Study on Structural Behavior of Locally Corroded Steel Tubular Columns Filled by Recycled Aggregate Self-Compacting Concrete

This study investigates the structural behavior of concrete-filled steel tubular (CFST) columns under axial compression, focusing on the effects of recycled aggregate concrete (RAC) and varying levels of simulated corrosion. A total of eighteen CFST columns, including short and long specimens, were fabricated using natural and recycled aggregates at 30% and 60% replacement levels. This research is distinctive in its use of simulated regional corrosion to accelerate degradation under controlled conditions, providing novel insights into the performance of CFST columns in corrosive environments. Findings reveal that while RAC can maintain comparable structural efficiency to natural aggregate concrete, higher recycled aggregate content results in slightly reduced load-bearing capacity. Increased corrosion levels further diminish capacity, especially in columns with higher RAC content. Comparative analyses with Eurocode 4 (EC4), Architectural Institute of Japan code, and Chinese code underscore the reliability of EC4 in predicting structural performance with high accuracy. This study advances sustainable construction practices by optimizing RAC usage in CFST columns and provides essential data for enhancing corrosion control measures in structural design.