• Title/Summary/Keyword: 철근콘크리트구조물

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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.

Experimental Techniques of Small-Scale Models for Reinforced Concrete Structural Researches (철근콘크리트구조 연구를 위한 소축적 구조모형실험기법)

  • Kim, Woo;Kim, Dae-Joong;Kang, Sung-Hoo
    • Magazine of the Korea Concrete Institute
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    • v.3 no.4
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    • pp.133-142
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    • 1991
  • When the behavior of a prototype concrete structure is studied through small-scale model experiments, it is necessary to reproduce all significant physical characteristics on either an one-to-one basis or a specific similitude relationship. Any distortion of similitude must be understood and its effect must be predictable. This paper focuses on improved physical modeling techniques for small-scale reinforced concrete structures. Particular emphasis is placed on the development of a model concrete mix to accurately model the important properties of full-scale prototype concrete. Four types of model reinforcement with different bond characteristics are also studied by testing twenty simple beams. The information obtained will be of immediate use to engineers contemplating small-scale modeling of reinforced concrete structures.

Size Effect Analysis for Shear Strength of Large Reinforced Concrete Beams (대형 철근콘크리트 보의 전단강도에 대한 크기효과 해석)

  • 한상호
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.12 no.3
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    • pp.345-352
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    • 1999
  • 철근콘크리트 보의 전단강도에 대한 크리효과는 다른 각종 강도에 대한 크기효과에 비해 현저히 나타난다는 것이 많은 실험적 연구로부터 입증되었으며, 이를 배경으로 세계 여러 나라의 전단강도에 대한 설계 기준식들이 전단강도의 크리효과를 반영하고 있는 실정이다. 그러나, 철근콘크리트 구조물이 점점 대형화됨으로써 이와 같은 설계 기준식의 실험적 검토는 사실상 불가능하게 될 것이다. 본 연구에서는 파괴역학에 근거한 비선형 유한요소프로그램을 이용하여 전단보강철근이 없는 대형 철근콘크리트 보의 전단강도에 대한 크기 효과를 재현해 보았다. 또한, 해석 및 실험결과를 이용하여 크기효과가 고려된 몇 가지 대표적인 전단강도식과 비교하였다.

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The Sensitivity Evaluation of Probability Variables to Durability Design of the RC Structures (철근콘크리트 구조물 염해 내구설계에 있어서 설계확률변수의 민감도 평가)

  • Park, Dong-Cheon;Oh, Sang-Gyun
    • Journal of Navigation and Port Research
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    • v.33 no.3
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    • pp.235-240
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    • 2009
  • Simulation method based on probability was developed to evaluate the durability of reinforced concrete structures about chloride attack. The effects of the probability parameters(surface chloride ion concentration, initial combined chloride ion concentration, the depth of cover thickness of concrete, and the chloride ion diffusion coefficient), probability distribution function and it's variation were calculated using the Monte Carlo method and Fick's 2nd law. From the durability design method proposed in this study, the following results were obtained. 1) The effects of the distance from the coast and the chloride ion diffusion coefficient to the corrosion probability were quite high. 2) The effect of the variation of each parameters was relatively low.

Effect of Impressed Current System for Corrosion Protection of Rebars in Concrete (콘크리트 중의 철근 부식 억제를 위한 외부전원법의 효과)

  • Moon, Han-Young;Kim, Seong-Soo;Kim, Hong-Sam
    • Magazine of the Korea Concrete Institute
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    • v.11 no.2
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    • pp.221-230
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    • 1999
  • Corrosion of rebars can occur if there are cracks, moisture and availability of oxygen or carbonation proceeds, chloride penetrates and diffuses in concrete. Once rebars in concrete corrodes, subsequently accompanied with scaling, spalling in concrete cover. As a result of them, the RC structure is seriously deteriorated. In this study, theoretical review and experiments for cathodic protection(CP) have been performed to control corrosion of rebars in concrete contained chlorides and pre-crack. For CP the impressed current system was applied, the protection effect was investigated when rebars was directly contacted with salt water due to crack and open to much chlorides in concrete. In order to investigate the effect of protection, when CP was energized for 1 year, half-cell potential, potential-decay with current density, corrosion ratio, etc. were measured. With the cathodic protection by impressed current system, the depolarized values of all specimen were met NACE Standard, the effect of 34~84% of the ratio of corrosion area and 84~86% of cross-section reduction were calculated.

Repair LCC Evaluation of RC Structures through the FEM Analysis of Chloride Ion Penetration (염소이온 침투 FEM 해석을 통한 RC구조물의 보수 LCC 평가)

  • Lee, Han-Seung
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.10 no.1
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    • pp.223-230
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    • 2006
  • In this paper the method for repair LCC evaluation of reinforced concrete structures deteriorated by chloride attack was constructed. Also, the FEM analysis for chloride ion penetration into concrete was conducted to evaluate the repair LCC which was decided by the number of repair times including early stages of construction and repair construction during the service life of structures. As a result, the number of repair times is obtained from the comparing the concentration of the chloride ion in a rebar position, and the critical chloride ion concentration of rebar corrosion through the FEM analysis considering the kind of repair materials and methods. Also, the repair LCC could be calculated by the number of repair times during the service life of structures.

Design of Fire-Resistance in RC Structure Buildings (콘크리트 구조물의 내화설계)

  • 김화중
    • Magazine of the Korea Concrete Institute
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    • v.14 no.2
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    • pp.30-36
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    • 2002
  • 콘크리트가 화재에 노출될 경우 가열에 의한 재질의 노화 및 열팽창에 의한 열응력의 발생에 따라 주요구조부인 기둥 및 보에 큰 손상이 생기게 되어 그 내력은 크게 저하하게 된다. 철근 콘크리트 구조물의 화재 상황을 조사해 보면 (그림 1)과 같이 열응력에 의한 기둥의 전단파괴, 보의 휨파괴 및 부재의 폭열 등이 보여진다.(중략)

Cost-effective Reliability of RC structure in Korea under earthquake (철근콘크리트구조의 경제적인 내진 신뢰성)

  • ;Alfred H-S. Ang
    • Magazine of the Korea Concrete Institute
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    • v.9 no.5
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    • pp.137-148
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    • 1997
  • 지진이 발생하는 환경에서 철근콘크리트구조의 신뢰성을 수명주기비용에 근거하여 체계적으로 평가하는 방법을 제시하였다. 구조물의 기능성과 경제적인 효용성을 나타내기 위하여 각각 손상확률과 평균수명 주기비용의 개념을 사용하였다. 생애주기 동안 발생할 수 있는 지진에 의하여 구조물이 입게 될 손상을 보상하기 위하여 소요되는 평균손상비용을 평균수명주기비용의 주요 항목으로 고려하여 분석하였다. 구조물의 다양한 손상상태에서 손상비용을 나타내기 위해 요구되는 비용함수는 Park-Ang 손상지수의 중앙값을 독립변수로 하는 함수로 가정하였다. 지진에 의한 구조물의 손상해석은 UCI에서 개발된 SMART-DRAIN의 시뮬레이션기법을 사용하여 그 불확실성을 고려하였다. 제시된 방법을 현행 규준에 의하여 설계된 7층 사무실 건물에 적용하여 그 가능성을 살펴보았다.