Aluminum Decks

Aluminum deck panels are briefly discussed in Article 9.8.4 of the AASHTO LRFD (7th Edition, 2014), as orthotropic aluminum deck panels. These deck panels consist of a deck plate stiffened and supported by rib extrusions, where the ribs are either parallel or perpendicular to the direction of traffic. An example of a rib extrusion is shown in Figure 18. The aluminum deck panel can be fabricated by shop welding individual extrusions together at their top and bottom flanges, as shown in Figure 19. A thin epoxy-type wearing surface is typically installed over the deck panel, but is not to be considered part of the structural deck system. The chosen wearing surface must be capable of providing sufficient skid resistance. The reader can refer to analytical and experimental investigations of aluminum deck panels that have been reported on in the literature (see references (23) and (24)).

Aluminum deck panels are to be designed to meet the requirements of Section 7 of the AASHTO LRFD (7th Edition, 2014) which pertains to aluminum structures. All applicable limit states should be considered in the design of the aluminum deck panels. Particular attention should be given to the fatigue limit state, and details should satisfy the provisions of Article 7.6, as well as the connection requirements associated with dissimilar materials if applicable. Furthermore, the longitudinal ribs, including the effective width of deck plate should be investigated for stability as individual beam-columns, assumed as simply supported at the transverse beams.

Similar to FRP deck panels, aluminum deck panels offer a lightweight alternative to conventional reinforced concrete bridge decks, making them ideal candidates for consideration in deck replacement projects where the live load capacity may be an issue. However, much like FRP deck panels, the use of aluminum deck panels is limited due to high initial costs and unfamiliarity with the deck system.