Experimental Study On Bond Behavior Of Concrete-filled Precast Concrete Tubular Column

Concrete-filled precast concrete tubular(CFPCT)column is a new type of composite concrete column structure proposed by Tianjin University,which is a structure with concrete poured in the precast tubular,as well as certain steel bars and profiles equipped in the precast tubular.It has the characteristics of easy quality assurance,fast construction speed,good overall force form,wide application scope and low cost,and has better development advantages in various industries.As the CFPCT column is a new type of composite structure,its bond strength has not yet been solved and studied,so it has important practical and theoretical significance to carry out such research.In this dissertation,12 CFPCT columns with different concrete strength,surface state and interface length are taken as the research objects,and the interfacial bond strength of the CFPCT columns and its influencing factors are studied through the axial push-out test.Through the study of the whole process of the axial push-out test,it is found that both the strength and interface state of the precast concrete tubular have obvious influence on the interface bond strength of the new CFPCT column,but the change of the interface length has no obvious regularity on the bond strength,and the failure modes of all the specimens are basically the same during the test.Based on the cohesive model in ABAQUS,a non-linear finite element analysis model of new CFPCT column for Push-out experiment is established,and the model is modified based on the experimental results.Then,the stress,bond and relative slip along the loading direction of the precast concrete tube,core concrete and their interfaces are studied.The numerical model modified on experiment can reflect the mechanical characteristics of CFPCT well.The experimental and numerical analysis results have certain reference value for further research on the bond behavior of the CFPCT column.