A Wireless Embedded Sensor System to Monitor and Assess Corrosion in the Tendons of Prestressed Concrete Girders

中国的结构混凝土桥梁的民用交通基础设施正在老化和恶化--这主要是由于钢筋筋的腐蚀，这些钢筋筋赋予了这些结构的强度。目前的估计是，美国现有腐蚀结构的检查、修复和更换的总成本为2100亿美元。评估钢筋的状况仍然主要基于定性的目测和预期的设计寿命，因为钢筋通常埋在1到2英寸或更深的混凝土下面。一个由三名研究人员组成的多学科团队，在无损评估(NDE)、无线通信和结构建模领域具有专业知识，已与所在州交通部的桥梁设计师和管理人员合作，开发了一种无线嵌入式传感器系统，用于检测预应力混凝土梁中的钢筋腐蚀。该项目的成果有可能提供有关钢筋内部状况以及新材料和修复方法的有效性的先进、准确的信息，每年可为国家节省数十亿美元。该研究计划包括三个推进领域和一个示范项目。在推进器1中，将开发一种使用嵌入式传感器的腐蚀检测和监测方法。推力2号将内部传感器与无线系统集成在一起，以适应混凝土大梁恶劣的嵌入式环境。推力3涉及开发一种软件程序，用于将嵌入的传感器数据与重大结构特征的变化相关联。最后，与伊利诺伊州交通部合作，嵌入式传感器系统将在制造过程中安装在预应力梁中，以便在更长的一段时间内进行现场测量，以验证这种新的嵌入式传感器系统的有效性。这项研究将说明整合几个领域的技术和专业知识在解决复杂的信息流问题方面的重要性，不仅对于结构健康监测和评估界，而且对于任何类型的传感器数据和决策之间的联系没有明确定义的其他领域。该项目中实施的开发方法也可以应用于其他问题，以生产向资源管理人员提供具有成本效益和有用信息的传感器系统。

The nation's civil transportation infrastructure of structural concrete bridges is aging and deteriorating - principally as a result of the corrosion of the steel reinforcement tendons that give these structures their strength. Current estimates place the total cost of inspection, rehabilitation, and replacement of existing corroded structures in the US at $210 billion. Assessing the condition of the steel reinforcement is still based primarily on qualitative visual inspections and anticipated design lives, since the steel is typically buried beneath 1 to 2 inches or more of concrete. A multi-disciplinary team of three researchers, with expertise in the areas of non-destructive evaluation (NDE), wireless communication, and structural modeling have joined with bridge designers and managers from their state department of transportation to develop a wireless embedded sensor system to examine corrosion of tendons in prestressed concrete girders. The results of this project have the potential to deliver advanced, accurate information about the internal condition of steel reinforcement as well as the efficacy of new materials and rehabilitation methods and could save the nation billions of dollars annually. The research plan consists of three thrust areas and a demonstration project. In Thrust 1, a corrosion detection and monitoring method will be developed that uses embedded sensors. Thrust 2 will integrate the internal sensors with wireless systems for the harsh, embedded environment of a concrete girder. Thrust 3 involves the development of a software program for relating embedded sensor data to changes in significant structural characteristics. Finally, in cooperation with the Illinois Department of Transportation, the embedded sensor system will be installed in a prestressed girder during fabrication so that in-field measurements can be taken over an extended period of time to validate the effectiveness of this new embedded sensor system. This research will illustrate the importance of integrating technologies and expertise from several fields in solving complex information flow problems, not only for the structural health-monitoring and assessment community, but also for other areas where the link between any kind of sensor data and decision-making is not well-defined. The development methodology implemented in this project can also be applied to other problems to produce sensor systems that provide cost-effective and useful information to resource managers.