Flexural fatigue performance of flat steel plate-concrete composite bridge deck

The flat steel plate-concrete composite bridge deck (FSPCCD) is composed of a steel plate module and a concrete slab. The load bearing capacity, flexural stiffness, deformability, and construction efficiency of the bridge deck are significantly improved. In this paper, a total of 5 full-scale FSPCCD specimens were first tested to failure under constant-amplitude fatigue load in sagging moment. The investigated parameters were the type of shear connector and the amplitude of fatigue load. All the specimens exhibited fatigue failure, characterized by significant cracking in both the concrete and the steel plate, followed by concrete crushing. The crack of steel plate initiated at the stiffened region of the steel plate. Note that no fracture of steel bars or shear studs was observed, indicating that the fatigue strength of the FSPCCD investigated in this study was governed by the fatigue resistance of the steel plate. The degradation of stiffness under increasing load cycles was found to be minimal. Finally, existing methods for predicting fatigue strength were evaluated against the experimental results, based on which the prediction method for the fatigue strength of the FSPCCD was recommended.