Cyclic behavior of concrete-encased high-strength concrete-filled steel tube composite walls: An experiment

Concrete-encased high-strength concrete-filled steel tube (CFST) walls are a new type of composite shear wall embedded into high-strength CFST columns as a boundary element and/or in the centre of a wall. To examine the cyclic behavior of the concrete-encased CFST composite wall, ten wall specimens were designed, and tested under lateral cyclic loading. The performance parameters of each specimen, including the failure pattern, hysteresis characteristics, load-bearing capacity, ductility, stiffness, and energy dissipation capacity were studied. The experimental results demonstrated that the concrete-encased CFST walls have a high initial stiffness and load-bearing capacity. The degradation of the load-bearing capacity and stiffness is slow, the ductility of the composite wall is excellent, and the hysteresis curve of the wall is complete under cyclic loading, which indicates a good cyclic behavior. The specimens maintain a good ductility and energy dissipation capacity, even at a high axial compression ratio. The CFST columns embedded in the centre of a wall enhance the load-bearing capacity and change the distribution and propagation direction of cracks.