EXPERIMENTAL RESEARCH ON SHEAR PERFORMANCE OF RC FRAME COLUMNS WITH DIFFERENT AMOUNT OF STIRRUPS IN TWO PRINCIPAL DIRECTIONS UNDER SKEWED HORIZONTAL CYCLIC LOADS

Three RC frame columns are tested under two-way horizontal cyclic loads. Based on the testing results, as well as those of previous experiments, the seismic behaviors of RC frame columns with different amount of stirrups are researched in this paper. The hysteretic behavior, rigidity degeneration, ductibility and capability of energy dissipation are analyzed by loading the structures in two principal directions. Experimental results show that the hysteretic behavior is poor and the rigidity degeneration is not significant during the early loading stage but turns out to be significant after cracks occur. Results also indicate that the ductility factor and the ultimate rotation angle of the columns increase with the increasing of load angle. Moreover, the capability of energy dissipation is maximized in the case of 0o load angle, and the variation is small if the load angle varies between 15o and 75o.