Deterministic and Probabilistic Lifecycle Cost Assessment: Applications to Nebraska Bridges

Abstract

The main purpose of this paper is to utilize lifecycle cost analysis (LCCA) as a decision-support tool for three commonly encountered decisions in bridge management: bridge deck overlay decisions, expansion joint replacement decisions, and deck widening versus deck replacement decisions. Bridge management systems aim to assess investment decisions and identify the most cost-effective improvement alternatives to ensure the safety and serviceability of bridge networks. To achieve this goal, the recently developed deterioration models and cost data for highway bridges in the state of Nebraska are utilized in conducting LCCA using deterministic and probabilistic approaches. For deck overlay decisions, silica fume overlay, epoxy polymer overlay, and polyester overlay are compared with bare deck with respect to lifecycle cost and structural life. In expansion joint replacement decisions, two alternatives are compared: relocating abutment expansion joints at the grade beam and replacing abutment expansion joints at the same place. Deck widening is compared with deck replacement under five different bridge conditions. The results of the analysis indicate that applying an epoxy polymer overlay on bare deck with a condition rating of 7 is the most cost-effective deck overlay decision, replacing an abutment expansion joint at the same place is more cost-effective than relocating them at the grade beam, and deck widening is significantly more cost-effective than deck replacement in most cases.