Abstract: Steel reinforced concrete-reinforced concrete (SRC-RC) vertical hybrid structure is a special form with steel-reinforced concrete (SRC) columns in bottom floors and reinforced concrete (RC) columns in upper floors. SRC-RC transfer columns in the special hybrid structure are used to link the SRC columns below and the RC columns above. As shape steel partially exists in SRC-RC transfer columns, the cooperation problem between the shape steel and the concrete is serious, which causes SRC-RC transfer columns to fail in special patterns. In the investigation, by the low-cycle reversed loading experiments of sixteen SRC-RC transfer columns and one reinforced concrete column, the cooperation between the shape steel and the concrete is discussed and a mechanics model is constructed. The results show that (1) the proposed mechanics model can preferably illuminate the transmission of internal force between the shape steel and the concrete and can be used to analyze the failure mechanism of SRC-RC transfer columns; (2) with the increase of the ratio of shape steel area to section area, the shape steel bears more shear force and the damage of the concrete is more serious during the whole loading process; and (3) for some specimens, doubling the amount of stirrup at the area where shape steel is discontinuous or doubling the amount of stirrup all over the column both can obtain a better effect, and the increment of stirrup can relieve the partially- existed adverse effect of shape steel effectively; and (4) diminishing the ratio of shape steel area to section area helps improve the hysteretic performance and deformation ability of specimens.

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