Preliminary Study on the Seismic Behavior of CFRP-Confined Non-Conforming RC Columns with Retained Plaster Layer

Fibre-reinforced polymer (FRP) composites effectively enhance the seismic performance of substandard reinforced concrete (RC) columns through external jacketing. However, conventional FRP retrofitting (external jacketing) requires removal of existing plaster layer over the column surface, increasing costs, labour and disturbance. This study investigates the feasibility of applying external FRP jacket directly over existing plaster. As a preliminary study, three full-scale RC columns were tested under cyclic lateral loads and a constant axial load. Results indicate that direct FRP application over plaster improves both ductility and lateral load capacity remarkably, demonstrating potential of external FRP jacketing of RC columns without removal of plaster layer for reducing retrofitting costs and environmental impact.