• 제목/요약/키워드: Freezing and thawing test

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Soilcrete 의 동결융해 특성 (The Freezing -Thawing Characteristics of Soilcrete)

  • 송창섭;반창현;장웅희
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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    • pp.625-631
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    • 1999
  • In this study, a series of test was conducted to show the characteristics of freezing -thawing process on soilcrete using the soft clay in a redevelopment paddy area, was treated with cement and several additives such as Beestar, CaSO4 , MgO, and polypropylene fiber, From the results of test, it was found that first addtivies -cement and beestar-was effective for compressive strength, and the resistance against freezing -thawing process was improved by secondary additives, in the order their effectiveness, i.e. CaSO4 , Synthetic fiber, MgO and Beestar.

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동결융해작용을 받는 암반사면의 안정성해석에 관한 연구 (Study on Stability Analysis of Rock Slope Under Freezing-Thawing Cycle)

  • 백용
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2000년도 가을 학술발표회 논문집
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    • pp.543-550
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    • 2000
  • Rock slopes along the road or railroad are affected by temperature and therefore experienced iterative freezing-thawing process between winter and early spring. The purpose of this study is to analyze the stability of rock slopes which are influenced by the deterioration due to the freezing-thawing. The analysis is the homogenization method which evaluates the strength property of discontinuous rock mass, and as a strength failure criterion, Drucker-Prager failure criterion is used. The deterioration property of real rock is obtained by a freezing-thawing laboratory test of tuff and this property of deterioration is quantitated and used as a basic data of stability analysis for rock mass. To evaluate the deterioration depth due to the freezing-thawing in situ rock slope, one dimensional heat conductivity equation is used and as the result I can find that the depth of which is affected by a temperature. After the freezing-thawing depth of model slope is determined, we analyze the pattern of rock mass stength value of rock slope model which excesses the limit of self-load.

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축열조 캡슐 고장원인 분석과 수명시험 모드 결정에 관한 연구 (Study on the Analysis of Failure Cause and Determination of Life Test Mode of Capsule)

  • 강보식;이용범;정동수;이충성
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제18권3호
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    • pp.260-270
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    • 2018
  • Purpose: The purpose of this study is to evaluate the life of the capsule, which is a core part of the heat storage cooling system. This paper will develop a life test mode that can reproduce environment conditions through the analysis of capsule shrinkage and expansion characteristics. Methods: In order to determine the life test mode of the capsule, this paper analyzed the case of field failures and analyzed the deformation characteristics according to the pressure fluctuation of the capsule. The method to find out whether the field failure and deformation analysis results are consistent is the testing with the construction of the repetition pressure test equipment and the thermal cycle test to reproduce the freezing and thawing characteristics. Results: In this study, failure mode analysis and analysis of freezing and thawing characteristics regarding to the capsule positions were completed. Based on this test & analysis results, this paper have been able to determine the main parameters for determining the life test mode, the freezing and thawing time. Conclusion: Determining the lifetime mode of the capsule can be used to improve the life and performance of the thermal storage system.

알카리활성 슬래그 콘크리트의 동결융해 저항성 (Resistance to Freezing and Thawing of Alkali-Activated Slag Concrete)

  • 문재성;조아람;심재일;양근혁
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2011년도 추계 학술논문 발표대회
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    • pp.105-106
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    • 2011
  • The present tests examined the resistance to freezing and thawing of alkail-activated (AA) slag concrete having compressive strength between 30~56 MPa. To enhance the compressive strength and resistance to freezing and thawing of AA slag concrete, Na ions were used for an activator. Test results revealed that the resistance to freezing and thawing of AA slag concrete is comparable to that of cement concrete when compressive strength is more than 50 MPa.

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증기양생조건이 시멘트 모르타르의 동결융해저항성에 미치는 영향 (An Experimental Study on the Freezing and Thawing Resistance of Mortar Influenced by Steam Curing Conditions)

  • 장문기;박광수;김관호;윤성수
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 2001년도 학술발표회 발표논문집
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    • pp.185-188
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    • 2001
  • In this study, the characteristics of freezing and thawing resistance, the compressive strength, and the change in height of cement mortar according to a steam and taler curing conditions has been studied. To this end, the major test variables include the period of the early curing, curing temperature and the later curing. The strength test as well as volume variousness have been conducted to explore the characteristics of freezing and thawing resistance on the curing conditions. The experimental results can be efficiently used to improve the characteristics of freezing and thawing resistance for concrete products carrying steam curing.

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동해와 염해를 동시에 받는 콘크리트의 복합열화에 관한 연구 (A Study on the Combined Deterioration of Concrete subjected to Freezing-Thawing and Chloride Attack)

  • 김은겸;최상덕
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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    • pp.225-228
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    • 2005
  • This paper was accomplished for analyzing the reason of the above deterioration happened on the deck of concrete bridge. The bridge was constructed at 660m above the sea level having more freezing and snowing days. Therefore, it is placed on the particular condition sprinkling $CaCl_2$ enough for keeping up with moderate traffic condition. When it is considered to the former condition, the bridge can be assumed to potentialities for combined deterioration with freezing-thawing under sprinkling deicing chemical. Core specimens were gathered from the concrete deck for clearing the reason of the above deterioration exactly, and it is used for various tests for measuring the compressive strength, elastic modulus, content of $Cl^-$, freezing-thawing at the fresh and salt water. As a result of freezing-thawing test, the specimen at the fresh water has over 90$\%$ of durability factor, but another specimen at 1$\%$ of salt water has 0$\%$ of durability factor at 140 cycles of the freezing-thawing. The result means that frost damage is sccelerated at the salt water. Therefore, the deterioration of the concrete deck is estimated to be occured by combined effects of freezing-thawing and chloride ion attack.

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폐광미-소석회 고화체의 동결융해 내구성에 관한 연구 (Durability of the Solidified Mine Tailing-Hydrated Lime Mixture Against Repeated Freezing and Thawing)

  • 민경원;이현철;김태풍
    • 산업기술연구
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    • 제28권B호
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    • pp.65-69
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    • 2008
  • The tailings piled in abandoned mines are well-known potential sources of soil contamination. Hydrated limes were applied as cementing materials to solidify heavy metal contaminated tailings for the purpose of reducing their toxicity and migration rates. The optimum mixing ratio of tailings, hydrated lime, and water was determined through a preliminary test. The mixtures of mine tailings and hydrated lime solidified through pozzolanic reaction were tested for their durability against repeated freezing and thawing processes. After repeated freezing and thawing, the uniaxial compressive strengths of all the solidified mixture specimens decreased in comparison with those before test but still higher than $3.5kgf/cm^2$, the standard recommended for land reclamation solids by EPA(Environmental Protection Agency), which suggested that hydrated lime be a potential material to treat the abandoned mine tailings for the environmental purpose.

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비소성 무기결합재를 사용한 무시멘트 다공성 식생콘크리트의 물리·역학적 특성 및 동결융해저항성 평가 (Physical, Mechanical Properties and Freezing and Thawing Resistance of Non-Cement Porous Vegetation Concrete Using Non-Sintering Inorganic Binder)

  • 김황희;김춘수;전지홍;박찬기
    • 한국농공학회논문집
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    • 제56권5호
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    • pp.37-44
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    • 2014
  • The physical, mechanical and freezing and thawing properties of non cement porous vegetation concrete using non-sintering inorganic binder have been evaluated in this study. Four types of porous vegetation concrete according to the binder type is evaluated. The pH value, void ratio, compressive strength, repeated freezing and thawing properties were tested. The test results indicate that the physical, mechanical and repeated freezing and thawing properties of porous vegetation concrete using the non-sintering inorganic binder is increased or equivalent compared to the porous vegetation concrete using the blast furnace slag + cement and hwang-toh + cement binders. Also, Vegetation monitoring test results indicate the porous vegetation concrete using the non-sintering inorganic binder have increasing effects of vegetation growth.

콘크리트의 동해열화 메커니즘에 관한 실험적 연구 (Experimental Study on the Frost Deterioration Meterioration Mechanism of Concrete)

  • 이승한;이순환;정해구;한형섭
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1996년도 가을 학술발표회 논문집
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    • pp.169-174
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    • 1996
  • It have been announced that concrete subjected to freezing and thawing cause deterioration by expanded inside water and contracted at thawing. However, this study descrebe the deterioration mechanism of concrete by freezing and thawing test. Embeded strain gauges were used to measure the inside restrict strain due to the temperature differenct inside and outside the concrete test specimens. Test results showed that using the air entrained admixture and expanded poly-styrene was developed durability of concrete by decreasing inside retrict strain ratio.

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증기양생방법에 따른 모르타르의 동결융해 특성에 관한 실험적 연구 (An Experimental Study on Freezing and Thawing Characteristics of Mortar Influenced by Steam Curing Methods)

  • 장문기;박광수;김관호;이준구
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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    • pp.967-972
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    • 2001
  • In this study, the characteristics of freezing and thawing resistance, the compressive strength, and the change in height of cement mortar according to steam curing methods has been studied. To this end, the major test variables include the period of the early curing, curing temperature and the later curing. The strength test as well as volume variousness have been conducted to explore the characteristics of thawing and thawing resistance on the curing methods. The experimental results in the present study can be efficiently used to improve the characteristics of freezing and thawing resistance for concrete products carrying steam curing.

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