• Journal of Korean Society of Water and Wastewater
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• v.16 no.6
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• pp.686-699
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• 2002

The purpose of this study is to estimate deterioration factors and weighting factors in pipe network which each local self-governments takes rehabilitation and replacement work present time. Deterioration factors in pipe network are able to effected of specific province or location related with water supply. Most of water supply pipes are laid under the ground, it is hard to quantify deterioration degree of water system. Moreover, the timing and economic limitation and insufficient information on the spot survey gives a difficulty to look over how old water supply system is. Accordingly, this study collects and analyses five data as the laying environment, visual analysis, analysis of soil contents, analysis of pipe material, and questionary survey data in water pipe of A city. The deterioration factor estimates 14 factors with excavation and experimental analysis and 9 factors without excavation and experimental analysis. Also, the weighting factors are estimated by using the multiple linear regressions and the linear programming. The estimated deterioration factor and weighting results are compared the analysis result of visual, pipe material, and soil contents with the Probabilistic Neural Network Model. Consequently, the model results of estimated 9 factors in this study and 14 factors show the 1-2% difference. The result show that the proposed model could be used to decide the deterioration condition of pipe line with real excavation and experimental analysis.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.5
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• pp.15-21
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• 2008

The purpose of this study is to estimate deterioration assessment for weighting factors in pipe network for which each local selfgovernment takes rehabilitation and replacement work at present time. Deterioic hierarchy process(AHP), calculates the weighting factors. The appropriate marks matrix of sixteen deterioration factors are made for the precise decision standard of pipe condition through the result of this analysis. The marks matrix of sixteen deterioration factors can solve the complicated decision making problems of pipe rehabilitation workration factors in the pipe network might be influenced by local factors, such as province, location, or land use, in water supply systems. In this study, the sixteen deterioration factors are determined suitable for domestic situation based on the pipe deterioration factor data inside and outside of the country. Also, we select persons in charge of calculating the detail weighting factors and do survey about important level of each deterioration factors. Delphi method, a question survey method applying the analyts.

• Proceedings of the Korea Concrete Institute Conference
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• 1994.04a
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• pp.243-248
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• 1994

The purpose of this study is to develop Deterioration Diagnosis System for the Reinforced Concrete Structure which can be used preliminary in determining the factors causing deterioration by simple inspection and mapping of the indicators of deterioration. Total 29 items compromising material, structural and constructional factors causing deterioration were considered in this system. Also the indicators of deterioration were subdivided into 54 items such as concrete crack pattern and steel corrosion etc. Each indicator of deterioration was quantatified by allocating and giving grade to each item which has extra weight according to its conscquence. Satisfactory results were obtatined by applying this Diagnosis system to the indicators of deterioration in ref. [3]. Further research was required on the indicators of deterioration in construction site to enhance the field applicability of this system.

• Journal of Conservation Science
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• v.38 no.4
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• pp.265-276
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• 2022

A long-term monitoring investigation at Sarushima Battery (Kanagawa, Japan), which is one of the modernization heritages was conducted from 2017.06 to 2020.12. The investigation of the temperature and relative humidity (RH), measurement of the amount of brick decay, and X-ray diffraction analysis of the brick decay was conducted to understand in detail the environment in which the historical brick structure, the state of deterioration, identify the factors of deterioration. Furthermore, it was discussed whether the suitability of these investigation methods for assessing the status, identifying the level of deterioration and the factors that led to deterioration at the historical brick heritages. It was found that the brick deterioration at the site progressed especially in two periods: in April, and from June to August. These periods coincided with the period when the RH inside the structure decreased, and the Toyo-gumi bricks were in the process of absorbing moisture. Several different types of salts were detected in brick decay, especially thenardite, which is considered highly hazardous and destructive during periods when the amount of brick decay increased. Therefore, the RH in the structure and the salts present in the bricks were identified as one of the factors in the deterioration of the bricks at the site. The methods used in this study are appropriate as the initial survey methods for investigating the current conditions and identifying the causes of deterioration because it is possible to understand the environment within the modernization heritages, grasp the details of deterioration progression, and identify the characteristics of deterioration progression and its factors through long-term investigation using the simple methods.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.11a
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• pp.21-26
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• 2008

We investigate the various factors such as earthquake, fire, flood and deterioration factors such as carbonation, salt attack, freezing thawing, alkali-aggregate reaction effects on the school facilities. As the consequence of this study we can see that there are very relative relation between deterioration factors and disaster factors. It is the aim of this study to investigate the site analysis damaged by disaster and deterioration factors of school facilities.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.667-672
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• 2002

Concrete cooled to very low temperature cyclically is deteriorated by ice formation in micro-pores. Although the factors to the deterioration are various, storage at very low temperature is mentioned as one of the factors. In practice, storage of cryogenic structure is kept at very low temperatures, and as such, it is important to take into consideration the influence of storage at such low temperature on the deterioration of concrete. Thus, in this study, the influence of storage on the deterioration of concrete at minimum temperatures taking into consideration the different W/C and air content.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04a
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• pp.391-396
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• 1998

The concrete structures are hardly ever built under ideal conditions. So many defects may occur for a various reasons such as unsuitable and defective materials, construction methods, poor workmanship, particular structural form and prevailing weather conditions. Some structural form can greatly increase the risk of occurrence of defects. Therefore we investigated the actual condition of the deterioration factors for reinforced concrete apartment, which was composed of 85 apartments with various building ages in different regions with five evaluation the deterioration factors of apartment building to establish the overall evaluation system of deterioration degree for reinforced concrete apartment in Korea.

• Journal of the Korea institute for structural maintenance and inspection
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• v.3 no.2
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• pp.185-190
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• 1999

It is difficult to estimate for deterioration of exterior wall by infrared thermography, because of amount of infrared-ray radiation effected by environmental factors such as temperature properties of materials, the outside air and the amount of solar radiation. Therefore we measured the distribution of temperature by times in the same reinforced-concrete structure in order to reduce problems, occasioned by environmental factors, then we analyzed physical influence factors of the infrared thermography. It is the aim of this study to suggest basic data with regard to method of estimation-system for deterioration of exterior wall in reinforced-concrete structures.

• 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.

• Corrosion Science and Technology
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• v.4 no.5
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• pp.207-210
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• 2005

Coating performance of various coating systems including chlorinated rubber and epoxy/urethane used most for steel structures of highway in Korea, was evaluated by exposing test specimen to complex deterioration factors such as ultraviolet ray, moisture, freeze-thaw cycle and salt. Deteriorated specimens were evaluated by chalking and rust grades according to ASTM, and measurement of color differences and adhesion. In overall coating performances such as corrosion resistance, photochemical stability, and adhesion, ceramic/ urethane, moisture-curable urethane/ urethane, etc. were superior. As for other coating materials tested in this study, superior materials against certain deterioration factors may be inferior against other factors. Accordingly, in order to select suitable maintenance coating materials for the use, it is thought that investigation of suitability through experiment should precede selection of materials, especially for unusual coatings or paints.