Nondestructive Evaluation of FRP-Confined Concrete Using Microwave

玻璃钢约束混凝土的微波无损评价

• 批准号: 0324607
• 负责人: Oral Buyukozturk
• 金额: --
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-11-15 至 2008-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0324607&HistoricalAwards=false
• 关键词: Nondestructive; Evaluation; FRP; Confined; Concrete

Nondestructive Evaluation of FRP-Confined Concrete Using Microwave, CMS project 0324607PI: Oral Buyukozturk, MITFiber-reinforced plastic (FRP) composite jacketing systems have emerged as an alternative to traditionalconstruction, strengthening, and repair of reinforced concrete columns and bridge piers. A large numberof projects, both public and private, have gone after such technology and escalating deployment has beenexpected, especially in seismically active regions. Yet, an efficient and effective structural evaluationtechnology that is capable of assessing the concrete conditions inside the FRP jacketing systems islacking. It is clear that a reliable concrete imaging technology needs to be soon developed to catch upwith the surging industrial applications.The objective of this research is to develop and apply effective nondestructive evaluation (NDE) imagingtechniques to visualize and quantify damages such as FRP delaminations and concrete cracking andcrumbling in FRP-confined reinforced concrete members using wideband radar. To achieve the objective,theoretical models and design of image reconstruction algorithms will be developed for automaticprocessing of measured data in parallel with experimental studies of physical models both in laboratoryand field settings. A database of electromagnetic (EM) properties of various FRP, concrete, and FRP-concrete hybrid media will also be established to facilitate these developments. The research plan consistsof four major tasks: (a) Numerical modeling of wave propagation and scattering, (b) Determination ofdielectric properties of FRP, concrete, and FRP-concrete hybrid media, (c) Physical radar measurement,and (d) Signal processing and image reconstruction. The four tasks are closely knitted in nature and willbe conducted in an iterative and evolutionary fashion.For this proposed work, a novel data focusing methodology using wideband radar is proposed for aneffective detection of various damage mechanisms associated with the FRP bonded and confinedreinforced concrete systems. Owing to the novelty of using wideband radar to detect damages of FRPconfined concrete, a one-year exploratory study has been underway since September 2002 under the NSF Small Grant Exploratory Research (SGER) program to initially demonstrate the potential capability of the herein proposed methodology. From this exploratory work thus far, promising results have been obtained. With this present proposal, funding is sought to fully develop the methodology and perform acomprehensive theoretical/experimental research toward achieving the objectives as stated above.Considering its non-traditional civil engineering nature, this project will synthesize the knowledge andunderstanding that has been developed in the areas of structural engineering, material science, electricalengineering and computer science. This multidisciplinary research project will be performed withcollaboration of Department of Civil and Environmental Engineering, Department of ElectricalEngineering and Computer Science, Research Laboratory of Electronics, and Lincoln Laboratory of theMassachusetts Institute of Technology.It is envisioned that the proposed work will significantly advance scientific knowledge in the areas of computer simulation, innovative imaging concepts, signal processing and image reconstruction, and laboratory methodologies dealing with radar measurements. Development of knowledge as a basis for manufacturing an effective equipment in this field will directly impact the profession, and benefit engineers, transportation infrastructure communities, and decision-making authorities worldwide. Application of the knowledge and technology developed will help ensure public safety against unanticipated failures of structural systems repaired or renewed using FRP composites. Developed knowledge and methodologies will be integrated into education via course curriculums and professional workshops. Every effort will be made to encourage female and minority student participation in the conduct of the proposed research.

使用微波对 FRP 约束混凝土进行无损评估，CMS 项目 0324607PI：Oral Buyukozturk，MIT 纤维增强塑料 (FRP) 复合护套系统已成为钢筋混凝土柱和桥墩传统施工、加固和修复的替代方案。许多公共和私人项目都在寻求此类技术，并且预计会不断升级部署，特别是在地震活跃地区。然而，缺乏一种能够评估 FRP 护套系统内部具体条件的高效结构评估技术。显然，需要尽快开发出可靠的混凝土成像技术，以赶上蓬勃发展的工业应用。本研究的目的是开发和应用有效的无损评估（NDE）成像技术，利用宽带雷达对 FRP 分层、混凝土开裂和破碎等损伤进行可视化和量化。为了实现这一目标，将开发图像重建算法的理论模型和设计，用于自动处理测量数据，同时在实验室和现场环境中对物理模型进行实验研究。还将建立各种玻璃钢、混凝土和玻璃钢-混凝土混合介质的电磁（EM）特性数据库，以促进这些发展。该研究计划包括四项主要任务：（a）波传播和散射的数值模拟，（b）确定FRP、混凝土和FRP-混凝土混合介质的介电性能，（c）物理雷达测量，以及（d）信号处理和图像重建。这四项任务本质上紧密相连，并将以迭代和进化的方式进行。对于这项拟议的工作，提出了一种使用宽带雷达的新型数据聚焦方法，用于有效检测与 FRP 粘合和约束钢筋混凝土系统相关的各种损伤机制。由于使用宽带雷达检测 FRP 约束混凝土损伤的新颖性，自 2002 年 9 月起，在 NSF 小额赠款探索性研究 (SGER) 计划下进行了为期一年的探索性研究，以初步证明本文提出的方法的潜在能力。迄今为止，这项探索性工作已经取得了可喜的成果。通过本提案，寻求资金来充分开发该方法并进行全面的理论/实验研究，以实现上述目标。考虑到其非传统土木工程性质，该项目将综合结构工程、材料科学、电气工程和计算机科学领域已发展的知识和理解。这个多学科研究项目将与麻省理工学院土木与环境工程系、电气工程与计算机科学系、电子研究实验室和林肯实验室合作进行。预计拟议的工作将显着推进计算机模拟、创新成像概念、信号处理和图像重建以及处理相关问题的实验室方法等领域的科学知识。 雷达测量。知识的发展作为制造该领域有效设备的基础将直接影响该行业，并使全世界的工程师、交通基础设施社区和决策机构受益。所开发的知识和技术的应用将有助于确保公共安全，防止使用 FRP 复合材料修复或更新的结构系统出现意外故障。开发的知识和方法将通过课程和专业研讨会融入教育中。我们将尽一切努力鼓励女性和少数族裔学生参与拟议研究的开展。