• Title/Summary/Keyword: 생형사

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A Study on the Flowable Backfill with Waste Foundry Sand for Retaining Wall (유동특성을 이용한 폐주물사 혼합물의 옹벽뒷채움재 연구)

  • 조재윤;이관호;이인모
    • Journal of the Korean Geotechnical Society
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    • v.16 no.4
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    • pp.17-30
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    • 2000
  • The objective of this study is to evaluate the lateral earth pressure and the stability of small scale retaining wall with waste foundry sand(WFS) mixtures as a controlled low strength materials (CLSM). Three different types of WFS, like Green WFS, Hurane WFS and Coated WFS, were used in this study, and fly ash of Class F type was adopted. To evaluate the lateral earth pressure and the stability of retaining wall, two different samll scale retaining wall tests, which are called an artificially controlled strain method and a natural strain method, were carried out. In case of an artificially controlled strain method, the coefficient of lateral earth pressure, just after backfilling of WF mixtures, was around 0.8 to 1.0, and most of earth pressure was dissipated within 12 hours. In case of a natural strain method, two steps of stage constructions were employed. The mixtures of Hurane WFS and Coated WFS showed fast decrease of earth pressure due to a relatively good drainage. Judging from the sta bility of retaining wall for overturning and sliding, two steps of stage construction for 2 days were enough to finish the backfill of 6-m height of retaining wall. Also, considering the curling effect of WFS mixtures, the stability of retaining wall increased as curling time increased.

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A basic study for the rapid green sand control (신속한 생형사(生型砂) 관리(管理)를 위한 기초연구)

  • Kim, M.H.;Kwun, S.I.;Kang, C.S.;Na, D.J.
    • Journal of Korea Foundry Society
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    • v.7 no.3
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    • pp.199-206
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    • 1987
  • This paper presents experimental data for the computerization of green sand control. The results can be summarized as follows: 1. To obtain the proper compactability at the mixer, the addtion of moisture is far more efficient than the control of mixing time or addtion of clay. 2. The log R(% clay/% moisture) vs. log compactability curve moves upward as the amount of clay increases and moves downward as the amount of seacoal, dead bentonite or coked seacoal increases. 3. The ratio of dead to initial clay amount or coked to initial seacoal amount is changed according to sand to metal ratio, mainly, and according to pouring temperature, partly, at a shake out time of 12hrs.

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