Numerical simulation of tubular piezoceramics-based smart aggregate embedded in asphalt mixture for health monitoring.

Health monitoring plays an important role in the maintenance of asphalt pavement. Tubular smart aggregate (TSA) is a cylindrical sensor composed of lead zirconate titanate (PZT) and protective coating. Ultrasonic waves are produced when the TSA vibrates and can be used to monitor the health of asphalt pavement. The influence of the protective coating material of the TSA, elastic modulus of PZT, and diameter of the TSA on the TSA resonant frequency was studied. A voltage signal and mechanical load were applied to the TSA; vibration and the received voltage of the TSA were collected. Furthermore, two TSAs were embedded in an asphalt mixture to transmit and receive ultrasonic waves. The vibration and generated voltage by the TSA embedded in the asphalt mixture were collected. Results indicate that the resonant frequency of the TSA increases with the increase of the elastic modulus of protective coating and PZT. With the increase of the diameter of the TSA, the resonant frequency of the TSA decreases gradually. When the voltage signal and mechanical load subjected to the TSA were close to the resonant frequency of the TSA, larger vibration and voltage were generated. Due to the viscoelasticity of the asphalt mixture, the resonant frequency of the TSA embedded in an asphalt mixture was reduced. [ABSTRACT FROM AUTHOR]