Improvement of Bending Fatigue Test for Asphalt Surfacing on Orthotropic Steel Bridge Deck

In order to evaluate the fatigue performance for orthotropic steel bridge decks (OSBD) surfacing more scientifically and reasonably, one improved fatigue bending test for OSBD surfacing was developed based on the French "Laboratoire des Ponts et Chaussees" (LCPC) test. Besides, a better specimen preparation method was proposed based on the rolling compaction method. The loading force during testing was determined by building a three-dimensional finite element model of the entire bridge. In addition, a submodel technique was applied to enhance calculation accuracy. In order to verify the validation of this improved test, two types of deck surfacing mixtures: epoxy asphalt concrete (EAC) and high-strength asphalt concrete (HSAC) were tested, and the fatigue process of these two mixtures was recorded. During the fatigue test procedures, EAC surfacing can endure over 8 x 10(6) loading cycles and the fatigue life of HSAC surfacing was between 2 and 3 x 10(6) loading cycles. The EAC cracking process demonstrated brittle failure, while HSAC demonstrated ductile failure. These results reflected that the surfacing specimen fatigue performances during the laboratory test coincide with the practical OSBDs surfacing performance on an actual bridge. The improved bending fatigue test proved to be an effective way to reflect the OSBD surfacing mechanical response.