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칼슘 용출 열화에 의해 표면이 손상된 콘크리트 부재의 구조적 거동에 관한 해석적 연구

Analytical Study on Structural Behavior of Surface Damaged Concrete Member by Calcium Leaching Degradation

  • 최윤석 (한국과학기술원 응용과학연구소) ;
  • 장용환 ((재)한국건설품질연구원) ;
  • 최소영 (강릉원주대학교 토목공학과) ;
  • 김일순 (한국시설안전공단) ;
  • 양은익 (강릉원주대학교 토목공학과)
  • 투고 : 2014.04.23
  • 심사 : 2014.05.26
  • 발행 : 2014.07.30

초록

다양한 열화 인자에 의해 저감된 콘크리트의 내구성은 구조물의 구조적 성능과 사용 수명에 부정적인 영향을 미치게 되며 콘크리트 연구 분야 중에서도 매우 중요하고 매력적인 주제라고 할 수 있다. 이러한 이유로 콘크리트의 내구성과 관련된 많은 연구들이 발표되었으나 물리-화학적 열화에 기인하는 콘크리트의 본질적인 물성 변화에 주된 초점이 맞춰져 왔으며, 콘크리트 내구성과 구조물의 구조적 성능 사이의 관계 정립은 아직 미흡한 실정이다. 본 연구에서는 콘크리트의 강도 감소에 원인이 되는 칼슘 용출 열화를 적용하였으며, 열화 정도에 따른 구조적 거동을 평가하기 위하여 열화 손상을 입은 콘크리트 부재의 압축 및 휨 거동 실험을 수행하고 그 결과를 비선형 유한요소해석 결과와 비교 분석하였다. 연구 결과에 따르면 칼슘 용출 열화는 콘크리트의 압축 강도를 저하시키며, 열화가 진행됨에 따라 취성 거동에서 연성 거동으로 변화되는 경향을 나타냈다. 또한 열화에 의한 압축 영역의 손상 정도가 심화될수록 RC 부재의 내하력과 강성은 저하되었으며, 이러한 구조적 거동은 ABAQUS의 CDP 모델을 사용한 비선형 유한요소해석의 결과와도 비교적 잘 일치하였다.

Durability is one of the most important and attractive subjects in concrete research field because not only durability of concrete is reduced by various degradation factors but also its reduction adversely influences the structural performance and service life of concrete structure. For this reason, a considerable amount of papers associated with concrete durability have been published and those researches were mainly focused on the changes of intrinsic properties of concrete due to chemicophysical degradations. However, the relationship between durability of concrete and structural behavior of concrete member has not been well established yet. In this study, calcium leaching degradation, a cause of concrete strength reduction, was dealt with. The experiments of compressive and flexural behavior of degraded concrete member were performed to evaluate the characteristics of structural behavior according to degradation level. Finally, the results from the experiments were compared with those obtained from nonlinear FEM analysis. The results from this study clearly showed that leaching degradation leads to decrease in compressive strength and compressive behavior evolves from brittle to ductile failure pattern during the degradation process. Load capacity and flexible rigidity of the degraded RC member decreased when the degradation level increased, in compressive zone. Additionally, it was found that the values from nonlinear FEM analysis, CDP model in ABAQUS, coincided well with the experimental results.

키워드

참고문헌

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피인용 문헌

  1. Analysis and Prediction of Highway Bridge Deck Slab Deterioration vol.19, pp.2, 2015, https://doi.org/10.11112/jksmi.2015.19.2.068
  2. Characteristics of Calcium Leaching Resistance for Concrete Mixed with Mineral Admixture vol.20, pp.4, 2016, https://doi.org/10.11112/jksmi.2016.20.4.059
  3. 국내 도로교량 바닥판 열화모델 제안 및 교체 수요 예측 vol.21, pp.4, 2014, https://doi.org/10.11112/jksmi.2017.21.4.061
  4. 칼슘용출 열화 조건에서 광물질 혼화재를 사용한 RC부재의 휨 거동에 관한 실험적 연구 vol.22, pp.2, 2014, https://doi.org/10.11112/jksmi.2018.22.2.016
  5. 고밀도 폐유리를 잔골재로 사용한 RC 부재의 휨거동에 관한 해석적 연구 vol.24, pp.1, 2014, https://doi.org/10.11112/jksmi.2020.24.1.88
  6. An experimental study on the flexural behavior of RC member under long-term calcium leaching degradation vol.6, pp.1, 2021, https://doi.org/10.1080/24705314.2020.1824668