuring compressive strength. Was measured.

Performance test method and result of injection mortar for consolidation grouting method

As shown in Table 1 below, the slump test was conducted by KS F 2402 (concrete slump test method), and the compressive strength test was performed by KS F 2405 (concrete compressive test method).

Experiment Way designation Slump flow KS F 2402 Slump test method of concrete Compressive strength KS F 2405 Test method for compressive strength of concrete Material separation Visual inspection Volume change Visual inspection

(1) slump test result

Table 2 shows the results of measuring the slump of the examples and the comparative examples. The slump of the mortar composition of the Example was high although the weight of the unit binder, the blending water, and the aggregate of the Example and Comparative Example were the same. This means that the unit quantity can be reduced in order to produce the same slump, and thus, when the circulating fluidized bed boiler bottom ash is used, it is effective in improving the strength and reducing the shrinkage compared to the masato and stone powder used in the conventional method.

In the case of Example 2 using the pulverized coal boiler bottom ash in the circulating fluidized bed boiler bottom ash, the slump is slightly higher than that of Example 1, and the use of the pulverized coal boiler bottom ash is more effective in improving the fluidity. In Example 3 using the sewage sludge incineration material, although the slump was slightly reduced, it was confirmed that the viscosity became stronger and the resistance to material separation was improved.

Slump and compressive strength measurement results division Slump (mm) Compressive strength (MPa) 3 days of age 7 days of age 28 days of age Comparative example 45 10.7 17.3 22.9 Example 1 65 13.3 21.8 27.2 Example 2 70 11.3 21.1 28.2 Example 3 50 10.9 20.3 25.6

(2) Test results of uniaxial compressive strength

Table 2 shows the results of the uniaxial compressive strength of the Examples and Comparative Examples.

As shown in Table 2, in the case of Examples 1, 2, and 3, both the initial and long-term strengths were expressed higher than those of the comparative example, which is not only a simple aggregate but also reacts with fine blast furnace slag powder as a latent hydraulic material. This means that the hydrate was produced to express strength.

(3) other

In both the examples and the comparative examples, material separation did not occur after mixing the mortar, thereby ensuring the field workability, and the result of visual observation of the volume change before capping by producing a compressive strength specimen, In the embodiment, the volume was increased even though the shrinkage was compensated by the expandability, but the comparative example was visually confirmed that the volume shrinkage occurred.

Claims (5)

1) preparing dry mortar;
2) preparing a wet mortar by adding water to the dry mortar and mixing the mixture;
3) injecting the injection tube into the ground; And
4) injecting the wet mortar into the ground through an injection tube with an injection pump to form a bulb;
Step 1),
Per 100 parts by weight of the circulating fluidized bed boiler bottom ash,
Blast furnace slag fine powder 5-100 parts by weight,
1 to 30 parts by weight of cement,
To dry the mortar by mixing 1 to 200 parts by weight of the incineration ash to increase the viscosity to suppress material separation,
The circulating fluidized bed boiler bottom ash is a circulating fluidized bed for burning any one or two or more mixtures selected from the group consisting of coal, solid solid fuel (SRF, Solid Refuse Fuel), bio solid fuel (BIO-SRF, Biomass-Solid Refuse Fuel) Discharged from the bottom of the boiler,
The circulating fluidized bed boiler bottom ash is mixed with alkali and sulfate stimulation of the blast furnace slag fine powder and adjusted to have a particle size of 0.01 to 5 mm to act as aggregate,
The incineration ash is a consolidation grouting method, characterized in that any one or a mixture of two or more selected from sewage sludge incineration, dyeing wastewater sludge incineration and waste vinyl incineration.
The method of claim 1,
Step 1),
Consolidation grouting method of producing a dry mortar by further mixing 5 to 500 parts by weight of pulverized coal boiler bottom ash adjusted to have a particle size of 0.01 to 15mm with respect to 100 parts by weight of the circulating fluidized bed boiler bottom ash.
The method of claim 1,
Step 1),
Consolidation grouting method, characterized in that for producing the dry mortar by further mixing 1 to 30 parts by weight of the circulating fluidized bed boiler fly ash with respect to 100 parts by weight of the circulating fluidized bed boiler bottom ash.
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