Structural Bridge Deck Overlay (SBDO) involves applying 6 to 10 inches (150 to 200 mm) of normal weight, class AA, reinforced concrete directly to a bridge’s original slab. The overlay is designed to increase the deck elevation to an extent that standard highway resurfacing procedures can continue uninterrupted up the edges of the bridge. Otherwise, excavation along the bridge approaches or jacking of the superstructure is required to insure proper elevation.

Experimental static field tests were conducted on three different bridges: (1) Simply supported prestressed concrete I-girder bridge; (2) cast-in-place reinforced concrete continuous haunched girder bridge; and (3) cast-in-place reinforced concrete simple span bridge. Field tests were conducted prior to the concrete overlay process and following the application of the concrete overlay.

Based on the results obtained in this research study, a significant advantage is noted due to the additional deck thickness. The addition of the SBDO increases the load carrying capacity of the bridge in addition to providing a wider bridge deck and new and code compliant barrier walls.

Report Date


Report Number

KTC-06-05/FRT 81-82-97-1F

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