Experimental Study On Reciprocating Load Of Concrete Columns Confined In Steel-channel Steel Area

With the rapid development of the high-rise buildings and the limit of seismic fortification requirements, the bottom column of the frame is bound to increase its section size due to the larger axial force. Which leads to the results of a waste of materials and the reduce of the effective use of the space. Even it may cause the brittle failure because of the "short column". Under the view of this situation, the prevailing approach is to use steel reinforced concrete,which takes the advantage of the structural steel to bear the part of the axial force. However, this method has a significant increase in the amount of steel while has little contribution to the seismic performance of the column.Rebar – channel steel regional confined concrete columns which uses channel steel instead of part steel bar,through it to provide more constraint area and the lateral stiffness is more greater than the longitudinal reinforcement’s, with a stirrup to provide effective constraints, so as to improve the further bearing capacity and seismic performance of the component.In this paper, through the low cyclic loading test of rebar – channel steel regional confined concrete columns which have five different axial compression ratio and stirrup spacing, get the law of the failure forms, hysteretic curve, skeleton curve, ductility coefficient, inter layer drift angle, horizontal bearing capacity, energy dissipation capacity and stiffness degradation. The paper analysis the impact that the different axial compression ratio on the seismic performance of the component under the same stirrup spacing,and finds out reasonable axial compression ratio value. In the meantime,it also analysis the influence that different stirrup spacing on the seismic performance of the component under the same axial compression ratio.With the ABAQUS software, conducting the finite element simulation analysis of rebar – channel steel regional confined concrete columns, analysis the effects of the expansion angle, viscosity coefficient and damage factor on the hysteretic behavior of the specimens, finds out suitable parameter of finite element model, obtains the hysteretic curves, skeleton curves, load bearing capacity and other seismic behavior of the components.At last, makes compare with the results of each pieces of the test and the results of ABAQUS finite element analysis.