Monitoring hydration of concrete using EMI of surface bonded smart piezo patches

Smart materials possessing piezoelectric characteristics are nowadays utilized by researchers as an emerging material for monitoring health of the structures. As concrete one of mostly used building material, its real-time prognosis from its plastic states to the hardened states and even to its complete life span, is become easier, economical and time-saving while utilizing lead zirconate titanate (PZT) patches and Electro-mechanical impedance (EMI) technique. In this paper, a numerical study has been demonstrated for assessing concrete health at different days of its hydration states, after developing and analyzing the finite element (FE) models of concrete cube of 150 mm × 150 mm × 150 mm with adhesively bonded PZT patch on its surface. High frequency excitations were imposed to PZT patch to capture the EMI response of the substrate in form of conductance and susceptance signatures. The development in strength or say its health gain with modified substrate characteristics upon hydration is quantified statistically in term of root mean square deviation (RMSD) index. The validation of experimental outputs from literature has been carried out with a high accuracy, followed with demonstrating the parametric study to judge the EMI signatures variation with changing properties of the concrete substrate on hydration. The mathematical regression models are also proposed for relating the RMSD variations with concrete properties. The PZT patch enabled EMI outputs for developed FE model founds satisfactory in providing higher performance for real-time monitoring problems that will be helpful for engineers and researchers for estimating concrete hydration at any instance in its life span.