Experimental Study of Precast Bridge Columns with Built-In Elastomer

Abstract

Two one-third-scale precast concrete segmental column models with energy-dissipating plastic hinges were designed and tested on a shake table at the University of Nevada, Reno. Conventional reinforced concrete was used in the plastic hinge of one column (SC-2). In the other model, a built-in elastomeric pad integrated with the footing and a concrete segment constituted the plastic hinge (SBR-1). The purpose of using the pad was to minimize damage while dissipating energy through yielding of the longitudinal bars and deformation of the pad. Both columns were subjected to the same ground motion as was recorded at the Sylmar station during the 1994 Northridge, California, earthquake with increasing amplitudes until failure. Compared with conventional precast concrete segmental columns, both SC-2 and SBR-1 showed superior performance, such as minimal residual displacement and larger energy dissipation. SBR-1 with the elastomeric bearing pad dissipated more energy and was free from damage in the plastic hinge zone.