DOI: 10.36347/sjet

Pages: 80-93

This study presents an effort for the damage assessment of reinforcing bars using bonded piezoelectric transducers and the implementation of an integration approach based on the electromechanical admittance method. The damage is the result of excessive elongation of the bar due to yielding caused by flexural deformation of are in forced concrete element or by local steel corrosion and it is simulated considering reduced bar diameter along the damaged part of its length. Test measurements of healthy and artificially damaged steel bars have been conducted using the developed monitoring system. The experimental program comprises data acquisition of current density curves for healthy and damaged bars as detected by the test instrumentation and implementation of the adopted admittance-based procedure to evaluate damages at different levels. Analytical simulations of the same healthy and damaged bars have also been carried out using the finite element software COMSOL. It was found that the sensitivity of the piezoelectric transducers greatly depends on the selection of the excitation frequencies. Current density and admittance curves demonstrated discrepancies between the response of the healthy and the damage states. Admittance signatures showed a clear gradation of the examined damage levels.