Effects of reinforcement connection types and loading angles on prefabricated concrete column seismic performance

This study aimed to determine the seismic performance differences between prefabricated concrete columns with grouted sleeves (PCgs columns) and prefabricated concrete columns with slurry anchors (PCsa columns), as well as the effect of different horizontal loading angles on the seismic performance of PCgs columns. In addition to a control cast-in-place column (CIP column), three PCgs columns and one PCsa column were planned and manufactured as precast concrete column specimens. All samples were made with the same reinforcement, hoop rate, and concrete strength. Static tests were used to test the impacts of various loading angles and reinforcement connection forms on the damage morphology, hysteresis curve, skeleton curve, energy dissipation, stiffness degradation, ductility, and reinforcement strain of each specimen. The experimental results were validated, and the phenomenon was further explored by performing a finite element analysis of the model and then performing the calculations in XTRACT software. The results indicate that the loading angle significantly impacts the seismic performance of PCgs columns. As the horizontal loading angle increases, the peak bearing capacity of PC columns decreases while the flexural bearing capacity increases and then decreases. The initial cracking location of PCsa appears in the middle of the pre-buried bellows; compared with the CIP column under the oblique 45° loading angle, the reinforcement connection method has a greater impact on the seismic performance of PC columns under the same loading angle; compared with the CIP column under the low circumferential reciprocal cycle, the development of cracks in PC columns body is less, and the later crack development is concentrated at the connection joints; the most unfavorable sections that may occur are the connection joints, the section at the joint at the bottom of the column has a high shear bearing capacity and positive section compression bending failure occurs.