Journal of the Korea institute for structural maintenance and inspection (한국구조물진단유지관리공학회 논문집)

Korea Institute for Structural Maintenance Inspection (한국구조물진단유지관리공학회)
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Shear Characteristics of Elastomeric Bearing Rubber Deteriorated by Accelerated Heat Aging(1): Natural Rubber

가속열 노화로 열화된 탄성받침 고무재료의 전단 특성(1): 천연고무

  • 선창호 (울산대학교 건설환경공학부) ;
  • 김익현 (울산대학교 건설환경공학부)
  • Received : 2021.10.17
  • Accepted : 2021.12.01
  • Published : 2021.12.31
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Abstract

Elastometic bearings using flexible rubber materials have recently been widely applied for seismic retrofit of bridges. However, due to various factors, the aging of the rubber material progresses, which causes the shear stiffness change of the bearing, which affects the seismic performance of the bridge. For natural rubber, accelerated heat aging test was performed with variables of heating temperatures and exposure time to analyze shear characteristics. As aging progresses (i.e. increase of temperature and exposure time), the maximum shear stress and shear strain decrease. Also, the shear stiffness is greatly increased at the same shear strain. This means that the rubber material is hardened, implying that the seismic performance of the elastomeric bearing becomes poor.

유연한 고무재료를 사용하는 탄성받침은 최근 교량의 내진보강용으로 많이 적용되고 있다. 그러나 다양한 요인에 의하여 고무재료의 노화가 진행되고 이로 인해 탄성받침의 전단강성에 변화가 생기고 이는 교량의 내진성능에 영향을 미친다. 천연고무를 대상으로 노화촉진시간과 노출시간을 변수로 하여 노화촉진시험을 수행하여 전단특성의 변화를 분석하였다. 노화가 진행될수록(노화촉진온도 및 노출시간이 증가할수록) 최대전단응력과 전단변형율은 감소한다. 또한 동일한 전단변형률에서 전단강성이 크게 증가한다. 이는 고무재료가 경화됨을 의미하며 탄성받침의 내진성능이 저하되는 것을 암시한다.

Keywords

Acknowledgement

본 연구는 국토교통부 건설기술연구사업의 연구비지원(19SCIP-B146946-03)에 의해 수행되었습니다.

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