• Journal of the Korean Society of Safety
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• v.15 no.4
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• pp.127-133
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• 2000

The incomplete treatment of the swinery wastewater is one of the major factors of the river contamination resulting from an eutrophication. Even through many treatments were considered to reduce the contamination of the river by the swinery wastewater, the most effective treatment was not developed yet. Therefore, this project was focused on the development of the treatment that was a low cost and a high efficiency using a steel-making slag. The swinery wastewater was passed through a U-type tube packing the slag in the laboratory. And the swinery wastewater was cleaned effectively in the laboratory experiment. Based on these laboratory results, the treatment facility in a stock farm was constructed to confirm the effect of slag on the first-treated swinery wastewater. After the treatment of the first-treated swinery wastewater through the slag, the water quality of the river was improved and the biodiversity was increased.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1463-1474
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• 2008

In order to investigate stabilization effect and sustainability on As-contaminated farmland soils which were affected the abandoned mine site and stabilized by zerovalent iron(ZVI) and industrial by-products, batch-scale and pilot-scale tests were carried out. In batch tests, ZVI and industrial by-products(blast furnace slag, steel refining slag and oyster shell powder) were used in treatment materials to reduce the As leaching. Industrial by-products were mixed with As-contaminated soils, in the ratio of 1%, 3%, 5% and 7% on the weight base of dried soil. The results of batch-scale tests was shown that the reduction of As concentration was observed in all samples and it was expected that ZVI and steel refining slag were more effective than other treatment materials to stabilize As compounds. In pilot-scale tests, columns were filled with untreated soils and treated soils mixed with ZVI and steel refining slag in the same mixing ratio of 3%. Distilled water was discharged into the columns with the velocity of 0.3 pore volume/day. During the test, pH, EC, Eh and As concentration were measured in the regular term(1pore volume). after six months, pilot-scale tests were retested to investigate sustainability of treatment materials. As a result, It was shown that the leachate from control column was continuously released during the test period and its concentration was greater than $100ug{\cdot}L^{-1}$ which was exceeded the national regulation of water discharged to river or stream ($50ug{\cdot}L^{-1}$). On the other hand, soil treated with ZVI and steel refining slag showed that the concentrations of leachate were lower than national regulation of water discharged to river or stream. Therefore it was expected that ZVI and steel refining slag could be applied to the farmland site as the alternative treatment materials.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.4
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• pp.404-408
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• 2003

This paper discusses the physical properties of permeable high quality concrete using blast furnace slag or steel slag as a part of aggregate. In the case of steel slag, aging treatment was adopted to prevent the volume expansion. With high range water reducing agent, the concrete using slag aggregate showed compressive strength up to 24MPa at the age of 28 days and the water permeability of the concrete was over the level of 0.1 m/s in this experiment. Also, there was no expansion problem in the concrete substituted with aged slag as a part of aggregate.

• Korean Journal of Metals and Materials
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• v.46 no.10
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• pp.662-671
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• 2008

The behavior of hydrogen in the steel making process was investigated. The relation between the composition of ladle slag and hydrogen concentration in molten steel was considered. The hydrogen distribution ratio between ladle slag and molten steel was increased with increasing basicity of the slag; it was about 20 when the basicity of slag was 15. Hydroxyl capacity measured from the hydrogen distribution ratio between slag and the molten steel was comparatively corresponding to the value of hydroxyl capacity measured by the equilibrium reaction of slag and $H_2O$ gas. However, it is considerably different from the value calculated by regular solution model. The influence of hydrogen on a sticking type breakout is considered. The effect of hydrogen and $H_2O$ gas on the crystallization behavior of mold powder was investigated by DHTT (Dual hot thermocouple technique). As a result, it was proved that mold powder could be crystallized by $H_2O$ gas in the atmosphere. Therefore, it is concluded that $H_2O$ gas in the atmosphere can be a possible cause of the sticking type breakout that occasionally occurs in the continuous casting process.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.453-458
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• 2001

Copper slag is produced about 700,000 tons annually though copper refining process in Korea. In the paper, a laboratory investigation was carried out to estimate the geotechnical properties of copper slag and examine the feasibility of using the copper slag as a substitute for conventional construction materials and the improvement of the soft clay deposit. The specific gravity of copper slag is 3.45, and pH is 7.83. And the size distribution of the copper slag is well graded, so usage of copper slag will be extended in Geotechnical engineering fields. Copper slag has the permeability of 3.502${\times}$10￣$^2$cm/sec, which is satisfied with the criterion of sand drainage materials.. At the same time, it is thought to be suitable material for sand mat since it meets JIS of grain size distribution. The content of CaO from steel slag is about 40 percent while that of CaO from copper slag is about 5 percent. Based on this fact, copper slag has less hardening property compared to steel slag. Therefore, copper slag can be used as vertical drains, filters, and sand mats for improving the soft deposit.

• Resources Recycling
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• v.17 no.1
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• pp.73-79
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• 2008

Along with the increased social infrastructures and reconstruction, the demand for aggregate, which is used in concrete, has rapidly increased. However, there are problems due to the exhaustion of natural aggregate resources, and strict restrictions. In this study, the possibility of using rapid chilled steel slag as a substitutive material of fine aggregate is determined from the property test and mechanical test for the concrete that is made with rapid chilled steel slag, which highly decreases the free CaO, the main problem of the steel slag.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.594-601
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• 2021

In order to expanding of the use of steel slag, a by-product of steel industry, as a road paving construction material, this present study confirmed the possibility of the rust formation of steel slag aggregate and evaluated the durability performance and the noise reduction characteristics of asphalt concrete mixture. As a result of conducting the rust formation test of aggregate, no rust was observed in both aggregate, so it is judged that the possibility of rust formation in the actual road water environment is very low. As a result of performing the moisture resistance test, all mixtures showed a tensile strength ratio exceeding 85%, satisfied the standard as asphalt mixture. In addition, the sound absorption coefficient of the steel slag aggregate mixture was measured to be higher than that of the general aggregate mixture. Accordingly, it is speculated th at th e steel slag aggregate mixture can more effectively respond to road noise reduction than the general mixture.

• Journal of the Korea Concrete Institute
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• v.19 no.5
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• pp.549-555
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• 2007

Although blast furnace slag has been widely used in concrete as a cementitious admixture or aggregate for many years, the slowly cooled steel slag is not used in concrete but mainly in road. Its use in concrete operates problem such as the lack of volume stability due to high free CaO content, which can be potentially hazardous in concrete. However, the rapidly cooled steel slag by atomization has a low free CaO content, a high density, and a spherical shape, so it is expected to use in concrete so much. This paper is to understand the probability that the rapid cooled steel slag can replace the silica sand used as aggregate in the epoxy mortar. We did the experimental study on the properties of the epoxy mortar having various replacement proportion of rapidly cooled steel slag. This study shown that increasing content of the rapidly cooled steel slag in epoxy mortar lead to increase largely the passing time of nozzle by O-lot, compressive strength and flexural strength. However except the flow is almost same level. So we understand that the rapidly cooled steel slag has positive effect on increasing of properties in epoxy mortar.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.3-4
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• 2014

There is high probability of steel corrosion on the reinforced concrete exposed to marine environment by penetration of chloride ion. When making concrete structure with slag as admixture in marine environment, salt damage can be prevented. Therefore, this paper presents experimental results of steel corrosion resistance of slag concrete considering marine environment through half-cell potential method which is one of the nondestructive test. As a result of half-cell potential experiment, it was assumed that every specimen exposed to marine environment was not corroded, and as a result of destroying specimens, it was confirmed that there was no corrosion in specimens.

• Advances in concrete construction
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• v.14 no.5
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• pp.331-339
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• 2022

Geopolymer concrete (GPC) is one of the best substitute materials for conventional concrete in construction. The conventional concrete provided by Portland cement has a detrimental influence on the environment during its production. In this study, the bond strength, which is an important structural property, of deformed steel bars with slag-based GPC was measured. In accordance with the ASTM C234 procedure, bond strength was measured on 18 specimens of slag-based GPC with three sizes of steel bars and different embedded lengths. Two groups of GPC specimens with different compressive strengths, which were cured under ambient conditions, were tested. The results indicated that the bar diameter has a great effect on the bond strength, and the bond strength behavior of the slag-based GPC is comparable with that of conventional concrete. The ACI-318 Code for the bond strength of ordinary Portland cement concrete can be used conservatively to determine the bond strength of the GPC reinforced with deformed steel bars.