Research On Eccentric Compression Performance Of Reinforced Concrete Columns With Circular Composite Spiral Stirrups

The load capacity of the concrete column after the spiral stirrup is obviously improved,and it has good energy dissipation performance and seismic performance.And the application of rectangular pillars in engineering is more extensive and mostly eccentric compression.Therefore,this paper presents the research on the eccentric performance of spiral stirrups.In this paper,six sets of circular composite spiral stirrups,a group of diamondshaped ordinary composite stirrups and a group of rectangular ordinary composite stirrups has been tested in eccentric experiment.The effect of this hoop pattern on the bearing capacity and ductility of the columns with circular spiral stirrups is studied.The strain of the concrete,the longitudinal reinforcement,the spiral stirrup and the ordinary stirrups in the compression process are analyzed.And the variation of the eccentric performance with the reinforcement spacing,eccentricity and hoop form was studied.The ABAQUS modeling and analysis process of the spiral stirrups is introduced,and the comparative analysis is carried out with the test.ABAQUS describes the pressure process in more detail in the form of stress cloud image.Both the test and the finite element simulation show the following trends :1.The eccentricity control circular helix in the failure mode of the stirrups,the load-bearing capacity decreases and the load-displacement curve tends to be gentle with the increase of the eccentricity.2.The tightening of the stirrups can effectively improve the carrying capacity and the deformation ability.The shape of the hoop of the circular spiral stirrup is compared with that of the traditional hoop,and the restraint effect is more obvious under the same hoop ratio.3.The elasticity of the load-displacement curve is large,and the bearing capacity is higher,the stage constraint is stronger.Finally,the eccentric compression bearing capacity of the circular spiral stirrups is proposed by using the superposition method,and the calculated results are obtained with great precision.