Parametric Optimization Analysis on Flexural Performance of Steel–UHTCC Composite Bridge Decks

To investigate the influence of different structural design parameters on the flexural performance of steel–UHTCC composite bridge decks and to determine reasonable ranges for these parameters, a finite element model was developed based on a literature review and existing experimental studies. The numerical results were then validated against experimental data, confirming the reliability of the model. Subsequently, a parametric study was conducted using the validated model, systematically considering the effects of rib thickness, rib height, steel deck thickness, UHTCC layer thickness, and longitudinal reinforcement ratio on the flexural behavior of the composite bridge decks, and recommendations for appropriate parameter values were proposed. The results indicate that increasing rib thickness and rib height is relatively cost-effective for improving the flexural performance of steel–UHTCC composite bridge decks, whereas increasing steel deck thickness and UHTCC layer thickness is less efficient in enhancing flexural performance. In addition, the amount of longitudinal reinforcement has a negligible effect on both the load-bearing capacity and stiffness of the composite bridge decks.