Short-term and long-term behaviour of GFRP bars and bends

2010年，全球钢铁腐蚀给经济造成的总损失估计为2.2万亿美元，约占全球GDP的3%(2010年)。作为这种破坏的一部分，混凝土结构中钢筋的腐蚀正在造成巨大的困难，因为在许多情况下，钢筋的恶化已经达到不安全的水平，维修费用已经上升到数十亿美元。在加拿大，两个明显的例子是最大城市多伦多和蒙特利尔的桥梁老化。在混凝土结构中替代钢筋最可行的方法是玻璃纤维增强聚合物(GFRP)。这项建议涉及在混凝土基础设施中使用玻璃钢作为内部钢筋。最近的短期试验工作表明，玻璃纤维增强混凝土构件具有良好的性能，但有关其长期性能的现有信息严重有限。该项目的目标是为使用100年或更长寿命的玻璃纤维增强结构制定合理的设计指南提供信息。混凝土结构中的钢筋在如此长的寿命内承受着持续的荷载。没有可靠的模型可以确定这些材料的失效时间。拟议的工作将研究不同水平持续荷载下的GFRP直筋和弯筋的这一问题，开发合理的模型和设计指南，以帮助我们建立可持续的基础设施。这项工作将与结构设计公司和玻璃钢制造商的专家合作进行。加拿大从这项工作中获得的其他好处将包括培训工程师，制定具体设计规范和手册的指导方针，以及在使用最先进的研究和新兴技术设计结构方面为加拿大公司和工程师提供全球竞争优势。

The total cost to the economy due to corrosion of steel worldwide in 2010 was estimated at USD $2.2 trillion which is about 3% of the world's GDP (Hays 2010). As part of this damage, corrosion of steel reinforcement in concrete structures is causing enormous hardships as deterioration has reached unsafe levels in many cases and repair costs have mounted to billions of dollars. Two obvious examples of this in Canada are the deteriorating bridges in the largest cities, Toronto and Montreal. A most feasible alternative to steel reinforcement in concrete structures is Glass Fiber Reinforcing Polymers (GFRP). This proposal relates to the use of GFRP as internal reinforcement in concrete infrastructure. The recent work on short term tests has shown excellent performance of GFRP-reinforced concrete components but available information on their long-term performance is seriously limited. The objective of this project is to generate information for developing rational design guidelines for GFRP-reinforced structures with life spans of 100 years or longer. Reinforcement in concrete structures is subjected to sustained loads for this long life. There are no dependable models that allow determination of time to failure for these materials. The proposed work will investigate this issue for GFRP straight bars and bent bars under various levels of sustained loads, develop rational models and design guidelines that can help us build sustainable infrastructure. This work will be carried out in collaboration with experts from structural design companies and GFRP manufacturers. Additional benefits for Canada from this work will include training of engineers, development of guidelines for concrete design codes and manuals as well as providing Canadian companies and engineers with a global competitive edge for the design of structures using the state-of-the-art research and emerging technologies.