Bond behavior of steel bars in ECC-GFRP spirals confined concrete subjected to accelerated chloride corrosion coupled with sustained loads

This study investigates the bond behavior of steel bars embedded in engineered cementitious composite (ECC) structures reinforced with glass fiber-reinforced polymer (GFRP) spirals, as compared to conventional reinforced concrete (RC) under sustained loading and accelerated corrosion conditions. The ECC-GFRP confinement system demonstrated substantial advantages in bond strength , durability, and corrosion resistance . Experimental findings revealed that ECC specimens maintained complete bond-slip curves and higher peak and residual bond strengths, even under harsh conditions, owing to the system’s enhanced crack control and prevention of corrosive media intrusion. In contrast, RC specimens exhibited brittle failure modes and a sharp decline in bond strength after reaching peak stress, attributed to cracking in the concrete cover. Corrosion-induced expansion in both specimen types initially increased bond strength due to elevated interfacial stresses, but sustained loading was found to accelerate microcrack formation, facilitating corrosion ingress in RC specimens particularly. These results highlight the potential of the ECC-GFRP confinement system to extend structural service life by providing superior bond performance and durability in corrosive environments , supporting its use in high-demand applications where combined mechanical and environmental stresses are present. • ECC-GFRP confinement significantly enhances bond strength and durability under corrosion. • RC specimens exhibit brittle failure modes with sharp bond strength reduction under stress. • Sustained load accelerates microcrack formation, increasing corrosion in RC specimens. • ECC-GFRP system effectively restricts corrosion ingress, maintaining long-term bond integrity.