Assessment of Bonding Conditions Between RC Structures and Advanced Composite Jackets

使用先进的复合材料（碳基或玻纤基）加固、改造和修复建筑和桥梁的结构性能得到了很好的证明，这种结构的数量正在迅速增加。然而，在钢筋混凝土（RC）结构和复合材料之间的粘合界面中，粘合质量差，特别是空洞，会显著降低复合材料可以获得的结构完整性。为了解决这一问题，本研究将开发一种电磁成像技术，用于评估混凝土与复合材料之间界面的粘结状况。一旦检测到空洞，在将复合材料应用于结构时，可以通过注入粘合剂环氧树脂来纠正它们。本研究的研究人员已经完成了一项初步研究，包括EM图像重建算法的开发和仿真，这不仅证明了所提出的技术在检测键合界面中的空隙方面的强大潜力，而且为克服与空间分辨率和评估速度相关的主要技术困难奠定了基础。主要研究任务包括：1)开发原型EM成像装置；2)进一步开发EM成像重建算法；3)通过对具有良好粘结和不良粘结界面的复合材料护套包裹的桥柱进行实验室测试来验证所开发的EM成像技术；4)对使用先进复合材料加固和改造的桥梁和建筑物进行现场测试，以验证所开发的EM成像技术的有效性。******* 9812856feng使用先进的复合材料（碳或玻璃纤维基）加固、改造和修复建筑和桥梁的结构性能得到了很好的证明，这种结构的数量正在迅速增加。然而，在钢筋混凝土（RC）结构和复合材料之间的粘合界面中，粘合质量差，特别是空洞，会显著降低复合材料可以获得的结构完整性。为了解决这一问题，本研究将开发一种电磁成像技术，用于评估混凝土与复合材料之间界面的粘结状况。一旦检测到空洞，在将复合材料应用于结构时，可以通过注入粘合剂环氧树脂来纠正它们。本研究的研究人员已经完成了一项初步研究，包括EM图像重建算法的开发和仿真，这不仅证明了所提出的技术在检测键合界面中的空隙方面的强大潜力，而且为克服与空间分辨率和评估速度相关的主要技术困难奠定了基础。主要研究任务包括：1)开发原型EM成像装置；2)进一步开发EM成像重建算法；3)通过对具有良好粘结和不良粘结界面的复合材料护套包裹的桥柱进行实验室测试来验证所开发的EM成像技术；4)对使用先进复合材料加固和改造的桥梁和建筑物进行现场测试，以验证所开发的EM成像技术的有效性。****

***9812856FengThe enhanced structural performance of buildings and bridges strengthened,retrofitted and rehabilitated with advanced composite (carbon or glassfiber-based) materials has been well demonstrated and the number of suchstructures is rapidly increasing. However, poor bonding quality,particularly voids, in the adhesive interfaces between the reinforcedconcrete (RC) structure and the composite material can significantlydegrade the structural integrity that could otherwise be obtainable by thecomposite material. In order to solve this problem, this research willdevelop an electromagnetic (EM) imaging technology for assessing thebonding condition in the interface between concrete and a compositematerial. Once the voids are detected, they can be corrected by injectingadhesive epoxy at the time when the composite material is applied on thestructure.The investigators of this research have completed a preliminary studyincluding development of EM image reconstruction algorithms and simulation,which not only demonstrated the strong potential of the proposed technologyin detecting voids in the bonding interface, but also established a basisfor overcoming the major technical difficulties associated with the spatialresolution and speed of assessment in this three-year study. The majorresearch tasks include: 1) development of a prototype EM imaging device,2) further development of the EM imaging reconstruction algorithms, 3)verification of the developed EM imaging technology by laboratory testingon the bridge columns wrapped with composite jackets with well bonded andpoorly bonded interfaces, and 4) field tests for the effectiveness of thedeveloped EM imaging technology on bridges and buildings strengthened andretrofitted with advanced composite materials.*******9812856FengThe enhanced structural performance of buildings and bridges strengthened,retrofitted and rehabilitated with advanced composite (carbon or glassfiber-based) materials has been well demonstrated and the number of suchstructures is rapidly increasing. However, poor bonding quality,particularly voids, in the adhesive interfaces between the reinforcedconcrete (RC) structure and the composite material can significantlydegrade the structural integrity that could otherwise be obtainable by thecomposite material. In order to solve this problem, this research willdevelop an electromagnetic (EM) imaging technology for assessing thebonding condition in the interface between concrete and a compositematerial. Once the voids are detected, they can be corrected by injectingadhesive epoxy at the time when the composite material is applied on thestructure.The investigators of this research have completed a preliminary studyincluding development of EM image reconstruction algorithms and simulation,which not only demonstrated the strong potential of the proposed technologyin detecting voids in the bonding interface, but also established a basisfor overcoming the major technical difficulties associated with the spatialresolution and speed of assessment in this three-year study. The majorresearch tasks include: 1) development of a prototype EM imaging device,2) further development of the EM imaging reconstruction algorithms, 3)verification of the developed EM imaging technology by laboratory testingon the bridge columns wrapped with composite jackets with well bonded andpoorly bonded interfaces, and 4) field tests for the effectiveness of thedeveloped EM imaging technology on bridges and buildings strengthened andretrofitted with advanced composite materials.****