• Title/Summary/Keyword: 주물고사

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Characteristics of Asphalt Concrete using Waste Foundry Sand (주물고사 첨가 아스팔트 콘크리트의 특성에 관한 연구)

  • Kim, Kwang-Woo;Ko, Dong-Hyuk;Choi, Dong-Chon;Kim, Sung-Won;Kim, Joong-Yul
    • International Journal of Highway Engineering
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    • v.3 no.4 s.10
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    • pp.105-116
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    • 2001
  • This study was performed to evaluate the characteristics of waste foundry sand (WFS) and the asphalt mixture made of a foundry waste sand. To estimate the applicability of WFS, chemical and physical properties were measured by XRF(X-ray fluorescent), and SEM(Scanning electronic microfilm). To improve the stripping resistance of WFS asphalt mixture, anti-stripping agents (a hydrated lime and a liquid anti-stripping agent) were used. To improve tensile properties and durability of WFS asphalt concrete mixture, LDPE(low-density polyethylene) was used as an asphalt modifier Marshall mix design, indirect tensile strength, tensile strength ratio(TSR) after freezing and thawing, moisture susceptibility and wheel tracking tests were carried out to evaluate performance of WFS asphalt concrete. Comparing with conventional asphalt concrete, WFS asphalt concretes showed similar or the better qualify in mechanical properties, and satisfied all specification limits. Therefore, it Is concluded that waste foundry sand can be recycled as an asphalt pavement material.

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Studies on the Effect of Heptachlor Residues in Soil on the Growth of Hop ;I. Phytotoxic Symptom of Heptachlor Residues in Hop (Heptachlor 토양잔류가(土壤殘留) Hop 의 생육(生育)에 미치는 영향(影響);제(第)1보(報) Heptachlor에 의(依)한 Hop 피해양상(被害樣相))

  • Park, Kyeong-Yeol;Lee, Dong-Woo;Park, Chang-Kyu;Han, Dae-Sung
    • Korean Journal of Environmental Agriculture
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    • v.1 no.2
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    • pp.99-104
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    • 1982
  • These studies were carried out to investigate the damage of root rot of hop by heptachlor residues in soil at nine farm fields and pot experiment for two years from 1980 to 1981. 1) Pot experiment results indicated that root rot of hop occurred in farm field were caused by heptachlor phytotoxicity. 2) The damage of root rot of the hop was found by heptachlor residues in soil. Hop root in the low concentration of heptachlor was turned to brown mottle, and then rotted. In high concentration, the hop root was decreased in number, blocked in growth, and resulted to greyish change with death. 3) Hop vine damaged by heptachlor was hardened and broken with ease. 4) Heptachlor epoxide which was inferred to be the main cause of hop root rot gave the damage to hop at 0.009 ppm reisdues in soil. 5) The phytotoxicity of heptachlor was proved to last for 10 years or more in this study.

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