Fatigue Durability of Concrete Bridge Decks

混凝土桥面的疲劳耐久性

• 批准号: 9872357
• 负责人: Victor Li
• 金额: $ 39.01万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-01 至 2001-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9872357&HistoricalAwards=false
• 关键词: Fatigue; Durability; Concrete; Bridge; Decks

Victor Li, University of MichiganThe investigation addresses the fatigue durability of concrete bridge decks. Recent research suggests that the fatigue cracking can be a precursor to severe failure of concrete bridge docks. The fundmentals of fatigue damage and corresponding remedial action on bridge decks are currently poorly understood. This investigation focuses on basic understanding of fatigue durability of concrete bridge decks and on fatigue durability enhancement by the use of fiber reinforcement. fiber reinforcement is especially focused on because of the extensive documentation of fatigue resistance enhancement of fiber reinforced concrete (FRC) in laboratory. The mechanism of crack growth under fatigue loading, and aggregated and fiber bridging (across a concrete crack) response subjected to cyclic loading, are analyzed with a statistical/micromechanics based theoretical model. In addition, the degradation of the fiber/cement and aggregate/cement interface are expilicitly accounted for based on experimental observations.Four important consequences of this research are:1) Bridge deck slab design procedure against fatigue damage; 2) Fundamental understanding of the mechanisms governing fatigue failure of FRC; 3) Micromechanics based model for design of fatigue resistance FRC composites; and 4) Evaluation/repair procedure of brige decks using FRC. This research leads to mechanism based structural performance design forcing a tight connection between materials and structural engineering. The approach adopted is combination of experimental and theoretical work. Field data of bridge deck performance and laboratory data of fatigue specimens are emphasized. The nature of this reseach requires combined knowledge of bridge engineering as well as composite materials engineering.

Victor Li，密歇根大学这项研究涉及混凝土桥面的疲劳耐久性。 最近的研究表明，疲劳裂纹可能是混凝土桥墩严重失效的先兆。 目前人们对桥面疲劳损伤的基本原理和相应的补救措施知之甚少。 本研究的重点是对混凝土桥面疲劳耐久性的基本了解以及通过使用纤维增强材料增强疲劳耐久性。 由于实验室中关于纤维增强混凝土（FRC）抗疲劳性能增强的大量文献，纤维增强材料尤其受到关注。 使用基于统计/微观力学的理论模型分析了疲劳载荷下裂纹扩展的机制，以及循环载荷下聚合和纤维桥接（穿过混凝土裂纹）的响应。 此外，基于实验观察，纤维/水泥和骨料/水泥界面的退化得到了明确的解释。这项研究的四个重要结果是：1）桥面板抗疲劳损伤的设计程序； 2）对FRC疲劳失效机理有基本的了解； 3）基于微观力学的抗疲劳FRC复合材料设计模型； 4) 使用 FRC 的桥面评估/修复程序。 这项研究导致了基于机制的结构性能设计，迫使材料与结构工程之间紧密联系。 所采用的方法是实验和理论工作的结合。 强调了桥面性能的现场数据和疲劳试件的实验室数据。 这项研究的性质需要结合桥梁工程和复合材料工程的知识。