KR102551892B1 - Additive for Strength Development of Type Ⅰ Slag Cement and Slag Cement Concrete Using the Same - Google Patents

Abstract

The present invention relates to a strength enhancer for type 1 blast furnace slag cement, a preferred method for producing the strength enhancer, and a blast furnace slag cement concrete using the strength enhancer.
The strength enhancer for type 1 blast furnace slag cement according to the present invention includes 30 to 40 parts by weight of sodium thiocyanate (NaSCN); 10 to 30 parts by weight of potassium phosphate (KH ₂ PO ₄ ); 10 to 30 parts by weight of sodium nitrate (NaNO ₃ ); 25 to 45 parts by weight of supercritical fluidized bed boiler fly ash; and 1 to 5 parts by weight of glycerin; may be further included. The strength enhancer prepares a first pulverized mixture by pulverizing and mixing a portion of the supercritical fluidized bed boiler fly ash, potassium phosphate, and sodium thiocyanate in order while putting them into a pulverizing mixer, while the rest of the supercritical fluidized bed boiler fly ash, It can be preferably prepared by preparing a second pulverized mixture by pulverizing and mixing while sequentially introducing sodium nitrate into a mixer, and then introducing the first pulverized mixture and the second pulverized mixture into a mixing mixer and mixing them. The strength enhancer thus prepared is suitably blended by mixing 0.25 to 2.00 parts by weight with 100 parts by weight of type 1 blast furnace slag cement in the blast furnace slag cement concrete mixture.

Description

Strength enhancer for type 1 blast furnace slag cement and blast furnace slag cement concrete using the same {Additive for Strength Development of Type Ⅰ Slag Cement and Slag Cement Concrete Using the Same}

The present invention relates to an admixture for enhancing the strength of a type 1 blast furnace slag cement having a blast furnace slag fine powder content of 5 to 30% by weight, a method for preparing the admixture, and a blast furnace slag cement concrete using the admixture.

The cement industry is the second largest carbon emitter after the electricity industry. Accordingly, many studies are being conducted to suppress the use of cement, and blast furnace slag cement is one of them. Blast furnace slag cement is a mixed cement that reduces the use of cement by partially replacing cement with blast furnace slag.

Since the reaction time of blast furnace slag cement is slower than that of general cement, blast furnace slag cement concrete has a slow development of initial strength, and also has problems with durability degradation such as increased self-shrinkage, plastic shrinkage, and initial drying shrinkage. In general, blast furnace slag cement is used together with an alkali activator to improve concrete strength.

In industrial sites, the 2-type blast furnace slag cement (30 to 60% by weight of 3-type blast furnace slag) suggested by the KS L 5210 standard is usually used. This is because it is much more advantageous in terms of long-term strength when using type 2 blast furnace slag cement.

Meanwhile, KDS 14 20 40, the durability design standard for concrete structures, has recently been revised. It is intended to increase the lifespan of buildings by improving durability (resistance to carbonation of concrete), which is an important criterion for determining the lifespan of concrete buildings. In the revised design standard, the concrete design compressive strength required for durability has been increased, apart from the safety related to the load capacity of members. In particular, concrete outer walls and handrails that are exposed to rain are exposed to the risk of carbonation due to repeated dry and wet conditions, and should be designed with EC4 grade and minimum design compressive strength of concrete of 30MPa. , the concrete should be designed with a minimum design compressive strength of 27 MPa.

However, type 2 blast furnace slag cement is not suitable for the current situation because durability such as carbonation of concrete is rapidly reduced. For this reason, research is being attempted to activate Type 1 blast furnace slag cement (Type 3 blast furnace slag content: 5-30%) in a form in which the amount of blast furnace slag fine powder is minimized. However, type 1 blast furnace slag cement has disadvantages such as delayed setting and lowered initial strength, and improvement is required. Considering the fact that the period of the wet process is longer than the scheduled period due to the recent climate change and the period of the interseason and winter period is longer, improvement of the disadvantages of the first type blast furnace slag cement is more urgent.

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

The present invention was developed to activate the use of type 1 blast furnace slag cement by improving the disadvantages of type 1 blast furnace slag cement (content of 5 to 30% by weight of type 3 blast furnace slag powder), and when used with type 1 blast furnace slag cement, There is a technical challenge in providing a strength enhancer for type 1 blast furnace slag cement that expresses concrete carbonation resistance performance superior to that of type blast furnace slag cement and also expresses physical performance (compressive strength) equivalent to 100% of OPC.

In addition, the present invention is to provide a preferred method of manufacturing a strength enhancer for type 1 blast furnace slag cement, and a blast furnace slag cement concrete using the strength enhancer.

In order to solve the above technical problem, the present invention, sodium thiocyanate (NaSCN) 30 to 40 parts by weight; 10 to 30 parts by weight of potassium phosphate (KH ₂ PO ₄ ); 10 to 30 parts by weight of sodium nitrate (NaNO ₃ ); 25 to 45 parts by weight of supercritical fluidized bed boiler fly ash; provides a first type blast furnace slag cement strength enhancer composition, characterized in that consisting of. The strength enhancer composition may further include 1 to 5 parts by weight of glycerin.

In addition, the present invention is a method for preferably preparing a strength enhancer for blast furnace slag cement, in which a part of the supercritical fluidized bed boiler fly ash, potassium phosphate, and sodium thiocyanate are sequentially put into a grinding mixer and pulverized and mixed. While preparing the pulverization mixture, prepare the second pulverization mixture by pulverizing and mixing the rest of the supercritical fluidized bed boiler fly ash and sodium nitrate while sequentially introducing them into the pulverization mixer, and then mixing the first pulverization mixture and the second pulverization mixture in a mixing mixer. It provides a method for producing a strength enhancer for type 1 blast furnace slag cement, characterized in that it is added to and mixed. At this time, the first pulverization mixture may be prepared by first pulverizing and mixing a part of the supercritical fluidized bed boiler fly ash, potassium phosphate, and sodium thiocyanate in order in a pulverizing mixer, and then adding glycerin to secondary pulverization and mixing. .

Furthermore, the present invention is characterized in that in concrete mixing, 0.25 to 2.00 parts by weight of a strength enhancer for type 1 blast furnace slag cement is mixed with 100 parts by weight of type 1 blast furnace slag cement containing 5 to 30% by weight of blast furnace slag fine powder, It provides blast furnace slag cement concrete.

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

First, the usability of type 1 blast furnace slag cement having a fine powder content of type 3 blast furnace slag of 5 to 30% by weight can be expanded. In other words, when the strength enhancer of the present invention is incorporated into a concrete mix using type 1 blast furnace slag cement, it is possible to secure early and mid-term strength at the OPC level and reduce length change, while securing long-term strength and bleeding, which are the advantages of blast furnace slag cement concrete. reduction and improved resistance to penetration of chlorine ions, so the usability of type 1 blast furnace slag cement is expanded.

Second, as the usability of type 1 blast furnace slag cement expands, it becomes possible to reduce the amount of cement used together with the increase in the amount of fine powder of blast furnace slag, which is an industrial by-product, thereby contributing to the suppression of carbon dioxide emissions.

The present invention relates to a type 1 blast furnace slag cement strength enhancer for improving the physical properties of a type 1 blast furnace slag cement having a powder content of 5 to 30% by weight of type 3 blast furnace slag, and a blast furnace slag cement concrete using the same.

1. Strength enhancer for type 1 blast furnace slag cement

The first type of strength enhancer for blast furnace slag cement according to the present invention is an admixture in which an alkali activator that stimulates the fine powder of blast furnace slag and a hardening accelerator that stimulates and promotes the cement are properly formulated. It is an admixture that can improve the cracking problem and improve the physical performance to improve the carbonation inhibitory performance of concrete. Specifically, the strength enhancer for type 1 blast furnace slag cement according to the present invention includes 30 to 40 parts by weight of sodium thiocyanate (NaSCN); 10 to 30 parts by weight of potassium phosphate (KH ₂ PO ₄ ); 10 to 30 parts by weight of sodium nitrate (NaNO ₃ ); 25 to 45 parts by weight of supercritical fluidized bed boiler fly ash; and 1 to 5 parts by weight of glycerin; may be further included.

Sodium thiocyanate (NaSCN) rapidly elutes Ca ²⁺ ions in cement to promote the hydration of 3CaO·SiO ₂ , a component that plays an important role in early strength of cement, and eventually promotes the hardening reaction of cement. Sodium thiocyanate is used in an amount of 30 to 40 parts by weight. If it is less than 30 parts by weight, the effect of accelerating cement hardening is insignificant, and if it exceeds 40 parts by weight, economic feasibility is lost.

Potassium phosphate (KH ₂ PO ₄ ) stimulates the fine powder of blast furnace slag to help increase strength. Potassium phosphate is combined with MgO, CaO, and mixed water (H ₂ O) of blast furnace slag powder to form Mg K PO ₄ 6H ₂ O (MgO + KH ₂ PO4 + 5H ₂ O → Mg K PO4 6H ₂ O) Hydrates, Ca K PO ₄ 6H ₂ O (CaO + KH ₂ PO4 + 5H ₂ O → Ca K PO 4 6H ₂ O)CaO + KH ₂ PO4 + 5H ₂ O → Ca K ·PO4·6H ₂ O) hydrates are created, and the hydrates generated in this way stimulate the fine powder of blast furnace slag in concrete to help increase the strength after 3 days of age. Potassium phosphate is used in an amount of 10 to 30 parts by weight, and if it is less than 10 parts by weight, the strength enhancing effect is insignificant.

Sodium nitrate (NaNO ₃ ) serves to promote cement hydration by increasing the pH of Na+ ions, and at the same time serves as a filler that allows the concrete composition to be mixed evenly. In addition, sodium nitrate (NaNO ₃ ) contributes to securing usability at low temperatures by lowering the condensation temperature of mixed water with SNO ₃ ^- ions. Sodium nitrate is used in an amount of 10 to 30 parts by weight. If it is less than 10 parts by weight, the effect of accelerating the hydration reaction is insignificant, and if it exceeds 30 parts by weight, there are concerns about reduced fluidity and loss of economy.

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. It is an ash with a fineness of 6,000 to 9,000 cm2/g while containing Common fly ash is ash discharged from the process of burning (1200-1500 degrees) by injecting fuel (coal) and air in coal-fired thermal power plants. It is ash discharged through the process of completely burning coal (760 to 950 degrees) while circulating heat with the supercritical fluidized bed boiler. It is ash discharged in the process of burning fuel (coal) in a supercritical state by injecting oxygen instead of air in a boiler) that generates electricity by applying steam temperature of 374 degrees. These fly ash have a common point in that they are ash discharged from power generation facilities using coal as fuel, but the specific treatment method of power generation facilities is different, so there are differences in the chemical composition and physical properties of fly ash.

Supercritical fluidized bed boiler fly ash is a component of a large amount of CaO and SO ₃ that reacts with C3A of cement through a pozzolanic reaction to generate ettringite, contributing to the improvement of strength performance. In addition, since the absorption rate is high due to the high fineness and uneven grain porosity, it contributes to plastic shrinkage by appropriately controlling the bleeding, which is a disadvantage of blast furnace slag cement concrete. Furthermore, supercritical fluidized bed boiler fly ash serves as a filler so that other materials can be mixed evenly. In particular, sodium thiocyanate and potassium phosphate, etc., which tend to lose proper dispersing ability due to deliquescent and increase hygroscopicity, can be uniformly dispersed. is to do Supercritical fluidized bed boiler fly ash is used in an amount of 25 to 45 parts by weight. If it is less than 25 parts by weight, the dispersion effect, bleeding control effect, and strength enhancement effect are insignificant. .

Glycerin (C ₃ H ₅ (OH) ₃ ) serves to suppress aggregation that may occur during grinding and mixing of sodium thiocyanate, potassium phosphate, and supercritical fluidized bed boiler fly ash and increase grinding efficiency. In addition, glycerin contributes to reducing the drying shrinkage of concrete by alleviating the surface tension of the mixing water when mixing concrete, thereby suppressing the occurrence of concrete cracks and further carbonation of the concrete structure. However, glycerin retards the hydration of cement to alleviate the acceleration of setting by sodium nitrate of the alkaline active part, and excessive delay in hydration interferes with the acceleration of hardening, so it is important to use it in an appropriate range. Considering the role of glycerin, the appropriate range of glycerin is preferably 1 to 5 parts by weight. If it is less than 1 part by weight, the grinding performance improvement effect and crack reduction improvement effect are insignificant, and if it exceeds 5 parts by weight, there is a risk of lowering the compressive strength and reducing economic feasibility.

Since the strength enhancer for blast furnace slag cement prepared with the above composition may be difficult to uniformly disperse when mixed at the same time due to the deliquescence of some materials, the present invention proposes a preferred manufacturing method. First, a first pulverized mixture is prepared by pulverizing and mixing a part of the supercritical fluidized bed boiler fly ash (about 50% of the prepared amount), potassium phosphate, and sodium thiocyanate in order in a pulverizing mixer. The material with high deliquescence is added last so that it can be properly dispersed and pulverized. can give Proper dispersion is possible because the porous supercritical fluidized bed boiler fly ash serves as a filler so that it can be mixed evenly due to its high water absorption. The first grinding mixture can be prepared by further including glycerin. In this case, some of the fly ash of the supercritical fluidized bed boiler, potassium phosphate, and sodium thiocyanate are sequentially introduced into the grinding mixer, and glycerin is added after the first grinding and mixing. Prepare by adding the second grinding and mixing. Since glycerin is additionally added and pulverized and mixed, the pulverization efficiency is further increased and the aggregation of the pulverized mixture can be prevented. In this way, since the first pulverized mixture is pulverized through pulverization and mixing, it is possible to increase reactivity by dissolving more quickly in H ₂ O (mixing water) during concrete mixing.

Along with the preparation of the first pulverization mixture, the second pulverization mixture is prepared by pulverizing and mixing the rest of the supercritical fluidized bed boiler fly ash and sodium nitrate in order while being introduced into the pulverization mixer. Similarly to the first grinding mixture, sodium nitrate is added last to the second grinding mixture so that it can be properly dispersed and mixed and ground.

After the preparation of the first and second pulverized mixtures is completed, the first and second pulverized mixtures may be put into a mixing mixer and mixed. As a result, the strength enhancer for type 1 blast furnace slag cement according to the present invention is prepared, and the strength enhancer for type 1 blast furnace slag cement thus prepared can be simply applied at the site in a state in which all constituent materials are premixed, in the same way as in the method of using a general admixture. .

2. Blast furnace slag cement concrete

The strength enhancer for type 1 blast furnace slag cement according to the present invention can be advantageously applied to concrete mixing using type 1 blast furnace slag cement. In other words, when 0.25 to 2.00 parts by weight of a type 1 blast furnace slag cement strength enhancer is mixed and mixed with 100 parts by weight of type 1 blast furnace slag cement containing 5 to 30% by weight of blast furnace slag fine powder, compressive strength, bleeding rate and length change It becomes blast furnace slag cement concrete, which is advantageous in terms of durability such as concrete carbonation and chloride ion penetration resistance.

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

[ Manufacture Example] Preparation of strength enhancer for type 1 blast furnace slag cement

1. Strength enhancer composition for type 1 blast furnace slag cement

A strength enhancer composition for type 1 blast furnace slag cement was prepared. Comparative Example 1 was prepared with a composition of 30 parts by weight of sodium thiocyanate and 15 parts by weight of supercritical fluidized bed boiler fly ash, and Comparative Example 2 was prepared with 30 parts by weight of sodium thiocyanate, 15 parts by weight of potassium phosphate, and 15 parts by weight of supercritical fluidized bed boiler fly ash. 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 nitrate, 20 parts by weight of supercritical fluidized bed boiler fly ash, and 20 parts by weight of glycerin.

Example 1 was prepared with a composition of 30 parts by weight of sodium thiocyanate, 15 parts by weight of potassium phosphate, 20 parts by weight of sodium nitrate, and 30 parts by weight of supercritical fluidized bed boiler fly ash (in Comparative Example 2, sodium nitrate, supercritical fluidized bed boiler fly ash addition), Example 2 was prepared with a composition of 30 parts by weight of sodium thiocyanate, 15 parts by weight of potassium phosphate, 20 parts by weight of sodium nitrate, 30 parts by weight of supercritical fluidized bed boiler fly ash, and 5 parts by weight of glycerin (Comparative Example 3 and composition different).

2. Manufacture of strength enhancer for type 1 blast furnace slag cement

A strength enhancer for blast furnace slag cement was prepared using the prepared composition. Comparative Examples 1 and 2 and Examples 1 and 2 were prepared by crushing and mixing, and Comparative Example 3 was prepared by simple mixing.

Specifically, Comparative Example 1 was prepared by first introducing supercritical fluidized bed boiler fly ash into a grinding mixer, then adding sodium thiocyanate and pulverizing and mixing for 5 minutes, and Comparative Example 2 prepared supercritical fluidized bed boiler fly ash, phosphoric acid in a grinding mixer, It was prepared by adding potassium and sodium thiocyanate in sequence and pulverizing and mixing for 5 minutes.

In Example 1, 15 parts by weight of supercritical fluidized bed boiler fly ash was first added to a grinding mixer, and then potassium phosphate and sodium thiocyanate were sequentially added and pulverized and mixed for 5 minutes to prepare a first pulverized mixture. First, 15 parts by weight of fluidized bed boiler fly ash was added, followed by 20 parts by weight of sodium nitrate, and pulverized and mixed for 5 minutes to prepare a second pulverized mixture, and then the first and second pulverized mixtures were mixed in a mixing mixer for 10 minutes. Example 2 was generally prepared in the same manner as Example 1, except that the first milling mixture was sequentially added with supercritical fluidized bed boiler fly ash, potassium phosphate, and sodium thiocyanate, followed by primary grinding and mixing for 5 minutes, and then glycerin It was prepared by adding additionally and performing secondary grinding and mixing for 5 minutes.

[Test Example] Properties of blast furnace slag cement concrete

1. Blast Furnace Slag Cement Concrete Mixing

Using the strength enhancer prepared according to [Preparation Example], blast furnace slag cement concrete was mixed as shown in [Table 1] below. As can be seen, Control Example 1 is a mixture using ordinary Portland cement (OPC), and Control Examples 2 and 3 use one type of blast furnace slag cement (blast furnace slag fine powder (SP) content of 10% by weight and 20% by weight, respectively). It is a formulation, and all of Control Examples 1, 2, and 3 are formulations in which the strength enhancer of Preparation Example is not incorporated. Comparative Examples 1 to 3 and Examples 1 and 2 are blended using one type of blast furnace slag cement (the content of blast furnace slag fine powder (SP) is 20% by weight, the same as in Control Example 3), and the strength enhancer of [Production Example] is a combination incorporating

Concrete mix (25-24-150) division W/B S/a W binder
(kg/m3) aggregate
(kg/m3) PC system
high performance
admixture robbery
enhancer
(B×%) OPC SP Sum fine aggregate coarse aggregate Control Example 1 48.0 49.0 168 350 - 350 857 894 2.80 - Control Example 2 315 35 350 855 894 - Control Example 3 280 70 350 855 891 - Comparative Example 1 280 70 350 855 891 0.25 Comparative Example 2 280 70 350 855 891 0.42 Comparative Example 3 280 70 350 855 891 0.70 Example 1 280 70 350 855 891 0.67 Example 2 280 70 350 855 891 0.70

2. Concrete properties

For concrete mixed as shown in [Table 1], compressive strength (KS F 2405), length change (Data Rogger (TDS-530) method), air volume and slump (KS F 2402, KS F 2421), chloride ion penetration resistance Physical property tests such as (KS F 2711), carbonation (KS F 2596), and bleeding (KS F 2414) were conducted. In particular, the compressive strength was measured by measuring the strength at an early age of 1 day after 24 hr in a constant temperature and humidity chamber in the range of 17 ~ 18 ℃ after fabrication of the test body, 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
(MPa) 1 day 5.6 4.9 4.8 5.1 5.3 4.9 5.6 5.7 3 days 24.8 22.7 21.6 22.0 22.4 23.0 24.1 24.9 7 days 32.3 31.8 31.6 31.8 32.1 30.9 32.6 33.0 28 days 37.4 38.4 41.6 41.9 42.4 42.1 43.0 43.4 Bleeding rate (%) 15.1 14.8 14.2 14.4 14.0 13.9 12.6 12.4 Slump(mm) 175 180 185 180 180 185 170 175 Air (%) 5.7 5.5 5.4 5.4 5.0 5.6 5.2 5.5 Length change (×10 ^-6 ) 28 days -694 -715 -740 -724 -721 -735 -711 -702 carbonation of concrete
Depth measurement (mm) 28 days 1.97 2.12 2.35 2.29 2.14 2.32 2.01 1.97 Chlorine ion permeation resistance
(Coulombs) 28 days 6,424 4,120 3,064 2,964 3,011 3,102 2,980 2,948

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 10 to 20% of cement was replaced with blast furnace slag fine powder, had significantly lower early and mid-term strength and length It is confirmed that the change is also reduced, but it is confirmed that the chlorine ion penetration resistance, fluidity (slump) and bleeding rate are improved. According to these results, it can be said that type 1 blast furnace slag cement requires an effective admixture to develop early and mid-term strength and reduce length change.

Comparative Example 1 is an example in which a strength enhancer prepared by pulverizing and mixing sodium thiocyanate and supercritical fluidized bed boiler fly ash as an admixture is added to Control Example 3. As can be seen, the compressive strength and length change at the initial age compared to Control Example 3 is confirmed to be slightly improved, but it is confirmed that it does not reach the level of Control Example 1. Comparative Example 2 is an example incorporating a strength enhancer prepared by adding more potassium phosphate to improve the early and middle compressive strength performance, which was somewhat lacking in Comparative Example 1, but the overall compressive strength performance slightly increased compared to Comparative Example 1. It is confirmed that it still falls short of the level of Control Example 1.

In Example 1, in order to further compensate for the insufficient early and mid-term strength in Comparative Example 2, sodium nitrate was further added for stimulation of the blast furnace slag fine powder, and at the same time, a strength enhancer prepared by further increasing the amount of supercritical fluidized bed boiler fly ash was incorporated. For example, as shown, the early and mid-term strengths are confirmed to be at the same level as Control Example 1, and excellent long-term strength is confirmed. However, the length change and carbonation depth showed slightly less results than Control Example 1. Example 2 is an example of incorporating a strength enhancer prepared by adding more glycerin to further complement Example 1, and was confirmed to be equal to or higher than Example 1 in strength and improved than Example 1 in length change and carbonation depth. Contrast It is confirmed that level 1 has been reached.

Comparative Example 3 is an example in which a strength enhancer having a change in the mixing amount and manufacturing method of potassium phosphate, supercritical fluidized bed boiler fly ash, and glycerin in Example 2 is incorporated. It showed poor performance in length change and carbonation depth.

According to the above results, when the strength enhancer (Examples 1 and 2) of the present invention prepared with an appropriate composition and manufacturing method is applied to a type 1 blast furnace slag cement concrete mixture, early strength, mid- and long-term strength are secured, and bleeding rate is reduced It is expected to contribute to suppression of plastic shrinkage and reduction of cracks due to reduction of length change. In addition, the chlorine ion penetration resistance is also excellent due to the fine powder of blast furnace slag.

Claims (5)

30 to 40 parts by weight of sodium thiocyanate (NaSCN); 10 to 30 parts by weight of potassium phosphate (KH ₂ PO ₄ ); 10 to 30 parts by weight of sodium nitrate (NaNO ₃ ); 25 to 45 parts by weight of supercritical fluidized bed boiler fly ash; 1 to 5 parts by weight of glycerin;
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. A strength enhancer composition for type 1 blast furnace slag cement, characterized in that the fineness is 6,000 ~ 9,000 cm2 / g while containing. delete A method for producing a strength enhancer for type 1 blast furnace slag cement with the composition according to claim 1,
A portion of the supercritical fluidized bed boiler fly ash, potassium phosphate, and sodium thiocyanate are put into a grinding mixer in order and pulverized and mixed to prepare a first pulverized mixture, while the rest of the supercritical fluidized bed boiler fly ash and sodium nitrate are sequentially pulverized. A method for producing a strength enhancer for type 1 blast furnace slag cement, characterized in that the second pulverized mixture is prepared by pulverization and mixing by putting it into a mixer, and then the first pulverized mixture and the second pulverized mixture are introduced into the mixing mixer and mixed. In paragraph 3,
The first pulverized mixture is prepared by adding a portion of the supercritical fluidized bed boiler fly ash, potassium phosphate, and sodium thiocyanate in order to a pulverizing mixer for primary pulverization and mixing, and then adding glycerin to secondary pulverization and mixing. Method for producing a strength enhancer for type 1 blast furnace slag cement. In concrete mixing using the strength enhancer for type 1 blast furnace slag cement prepared according to claim 3 or 4,
Blast furnace slag cement concrete, characterized in that 0.25 to 2.00 parts by weight of a strength enhancer for type 1 blast furnace slag cement is incorporated into 100 parts by weight of type 1 blast furnace slag cement containing 5 to 30% by weight of blast furnace slag fine powder.