• Title/Summary/Keyword: 잔존물

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Remaining Service Life Estimation Model for Reinforced Concrete Structures Considering Effects of Differential Settlements (부등침하의 영향이 반영된 철근콘크리트 구조물 잔존수명 평가모델)

  • Lee, Sang-Hoon;Han, Sun-Jin;Cho, Hae-Chang;Lee, Yoon Jung;Kim, Kang Su
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.24 no.1
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    • pp.133-141
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    • 2020
  • Korea Infrastructure Safety and Technology Corporation (KISTEC) specifies that the safety inspection and precise safety diagnosis of concrete structures shall be conducted in accordance with the 'Special Law on Safety Management of Infrastructure'. The detailed safety inspection and precise safety diagnosis guidelines presented by KISTEC, however, gives only the grade of members and structures, and thus it is impossible to quantify remaining service life (RSL) of the structures and to quantitatively reflect the effect of differential settlements on the RSL. Therefore, this study aims to develop a RSL evaluation model considering the differential settlements. To this end, a simple equation was proposed based on the correlations between differential settlements and angular distortion, by which the angular distortion of structures was then reflected in nominal strengths of structural members. In addition, the effects of the differential settlements on the RSL of structures were analyzed in detail by using the safety diagnosis results of actual concrete structure.

Remaining Service Life Prediction of Concrete Structures under Chloride-induced Loads (염해환경하의 콘크리트 구조물의 잔존수명 예측)

  • Song, Ha-Won;Luc, Dao Ngoc The
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.1037-1040
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    • 2008
  • In order to predict the remaining life of marine concrete structures under climatic loads, it is necessary to develop an analytical approach to predict the time and space dependent deterioration of concrete structures due to mainly chloride attack up to corrosion initiation and additional deterioration like cracking of cover concrete. This study aims to introduce FEM model for life-time simulation of concrete structures subjected to chloride attack. In order to consider uncertainties in materials as well as environmental parameters for the prediction, Monte Carlo Simulation is integrated in that FEM modeling for reliability-based remaining service life prediction. The paper is organized as follows: firstly general scheme for reliability-based remaining service life of concrete structures is introduced, then the FEM models for chloride penetration, corrosion product expansion and cover cracking are briefly explained, finally an example is demonstrated and the effects of localization of chloride concentration and corrosion product expansion on service life using above model are discussed.

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Study on the Effect of the ABC Dry Chemical on Wood in Pyrolysis (ABC 분말소화약제의 열분해 시 목재에 미치는 영향에 관한 연구)

  • Ko, Wang-Youl;In, Se-Jin
    • Fire Science and Engineering
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    • v.32 no.3
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    • pp.1-7
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    • 2018
  • This study the effect of pyrolysis products ABC dry chemical and of monoammonium phosphate on wood surface. When the pyrolysis product was removed from the wood surface, monoammonium phosphate was removed due to the high viscosity of the transparent pyrolysis product, but the ABC dry chemical was removed in a lump form. Thermal analysis showed that the pyrolysis characteristics of each sample were similar but the weight of pyrolysis residue was 55.9% for ABC dry chemical and 25.2% for monoammonium phosphate. The additives added to the ABC dry chemical also affect the weight of the pyrolysis residue and the fire protection effect of metaphosphoric acid.

A Study on the Survived Records Related to Building Cheongnamdae (청남대 건립 관련 잔존 기록물 조사 연구)

  • Chung, Sanghee
    • The Korean Journal of Archival Studies
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    • no.47
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    • pp.161-193
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    • 2016
  • Cheongnamdae is public building which was built in 1983. Cheongnamda had been used for the exclusive villa for Presidents of Korea from then until 2003 when it opened to the public. Because of public building, public records would have been produced during the construction process. The records of public institutions are generally managed and destroyed according to retention schedule. Considering the retention schedule of those days, it is more likely that most of records which would show the accountability about building Cheongnamdae do not remain. But regardless of retention period, those records may be left, so we need to confirm existence of the records. The purpose of this study is to examine whether the records related to the construction remain or not. For the examination, I make a list of the records which are supposed to be created during the construction process. Then I identify whether those records are preserved in records-creating institutions or national archives or not. And I suggest the selection strategy of the records of existing public buildings and show the direction for managing the records of public buildings to be built.

Applicability of Impact-Echo Method for Assessment of Residual Strength of Fire-Damaged Concrete (화해된 콘크리트의 잔존 강도 평가에 있어서 충격-반향 기법의 적용성)

  • Shin, Sung-Woo;Kim, Seung-Yong;Kim, Jeong-Su
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.17 no.5
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    • pp.105-112
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    • 2013
  • In this study, the applicability of impact-echo method for assessment of residual strength of fire-damaged concrete is investigated. A series of standard fire test is performed to obtain fire-damaged concrete specimens. Impact-echo tests are executed on the specimens and the responses are analyzed. Compressive strengths of the fire-damaged concrete are evaluated and correlated with the ultrasonic wave velocities determined from the impact-echo responses. The effectiveness of impact-echo based ultrasonic wave velocity measurement for assessment of residual strength of fire-damaged concrete is discussed.

Characteristics of Habitats and Small Rodent Populations caused by Different Remnant Treatments on Forest Floor in Fired Coniferous Forest (산불피해지역에서 임상잔존물의 처리에 따른 서식환경과 소형 설치류 개체군 특성)

  • Lee, Eun Jae;Lee, Woo-Shin;Lee, Young-Geun;Lee, Myung-Bo;Rhim, Shin-Jae
    • Journal of Korean Society of Forest Science
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    • v.95 no.6
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    • pp.711-715
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    • 2006
  • This study was conducted to clarify the characteristics of habitats and small rodent populations between remnant removed and left areas caused by different remnant treatment on forest floor in fired coniferous forest, Mt Gumbong, Samcheok, Korea, There were higher value of variables of understory coverage, snags, downed coarse woody debris (CWD) in natural restored area. Mean number of captured individuals and body weights of Apodemus peninsulae and Eothenomys regulus were more higher in remnant left area than in removed area, The differences in density and body weight of small rodents would be related with habitats between both study areas. The remove of remnant trees on the forest floor would not be good for small rodents. The more detailed and long-term researches would be needed for proper restoration in fired forest area.

Investigation of an Apartment Fire - Site Surveys and Burn Tests for Estimation of the Progress on Initial Fire Spread - (공동주택의 화재조사 - 현장조사 및 연소실험에 의한 초기 화재확대과정 추정 -)

  • Nam, Dong-Gun;Hasemi, Yuji
    • Fire Science and Engineering
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    • v.23 no.4
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    • pp.120-129
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    • 2009
  • Identification of the exact cause of a building fire is generally difficult, because the source and initially ignited objects are often severely damaged or even lost during the early stages of the fire. We made an experimental attempt to reasonably estimate the burning during the very early stages of a fire, and identify its source and causes. The case we studied was an apartment fire, which occurred in Tokyo, in July 2002. The fire was extinguished just after flashover, and the on-site investigations suggested the fire started from the TV and TV stand, which had been damaged so severely that it was difficult to conclude that the TV was the ultimate cause of the fire, simply from the on-site investigation. We conducted a series of burn tests using a TV and other products identical to those actually used in the apartment. Tests were set-up and procedures were carefully studied to recreate the conditions of the articles that remained, and of the room itself. The tests demonstrated that the conditions in the apartment could be recreated only when the fire started inside the TV and came into close contact with dresser.