Time-Dependent Behaviors of RC Columns Subjected to Sustained Eccentric Loading

Long-term effects such as creep and shrinkage can affect the stiffness and strength of RC columns. Especially, for the columns subjected to sustained eccentric load, since both axial shortening and lateral drift increase during sustained load duration the earthquake resistance of the columns can be significantly reduced due to the long-term effects. In the present study, the long-term behavior and the earthquake resistance of RC columns subjected to sustained eccentric load were evaluated. The column specimens were subjected to lateral monotonic or cyclic loading after sustained concentric or eccentric axial loading for the prescribed duration. A new test set-up using post-tensioning was introduced to sustain the axial load of long duration. From the test, the long-term deformations of the columns due to sustained load, such as axial shortening and lateral drift, were investigated. In addition, the long-term effects on the earthquake resistance such as stiffness, strength, deformation capacity, and energy dissipation capacity were evaluated.