Journal of the Korean Recycled Construction Resources Institute (한국건설순환자원학회논문집)

Korean Recycled Construction Resources Institute (한국건설순환자원학회)
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Service Life Evaluation of RC Column Exposed to Carbonation Considering Time-dependent Crack Pattern

시간의존성 균열 패턴을 고려한 탄산화에 노출된 콘크리트의 확률론적 내구수명 평가

  • 권성준 (한남대학교 건설시스템공학과)
  • Received : 2016.03.02
  • Accepted : 2016.03.15
  • Published : 2016.03.30
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Abstract

RC(Reinfored Concrete) structures exposed to carbonation in urban city have durability degradation with extended service life and cracks in concrete causes a local accelerated carbonation. In the present work, crack effect on carbonation depth is investigated and the service life of RC structure is evaluated considering cracks from early age and time-dependent cracks based on the previous field investigation. DFP(Durability Failure Probability), safety index, and the related service life are calculated considering the time to crack width reaches to maximum crack width(0.3mm). The results with time effect on crack width show lower DFP and longer service life, which seems to be reasonable compared with conservative results from crack effect from initial stage. Furthermore, crack effect is evaluated to be insignificant on DFP and service life. The technique with time-dependent crack effect on carbonation can be effectively used for RC structure containing cracking in use.

대도시의 콘크리트 구조물은 탄산화에 노출되며 사용기간의 증가로 인해 내구성 저하를 나타내며 콘크리트에 발생하는 균열은 국부적인 탄산화 증가를 야기한다. 본 연구에서는 실태조사를 통하여 균열부의 탄산화속도를 분석하였으며, 이를 시간의존성균열과 초기재령균열로 구분하여 탄산화에 노출된 RC교각의 내구수명을 분석하였다. 실태조사 결과를 기본으로 균열이 최대 0.3mm까지 진전하고 여기에 최대 균열폭에 이르는 시간을 변수로 하여 내구성 파괴확률, 신뢰성 지수, 내구수명 등이 평가되었다. 시간의존성균열 패턴은 초기재령부터 발생한 균열보다 낮은 내구성파괴확률과 높은 내구수명을 나타내었는데, 이는 지나치게 보수적인 해석기법보다 합리적이다. 또한 피복두께가 100mm보다 클 경우, 균열에 대한 시간효과는 내구성 파괴확률 및 내구수명에 큰 영향을 미치지 못하였다. 고정 균열이 아닌 시간의존적균열을 고려한 확률론적 내구수명 해석기법은 운용 중 발생하여 균열이 발생한 구조물에 효과적으로 사용될 것이다.

Keywords

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