Characterization of cement-based materials using a reusable piezoelectric impedance-based sensor

Abstract

This paper proposes a reusable sensor, which employs a piezoceramic (PZT) plate as an active sensing transducer, for non-destructive monitoring of cement-based materials based on the electromechanical impedance (EMI) sensing technique. The advantage of the sensor design is that the PZT can be easily removed from the set-up and re-used for repetitive tests. The applicability of the sensor was demonstrated for monitoring of the setting of cement mortar. EMI measurements were performed using an impedance analyzer and the transformation of the specimen from the plastic to solid state was monitored by automatically measuring the changes in the PZT conductance spectra with respect to curing time using the root mean square deviation (RMSD) algorithm. In another experiment, drying-induced moisture loss of a hardened mortar specimen at saturated surface dry (SSD) condition was measured, and monitored using the reusable sensor to establish a correlation between the RMSD values and moisture loss rate. The reusable sensor was also demonstrated for detecting progressive damages imparted on a mortar specimen attached with the sensor under several loading levels before allowing it to load to failure. Overall, the reusable sensor is an effective and efficient monitoring device that could possibly be used for field application in characterization of cement-based materials.

A novel electromechanical impedance–based model for strength development monitoring of cementitious materials

“…In the EMI technique, a PZT transducer is usually surface-bonded on or embedded in concrete structures. 29,30 The PZT transducer acts as collocated actuator and sensor. When a sinusoidal varying voltage is applied to the PZT patch, the PZT vibrates and thus excites the concrete structure through the strain transfer across the bonding layer.…”

“…Further improvements to the EMI-based monitoring techniques have been made by some researchers who have investigated the feasibility of applying reusable PZT transducers on concrete strength monitoring. 27–29 Tawie and Lee 29 proposed a novel reusable PZT sensor, comprising a PZT patch attached on a bolt. The sensor is installed on the rod embedded in the cement mortar and can be taken off for reuse after measuring the EMI.…”

Reusable piezoelectric transducer for structural health monitoring using both Lamb wave and electromechanical impedance modes

“…The PZT was bonded on a metal enclosure which was embedded in the fresh concrete and removed from structure after curing. Tawie and Lee (2011) improved Yang’s method and introduced a novel design of a reusable EMI-based PZT sensor with different rods and employed PZT as an actuator and a sensor in the same time. Na et al (2012) proposed a reusable PZT device to monitor the fiber-reinforced plastic adhesive joints in a corrosive environment by employing the EMI method.…”

Nano graphite platelets-enabled piezoresistive cementitious composites for structural health monitoring

“…Short carbon fiber [1] was firstly introduced into cementitious composites to function as a smart sensing device and allow non-destructive electrical probing of flaws. Recent researches on the conductive cementitious composites mainly focus on adding new types of conductive fillers [2][3][4][5] (e.g. nickel powder [6] and carbon nanotube/nanofiber [7][8][9][10][11][12][13][14][15][16][17]) into the cementitious materials to further modify the sensitivity and stability of the piezoresistive effect.…”