• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.11a
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• pp.229-230
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• 2017

This study aims to achieve an enhancement in the quality of high strength concrete through a reduction in autogenous shrinkage by supplying the moisture needed for hydration through recycled aggregates that retain high amounts of moisture. The result showed that, moisture supply increased with the higher replacement rate, autogenous shrinkage dropped by up to 60 percent. Also, compressive strength was increased by up to 10 percent.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.33-34
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• 2022

The purpose of this study was to provide basic data for applying oyster shells and egg shells as fireproof cladding materials by substituting fine aggregates for oyster shell powder and egg shell powder, and comparing strength and fire resistance performance. The reason for the high strength was thought to be that the oyster shell had higher strength than the egg shell itself, and both ESP and OSP were measured at a backside temperature of less than 500℃, so it was judged that it could be used as a fireproof coating for steel structures.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.97-98
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• 2022

In this study, conducted a Mock-up test on the use of TBC and CGS fine aggregates for the purpose of reducing the upper and lower hydration heat according to the horizontal division and punching of mass concrete. As a result of the experiment, it is judged that it will be effective in preventing temperature cracking of mass concrete when mixing the upper and lower parts and replacing CGS.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.99-100
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• 2022

This study analyzed the basic characteristics of mortar using CGS modified by pretreatment. As a result of the analysis, it was found that CGS after reforming can be partially replaced with fine aggregates to solve the existing air volume reduction problem when used, and can contribute positively in terms of securing fluidity and improving strength. Therefore, it is considered necessary to verify as a functional material of CGS through concrete durability experiments as a future task.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.78-79
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• 2021

This study compared and analyzed the fluidity and compressive strength characteristics of mortar using ferronikel slag powder and mixed slag fine aggregate as part of the study to reduce environmental load and increase recycling rate of industrial by-products.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.75-76
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• 2022

In the event of a fire in the lower space, a high temperature of 1000℃ or more and an explosive fire may occur due to the closed structural features and combustible materials. On the other hand, more than 90% of oyster shells are made of CaCO₃, and when heated to about 700℃ or higher, CaO and CO₂ is generated due to decarboxylation reaction. In this study, we try to infer the amount generated by CO₂ changing the weight of mortar using oyster shells as fine aggregates after heating. in conclusion It is considered that the smaller the particle, the greater the decarboxylation reaction and the greater the weight change.

• Journal of the Korean Geosynthetics Society
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• v.11 no.3
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• pp.19-25
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• 2012

In this study, a recycling plan for waste concrete fine aggregate as fill material was researched by investigating environmental engineering properties. It is noted that the environmental influence of waste concrete fine aggregate is little since chemical level is satisfied the waste management standard. Waste concrete fine aggregate is not suitable for materials of anti-frost layer and sub-base layer since the particle-size distribution and engineering properties are not partially satisfied the quality standard. However, waste concrete fine aggregate can be recycled as materials of anti-frost layer and sub-base layer if we improve the engineering properties by mixing bigger aggregates than maximum particle size (5 mm) more than 25 percent of total weight.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.27 no.3
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• pp.115-121
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• 2017

The degradation of the concrete due to deterioration factors, such as corrosion of steel bars, cracks and structural strength of reinforced concrete structures, is a social problem. Especially, concrete structures constructed in seawater, underground water, waste water treatment facilities and sewerage are subject to chemical attack by acid and sulphate. Therefore, this study was conducted to compare sulfated glass and fine aggregate of slag using waste glass fine powder and meta kaolin. The results showed that the slag fine aggregate showed better sulfate resistance than the river sand, and the fine powder of waste glass showed the best performance at 3 % displacement.

• The Korean Journal of Cytopathology
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• v.14 no.1
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• pp.17-21
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• 2003

Insular carcinoma of the thyroid(ICT) is an uncommon thyroglobulin-producing neoplasm, intermediate between well differentiated and anaplastic carcinoma. Only a few publications have addressed the fine needle aspiration cytologic(FNAC) findings from ICT. We experienced a case histologically diagnosed as ICT and with preoperative FNAC in a 52 - year - old woman. The FNAC displayed scanty colloid and abundant monomorphic follicular cells presented singly, in small loose aggregates, and in cohesive trabecular or acinar clusters. Intact insulae of tumor cells were also identified. Necrosis and mitosis were rare. Tumor cells showed round and monomorphic nuclei, finely granular chromatin, and inconspicuous nucleoli. When insular structure is identified in thyroid FNAC specimen, ICT should be included in the differential diagnosis. Herein we discuss and review the cytologic criteria for separation of ICT from other thyroid neoplasms.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.11a
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• pp.243-244
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• 2011

In general, magnetite or barite (density: more than 4.0ton/㎥) has been used in concrete for radiation shielding, and radiation tests have been performed to evaluate shielding performance. However, researchers have not studied concrete for radiation shielding that utilizes electric arc furnace oxidizing slag. This research aims to utilize electric arc furnace oxidizing slag which depends on reclamation as environment-friendly concrete materials by using coarse and fine aggregates of electric arc furnace slag containing 30% ferrous metal and with a density of around 3.0~3.8 ton/㎥. Accordingly, this research has judged that the high density electric arc furnace oxidizing slag aggregate can be applied to radiation shielding concrete. It has also examined the possibility of developing radiation shielding concrete utilizing electric arc furnace oxidizing slag aggregate by comparing concrete utilizing all fine and coarse aggregate of electric arc furnace oxidizing slag with concrete using magnetite.