• Title/Summary/Keyword: physical deterioration

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A study on the Dynamic Behaviors of Track due to Deterioration characteristics of Ballast (자갈도상의 노후화에 따른 궤도구조의 동적거동에 관한 연구)

  • Park Yong-Gul;Choi Jung-Youl;Kang Duck Man
    • Proceedings of the KSR Conference
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    • 2005.05a
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    • pp.591-596
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    • 2005
  • The major objective of this study is to investigate the dynamic behaviors of track due to the deterioration characteristics of ballast for servicing tracks by the field test. The durability of ballast plays an important role in the track behaviour. To estimate the deterioration characteristics of ballast, several tests have been carried out by several shcolars. The deterioration characteristics of ballast is one of the most important factor in the dynamic behaviour of track and its life. In this paper abrasion/breakage characteristics of ballast is studied to predict the effect of physical ballast characteristics on ballast track. To reveal deterioration characteristics of ballast, the field test were carried out. The deterioration characteristics, studied in this paper, is applied to the dynamic behaviour of track in various conditions.

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A study on the Dynamic Behaviors of Track due to Deterioration characteristics of Ballast(II) (자갈도상의 노후화에 따른 궤도구조의 동적거동에 관한 연구(II))

  • Seo Su-Euen;Park Yong-Gul;Choi Jung-Youl
    • Proceedings of the KSR Conference
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    • 2005.11a
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    • pp.854-859
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    • 2005
  • The major objective of this study is to investigate the dynamic behaviors of track due to the deterioration characteristics of ballast for servicing tracks by the field test. The durability of ballast plays an important role in the track behaviour. To estimate the deterioration characteristics of ballast, several tests have been carried out by several shcolars. The deterioration characteristics of ballast is one of the most important factor in the dynamic behaviour of track and its life. In this paper abrasion/breakage characteristics of ballast is studied to predict the effect of physical ballast characteristics on ballast track. To reveal deterioration characteristics of ballast, the field test were carried out. The deterioration characteristics, studied in this paper, is applied to the dynamic behaviour of track in various conditions.

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A Study on the Characteristics of Reinforcing Steel according to Specification and Diameter (철근의 강종 및 직경 변화에 따른 부식특성에 관한 연구)

  • Lim, Jae-won;Jee, Nam-Yong;Yoon, Sang-Chun;Choi, Jin-man
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2003.11a
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    • pp.53-58
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    • 2003
  • Concrete structures move wholly with concrete and rebar, so they endure external force, but recently the embedded rebar in concrete has been corroded by environmental, physical and chemical factors, the embedded rebar corrosion influences concrete structure to deteriorate structure capacity. To revaluate effect to deterioration of concrete structure according to corrosion of rebar, the researcher mostly examined into corrosion rebar and complex relation of concrete. In that there are flexural strength deterioration of corrosion concrete structure and the bond strength of concrete. But It has not sufficiently studied about physical characteristic of corrosion rebar itself. In this study I will compare specification of rebar through corrosion experiment with corrosion ratio of rebar according to diameter and revaluate. And will investigate the effect to strength characteristic of rebar according to corrosion ratio.

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A Study on the Characteristics of Reinforcing Steel according to Specification and Diameter (철근의 강종 및 직경 변화에 따른 부식특성에 관한 연구)

  • 임재원;지남용;윤상천;최진만
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2003.05a
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    • pp.53-58
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    • 2003
  • Concrete structures move wholly with concrete and rebar, so they endure external force, but recently the embedded rebar in concrete has been corroded by environmental, physical and chemical factors. the embedded rebar corrosion influences concrete structure to deteriorate structure capacity. To revaluate effect to deterioration of concrete structure according to corrosion of rebar, the researcher mostly examined into corrosion rebar and complex relation of concrete. In that there are flexural strength deterioration of corrosion concrete structure and the bond strength of concrete. But It has not sufficiently studied about physical characteristic of corrosion rebar itself. In this study I will compare specification of rebar through corrosion experiment with corrosion ratio of rebar according to diameter and revaluate. And I will investigate the effect to strength characteristic of rebar according to corrosion ratio.

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The biodeterioration and conservation of stone historical monuments (석조문화재의 생물학적 손상과 보존방안)

  • Chung, Yong-Jae;Seo, Min-Seok;Lee, Kyu-Shik;Han, Sung-Hee
    • 보존과학연구
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    • s.24
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    • pp.5-28
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    • 2003
  • Stone has been one of the most intensely studied materials in conservation. Understanding the deterioration of stone needs various knowledge in different mineralogical and physical characteristics and its weathering response under different climate and environment. The alteration and weathering of stone is affected by natural or artificial elements whether they are physical, chemical or biological damaging factors. It can be said that the bio deterioration of stone is coupled with every environmental factors, which induce decomposition of stone structure, either directly or indirectly as a form of catalysis. Many elements contribute to the deterioration of stone monuments and other objects of cultural value such as pagoda, stature of Buddha, etc. This report concentrates on the action of biodeteriorative factorsincluding bacteria, algae and higher plants. Preventive and remedial methods and a selection of chemical treatments are also described.

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Deterioration Factors of Agricultural Hydraulic Structures (농수로 구조물의 내구성 저하 요인)

  • 조성현;김진만;김기동;고만기;김종옥
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.10a
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    • pp.647-650
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    • 1999
  • Deterioration of agricultural hydraulic structures(AHS), which are under harsh environmental conditions, is more sever than other ordinary structures. To investigate the deterioration factors of AHS, various physical and chemical analyses are performed. The porosity of AHS increases more rapidly than ordinary structures because they are subject to frequent water permeation and water-soluble materials are easily emitted to surface area. Thus, AHS are tend to be damaged by freezing and thawing more easily due to the increase of water containment inside concrete.

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A Preliminary Study on Housing Performance Indicators Evaluating the level of Deterioration of Apartments (아파트 노후도 평가지표 개발을 위한 기초연구)

  • Cho, Sung-Heui;Lee, Tae-Kyung
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2008.04a
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    • pp.225-230
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    • 2008
  • High-rise and high-density apartment complexes has been built and supplied on a large scale in the metropolis and metropolitan areas since 1980s in order to solve housing shortage in cities. Recently they are raising deterioration problems for aging more than 20 years. moreover, those problems show very special characters such as simultaneity and a large scale. The purpose of this study is to propose a direction for the development of the evaluating indicators to measure the level of deterioration of apartments. The level of deterioration of apartments can be evaluated by housing performance. In order to evaluate the deterioration comprehensively, the housing performance indicators should be developed on the social, economical, and physical dimension. This study analyzed the concept of the apartment deterioration and compared housing performance indicators through literature review. First of all, when considering various factors in the evaluation of the deteriorated apartments, such as evaluating ranges, attributes and dimensions, housing performance indicators should be structured with the hierarchical framework. Second, housing performance indicators evaluating the level of deterioration of apartments should include social, psychological, and cultural aspects of home environments in order to understand adequately the attitude of the middle class toward services that apartments provide. Third, in previous researches, most criteria have been developed and weighted based on only expert opinions regarding performance indicators. So, It is necessary to include residents' opinions in developing performance indicators since they can provide more practical and feasible aspects the experts could not experience or understand.

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Material and Deterioration Characteristic Analysis for Inscribed Stones of Naksan Mountain Area of the Hanyangdoseong(Seoul City Wall), Korea

  • Lee, Myeong Seong;Kim, Yuri;Choie, Myoungju;Yoo, Ji Hyun;Ahn, Yu Bin
    • Journal of Conservation Science
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    • v.36 no.1
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    • pp.60-72
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    • 2020
  • The Inscribed stones of Hanyangdoseong has been weathered for a long time because of external environment and living organisms. To establish a long-term conservation-management strategy for the inscription stones, the material characteristics of the inscription stones of Naksan Mountain Area were identified, and its deterioration state was diagnosed. Consequently, it was confirmed that the Inscription stones of Naksan Mountain Area mainly comprised coarse-to medium-grained pinkish granite and biotite granite, and, in part, comprised reddish granite, quartz porphyry, and aplite. Presently, the Inscription stones of Naksan Mountain Area, Hanyangdoseong, is undergoing a considerable decrease in physical properties because of physical, chemical, and biological weathering. Moreover, it has been confirmed that the type of damage, such as blistering, soiling, and dicolouration, on the surface shows a significantly high deterioration rate, and that conservation treatment might be required in future. In addition, because the possibility of damage recurrence is high even after the treatment, the conservation state must be regularly monitored.

Petrographic Characteristics and Deterioration Evaluation of the Rock-carved Seated Buddha at Bugmireugam Hermitage in Daeheungsa Temple of Haenam, Korea (해남 대흥사 북미륵암 마애여래좌상의 암석기재적 특성과 손상도 평가)

  • Cho, Ji Hyun;Lee, Chan Hee
    • Economic and Environmental Geology
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    • v.52 no.6
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    • pp.617-626
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    • 2019
  • In this study, we investigated the petrographic characteristics and physical property of the Rock-carved Seated Buddha at Bugmireugam hermitage of Daeheungsa temple in Haenam. The Buddha Statue was carved on micrographic granite, and the rock was composed of the fine quartz encircled by orthoclase. The results of diagnosis for deterioration evaluation have shown a highly damage rate of black contaminants (8.4%) and crack index (6.6). The ultrasonic velocity have detected SW (slightly weathered) grade of weathering coefficient (mean 0.18). Various weathering factor on the surface of the Buddha Statue was affected by precious shelter, and physical property with ultrasonic was directly influenced by the structural characteristics and fissure of host rock.

Prediction Model of Chloride Penetration in Concrete Bridge Deck Considering Environmental Effects (대기 환경조건을 고려한 콘크리트 교량 바닥판의 염소이온 침투 예측 모델)

  • Kim, Eui-Sung
    • Journal of the Korean Society of Safety
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    • v.23 no.4
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    • pp.59-66
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    • 2008
  • Recently, the deterioration of reinforced concrete structures, primarily due to corrosion of steel reinforcement, has become a major concern. Chloride-induced deterioration is the most important deterioration phenomenon in reinforced concrete structures in harsh environments. For the realistic prediction of chloride penetration into concrete, a mathematical model was developed in which the effects of diffusion, chloride binding and convection due to water movement can be taken into account. The aim of this research was to reach a better understanding on the physical mechanisms underlying the deterioration process of reinforced concrete associated with chloride-induced corrosion and to propose a reliable method for estimating these effects. Chloride concentrations coming from de-icing salts are significantly influenced by the exposure conditions such as salt usage, ambient temperature and repeated wet-dry cycles.