Experimental Study On Mechanical Behavior Of High Ductile Concrete Members Under Eccentric Compression

High ductile concrete(HDC)with high strength,high ductility,high crack resistance,high energy absorption and damage resistance,especially is able to with multiple fractures and strain hardening characteristics under tension together shear loads,which can improve the brittleness of concrete,Can significantly improve the structure of the ductility and resistance to damage.Improve the seismic performance of components,with a wide range of applications.In order to take advantage of the good pressure deformation ability of HDC,improve the brittle failure mode of the members under small eccentric compression,study the application of HDC to the performance and deformation of eccentric compression members,this paper analyzes the performance of HDC members under eccentric compression by means of experimental study and numerical simulation.Based on the relationship between flat section assumption and HDC constitutive relation,The balanced relative depth of compressive area of the HDC members under eccentric compression is calculated,The calculation method of cross section compression capacity of HDC members under eccentric compression is proposed.The main research contents and achievements are as follows:(1)Experimental study on the force behavior of HDC columns under eccentric compression.Two RC columns under eccentric compression and six HDC columns under eccentric compression were designed.The failure process,failure mode,bearing capacity and deformation capacity of the specimen were analyzed by static load experiment.The experiment results show that the failure of the specimen can be divided into small eccentric compression and large eccentric compression.Compared with the failure characteristics of the RC bias column,the failure of the HDC columns under eccentric compression is more ductile,especially for small eccentric compressive columns;RC and HDC have good deformation coordination ability with steel bar;HDCmaterial can significantly improve the deformation ability of members under small eccentric compression.(2)Theoretical analysis of cross section compressive bearing capacity of HDC members under eccentric compression.Based on the assumption of flat cross section and the constitutive relation of HDC,the calculation method of equivalent rectangular stress graph coefficient is used to calculate the cross section compressive bearing capacity of HDC members under eccentric compression.The theoretical calculation results are compared with the experimental results.,which show good consistency with the experimental results.And then,the balanced relative depth of compressive area of HDC members under eccentric compression is derived and compared with that of reinforced concrete members under eccentric compression.(3)Finite element analysis of stress behavior of HDC columns under eccentric compression.In this paper,the finite element software ABAQUS is used to simulate the two reinforced concrete eccentric columns and six HDC columns under eccentric compression,and the results are compared with the experimental results.The results show that ABAQUS can well simulate the peak load and displacement of the specimen,the stress distribution and the crack development of each component,and prove the reliability of the finite element model.And the influence of HDC compressive strength and HDC ultimate tensile strain on the bearing capacity of HDC columns under eccentric compression was studied.