Durability of Fiber Reinforced Polymer Materials in Accelerated and Modeled Concrete Environments

9812745 porter本项目解决了关于纤维增强聚合物（FRP）材料的长期耐久性和加速老化特性的重要问题，该材料用于替代结构混凝土中的传统钢筋。这些类型的材料是MRI应用、海洋环境和许多其他民用和军事基础设施用途中取代钢筋和预应力筋的绝佳候选材料。这些材料显示出巨大的希望，因为它们是非金属的，因此人们认为它们通常不存在钢铁容易受到的腐蚀问题。这项研究的目标涉及额外的创新短期实验室测试，以便准确、可靠地预测FRP材料的长期性能。将检查使用嵌入乙烯基酯基质的长纤维玻璃股构建的FRP钢筋。本研究将研究FRP材料在暴露于混凝土环境和吸湿解吸循环时恶化和损伤过程的基本性质，这将用于研究创新方法来模拟这些过程的行为，并通过加速老化技术准确预测其长期行为。研究FRP加固在混凝土中的长期耐久性的步骤包括表征混凝土孔隙水的性质，并将此添加的模型与先前开发的模型进行比较。本研究的范围包括研究玻璃钢钢筋暴露在混凝土中常见环境条件下的影响。这涉及FRP筋的测试和分析，包括控制样本。其范围包括使试样在假定的老化条件下承受应力以及使试样不受应力。经过老化过程后，试样将在拉伸和弯曲中失效，以确定由于环境条件而导致的强度损失。

9812745PorterThis project addresses important issues regarding the long-term durability and accelerated aging characteritics of Fiber Reinforced Polymer (FRP) materials used for the replacement of conventional steel reinforcing in structural concrete. These type of materials are excellent candidates to replace steel reinforcing bars and prestressing tendons in MRI applications, marein environments, and many ofther civilian and military infrastructure uses. These materials show great promise because they are non-metallic and therefore are believed to be generally free of the corrosive problems to which steel has been suseptible. The objectives of the reserch involve additional innovative short-term laboratory tests that allow accurate, reliable prediction of long-term performance of FRP materials. FRP reinforcing bars constructed using long-fiber glass strands embedded in a vinyl ester matrix will be examined. This research will examine the fundamental nature of the deterioration and damage proceses in FRP materials when exposed to concrete environments and moisture absorption desorption cycles which will be used to look at innovative ways to model the behaviro of these processes and accurately predict the long-term behavior by accelerated aging techniques. Steps involve in studying the long-term durability of FRP reinforcement in concrete include characterizing the nature of concrete porewater and comparing this added model to previously developed models. The scope of this investigation involves studying the effects of FRP reinforcing bars exposed to common environmental conditions within concrete. This involves the test and analysis of FRP reinforcing bars, including control specimens. The scope includes subjecting specimens to stress under assumed aging conditions as well as unstressed specimens. Following subjection to the aging process, specimens will be failed in tension and flexure to determine the loss in strength due to the environmental conditions.