Long-term Degradation Mechanisms of Bond in Concrete Reinforced with Fiber Reinforced Polymers (FRP)

纤维增强聚合物增强混凝土中粘结的长期退化机理。布斯比，宾夕法尼亚州立大学查尔斯E。巴基斯，宾夕法尼亚州立大学修复国家日益恶化的基础设施需要开发和鉴定新材料。 纤维增强聚合物（FRP）是一种复合材料，最初通过基础研究开发，用于航空航天工业，在过去的二十年里，作为混凝土结构加固和修复以及其他建筑应用的合适材料，已得到人们的认可。 这些材料具有优异的强度重量比和耐腐蚀性。 然而，广泛采用这些材料来修复和加固桥梁，建筑物和其他结构需要了解环境退化的复杂过程，以便设计和建造足够耐用的材料。 用于混凝土加固的FRP可以是内部的，如钢筋，也可以是外部的，如粘合板或片材。 外部加固可用于修复或加固现有结构。 在所有情况下，材料在结构的使用寿命（通常为50-100年）内以及在持续的环境侵蚀（由于酸雨、冻融、热和湿度等）下与混凝土结合的能力，是其作为增强材料成功的关键。 拟议的研究将详细研究FRP加固，外部和内部，和混凝土之间的粘结特性，以及由于年龄，长期荷载和环境影响，这种粘结的退化过程。 该研究将调查在温带和热带气候的户外环境中老化的小型和中型标本，并进行加速环境调节。 这项研究将使这些材料的设计者能够更有信心地预测它们的耐用性。

Project AbstractLong-Term Degradation Mechanisms of Bond in Concrete Reinforced with Fiber Reinforced PolymersThomas E. Boothby, The Pennsylvania State UniversityCharles E. Bakis, The Pennsylvania State University The repair of the nation's deteriorating infrastructure requires the development and qualification of new materials. A class of composite materials known as fiber reinforced polymers (FRP), originally developed through basic research for use in the aerospace industry, have been gaining acceptance over the last two decades as suitable materials for reinforcement and repair of concrete structures, as well as for other construction applications. These materials have the advantage of exceptional strength-weight ratios and resistance to corrosion. However, the widespread adoption of these materials to repair and reinforcement of bridges, buildings, and other structures requires an understanding of the complex processes of environmental degradation, so that the material can be designed and built to be sufficiently durable. FRP's applied to reinforcement for concrete may be internal, such as reinforcing bars, or external, such as adhered plates or sheets. The external reinforcement may be used to repair or strengthen existing structures. In all cases, the ability of the material to bond to concrete over the lifetime of the structure (50-100 years, typically), and under continual environmental attack--due to acid rain, freeze-thaw, heat and humidity, etc.--is critical to its success as a reinforcing material. The proposed research will examine in detail the characteristics of bond between FRP reinforcing, both external and internal, and concrete, and the process of degradation of this bond due to age, long-term loading, and environmental effects. The research will investigate small and intermediate scale specimens aged in outdoor environments in temperate and tropical climates, and subjected to accelerated environmental conditioning. The research will enable designers of these materials to predict their durability with increased confidence.