Corrosion Assessment in Steel Reinforcement Using Piezoelectric Sensor for Service Life Prognosis of Reinforced Concrete Structures

The deterioration of reinforced concrete (RC) structures due to the corrosion of steel reinforcement poses significant challenges to structural integrity and service life. This study investigates the application of electromechanical impedance (EMI) techniques using piezoelectric sensors for the real-time assessment of corrosion-induced damage and the prognosis of remaining service life in RC structures. By leveraging the sensitivity of EMI-based methods, this research aims to develop predictive models for quantifying corrosion severity and structural deterioration without direct physical measurements of corrosion parameters. The study examines chloride-induced and carbonation-induced corrosion mechanisms, emphasizing their impact on reinforcement integrity. The EMI technique is employed to monitor corrosion progression by analysing variations in mechanical impedance, which serves as a reliable indicator of structural degradation. Structural parameters such as stiffness and mass loss are extracted from impedance signatures to establish predictive models for corrosion assessment. The stiffness-based model enables phase-wise classification of corrosion progression, while the mass loss model facilitates the estimation of corrosion rates and corresponding reductions in rebar cross-section and structural load-carrying capacity. Experimental validation is conducted using RC specimens subjected to accelerated corrosion conditions, demonstrating the efficacy of EMI-based techniques in accurately assessing corrosion severity. The results establish a strong correlation between impedance-derived parameters and actual structural deterioration, enabling reliable service life estimation. By providing a non-destructive, real-time monitoring framework, the proposed approach offers a viable alternative to conventional electrochemical methods, facilitating proactive maintenance and extending the service life of RC structures. This research underscores the potential of EMI-based structural health monitoring for advancing corrosion assessment methodologies, offering a cost-effective and efficient solution for ensuring the long-term durability of RC infrastructure.