Chloride-induced degradation in blended concrete systems: A comparative study under ideal and combined exposure conditions using embedded piezo sensors

Concrete structures in marine and coastal regions frequently degrade due to chloride exposure and service loads, leading to complex interactions that complicate structural health assessment. Most research has focused on evaluating the durability of these structures under ideal conditions, primarily considering chloride exposure and using conventional techniques. However, studies addressing the combined effects of service loads and chloride exposure remain limited. This study aims to non-destructively assess degradation under both ideal and combined conditions using embedded piezo sensors (EPS). Three types of concrete systems—Portland pozzolana cement (PPC-C), Portland pozzolana with a concrete enhancer (PC-C), and Portland pozzolana with both a concrete enhancer and slag (PSC-C)—are embedded with EPS and subjected to ideal and combined exposure for 90 days. The conductance signature changes acquired by EPS through the electro-mechanical impedance (EMI) technique are analyzed to extract equivalent structural parameters. The results indicate that PSC-C demonstrated the best performance under both ideal and combined exposure conditions, followed by PC-C and PPC-C. These findings confirm that EPS is an effective sensor for detecting physicochemical and mechanical changes in various concrete systems and identifying degradation. Furthermore, the study underscores the importance of optimized mix designs in significantly enhancing concrete durability.