Shaking Table Tests on Reinforced Concrete Frames without Seismic Detailing

Four reinforced concrete frame specimens were tested on a shaking table with the objective to observe the interaction of structural elements at the onset of collapse. Each specimen consisted of a 1/2.25 scaled model of a two-bay, two-story reinforced concrete frame without seismic detailing. The specimens were tested under moderate and high column axial loads to investigate the influence of axial load on the collapse vulnerability of nonductile columns in a structure. These tests enable study of the interaction of the beams, columns, and joints as collapse is initiated. This paper presents the observations during the tests and comparison of response of the specimens. In particular, the test results suggest that collapse of a concrete frame due to failure of unconfined beam-column joints is less likely compared with collapse due to failure of nonductile columns.