한국지반환경공학회 논문집 (Journal of the Korean GEO-environmental Society)

  • 제17권3호
  • /
  • Pages.13-19
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  • 2016
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  • 1598-0820(pISSN)
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  • 2714-1233(eISSN)
한국지반환경공학회 (Korean Geo-Environmental Society)
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양생시간에 따른 유동성 채움재의 전단파 특성

Characteristics of Shear Waves in Controlled Low Strength Material with Curing Time

  • Han, Woojin (School of Civil, Environmental and Architectural Engineering, Korea University) ;
  • Lee, Jong-Sub (School of Civil, Environmental and Architectural Engineering, Korea University) ;
  • Byun, Yong-Hoon (Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign) ;
  • Cho, Samdeok (KOREA INSTITUTE of CIVIL ENGINEERING and BUILDING TECHNOLOGY) ;
  • Kim, Juhyong (KOREA INSTITUTE of CIVIL ENGINEERING and BUILDING TECHNOLOGY)
  • 투고 : 2015.10.20
  • 심사 : 2016.02.03
  • 발행 : 2016.03.01
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초록

기존의 콘크리트 조기강도의 발현 및 응결특성을 파악하기 위하여 탄성파 기법을 이용한 콘크리트의 모니터링에 대한 많은 연구가 수행되어 왔다. 본 연구에서는 저강도 콘크리트의 일종인 유동성 채움재(CLSM)에 대한 응결특성을 파악하기 위하여 전단파 트랜스듀서인 벤더 엘리먼트를 활용하였으며, 양생시간에 따른 CLSM의 전단파 특성을 조사하였다. 조기강도 및 유동성을 확보하기 위하여 CLSM은 CSA계 시멘트, 비회, 실트 및 모래, 급결제, 물로 구성되었으며 세립분 함량에 따른 전단파 특성 변화를 보기 위해 3종류의 CLSM 시료를 배합하였다. 전단파 측정을 위한 셀은 셀 벽면에 한 쌍의 벤더 엘리먼트가 설치되었고, 배합된 CLSM 시료를 전단파 측정용 셀에 조성하여 양생시작부터 28일간 전단파 변화를 모니터링 하였다. 실험결과 CLSM의 세립분 함량에 상관없이 양생시간이 증가함에 따라 전단파의 공진주파수 및 속도는 증가하였다. 또한, 양생시작부터 약 10시간까지는 전단파의 진폭도 증가하였으며, 동일한 시각에서는 세립분 함량이 적을수록 공진주파수 및 속도가 크게 나타났다. 본 논문에서 제안된 벤더 엘리먼트를 이용한 전단파 측정기법은 양생기간에 따른 CLSM의 응결특성을 평가하는 데 유용하게 사용될 수 있을 것으로 판단된다.

The ultrasonic waves for monitoring concrete materials have been used to investigate the setting and hardening process of concrete. This paper presents the application of bender elements for monitoring the hardening properties of Controlled Low Strength Material (CLSM) and the characterization of shear waves in CLSM according to curing time. To ensure the early age properties and flow, the CLSM consists of CSA cement, sand, silt, water, fly ash, and accelerator. In addition, three different type specimens according to fine contents are mixed. A couple of bender elements are installed at the wall of measurement cell and the CLSM specimen are prepared at the measurement cell for 28 days. Experimental results show that the resonant frequency and shear wave velocities increase with an increase in the curing time, regardless of the fine contents. Up to ten hours, the amplitudes of shear waves also increase, and the resonant frequency and shear wave velocities at the same time increase as the fine contents increase. The shear wave measurement technique using the bender elements may be effectively used to evaluate the hardening properties of CLSM along the curing time.

키워드

참고문헌

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피인용 문헌

  1. Effect of Fly Ash on Strength and Stiffness Characteristics of Controlled Low-Strength Material in Shear Wave Monitoring vol.14, pp.11, 2021, https://doi.org/10.3390/ma14113022
  2. Evaluation of engineering properties of expandable foam grout with admixture content vol.293, pp.None, 2021, https://doi.org/10.1016/j.conbuildmat.2021.123488