正交异性钢-RPC组合桥面板弯拉强度的实验研究

Research on Bending Tensile Strength for Composite Bridge Deck System Composed of Orthotropic Steel Deck and Thin RPC Topping

正交异性钢桥面一直面临疲劳开裂和铺装损坏的严重问题.为了改善桥面板受力状态,提出了一种新型的正交异性钢板薄层活性粉末混凝土(RPC)组合桥面结构体系.通过纵向足尺节段实验和横向受弯实验,表明新型组合桥面体系的抗弯拉强度远大于设计荷载下的拉应力,而重量与传统铺装持平.横向受弯实验结果证明,截面配筋率和截面有效高度对组合桥面结构抗弯拉强度影响很大,截面配筋率提高一倍和两倍,RPC的抗弯拉强度分别提高15%和40%.同样,截面有效高度增大20%,不同截面配筋率下RPC的抗弯拉强度提高30%～50%.因此,提高截面配筋率或截面有效高度能大幅降低组合桥面结构开裂破坏的风险.

Fatigue cracking in bridge deck and damage with asphalt pavement are severe issues to orthotropic steel bridge plates. In terms of the concept of the amelioration of the stress condition of the pavement, an innovative com- posite bridge deck system composed of orthotropic steel decks and a Reactive Powder Concrete （RPC） layer was pro- posed. The longitudinal partition test and lateral bending tests clearly illustrate that the bending tensile strength of this composite deck structure considerably exceeds the design stress, and its weight is approximately equal to those of the traditional pavement. Furthermore, the results of lateral bending tests adequately demonstrate that the bending strength of this new system is dependent on the reinforcement ratio and the effective height of the section. As the re- inforcement ratio is doubled and tripled, the bending strength is enhanced by 15 and 40 percent respectively. Similarly, the bending tensile strength increases by 30 to 50 percent on various reinforcement ratios when the effective sectional height is climbed by 20 percent. Consequently, the risk of crack or damage during bridge operation period will shrink substantially as the improvement of reinforcement ratios and the effective height of the section.