Orthotropic steel bridge deck system usually consists of an orthotropic steel deck and an asphalt overlay. Fatigue cracks of the orthotropic steel deck and premature damage of the asphalt overlay are frequently reported for such system. Engineering cementitious composites (ECC) was therefore proposed to replace the asphalt overlay to address the aforementioned issues. The current study presents an investigation on the transversal flexural behaviour of the ECC under bending forces. Influence of the bending force direction, cover thickness, the number of longitudinal reinforcement steel bars on the flexural performance was revealed. Responses with regard to the load-deflection curve, failure mode, the ultimate capacity, the cracking behaviour, the interfacial slip between ECC and steel deck and the nominal cracking stresses were analysed. The results showed that the load-deflection response under both negative and positive bending forces exhibits elastic stage, crack-developing stage and yield stage. Compared with the reinforcement ratio, cover thickness plays a more significant role on the flexural performances. When the cover thickness decreases from 35 mm to 25 mm, the peak load increases by 21%–25%. ECC maintains its feature of being ductile, with high tensile and compressive strain capacity in the composite slab. From the design point of view, reducing the cover thickness and increasing the reinforcement ratio can improve the ultimate load and cracking stress, and reduce the internal slip, strain and crack width of the composite slab. It is expected that the current study can provide basic knowledge to the design and application of the steel-ECC composite deck system.

正交异性钢桥面系统通常由正交异性钢桥面和沥青覆盖层组成。正交各向异性钢甲板的疲劳裂纹和沥青覆盖层的过早损坏经常被报道。因此，提出了工程水泥复合材料（ECC）来代替沥青覆盖层，以解决上述问题。当前的研究提出了在弯曲力作用下ECC的横向弯曲行为的研究。揭示了弯曲力方向，覆盖厚度，纵向钢筋数量对弯曲性能的影响。分析了关于载荷-挠度曲线，破坏模式，极限承载力，抗裂性能，ECC与钢甲板之间的界面滑移以及名义裂化应力的响应。结果表明，在负，正弯曲力作用下的载荷-挠度响应分别表现为弹性阶段，裂纹发展阶段和屈服阶段。与补强比相比，覆盖层厚度对弯曲性能的影响更大。当覆盖层厚度从35 mm减小到25 mm时，峰值载荷将增加21％–25％。ECC保持其延展性的特点，在复合板中具有高拉伸和压缩应变能力。从设计的角度来看，减小覆盖层厚度和增加配筋率可以改善极限载荷和开裂应力，并减小复合板的内部滑移，应变和裂缝宽度。预期当前的研究可以为钢-ECC复合甲板系统的设计和应用提供基础知识。