Corrosion-induced changes in the serviceability behavior of reinforced concrete beams under cyclic loading

Artikel i vetenskaplig tidskrift, 2026

Understanding the development of reinforcement corrosion and its effects on the service life of reinforced concrete (RC) structures remains a critical challenge, accompanied by significant uncertainties. Corrosion is one of the most prevalent deterioration mechanisms in RC infrastructure, leading to reduced structural performance, increased maintenance costs, and serious safety concerns. Previous studies have investigated the influence of corrosion on the structural response of RC members, while distributed optical fiber sensing (DOFS) has emerged as a promising technique for monitoring strains, cracking, and deflection in RC structures. Earlier research has also demonstrated the potential of DOFS-based deflection measurements for characterizing localized corrosion propagation. However, the applicability of such approaches under varying reinforcement configurations and corrosion conditions remains insufficiently understood. In this study, the serviceability response of RC beams subjected to cyclic loading and accelerated corrosion was investigated using DOFS measurements. A previously developed framework for describing corrosion propagation based on corrosion-induced deflections was validated and extended to different reinforcement diameters, bar arrangements, and corroded regions. The results showed that the framework became less accurate when corrosion was more uniformly distributed rather than localized in pits. Furthermore, a detailed analysis of the strain evolution at a representative cracked section revealed that corrosion-induced non-mechanical strains propagated throughout the cross-section until longitudinal cracking occurred. Subsequently, an apparent Young's modulus derived from sectional strain distributions proved to be a useful indicator of corrosion progression.