Experimental and analytical study on the flexural behavior of high‐strength <scp>ECC</scp> –steel composite bridge decks under negative moment

Abstract Steel–concrete composite bridge decks often exhibit limited crack control and ductility under negative moments. This study examines the flexural behavior of decks integrating an engineered cementitious composite (ECC) layer with an orthotropic steel plate. Four‐point bending tests were conducted on 24 specimens across 12 groups with varied reinforcement ratio, ECC thickness, rebar height, and stud spacing. All specimens showed flexural failure, with yielding of steel plates and rebars at ultimate load. The ECC layer effectively restricted crack widths below 0.2 mm at 0.8 Pu and exhibited high tensile ductility. Reinforcement ratio was the dominant factor influencing ultimate capacity, while thicker ECC and higher rebar placement enhanced performance. Reduced stud spacing slightly lowered strength. A simplified model predicted ultimate loads with maximum relative errors below 10% compared with the experimental results. The results confirm ECC–steel composite decks can significantly improve crack control and ductility for resilient bridge design.