Experimental study on seismic performance of reinforced concrete square columns under compression, bending, shear and torsion

To reveal the failure mechanism of reinforced concrete columns under cyclic loading of compression, bending, shear span, reinforcement ratio and stirrup ratio, the low cycle cyclic loading tests of six specimens were completed with synchronous but different displacement amplitude loading modes, and the test data were obtained to analyze the influence of various parameters on seismic performance. The test results show that: cracks are mainly concentrated in the middle and lower section of the specimen, showing oblique cross form, and the failure mode is mainly in the bending and torsion failure mode; with the increase of torsion bending ratio and reinforcement ratio, the torque torsion angle hysteretic curve of the specimen is fuller and has strong energy dissipation capacity; with the increase of shear span ratio, the torque torsion angle hysteretic curve of the specimen presents a pinching shape, and the energy consumption capacity becomes worse, but it changes later The flexural ductility and energy dissipation capacity of the specimens can be improved by increasing the torsion bending ratio, reinforcement ratio and stirrup ratio, and the degradation of strength and stiffness can be delayed.