KR102597189B1 - Hybrid Functional Additive for Slag Cement and Slag Cement Concrete Using the Same - Google Patents

Abstract

The present invention is a new functional additive composition that, when mixed into blast furnace slag cement concrete, enables early strength development in a low-temperature environment while maintaining initial fluidity, reduces initial drying shrinkage by controlling bleeding, and can also develop mid- to long-term strength. It relates to a preferable manufacturing method of a functional additive using the functional additive composition, and blast furnace slag cement concrete using the functional additive preferably.
The organic-inorganic composite functional additive composition for blast furnace slag cement according to the present invention contains 10 to 20% by weight of sodium thiocyanate (NaSCN); Potassium phosphate (KH ₂ PO ₄ ) 5-15% by weight; 15 to 30% by weight of sodium sulfate (Na ₂ SO ₄ ); Sodium nitrate (NaNO ₃ ) 5-15% by weight; 25 to 35% by weight of organic shrinkage reducing agent; The supercritical fluidized bed boiler is characterized in that it is composed of 10 to 40% by weight of fly ash. Here, the organic shrinkage reducing agent may preferably be pentyl glycol in flake form.

Description

Organic/inorganic composite functional additive for blast furnace slag cement and blast furnace slag cement concrete using the same {Hybrid Functional Additive for Slag Cement and Slag Cement Concrete Using the Same}

The present invention relates to a functional additive for blast furnace slag cement for improving the physical properties of blast furnace slag cement in which cement is partially replaced with blast furnace slag, and to blast furnace slag cement concrete using the same preferably, and more specifically, when mixed into blast furnace slag cement concrete. A new functional additive composition that allows development of early strength in a low temperature environment while maintaining initial fluidity, reduces initial drying shrinkage by controlling bleeding, and can also develop mid- to long-term strength, and the preferred functional additive using the functional additive composition. It relates to a manufacturing method and blast furnace slag cement concrete using functional additives preferably.

The cement industry is the second most carbon-emitting industry after the electric power industry. Accordingly, many studies are being conducted to suppress the use of cement with high carbon dioxide emissions, and blast furnace slag cement is one of them. Blast furnace slag cement is a method of reducing the use of cement by partially replacing cement with blast furnace slag.

Because the reaction time of blast furnace slag cement is slower than that of general cement, blast furnace slag cement concrete develops initial strength late, and also has durability problems such as self-shrinkage, plastic shrinkage, and increased initial drying shrinkage. Generally, blast furnace slag cement is used with an alkali activator to improve concrete strength, but the effect is minimal in low temperature environments below the standard temperature. In order to secure the required strength in a low-temperature environment, the amount of alkali activator must be increased. In this case, the initial fluidity is quickly lost and the concrete tends to set rapidly, and durability problems may occur outside the chloride content, which is the management standard for concrete. In addition, blast furnace slag cement concrete has problems such as increased plastic shrinkage and initial drying shrinkage due to bleeding. Therefore, there is a need for a new functional additive that can develop early strength in a low-temperature environment while maintaining initial fluidity, reduce initial drying shrinkage by controlling bleeding, and develop mid- to long-term strength.

Meanwhile, in recent construction sites, as the inter-season and winter periods have become longer due to climate change, the wet process period has become longer and there are difficulties in delaying the scheduled construction period. In addition, mechanized pump delivery is common for concrete construction, and in this case, excessive water mixing is made for the convenience of pump delivery, which frequently causes cracks and reduced structural strength after construction. Expanding materials are usually introduced as a way to reduce drying shrinkage of concrete, but expanding materials cause volume expansion through a hydration reaction and are usually very expensive, which limits their use in manufacturing economical products. In addition, if a large amount of expansion material is used, there is a risk of excessive expansion and destruction of the structure due to repeated or continuous supply of moisture due to rain, etc., so there is a limit to its use at construction sites.

KR 10-1244825 B1 KR 10-2013-0087663 A

The present invention was developed to propose a new blast furnace slag cement concrete that can be advantageously applied even in low-temperature environments. When incorporated into blast furnace slag cement concrete, it enables early strength development in low-temperature environments while maintaining initial fluidity and preventing bleeding. Provides a new functional additive composition that can control initial drying shrinkage and develop mid- to long-term strength, a preferred manufacturing method of the functional additive using the functional additive composition, and blast furnace slag cement concrete that preferably uses the functional additive. There are technical challenges in doing so.

In order to solve the above-described technical problem, the present invention includes 10 to 20% by weight of sodium thiocyanate (NaSCN); Potassium phosphate (KH ₂ PO ₄ ) 5-15% by weight; 15 to 30% by weight of sodium sulfate (Na ₂ SO ₄ ); Sodium nitrate (NaNO ₃ ) 5-15% by weight; 25 to 35% by weight of organic shrinkage reducing agent; It is composed of 10 to 40% by weight of supercritical fluidized bed boiler fly ash; the supercritical fluidized bed boiler fly ash is ash discharged through the process of burning coal fuel under supercritical conditions while injecting oxygen in the supercritical fluidized bed boiler, and is 5 to 40% by weight. An organic-inorganic composite functional additive composition for blast furnace slag cement is provided, which contains 20% by weight of SO ₃ and 20 to 30% by weight of CaO and has a fineness of 6,000 to 9,000 cm2/g. Here, the organic shrinkage reducing agent may preferably be pentyl glycol in flake form.

In addition, the present invention is a preferred method for producing an organic-inorganic composite functional additive for blast furnace slag cement, which involves grinding and mixing a portion of the supercritical fluidized bed boiler fly ash, potassium phosphate, and sodium thiocyanate in that order into a grinding mixer. While preparing the mixture, prepare the second mixture by sequentially adding the remainder of the supercritical fluidized bed boiler fly ash, sodium sulfate, sodium nitrate, and an organic shrinkage reducing agent into the mixer and mixing them, and then mixing the first mixture and the second mixture. It is possible to provide a method for manufacturing an organic-inorganic composite functional additive for blast furnace slag cement, characterized in that it is added to a mixer and mixed. Here, the second mixture can also be prepared by grinding and mixing in a grinding mixer.

Furthermore, the present invention, in concrete mixing using an organic-inorganic composite functional additive for blast furnace slag cement, contains oil for blast furnace slag cement in 100 parts by weight of a binder composed of 40 to 60% by weight of cement and 40 to 60% by weight of blast furnace slag fine powder. ·Provides blast furnace slag cement concrete, which is characterized by mixing 0.25 to 2.00 parts by weight of an inorganic composite functional additive.

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

First, the functional additive of the present invention, when incorporated into the blast furnace slag cement concrete mix, contributes to developing early strength and maintaining initial fluidity in a low-temperature environment, and also contributes to reducing initial drying shrinkage and improving mid- to long-term strength development through bleeding control. .

Second, since the blast furnace slag cement concrete of the present invention uses blast furnace slag fine powder instead of cement, it contributes to suppressing carbon dioxide emissions by reducing the use of cement, and exhibits excellent chlorine ion penetration resistance due to the blast furnace slab fine powder.

The present invention relates to an organic-inorganic composite functional additive for blast furnace slag cement to improve the physical properties of blast furnace slag cement, in which cement is partially replaced with blast furnace slag, and to blast furnace slag cement concrete using the same.

1. Organic/inorganic composite functional additive for blast furnace slag cement

The functional additive for blast furnace slag cement according to the present invention is an organic-inorganic composite functional additive that complements the shortcomings of commonly used alkali activators and hardening accelerators. In other words, when mixed into a blast furnace slag cement concrete mix, it is possible to maintain initial fluidity while improving initial strength and mid- to long-term strength, and also suppress cracking due to firing and drying shrinkage, which is a chronic disadvantage of blast furnace slag cement. . Specifically, the organic-inorganic composite functional additive according to the present invention contains 10 to 20% by weight of sodium thiocyanate (NaSCN); Potassium phosphate (KH ₂ PO ₄ ) 5-15% by weight; 15 to 30% by weight of sodium sulfate (Na ₂ SO ₄ ); Sodium nitrate (NaNO ₃ ) 5-15% by weight; 25 to 35% by weight of organic shrinkage reducing agent; Supercritical fluidized bed boiler is composed of 10 to 40% by weight of fly ash.

In functional additives, sodium thiocyanate (NaSCN) rapidly leaches Ca ²⁺ ions from cement, promoting the hydration of 3CaO·SiO ₂ , a component that plays an important role in the initial strength of cement, and ultimately promoting the hardening reaction of cement. . Sodium thiocyanate is used in an amount of 10 to 20% by weight. If it is less than 10% by weight, the effect of promoting cement hardening is minimal, and if it exceeds 20% by weight, economic feasibility is lost.

Potassium phosphate (KH ₂ PO ₄ ) helps improve strength by stimulating the fine powder of blast furnace slag. Potassium phosphate combines with MgO and CaO of blast furnace slag fine powder and mixed water (H ₂ O) to form Mg·K·PO ₄ 6H ₂ O (MgO + KH ₂ PO4 + 5H ₂ O → Mg·K·PO4·6H) ₂ O) hydrate, Ca·K·PO ₄ ·6H ₂ O(CaO + KH ₂ PO4 + 5H ₂ O → Ca·K·PO4·6H ₂ O)CaO + KH ₂ PO4 + 5H ₂ O → Ca·K ·PO4·6H ₂ O) Hydrates are generated, and the hydrates thus generated stimulate the fine powder of blast furnace slag in the concrete binder, helping to increase strength after 3 days of aging. Potassium phosphate is used in an amount of 5 to 15% by weight. If it is less than 5% by weight, the effect of improving strength is minimal, and if it exceeds 15% by weight, not only does it lose economic feasibility, but there are concerns about a decrease in strength.

Sodium sulfate (Na ₂ SO ₄ ) and sodium nitrate (NaNO ₃ ) serve to promote cement hydration reaction by increasing the pH of Na+ ions and at the same time serve as fillers to ensure even mixing of the concrete composition. In addition, sodium sulfate contributes to strength improvement by generating ettringite from SO4 ^2- ions and maintains the initial fluidity of concrete by appropriately alleviating the rapid reaction of 3CaO·Al2O3. Sodium sulfate is used in an amount of 15 to 30% by weight. If it is less than 15% by weight, the effect of improving strength is minimal, and if it exceeds 30% by weight, economic feasibility is lost. Meanwhile, sodium nitrate (NaNO ₃ ) contributes to ensuring usability at low temperatures by lowering the condensation temperature of the mixed water due to SNO ₃ ^- ions. Sodium nitrate is used in an amount of 5 to 15% by weight. If it is less than 5% by weight, the effect of promoting the hydration reaction is minimal, and if it exceeds 15% by weight, there are concerns about reduced fluidity and loss of economic feasibility.

The organic shrinkage reducing agent becomes a material that contributes to reducing drying shrinkage of concrete by dissolving the concrete capillary condensate and reducing the surface tension. Ultimately, the organic shrinkage reducing agent can suppress the occurrence of concrete cracks and further carbonation of the concrete structure. As an organic shrinkage reducing agent, plate-type neopentyl glycol can be preferably used. Organic shrinkage reducing agent is used at 25 to 35% by weight. If it is less than 25% by weight, the shrinkage reduction effect is minimal, and if it exceeds 35% by weight, there are concerns about poor initial and long-term strength and loss of economic feasibility.

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 5 to 20% by weight of SO ₃ and 20 to 30% by weight of CaO. It is an ash with a fineness of 6,000 to 9,000 cm2/g. General fly ash is ash discharged from a coal-fired power plant in the process of combustion (1200 to 1500 degrees) by injecting fuel (coal) and air, and circulating fluidized bed boiler fly ash is a continuous combustion process in which air and lime are simultaneously injected from a circulating fluidized bed boiler. It is ash discharged through the process of complete combustion of coal (760 to 950 degrees) while circulating heat through the supercritical fluidized bed boiler fly ash. It is ash emitted from the process of burning fuel (coal) in a supercritical state by injecting oxygen instead of air in a boiler (which generates power by applying steam temperature of 374 degrees). These fly ash have something in common in that they are ash discharged from coal-fired power generation facilities, but the specific processing methods of the power generation facilities are different, so there are differences in the chemical composition and physical properties of the fly ash.

Supercritical fluidized bed boiler fly ash contains a large amount of CaO and SO3 and reacts with C3A of cement through a pozzolanic reaction to produce ettringite, contributing to improved strength performance. In addition, because it has a high water absorption rate due to its high fineness and uneven particle shape, it contributes to plastic shrinkage by appropriately controlling bleeding, which is a disadvantage of blast furnace slag cement concrete. Furthermore, supercritical fluidized bed boiler fly ash acts as a filler so that other materials can be mixed evenly. In particular, sodium thiocyanate, potassium phosphate, and organic shrinkage reducing agents, which tend to lose their proper dispersion power as their deliquescent properties increase in hygroscopicity, can be uniformly dispersed. It acts as a filler. Supercritical fluidized bed boiler fly ash is used in an amount of 10 to 40% by weight. If it is less than 10% by weight, the dispersion effect, bleeding control effect, and strength improvement effect are minimal, and if it exceeds 40% by weight, there are concerns about concrete expansion, decreased fluidity, and decreased strength. .

Since the organic-inorganic composite functional additive composition for blast furnace slag cement prepared with the above composition may be difficult to uniformly disperse when mixed simultaneously due to the deliquescent nature of some materials, the present invention proposes a preferred manufacturing method. First, prepare the first mixture by grinding and mixing a portion of the supercritical fluidized bed boiler fly ash (about 50% of the preparation amount), potassium phosphate, and sodium thiocyanate in that order into a grinding mixer. Highly deliquescent substances are added last to ensure proper dispersion and grinding mixing. However, if highly deliquescent substances are added to the grinding mixer first, they stick to the inside of the mixer and compact, causing loss and resulting in changes in mixing ratio. can be given. Proper dispersion is possible because porous supercritical fluidized bed boiler fly ash acts as a filler to ensure even mixing due to its high absorption rate. In particular, the first mixture is ground and mixed in a grinding mixer, and this is to increase reactivity by allowing it to dissolve more quickly in H2O (mixing water) when mixing concrete through pulverization through grinding.

In addition to preparing the first mixture, the second mixture is prepared by sequentially adding the remainder of the supercritical fluidized bed boiler fly ash, sodium sulfate, sodium nitrate, and an organic shrinkage reducing agent into the mixer and mixing them. In the second mixture, like the first mixture, an organic shrinkage reducing agent with high deliquescent properties is added at the end to enable proper dispersion, mixing and grinding. Unlike the first mixture, it is sufficient to mix the second mixture in a general mixing mixer because the highly deliquescent organic shrinkage reducing agent has good solubility, but it can also be ground and mixed in a grinding mixer for the purpose of proper dispersion.

After preparing the first and second mixtures, simply add the first and second mixtures to the mixing mixer and mix. As a result, the functional additive for blast furnace slag cement according to the present invention is manufactured. The functional additive for blast furnace slag cement manufactured in this way has all the constituent materials premixed and can be easily applied in the field in the same way as a general admixture.

2. Blast furnace slag cement concrete

The organic-inorganic composite functional additive for blast furnace slag cement according to the present invention can be advantageously applied to mixing blast furnace slag cement concrete. In mixing blast furnace slag cement concrete, it is appropriate to use 40 to 60% by weight of ordinary Portland cement and 40 to 60% by weight of blast furnace slag fine powder (powder size 3,500 to 5,500 cm ² /g) as the binder. Here, the cement content is in a range that considers the initial strength and mid- to long-term strength, and the content of blast furnace slag powder is in a range that takes into account the initial and long-term strength along with the chlorine ion penetration resistance effect. In particular, blast furnace slag fine powder has a high fineness, and the SiO2 component inside the blast furnace slag undergoes a pozzolanic reaction with cement hydrate to produce CSH (Calcium silicate hydrate) hydrate, which is effective in improving strength and securing resistance to chloride ion penetration, so it is used considering economics and strength. Determine the scope. For 100 parts by weight of the binder of the above composition, it is appropriate for functionality and economic efficiency to mix 0.25 to 2.00 parts by weight of the organic-inorganic composite functional additive for blast furnace slag cement.

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.

[ Manufacture example] Manufacture of functional additives for blast furnace slag cement

1. Additive composition for blast furnace slag cement

An additive composition for blast furnace slag cement was prepared. Comparative Examples 1 to 3 were prepared using only inorganic materials. Comparative Example 1 was prepared solely with 20 parts by weight of sodium thiocyanate, and Comparative Example 2 was prepared with a composition of 20 parts by weight of sodium thiocyanate and 10 parts by weight of calcium phosphate, and Comparative Example 3 was prepared with a composition of 20 parts by weight of sodium thiocyanate, 10 parts by weight of potassium phosphate, 20 parts by weight of sodium sulfate, and 10 parts by weight of sodium nitrate. Examples 1 and 2 were prepared by adding organic materials to the inorganic materials, and both contained 20 parts by weight of sodium thiocyanate, 10 parts by weight of potassium phosphate, 20 parts by weight of sodium sulfate, 10 parts by weight of sodium nitrate, and 20 parts by weight of an organic shrinkage reducing agent. , a supercritical fluidized bed boiler was prepared with a composition of 20 parts by weight of fly ash.

2. Manufacturing additives for blast furnace slag cement

An additive for blast furnace slag cement was manufactured using a Junbihan composition. Comparative Examples 1 to 3 and Example 1 were prepared by simply mixing all the composition materials, while Example 2 was prepared separately as the first and second mixtures and then mixed according to the manufacturing method preferably proposed in the present invention. It was manufactured with . In particular, in Example 2, the first mixture was prepared by grinding and mixing by first adding 10 parts by weight of supercritical fluidized bed boiler fly ash to the grinding mixer, then adding 10 parts by weight of potassium phosphate, and finally adding 20 parts by weight of sodium thiocyanate. 2Mixture was prepared by first adding 10 parts by weight of supercritical fluidized bed boiler fly ash to the mixing mixer, followed by adding 20 parts by weight of sodium sulfate and 10 parts by weight of sodium nitrate, and finally adding an organic shrinkage reducing agent and mixing. ,2The mixture was prepared by mixing in a mixing mixer.

[Test example] Blast furnace slag cement concrete properties

1. Blast furnace slag cement concrete mixing

Blast furnace slag cement concrete was mixed using the functional additives prepared according to [Manufacturing Example] as shown in [Table 1] below. As can be seen, Control Examples 1, 2, and 3 are blends using different types of binders and do not contain the functional additives of the manufacturing example. Comparative Examples 1 to 4 and Example 1 are formulations containing the functional additives of [Preparation Example].

Concrete mix (25-24-150) division W/B S/a W binder
(kg/m3) aggregate
(kg/m3) PC world
high performance
admixture Functional
additive
(B×%) OPC SP Sum fine aggregate coarse aggregate Control example 1 48.0 49.0 168 350 - 350 883 920 2.80 - Control example 2 210 140 350 878 915 - Control example 3 175 175 350 876 915 - Comparative Example 1 175 175 350 876 915 0.15 Comparative example 2 175 175 350 876 915 0.20 Comparative Example 3 175 175 350 876 915 0.35 Example 1 175 175 350 876 915 0.50 Example 2 175 175 350 876 915 0.50

2. Concrete properties

For concrete mixed as shown in [Table 1], compressive strength (KS F 2405 Concrete Compressive Strength Test Method), length change (Data Rogger (TDS-530) method), and chlorine ion penetration resistance (KS F 2711 electrical conductivity) Test method for chlorine ion penetration resistance of concrete) and bleeding (KS F 2414 Bleeding Test Method for Concrete) tests were conducted. In particular, the compressive strength was measured by measuring the early strength 1 day after 24 hours in a constant temperature and humidity chamber at a temperature and humidity range of 10.5~12.9 ℃ after manufacturing the test specimen, and then curing under standard conditions (20℃±1℃). The test results are shown in [Table 2] below.

concrete properties division Control example 1 Control example 2 Control example 3 Comparative Example 1 Comparative example 2 Comparative Example 3 Example 1 Example 2 Compressive strength ¹⁾
(MPa) 1 day 3.1 2.4 1.9 2.7 3.0 3.3 3.0 3.3 3 days 21.1 10.8 8.0 10.7 11.0 11.7 11.9 12.4 7 days 33.2 26.2 23.7 27.9 28.2 29.9 34.8 35.6 28th 40.5 43.7 41.9 40.7 41.9 44.5 45.3 45.5 Bleeding rate (%) 16.4 13.9 11.4 9.2 9.4 9.7 7.0 6.9 Slump(mm) 180 200 220 205 215 215 220 220 Air(%) 5.0 5.3 5.5 4.9 5.2 5.0 5.5 5.4 Length change (×10 ^-6 ) 28th -621 -714 -779 -697 -701 -656 -464 -451 Chloride ion penetration resistance (Coulombs) 4,424.5 1,315.1 800.4 857.2 816.1 900.2 989.4 997.2

As shown in [Table 2] above, compared to Control Example 1 in which the binder was composed of 100% cement, Control Examples 2 and 3, in which 40-50% of the cement was replaced with fine blast furnace slag powder, had significantly lower early and mid-term strengths and shorter length. It is confirmed that the change is reduced, but the chlorine ion penetration resistance, fluidity (slump), and bleeding rate are confirmed to be improved. According to these results, it can be said that binders composed of two components of cement and blast furnace slag powder require functional additives that are effective in developing early and mid-term strength and reducing length change.

Comparative Example 1 is an example in which sodium thiocyanate and supercritical fluidized bed boiler fly ash were added as functional additives to the binder of Control Example 3. As can be seen, the compressive strength and length change at an early age were confirmed to be somewhat improved compared to Control Example 3. However, it was confirmed that the compressive strength decreased after 7 days and 28 days. Comparative Example 2 is an example in which potassium phosphate was added as a functional additive in addition to the functional additive of Comparative Example 1 to improve the early, mid-, and long-term compressive strength performance, which was somewhat insufficient in Comparative Example 1. It is more compressive than Comparative Example 1. It was confirmed that the strength performance increased slightly and was at the same level as Control Example 3 in terms of long-term strength. Comparative Example 3 is an example in which an alkali activator for stimulation of blast furnace slag fine powder was added in addition to the functional additive of Comparative Example 2 to further compensate for the insufficient long-term strength. As can be seen, the early strength in a low-temperature environment is equivalent to the level of Comparative Example 1. It was confirmed to be or higher, and the long-term strength was also measured at 44.5MP, confirming that it was superior to Control Examples 1 and 3 as well as Comparative Examples 1 and 2. However, Comparative Examples 1, 2, and 3 showed an overall increase in length change compared to Control Example 1, which used only cement.

Example 1 is an example in which an organic shrinkage reducing agent was added in addition to the functional additive of Comparative Example 3 to reduce length change. As can be seen, compared to Comparative Example 3, early, mid- and long-term strength, bleeding rate reduction, and length were improved. Excellent effects are confirmed in reducing changes. The chlorine ion penetration resistance tended to increase slightly compared to Comparative Example 3, but was confirmed to be a very low permeability grade at a level of less than 1,000 C. Example 2 is an example in which the functional additive of Example 1 was manufactured and mixed using the manufacturing method according to the present invention, and improved properties (early strength, change in length, etc.) compared to Example 1 were confirmed. Although Example 2 showed a more subtle improvement effect than Example 1, it is expected that Example 2 would show a further improvement effect in actual sites where the scale is significantly larger than the test conditions.

According to the above results, when the functional additive of the present invention (Examples 1 and 2) is applied to the blast furnace slag cement concrete mix, it secures early strength and mid- and long-term strength in a low-temperature environment, suppresses plastic shrinkage by reducing the bleeding rate, It is expected to contribute to reducing cracks by reducing length change. In addition, the chlorine ion penetration resistance will also be excellent due to the blast furnace slag-based binder.

Claims (5)

Sodium thiocyanate (NaSCN) 10-20% by weight; Potassium phosphate (KH ₂ PO ₄ ) 5-15% by weight; 15 to 30% by weight of sodium sulfate (Na ₂ SO ₄ ); Sodium nitrate (NaNO ₃ ) 5-15% by weight; 25 to 35% by weight of organic shrinkage reducing agent; Supercritical fluidized bed boiler is composed of 10 to 40% by weight of fly ash;
The supercritical fluidized bed boiler fly ash is ash discharged through a process of burning coal fuel under supercritical conditions while injecting oxygen in a supercritical fluidized bed boiler, and contains 5 to 20% by weight of SO ₃ and 20 to 30% by weight of CaO. It contains and has a fineness of 6,000 to 9,000 cm2/g,
The organic-inorganic composite functional additive composition for blast furnace slag cement, characterized in that the organic shrinkage reducing agent is pentyl glycol in the form of flakes. delete A method of producing an organic-inorganic composite functional additive for blast furnace slag cement with the composition according to paragraph 1,
The first mixture is prepared by grinding and mixing a portion of the supercritical fluidized bed boiler fly ash, potassium phosphate, and sodium thiocyanate in that order into a grinding mixer, while the remainder of the supercritical fluidized bed boiler fly ash, sodium sulfate, sodium nitrate, and organic The second mixture is prepared by mixing the shrinkage reducing agent in the mixer in order, and then the first mixture and the second mixture are mixed by adding them to the mixing mixer. Manufacturing method. In paragraph 3,
A method for producing an organic-inorganic composite functional additive for blast furnace slag cement, characterized in that the second mixture is prepared by grinding and mixing in a grinding mixer. In concrete mixing using the organic/inorganic complex functional additive for blast furnace slag cement manufactured in accordance with paragraph 3,
Blast furnace slag cement, characterized in that 0.25 to 2.00 parts by weight of an organic-inorganic complex functional additive for blast furnace slag cement is mixed with 100 parts by weight of a binder composed of 40 to 60% by weight of cement and 40 to 60% by weight of blast furnace slag fine powder. concrete.