SHAKE TABLE TESTS OF REINFORCED CONCRETE BRIDGE COLUMNS THAT RE-CENTER FOLLOWING EARTHQUAKES

Abstract

To minimize residual displacements in reinforced concrete columns, a design is proposed whereby a longitudinal post-tensioning tendon replaces some of usual longitudinal mild reinforcing bars. The seismic performance of such partially prestressed, reinforced concrete columns was investigated through a series of earthquake simulator tests. The effects of unbonding of longitudinal mild reinforcement and providing a steel jacket were also investigated. The partially prestressed, reinforced concrete columns studied performed remarkably well under strong ground excitations. Very small permanent deformations were observed after the tests, especially when the longitudinal mild reinforcement was unbonded and a steel jacket was provided.