Abstract:
The pseudo-static tests of one concrete short column (CSC) without fire, one CSC after fire, one CSC without fire action and strengthened with CFRP, and three CSCs after fire and strengthened with CFRP were carried out to investigate the influence of CFRP usage and wrapping manner on strengthened seismic performance of CSCs after fire. A practical method to calculate the shear strength of concrete columns after fire and strengthened with CFRP was suggested. Results show that the shear strength of CSCs wrapped with CFRP is increased by 21.8% compared with those without wrapping. The shear strength of CSCs firstly exposed to fire followed by wrapping with CFRP is about 111.2%~117.1% of those without either fire action or wrapping. CFRP wrapping can enhance the ultimate deformation and hysteretic energy dissipation of CSCs both without fire action and after fire, but comparing to those without fire action, CFRP wrapping can’t increase the secant stiffness of CSCs after fire. For the same CFRP usage, the shear strength of columns wrapped entirely is slightly better than those wrapped with strips. The hysteretic rules of CSCs for cases without fire action, after fire, without strengthening and with strengthening are similar.