Journal of the Korean Recycled Construction Resources Institute (한국건설순환자원학회논문집)

Korean Recycled Construction Resources Institute (한국건설순환자원학회)
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Estimation Error and Reliability of Measuring Unit Water Content Test Methods for Fresh Concrete Depending on Mix Design Factors at the Laboratory Level

실험실 수준에서 배합변수별 굳지 않은 콘크리트 단위수량 실험방법의 추정오차 및 신뢰성 검토

  • Park, Min-Yong (Department of Architectural Engineering, Cheong-ju University) ;
  • Han, Min-Cheol (Department of Architectural Engineering, Cheong-ju University)
  • 박민용 (청주대학교 건축공학과) ;
  • 한민철 (청주대학교 건축공학과)
  • Received : 2022.03.02
  • Accepted : 2022.03.29
  • Published : 2022.03.30
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Abstract

In this study, water content tests were performed on various fresh concretes subjected to different binder compostions to review the estimation errors and reliability of water content test methods. Micro-oven drying method, air-meter method, capacitance method and microwave penetration method were used to estimate water content of fresh concrete. Errors in water content estimation were analyzed by each test method. Regardless of the test method of water content, the estimation error was less than 5 %, and in the case of the test using mortar, the error in the estimation value was relatively large. In addition, based on the test results of water content of various concrete, the probability density function in which the estimation error for each test method becomes the population was analyzed. Water content test methods of fresh concrete which using concrete samples showed high estimate reliability of 97 % within the estimation error range of ± 10 kg/m3. On the other hand, the reliability of water content test method using mortar samples was lower.

본 연구에서는 고주파가열법, 단위용적질량법, 정전용량법 및 마이크로파법의 4가지의 굳지 않은 콘크리트의 단위수량 시험방법의 신뢰성을 검토하기 위해 배합요인, 혼화재 치환율 및 골재의 물리적 특성 변화에 따른 다양한 콘크리트를 대상으로 단위수량 실험을 실시하고 시험방법별 단위수량 추정값의 오차를 분석하였다. 단위수량의 시험방법과 무관하게 추정오차는 5 % 이하의 수준을 나타냈으며, 모르타르를 이용하는 시험의 경우 상대적으로 추정값의 오차가 크게 나타났다. 다양한 배합의 콘크리트에 대한 단위수량 실험결과를 토대로 각 실험방법별 추정오차를 모집단으로 하는 확률밀도함수를 분석한 결과 모르타르 시료를 이용하는 단위수량 실험방법은 추정오차 ± 15 kg/m3 내 97 %, 콘크리트 시료를 이용하는 단위수량 실험방법은 추정오차 ± 10 kg/m3 내 97 % 이상의 신뢰성을 나타냈다. 향후 실제현장에서 다양한 생산변수를 고려하여 단위수량 실험방법의 신뢰성을 추가적으로 검증할 수 있는 연구가 필요할 것으로 판단된다.

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