Journal of the Korea Concrete Institute (콘크리트학회논문집)

Korea Concrete Institute (한국콘크리트학회)
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A Study on the Thermal Crack Control of Foundation for Large Turbine

대형 터빈 기초 구조물의 온도균열 제어에 관한 연구

  • Ha, Ju-Hyung (Advanced Material R&D Team, Hyundai Institute of Construction Technology) ;
  • Cho, Yun-Gu (Advanced Material R&D Team, Hyundai Institute of Construction Technology) ;
  • Lee, Kewn-Chu (Advanced Material R&D Team, Hyundai Institute of Construction Technology) ;
  • Lim, Chang-Keun (Advanced Material R&D Team, Hyundai Institute of Construction Technology)
  • 하주형 (현대건설 연구개발본부 첨단재료연구팀) ;
  • 조윤구 (현대건설 연구개발본부 첨단재료연구팀) ;
  • 이근주 (현대건설 연구개발본부 첨단재료연구팀) ;
  • 임창근 (현대건설 연구개발본부 첨단재료연구팀)
  • Received : 2014.01.06
  • Accepted : 2014.03.31
  • Published : 2014.06.30
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Abstract

Heat of hydration of mass concrete is one of the most important factors that significantly affect structural quality and construction period. Therefore, appropriate methods to control heat of hydration are essential technologies for mass concrete construction. In this study, probability of thermal cracking was checked by thermal analysis prior to the construction of a turbine foundation in a domestic power plant. Subsequently, changes of concrete mix proportion and an effective curing method were proposed to control heat of hydration of mass concrete structures. Concrete manufactured by slag cement was proposed instead of concrete produced by ordinary Portland cement, and an automated curing method was proposed to improve the curing method using typical moist curing with blanket. The automated curing method maintains the temperature difference between center and surface of concrete below a setting value by temperature monitoring. Concrete with slag cement was used for actual construction. One of two identical turbine foundations was cured by an insulated curing method, and the other was cured by the automated curing method to compare the curing methods. And then, the effects of control of heat of hydration were evaluated based on temperature/strain monitoring and crack investigations.

최근 증가 추세에 있는 화력발전소 건설에 있어서, 터빈 기초 구조물은 규모가 매우 큰 매스콘크리트이다. 매스콘크리트의 수화열은 구조물의 품질과 공기 등에 중대한 영향을 미치는 요인 중 하나이므로, 수화열 제어를 위한 적절한 방안은 필수적이다. 이 연구에서는 국내 복합화력발전소 터빈 기초 시공에 앞서 수화열 해석을 통하여 수화열 균열 발생 가능성을 예측하고, 수화열 제어 방안으로서 콘크리트 배합 및 양생방법 변경을 제안하였다. 콘크리트 배합은 기존 1종 보통시멘트 콘크리트 배합에서 슬래그시멘트 콘크리트 배합으로 변경을 제안하였고, 기존 양생포 및 살수양생방법을 개선하기 위하여 매스콘크리트 중심부와 표면부의 온도를 모니터링하여 온도차를 일정수준 이하로 일정하게 유지시켜주는 양생자동화시스템을 적용한 양생방법을 제안하였다. 실제 시공시에는 슬래그콘크리트 배합을 사용하고, 2기의 동일한 터빈 기초 구조물에 대하여 각각 보온양생공법과 양생자동화시스템을 적용하여 양생방법에 따른 온도균열 제어효과를 비교하였으며, 2기의 매스콘크리트에서 온도, 변형률 모니터링 및 균열 조사를 통하여 수화열 제어 효과를 평가하였다.

Keywords

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