Bridge Deterioration Rates and Durability/Longevity Performance

Abstract

A factor that typically receives too little consideration in bridge work is durability, and the time to begin thinking about durability is at the beginning of the bridge planning and design phase. Once a bridge is designed and constructed, much of its eventual durability and longevity has been determined. Assessments of bridge durability performance were made based on data available in the literature along with a subset of the data available in the historical bridge records of the Alabama Department of Transportation. From these reviews it was determined that bridges in Alabama are currently providing service lives of approximately 55–60 years. A recent Federal Highway Administration edict that main artery highway bridges be designed for 75 year service life means that Alabama must improve the durability performance of its bridges. Improvements can best be made at the planning, structural design, and material selection stages, that is, in the design phase. Primary areas of focus in which to make changes and improvements can best be pinpointed by looking at durability performance of individual bridge subcomponents.