Structural Health Monitoring of Reinforced Concrete Beam-Column Joints Using Piezoelectric Transducers

Traditional methods for estimating structural deterioration are generally costly and inefficient, especially for non-accessible structural members. However, recent research has demonstrated that electro-mechanical impedance (EMI) or its inverse electro-mechanical admittance (EMA) measurements can be used to continuously monitor the structural integrity of reinforced concrete (RC) civil infrastructures in real-time. In this work, three lead piezoelectric zirconate titanate (PZT) transducers were epoxy-bonded on the external surface of a real-scale RC beam-column joint (BCJ) specimen. An integrated wireless impedance/admittance monitoring system (WiAMS) excites and simultaneously measures the voltage signal response of the PZT transducers in various imminent damage states. Furthermore, a scalar statistical index is employed to quantify the structural damage based on the variation of the PZT output voltage signals between their response at different damage levels and a pristine, undamaged state (initial healthy). The results of this study indicate that through the EMI technique, external epoxy-bonded PZT transducers can reliably evaluate the structural integrity of BCJs.