Compressive and flexural behavior of prefabricated concrete-filled steel tubular columns with bolted splices

Abstract Concrete-filled steel tubular (CFST) structures are technically advantageous for prefabrication because of the easy connection between steel tubes and other prefabricated components. For prefabricated CFST columns, reliable column-column connections are the key to structural integrity and a safe load transfer. Current engineering practice has limited examples regarding the design and detailing of prefabricated CFST column-column connections, and very few tests have been conducted on such connections in previous studies. This study attempts to propose three types of bolted prefabricated column-column connections (splices). A total of 19 specimens with the proposed splices were tested under either axial compression or flexural bending. Strength capacity, stiffness, strain distribution and ductility of these spliced members are investigated, and effects of different tube end conditions and loading scenarios on the member behavior are also discussed. Furthermore, the applicability of various design provisions in predicting the axial and flexural capacities of these spliced members is investigated. At last, suggestions on the selection and detailing of the proposed column splices are provided.