Experimental and Numerical Study of Transversal Flexural Behavior on Steel Ultrahigh-Toughness Cementitious Composite Bridge Decks

Currently, the composite bridge deck (CBD) system with ultrahigh-toughness cementitious composite (UHTCC) is understood to possess improved ductility and to resist cracking. To provide recommendations for designing this structural system in engineering practice, the flexural behavior in the transversal direction of steel-UHTCC CBDs was investigated using experimental and numerical analyses. Two steel-UHTCC CBDs with plate and U-ribs, respectively, were designed to obtain experimental data, including the failure mode, load-deflection curves, slippage development, and strain distribution. Then, finite-element (FE) models were established using ABAQUS software and validated against the test results. Eleven FE examples were designed for detailed parametric analysis of the stress on the steel plate in the steel-UHTCC CBD, with the design parameters mainly including the spacing between adjacent longitudinal ribs, the thickness of the UHTCC slab, and different working conditions and rib types. The experimental and simulated results illustrated the significant effect of using the UHTCC layer on improving the toughness and durability of the CBD structure, with the local effect greatly influenced by the longitudinal rib spacings. Finally, the transition condition between global and local failure modes of the steel-UHTCC CBDs, considering different longitudinal rib spacings, was studied, and a design scheme for obtaining the transition point is proposed to provide design suggestions.