Fatigue of Orthotropic Steel Decks

Experimental investigations reported on the fatigue behavior of orthotropic steel bridge decks have been rather limited. Results of fatigue tests on steel orthotropic decks with both conventional and biserrated trapezoidal ribs are presented. In the first phase, tests on two types of deck to rib plate welded connections unflanged and flanged ribs, and on two types of rib splices butt joint and diaphragm splices reveal that the unflanged rib to deck plate connection and the butt joint rib splice exhibit satisfactory fatigue strength. Results of the second phase, involving decks with biserrated ribs subject to AASHO wheel loads, indicate that an optimum serration radius can be determined, and that fatigue cracks developed at lower serration corners do not result in the total collapse of the deck.