Impact of Saturation and Frequency of AC Voltage on Impedance and Piezoresistive Response of Self-Sensing Concrete for Structural Health Monitoring (SHM)

Self-sensing concrete (SSC) has emerged as a promising material for Structural Health Monitoring (SHM) due to its ability to detect internal strain and damage through its intrinsic electrical properties. This study investigates the combined influence of saturation and alternating current (AC) frequency on the impedance and piezoresistive behavior of SSC. The specimens were prepared using conductive steel fibers (CSF). Impedance and stress-resistivity measurements were conducted across a range of AC frequencies. Results indicate that drying significantly affects both impedance magnitude and phase angle, with more pronounced effects observed at higher frequencies. Additionally, the piezoresistive response of SSC exhibited strong frequency dependence. These findings highlight the importance of accounting for environmental factors and input in the design and implementation of SSC-based SHM systems. The study provides data analysis for optimizing measurement protocols to enhance the sensitivity and accuracy of self-sensing materials in real applications.