Enhancing Ductile Performance in Bridge Column Rehabilitation Through Advanced Welded Joint Design

Reinforced concrete columns supporting concrete arch bridges often face damage from corrosion and seismic actions. Rehabilitating these damaged columns frequently involves replacing corroded or compromised steel rebars. Welded joints offer a practical solution for connecting new rebar to existing ones, even in cases of irregular reinforcement. However, traditional welding methods have typically overlooked the importance of seam overstrength, resulting in brittle responses and plastic hinge formation in critical locations. To ensure a ductile failure mode, it is crucial to design these joints properly. In real-world rehabilitation scenarios, time and cost constraints necessitate shorter welding seams. Therefore, ensuring adequate seam overstrength becomes paramount. This study investigates effective welding methods for connecting existing and new rebar segments, addressing on-site challenges such as limited space and orientation. The authors propose a methodology for rehabilitating damaged RC columns based on the results of over 100 tensile tests conducted at Fuzhou University in China.