Experimental investigation on hysteretic performance of reinforced concrete columns under constant axial compression and cyclic reversed flexure-shear-torsion loading
Li Juntao1 Chen Zongping2,3 Wang Huanhuan2 Chen Yuliang2
1. Xi’an University of Architecture & Technology, Xi’an 710055, China;
2. College of Civil Engineering and Architecture , Guangxi University, Nanning 530004, China;
3. Key Laboratory of Disaster Prevention and Structural Safety of China Ministry of Education, Guangxi University, Nanning 530004, China
Abstract：To study the reinforced concrete columns hysteretic behavior under constant axial compression and cyclic reversed flexure-shear-torsion loading, six specimens were designed and tested, in which the torsion-bend ratio, shear-span ratio, reinforcement ratio and stirrup ratio were considered, and cyclic loading with different displacements and amplitudes was performed. The failure modes and the relation curves between the torsion forces and the torsion angles for specimens were obtained. Based on the experimental data, the influences of abovementioned four parameters on the hysteretic performance were analyzed. The test results indicate that the failure patterns of specimens mainly appeared as bend-torsion composite failure, in which the cracks are diagonal and almost concentrates in the root. The torque-twist angle hysteresis back curve is full with enhanced energy dissipation capacity when the torsion bending rate and the reinforcement ratio are increased. As the torsion, the bending rate as well as the reinforcement ratio increase, the torque-twist angle hysteresis back curve becomes smoother, and more energy is dissipated. When the shear span rate increases, the torque-twist angle hysteresis back curve becomes more pinching, less energy is dissipated and the flexural ductility is improved. By increasing the torsion bending rate, the reinforcement rate and the stirrup rate, the flexural ductility of the specimen can be improved and the degradation of the rigidity and stiffness can be slowed down.
