Full-Scale Experimental Study on the Negative Flexural Behavior of Orthotropic Steel–Concrete Composite Bridge Deck

Abstract

The orthotropic steel–concrete composite deck, which consists of a concrete slab, an orthotropic steel plate, and shear connectors, has been applied for ameliorating the vehicle-induced fatigue damage on steel bridge decks. However, its static performance, especially its negative bending performance, has rarely been considered, despite its critical role in bridge durability and safety. Accordingly, negative bending tests on four full-scale composite deck specimens were carried out, in which the effects of steel-fiber-reinforced concrete (SFRC), the reinforcement ratio, and the shear connector type were investigated. The full-scale orthotropic steel plates of the test specimens were stiffened by large U-ribs, which were designed for construction convenience and cost reduction in applied engineering practice. The test results show that the bending stiffness of the composite deck was influenced by the reinforcement ratio and the shear connector type, and the load-carrying capacity was sensitive to the reinforcement ratio. The ultimate status was found to be dominated by buckling of the steel ribs. The use of SFRC had an obvious restraining effect on the crack-width development. Finally, the applicability of the current codes for the composite girder to the composite deck was verified by comparing the corresponding evaluations of reinforcement stress, bending stiffness, and crack feature with the test results.