Journal of the Korea Institute of Building Construction (한국건축시공학회지)

The Korean Institute of Building Construction (한국건축시공학회)
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Effect of Size Factor on Estimating Elastic Modulus of Disk-Shaped Concrete Specimen Using Impact Resonance Test

충격공진법을 이용한 콘크리트 원판 시편의 탄성계수 추정에 크기 인자가 미치는 영향

  • Kim, Min-Suk (Graduate School, Chungbuk National University) ;
  • Son, Joeng Jin (Graduate School, Pukyong National University) ;
  • Lee, Chang Joon (Department of Architectural Engineering, Chungbuk National University) ;
  • Chung, Chul-Woo (Department of Architectural Engineering, Pukyong National University)
  • Received : 2022.11.07
  • Accepted : 2022.12.14
  • Published : 2023.02.20
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Abstract

In this work, a depth-by-depth evaluation on the deterioration of concrete is suggested by utilizing disk shaped concrete specimens. Dynamic elastic modulus of cylindrical concrete was measured using a free-free resonance column method and compared with dynamic elastic modulus of disk-shaped concrete measured by impulse excitation technique(IET) and impact resonance(IR). According to the results of the experiment, both IET and IR methods showed a smaller difference in dynamic elastic modulus with smaller deviation in data when thickness of the disk specimen was increased. This trend was more evident from dynamic elastic modulus measured by IR method compared to that measured by IET. Variation in data was also smaller with the IR result. To increase the accuracy of the data, it is recommended to use the IR method for disk specimen with a diameter of 100mm and a thickness of 25mm.

본 연구에서는 디스크형 공시체를 활용하여 콘크리트의 깊이별 열화도를 평가하기 위한 방법을 개발하고자 하였다. 이를 위해 원통형 콘크리트 시편의 동탄성계수는 양단자유공진주기법을, 디스크형 콘크리트 시편의 동탄성계수는 임펄스 기법과 충격공진기법을 활용하여 측정하였고, 이를 비교 분석하였다. 실험결과, 임펄스 기법 및 충격공진기법 모두 동일한 지름일 경우 두께가 두꺼워지면 디스크 시편의 동탄성계수는 원주형 공시체의 동탄성계수에 가깝게 측정되었으며, 그 값의 변동성 은 줄어들었다. 또한 같은 (두께)/(반지름) 비율일 경우 지름이 증가하면 디스크 시편의 동탄성계수 측정값의 변동성은 감소하였고, 이러한 경향은 충격공진기법을 이용한 측정에서 더욱 분명하게 나타났다. 디스크의 동탄성계수 측정 시 지름 100mm, 두께25mm의 시편에 대해 충격공진기법을 이용하는 것이 오차율을 줄일 수 있는 방법으로 확인되었다.

Keywords

Acknowledgement

This work was supported by the Energy R&D Program of the Korea Institute of Energy Technology Evaluation and Planning(KETEP) granted financial resource from the Ministry of Trade, Industry & Energy, Republic of Korea (No.20217910100100).

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