Probabilistic life cycle analysis of alternative reinforcement products in the design of concrete structures - Phase One: Laboratory Durability Testing

混凝土结构设计中替代加固产品的概率生命周期分析 - 第一阶段：实验室耐久性测试

• 批准号: 514608-2017
• 负责人: ElHacha, Raafat
• 金额: $ 1.82万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Engage Grants Program
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=640542
• 关键词: Probabilistic; life; cycle; analysis; alternative

In Canada, bridges are exposed to harsh weather conditions. Such conditions result not only in deterioration ofthe concrete but mainly lead to corrosion of the steel rebar. Deterioration of aging bridge structures represents agrowing issue. Significant part of the issue is due to corrosion of the internal reinforcement. In Canadianenvironment, the rate of corrosion of the internal reinforcement in bridge structures is a function of severalparameters such as temperature, i.e., cycles of freezing and thawing, level of humidity and direct exposure towater, presence of de-icing salts, sustained and repetitive loads, and time. Due these factors, concrete loses itsability to protect the internal reinforcement. Unprotected reinforcement starts to corrode sooner thananticipated and, therefore, reduces the bridge service life. To avoid shortening of the service life, and safe costof maintenance, several types of advanced corrosion resistant reinforcing materials have been developed.In this research, performance and durability testing is proposed on several types of corrosion resistantreinforcing rebars including Fibre Reinforced Polymer (FRP) (Glass FRP, Carbon FRP and Basalt FRP),Martensitic Micro-composite Formable Steel (MMFX), and Stainless steel, in addition to the conventionaluncoated steel for comparison purposes. The reinforcing bars will be embedded in concrete specimensrepresenting a bridge parapet. These reinforced concrete specimens will be exposed to severe weatherconditions including spraying water and cycles of freezing and thawing then tested for ultimate capacity afterthe exposure. The study will evaluate material performance in terms of strength, durability, section loss of therebar, ductility, and cracking patterns to not only establish reference guidelines for the industry but mainlybroaden the fundamental knowledge about the behavioral patterns of selected materials in harsh environments.It is expected that the different types of rebars will influence the response of the concrete beams when loaded.As an outcome of the study, a report will be prepared summarizing how the application of the selectedmaterials can extend the service life and reduce the maintenance cost of structures exposed to harsh weather.

在加拿大，桥梁暴露在恶劣的天气条件下。这种情况不仅导致混凝土的劣化，而且主要导致钢筋的腐蚀。老化桥梁结构的劣化是日益严重的问题。问题的很大一部分是由于内部钢筋的腐蚀。在潮湿环境中，桥梁结构内部钢筋的腐蚀速率是温度等参数的函数，即，冻融循环、湿度水平和直接暴露于水、除冰盐的存在、持续和重复载荷以及时间。由于这些因素，混凝土失去了保护内部钢筋的能力。未加保护的钢筋开始腐蚀的速度比预期的要快，因此会缩短桥梁的使用寿命。为了避免钢筋使用寿命的缩短和安全的维修费用，人们开发了几种先进的耐腐蚀钢筋材料，本研究提出了几种耐腐蚀钢筋的性能和耐久性试验，其中包括纤维增强聚合物（FRP）。（玻璃纤维增强塑料、碳纤维增强塑料和玄武岩纤维增强塑料）、马氏体微复合材料可成形钢（MMFX）和不锈钢，以及用于比较目的的传统无涂层钢。钢筋将被嵌入混凝土护栏中。这些钢筋混凝土试件将暴露在恶劣的气候条件下，包括喷水和冻融循环，然后测试暴露后的极限承载力。这项研究将从强度、耐久性、钢筋截面损失、延性和开裂模式等方面评估材料性能，不仅为行业建立参考指南，而且主要拓宽了有关所选材料在恶劣环境下行为模式的基本知识。预计不同类型的钢筋将影响混凝土梁在加载时的响应。作为研究结果，我们会撰写一份报告，总结如何应用选定的材料，以延长建筑物的使用寿命，并减少在恶劣天气下的维修费用。