The Axial Compression Bearing Capacity Design Method Research Of Steel Reinforced Concrete Rectangular Short Column Confined By Carbon Fiber Reinforced Polymer

The priority effect of Fiber Reinforced Polymer（abbreviation for FRP）on the constraint of reinforced concrete structure is to improve the bearing capacity.There are many factors that can influence the effect of FRP material constraints,including corner radius,aspect ratio and confining manners.The effect of these parameters on the compressive strength model and bearing capacity of steel reinforced concrete rectangular column（SRC）was analyzed,and the CFRP constraints rectangular short column axial compression test was designed,which considered the reinforcement ratio.At last,the superposition formulation of the axial bearing capacity of SRC rectangular short columns confined by CFRP was proposed.Before this paper,I have read a lot of domestic and foreign documents,by collating and summing up several existing typical containing corner radius constraint models of concrete strength,selecting a more suitable one for containing corner radius parameters of large size rectangular column.According to the effect of the characteristics of rectangular section on lateral restraint stress,the lateral restraint stress distribution is also different with the change of aspect ratio.The lateral restraint stress model was modified and more suitable for rectangular columns.Then fitting out the strength model of aspect ratio based on the corner radius parameter.Compared with the strip interval coefficientsk_g,containing fiber characteristic value_f?can better reflect the constraint effect of strip constraints.But when stripe width and spacing is equivalent,containing fiber characteristic value_f?cannot fully reflect the effect of the specimens with strip constraints.The strength ratio parametersk_sf was introduced with the test data.Five specimens were designed and loaded,which considers the reinforcement ratio.The failure process was very similar,longitudinal reinforcement and steel yield,then core concrete section crushed,finally CFRP reached ultimate tensile strain.With the increase of reinforcement ratio,bearing capacity and ductility increased gradually.There is high strength constraint zone in the steel flange and web because of the restriction of flange.The section of concrete constraint zone was divided into three parts:unconfined,partially confined and highly confined concrete.Combined with the related tests and simulation studies,the value of highly confined factork_h is 1.1.At last,considering the different confined concrete area in columns section,the superposition formulation of the axial bearing capacity of SRC rectangular short columns confined by CFRP was proposed,verify according to the test data.