KR101856380B1 - Concrete Composition Using Utilizing Liquid Activator - Google Patents

Abstract

The present invention relates to a concrete composition enhancing substitution ratio of silica based slag for concrete by using a liquefied activator and, more specifically, to a concrete composition enhancing substitution ratio of silica based slag for concrete by using a liquefied activator, which enhances substitution ratio for cement of the silica based slag for concrete obtained by finely crushing water-cooled ferronickel slag (prime sand) among industrial byproducts of ferronickel, which is a product of steel raw materials, to a level more than cement particles by using the liquefied activator. A desirable embodiment of the present invention contains: 165-169 kg/m^3 of water; 231-374 kg/m^3 of cement; 803-883 kg/m^3 of fine aggregate; 923-931 kg/m^3 of coarse aggregate; and 12-22 kg/m^3 of the liquefied activator, with respect to a unit volume of the concrete composition, wherein 25-35 wt% of the silica based slag for concrete is substituted and added with respect of 100 wt% of the cement. The liquefied activator contains: 20-60 wt% of polycarboxylate; 1-40 wt% of an additive; and 15-30 wt% of water. The additive contains: 40-60 wt% of TEA; 1-30 wt% of sodium nitrate (NaNO_3); and 1-20 wt% of citric acid.

Description

[Technical Field] The present invention relates to a concrete composition using a liquid activator,

The present invention relates to a concrete composition in which a silica-based slag for concrete is increased by using a liquid activator. More particularly, the present invention relates to a concrete composition using a liquid activator and a ferro- The present invention relates to a concrete composition in which the replacement ratio of silica-based slag for concrete obtained by pulverizing fine particles of a silica-based slag with a cement-particle-level to a level higher than that of cement is improved.

The production of mixed concrete using industrial byproducts such as thermal power plants and steel mills has produced a lot of researches in the past. In other words, development of various cement substitutes has become a source technology that leads to cost reduction of existing OPC (ordinary Portland Cement) or high performance (high durability, high strength, high flowability) concrete, In addition, the development of high performance admixture and optimum replacement rate for accelerating the early strength of cement substitute has attracted the attention of related workers. Herein, typical examples of conventional industrial wastes that have recently been recognized as admixtures include blast furnace slag fine powder, fly ash and silica fume. In the case of blast furnace slag fine powder and fly ash, And the demand for silica fume is compromised organically. In the case of silica fume, due to the lack of related factories and mass production facilities, it is dependent on imports in spite of its excellent quality. However, localization can be spread by 2015 The state has been reached.

On the other hand, ferronickel, which has emerged as a fourth material as a byproduct of recent steel industry, is most widely used as a main raw material of stainless steel. Nickel-based stainless steel has excellent heat resistance, corrosion resistance, acid resistance, abrasion resistance, In addition, it is an eco-friendly material which is harmless to human body and is used in kitchen utensils used in general households.

Ferronickel production The main processes are raw material disposal, drying, pre-reduction, melting reduction (electric furnace process), refining and casting processes. Finally, ferronickel containing about 20% nickel and about 80% The silica-based slag for concrete refers to a water-based by-product that occurs during the middle of the electric furnace process during the production of ferronickel.

Ferronickel slag is a useful resource obtained after nickel ore and bituminous coal used as raw materials to produce ferronickels are melted at high temperature and separated from ferronickel. Ferronickel slag is an eco-friendly resource with excellent physical and chemical properties. It is used as a substitute for natural resources such as concrete aggregate, foundry sand, abrasives, and serpentine substitutes, contributing to resource and environmental conservation. In Korea and other developed countries such as Japan and New Caledonia, ferronickel slag has been used in various ways for a long time. Ferronickel slag is classified as a prime sand produced by rapidly cooling molten slag by spraying water with prime stone produced by natural air cooling.

In the case of prime stone, the molten slag is cooled slowly by natural air cooling and is produced in gravel form. It is known that it has excellent compaction ratio when it is used as aggregate for civil works such as embankment material, roadbed material, asphalt aggregate, and serpentine substitute material.

In the case of prime sand, water is sprayed on molten slag to produce sand, which is superior to natural sand and can be used as concrete for sand.

However, there has been no case in which it has been developed as a substitute for bulk cement substitution. In the case of the domestic market, SNNC is the sole proprietor of the ferronickel slag production, Larco, Greece, developed ferroalloy slag substitute cement substitute, but it is incomparable with the existing ferronickel slag raw ore in terms of chemical composition.

As a background technique of the present invention, there is a patent registration No. 1247707 entitled " Mixture for Cement, Mortar and Concrete Containing Ferronickel Slag "(Patent Document 1).

In the above-mentioned background art, a mixed material for cement, mortar and concrete is characterized in that ferronickel slag is mixed with anisotrope, anhydrous gypsum or a mixture thereof, and the powdery degree is 4,000 to 10,000 cm ² / g. Concrete slag is used as a mixed material for cement, mortar and concrete. Thus, the recycling of the slag is still limited to a simple level, or it can be used only as a fine aggregate for roadbed or concrete By expanding the application range of ferronickel slag being utilized, it is possible to manufacture cement, mortar and concrete with excellent price competitiveness and high quality while reducing environmental load.

However, the background art can not increase the substitution ratio of cement of ferronickel slag, which is a limitation in use.

Patent Registration No. 1247707 "Mixture of cement, mortar and concrete containing ferronickel slag"

The present invention has been made to solve the above problems and it is an object of the present invention to solve the above problems and to provide a method for producing a concrete material for a concrete using a liquid activator, Based slag to cement can be increased to reduce cost due to substitution of cement substitute and to be able to be applied to concrete construction under various environmental conditions and to manufacture various mixed concrete structures requiring high durability, The present invention is directed to a concrete composition having improved silica-based slag replacement ratio.

The present invention relates to a concrete composition comprising 165 to 169 kg / m ^{3 of} water per unit volume of concrete composition; Cement 231 to 374 kg / m ³ ; Fine Aggregate 803 ~ 883kg / m ^3; Coarse aggregate 923 to 931 kg / m ³ ; And a liquid activator comprising 12 to 22 kg / m < ³ >, wherein 25 to 35% by weight of silica-based slag for concrete is added to 100 weight% of the cement, and the liquid phase activator is polycarboxylate 20 to 60 Wherein the additive comprises from 40 to 60% by weight of TEA, from 1 to 30% by weight of sodium nitrate (NaNO ₃ ) and from 1 to 20% by weight of citric acid, and the additive comprises from 1 to 40% Based slag for concrete using a liquid activator, which is characterized in that the amount of silica-based slag for concrete is increased.

Also, the silica-based slag for concrete is formed by finely pulverizing a water-based ferronickel slag in the industrial by-products of ferronickel. The present invention provides a concrete composition having enhanced silica-based slag replacement ratio for concrete.

(W / B) of 44.1 to 52.2% and a fine aggregate ratio (S / a) of 47.6 to 49.0% based on the design standard compressive strengths of 24 MPa, 27 MPa, 30 MPa and 35 MPa. The present invention provides a concrete composition having improved silica-based slag replacement ratio for concrete.

The specific gravity of the cement is 3.15, the weight of the fine aggregate is 2.1 to 2.7 g / cm ³ , the weight of the coarse aggregate is 2.1 to 2.9 g / cm ³ , the specific gravity of the silica-based slag for concrete is 3.04, the specific surface area is 3,800 cm ² / And the fine aggregate has a maximum dimension of 25 mm and an aggregation ratio of fine aggregate is in a range of 2.3 to 3.2. The present invention provides a concrete composition having enhanced silica-based slag substitution ratio for concrete.

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The concrete composition of the present invention using the liquid activator of the present invention in which the substitution ratio of the silica-based slag for concrete is increased, uses a liquid activator to convert the ferro-nickel slag (prime sand) among the industrial by- , It is possible to reduce the cost by replacing cement substitution and to apply to various concrete structures requiring concrete construction and high durability under various environmental conditions by increasing the substitution ratio of silica-based slag for concrete to cement There is a very useful effect possible.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments of the invention and, together with the description, serve to explain the principles of the invention, Shall not be construed as limiting.
FIG. 1 is a graph showing the results of compressive strength test according to age according to the replacement ratio of cement when silica-based slag for concrete is used as an admixture under general conditions.
2 is a view showing a result of strength test of a specimen using 100% Portland cement (OPC) and a specimen made of the concrete composition of the present invention in comparison with the results of strength tests.
3 is a graph comparing the price performance ratios according to the age diagrams of FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the embodiments shown in the accompanying drawings, but the present invention is not limited thereto.

Hereinafter, the technical structure of the present invention will be described in detail with reference to the preferred embodiments.

The present invention relates to a concrete composition in which the replacement ratio of silica-based slag for concrete is increased by using a liquid phase activator for increasing the replacement ratio of silica-based slag for concrete to cement using a liquid phase activator.

A preferred embodiment of the concrete composition in which the replacement ratio of the silica-based slag for concrete is increased by using the liquid activator of the present invention is 165 to 169 kg / m ^{3 of} water per unit volume of the concrete composition; Cement 231 to 374 kg / m ³ ; Fine Aggregate 803 ~ 883kg / m ^3; Coarse Aggregate 923 ~ 931kg / m ^3; made, including the liquid and the activator 12 ~ 22kg / m ^3, such that the silica-based slag concrete additive by substituting 25-35 wt% based on the 100% by weight of cement.

The silica-based slag for concrete used in the present invention is formed by finely pulverizing a water-based ferronickel slag in industrial by-products of ferronickel. In the industrial by-products of ferronickel, the water-based ferronickel slag is not reactive at all in the slag state, When the slag is finely pulverized to a certain size or less, the reactivity with cement increases, and thus it can be used as a mixed material for cement, mortar and concrete instead of simple aggregate.

Therefore, the silica-based slag for concrete used in the present invention is preferably formed by pulverizing a water-based ferronickel slag in the industrial by-products of ferronickel and having a specific surface area of 3,800 cm 2 / g to 60,000 cm 2 / g.

In general concrete using cement as a binder, the alkali environment of the concrete is formed by the calcium hydroxide generated in the hydration process, and the pozzolanic reaction or the latent hydraulic reaction of the fly ash or the blast furnace slag incorporated into the admixture under the thus prepared alkaline environment proceeds do. However, the higher the substitution ratio of the silica-based slag with the cement as the admixture, the lower the reactivity due to the relatively small amount of the cement used.

Therefore, it is preferable that a liquid activator is blended for smooth progress such as pozzolanic reaction and latent hydraulic reaction.

The liquid phase activator used in the present invention is composed of 20 to 60% by weight of polycarboxylate, 1 to 40% by weight of additives, and 15 to 30% by weight of water.

The polycarboxylate is used as a fluidizing agent which is constituted to exhibit a dispersing ability. When it is used in an amount of less than 20% by weight, dispersibility is not sufficiently exhibited when it is used and reactivity is poor. When it is mixed more than 60% by weight, By weight to 60% by weight.

The additives may be mixed with various additives for improving the reactivity so that the reactivity can be increased by increasing the fluidity and dispersibility together with the polycarboxylate.

Particularly, in the present invention, sodium nitrate (NaNO ₃ ) and citric acid are additionally used in addition to amine-based TEA (Tri-Ethanol-Amine) as an additive so that optimum mixing ratio can be derived to increase reactivity.

TEA (Tri-Ethanol-Amine) is used to accelerate the hydration reaction. Less than 40% by weight of TEA slows the reactivity when it is used. When it exceeds 60% by weight, %.

Sodium nitrate (NaNO ₃ ) is used as a crude steel and citric acid is used as a hardening retarder. It is preferably mixed with 1 to 30% by weight of sodium nitrate (NaNO ₃ ) and 1 to 20% by weight of citric acid, .

In the present invention, it is desirable that the water / binder ratio (W / B) is 44.1 to 52.2% and the fine aggregate ratio (S / a) is 47.6 to 49.0% based on the design standard compressive strengths of 24 MPa, 27 MPa, 30 MPa and 35 MPa. a specific gravity of 3.15, a unit weight of the fine aggregate 2.1 ~ 2.7 g / cm ^3, a unit weight of coarse aggregate 2.1 ~ 2.9 g / cm ^3, the proportion of concrete for a silica-based slag is 3.04, a specific surface area of 3,800㎠ / g ~ 60,000㎠ / g, the maximum size of the coarse aggregate is 25 mm, and the granulation ratio of the fine aggregate is in the range of 2.3 to 3.2.

FIG. 1 is a graph showing the results of compressive strength test according to age according to the replacement ratio of cement when silica-based slag for concrete is used as an admixture under general conditions.

As shown in FIG. 1, when the silica-based slag for concrete was used as an admixture under general conditions, the compressive strength of the silica-based slag for concrete at the design standard strength of 35 MPa was measured, Compressive strength was similar to that of silica based slag substitute for concrete of 20% compared with that of ordinary Portland cement (OPC) 100%, and then decreased linearly with increasing substitution rate .

2 is a view showing a result of strength test of a specimen using 100% Portland cement (OPC) and a specimen made of the concrete composition of the present invention in comparison with the results of strength tests.

W / B S / a W sand Pebble Binders usually
Portland cement Silica-based slag for concrete Replacement ratio Liquid phase
Activator 52.2 49.0 169 883
(VAR) 923
(VAR) 324 227 97


30%


0.7 to 0.9 wt% 51.4 48.8 169 877
(VAR) 924
(VAR) 329 230 99 46.7 48.1 165 859
(VAR) 931
(VAR) 353 247 106 44.1 47.6 165 843
(VAR) 931
(VAR) 374 262 112

The test specimens prepared with the concrete composition under the condition that the substitution rate of the silica-based slag fine powder for concrete was fixed up to 30% by using the liquid activating agent at the composition ratios as shown in Table 1 were repeatedly tested, In FIG. 2 (a), a test piece was made by using 30% by weight of polycarboxylate, 15% by weight of additives and 22% by weight of water. In FIG. 2b, 45% by weight of polycarboxylate, % Of water and 22 wt% of water.

The additive was composed of 50 wt% of TEA, 15 wt% of sodium nitrate, and 10 wt% of citric acid.

As shown in FIG. 2, when the liquid activator of the present invention was used to replace the silica-based slag for concrete with 30% as an admixture, the strength of the slag was tested. As a result, compared with the case of using ordinary Portland cement (OPC) Although the strength was slightly lower until 28 days, the compressive strength at 28 days was almost the same as that of 100% Portland cement (OPC).

That is, in the case of FIG. 1, the optimum range of the substitution rate of the silica-based slag powder for concrete to the cement in the ordinary mixed concrete is 20% However, in the present invention, as shown in Fig. 2, it is possible to increase the substitution rate through application of a customized liquid phase activator so as to increase the reactivity of the chemical components of the ferronickel slag raw material in order to increase the substitution ratio It is possible to improve the strength while still.

In the present invention, since the silica-based slag for concrete is used as an admixture, it is very economical compared to other existing admixtures. Therefore, by using the liquid activator of the present invention in which the replacement ratio of existing cement is increased to 30% The price of the concrete composition having an increased replacement ratio is 100% as compared with the case of using ordinary portland cement.

3A and 3B are graphs comparing the price performance ratios according to the age charts of FIGS. 2A and 2B, respectively.

As shown in FIG. 3, the result of the comparison of the price performance ratio (compression strength / price) according to each age strength is as follows. In order to reflect the conservative analysis, the average value of cement in ready- The price of KRW 73,000 / ton and the cost of 40,000 won / ton of concrete silica-based slag powder at the site arrival cost are analyzed by the ratio of strength-to-strength ratios according to substitution. As shown in the analysis results,

100%, compared with the test specimen using ordinary Portland cement, when the test specimen made of the concrete composition using the liquid activator of the present invention and having a higher replacement ratio of the silica-based slag for concrete is increased, about 114 to 115% It can be seen that it is superior in terms of the ratio of concrete to concrete.

The concrete composition of the present invention using the liquid activator of the present invention in which the substitution ratio of the silica-based slag for concrete is increased, uses a liquid activator to convert the ferro-nickel slag (prime sand) of the industrial raw material of ferronickel, It is possible to increase the substitution ratio of silica-based slag for concrete obtained by pulverization to an abnormal grain level and to reduce the cost by replacing cement substitution and to manufacture concrete composite structures requiring various concrete conditions and high durability There is also a very useful effect that can be applied to.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the above teachings. will be. The invention is not limited by these variations and modifications, but is limited only by the claims appended hereto.

Claims (6)

With respect to the unit volume of the concrete composition,
Water 165 to 169 kg / m ³ ; Cement 231 to 374 kg / m ³ ; Fine Aggregate 803 ~ 883kg / m ^3; Coarse aggregate 923 to 931 kg / m ³ ; And 12 to 22 kg / m < ³ > of liquid phase activator,
The silica-based slag for concrete is added in an amount of 25 to 35% by weight based on 100% by weight of the cement,
Wherein the liquid activator comprises 20 to 60 wt% of a polycarboxylate, 1 to 40 wt% of an additive, and 15 to 30 wt% of water, wherein the additive comprises 40 to 60 wt% of TEA, 1 to ₅ wt% of sodium nitrate (NaNO ₃ ) 30 wt.% And citric acid in an amount of 1 to 20 wt.% Based on the total amount of the silica-based slag for concrete. The method according to claim 1,
Wherein the silica-based slag for concrete is formed by pulverizing a water-based ferronickel slag in an industrial by-product of ferronickel, wherein the replacement ratio of the silica-based slag for concrete is increased by using the liquid phase activator. The method according to claim 1,
(W / B) of 44.1 to 52.2% and a fine aggregate ratio (S / a) of 47.6 to 49.0% based on the design standard compressive strengths of 24 MPa, 27 MPa, 30 MPa and 35 MPa. To increase the replacement ratio of the silica-based slag for concrete. The method according to claim 1,
The specific gravity of the cement is 3.15, the weight of the fine aggregate is 2.1 to 2.7 g / cm ³ , the weight of the coarse aggregate is 2.1 to 2.9 g / cm ³ , the specific gravity of the silica-based slag for concrete is 3.04 and the specific surface area is 3,800 cm ² / g to 60,000 cm 2 / g, the maximum size of the coarse aggregate is 25 mm, and the granulation ratio of the fine aggregate is 2.3 to 3.2. delete delete

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