Structural performance of corroded reinforced concrete columns repaired with Textile-Reinforced Mortar (TRM) and corrosion inhibitors

Reinforcement corrosion is a critical durability issue in concrete structures, requiring effective repair methods. This study investigated the use of textile-reinforced mortar (TRM) for repairing corroded small-scale reinforced concrete (RC) columns subjected to axial compression. The TRM systems consisted of carbon fibres and two different mortar matrices, each uniquely modified with distinct organic corrosion inhibitors—a novel approach aimed at enhancing the corrosion resistance and performance of the repair materials. The key parameters investigated included the type of mortar matrix in TRM, the corrosion ratio of steel reinforcements, and exposure to chloride dry-wet cycles. Additionally, half-cell potential measurements were performed on selected specimens to monitor subsequent corrosion after the TRM repair. The test results indicated that TRM confinement effectively improved the compressive strength of the specimens, with strength increments of up to 15% observed across both combinations of mortar matrices and carbon fibres at a corrosion ratio of 10%. However, the effectiveness of the TRM repair decreased slightly, achieving a strength increment of 13% at a higher reinforcement corrosion ratio of 30%. The half-cell potential measurements on TRM-repaired specimens exposed to 300 chloride dry-wet cycles indicated that mortar matrices modified with corrosion inhibitors in the TRM systems were effective in reducing further corrosion and withstanding severe chloride environments. Furthermore, despite exposure to chloride dry-wet cycles, the reduction in TRM effectiveness was minimal, suggesting that corrosion inhibitors contribute to maintaining bonding properties and structural integrity under harsh conditions.