Recent research showed that ultrahigh-performance concrete (UHPC) and orthotropic steel bridge decks could be integrated to form steel-UHPC composite sections offering superior load-carrying capacity and fatigue resistance. This study investigates the effects of longitudinal stiffener types on the fatigue resistance of steel-UHPC composite sections. Three types of longitudinal stiffeners were compared, including U-ribs, bulb flat ribs, and plate ribs. Finite element analysis and full-scale fatigue tests were performed to investigate the load-carrying capacity and fatigue resistance of the composite bridge decks with different stiffeners. Besides, the proposed steel-UHPC composite bridge decks were compared with conventional orthotropic steel decks. The results show that steel box girders with bulb flat rib composite deck have reasonable fatigue resistance, construction efficiency, and economic benefits. This study is expected to promote the design and evaluation of economic steel-UHPC composite bridge decks to achieve higher mechanical performance and long-term durability.
Loading....