Experimental study of reinforced concrete rocking columns with steel tubes under cyclic loading

To reduce damage and enhance the seismic resilience of reinforced concrete (RC) columns, this study introduces a new type of RC rocking column installed with steel tubes for end protection and steel angles as external dampers to enhance the energy dissipation capacity. Six full-scale specimens including four RC rocking columns without steel angles and two with steel angles were tested under cyclic loading. The results demonstrate that the proposed end protection measure significantly mitigates the damage to RC rocking columns. The residual deformation of specimens was small after testing. As the axial compression ratio increases, the strength of RC rocking columns also increases. However, a higher axial force results in greater damage and increased residual deformation. Steel angles significantly enhance the strength, stiffness, and energy dissipation capacity of RC rocking columns. Additionally, the repair of the RC rocking column is straightforward, and the recovery of its function is rapid after strong earthquakes.