In pretensioned concrete members, a certain distance is required to transfer the prestressing force in strands to the concrete; this is the so-called transfer length, and it is dominated by bond performance between prestressing strands and surrounding concrete. Compared to the normal strength concrete, however, newly developed ultra-high performance concrete (UHPC) shows different bond characteristics of prestressing strands because it has a very dense matrix. Therefore, this experimental study was conducted to investigate the transfer length of prestressing strands in UHPC members, in which the compressive strength of UHPC and volume fraction of steel fiber were considered as the main variables. In addition, by comparing the test results with current code provisions and other models proposed by previous researchers, the applicability for estimation of the transfer length of UHPC members was examined.
프리텐션 콘크리트 부재에서는 긴장재의 프리스트레싱 힘을 콘크리트에 전달하기 위한 특정 길이가 요구되며, 이를 전달길이라고 정의한다. 이러한 전달길이는 긴장재와 콘크리트 사이의 부착성능에 의해 영향을 받는다. 한편 최근 새롭게 개발된 초고성능 콘크리트(UHPC)는 밀실한 매트릭스를 가지고 있기 때문에 일반강도 콘크리트와는 다른 긴장재와의 부착특성을 나타낸다. 따라서, 이 연구에서는 UHPC 부재에서 프리스트레싱 긴장재의 전달길이를 규명하기 위한 실험적 연구를 수행하였으며, 프리스트레스 도입 시 콘크리트 압축강도 및 강섬유 혼입률을 실험변수로 설정하였다. 이와 더불어, 실험결과를 현행 구조기준 및 이전 연구자들의 제안식과 비교함으로써 이들 식이 UHPC 부재의 전달길이 산정에 적용이 가능한지를 파악하고자 하였다.
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- Publisher :Korea Concrete Institute
- Publisher(Ko) :한국콘크리트학회
- Journal Title :Journal of the Korea Concrete Institute
- Journal Title(Ko) :콘크리트학회 논문집
- Volume : 31
- No :1
- Pages :41-48