INFLUENCE OF STEEL RATIO ON SEISMIC PERFORMANCE OF STEEL REINFORCED CONCRETE SPECIAL-SHAPED COLUMN

Sixteen steel reinforced concrete special-shaped column specimens were designed, including four L-shaped columns, four T-shaped columns loaded along the web, four T-shaped columns loaded along the flange, and four cross-shaped columns. The influence of steel ratio on seismic performance of a steel reinforced concrete special-shaped column was analyzed by using tests and finite element analysis. The failure patterns and seismic behaviors, such as hysteretic loops, skeleton curves, strength, ductility, stiffness and energy dissipation capacity, were obtained. The research results show that the failure pattern of all tested specimens with a shear span ratio of 2.5 was flexural failure. The influence of steel ratio on the failure pattern of specimens is not obvious, but as the steel ratio increasing, the cracking of the concrete can be inhibited and the damage of the specimens can be delayed. The hysteretic loops were symmetric and plump. The ductility and energy dissipation capacity were good, and the stiffness degenerated from fast to slowly. With the increase of steel ratio, the area of hysteretic loops becomes larger and larger, the bearing capacity and ductility are significantly improved, and the speed of stiffness degradation slows down. But the steel ratio has no significant influence on the energy dissipation capacity of specimens.