Embedded PZT sensors for monitoring formation and crack opening in concrete structures

An application for sensing the stress-induced localization of damage in the form of a discrete crack in a concrete substrate is developed using embedded PZT patches. Stress-wave measurements are obtained through the stages of damage localization leading to crack formation, propagation, and opening of the discrete, localized crack in the concrete. A self-compensating attenuation factor is proposed to quantify the changes in stress waves produced by the material discontinuity introduced by cracking in concrete. The attenuation factor measurements provide a sensitive indication of displacement discontinuity introduced by a crack in the stress wave path. Displacement discontinuity in concrete associated with a crack opening smaller than 10 μm in the loaded state is detected in the attenuation factor measurements even after the removal of stress. The embedded PZT sensors can continuously monitor concrete structures for indications of crack formation before visual indication. © 2021 Elsevier Lt