Piezoelectric cement sensor and impedance analysis for concrete health monitoring

Abstract

Listen

Translate article

Piezoelectric cement, instead of PZT (lead zirconate titanate) sensors and smart aggregate, has been developed as a new piezoelectric sensor that particularly applies to monitor concrete structures. Piezoelectric cement is a 0-3 type cementbased piezoelectric composite with 50% PZT for improving the incompatibility of acoustic impedance and volume deformation between conventional piezoelectric sensors and concrete structure. Piezoelectric cement was installed in concrete to monitor the strength development with the age and to detect the damage of concrete by electromechanical impedance technique. The PZT sensor was the counterpart in the experiments. Results indicate that, similar to PZT sensors, piezoelectric cement exhibits the capability of monitoring concrete structures, and the sensitivity of monitoring for piezoelectric cement even better than for the PZT if the piezoelectric cement with suitable piezoelectric strain factor d33. Piezoelectric cement embedded in concrete structures show no resonant frequency in the conductance-frequency spectra that causes to assess the conductance change easily. For the piezoelectric cement with d33 = 101 pC/N, the intervals of frequency are 300–660 kHz and 1000–2000 kHz for the strength monitoring and the damage detection, respectively. Broad effective frequency range provides larger RMSD value of conductance.