关键词：桥梁；复合材料；力学性能；纤维增强复合材料
摘 要：The aging infrastructure in the United States puts a huge burden on bridge engineers and officials who strive to ensure public safety and meet community demands. Strengthening existing bridge structures instead of the more expensive replacement alternative has therefore been a more feasible choice in many cases, which led to large research efforts to develop new strengthening methods and explore the use of new materials. Fiber Reinforced Polymer (FRP) composites is considered one of the new materials that continue to grow and gain popularity for structural applications. Successful use of FRP relies on understanding its behavior and being able to confidently assess its properties. Characterizing material properties from random samples is important in order to better understand the behavior of FRP composites and implement them in design codes. Reliable and consistent methods of characterizing the material resistance are essential for the successful employment of any material. There are two popular statistical methods used for finding characteristic values for FRP composites: The first method is recommended by the American Concrete Institute (ACI) in publications produced by Committee 440 (Fiber-Reinforced Polymer Reinforcement), while the other is adopted by the American Society for Testing and Materials (ASTM International) in a standard for Evaluating Material Property Characteristic Values for Polymeric Composites for Civil Engineering Structural Applications, ASTM D7290. In this study, tensile and flexural tests are conducted on different FRP composite materials for the purpose of investigating the differences between these two methods. The experimental results were complemented with simulations of virtual specimens. The experimental and simulation results are then used to estimate the material properties following both characterization methods and to conduct comparisons between both methods.