Unified Resistivity-Based Framework for Multimechanism Damage Diagnosis and SDG-Aligned Sustainability Assessment in Concrete Structures

Electrical resistivity has proven to be a sensitive nondestructive evaluation (NDE) parameter for capturing both structural and durability-related deterioration in reinforced concrete, including corrosion, cracking, and delamination. This study develops a unified resistivity-based monitoring framework that functions primarily as a diagnostic and interpretative tool, integrating experimental diagnostics, quantitative damage indices, and sustainability-oriented assessment for condition-based management of concrete infrastructure. A conceptual diagnostic curve is formulated to represent characteristic resistivity trends associated with healthy concrete; corrosion-affected zones; compressive, tensile, and flexural cracking; and subsurface delamination, enabling mechanism-specific interpretation of measured values. Two resistivity-derived damage indices (DI) are introduced to normalize deviations from healthy-state benchmarks for both conductivity-increasing (corrosion and cracking) and conductivity-reducing (delamination) deterioration modes, with threshold ranges proposed for healthy, moderately damaged, and critically damaged conditions. The framework is experimentally validated across multiple concrete grades and exposure scenarios, demonstrating that electrical resistivity reliably captures the evolution of internal damage and electrochemical activity relevant to service-life assessment. To place the proposed methodology within a broader sustainability context, a structured Sustainable Development Goals (SDG)-based evaluation framework is used, indicating strong qualitative alignment with resilient infrastructure development, sustainable urban systems, and resource-efficient construction practices under SDG 9, SDG 11, and SDG 12. The proposed framework provides a practical, data-driven basis for early-stage damage diagnosis and informed maintenance decision-making, supporting sustainable life-cycle management of reinforced concrete structures.