Experimental study on seismic performance of concrete-encased concrete-filled steel tube column and RC beam joint

This paper studies the seismic performance of a novel concrete-encased concrete-filled steel tube column and reinforced concrete beam composite joint. In order to gain insight into the seismic performance of the joint, a pseudo-static test was conducted on an actual engineering joint specimen with a scale ratio of 1:2. The specimen was subjected to a loading method comprising the application of a constant axial force to the top of the column and a cyclic load to the end of the column. Employing experiments and in conjunction with digital image correlation technology, the failure process and characteristics of such joints were subjected to detailed analysis, and the variation laws of the bearing capacity, deformation capacity, strength and stiffness degradation, seismic ductility and energy dissipation capacity of such joints were investigated. The results demonstrate that when subjected to a combination of constant axial pressure and lateral cyclic load, the joint exhibits a beam end bending failure mode, characterised by ductility. The maximum drift ratio reached was 5%. The joint displays excellent seismic performance when subjected to cyclic loading.