Damage Detection of Epoxied Joint Model in Precast Concrete Segmental Bridges Using PZT Technology

Abstract

The feasibility of integrating the wave propagation (WP) method with the electromechanical impedance (EMI) method in damage diagnosis of joints in precast concrete segments under shear load was experimentally studied. The variation of voltage signals, relative voltage attenuation coefficient (RVAC), resistance curves, and RMS deviation (RMSD) index was discussed to investigate the time and location of fracture occurrence. The male–female single-key joint specimens were match cast and connected with epoxy resin adhesive. Voltage signals and resistance of piezoelectric lead zirconate titanate (PZT) transducers were measured at the healthy state and every load interval. The RVAC and RMSD value were presented as quantitative assessments of the damage. The results indicated that as the load increased, the peak value of the voltage signals and resistance curves decreased. The downward shift of the voltage wave and the relative change of the RVAC proved that shear damage occurred at the upper and middle parts of the epoxied single-key joint. Furthermore, the variation of the resistance curves and the RMSD value determined the location and quantitatively assessed the extent of the damage. Data analyzed from the test demonstrated the effectiveness of integrating the WP method with the EMI method in damage detection of single-key joints.