• 제목/요약/키워드: Strength Coefficient

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대형직접전단시험을 이용한 조립재료의 전단거동 특성 (II) (Characteristic of Shear Behavior of Coarse Grained Materials Based on Large Scale Direct Shear Test (II))

  • 이대수;김경열;홍성연;황성춘
    • 한국지반공학회논문집
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    • 제22권4호
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    • pp.51-59
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    • 2006
  • 본 고에서는 선행연구(홍성연, 2004)에서 개발한 대형직접전단시험기를 이용하여 조립질 토목재료의 시험밀도와 균등계수의 크기가 전단강도에 주는 영향을 분석하였으며, 아울러, 각 수직응력별로 한계상태에서 조립재료가 갖고 있는 마찰계수를 Wood(1998)가 제안한 방정식을 이용하여 산출하였다. 시험에 사용한 재료는 경상과 전라지역 석산에서 생산중인 조립재료이다. 시험결과 시험밀도 $2.10g/cm^3$의 전단강도의 크기가 $1.85g/cm^3$의 값보다 상대적으로 크게 나타났으며, 균등계수는 상대적으로 10.0보다 5.0일때 더 큰 전단강도를 갖는 것으로 나타났다. 한편, 조립질 토목재료가 갖고 있는 한계상태에서의 마찰계수는 각 시험조건별로 $1.0{\sim}1.6$의 범위로 나타났다.

폐유리분말과 재생골재를 사용한 포장용 투수성 폴리머 콘크리트의 공학적 성질 (Engineering Properties of Permeable Polymer Concrete for Pavement using Powdered Waste Glass and Recycled Coarse Aggregate)

  • 성찬용;김태호
    • 한국농공학회논문집
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    • 제53권6호
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    • pp.59-65
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    • 2011
  • This study was performed to evaluate the compressive and flexural strength, void ratio and permeability coefficient used powdered waste glass, $CaCO_3$, recycled coarse aggregate and unsaturated polyester resin to find optimum mix design of permeable polymer concrete for pavement. The compressive and flexural strength of permeable polymer concrete for pavement using powdered waste glass were in the range of 16.8~19.7 MPa and 4.7~6.1 MPa, respectively. it was satisfied the regulation of permeable concrete for pavement (18 MPa and 4.5 MPa). The void ratio and permeability coefficient were decreased with increasing the powdered waste glass, respectively. The void ratio and permeability coefficient were satisfied national regulation of permeable concrete for pavement (8 % and $1{\times}10^{-2}$ cm/s). In addition, this study found out that required amount of binder was decreased with increasing the powdered waste glass. This fact is expected to have economical effects during the use of powdered waste glass in the manufacture of permeable polymer concrete for pavement. Accodingly, the powdered waste glass can be used for permeable concrete material.

콘크리트 크리프의 확률론적 거동 해석 (The Analysis of Statistical Behavior in Concrete Creep)

  • 김두환;박종철
    • 한국구조물진단유지관리공학회 논문집
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    • 제5권1호
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    • pp.237-246
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    • 2001
  • This study is to measure the creep coefficient by 3 days, 7 days and 28 days in the age when loading for the quality assessment of $350kgf/cm^2$ in the high-strength concrete. And it is to analyze the behavior of creep coefficient by applying the experimental data though the compressive strength test, the elastic modulus test and the dry shrinkage test to the ACI-209, AASHTO-94 and CEB/FIP-90, the prediction mode, and the basis of concrete structural design. Also it is to analyze the behavior of short-term creep coefficient during 91 days in the age when loading through the experiment by using the regression analysis, the statistical theory. As applying it to the long-term behavior during 365 days and comparing with the creep prediction mode and examining it, the result from the analysis of the quality of the concrete is as follows. As the result of comparison and analysis about the ACI-209, AASHTO-94 and CEB/FIP-90, the prediction mode, and the basis of concrete structural design, the normal Portland cement class 1 shows the approximate value with the prediction of GEE/PIP-90 and the basis of concrete structural design, but in case of the prediction of ACI-209 and AASHTO-94, there would be worry of underestimation in the application.

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투수성 콘크리트의 강도개선에 관한 연구 (A Study on the Improvements of Strengths of Water-Permeable Concrete)

  • 은재기;이철웅;김완기;조영국;소양섭
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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    • pp.307-312
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    • 1999
  • The purpose of this study is to ascertain the strength properties of water-permeable concrete with redispersible polymer powder, silica fume and polypropylene fibers. The water-permeable concrete using rediapersibel polymer powder with a water-cement ratio of 25%, polymer-cement ratios of 0 to 10%, silica fume contents of 0 to 10% and fiber contents of 0 to 1.5% are prepared, and tested for flexural strength, compressive strength and water permeability. From the test results, improvements in the strength properties of the water-permeable concrete due to the addition of the redispersible polymer powder, silica fume and fibers are discussed. It is concluded from the test results that the superior flexural and compressive strengths of water-permeable concretes are obtained at a propylene fiber content of 1.0% with a void filling ratio of 50%. And, the water-permeable concrete having a flexural strength of 15.6~28.4kgf/$\textrm{cm}^2$, a compressive strength of 63.5~120.6kgf/$\textrm{cm}^2$, and a coefficient of permeability of 1.14~1.70cm/s at a void filling ratio of 30% can be prepared. Also water-permeable concrete having a flexural strength of 35.6~57.9kgf/$\textrm{cm}^2$, a compressive strength of 164.0~290.0kgf/$\textrm{cm}^2$, and a coefficient of permeability of 0.19~1.04cm/s at a void filling ratio of 50% can be prepared in the consideration of the mix proprotioning factors.

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폐기물을 이용한 고화처리토의 차수효과 (The Permeability Characteristics of Solidified Soil Using Wastes)

  • 김인배;;안진선
    • 한국환경보건학회지
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    • 제30권5호
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    • pp.388-394
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    • 2004
  • Seaweed waste(SWW) was used to improve the liner effect in recycling of dredged soil as the landfill liner. It was found that the compressive strength became somewhat lower when SWW was added than that was when Ordinary Port-land Cement(OPC) only was added. The permeability coefficient, however, became lower in this case which showed the lowest permeability coefficient when the addition of SWW was one percent. Hence, to comply with the regulations for the compression strength and permeability coefficient of landfill liner, the addition of OPC should be over eight percent and that of seaweed waste one percent. The results of leaching test showed that the solidified material was not against the laws of waste control, so it is possible to use as the landfill liner and to expect sufficient economic effects because wastes such as dredged soil and seaweed can be recycled.

폐유리분말을 충전재로 사용한 포장용 투수성 폴리머 콘크리트의 공학적 성질 (Engineering properties of permeable polymer concrete for pavement using powdered waste glass as filler)

  • 성찬용;김태호
    • 농업과학연구
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    • 제38권1호
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    • pp.145-151
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    • 2011
  • This study was performed to evaluate the void ratio, compressive and flexural strength, and permeability coefficient used powdered waste glass, $CaCO_3$, recycled coarse aggregate and unsaturated polyester resin to find optimum mix design of permeable polymer concrete for pavement. The void ratio and permeability coefficient of permeable concrete for pavement was decreased with increasing the powdered waste glass, respectively. The compressive strength and flexural strength was increased with increasing the powdered waste glass, respectively. In addition, this study found out that required amount of binder was decreased with increasing the powdered waste glass. This fact is expected to have economical effects during the use of powdered waste glass in the manufacture of permeable polymer concrete for pavement. Therefore, powdered waste glass and recycled coarse aggregate can be used for permeable polymer pavement.

섬유보강 포러스 콘크리트의 공극률과 투수계수 특성에 관한 연구 (A Study on the Void Ratio and Permeability Coefficient Properties of fiber Reinforced Porous Concrete)

  • 김정환;조광연;이준;박승범
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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    • pp.677-682
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    • 2000
  • Porous concrete is defined as d type of concrete for which the fine aggregate component the matrix is entirely omitted. Although it had been used as a building material in Europe for over 60 years, low strength and high void ratio limited its application in the past. In recent years, however high void ratio of concrete has been recognized again and can be used as an environmental conscious material, for example, parking lots, draining light-traffic-volume pavements and as sea water purifying material. The result of an experiment on the void ratio of fiber reinforced porous concrete and its influence on the compressive strength and permeability relationship of concrete are reported in this paper. One-sized coarse aggregate of 5-10mm, and three absolute content of fiber(steel fiber, polyprophylen fiber) were used. The result of measured void ratio, permeability coefficient and compressive strength show a small variation. Void ratio, permeability coefficient and compressive strength of fiber reinforced porous concrete depend on contents of fiber and absolute volume ratios of paste to aggregate.

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Reliability based partial safety factor of concrete containing nano silica and silica fume

  • Nanda, Anil Kumar;Bansal, Prem Pal;Kumar, Maneek
    • Computers and Concrete
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    • 제26권5호
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    • pp.385-395
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    • 2020
  • The influence of combination of nano silica and silica fume, as partial cement replacement materials, on the properties of concrete has been studied through the measurement of compressive strength. The compressive strength of concrete in terms of mean, standard deviation and with-in-test coefficient of variation related to the variation in the nominated parameters have also been developed. The compressive strength data developed experimentally has been analyzed using normal-probability distribution and partial safety factors of composite concretes have been evaluated by using first order second moment approach with Hasofer Lind's method. The use of Nano silica and silica fume in concrete decreases the partial safety factor of concrete i.e., increase the reliability of concrete. The experimental results show that the properties of concrete having nano silica and silica fume in combination were better than that of a plain concrete. The SEM test results showing the level of Ca(OH)2 in plain concrete and consumption level Ca(OH)2 of concrete containing nano silica & silica fume have also been presented.

현장적용 투수성 콘크리트의 배합조건 결정에 관한 실험적 연구 (A Study on the Determination of mix Proportion of Water-Permeable Concretes for Site Application)

  • 김봉찬;은재기;김완기;소양섭
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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    • pp.130-135
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    • 2000
  • The purpose of this study is to examine the physical properties of water-permeable concretes. The water-permeable concrete with cement-aggregate ratios of 1:3.5 to 1:6.0 and two type of coarse aggregate size of 8~13 and 13~18mm used OPC(ordinary portland cement) as a binder and superplasticizer are prepared, and then tested for flexural strength, compressive strength, compressive strength, continuous void percentage and coefficient of water permeability. It is concluded from the test result that the superior flexural and compressive strengths, coefficient of water permeability and continuous void percentage of water-permeable concretes that use OPC were obtained at cement-aggregate ratios of 1:3.2, 1:6.0 respectively, The water-permeable concretes with coarse aggregate of 8~13 and 13~18mm size used OPC as a binder havinga flexural strength of 24.81~45.56kgf/$\textrm{cm}^2$, 21.99~40.62kgf/$\textrm{cm}^2$, a compressive stength of 93.63~ 242kgf/$\textrm{cm}^2$, 114.8~191.7.kgf/$\textrm{cm}^2$, a coefficient of permeability of 0.59~1.85kgf/$\textrm{cm}^2$, 0.73~ 2.25kgf/$\textrm{cm}^2$, and a continuos void percentage of 16.6~26.32%, 13.52~24.35% respectively during 28 curing days.

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입도분포가 액상화 저항강도에 미치는 영향에 관한 실험적 연구 (Experimental Study on the Effect of Particle Size Distribution of Soil on the Liquefaction Resistance Strength)

  • 서경범;최문규;김수일;박인준
    • 한국지반공학회논문집
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    • 제21권7호
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    • pp.13-20
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    • 2005
  • 본 연구에서는 입도분포가 액상화 저항강도 및 동적물성치에 미치는 영향을 실험적으로 검증하였다. 우리나라 준설매립토의 입도분포 조사를 통해 준설매립토의 보편적인 평균입경 4가지와 균등계수 3가지를 선정하였고 평균입경과 균등계수를 각각 달리한 총 12종류의 대표적 준설매립토의 입도분포를 선정, 시료를 제작하였다. 제작된 시료를 이용하여 진동삼축시험을 수행하여 평균입경과 균등계수가 액상화 저항강도에 미치는 영향을 분석하였다. 또한 공진주시험을 수행하여 입도분포가 동적물성치에 미치는 영향도 분석하였다.