Early-age behavior of the concrete strongly influences structural properties, yet most conventional methods are destructive and discontinuous. This study presents a real-time monitoring of setting time, hydration, strength development, and stiffness evolution in concrete incorporating Ordinary Portland Cement (OPC), Portland Pozzolana Cement (PPC), and Fiber-Reinforced Concrete using an embedded smart piezoelectric (PZT) patch sensor. The work provides an application-based comparison of electromechanical interference EMI-PZT performance and evaluates the correlation between the compressive strength and real-time stiffness evolution throughout 28 days. Experimental results revealed that OPC exhibited the highest peak temperature (38°C) and heat liberation (137J), followed by PPC (33°C; 122 J) and FRC (31°C; 115 J), reflecting variations in hydration kinetics. At 28 days, OPC achieved a stiffness of 112 kNs/m which was 21% higher than PPC (88 kNs/m) and 12% higher than FRC (98 kNs/m). OPC also attained the highest compressive strength of 41 MPa, exceeding PPC and FRC concretes by 21% and 12%, respectively. A 30% increase in stiffness relates to a 65% increase in compressive strength, confirming a direct relationship between stiffness and the strength development of concrete. Overall, the study validates EMI-PZT sensing as an effective, real-time, nondestructive technique for evaluating concrete hydration.
Kishore et al. (Tue,) studied this question.