Seismic tests of concrete columns with light transverse reinforcement

Earthquakes and laboratory experience show that columns with inadequate transverse reinforcement are vulnerable to damage including shear and axial load failure. To study this behavior four full-scale columns with light transverse reinforcement were tested quasistatically under unidirectional lateral load with either constant or varying axial loads. Test results show that responses of columns with nominally identical properties vary considerably with magnitude and history of axial and lateral loads. Observed behavior is compared with expected behavior based on available analytical models. The FEMA 356 assessment model predicted the column strengths well, but underestimated the displacements.