• Journal of the Korean Crystal Growth and Crystal Technology
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• v.28 no.6
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• pp.256-262
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• 2018

A great amount of fly ash, which is a waste from a thermal power plant, has not been appropriately recycled until now. Landfill of flay ash causes environmental pollution and enormous economic costs. In this study, manufacturing of architectural ceramic tile was investigated replacing fly ash with clay raw material. The properties of porcelain tile was analyzed after manufacturing porcelain tile with mineral based glaze and fast firing process. In particular, the effect of the fly ash addition on the properties of ceramic tile was investigated by increasing the amount of limestone addition. Porcelain tile with fly ash showed excellent bending strength, water absorption, warping and abrasion resistance. However, a significant decrease in durability was observed through the autoclave test. Addition of limestone increased the water absorption, twisting and hydration expansion of the ceramic tile, but it was confirmed that the durability of the ceramic tile with fly ash was greatly improved. In conclusion, recycled architectural ceramic tiles, which can meet domestic construction standards, could be manufactured with the addition of fly ash and limestone.

• Journal of the Korean GEO-environmental Society
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• v.22 no.3
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• pp.5-13
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• 2021

Due to population growth and industrial development, the amount of industrial waste is increasing every year. In particular, in a thermal power plant using finely divided coal, a large amount of coal ash is generated after combustion of the coal. Among them, fly ash is recycled as a raw material for cement production and concrete admixture, but about 20% is not utilized and is landfilled. Due to the continuous reclamation of such a large amount of coal ash, it is required to find a correct treatment and recycling plan for the coal ash due to problems of saturation of the landfill site and environmental damage such as soil and water pollution. In recent years, the use of a fluid embankment material that can exhibit an appropriate strength without requiring a compaction operation is increasing. The fluid embankment material is a stable treated soil formed by mixing solidifying materials such as water and cement with soil, which is the main material, and has high fluidity before hardening, so compaction work is not required. In addition, after hardening, it is used for backfilling or filling in places where compaction is difficult because higher strength and earth pressure reduction effect can be obtained compared to general soil. In this study, the possibility of use of fluidized soil using high water content cohesive soil and coal ash is considered. And it is intended to examine the flow characteristics, strength, and bearing capacity characteristics of the material, and to investigate the effect of reducing the earth pressure when applied to an underground burial.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.6
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• pp.180-188
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• 2020

To replace Japanese coal ash used in the domestic cement production and to recycle large quantities of domestic pond ash, it is essential to develop the technologies for quality control of cement by using the domestic pond ash. Thus, in this study, the feasibility of using the pond ash as a raw material for cement was investigated through chemical composition and microstructure analysis. As a result, most of the domestic pond ash contained slightly more Fe2O3, chloride, and unburned carbon contents than Japanese coal ash. In particular, the contents of chloride were considerably low in the pond ash that was transferred to fresh water or collected from surface of landfill area. However, since circulating fluidized bed boiler coal ash had relatively high SO3 contents causing durability problems of cement, it was not suitable for use as a raw material for cement. Thus, to replace Japanese coal ash with the domestic pond ash, it is necessary to introduce the adjustment of mixture proportion of cement raw materials and the process of removing chloride in the pond ash.

• Journal of the Korean Geotechnical Society
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• v.38 no.12
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• pp.67-78
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• 2022

In this study, the measurement results of the coastal deep soft ground buried in the upper part of the dredged clay were analyzed and compared with the current specification standards. Based on the results, a suitable proposal was suggested for the selection, installation, data arrangement, and analysis of each instrument used in the deep soft ground improvement construction. The pore water pressure meter has a range of 1.5 times or more of the expected measurement range, considering the field conditions of the soft ground. The groundwater level meter installed in the horizontal drainage layer checks the change in the groundwater level during the embanking as well as the performance of the catchment well and the horizontal drainage layer. Therefore, it is important to manage so that the groundwater level exists inside the horizontal drainage layer during embanking. It is enough to install the inclinometer in the gravel layer below the soft ground or weathered rock with an N value of 40 or more for the deep soft ground. It seems desirable to install a screw type for differential settlement meter. However, the screw type should not settle due to its own weight. Considering that it is a dredged landfill where subsidence occurs significantly, it is sufficient to manage the tolerance of leveling at about 10 mm (L is the one-way distance (km)).

• Journal of the Korean Geosynthetics Society
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• v.22 no.2
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• pp.63-70
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• 2023

Most of the industrial complexes and housing complexes in Busan and Gyeongnam were constructed by developing mountainous areas, except for some landfill areas. During the development process, the surplus soil for site development was mainly used as the embankment material. In the field, however, even if the material of the material changes during the embankment work for site development, for convenience reasons such as construction period and site conditions, the material property test and compaction test are not additionally conducted for the embankment material, and quality control is conducted. In this study, physical property tests and compaction tests were conducted on surplus soils in mountainous areas in Busan, GyungNam Province and then regression analysis was performed on the data. In addition, a comparative analysis was conducted along with existing studies in Korea. The surplus soils at the sites in Busan and Gyeongnam were mainly weathered soils of granites, and were classified into clayey sand (SC) and silty sand (SM). As a result of regression analysis of the compaction characteristics according to the content of coarse and fine soils, the correlation between them was very high. Using the relational formula as a result of this study, it will be very useful for compaction management of the surplus soils in the field.

• Journal of Environmental Impact Assessment
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• v.33 no.3
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• pp.131-141
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• 2024

The environmental impact assessment have been played important role for sustainable development of the country. Meantime, various studies have been conducted for scientific and effective environmental impact assessment. Howeverthe quantitative data such as regional distribution status and development characteristics according to the type of development project, environmental changes due to development projects, and spatial-temporal changes are insufficient, currently. In this study, we investigated the eco-friendliness of major development projects (industrial complex, urban development, tourist complexes, and waste disposal equipments) by integrating the EA-INDEX of each development projects which were reported by prior researches. As a result, we found that the eco-friendliness of development projects tended to gradually increase overtime due to the increase in eco-friendliness in the protection of living environment sector. The protection of living environment sector was a major factor in the the eco-friendliness of industrial complexes and urban development projects. In the case ofroad construction, landfill and tourist complex development projects, the natural environment conservation sector was a major factor in the eco-friendliness of the project. As a result of analyzing the eco-friendliness of development projects by local government, the eco-friendliness of development projects promoted and implemented in Ulsan, Jeonnam, and Gwangju was higher compared to other regions, and it was relatively low in Daejeon, Gyeongnam, and Daegu. This study is considered to be significant in that it conducted a quantitative analysis of the eco-friendliness of development projects carried out over a relatively long period of time throughout South Korea by dividing them by year and local government.