Experimental Study On Seismic Behavior Of Checkered Steel Reinforced Concrete Column

Aiming at the problem of low bearing capacity and low ductility due to the weak bond between profile steel and concrete under the condition of moderate shear span ratio,this paper presents a new type of checkered steel reinforced concrete column.The purpose of this paper is to use the checkered steel to replace the profile steel to enhance the seismic performance of the steel reinforced concrete column under the action of the low cyclic.Three specimens with shear bond failure under low cyclic loading are designed.Two of the specimens are checkered steel reinforced concrete columns,the change factor is the height of the checkered pattern,and the other specimens are normal steel reinforced concrete columns for reference.The research focuses on: the seismic behavior of the checkered steel reinforced concrete column and the difference between the checkered steel reinforced concrete column and the ordinary steel reinforced concrete column;the distribution of the bond stress of the checkered steel reinforced concrete column,the influence of the checkered pattern height and the presence or absence of the checkered pattern on the bond strength;the relationship between the micro-level bond strength and the macro-level seismic performance.The hysteretic curve,skeleton curve,ductility and energy-dissipating capacit of the checkered steel reinforced concrete column are obtained by test of 3 specimens at low cycle loading.The general seismic performance of the checkered steel reinforced concrete column and its difference from that of the steel reinforced concrete column are obtained through analysis and comparison.At the same time,the strain distribution of the profile steel is obtained.Combining with the bonding mechanism between checkered steel and concrete,a method for calculating the bond stress between checkered steel and concrete is theoretically derived.The size and distribution of the bond stress along the column height under different loads are obtained.This paper analyzes the influence of the checkered pattern height and the presence or absence of the checkered pattern on the bond strength in the micro-level,and its relationship with the macro-level seismic performance,and obtains the calculation formula of shear bearing capacity related to checkered pattern height.