The improved seismic performance and cost-effectiveness of two innovative performance enhancement technologies in typical reinforced concrete bridge construction in California were assessed in analytical and experimental studies. The technologies considered were lead rubber bearing isolators underneath the superstructure and fiber-reinforced concrete for the construction of bridge columns.
Pushover and time history analyses were carried out for the different bridge systems. The analytical model of the fiber-reinforced concrete bridge was calibrated based on bidirectional cyclic tests on two cantilever column specimens. The PEER PBEE methodology was used to compute the post-earthquake repair cost and time of the bridges over their lifespan of 75 years. A financial analysis was performed accounting for the epistemic uncertainty and a wide range of interest rates.
Despite slightly higher construction costs, considerable economic and structural benefits were obtained from the use of the two techniques considered. The isolation of the bridge superstructure resulted in a significant reduction in column and abutment displacement and force demands, as well as reduced repair time and indirect economic losses. The experimental and analytical results demonstrated that under cyclic loading the use of fiber-reinforced concrete leads to improved damage-tolerance, shear strength, and energy dissipation, compared to conventionally reinforced concrete columns.
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