RESEARCH ON THE SEISMIC PERFORMANCE OF HIGH-STRENGTH CONCRETE COLUMNS WITH HIGH-STRENGTH STIRRUPS

Reversed cyclic loading tests for 6 high-strength concrete (HSC) columns and 3 normal strength concrete (NSC) columns (for comparison) are conducted to evaluate the seismic behavior of HSC columns with high-strength stirrups (HSS). The failure patterns, hysteretic curves, ductility and dissipated energy parameters and shear strength of the specimens are studied and compared with each other. It is found that the failure patterns of the HSC columns are similar with NSC columns and all of them suffered flexural-shear failure modes. HSC concrete will decrease the axial load ratio of the column, which will be beneficial for the ductility of the columns. The shear strength of HSC columns with HSS are compared with ACI 318 and GB 50010-2002 codes, it is founded that both the codes would overestimate the shear strength of the columns and one should pay more attention in the design. The fiber element software USC_RC based on Mander model for confined concrete could also be used to simulate the flexural strength of HSC columns with HSS.