• Journal of the Korean Recycled Construction Resources Institute
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• v.3 no.2
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• pp.171-179
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• 2015

Recently, development of substitution aggregate is urgently needed because aggregate shortage is continuing due to the exhaustion of natural aggregate and strict restrictions of environment in construction industry. Therefore, In this study, new processing method to solve the problems of processing method of existing converter slag, namely, rapid cooling slag produced by the rapid cooling and crushing process of the high temperature melten slag into the rotary drum and then using the cooling water, compressed air and steel ball was examined fundamental properties for utilize as fine aggregate for concrete. In addition, through this study, we propose the utilization method of rapid cooling slag as fine aggregate for concrete.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.3511-3517
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• 2015

It is necessary to maximize the durability of Concrete for the underground structure because its maintenance and reinforcement are difficult. For cracks due to drying shrinkage of the concrete on the characteristics of the material, there is a need for an alternative in the deterioration phenomenon that occurs. In this study, fundamental properties including drying shrinkage of mortar and concrete were investigated to replace fine aggregate from cooling slag for reducing drying shrinkage of mortar and concrete. In the case of rapid cooling slag fine aggregate, it was effective to reduce and restrain initial shrinkage of mortar and concrete, and compressive strength was increased through the all specimen in proportion to its replacement ratio.

• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.254-257
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• 2008

For crystalline slags, of which the viscosity rapidly increases at $T_{cv}$ due to the formation of crystalline phases, the Tcv is affected by measurement conditions. In this study, we investigated the effect of cooling rate, and alumina dissolution on the determination of $T_{cv}$. Using synthetic slag samples based on the composition of Alaska Usibelli slag, $T_{cv}$ were determined under a constant cooling rate of $2^{\circ}C$/min, and under rapid cooling with holding time to allow the slag to reach thermal and rheological equilibrium. The effect of alumina dissolution was investigated using platinum lined crucibles. The constant cooling resulted in lower $T_{cv}$ by $33^{\circ}C$ as compared to the equilibrium measurements. Under $2^{\circ}C$/min cooling, the blocking alumina dissolution resulted in lower $T_{cv}$ by $23^{\circ}C$. When the $T_{cv}$ was measured under $2^{\circ}C$/min cooling using an alumina crucible, therefore, the effects of a constant cooling is somewhat offset by the alumina dissolution effect, and bring the measured value closer to the true value.

• International Journal of Concrete Structures and Materials
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• v.5 no.2
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• pp.133-137
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• 2011

In this study, a physical and chemical properties analysis was conducted for PCSP to evaluate properties of its materials and, for comparison purpose, was also conducted for CSP. The result of experiment confirmed improvement of iron recovery rate due to introduction of rapid water-cooling equipment and greater density of exterior and interior structure through SEM observation and porosity measurement. Also, SEM, XRD and DSC-TGA analysis showed that content of f-CaO in PCSP was minuscule so it was decided that problems of material stability including f-CaO-caused bulging failure, which has been problematic, can be solved.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.48-53
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• 2003

The steel slag, a by-product which is produced on the process of manufacturing steel by refining pig iron is mainly used as road materials after aging it. It is necessary to age steel slag for long time in air because the reaction with water and free-CaO in steel slag could make the volume expanded. Due to this reason it prevents steel slag from being used as aggregate of concrete. But steel slag used in this study is controled by a air-jet method which rapidly cools substance melted at a high temperature. Rapid cooling prevents from generating of free-CaO in steel slag. In this study, it was investigated that steel slag manufactured by air-jet method affects on concrete in the freezing and thawing. As results of this study, concrete mixed with steel slag was worse in the freezing and thawing than concrete mixed with sand in spite of using air entraining agent. To obtain durability of concrete in the freezing and thawing, it is desirable to mix 50% of steel slag in concrete per unit weight of volume.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.217-222
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• 2003

The steel slag, a by-product which is produced during the manufacture of steel by refining pig iron, is mainly used as road materials after aging it. It is necessary to age steel slag for long time in air because the reaction with water and free-CaO in steel slag could make the expansion of volume. This problem prevents steel slag from being used as aggregate for concrete. But steel slag used in this study was controled by an air-jet method which rapidly cools substance melted at a high temperature. Rapid cooling prevents from generation of free-CaO in steel slag. In this study, properties of steel slag manufactured by air-jet method and mortar used it were investigated. As results of this study, free-CaO contents were controled under 1%. Mortar used this steel slag demanded to lower water contents, higher compressive strength and lower drying shrinkage than the basic mortar in the same condition.

• Resources Recycling
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• v.23 no.2
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• pp.90-97
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• 2014

The artificial dry silica used as dry aggregates in domestic is collected increasing every year. It is required drying process for the production of dry aggregates, therefore, it is main culprit of the cost up of aggregates and air pollution by using fossil fuel for the solution, it is developed alternative aggregates for the replacement of dry aggregates very ungently. In this article, the patents and papers for the recycling technology on the high-efficiency rapid cooling method of ladle furnace slag were collected and analyzed. The open patents of USA (US), European Union (EP), Japan (JP), and Korea (KR) and SCI journals from 1977 to 2013 were investigated. The patents and journals were collected using key-words and filtered by the definition of the technology. The patents and journals were analyzed by the years, countries, companies, and technologies and the technical trends were discussed in this paper.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.110-111
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• 2014

Amount of slag which is a recycled aggregate that be produced as a industrial by-product from steel production process is increasing. But there is few suggestions for usage of slag except for shaft furnace slag and studies for utilizing this are lacked. In this study, it reviews flow characteristics according to replacement ratio of rapid cooling steelmaking slag from the perspective of rheology. Replacement ratio of ps ball is used by replacing 40, 45, 50% for each binder mass.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.2
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• pp.70-77
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• 2012

The Ladle Furnace Slag, about 20% of the electric arc furnace slag, has high content of free CaO and free MgO, which generates the expansion collapse by hydration reaction. Although many researchers have been endeavoring to recycle the EAF reducing slag in construction fields, there is not found the effective recycling method up to now. However, the LFS(Ladle Furnace Slag) contains mineral composition of the system of calcium aluminate with high-reactivity. Therefore, it is possible to developed the quick setting property and the high strength at the early age by the rapid cooling. This study aimed to check the reactive minerals and predict the reactivity with water on the LFS discharged from different steel product plants. The test results show that many types of LFS has hydration reactivity and can use in construction field as a inorganic binder with the rapid setting property.

• Journal of the Korea Institute of Building Construction
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• v.11 no.5
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• pp.442-451
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• 2011

Blast furnace slag is recycled as a high value-added material, while steel slag is difficult to recycle or is recycled as a low-grade filler material due to its expansive characteristics. Its property is caused by the high content of free lime and instable steel oxides. Recently, an innovative and rapid cooling method for melting steel slag has been developed in Korea, which reduces free lime content to a minimum level and increases the stability of steel oxides. However, researches on the long-term stability are not sufficient so far. Therefore, this study, focusing on the electric arc furnace oxidizing slag in the steel slag, aims to investigate the properties of the steel slag aggregate, its long-term volume stability and the engineering strength of mortar, and using it as a fine aggregate. This study result indicated that it was possible for it to be used as concrete aggregate because the volume change of the steel slag appeared to be stable.