• 제목/요약/키워드: Freezing resistance

검색결과 371건 처리시간 0.025초

자연마섬유보강 비소성 무기결합재 다공성 콘크리트의 공극률, 압축강도 및 동결융해저항성 평가 (Void Ratio, Compressive Strength and Freezing and Thawing Resistance of Natural Jute Fiber Reinforced Non-Sintering Inorganic Binder Porous Concrete)

  • 김황희;김춘수;전지홍;박찬기
    • 한국농공학회논문집
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    • 제57권2호
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    • pp.67-73
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    • 2015
  • This study evaluated the effects of fibers on the void ratio, compressive strength and repeated freezing and thawing resistance of porous vegetation concrete with binder type (non-sintering inorganic binder and blast furnace slag cement) and natural jute fiber volume fraction (0.0 %, 0.1 % and 0.2 %). The natural jute fiber volume fraction affected the void ratio, compressive strength and repeated freezing and thawing resistance. Added of natural jute fiber resulted in improved properties of the void ratio, compressive strength and freezing and thawing resistance. Also, the both compressive strength and freezing and thawing resistance increased with natural jute fiber volume fraction up to 0.1 % and then decreased with fiber volume fraction at 0.2 %.

제강슬래그를 굵은 골재로 이용한 콘크리트의 동결융해 저항성 (Freezing-Thawing Resistance of Concrete Using Steel Slag as Coarse Aggregate)

  • 이효성;한상호
    • 공학기술논문지
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    • 제11권4호
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    • pp.295-301
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    • 2018
  • In this study, freezing-thawing resistance of concrete using steel slag as coarse aggregate(steel slag concrete) from Gwangyang Iron Co. was estimated to offer basic data for utilization of much more steel slag. Freezing-thawing test of concrete using crushed stone as coarse aggregate(crushed stone concrete) whose compressive strength and air contents are as close as possible to those of the steel slag concrete was performed. Because they are main two factors that affect of freezing-thawing resistance. The test was carried out up to 400 cycles according to KS F 2456. The compressive strength and weight of two concretes were measured and compared. As a result, the freezing-thawing resistance of steel slag concrete curing in water was almost the same with that of crushed stone concrete. But the resistance of steel slag concrete curing in air dry condition was weaker than that of crushed stone concrete. Also, the steel slag concrete which has more than 60% of W/C ratio showed much more surface degradation when compared to crushed stone concrete.

동결융해 저항성 시험방법에 따른 경량골재 콘크리트의 특성 (Characteristics of Lightweight Aggregate Concrete according to Freezing and Thawing Resistance Test Methods)

  • 김세환;김상헌;이수형;전현규;서치호
    • 한국건축시공학회지
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    • 제13권3호
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    • pp.202-208
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    • 2013
  • The method used to test lightweight aggregate concrete for its resistance to freezing and thawing is different in each country. In Korea, the method of KS F 2456 on normal concrete is adopted for lightweight aggregate concrete, while the testing method of ASTM C 330 lightweight aggregates for structural concrete is used in the majority of overseas countries. In this study, we identified differences between KS F 2456 and ASTM C 330 in terms of the testing method for freezing and thawing resistance, and we studied the influence of this on the freezing and thawing resistance of lightweight aggregate concrete. The results of this study were as follows: Blocked lightweight aggregates had a slight collapse of shape and lost weight by repeated freezing and thawing, but unblocked lightweight aggregates were badly collapsed. And while the freezing and thawing resistance tests of normal concrete showed similar results despite the difference in the KS and ASTM testing method, the results for lightweight aggregate concrete were very different. So the KS test method shows evaluation results that are much lower than the ASTM test method.

Evaluation on Surface Scaling and Frost Resistance for concrete Deteriorated due to Cyclic Freezing and Thawing with Inherent Chloride

  • Kim, Gyu Yong;Cho, Bong Suk;Lee, Seung Hoon;Kim, Moo Han
    • Corrosion Science and Technology
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    • 제6권4호
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    • pp.177-185
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    • 2007
  • The purpose of this study is to evaluate freezing-thawing and surface scaling resistance in order to examine the frost durability of concrete in a chloride-inherent environment. The mixing design for this study is as follows: 3 water binder ratios of 0.37, 0.42, and 0.47; 2-ingredient type concrete (50% OPC concrete and 50% ground granulated blast-furnace slag), and 3-ingredient type concrete (50% OPC concrete, 15% fly ash, and 35% ground granulated blast-furnace slag). As found in this study, the decrease of durability was much more noticeable in combined deterioration through both salt damage and frost damage than in a single deterioration through either ofthese; when using blast-furnace slag in freezing-thawing seawater, the frost durability and surface deterioration resistance was evaluated as higher than when using OPC concrete. BF 50% concrete, especially, rather than BFS35%+FA15%, had a notable effect on resistance to chloride penetration and freezing/expansion. It has been confirmed that surface deterioration can be evaluated through a quantitative analysis of scaling, calculated from concrete's underwater weight and surface-dry weight as affected by the freezing-thawing of seawater.

Genetic Analysis of Apoplastic Proteins in Barley Crosses

  • Chun, Jong-Un;Choi, Kap-Seong;Griffith, Marilyn
    • Plant Resources
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    • 제7권2호
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    • pp.147-154
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    • 2004
  • Antifreeze proteins (AFPs) accumulate in the leaves of barley during cold acclimation, where they may inhibit ice recrystallization and produce freezing resistance of the plant. Four parental diallel crosses of the barley varieties were used to determine the heritability of AFPs and the relationship between the accumulation level of AFPs and freezing resistance. The concentration of apoplastic proteins in the cold-acclimated leaves was increased in the mean by four-fold over as compared with that of nonacclimated. The diallel cross analyses revealed that the gene of Sacheon 6 was dominant and those of Reno and Dongbori 1 were recessive. The AFPs had high narrow-sense heritabilities. The general combining ability effects of Reno and Dongbori 1 were much higher than the other parents. The bands of 32-kD for GLP, 35-& 28-kD for CLP and 25-, 22- & 16-kD for TLP were observed in the apoplastic extracts from cold-acclimated plants, but there were no clear differences between the parents and Fl hybrids. The concentrations of AFPs were significantly correlated with the degree of freezing resistance, indicating that the concentration of AFPs in the plant is the very important factor for freezing resistance.

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한랭지에 있어서 고류동콘크리트의 동해에 관한 연구 (Study on the Frost Damage of Self-Compacting Concrete in Cold Weather Regions)

  • 고경택;이장화;한상묵;장일영
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
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    • pp.763-766
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    • 1999
  • The objective of this study was to investigate the influence of low temperature curing on resistance of freezing and thawing of self-compacting concrete placed in cold weather regions. The experimental study results indicated that the self-compacting concrete incorporating ground granulated blast-furnace slag showed good resistance to freezing and thawing, and the self-compacting concrete cellulose viscous agent had relatively poor resistance to freezing and thawing.

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동결융해 및 중성화를 받은 콘크리트의 철근 부식 특성 (Corrosion of Steel in Concrete Deteriorated by Freezing/Thawing and Carbonation)

  • 정해문;김종우;이대근;최광일
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1997년도 가을 학술발표회 논문집
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    • pp.293-298
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    • 1997
  • Corrosion of steel reinforcing in concrete deteriorated by freezing/thawing and carbonation was characterized. Concrete specimens were prepared using various kinds of cements such as ordinary portland cement (type I), low heat portland cement (type IV, belite rich cement), sulphate resistance portland cement (type V), blast furnace slag portland cement and ternary blended cement. Of various cements, type V and type IV with lower $C_3A$ content revealed better steel corrosion resistance after freezing/thawing and carbonation. $C_3A$ content in cement might affect freezing/thawing resistance in sea water.

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제설제 사용으로 인한 노면 미끄럼저항 특성 연구 (A Study of Skid Resistance Characteristics by Deicing Chemicals)

  • 이승우;우창완
    • 대한토목학회논문집
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    • 제26권5D호
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    • pp.813-819
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    • 2006
  • 미끄럼 저항은 타이어와 도로노면의 마찰저항을 나타내는 지수로 차량의 주행 안전성에 지대한 영향을 미친다. 타이어의 상태, 노면의 마모도, 주행속도, 노면의 건조, 습윤, 결빙 등에 따라 미끄럼저항의 크기는 달라진다. 특히 겨울철 도로노면의 경우 강설 후 기온강하에 도로포장표면이 결빙이 발생할 경우 미끄럼저항이 급격히 저하되며, 미끄럼저항을 회복하고자 제설 작업을 수행하게 된다. 제설작업 후에는 습윤상태로 노면조건이 바뀌게 되는데, 제설제가 노면에 잔류하게 되면 일반적인 습윤상태에서의 미끄럼저항을 확보치 못할 수 있다. 본 연구에서는 국내 포장도로의 대다수를 차지하는 밀입도 아스팔트와 타이닝 콘크리트 포장노면에 대하여 실험실 조건에서 노면 결빙시, 제설중 제설후 잔류물이 노면에 있을 경우의 조건에서의 미끄럼저항을 정량적으로 평가하였다. 연구 결과 노면 결빙시 미끄럼저항 회복시간은 수용액 살포방법이 고체염 살포방법 보다 빠르며 제설제 중에는 소금이 가장 빠르게 나타났다. 노면에 잔류한 제설제는 콘크리트 시편이 아스팔트 시편보다 미끄럼저항 값이 높게 나타났으며 습윤 노면 상태와 비교시 미끄럼저항 확보율은 54~80% 이다.

폴리머-시멘트 모르타르의 미세구조 동결융합 저항성의 관계 (The Relationship between Microstructure and Freezing Thawing Resistance of Polymer-Cement Mortars)

  • 황의환;황택성
    • 한국세라믹학회지
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    • 제31권9호
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    • pp.949-956
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    • 1994
  • In order to investigate the relationship between pore size distribution and freezing-thawing resistance of mortars, polymer-cement mortars were prepared by using styrene-butadiene rubber latex, ethylene-vinyl acetate emulsion and polyacrylic ester emulsion with various polymer-cement ratios at constant flow. From the results of the test, polymer-cement mortars had a good pore size distribution for freezing-thawing resistance compared with unmodified mortars because of having a small pore volume in the pore radius range of 103~104 $\AA$ affecting on the frost damage. And the freezing-thawing resistance of polymer-cement mortars was improved with increasing polymer-cement ratio.

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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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