Experimental Study on Seismic Performance of CFRP-Strengthened Recycled Concrete Columns with Different Levels of Seismic Damage

To study the strengthening effect of carbon fiber composite materials (CFRP) on recycled concrete columns subjected to different levels seismic damage, four column specimens were designed for pseudo-static tests. The categorized as non-destructive without (prototype), strengthening, medium damage and severe based replacement rate aggregates level damage. characteristics deformation performance indicators each specimen compared analyzed. results verified OpenSees platform. A decrease was observed in initial stiffness seismically damaged strengthened with CFRP, while ductility, peak bearing capacity, energy dissipation capacity improved. In addition, reduction ductility enhanced degrees. particular, cumulative exposed increased most significantly, by 32.5%. general, hysteretic curves full, average coefficients 4.1–6.8. CFRP more effective restoring enhancing lower (displacement ratio ≤ 3%).