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Static and fatigue test on lightweight UHPC-OSD composite bridge deck system subjected to hogging moment
Engineering Structures ( IF 5.5 ) Pub Date : 2021-05-06 , DOI: 10.1016/j.engstruct.2021.112459
Zheng Feng , Chuanxi Li , Jun He , Lu Ke , Zhijie Lei , George Vasdravellis

A cost-effective Lightweight Composite Bridge Deck (LCBD) system, including Orthotropic Steel Deck (OSD) and lightweight Ultra-High Performance Concrete (UHPC) layer is proposed to increase the stiffness and fatigue performance of conventional OSD. Static and fatigue tests on two full-scale strip models subjected to four-point bending were carried out. The static nominal cracking stress of the UHPC layer with reinforcement spacing of 80 mm is 24.59 MPa, while it increases to 35.68 MPa when the reinforcement spacing is reduced to half (40 mm); both values are far greater than the nominal stress of 12.7 MPa obtained in the prototype bridge. Increasing the reinforcement ratio can increase the bending stiffness of LCBD and decrease the tensile strain of the UHPC layer, while the change in range is relative slight. Furthermore, the flexural strength of UHPC and the reinforcement ratio are important factors affecting the fatigue life of the UHPC layer. When the reinforcement spacing increases from 40 mm to 80 mm, the fatigue life of the UHPC layer still satisfies related code requirements. Thus, for reduction in the engineering cost and construction complexity, the reinforcement spacing can be set as 80 mm. However, the application of the UHPC as the steel deck pavement, the rib-to-diaphragm welded joint is still prone to fatigue cracks. In addition, the existing S-N curves are hard to directly use for fatigue life prediction of the UHPC layer because of the great differences in the definition of stress level and evaluation index of failure in the fatigue test, which need to be modified in further studies.



中文翻译:

轻载下UHPC-OSD轻巧复合桥面板系统的静疲劳试验

为了提高传统OSD的刚度和疲劳性能,提出了一种经济有效的轻型复合桥面板(LCBD)系统,其中包括正交各向异性钢桥面板(OSD)和轻质超高性能混凝土(UHPC)层。在经受四点弯曲的两个全尺寸带钢模型上进行了静态和疲劳测试。钢筋间距为80 mm的UHPC层的静态标称开裂应力为24.59 MPa,而钢筋间距减小为一半(40 mm)时,静态标称开裂应力增加至35.68 MPa。这两个值都远大于原型桥中获得的12.7 MPa的标称应力。增加补强比可以增加LCBD的弯曲刚度并降低UHPC层的拉伸应变,而范围的变化相对较小。此外,UHPC的抗弯强度和增强比是影响UHPC层疲劳寿命的重要因素。当钢筋间距从40 mm增加到80 mm时,UHPC层的疲劳寿命仍满足相关规范要求。因此,为了降低工程成本和建造复杂性,可以将加强间距设定为80mm。但是,将UHPC用作钢甲板铺面时,肋骨到膜片的焊接缝仍然容易出现疲劳裂纹。另外,现有的 钢筋间距可以设置为80 mm。但是,将UHPC用作钢甲板铺面时,肋骨到膜片的焊接缝仍然容易出现疲劳裂纹。另外,现有的 钢筋间距可以设置为80 mm。但是,将UHPC用作钢甲板铺面时,肋骨到膜片的焊接缝仍然容易出现疲劳裂纹。另外,现有的SN曲线很难直接用于UHPC层的疲劳寿命预测,因为在疲劳测试中应力水平的定义和失效评估指标存在很大差异,需要进一步研究加以修改。

更新日期:2021-05-06
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