• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 추계 학술논문 발표대회
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• pp.56-57
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• 2016

Recently amongst Korea's construction companies there has been heightened interest in environment load reduction and resource recycling. As a result, the construction industry is examining recycled materials alternative to cement and blast-furnace slag (BS henceforth) cement, such as waste refractories and desulfurized plaster. This study analyzes the liquidity and intensity characteristics of mortar according to changes in replacement ratios of waste refractories and desulfurized plaster, used as industry by-products in mortar environments that use BS 3-type cements and circulated fine aggregate. As a result, the greater the increase in replacement ratios of desulfurized plaster, the greater the increase in liquidity and air quantity, as well as compression strength.

• 한국건설순환자원학회논문집
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• 제4권3호
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• pp.227-234
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• 2016

국내 화력발전소의 추가 증설과 관련하여 발생 부산물의 신규 사용처 연구가 필요한 실정이다. 본 연구에서는 화력발전소에서 발생되는 플라이애시와 열병합발전소에서 발생되는 열병합애시, 배연탈황공정에서 발생되는 탈황석고 등 부산물로부터 아스팔트 포장용 채움재의 KS 규격을 만족하는 채움재를 제조하였다. 제조된 혼합 채움재와 기존 석회석 채움재의 특성을 비교하고, 각각의 채움재를 사용하여 아스팔트 혼합물을 제조하는 실내실험을 통해 특성을 비교하였다. 또한 혼합 채움재와 석회석 채움재를 사용하여 아스팔트 포장 현장실험을 실시하였다. 현장실험에 사용된 아스팔트 혼합물에 대해서 실내실험과 동일하게 동적안정도, 마샬안정도, 인장강도비, 포화도, 간극률, 흐름값을 평가하였다. 실내실험 및 현장시공시험 결과 기존 석회석 채움재를 사용한 경우보다 동적안정도 및 마샬안정도, 인장강도비에서 우수한 특성을 나타내었으며, 배합설계의 최적화를 통해 기존 석회석 채움재의 특성을 만족시키는 채움재 개발 가능성을 확인하였다.

• 방사선산업학회지
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• 제10권4호
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• pp.173-179
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• 2016

Coals and coal ashes, raw materials and by-products, in coal-fired power plants contain naturally occurring radioactive materials (NORM). They may give rise to internal exposure to workers due to inhalation of airborne particulates containing radioactive materials. It is necessary to characterize radioactivity concentrations of the materials for assessment of radiation dose to the workers. The objective of the present study was to analyze radioactivity concentrations of coals and by-products at four coal-fired plants in Korea. High purity germanium detector was employed for analysis of uranium series, thorium series, and potassium 40 in the materials. Radioactivity concentrations of $^{226}Ra$, $^{228}Ra$, and $^{40}K$ were $2{\sim}53Bq\;kg^{-1}$, $3{\sim}64Bq\;kg^{-1}$, and $14{\sim}431Bq\;kg^{-1}$ respectively in coal samples. For coal ashes, the radioactivity concentrations were $77{\sim}133Bq\;kg^{-1}$, $77{\sim}105Bq\;kg^{-1}$, and $252{\sim}372Bq\;kg^{-1}$ in fly ash samples and $54{\sim}91Bq\;kg^{-1}$, $46{\sim}83Bq\;kg^{-1}$, and $205{\sim}462Bq\;kg^{-1}$ in bottom ash samples. For flue gas desulfurization (FGD) gypsum, the radioactivity concentrations were $3{\sim}5Bq\;kg^{-1}$, $2{\sim}3Bq\;kg^{-1}$, and $22{\sim}47Bq\;kg^{-1}$. Radioactivity was enhanced in coal ash compared with coal due to combustion of organic matters in the coal. Radioactivity enhancement factors for $^{226}Ra$, $^{228}Ra$, and $^{40}K$ were 2.1~11.3, 2.0~13.1, and 1.4~7.4 for fly ash and 2.0~9.2, 2.0~10.0, 1.9~7.7 for bottom ash. The database established in this study can be used as basic data for internal dose assessment of workers at coal-fired power plants. In addition, the findings can be used as a basic data for development of safety standard and guide of Natural Radiation Safety Management Act.