Seismic performance of RC columns strengthened with HSSSWR meshes reinforced ECC under high axial compression ratio

Abstract

The cyclic loading tests under high axial compression ratio were performed to investigate the seismic performance of full-scale reinforced concrete (RC) columns strengthened with high-strength stainless steel wire rope (HSSSWR) meshes reinforced engineering cementitious composite (ECC), considering different axial compression ratios and strengthening schemes. The test results show that the seismic performance of RC columns was greatly improved after being strengthened. Specifically, the failure modes of the columns were changed from flexure-shear failure to compression-flexure failure, and the ductility and energy dissipation capability were significantly improved by 69.6% and 474.6%, respectively. Besides, the HSSSWR meshes reinforced ECC jacket was confirmed to be a more efficient strengthening scheme, compared with strengthening with only ECC or lateral HSSSWRs reinforced ECC. The RC columns still showed good ductility and energy dissipation capacity after being strengthened with HSSSWR meshes reinforced ECC under high axial compression ratios of 0.5 and 0.7. Finally, taking into account the confinement effects of ECC, lateral HSSSWRs, and stirrups, an analytical model used for predicting the envelope curve of strengthened columns with HSSSWR meshes reinforced ECC jackets under cyclic loading was proposed, which was in good agreement with the test results.