Analytical and Experimental Evaluation of an Aluminum Bridge Deck Panel.

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Deck deterioration is responsible for the majority of deficient bridge ratings in the United States (Sotiropoulos & GangaRao, 1993). Subject to dynamic loading, cyclic loading, and occasional overloading, bridge decks are the most severely stressed elements in a bridge (Wolchuk, 1987). Combined with the stresses induced by environmental effects such as temperature variations, moisture variations, and freeze-thaw cycles, it is easy to see why the Federal Highway Administration estimates that 7,000 bridge decks are in need of immediate replacement (The Aluminum Association, 1996). Deck deterioration is accelerated by corrosion problems. De-icing salts applied to bridge decks eventually penetrate the concrete and corrode the reinforcing steel. The corroding steel, in turn, causes the deck to crack, spall, and delaminate. This damaged concrete is more susceptible to additional permeation of harmful chemicals, thus accelerating the process of deck deterioration. Steel decks, although not as common as concrete, are also prone to corrosion. Many potential solutions have evolved in the hopes of limiting corrosion damage. Less permeable concrete, cathodic protection systems, and protective coatings are just a few of the methods being examined. Another approach to eliminating this corrosion problem is the use of alternative materials such as aluminum. Reynolds Metals Company (Reynolds) believes that aluminum components can provide a long lasting, durable infrastructure. Reynolds has invested considerable resources to develop their proprietary aluminum deck system. Once these decks were developed, Reynolds approached several state departments of transportation in hopes of securing projects to showcase their new system. Interested in the potential for long-term savings, the Virginia Department of Transportation agreed to employ the deck system in two projects. A single-span bridge located on U.S. Route 58 was chosen for the first project. Using the aluminum deck in a new superstructure, the bridge was widened by 1.83 m (6 ft) to remove it from the functionally obsolete list (New Aluminum Decks, 1996). Originally, the second project that was planned was supposed to involve a continuous span bridge on Virginia's Smart Highway, the state test bed for intelligent transportation systems and materials. However, recent complications with fabrication of the second deck have delayed initiation of the second project. Since this aluminum bridge venture involved new technologies, it was classified as an experimental project and required a thorough evaluation. Using Federal Highway Administration sponsorship, the Virginia Transportation Research Council initiated a three-phase study of the Reynolds deck system. The first phase of the study focused on evaluating the static response of a 2.74 m x 3.66 m (9 ft x 12 ft) deck panel. Both experimental and analytical response information were used in the evaluation process. Experimental response data was obtained from seven service-load tests and two ultimate-load tests conducted in the fall of 1996 at the Turner-Fairbank Structural Laboratory. Analytical response information was generated from finite element models developed to accurately represent the deck panel. The evaluation of the deck panel for service loads and the response information from laboratory tests and finite element models are presented in this report. Evaluation of the panels based on ultimate load tests will be described in a subsequent report.

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