• Title/Summary/Keyword: Salt attack

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Distribution properties of seasonal airborne sea salt in the seashore (해안가의 계절별 비래염분량의 분포 특성)

  • Lee, Jong-Suk;Choi, Won-Sung;Moon, Han-Young
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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    • pp.237-240
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    • 2004
  • When the concrete structures are in contact with seawater, concentration of chloride for estimating chloride diffusion coefficient can be defined as the chloride concentration of sea water. However, in case the concrete structures, constructed in the seashore, aren't directly in contact with seawater, it is difficult to establish the interface concentration of chloride. In addition, marine concrete structures are greatly affected by salt attack such as rebar corrosion, among the cause of salt attack, airborne sea salt is primary factor. Therefore, in this study, salt attack environment by airborne sea salt was investigated in terms of a seasonal distribution at 33 spots, 6 areas in the East, West, South coast for 1 year. Results indicated that in the South coast, the amount of the airborne sea salt is comparatively higher in summer. in the West coast. higher in winter. On the other hand, in the East coast, the amount of the airborne sea salt is rarely affected by a season.

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Development of Multidiretion Incoming Salt Collector (다방향 비래염분 포집기 개발 및 포집 정확도 검증)

  • Park, Dong-Cheon;Ahn, Jae-Cheol;Kim, Woo-Jae;Oh, Sang-Gyun;Kim, Hyo-Youl;Kang, Byung-Hi
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2011.05a
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    • pp.13-14
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    • 2011
  • Reinforced concrete structures are damaged by concrete carbonation, salt attack, and sulfate attack. The evaluation of the amount of chloride ion from the sea is very important to assess the life expectancy of Reinforced Concrete structures. The incoming salt collector which is developed in Japan has been used until the present, Unfortunately, the incoming salt collector has had a bad reputation which is caused by backward wind. The wind from backward causes the reduction of the amount of collected salt in collector's gauze. The collector was developed for excluding the effect of backward wind. The performance of it was verified from analytic and experimental methods.

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A study on the distribution of airborne sea salt to the distance from seashore (해안으로부터 거리별 비래염분량의 분포에 대한 고찰)

  • Lee, Jong-Suk;Choi, Won-Sung;Moon, Han-Young
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.05a
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    • pp.842-845
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    • 2004
  • When the concrete structures are in contact with seawater, concentration of chloride for estimating chloride diffusion coefficient can be defined as the chloride concentration of sea water. However, in case the concrete structures, constructed in the seashore, aren't directly in contact with seawater, it is difficult to establish the interface concentration of chloride. In addition, marine concrete structures are greatly affected by salt attack such as rebar corrosion, among the cause of salt attack, airborne sea salt is primary factor. Therefore, in this study, salt attack environment by airborne sea salt was investigated in terms of the distance from seashore at 33 spots, 6 areas in East, West, South coast for 1 year. Results indicated that airborne sea salt is decreased by $y=a{\cdot}x^{-b}$ equation to the distance from seashore.

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Durability Evaluation of concrete using fly ash (플라이애시 혼입 콘크리트의 내구성 평가)

  • 조명석;송영철;류금성;고경택;김성욱;이장화
    • Proceedings of the Korea Concrete Institute Conference
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    • 2002.05a
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    • pp.755-760
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    • 2002
  • The concrete structures in marine environment has been used type V cement(sulfate-resisting Portland cement), but according to the study results reported recently, the question has been raised for effect of the resistance to salt attack of the concrete using type V cement. It is increased the demands on the use of mineral admixtures such as fly ash, ground granulated blast-furnace slag instead of type V cement in order to improve the durability of concrete structures. Therefore, this study focused on the durability evaluation of concrete containing fly ash under marine environment, and the tests such as salt attack, carbonation, sulfate attack, and freezing-thawing were performed. Test results showed t]hat the resistance to salt attack, sulfate attack and freezing-thawing was improved, and the carbonation was in some disadvantage compared with normal concrete. Nevertheless, the durability of fly ash concrete would be maintained during the service life of structures.

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Quantization of Transmitted Incoming Salt According to Wind Occurrence Frequency and Wind speed (바람의 발생빈도와 속도에 따른 전송 비래염분 정량화)

  • Cho, Gyu-Hwan;Lee, Hae-Seung;Kim, Woo-Jae;Ahn, Jae-Cheol;Park, Dong-Cheon
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2012.11a
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    • pp.267-268
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    • 2012
  • To evaluate the incoming salt quantitatively which is the reason of salt attack is a very important aspect to calculate the durability life of the structure. Incoming salt is influenced by various weather changes during the transmission and consequently, the changes of incoming salt quantity occur. Therefore, the study to analyze incoming salt quantity was executed which are changed by the weather environments (occurrence frequency of wind direction / wind speed); study results showed that influences to the changes of incoming salt quantity are bigger than those of wind speed, compared with the frequencies.

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The Experimental Study on the Durability of Concrete under Freezing & Thawing Action and Salt attack (염해와 동해를 받는 콘크리트의 내구성 평가실험)

  • Lee, Joan-Gu;Park, Kwang-Su;Cho, Young-Kwon;Kim, Meyong-Won;Kim, Kwan-Ho
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.05b
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    • pp.213-216
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    • 2005
  • Salt attack and freezing & thawing test, one of the combined deterioration tests was performed to explore the mechanism of concrete structure deterioration under marine environment. Simple submerging test was proceeded to draw out its diffusion factor with salt water at the same time. Some of the mechanisms were driven with using three types of cements and four kinds of salt water concentrations. $\circ$ TBC was more durable than OPC or SRC for freezing and thawing action $\circ$ The higher chloride concentration of salt water was, the faster relative dynamic elastic modulus decreased and the higher the loss of weight was. $\circ$ The diffusion factor of TBC was smaller than those of TBC or SRC at simple submergence of concrete specimens into salt water.

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Chloride Ion Diffusion for Ready Mixed Concrete (설계기준 압축강도별 레미콘의 염소이온 확산 특성평가)

  • Park, Dong-Cheon;Kim, Yong-Ro
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2018.11a
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    • pp.149-150
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    • 2018
  • The RC buildings which are constructed on the seaside are followed by KBC(2016) to achieve the minimization of durability damage. To control the corrosion of the reinforced steel bar by salt attack, W/C should be under 0.4 and specified concrete strength is more than 35MPa in the concrete/building construction standard specification. Ready mixed concretes which have usually include the admixtures in Busan were tested to certify the salt attack durability. In the same specified concrete strength, remarkable salt attack durability was evaluated in comparison to OPC.

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An Experimental Study on the Salt Resistance Properties with Concrete Materials under Marine Exposure Environment (I) (해양환경에 폭로한 콘크리트의 내염특성에 대한 실험적 연구 (I))

  • 신도철;김영웅;김용철;김동철
    • Proceedings of the Korea Concrete Institute Conference
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    • 2002.10a
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    • pp.51-56
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    • 2002
  • Protection against salt attack in seawater is obtained by using a dense, quality concrete with a low water-cement ratio, and a components appropriate for producing concrete having the needed salt resistance. The objective of this study is to evaluate the feature of corrosion with using the various concrete materials under marine exposure environment. According to the test results, slag powder and anti -corrosion inhibitor showed high chloride resistance effect. Also concre crack have an influence on corrosion of steel in spite of mixed design for salt resistance concrete. The requirement for low permeability is essential not only to delay the effect of salt attack, but also to afford adquate protection to reinforcement with admixtures.

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The Influence of Carbonation on Physical and Chemical Property in Mortar (모르터의 물리.화학적 특성에 미치는 중성화의 영향)

  • 문소현;소승영;소양섭
    • Proceedings of the Korea Concrete Institute Conference
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    • 1995.10a
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    • pp.30-34
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    • 1995
  • There are carbonatiion, salt attack, freezing & thawing and alkali-aggregate reactions as the cautions of durability lowering of concret structure. Generally, these cautions complicatedly lower the durability of structure and among these cautions the most serious problem is salt attack and carbonation. This study is intending to get the carbonation phenominon, that among cement calcium hydroxides change into calcium carbonate by responding to carbon mitrogen in the air.

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An Experimental Study on the Mixing Design of the Concrete Using Crushed Sand (부순모래 콘크리트의 배합설계에 관한 실험적 연구)

  • 이진규;반호영;윤기원;최응규;한천구
    • Proceedings of the Korea Concrete Institute Conference
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    • 1995.10a
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    • pp.35-40
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    • 1995
  • There are carbonatiion, salt attack, freezing & thawing and alkali-aggregate reactions as the cautions of durability lowering of concret structure. Generally, these cautions complicatedly lower the durability of structure and among these cautions the most serious problem is salt attack and carbonation. This study is intending to get the carbonation phenominon, that among cement calcium hydroxides change into calcium carbonate by responding to carbon mitrogen in the air.

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