Study on Seismic Performance Curves of Reinforced Concrete Columns Failed in Shear

Study on Seismic Performance Curves of Reinforced Concrete Columns Failed in Shear

During the 921 Chi-Chi Earthquake, a lot of reinforced concrete buildings failed in shear condition. Shear failure is brittle and therefore should be avoided. In order to provide ventilation, mounting of air conditioner, door frame, etc. most often extreme-short columns are encountered. These columns will be the weakest elements due to its small lateral displacement. Thus, this research is aimed to study the seismic resistant behavior of extreme-short columns under constant axial force through observation in laboratory experiments and analysis. There are several important variables which can affect the strength and behaviour of extreme-short columns, i.e. aspect ratio, axial load magnitude, and stirrup detailing. Eight specimens were tested under double curvature and constant axial load by repeating loading test to observe their behaviour under shear and axial failure. Test results show that under different magnitude of axial load, the collapse behaviour will be different in a sense that higher axial load can accelerate the failure mechanism. Columns with transverse reinforcement using ductile detailing can resist higher lateral force and lateral displacement capability.