• Title/Summary/Keyword: deterioration prediction

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A Study on the Deterioration Prediction Method of Concrete Structures Subjected to Cyclic Freezing and Thawing (동결융해 작용을 받는 콘크리트 구조물의 내구성능 저하 예측 방법에 관한 연구)

  • Koh, Kyung-Taeg;Kim, Do-Gyeum;Cho, Myung-Sung;Son, Young-Chul
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.5 no.1
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    • pp.131-140
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    • 2001
  • In general, the deterioration induced by the freezing and thawing cyclic in concrete structures often leads to the reduction in concrete durability by the cracking or surface spalling. If it can prediction of concrete deterioration subjected to cyclic freezing and thawing, we can rationally do the design of mix proportion in view of concrete durability and the maintenance management of concrete structures. Therefore in this study a prediction method of deterioration for concrete structures subjected to the irregular freezing and thawing is proposed from the results of accelerated laboratory freezing and thawing test using the constant temperature condition and the in-situ weathering data. Furthermore, to accurately predict the concrete deterioration, a method of modification for the effect of hydration increasing during rapid freezing and thawing test is investigated.

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Development of Optimal Rehabilitation Model for Water Distribution System Based on Prediction of Pipe Deterioration (II) - Application and Analysis - (상수관로의 노후도 예측에 근거한 최적 개량 모형의 개발 (II) - 적용 및 분석 -)

  • Kim, Eung-Seok;Park, Moo-Jong;Kim, Joong-Hoon
    • Journal of Korea Water Resources Association
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    • v.36 no.1
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    • pp.61-74
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    • 2003
  • This study(II) apply to the A city by using the optimal rehabilitation model based on the deterioration prediction of the water distribution system proposed the study(I). The deterioration prediction model divides factors into 14 factors with digging and experiment and 9 factor without digging and experiment and calculate the deterioration degree. The application results of the deterioration prediction model show that a difference of the deterioration degree according to factor numbers is within 1~2%. Also, the model can predict the deterioration degree of each pipe without digging and experiment. The optimal rehabilitation model is divided into the optimal residual durability of each deterioration factor and budget constraint or not. The application result is as follow: the rehabilitation time and cost increase according to the increasing of the optimal residual durability. When compared the model with budget constraint and model without budget constraint, the former model increase the cost of total contents. In case of budget constraint, the increasing tendency is concluded that the pipe rehabilitation is executed in same budget every year in condition that every rehabilitation cost do not exceed the every year budget within the optimal residual durability.

Deterioration Prediction Model of Water Pipes Using Fuzzy Techniques (퍼지기법을 이용한 상수관로의 노후도예측 모델 연구)

  • Choi, Taeho;Choi, Min-ah;Lee, Hyundong;Koo, Jayong
    • Journal of Korean Society of Water and Wastewater
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    • v.30 no.2
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    • pp.155-165
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    • 2016
  • Pipe Deterioration Prediction (PDP) and Pipe Failure Risk Prediction (PFRP) models were developed in an attempt to predict the deterioration and failure risk in water mains using fuzzy technique and the markov process. These two models were used to determine the priority in repair and replacement, by predicting the deterioration degree, deterioration rate, failure possibility and remaining life in a study sample comprising 32 water mains. From an analysis approach based on conservative risk with a medium policy risk, the remaining life for 30 of the 32 water mains was less than 5 years for 2 mains (7%), 5-10 years for 8 (27%), 10-15 years for 7 (23%), 15-20 years for 5 (17%), 20-25 years for 5 (17%), and 25 years or more for 2 (7%).

A Study on High Speed Railway Track Deterioration Prediction (고속선 궤도틀림진전예측에 관한 연구)

  • Shim, Yun-Seop;Kim, Ki-Dong;Lee, Sung-Uk;Woo, Byoung-Koo;Lee, Ki-Woo
    • Proceedings of the KSR Conference
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    • 2010.06a
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    • pp.261-267
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    • 2010
  • Present maintenance of a high speed railway is after the fack maintenance that executes a task when measured value goes over threshold value except some planned maintenance. It is difficult from efficient management of maintenance human resource and equipment commitment because it is difficult to predict quantity of maintenance targets. Corrective maintenance is pushed back on the repair priority of other target to need repair and it is exceeded repair cost potentially. For safety and dependable track management because track deterioration prediction is linked directly with track's life and safety of train service, it is very important that track management be based on preventive maintenance. In this study, we propose statistics model of track quality to use track inspection data and forecast model for track deterioration prediction.

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IMPROVING RELIABILITY OF BRIDGE DETERIORATION MODEL USING GENERATED MISSING CONDITION RATINGS

  • Jung Baeg Son;Jaeho Lee;Michael Blumenstein;Yew-Chaye Loo;Hong Guan;Kriengsak Panuwatwanich
    • International conference on construction engineering and project management
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    • 2009.05a
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    • pp.700-706
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    • 2009
  • Bridges are vital components of any road network which demand crucial and timely decision-making for Maintenance, Repair and Rehabilitation (MR&R) activities. Bridge Management Systems (BMSs) as a decision support system (DSS), have been developed since the early 1990's to assist in the management of a large bridge network. Historical condition ratings obtained from biennial bridge inspections are major resources for predicting future bridge deteriorations via BMSs. Available historical condition ratings in most bridge agencies, however, are very limited, and thus posing a major barrier for obtaining reliable future structural performances. To alleviate this problem, the verified Backward Prediction Model (BPM) technique has been developed to help generate missing historical condition ratings. This is achieved through establishing the correlation between known condition ratings and such non-bridge factors as climate and environmental conditions, traffic volumes and population growth. Such correlations can then be used to obtain the bridge condition ratings of the missing years. With the help of these generated datasets, the currently available bridge deterioration model can be utilized to more reliably forecast future bridge conditions. In this paper, the prediction accuracy based on 4 and 9 BPM-generated historical condition ratings as input data are compared, using deterministic and stochastic bridge deterioration models. The comparison outcomes indicate that the prediction error decreases as more historical condition ratings obtained. This implies that the BPM can be utilised to generate unavailable historical data, which is crucial for bridge deterioration models to achieve more accurate prediction results. Nevertheless, there are considerable limitations in the existing bridge deterioration models. Thus, further research is essential to improve the prediction accuracy of bridge deterioration models.

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A custom building deterioration model

  • Hosny, O.A.;Elhakeem, A.A.;Hegazy, T.
    • Structural Engineering and Mechanics
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    • v.37 no.6
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    • pp.685-691
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    • 2011
  • Developing accurate prediction models for deterioration behavior represents a challenging but essential task in comprehensive Infrastructure Management Systems. The challenge may be a result of the lack of historical data, impact of unforeseen parameters, and/or the past repair/maintenance practices. These realities contribute heavily to the noticeable variability in deterioration behavior even among similar components. This paper introduces a novel approach to predict the deterioration of any infrastructure component. The approach is general as it fits any component, however the prediction is custom for a specific item to consider the inherent impacts of expected and unexpected parameters that affect its unique deterioration behavior.

Study on the Prediction of Concrete Deterioration Subjected to Cyclic Freezing and Thawing (동결융해작용을 받는 콘크리트의 열화예측에 관한 연구)

  • 고경택;이종석;이장화;조명석;송영철
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.10a
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    • pp.795-798
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    • 1999
  • Deterioration induced by the freezing and thawing in concrete often leads to the reduction in concrete durability by the cracking or surface spalling. In this paper, the deterioration prediction model for concrete structures subjected to the irregular freeze-thaw was proposed from the results of accelerated laboratory test using the constant temperature condition and acceleration factor from the in-situ weather data.

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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.

Prediction of Lifetime of Steel Bridge Coating on Highway for Effective Maintenance (고속도로 강구조물의 효율적 유지관리를 위한 도막수명예측)

  • Lee, Chan-Young;Cheong, Haimoon;Park, Jin-Hwan
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.3A
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    • pp.341-347
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    • 2008
  • Among coating systems used for steel bridge coatings on highway such as red lead-pigmented alkyd, chlorinated rubber, waterborne inorganic zinc, inorganic zinc/epoxy/urethane and inorganic zinc/epoxy/fluororesin, evaluation of deterioration degree and prediction of lifetime through regression analysis were carried out for coating systems widely used and grossly degraded. For evaluation of deterioration degree, 75 bridges on highway were selected, and evaluations were carried out according to point offering method regulated by Guideline of maintenance coating for steel bridges used in Korea Expressway Corporation. Lifetime prediction results showed 13.0~13.3 years for the whole nation, 11.8 years for urban and industrial region in the metropolitan area, 13.2 years for rural region except the metropolitan area, 13.5~13.7 years for chlorinated rubber coating systems, and 12.86 years for red lead-pigmented alkyd systems. For prediction of the rest life of coating, we tried to execute parallel translations of standard deterioration curve to current life and deterioration degree for both x and y axes, and it was thought that parallel translation for x axis corresponded to deterioration aspects in actual environment. Maximum and minimum equations were derived from standard deterioration equation by adding and subtracting error values deduced in regression analysis to/from each coefficient in order to establish maintenance coating criteria for overall steel bridges on highway. Whole domain was divided into 8 parts in order to predict the rest life of coating and optimum time of maintenance coating, and maintenance coating criteria for each 8 domains were presented.

Prediction of Carbonation Progress for Concrete Structures Considering Change of Atmospheric Environment (대기환경변화를 고려한 콘크리트 구조물의 중성화 예측)

  • Lee, Chang-Soo;Yoon, In-Seok
    • Journal of the Korea Concrete Institute
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    • v.15 no.4
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    • pp.574-584
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    • 2003
  • The most common deterioration cause of concrete structures in urban environment is carbonation. Recently, the $CO_2$ concentration and temperature at atmosphere is sharply increased with time due to global warming phenomena. In this study, the climate scenario IS92a, which was suggested by the IPCC, is used to consider temperature and atmospheric $CO_2$ concentration change in the model of service life prediction. The modified mathematical solution, which was based on the Fick's 1st law of diffusion, was used to reflect concrete materials properties such as the degree of hydration of concrete with elapsed time, and important parameters, which associated with deterioration rate. The techniques of service life prediction are developed introducing the method of reliability and stochastic concept to consider microclimatic condition in Seoul, South Korea. From the result of service life prediction, concrete containing high W/C ratio is shown fast carbonation rate due to $CO_2$ concentration increase. It is concluded that the deterioration of concrete structures due to carbonation is insignificant problem on the conditions that below W/C 55%, well curing concrete.