In earthquake-prone regions, the structural integrity and seismic performance of buildings are critical for ensuring safety and resilience. Among various structural systems, composite steel-concrete columns have gained significant attention due to their ability to combine the advantages of both steel and concrete materials. These columns typically consist of a steel section encased in or filled with concrete, leading to enhanced strength, stiffness, and ductility compared to traditional reinforced concrete or steel-only columns.

However, under severe seismic loading, composite columns can still experience damage, including cracking of concrete, buckling of steel elements, and deterioration of the bond at the steel-concrete interface. To further improve their seismic resistance, Carbon Fiber Reinforced Polymer (CFRP) wraps or laminates are increasingly being investigated and applied as an advanced reinforcement technique.

CFRP materials are lightweight, corrosion-resistant, and exhibit high tensile strength, making them ideal for retrofit and strengthening applications. When applied to composite columns, CFRP can:

• Improve confinement of concrete, thereby increasing its compressive strength and ductility.

• Delay or prevent local buckling of steel sections.

• Enhance the energy dissipation capacity and post-yield behavior of the column under cyclic loading.

• Mitigate spalling of concrete and maintain the column’s integrity during strong ground motion.

Recent experimental and numerical studies have shown that CFRP-reinforced composite columns exhibit improved seismic performance, including higher lateral load capacity, reduced residual deformations, and better hysteretic behavior. The effectiveness of CFRP reinforcement depends on several factors, such as the type of composite section (e.g., concrete-filled steel tube vs. steel-reinforced concrete), amount and orientation of CFRP wraps, and the quality of the bond between CFRP and the substrate.

This area of research remains dynamic, with ongoing studies aimed at optimizing CFRP application techniques, developing analytical models for predicting seismic response, and establishing design guidelines to integrate CFRP reinforcement into seismic retrofitting strategies for composite structures.

The present example is similar to this paper:” Experimental research and finite element analysis on seismic behavior of CFRP-strengthened seismic-damaged composite steel-concrete frame columns .”