Durability Performances of Alabama Bridge Components and Subcomponents

Abstract

To gain a better understanding of how highway bridges in Alabama are performing in the area of durability/longevity, a review of the historical bridge records of the Alabama Department of Transportation was performed. Because of the large number of bridges, it was decided to select the subset of old bridges that were replaced during the 1980–93 period to evaluate their durability performance. Based on an analysis of this data subset, the most structurally deficient major component was the deck, followed by the substructure. The superstructure performed best. The worst performing subcomponents were the wearing surface, deck structure, curbs, expansion joints, abutment wings, and abutment backwall. The best performing subcomponents were the drains, rivet/bolt/weld connections, and piers or bents. The major reason for decks to fail functionally was the deck geometry. However, the structural condition of decks at the time of functional obsolescence was also near failure. The data indicated that simple span construction was superior to continuous span construction for enhancing durability. Simple spans excelled in performance in every component and subcomponent except for the curbs, columns of the bents or piers, and the alignment of members.