Experimental Study On Seismic Behaviour Of Core Steel Reinforced Concrete Columns

Core steel reinforced concrete(CSRC) column is a new structural technique which is developed from setting H-shape steel with little hight at the core of reinforced concrete column section. Core steel can effectively improve the columns' seismic behaviour and increase the limit value of the axial compression ratio regulated by code to meet the requirement of the practice of engineering.Five rectangular CSRC columns specimens with a span-depth ratio 3 have been tested under cyclic loading to investigate the effect of the core steel on the seismic behaviour of the reinforced concrete columns with high axial compression ratio. The main tested parameters are the ratio of core steel ρ_α, the axial compression ratio n and the compressive strength of the concrete, f_c. Based on the nalysis of the failure mode, hysteretic behaviour, skeleton curves, deformation capacities and energy dissipation capacities, the excellent seismic behaviour of CSRC columns is validated. From the test results, the following conclusions can be derived. (1) Test results indicate that the developing of shear cracks can effectively restrained and the deformation capacitiy and hysteretic energy dissipation capacity. (2) The vertical load carrying capacities are tend to be stable during the specimens experienced large plastic deformation. (3) The seismic behaviour of columns with an axial compression ratio exceed the limit value regulated by Code is considerably enhanced. (4) The ratio of core steel ρ_α has great effect on the deformation capacity of CSRC specimens. Note that the ratio of core steel should match the axial compression ratio of RC columns.