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Measurement of Transfer Length for a Seven-Wire Strand with FBG Sensors

FBG 센서를 이용한 강연선 전달길이 측정

  • Lee, Seong-Cheol (Department of NPP Engineering, KEPCO International Nuclear Graduate School) ;
  • Choi, Song-Yi (Department of Marine and Civil Engineering, Chonnam National Univ.) ;
  • Shin, Kyung-Joon (Department of Civil Engineering, Chungnam National Univ.) ;
  • Kim, Jae-Min (Department of Marine and Civil Engineering, Chonnam National Univ.) ;
  • Lee, Hwan-Woo (Department of Civil Engineering, Pukyung National Univ.)
  • 이성철 (국제원자력대학원대학교 원자력산업학과) ;
  • 최송이 (전남대학교 해양토목공학과) ;
  • 신경준 (충남대학교 토목공학과) ;
  • 김재민 (전남대학교 해양토목공학과) ;
  • 이환우 (부경대학교 토목공학과)
  • Received : 2015.10.26
  • Accepted : 2015.11.25
  • Published : 2015.12.29

Abstract

In this paper, an experimental program has been conducted to investigate transfer length in high strength concrete members pretensioned through a seven-wire strand with FBG sensors. To measure transfer length, five members were fabricated, which had a length of 3 m and a cross-section of $150{\times}150mm$. It was measured that the concrete compressive strength was 58MPa at pretensioning. Test results indicated that more precise and reliable measurement on the transfer length was attained with FBG sensors than conventional gauges attached on concrete surface. Through comparing the measured transfer length and predictions, applicability of several transfer length models in literature was investigated. This paper can be useful for relevant research field such as investigation on the bond mechanism of a seven-wire strand in concrete members.

본 논문에서는 프리텐션된 고강도 콘크리트 부재에서의 전달길이를 측정하기 위해 FBG 센서가 기입된 스마트 강연선을 활용하여 실험을 수행하였다. 전달길이 측정을 위해 길이 3m, 단면 $150{\times}150mm$의 고강도 콘크리트 시험체를 총 5개 제작하였으며, 프리텐션 도입 시 콘크리트 압축강도는 58MPa로 측정되었다. 실험 결과 콘크리트 표면에 부착하는 기존의 전기 저항식 게이지보다 FBG 센서로부터 보다 정밀하고 신뢰성있는 강연선의 전달길이를 계측할 수 있는 것으로 나타났다. 계측결과로부터 산정된 강연선 전달길이를 기존의 여러 모델들과 비교하였으며, 이를 통해 고강도 콘크리트 부재에서의 전달길이 산정에 대한 기존 모델들의 적용성을 분석하였다. 본 연구 내용은 향후 강연선의 부착 특성 분석 등의 관련 분야 연구 등에 유용할 것으로 기대된다.

Keywords

References

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