Reinforced concrete is extensively utilized in construction; however, its durability is compromised by corrosion, particularly chloride-induced corrosion prevalent in coastal areas and cold regions where de-icing salts are applied. Timely assessment and monitoring of corrosion are vital for developing effective mitigation strategies and ensuring structural safety.

This thesis introduces a multiscale analytical framework that integrates macroscopic, microscopic, and nanoscopic perspectives to comprehensively elucidate corrosion-induced bond deterioration in reinforced concrete. At the macroscale, accelerated corrosion techniques combined with uniaxial tensile tests on reinforced concrete tie specimens were employed. Distributed fiber optic sensing embedded within the rebar, supplemented by digital image correlation and photogrammetry, facilitated the acquisition of critical data, including mass loss of rebar, surface cracking patterns of concrete, strain distribution, bond stress and slip. Microscale analyses utilized X-ray diffraction, scanning electron microscopy, and nanoindentation to elucidate composition, morphology, and mechanical properties of corrosion products and cement hydrates. At the nanoscale, molecular dynamics simulations provide insights into the physicochemical evolution of corrosion products and their interactions with cement hydrates.

Macroscopic preliminary experiments revealed that corrosion may significantly alter strain distribution and bond characteristics, with distributed fiber optic sensor successfully capturing these changes. Molecular dynamics simulations highlighted that mechanical models at the nanoscale lack accuracy for multiscale studies; thus, improvements were made in data extraction methods, size effect considerations, and strain representation. The refined mechanical models are more suitable for multiscale research. To conclude the current research findings, this study has demonstrated the feasibility of multiscale research on corrosion-induced bond deterioration.

The integration of these multiscale analyses validates the hypothesis that a comprehensive cross-scale approach can effectively elucidate corrosion-induced bond deterioration in reinforced concrete. This framework not only bridges the gap between structural and material perspectives but also provides a robust foundation for future research and the development of targeted anti-corrosion strategies for critical bond members.