• Title/Summary/Keyword: durability deterioration

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The Standardized Methods for Improvement of Maintenance Deterioration caused by Fire damage (국제 표준화를 위한 화재이후의 유지관리 시스템 개발)

  • Kwon, Young-Jin;Koo, In-Hyuk;Kim, Dong-Eun;Seo, Dong-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2013.11a
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    • pp.230-231
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    • 2013
  • A fire outbreak in a reinforcement concrete structure looses the organism by different contraction and expansion of hardened cement pastes and aggregate, and causes cracks by thermal stress, leading to the deterioration of the durability. So, concrete reinforcement structure is damaged partial or whole structure system. Therefore accurate diagnosis of deterioration is needed based on mechanism of fire deterioration in general concrete structures. Fundamental information and data on the properties of concrete exposed to high temperature are necessary for accurate diagnosis of deterioration. In this study, consider case of investigation methods and repair work in fire damaged structure concrete.

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The Standardized Methods for Improvement of Maintenance and Performance Construction of Deterioration caused by Fire damage (화재피해 콘크리트의 유지관리 및 시공성능 향상을 위한 표준화방안)

  • Seo, Dong-Goo;Kim, Dong-Eun;Kim, Bong-Chan;Kwon, Young-Jin
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2013.05a
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    • pp.16-18
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    • 2013
  • A fire outbreak in a reinforcement concrete structure looses the organism by different contraction and expansion of hardened cement pastes and aggregate, and causes cracks by thermal stress, leading to the deterioration of the durability. So, concrete reinforcement structure is damaged partial or whole structure system. Therefore accurate diagnosis of deterioration is needed based on mechanism of fire deterioration in general concrete structures. Fundamental information and data on the properties of concrete exposed to high temperature are necessary for accurate diagnosis of deterioration. In this study, consider case of investigation methods and repair work in fire damaged structure concrete.

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Coating Durability of Metal Bipolar plate for Low Temperature PEMFC (저온 PEMFC용 금속분리판 코팅의 내구 특성 연구)

  • Kang, Sungjin;Jeon, Yootaek
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.11a
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    • pp.82.2-82.2
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    • 2010
  • The development of bipolar plate having high efficiency and chemical properties has a major impact on fuel cell applications commercialization. Even though graphite bipolar plate has high electric conductivity and chemical resistance, it has demerits about mass production and brittle property for commercialization. Hence, metallic bipolar plate can be substitute for fuel cell bipolar plate. Although its inadequate corrosion behavior under PEMFC environment lead to a deterioration of membrane by dissolved metal ions, metallic bipolar plate for PEMFC is more suitable for automotive and residential power generation system because of its high mechanical strength, low gas permeability and applicability to mass production. Therefore, several types of coating has been applied to prevent corrosion and oxide film growth and to achieve more high durability. This work presents durability of coated metal bipolar plate for low temperature PEMFC which made for fuel cell vehicle. This results showed surface treatment increase long-term durability, even electric conductivity and corrosion resistance.

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Durability Etimation with Deterioration of Concrete in Nuclear Structure (원전구조물 콘크리트의 열화에 따른 내구성 평가)

  • Won, Min-Sik;Choi, Yoon-Suk;Shin, Jung-Ho;Yang, Eun-Ik;Kim, Ho-Jin;Kim, Do-Kyum
    • Proceedings of the Korea Concrete Institute Conference
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    • 2010.05a
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    • pp.223-224
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    • 2010
  • As the demand on nuclear power is increasing, it is required to investigate for concrete durability in nuclear structure. However, the inspected datas for durability are insufficient in nuclear structure. The test specimens are prepared according to the mix design that has been used in the domestic nuclear structure. And, the characteristics of durability are investigated for the specimens. It will be needed to estimate the long-term durability.

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Comparison of High-Durability Materials for Prevention of Corrosion in Marine Concrete Structures (해양콘크리트구조물의 부식 방지를 위한 고내구성 재료의 성능비교)

  • Lee, Dong-Gun;Kim, Myung-Yu;Yang, Eun-Ik;Yi, Seong-Tae;Han, Sang-Hoon
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.11a
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    • pp.581-584
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    • 2006
  • The durability of reinforced concrete structures is severely degraded by mainly corrosion due to seawater attack and chloride ion diffusion in concrete. The deterioration of durability causes high repair cost for maintenance of marine concrete structure. In this paper, high-durability materials for prevention of rebar corrosion are investigated to promote the durability in marine concrete structures. For these, the effect of the mineral materials addition(SF, FA and BFS), the modified steel(stainless and coating steel). and corrosion inhibitors are compared.

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An Experimental Study on the Effect of Accelerator and Chemical Admixture Type for the Durability of Shotcrete (급결제 및 혼화제 종류가 숏크리트 내구성에 미치는 영향에 관한 연구)

  • 백신원;권소진;이영수;김의성;신용석
    • Journal of the Korean Society of Safety
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    • v.18 no.3
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    • pp.109-113
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    • 2003
  • Concrete and shotcrete should withstand the conditions for which they have been designed, without deterioration, over a period of years. But connote and shotcrete are being deteriorated according to aging by internal and external causes. Recently, many studies on the durability of concrete have been conducted But the durability of shotcrete is rarely studied. So, in this study, chloride ion penetration test freeze and thaw test neutralization test were conducted to examine the durability characteristics of shotcrete with several accelerator and chemical admixture types. These results indicate that shotcrete with allah free accelerator and with superplasticizer are durable. Therefore, the present study provides a fm base to make high performance shotcrete.

Development and Application of Low Permeable Concrete for Underground Structures (지하구조물을 위한 수밀콘크리트의 개발 및 실용화)

  • Paik, S.H.;Park, S.S.;Park, J.Y.;Paik, W.J.;Um, T.S.;Choi, L.
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.10a
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    • pp.259-262
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    • 1999
  • In underground reinforced concrete structures, such as drainage structure, water and chloride ion penetrated into concrete through the cracks of concrete and its permeable property, cause the corrosion of reinforcing steel bar, which accelerates the expansive cracks and deterioration of concrete. It is necessary to control those deterioration of underground structure by improving its permeability and durability through the reasonable solutions in design, construction and materials. In the present study, fly ash concrete, which has good material properties in long-term period, was compared and studied with plain concrete using ordinary portland cement in terms of fundamental mechanical properties, permeability, drying shrinkage and durability. Also, the mix design and field test of low permeable concrete using fly ash were performed. From this study, fly ash concrete can control the penetration of water and chloride ion effectively by forming dense micro-structure of concrete. Therefore, fly ash concrete may increase the long-term function, performance and serviceability of underground structures.

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Strength and durability studies on high strength concrete using ceramic waste powder

  • Karthikeyan, B.;Dhinakaran, G.
    • Structural Engineering and Mechanics
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    • v.61 no.2
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    • pp.171-181
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    • 2017
  • This paper summarizes the study on effect of ceramic waste powder as partial substitute to cement in binary blend and along with silica fume in ternary blend high strength concrete in normal and aggressive environments. Strength parameters such as compression & tension and durability indices such as corrosion measurement, deterioration, water absorption and porosity were studied. Ceramic waste powder was used in three different percentages namely 5, 10 and 15 with constant percentage of silica fume (1%) as substitutes to cement in ternary blend high strength concrete was investigated. After a detailed investigation, it was understood that concrete with 15% ceramic waste powder registered maximum performance. Increase of ceramic waste powder offered better resistance to deterioration of concrete.

Breakage Characteristics of Ballast (도상자갈의 마모/파쇄 특성)

  • 정근영;김현기;이종득
    • Journal of the Korean Society for Railway
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    • v.2 no.3
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    • pp.61-69
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    • 1999
  • The durability of ballast plays an important role in track behaviour. To estimate the deterioration characteristics of ballast, several tests have been carried out by several scholars. The deterioration characteristics is very important factor in the behaviour of track and its life. In this paper, abrasion/breakage characteristics of ballast is studied to see the effect of physical ballast characteristics on ballast life. To reveal breakage characteristics of ballast, the ballast box test and the MTT field test were carried out. The breakage characteristics studied in this paper is applied to the ballast life prediction in various conditions, such as LA abrasion, annual tonnage, tamping number per year, etc

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An Experimental Study on the Chloride Diffusion of Concrete by Experimental in Room of Individual and Combined Deterioration (단독 및 복합열화의 실내촉진실험에 의한 콘크리트의 염화물 확산에 관한 실험적 연구)

  • Kim, Young-Sun;Koo, Kyung-Mo;Kim, Young-Duck;Cho, Bong-Suk;Kim, Gyu-Yong;Kim, Moo-Han
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.05a
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    • pp.574-577
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    • 2006
  • Recently, the deterioration due to salt damage and carbonation as the main factors of deteriaoration of the domestic reinforced concrete structures has been increased. Also the national and social concern about the durability recovery of the deteriorated reinforced concrete structures is geratly being raised. Therefore, it is the final purposes of this study to develop the performance evaluation technique for durability of reinforced concrete structures deteriorated due to salt damage and carbonation with the proposal of the service life prediction method for the investigation and diagnosis of reinforced concrete structures, and accelerated test in Lab.

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