EXPERIMENTAL RESEARCH ON THE SHEAR-BOND FAILURE OF RC COLUMNS UNDER SEISMIC ACTION

Shear-bond failure is an important failure mode for reinforced concrete (RC) structures subjected to seismic actions. The quasi-static test for 16 specimens with the aspect ratio between 1.5―2.5 was conducted to study the aseismic performance of RC columns. The failure patterns, ductility and dissipated energy parameters, degradation of stiffness and shear strength of the specimens are studied. The test results indicate that the specimens were dominated by shear and bond failure, including flexural-shear, shear and bond failure modes. The specimens with flexural-shear failure show good ductility and energy dissipating capacity, while the specimens with bond failure have clearly “pinching effect”, poor ductility and energy dissipating capacity and faster stiffness degradation, which leads to a non-ductile behavior of the specimens. Also, short columns with aspect ratios between 1.5―2.0, tensile longitudinal reinforcement ratios exceed 1.0% and low concrete strength were vulnerable to bond failure, on which more attention should be paid in aseismic design.