Passive confinement scenarios for strengthening fire-damaged concrete columns: Experimental and analytical research

Abstract

The rehabilitation of fire-damaged concrete structures often presents a challenge, leading to costly demolition and reconstruction. This study explores the potential of fiber-reinforced polymer (FRP) passive confinement systems, specifically full, partial, and hybrid configurations, as effective solutions for restoring the compressive strength of heat-damaged concrete columns. Experimental axial compression tests revealed that hybrid systems, combining glass FRP (GFRP) full jackets with carbon FRP (CFRP) strips, offer a proper balance of cost-effectiveness and confinement efficiency. A unified strength model was developed, applicable to both hybrid and non-hybrid scenarios, and calibrated using an extensive dataset, including 2137 test results. The proposed model demonstrated superior predictive accuracy compared to existing formulations, providing a reliable framework for the design and assessment of FRP-confinement solutions in post-fire applications.