Experimental study on seismic behavior of steel reinforced concrete rectangular column with unsymmetrical cross-shaped steel section

In order to adapt to the characteristics of uneven stress on the side and corner columns of steel reinforced concrete (SRC) frame structures, simplify the construction, and avoid a large number of steel openings and steel welding, SRC rectangular column with unsymmetrical cross-shaped steel section was proposed. Low cyclic loading tests were carried out on seven asymmetric and one symmetric SRC rectangular columns with cross-shaped steel section. The effects of steel configuration, shear span ratio, axial compression ratio and volume stirrup ratio on seismic performance of columns were investigated. The results show that the asymmetrical steel distribution makes the positive and negative bearing capacity of the SRC column asymmetrical, and the positive loading (compression on the inner side of the section steel) reaches the peak load earlier than the negative loading. Under the same steel ratio, SRC rectangular columns with unsymmetrical cross-shaped steel section can achieve similar seismic performance to the symmetrical steel form. The increase of shear span ratio reduces the stiffness decay rate of the column, increases the ductility and improves the energy dissipation capacity. With the increase of axial compression ratio, the stiffness degradation of column becomes worse, ductility decreases and energy dissipation capacity weakens. The energy dissipation capacity and ductility of the column can be improved by increasing the volume stirrup ratio.