Effects of seawater corrosion on compression-induced buckling performance of FRP-CFST columns

This study experimentally investigated axial compression-induced buckling performances of FRP confined concrete filled steel tube (FRP-CFST) columns after exposure to seawater corrosion environment. Sixty-three stub FRP-CFST are manufactured, and sixty of them were exposed to three simulated seawater corrosion conditions with 120, 240, 360 days. Four-stage failure mode of the axial compression-induced buckling tests was observed and analyzed. Comparative analysis indicated that FRP-CFST can effectively resist normal seawater corrosion, while weaker durability is observed from columns in triple-salinity seawater environments, particularly with wet-dry cycles conditions. Under the same corrosion conditions, CFST columns wrapped with Carbon Fiber reinforced polymer (CFRP) exhibited preferable buckling resistance performance than those with Basalt Fiber reinforced polymer (BFRP). Based on mechanism analysis of the axial compression-induced buckling tests, a theoretical evaluate model for compression-induced buckling performances of FRP-CFST after seawater corrosion is proposed and verified. The outcomes of this research can provide experimental and theoretical basis for evaluating the durability of FRP-CFST under seawater corrosion environment.