Heating-time effect on electromechanical admittance of surface-bonded PZT sensor for concrete structural monitoring

Abstract

This paper carried out numerical and experimental investigations to interpret the heating-time effect on the monitoring of concrete structures using surface-bonded piezoelectric (PZT) sensor. In the numerical study, a novel 3D finite element model of layered concrete cube mounted with PZT patch was generated for analysis of thermal hysteresis effect. In the experimental study, equal-sized concrete cube was casted and continuously heated by 180 mins for electromechanical admittance (EMA) measurements. Phase angle/magnitude in the EMA spectra and its baseline-unvaried and -varied root mean square deviation (RMSD/RMSDk) indices were incorporated to quantify the heating-time effect. Results demonstrated that EMA signatures exhibited dual dependences to both temperature regime and heating time, which adversely inflicted an amplified influence on structural damage detection results as well. The findings promoted the inclusion of time factor when evaluating temperature influence on PZT-based concrete structural monitoring.