KR102561131B1 - Binder Composition for Segment Concrete of Underground Structure and Concrete Using the Same - Google Patents

Abstract

The present invention relates to segment manufacturing technology for use in the construction of underground structures such as continuous excavation tunnel construction, and to high-strength binder compositions for segments and high-strength watertight concrete.
The high-strength binder composition for segments according to the present invention includes 70 to 80% by weight of fine blast furnace slag powder with a fineness of 6,000 ± 500 cm ² /g; 5 to 15% by weight of natural anhydrous gypsum bitter powder measuring 4,500±500 cm ² /g; Type 1 ordinary Portland cement 5 to 15% by weight; Supercritical fluidized bed boiler fly ash 5-10% by weight; 2 to 5% by weight of silica fume; It is characterized in that it is composed of 2 to 5% by weight of CSA-based expansion material. Here, the blast furnace slag fine powder and natural anhydrous gypsum fine powder can be preferably applied as three types of blast furnace slag fine powder and natural anhydrous gypsum powder mixed by grinding with a grinding aid added and treated into a bitter powder. High-strength watertight concrete according to the present invention, in concrete mixing, based on 100 parts by weight of high-strength binder for segments, 0.1 to 0.5 parts by weight of sodium nitrate, 0.1 to 0.5 parts by weight of sodium sulfate, 0.1 to 1.0 parts by weight of stearic acid, and supercritical fluidized bed boiler fly. 0.1 to 1.0 parts by weight of ash is mixed and mixed, and the sodium nitrate, sodium sulfate, stearic acid, and supercritical fluidized bed boiler fly ash are characterized in that they are ground and mixed with a grinding aid added.

Description

High-strength binder composition for continuous excavation segments of underground structures and high-strength watertight concrete for continuous excavation segments using the same {Binder Composition for Segment Concrete of Underground Structure and Concrete Using the Same}

The present invention relates to a technology for manufacturing continuous excavation segments of underground structures for use in continuous excavation tunnel construction, etc. More specifically, the material for use in segment production has excellent physical properties such as strength and water tightness, while securing economic efficiency by reducing the amount of cement used. It relates to a high-strength binder composition for continuous excavation segments that can be used, and to high-strength watertight concrete in which strength and watertightness are further improved by appropriately using additives while preferably using such high-strength binder for continuous excavation segments.

As underground space development becomes more active, the construction of concrete underground structures is also increasing. The TBM method is a construction method for underground structures such as tunnels. The TBM (Tunnel Boring Machine) method is a method of digging a tunnel by rotating the cutterhead on the front of the excavator and assembling pre-fabricated tunnel wall segments. The TBM method excavates with a circular cross-section, so unlike conventional construction that involves repeated drilling and blasting, it is characterized by mechanically stable vibration-free, non-blasting, and mechanized excavation. Recently, a continuous excavation type TBM method was developed to continuously install spiral-shaped segments without stopping the TBM because the TBM excavation propulsion jack does not interfere with the segment installation work. The continuous excavation TBM method has the advantage of reducing costs by shortening the construction period as there is no interruption in excavation and also making excavation management easier.

In the continuous excavation type TBM method, segments are made of high-strength and high-durability concrete. If the segment material has high strength and high durability, the maintenance demand for the tunnel is reduced and the fundamental safety of the structure can be secured. Since concrete for segments is installed underground, the material itself must be able to respond to water leaks and cracks, and must be able to ensure safety even in disasters such as fire.

In Korea, segment concrete applied to the TBM method is produced with a target strength of 30 to 45 MPa, and high-strength reinforcing bars of SD400 to SD600 are used according to the design standards for concrete. The application of high-strength rebar increases the cross-section of concrete. The increase in the cross-section of concrete leads to an increase in the amount of concrete used, and the increase in the amount of concrete used leads to an increase in costs, so it is necessary to prepare countermeasures.

Meanwhile, when a crack occurs in a concrete underground structure, groundwater leaks from the point where the crack occurred, greatly reducing the durability of the concrete. When sulfate (SO ₃ component) from groundwater penetrates into concrete, it reacts with C ₃ A in cement to produce an expansive (2 to 3.5 times expanded) hydrate (Ettringite, C ₃ A·3CaSO ₄ ·32H ₂ O). As the concrete expands and fractures due to the product, its durability decreases. Deterioration in the durability of concrete may lead to problems such as explosion of concrete and destruction of members in the event of a fire. In addition, when concrete loses alkalinity or the chloride concentration reaches a critical value due to penetration and diffusion, the passivity film, which is the protective film of the reinforcing bar, is destroyed. In this case, the reinforcing bar inside the concrete member is exposed to the corrosive environment and corrodes. When reinforcing bars corrode, not only does the cross-sectional area and mechanical performance of concrete deteriorate, but cracks occur in the concrete due to the expansion of reinforcing steel corrosion by-products.

In order to control the occurrence of cracks in concrete, it is necessary to control cracks in early-aged concrete that occur during the construction stage. This is because cracks that occur at an early age, even if they are microcracks, have a fatal impact on the durability of concrete structures by promoting water leakage, neutralization, and corrosion of reinforcing bars. Drying shrinkage of concrete that occurs at an early age causes microscopic cracks on the concrete surface. These microcracks do not immediately weaken the safety performance of concrete, but they accelerate the intrusion of various harmful factors from the external environment into the concrete, reducing the water resistance of the structure. greatly reduces it.

KR 10-1794960 B1 KR 10-2013-0116979 A

The present invention was developed to improve the physical performance of segments used in the construction of underground structures by methods such as the continuous excavation TBM method. It is for segments that have excellent physical properties such as strength and watertightness and can secure economic feasibility by reducing the amount of cement used. There is a technical challenge in providing a high-strength binder composition and a high-strength watertight concrete composition for segments using the same preferably.

In order to solve the above-described technical problem, the present invention includes 70 to 80% by weight of fine blast furnace slag powder with a fineness of 6,000 ± 500 cm ² /g; 5 to 15% by weight of natural anhydrous gypsum bitter powder measuring 4,500±500 cm ² /g; Type 1 ordinary Portland cement 5-15% by weight; Supercritical fluidized bed boiler fly ash 5-10% by weight; 2 to 5% by weight of silica fume; Provided is a high-strength binder composition for segments, characterized in that it consists of 2 to 5% by weight of a CSA-based expansion material. Here, the blast furnace slag fine powder and natural anhydrous gypsum fine powder can be preferably applied as three types of blast furnace slag fine powder and natural anhydrous gypsum powder, respectively, which are pulverized with a grinding aid added and treated into a bitter powder.

In addition, the present invention relates to concrete mixing using a high-strength binder composition for segments, based on 100 parts by weight of binder, 0.1 to 0.5 parts by weight of sodium nitrate, 0.1 to 0.5 parts by weight of sodium sulfate, 0.1 to 1.0 parts by weight of stearic acid, and supercritical fluidized bed boiler fly ash. 0.1 to 1.0 parts by weight are mixed and mixed, and the sodium nitrate, sodium sulfate, stearic acid, and supercritical fluidized bed boiler fly ash are ground and mixed with a grinding aid added. A high-strength watertight concrete composition for segments is provided.

According to the present invention, the following effects can be expected.

First, the concrete mix using the binder for segments of the present invention exhibits high strength and watertightness, and in particular, by incorporating appropriate additives, not only strength but also watertightness can be further improved. As a result, the concrete of the present invention can be advantageously used in the production of continuous excavation type segments.

Second, instead of reducing the amount of cement used in the concrete mix for segment production, it actively uses blast furnace slag fine powder and supercritical fluidized bed boiler ash, which are industrial by-products, contributing to carbon reduction.

The present invention relates to segment manufacturing technology for use in the construction of underground structures such as continuous excavation tunnel construction, and relates to high-strength binders for segments and high-strength watertight concrete. The present invention can be preferably applied to tunnel construction constructed using the continuous excavation TBM method, and can also be applied to other construction methods and other types of underground structure construction.

1. High-strength binder for segments

The high-strength binder for segments according to the present invention includes 70 to 80% by weight of fine blast furnace slag powder with a fineness of 6,000 ± 500 cm ² /g; 5 to 15% by weight of natural anhydrous gypsum bitter powder measuring 4,500±500 cm ² /g; Type 1 ordinary Portland cement 5-15% by weight; Supercritical fluidized bed boiler fly ash 5-10% by weight; 2 to 5% by weight of silica fume; It is characterized in that it is composed of 2 to 5% by weight of CSA-based expansion material. By using a large amount of 3 types of blast furnace slag fine powder, we are reducing the amount of type 1 ordinary Portland cement, and by appropriately using supercritical fluidized bed boiler fly ash, natural anhydrous gypsum, silica fume, and CSA expansion materials, we are trying to secure excellent physical properties for segmentation. It was done.

Blast furnace slag fine powder is made by quenching molten blast furnace slag, which is produced at the same time as pig iron in a blast furnace, with water and pulverizing it, and is the main material for a binder that replaces cement. Since blast furnace slag fine powder contains CaO, SiO ₂ , and Al ₂ O ₃ as main ingredients, it helps in the creation of ettringite and thus contributes to increased strength. In addition, it produces a product that fixes chloride ions (Friedel's salt, 3CaO·Al ₂ Because it easily generates O ₃ ·CaCl ₂ ·10H ₂ 0), it plays a major role in suppressing the penetration and diffusion of chloride ions. In particular, in the present invention, a fine blast furnace slag powder with a fineness of 6,000 ± 500 cm ² /g is used to secure physical and durable performance by increasing reactivity with cement and increasing the water tightness of the internal pores of concrete. Blast furnace slag fine powder can be prepared by grinding three types of blast furnace slag fine powder (specific gravity 2.80~2.90, fineness 4,500±500cm ² /g) with a grinding aid added. At this time, glycerin can be preferably used as a grinding aid, and glycerin reduces the phenomenon of secondary particles being created by coatings or fine particles attached to the grinding medium (steel balls and liners) and the phenomenon of fine particles adhering to coarse particles, making grinding and grinding easier. It improves production performance and contributes to energy savings. Blast furnace slag fine powder is used in an amount of 70 to 80% by weight. If it is less than 70% by weight, the amount of cement increases relatively, resulting in loss of economic feasibility, lack of carbon reduction effect, and lack of effect in resisting the penetration and diffusion of chloride ions, and exceeding 80% by weight. If this is done, there are concerns about lack of early and long-term strength development.

Natural anhydrous gypsum fine powder contributes to strength improvement by activating the hydration reaction of blast furnace slag fine powder and ordinary Botland cement, and also plays a role in controlling the setting time by preventing rapid setting of C ₃ A in ordinary Portland cement. In particular, in the present invention, natural anhydrous gypsum fine powder having a powder size of 4,500 ± 500 cm ² /g is used to increase reactivity and watertightness like the blast furnace slag fine powder. Natural anhydrous gypsum is used in the binder in an amount of 5 to 15% by weight. If it is less than 5% by weight, it has low activity and it is difficult to achieve physical performance, and if it exceeds 15% by weight, the strength improvement effect is minimal and economic feasibility is lost. Like the blast furnace slag bitter powder, natural anhydrous gypsum bitter powder can be prepared by grinding regular natural anhydrous gypsum powder (specific gravity 2.90-3.00, fineness 3,500 ± 500 m ² /g) with a grinding aid added.

In the binder, 5 to 15% by weight of Portland cement is usually used, and this is to promote economic efficiency by using small amounts. If it is less than 5% by weight, strength development is insufficient, and if it exceeds 15% by weight, it results in loss of economic feasibility and lack of carbon reduction effect.

Supercritical fluidized bed boiler fly ash is ash discharged from a supercritical fluidized bed boiler through the process of burning coal fuel under supercritical conditions while injecting oxygen, and contains 10-20% by weight of Fe ₂ O ₃ and 5-20% by weight of SO ₃ It has the characteristic of having a fineness of 6,000 to 9,000 m ² /g. This supercritical fluidized bed boiler fly ash has a higher fineness than general chemical power plant fly ash, contributing to improved water tightness and early strength, and also plays a role in stimulating the reactivity of blast furnace slag fine powder. It is desirable to use 5 to 10% by weight of supercritical fluidized bed boiler fly ash in the binder. If it is less than 5% by weight, the strength improvement effect is minimal, and if it exceeds 10% by weight, there is concern about a decrease in workability due to decreased fluidity and a decrease in strength. I'm concerned.

Silica fume is an industrial by-product of ultra-fine particles obtained by collecting SiO ₂ contained in waste gas generated when manufacturing silicon, ferrosilicon, silicon alloy, etc. with a dust collector. It is characterized by a specific gravity of 2.20 to 2.25 and a fineness of more than 130,000 m ² /g. am. Silica fume contributes to the development of high strength due to its high specific surface area, and also contributes to the development of durability such as water tightness and water permeability because it densifies the tissue while exhibiting a void filling effect through a pozzolanic reaction in the early stage of hydration. Silica fume is used in the binder in an amount of 2 to 5% by weight. If it is less than 2% by weight, it improves strength. When added in a small amount, the effect of improving strength and durability is minimal. If it exceeds 5% by weight, there is a risk of cracking due to plastic shrinkage.

When CSA-based expansion materials are mixed with cement and water, they form ettringite (C3A·3CaSO4·32H2O), monosulfate (C3A·CaSO4·12H2O), and calcium hydroxide (Ca(OH)2) through a hydration reaction. It becomes a material that expands as it is created and fills micropores, thereby contributing to improving durability by reducing drying shrinkage of concrete. CSA-based expansion material is used in the binder in an amount of 2 to 5% by weight. If it is less than 2% by weight, the expansion effect is minimal, and if it exceeds 5% by weight, the self-shrinkage reduction effect is reduced and economic feasibility is lost.

2. High-strength watertight concrete for segments

The high-strength watertight concrete for segments according to the present invention is a high-strength watertight concrete mix using a high-strength binder for segments, and contains 0.1 to 0.5 parts by weight of sodium nitrate, 0.1 to 0.5 parts by weight of sodium sulfate, and 0.1 to 1.0 parts by weight of stearic acid, based on 100 parts by weight of binder. , the supercritical fluidized bed boiler is characterized in that 0.1 to 1.0 parts by weight of fly ash is mixed as an additive. Here, the additive can be prepared by grinding and mixing through the process shown in FIG. 2. Sodium nitrate, sodium sulfate, stearic acid, and supercritical fluidized bed boiler fly ash were milled and mixed with a grinding aid added to ensure uniform dispersion. Glycerin can be preferably used as a grinding aid.

Sodium nitrate and sodium sulfate play a role in promoting the cement hydration reaction by increasing the pH of Na+ ions and at the same time serve as fillers that allow the concrete composition to be evenly mixed. In addition, the NO ₃ ^- ions of sodium nitrate (NaNO ₃ ) contribute to ensuring usability at low temperatures by lowering the condensation temperature of the mixed water, and the SO ₄ ^{2 -} ions of sodium sulfate contribute to enhancing strength by creating a smooth environment for the formation of Ettringite. . Sodium nitrate is used in an amount of 0.1 to 0.5 parts by weight per 100 parts by weight of the binder. If it is less than 0.1 part by weight, the effect of use is minimal, and if it exceeds 0.5 parts by weight, there are concerns about reduced fluidity and loss of economic feasibility. Sodium sulfate is also used in an amount of 0.1 to 0.5 parts by weight per 100 parts by weight of binder.

Stearic acid causes chemical reactions with SO ₄ ^2- , Cl ^- , Mg ²⁺ , Na ⁺ , etc., preventing the expansion of reinforcing bars in concrete and contributing to improving the durability of concrete by blocking moisture infiltration. It also fills the voids inside the concrete, improving the quality of the concrete. It also contributes to improving watertightness. It is preferable to use 0.1 to 1.0 parts by weight of stearic acid per 100 parts by weight of the binder.

Supercritical fluidized bed boiler fly ash contributes to improving strength and watertightness, while also serving as a material for even dispersion of sodium nitrate, sodium sulfate, and stearic acid. As an additive, 0.1 to 1.0 parts by weight of supercritical fluidized bed boiler fly ash is sufficient for 100 parts by weight of binder.

Hereinafter, the present invention will be examined in detail based on manufacturing examples and test examples. However, the following manufacturing examples and test examples are only for illustrating the present invention, and the scope of the present invention is not limited thereto.

[Preparation Example 1] Preparation of bitter powder

3 types of blast furnace slag fine powder (specific gravity 2.80~2.90, fineness 4,500±500cm ² /g) and general natural anhydrous gypsum (specific gravity 2.90~3.00, fineness 3,500±500cm ² /g), blast furnace slag fine powder and natural anhydrous gypsum Manufactured from bitter powder. Specifically, 10 to 20% of the weight of the alumina ball mill was filled with three types of blast furnace slag powder in an alumina ball mill that can accommodate up to 5 kg, and then ceramic balls (5.0 mm, 10.0 mm, 30.0 mm) were added in equal quantities to give the alumina ball mill a weight of 5 kg. About ~10% was added, and 1.0-1.5% of liquid glycerin was added as a grinding aid based on the weight of the binder, and grinding was performed while maintaining 150-200 RPM for 18-48 hours. By sieving the pulverized sample through a 0.075 mm sieve, it was possible to secure a fine blast furnace slag powder with a fineness of 6,000 ± 500 cm ² /g. Natural anhydrous gypsum powder was also pulverized in the same manner to obtain a fine natural anhydrous gypsum powder with a fineness of 4,500 ± 500 cm ² /g.

[Test Example 1] Characteristics of segment concrete according to type of binder

1. Manufacturing segment test specimens

The segments were manufactured by mixing concrete under the conditions shown in [Table 1] below and then molding and curing the segment test specimens. Curing was carried out in the following way: 2 hours of air-dry curing, 6 hours of hot water curing, then 7 days of underwater curing, and then 21 days of constant temperature and humidity curing.

Comparative Example 1 is a mix using cement (70%) and three types of blast furnace slag fine powder (30%) as binders, and Comparative Example 2 is a mix using conventional segment binders as binders (70% cement, 10% type 1 fly ash, Type 3 blast furnace slag fine powder (20%). Comparative Example 3 and Example 1 were the same as cement (10%) + 3 types of blast furnace slag fine powder (73%), supercritical fluidized bed boiler fly ash (5%), natural anhydrous gypsum (7%), and silica fume SF (2%). %) and CSA (3%). However, unlike Comparative Example 3, which used three types of blast furnace slag fine powder (specific gravity 2.80 to 2.90, fineness 4,000 to 5,000 cm ² /g) and conventional natural anhydrous gypsum powder, Example 1 was prepared according to [Preparation Example 1]. A high-fine powder material was used.

division W/B
(%) S/a
(%) Binder
Unit Weight(kg/m ³ ) Aggregate Ad.(%) OPC FA GGBS CFBC C.S. science fiction CSAs Sum S1 G1 PC Comparative Example 1 32.3 44.5 329 - 141 - - - - 470 777 970 3.70 Comparative example 2 32.3 42.5 329 47 94 - - - - 470 727 986 Comparative example 3 32.3 42.4 47 - 343.1 23.5 32.9 9.4 14.1 470 730 991 Example 1 32.3 47 - 343.1 23.5 32.9 9.4 14.1 470 1) OPC: Type 1 Ordinary Portland Cement
2) FA: Type 1 fly ash
3) CFBC: Supercritical fluidized bed fly ash
4) GGBS: 3 types of blast furnace slag fine powder
5) CS: Natural anhydrous gypsum
6) SF: Silica Fume
7) CSA: Calcium sulfoaluminate
8) PC: polycarboxylic acid-based admixture

2. Concrete properties

Slump (KS F 2402), air volume (KS F 2421), and compressive strength (KS F 2405) were measured for the test specimen, and water permeability was evaluated. For water permeability evaluation, (1) waterproof the side of the test specimen with paraffin or epoxy resin, (2) measure the mass (W1) of the test specimen when the waterproofing material is completely hardened, and then use a water permeability test device to measure 0.1 N /mm ² Apply water pressure for 1 hour, (3) remove the water pressure-applied test specimen from the water permeability test device, remove moisture from the surface, measure the mass (W2), and then (4) test mortar (Comparative Examples 2 and 3, Example 1) and standard mortar (comparative example 1) were measured for permeability (W2-W1), and the permeability ratio (permeability of test mortar/standard) was calculated by taking the average value of the remaining three measurements excluding the highest and lowest values among the five test specimens. The permeability of the mortar) was obtained. The results are shown in [Table 2] below.

concrete properties division Comparative Example 1 Comparative example 2 Comparative Example 3 Example 1 Slump(mm) 75 60 60 55 air(%) 3.8 4.3 4.2 4.0 compressive strength
(MPa) 3d 38.1 35.3 38.1 39.1 7d 44.1 43.0 50.0 52.3 28d 53.6 56.1 61.8 63.9 permeability
(pitching fee) 7d 1.00 0.97 0.98 0.94 28d 1.00 0.93 0.91 0.89

As shown in [Table 3] above, it was confirmed that Example 1 using the binder according to the present invention had improved early strength and significantly improved mid- to long-term strength than Comparative Examples 1.2 and 3. According to these results, the binder according to the present invention can be advantageously used as a high-strength binder for segments.

[Preparation Example 2] Preparation of additives

An alumina ball mill that can accommodate up to 5kg contains 5-10% stearic acid (ST) or sodium nitrate (SN) or sodium sulfate (SS) and 5-10% supercritical fluidized bed fly ash (based on the weight of the alumina ball mill). CFBC), add ceramic balls (5.0mm, 10.0mm, 30.0mm) in the same quantity at 5-10% of the weight of the alumina ball mill, and then add 1.0-1.5% of liquid glycerin as a grinding aid compared to the weight of the binder to mix 0.5%. Grinding was performed by maintaining 200-250 RPM for -1.5 hours. The sample after completion of grinding was sieved through a 0.075 mm sieve to prepare additives.

[Test Example 2] Characteristics of segment concrete according to the type of additive

1. Test specimen preparation

Concrete was mixed under the conditions shown in [Table 3] below, and a test specimen was manufactured through the same process as Test Example 1. Comparative Examples 4 to 6 and Examples 2 and 3 were mixed with the same binder as Example 1 of Test Example 1 with different types of additives. Comparative Example 4 is a blend using sodium nitrate and supercritical fluidized bed boiler fly ash as additives, Comparative Example 5 is a blend using sodium sulfate added to Comparative Example 3, and Comparative Example 6 is a blend using stearic acid and supercritical fluidized bed boiler fly ash as additives. This is the formulation used, and Comparative Example 7 and Example 2 are formulations in which stearic acid was added to Comparative Example 5. Comparative Examples 4 to 6 and Example 2 used the additive prepared according to [Preparation Example 2], and Comparative Example 7 used the ingredients of the additive in the raw material state.

concrete mix division W/B
(%) S/a
(%) Binder
Unit Weight(kg/m ³ ) Aggregate Ad.(%) S1 G1 S.N. SS S.T. CFBC PC Comparative example 4 32.3 42.4 470(OPC: 47, GGBS: 343.1, CFBC: 23.5,
CS: 32.9;
SF: 9.4;
CSA: 14.1) 730 991 0.4 - - 0.7 3.70 Comparative Example 5 32.3 0.4 0.4 - 0.7 Comparative Example 6 32.3 - - 0.5 0.7 Comparative example 7 32.3 0.4 0.4 0.5 0.7 Example 2 32.3 0.4 0.4 0.5 0.7 1) SN: Sodium nitrate
2) SS: Sodium sulfate
3) ST: stearic acid
4) CFBC: Supercritical fluidized bed boiler fly ash

2. Concrete properties

In the same manner as [Test Example 1], slump, air volume, and compressive strength were measured for the segment test specimen, and water permeability was evaluated. The results are shown in [Table 4] below.

concrete properties division
Comparative example 4 Comparative Example 5 Comparative Example 6 Comparative example 7 Example 2 Slump(mm) 65 65 70 70 75 air(%) 4.3 4.2 4.0 4.1 4.1 compressive strength
(MPa) 3d 40.2 41.9 38.3 39.9 42.3 7d 53.9 54.0 51.1 52.8 51.9 28d 65.8 66.8 62.7 64.5 66.1 permeability
(pitching fee) 7d 0.90 0.89 0.84 0.90 0.79 28d 0.82 0.83 0.80 0.82 0.67

As shown in [Table 4] above, Example 2 showed improved fluidity, improved early strength as well as mid- to long-term strength compared to Comparative Examples 4 to 7, and in particular, water permeability was significantly improved. According to these results, the concrete according to the present invention can be advantageously used in segment production as a high-strength watertight concrete.

Claims (3)

70 to 80% by weight of fine blast furnace slag powder with a fineness of 6,000±500 cm ² /g; 5 to 15% by weight of natural anhydrous gypsum fine powder with a fineness of 4,500 ± 500 cm ² /g; Type 1 ordinary Portland cement 5 to 15% by weight; Supercritical fluidized bed boiler fly ash 5-10% by weight; 2 to 5% by weight of silica fume; Consists of 2 to 5% by weight of CSA expansion material,
The blast furnace slag fine powder is obtained by pulverizing three types of blast furnace slag fine powder with a grinding aid added and treated into a fine powder,
The natural anhydrous gypsum fine powder is a high-strength binder composition for continuous excavation segments of underground structures, characterized in that the natural anhydrous gypsum powder is pulverized with a grinding aid added and treated into a fine powder. delete In concrete mixing using the high-strength binder composition for segments according to claim 1,
For 100 parts by weight of binder, 0.1 to 0.5 parts by weight of sodium nitrate, 0.1 to 0.5 parts by weight of sodium sulfate, 0.1 to 1.0 parts by weight of stearic acid, and 0.1 to 1.0 parts by weight of supercritical fluidized bed boiler fly ash are mixed and mixed,
High-strength watertight concrete for continuous excavation segments of underground structures, characterized in that the sodium nitrate, sodium sulfate, stearic acid, and supercritical fluidized bed boiler fly ash are ground and mixed with a grinding aid added.