Seismic Behavior Of Reinforced Concrete Short Columns With Minimum Reinforcements

Four reinforced concrete short columns with Minimum reinforcements aresubjected to reversed cyclic loading, in order to investigate the influence of variouslongitudinal reinforcement ratio，transverse reinforcement volumetric ratio and value ofρs·fyvon ductility and energy dissipation. The paper is as follows:①The variable in two reinforced concrete short columns which belong to thegroup1with500MPa steel is longitudinal reinforcement ratio（0.6%、1.06%）. The shearspan ratio, axial compression ratio, and volumetric ratio of lateral reinforcement ofthese specimens are respectively1.5,0.8and1.2%. The main purpose of thiscomparison is to study the influence of longitudinal reinforcement ratio on seismicbehavior in the condition of tie volumetric ratio is equal to low limit value1.2%whichis the Code reqires short columns.②Another two reinforced concrete short columns are compared, which belong togroup2. To investigate the influence of tie volumetric ratio on seismic behavior，both ofthem use tie which yield strength reach567MPa and concrete which strength reach C50,and the experimental parameters are the same as the group1, except that tie volumetricratio is respectively increased up to1.48%and1.97%.Based on analysing statistics and comparing test results, the conclusions areconcluded: Firstly, the specimens which satisfy the Three seismic rate reinforcementrequirement can not meet plastic deformation requirements and perform typical brittleshear failure. Secondly, the tie average confinement stress ρs·fyvis a importantparameter which influence plastic deformation ability and increasing value of ρs·fyvsignificantly improve deformation capability when the value of ρs·fyvless than3.5, evenif the columns have the same tie volumetric ratio（1.5%，2.0%）, those with higheryield strength tie in higher axial compression ratio performed better than those withlower yield strength in lower axial compression ratio.