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Setting Characteristic Assessment of Cementitious Materials using Piezoelectric Sensor

압전소자를 이용한 시멘트계 재료의 응결 특성 평가

  • Lee, Chang Joon (Department of Architectural Engineering, Chungbuk National University) ;
  • Lee, Jun Cheol (School of Architecture and Civil Engineering, Kyungpook National University) ;
  • Shin, Sung Woo (Department of Safety and Engnieering, Pukyung National University) ;
  • Kim, Wha Jung (School of Architecture and Civil Engineering, Kyungpook National University)
  • Received : 2016.04.12
  • Accepted : 2016.07.20
  • Published : 2016.10.20

Abstract

The evolution of electro-mechanical impedance (EMI) of the piezoelectricity (PZT) sensor was investigated to determine the setting times of cementitious materials in this study. The PZT sensor coated with non-conductive acrylic resin was embedded in cement paste before casting and the EMI signatures were continuously measured. Vicat needle test and semi-adiabatic calorimetry test were also conducted to justify the validity of EMI senssing technique in setting monitoring of cementitious materials. The results show that significant changes in EMI resonant peak magnitude and frequency during setting process were observed, and that the setting times determined by EMI sensing technique were relevant to the setting times measured by Vicat needle test and semi-adiabatic calorimetry test.

본 연구에서는 압전소자의 EMI 신호변화를 이용하여 시멘트계 재료의 응결특성을 평가하였다. 시멘트 페이스트에 매립된 PZT센서의 수화시간에 따른 EMI 신호변화를 비카트침 시험과 간이단열시험을 통한 수화온도곡선과 비교하였다. 실험결과, 시멘트 페이스트가 수화함에 따라 PZT센서의 EMI 공진피크와 공진주파수의 변화가 나타났으며, 이러한 변화시점은 비카트침 시험과 간이단열시험을 통한 수화온도곡선으로부터 획득한 응결시간과 부합하는 것으로 나타났다.

Keywords

References

  1. Annual Book of ASTM Standards. ASTM Test Method for Time of Setting of Hydraulic Cements by Vicat Needle (C 191). West Conshohocken (PA): ASTM International; 2002. 179-84 p.
  2. Annual Book of ASTM Standards. ASTM Test Method for Time of Setting of Concrete Mixtures by Penetration Resistance (C 403/C 403M). West Conshohocken (PA): ASTM International; 2003. 228-33 p.
  3. Christensen BJ. Time of Setting-Significance of Tests and Properties of Concrete and Concrete-Making Materials. West Conshohocken (PA): ASTM International; 2006. 86-97 p.
  4. Shin SW, Qureshi AR, Lee JY, Yun CB. Piezoelectric sensor based nondestructive active monitoring of strength gain in concrete. Smart Materials and Structures. 2008 Jul 18;17(5):1-8.
  5. Wang D, Zhu H. Monitoring of the strength gain of concrete using embedded PZT impedance transducer. Construction and Building Materials. 2011 Sep;25(9):3703-8. https://doi.org/10.1016/j.conbuildmat.2011.04.020
  6. Park GH. Assessing Structural Integrity Using Mechatronic Impedance Transducers with Applications in Extreme Environments [Dissertation]. [Blacksburg (VA)]: Virginia Tech; 2000. 126 p.
  7. Soh CK, Bhalla S. Calibration of piezo-impedance transducers for strength prediction and damage assessment of concrete. Smart Materials and Structures. 2005 Jun 29;14(4):671-84. https://doi.org/10.1088/0964-1726/14/4/026
  8. Gu H, Song G, Dhonde H, Mo YL, Yan S. Concrete early-age strength monitoring using embedded piezoelectric transducers. Smart Materials and Structures. 2006 Nov 2;15(6):1837-45. https://doi.org/10.1088/0964-1726/15/6/038
  9. KS L 5201. Portland cement. Korean Standard Association, Seoul. 2013.
  10. KS L 5109. Testing method for mechanical mixing of hydraulic cement pastes and mortars of plastic consistency. Korean Standard Association, Seoul. 2012.
  11. Mindess S, Young JF, Darwin D. Concrete. 2nd rev. ed. New Jersey: Prentice Hall. 2003. p. 212-3
  12. Neville AM. Properties of concrete. 4th rev. ed. New York: Wiley; 2000. 18 p.