• 제목/요약/키워드: Freeze/Thaw

검색결과 422건 처리시간 0.031초

동결-융해작용에 따른 암석풍화의 특성 (The Effect of a Freeze-Thaw Cycle on Rock Weathering: Laboratory Experiments)

  • 양재혁
    • 한국지형학회지
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    • 제18권3호
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    • pp.21-36
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    • 2011
  • 암석의 풍화작용은 지형발달에 있어 물질의 준비과정으로서 역할을 한다. 이 중 동결-융해작용은 한대지역이나 주빙하 지역뿐만 아니라 심지어 온대지역에서도 암석을 파괴시키는데 효과적인 프로세스로 여겨져 왔다. 화강암(생암, 반풍화층), 편마암, 석회암, 돌로마이트의 슬랩시편 각각 10개를 -25℃~+30℃의 조건으로 동결-융해를 180회 반복하고 이들의 풍화양상과 물리적 특성변화를 검토한 결과, 파쇄는 대기와 토양조건보다는 침수조건에서 좀 더 활발히 진전되었으며 공극률이 높은 석회암과 돌로마이트가 가장 심하게 파쇄되었다. 편마암은 표면에 crack, joint, fissure들이 발달해 있고 암석강도(SHV)가 가장 낮았음에도, 어떠한 물리적 변화나 풍화산물들이 생성되지 않아 풍화에 저항력이 매우 높은 암석으로 나타나고 있다.

Performance Evaluation of Inter-Locking Block Using Fly Ash

  • Shin, Byung-Chuel
    • 한국환경과학회지
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    • 제13권2호
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    • pp.143-148
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    • 2004
  • In this paper, the properties of inter - locking block using fly ash are discussed in order to provide economical advantages and improve quality, and protect environment and recycle resources. Fly ash is the by-product of coal in thermal power plant. The experimental parameters are fly ash content, the amount of AE water - reducing agent and mixing proportion of cement mortar. According to the experimental results, the improvement of quality in the side of strength, absorption ratio and freeze - thaw resistance for manufacturing inter -locking block and the curtailment of cost can be achieved in case of 15% of fly ash and 0.3% of AE water- reducing agent are mixed into mortar mixture of 1 :6(C:S).

경계블록의 내구성 향상을 위한 연구 (A Study on Increasing Durability of Concrete Curbing Block)

  • 엄태선;임채용;유재상;이종열;이근호;김응수
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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    • pp.765-770
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    • 2001
  • Concrete curbing blocks have been widely used in construction of roadways because they are easy too manufacture and cheap. But recently stone curbs are taking away the role from concrete curbs, because the durability of concrete curbs is inferior to stone curbs. Especially freeze-thaw effect on concrete is the most important cause that damages concrete curbs. The aim of this study is to increase the durability of concrete curbs. The concrete curbs that have been manufactured are extremely damaged below 60 cycles of freeze-thaw, but the ones that was manufactured with admixtures that entrains air are maintaining over 87% of relative dynamic modulus.

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염화물 함유에 의한 콘크리트의 내동해성 및 표면열화에 관한 연구 (A Study on the Scaling Deterioration and Resistance to Freezing of Concrete by Containing Chlorides)

  • 박주헌;김규용;김한준;권영호
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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    • pp.372-375
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    • 2004
  • Scaling deterioration and resistance to freezing of port concrete structures due to the combined effects of chemical actions by containning chlorides and the freeze-thaw action is also a problem which has not yet been fundamentally solved. Furthermore, deterioration of concrete surface was considered as accelerate factor of concrete durability tended to decrease. Therefore, we considered the scaling measuring method and decreasing influence of durability of concrete according to kind of binders, such as OPC, Slag, Slag+Fa, due to freeze and thaw of concrete by containing chlorides. As a results of this study, it was effective method of scaling deterioration and resistance freewing of concrete, and confirmed the salt deterioration resistance effect to use slag binder against to containing chlorides.

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섬유 혼합토의 공학적 특성 (Engineering Properties of Fiber Mixed Soil)

  • 장병욱;박영곤
    • 한국농공학회지
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    • 제44권1호
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    • pp.116-124
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    • 2002
  • Natural resources fur the construction materials such as good soil, sand, and coarse aggregates have been encountered to be short due to excessive use by human. Even though some soil has been found to be unsuitable for construction materials, soil with reinforcement can naturally be an answer to these alternatives. According to recently published papers on fiber mixed soil, fiber mixed with soil can improve shear strength, compressive strength and post-peak load strength retention. In this study, a series of tests were performed to clarify the characteristics of fiber mixed soil and to give basic data for design and construction and their engineering properties, that is, unconfined compressive strength, splitting tensile strength, shear strength, crack by drying, freeze-thaw, creep and Poisson\`s ratio, were investigated and analyzed. It has been shown that fiber mixed soil is one of good alternatives fur the civil and building construction materials.

CKD 혼합에 따른 Recycled Material의 회복탄성계수와 일축압축강도 특성 (Characteristic of Resilient Modulus and Unconfined Compressive Strength for Recycled Materials blend with Cement Kiln Dust)

  • 손영환
    • 한국농공학회논문집
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    • 제52권2호
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    • pp.19-25
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    • 2010
  • This study was conducted to determine the resilient modulus (Mr) and the unconfined compressive strength (UCS) of two recycled roadway materials such as recycled pavement material (RPM) and road surface gravel (RSG) with or without cement kiln dust (CKD). The recycled materials were blended with two CKD contents (5, 10 %) and 28 day curing time. Mr and UCS tests were also conducted after 10cycles of freezing and thawing to asses the impact of freeze-thaw cycling. Mr was determined conducting by the laboratory test method described by NCHRP 1-28A. Stabilized RPM and RSG had a modulus and a strength higher than unstabilized RPM and RSG. Mr and UCS of RPM and RSG mixed with CKD increased with increasing CKD content. The results indicated that the addition of CKD could be improved the strength and the stiffness of RPM and RSG. Therefore, RPM, RSG and CKD could be used as an effective materials in the reconstruction of roads.

라텍스 혼입에 따른 LMC의 동결융해 저항특성평가 (Freezing and Thawing Resistance of Latex Modified Concrete with Latex Content)

  • 이주형;정원경;김동호;이봉학;원치문;이정호
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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    • pp.497-502
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    • 2000
  • This study was performed to change the latex content for properties of freezing-thawing resistance. When styrene-butadiene latex is added to portland cement, aggregate and water, a concrete with the color, consistency and workability of ordinary conventional concrete results, but with 20% to 35% less water. When cured, the concrete consists of hydrated cement and aggregate interconnected by a film of latex particles. In general, increasing the amount of latex will produce concrete with increased tensile and flexural strength and lower modulus of elasticity. Air entrainment has been used in conventional concrete for the past 50 years to impart freeze-thaw resistance. Latex modified concrete does not need additional air entrainment for freeze-thaw resistance provided adequate cure occurs.

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급결제를 이용한 분말수지 혼입 폴리머 시멘트 모르타르의 부착강도 및 내구성 평가 (Evaluation of Durability and Bond Strength of Polymer Powder-Modified Mortars With Accelerators)

  • 이철웅;문경주;송훈;김병철;최낙운;소양섭
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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    • pp.559-562
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    • 2005
  • The purpose of this study is to evaluate the durability and bond strength of polymer powder-modified mortars with special accelerator components. The mortars were prepared with various polymer-binder ratios and applied to the concrete substrate as a repair material. Bond strength, flexural and compressive strengths, freeze-thaw resistance and carbonation resistance were measured for the test. As a result, bond strength of the mortars was increased with an increase in the polymer-cement ratio, and freeze-thaw resistance and carbonation resistance were significantly improved with increasing polymer-cement ratio also.

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물시멘트비에 따른 플라이애시 콘크리트의 동결융해 저항성에 관한 연구 (Effects of water-cement ratio on the freeze thaw resistance of fly ash concrete)

  • 김도겸;이장화;이호재;김재환
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2010년도 춘계 학술대회 제22권1호
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    • pp.211-212
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    • 2010
  • 본 연구는 플라이애시를 혼입한 콘크리트의 물시멘트비에 따른 동결융해 저항성을 알아보기 위해 페이스트, 모르타르, 콘크리트 시편을 제작, 실험을 진행하였다. 페이스트와 모르타르는 길이, 무게변화를 측정하였으며 콘크리트는 질량변화와 동탄성계수를 측정함으로써 동결융해 저항성을 측정하였다.

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동결융해 및 부착재료 변화에 따른 FRP-Concrete 경계면의 최대 부착강도 및 유효부착길이 평가 (Inverstigation of Maximum Strength and Effective Bonding Length at the Interface between Concrete and FRP Materials under Freeze-thaw Cycles and Applied Different Bonding Materials)

  • 김성훈;정우영;최현규
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2010년도 춘계 학술대회 제22권1호
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    • pp.435-436
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    • 2010
  • 본 연구는 동결융해 및 부착재료의 변화에 따른 FRP-콘크리트 부착 경계면의 부착강도 및 유효부착길이의 변화를 조사하였으며, 본 연구 결과를 이용, 개선된 유효부착길이 관계식을 제안하였다.

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