• 제목/요약/키워드: Water permeability

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높은 혼합비율의 플라이 애쉬를 갖는 콘크리트의 침투성 특징에 관한 연구 (Permeability Properties of High Fly Ash Concrete)

  • 이진용
    • 콘크리트학회지
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    • 제7권4호
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    • pp.109-118
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    • 1995
  • 콘크리트의 침투성은 내구성과 밀접한 관계가 있고, 콘크리트의 내구성은 침투성 특성에 의해서 간접적으로 측정될 수 잇다. 실험 결과에 의하면 콘크리트의 침투성에서 플라이애쉬의 양이 증가할수록 (15%, 30%, 그리고45%) 침투성이 낮아졌으며, 기건양생한 콘크리트가 수중양생한 것에 비해서 월등히 높은 침투성을 보여 주었으나. 그 차이점은 플라이애쉬를 섞는 양이 많을수록 줄어 들었다. 높은 비율의 플라이애쉬(45%) 다양한 조강 시멘트를 섞어 만든 콘크리트에서도, 플라이애쉬 콘크리트가 보통(PCI)콘크리트보다 낮은 침투성을 보여주었다. 콘크리트는 양생기간이 길어짐에 따라 시멘트종류에 관계없이 침투성이 낮아졌으나, 기건양생시에는 증가하는 것을 보여주었다. 침투성 특징에서 모든 콘크리트는 물을 이용해 시험한 것이 기체를 이용해 시험한 것 보다 항상 낮은 값을 갖는다는 것이 발견되었다. 콘크리트의 침투성은 그것의 강도가 증가함으로써 줄어드는 것을 발견하였으나, 침투성의 특징은 주로 사용한 시멘트종류와 좀더 밀접한 관계가 있는 것으로 나타났다.

Permeability Characteristics of Sand- Bentonite Mixtures

  • Chang, Pyoung-Wuck;Chae, Yong-Suk
    • 한국농공학회지
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    • 제39권2호
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    • pp.26-31
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    • 1997
  • Abstract A series of permeability tests was performed on the mixtures with specific mixing rates of sand and bentonite using modified rigid-wall permeameter. Sand-bentonite mixtures were permeated by organics, ethanol and TCE. Permeability of bentonite with several mixing rates had a tendency to decrease up to initial one pore volume and permeability was thereafter converged to a constant value. When sand-bentonite mixtures was permeated by water, permeability was decreased at the beginning but it was thereafter converged to a constant. Among several mixing rates, permeability was greatly decreased at 15% of mixing rate. When sand-bentonite mixtures with 15% mixing rate was permeated by ethanol, permeability was about 10 times larger value than permeability of water. Peameability was shown greater values when permeated by TCE (TrichloroEthylene) followed by ethanol. Suitable mixing rate of sand-bentonite for a liner of waste landfills was detected.

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함수특성에 근거한 국내 풍화토의 불포화 투수곡선 추정 (Estimation of Unsaturated Permeability Function from Water Retention Characteristics for Korean Weathered Soils)

  • 김윤기;최경림;이성진;이승래;권형석
    • 한국지반공학회논문집
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    • 제26권10호
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    • pp.49-60
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    • 2010
  • 지반의 투수특성은 다양한 지반구조물의 설계 및 해석에서 중요한 지반물성이다. 특히 불포화 상태에서 모관흡수력의 영향을 받으며 모판흡수력 증가에 따라 감소하는 경향은 함수특성 변화와 유사하다. 불포화 투수계수는 실내실험을 통해 직접적으로 구하거나 함수특성곡선으로부터 유추된 이론식을 통해 간접적으로 얻을 수 있다. 본 논문에서는 국내 7개 지역에 대한 시료를 대상으로 함수특성실험과 본 연구에서 개발한 불포화 투수실험 장비를 이용하여 불포화 투수실험을 실시하였다. 지반의 함수상태를 나타내는 함수특성곡선이 불포화 투수계수와 밀접한 관련이 있으므로 함수특성곡선으로부터 불포화 투수곡선을 유추하는 여러 모텔 결과와 실험결과를 비교하였다. 그러나 기존의 추정방법은 국내지반의 투수특성을 잘 표현하지 못하고 있다. 따라서 국내 풍화토의 불포화 투수곡선을 정확히 유추하기 위하여 보정계수를 적용하여 FXK-M 투수모델을 제시하였고 보정계수를 함수특성곡선의 공기함입치로부터 산정할 수 있는 수식을 제안하였다.

Dynamic evolution characteristics of water inrush during tunneling through fault fracture zone

  • Jian-hua Wang;Xing Wan;Cong Mou;Jian-wen Ding
    • Geomechanics and Engineering
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    • 제37권2호
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    • pp.179-187
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    • 2024
  • In this paper, a unified time-dependent constitutive model of Darcy flow and non-Darcy flow is proposed. The influencing factors of flow velocity are discussed, which demonstrates that permeability coefficient is the most significant factor. Based on this, the dynamic evolution characteristics of water inrush during tunneling through fault fracture zone is analyzed under the constant permeability coefficient condition (CPCC). It indicates that the curves of flow velocity and hydrostatic pressure can be divided into typical three stages: approximate high-velocity zone inside the fault fracture zone, velocity-rising zone near the tunnel excavation face and attenuation-low velocity zone in the tunnel. Furthermore, given the variation of permeability coefficient of the fault fracture zone with depth and time, the dynamic evolution of water flow in the fault fracture zone under the variable permeability coefficient condition (VPCC) is also studied. The results show that the time-related factor (α) affects the dynamic evolution distribution of flow velocity with time, the depth-related factor (A) is the key factor to the dynamic evolution of hydrostatic pressure.

Efficient Optimum Design of Reinforced Concrete Structures using the Mixed-Discrete Optimization Method

  • Kim, Jong-Ok
    • 한국농공학회지
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    • 제39권2호
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    • pp.32-43
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    • 1997
  • Abstract A series of permeability tests was performed on the mixtures with specific mixing rates of sand and bentonite using modified rigid-wall permeameter. Sand-bentonite mixtures were permeated by organics, ethanol and TCE. Permeability of bentonite with several mixing rates had a tendency to decrease up to initial one pore volume and permeability was thereafter converged to a constant value. When sand-bentonite mixtures was permeated by water, permeability was decreased at the beginning but it was thereafter converged to a constant. Among several mixing rates, permeability was greatly decreased at 15% of mixing rate. When sand-bentonite mixtures with 15% mixing rate was permeated by ethanol, permeability was about 10 times larger value than permeability of water. Peameability was shown greater values when permeated by TCE (TrichloroEthylene) followed by ethanol. Suitable mixing rate of sand-bentonite for a liner of waste landfills was detected.

전기영동 겔과 녹차성분에 대한 환원전리수의 침투력과 용해력 (Permeability and Dissolvability of Cathodic Electrolyzed Water for Electrophoretic Gel and Green Tea Components)

  • 류근걸;이윤배;이종권;이미영
    • 한국산학기술학회논문지
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    • 제6권1호
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    • pp.87-93
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    • 2005
  • 본 연구에서는 전기영동 겔에 대한 환원전리수의 침투력과 녹차성분에 대한 환원전리수의 용해력을 일반 물과 서로 비교하였다. 환원전리수로 제조한 CBB-R 염색시약으로 polyacrylamide 겔 상에서 단백질을 다양한 시간 동안 염색한 후, 증류수로 제조한 CBB-R 염색시약에 의한 염색강도와 서로 비교하였다. 그 결과 환원전리수로 제조한 CBB-R 염색시약은 증류수로 제조한 CBB-R 염색시약보다 먼저 단백질을 강하게 염색시켰다. 뿐만 아니라 $25^{\circ}C$에서 환원전리수는 일반 물에 비하여 녹차성분에 대해 극히 탁월한 용해력을 나타내었다. 이러한 결과는 환원전리수가 일반 물보다 침투력과 용해력이 매우 강력하다는 것을 보여준다.

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무기질 폴리머계 흡수방지재를 도포한 모르터의 발수성능 평가에 관한 실험적 연구 (An Experimental Study on the Water Repellent Property of Mortar Applied Water Repellent Agent of Inorganic Polymer Type)

  • 김영삼;양승도;유재강;오상근
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2002년도 학술논문발표회
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    • pp.31-36
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    • 2002
  • Recently, more interests in surface treatment of structure with water repellent agent are steadily increased, But, investigation of its properties such as protection, durability, morphology of micro structure is not sufficient. Therefore, This paper is aimed for the investigation of water repellent property and change of morphology of micro pores in mortar that is treated by water repellent agent(Inorganic polymer based material). Water repellent property, water absorption coefficient, air permeability, porosity and the observation of micro structure was investigated in different water repellent agent type. The test results indicated that water repellent treated mortar showed low absorption coefficient and air permeability(breathing effect). This is why inorganic polymer is coated at the wall of capillary and micro pores, also, the volume of micro pore is reduced without the change of morphology in micro structure.

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DC 마그네트론 스퍼터로 증착한 flexible OLED용 IZO 박막의 기계적 특성과 투습특성에 미치는 반응성 가스 첨가의 효과 (Effects of Reactive Gas Addition on the Mechanical Property and Water Permeability of IZO Films Deposited by DC Sputtering for Application to Flexible OLED)

  • 천고은;이동엽;조영래;송풍근
    • 한국표면공학회지
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    • 제40권6호
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    • pp.245-249
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    • 2007
  • Amorphous IZO films were deposited on PET substrate by DC magnetron sputtering without substrate heating. In order to investigate effect of reactive gas addition on film properties, 0.2-0.4% of $H_2$ or $O_2$ gas was introduced during the deposition. Deposited IZO films were evaluated with mechanical property, electrical property, and water permeability. In the case of $H_2$ gas addition, mechanical property showed clear degradation compared to $O_2$ gas. In the case of $O_2$ gas, water permeability of the IZO film was increased compared to $H_2$ gas which could be attributed to the low adhesion of the film caused by bombardment of high energy negative oxygen ion. As a result, it is confirmed that water permeability of the film could be strongly affected by adhesion of the film.

Characteristics of waterflood at low rate in low permeability sandstones based on the CT scanning

  • Mo, S.Y.;Lei, Q.;Lei, G.;Gai, S.H.;Liu, Z.K.
    • Geosystem Engineering
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    • 제21권6호
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    • pp.344-351
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    • 2018
  • It is reported that the flooding rate in low permeability sandstones is low and the oil recovery is hard to increase after water breakthrough. Understanding characteristics of waterflood is hence important for the recovery improvement. In this work, flooding tests on low permeability sandstones were conducted. The corresponding flooding characteristics were investigated by means of CT scanning and Nuclear Magnetic Resonance. Effects of irreducible water and different rates were also discussed in detail. Experimental results reveal a piston-like displacement at a low rate in low permeability samples. The saturation profile is steep and almost vertical to the forward direction. The results at a low rate confirm that once water broke through, increasing the flooding rate or flooding time can hardly reduce the remaining oil inside the sample. It is probably due to the high pore-throat ratio proven by rate-controlled mercury. Results also confirm that the presence of initial water enhanced sweep efficiency substantially. On one hand, because water had previously occupied the small pores, the subsequent oil can only invade relatively large pores and became more movable. On the other hand, stable collars can not form due to the steep front, which may suppress the snap-off.

콘크리트 표면처리방법에 따른 금속용사 피막의 투수성 평가에 관한 실험적 연구 (An Experimental Study on the Permeability Evaluation of Metal Spray System by Concrete Surface Treatment)

  • 박진호;이한승
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2015년도 추계 학술논문 발표대회
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    • pp.34-35
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    • 2015
  • Recently, introduction of Advanced water treatment facilities has been increasing due to serious domestic water pollution. Ozone is a strong oxidizing materials in the advanced water treatment facilities. However, due to such a strong oxidation, Ozone eroded waterproofing/corrosion on the concrete surface and caused performance degradation. Therefore, in this study, permeability experiment of metal spraying system by concrete surface treatment was conducted.

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