Dynamic Experimental Study on RC Interior BCJs under Cyclic Loading at Column Ends

Abstract

Concrete and steel are typical rate-dependent materials. Therefore, the dynamic behavior of reinforced concrete (RC) members is inevitably affected by the loading rate. To study the effect of the loading rate on the behavior of RC beam–column joints (BCJs), a dynamic test was carried out on RC BCJs. Cyclic loading with various loading rates was applied to the column end of RC BCJs to simulate horizontal earthquake excitation. The final crack morphology and the first principal stress contour plots of BCJs indicate that dynamic loading can promote the shear effect in the core region of RC BCJs. The lower the shear span ratio is, the higher the loading rate and the more obvious the effect. Experimental results show that the yield strength and ultimate strength of BCJs are approximately linear with the logarithm of the loading rate. There is no obvious effect of the loading rate on the yield, ultimate, and failure displacements of the BCJ, but the shear angle of the core region is approximately linear with the logarithm of the loading rate. In addition, the effects of the loading rate on the stiffness degradation, ductility, and energy dissipation capacity are studied.