Assessment of Bonding Conditions Between RC Structures and Advanced Composite Jackets

*9812856Feng用先进的复合材料(碳纤维或玻璃纤维)加固、翻新和修复的建筑物和桥梁的结构性能得到了很好的证明，而且这类结构的数量正在迅速增加。然而，钢筋混凝土(RC)结构和复合材料之间粘结界面的粘结质量差，特别是空洞，会显著降低复合材料本来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来评估混凝土与复合材料界面的粘结状况。本研究的研究人员已经完成了包括EM图像重建算法和仿真在内的初步研究，不仅展示了所提出的技术在检测粘接界面中空洞方面的强大潜力，而且为克服与评估的空间分辨率和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)开发电磁成像设备原型，2)进一步开发电磁成像重建算法，3)通过对界面粘结良好和粘结不良的复合材料夹套包裹的桥柱进行实验室测试来验证所开发的电磁成像技术，以及4)现场测试所开发的电磁成像技术在桥梁和用先进复合材料加固和加固的建筑物上的有效性。然而，钢筋混凝土(RC)结构和复合材料之间粘结界面的粘结质量差，特别是空洞，会显著降低复合材料本来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来评估混凝土与复合材料界面的粘结状况。本研究的研究人员已经完成了包括EM图像重建算法和仿真在内的初步研究，不仅展示了所提出的技术在检测粘接界面中空洞方面的强大潜力，而且为克服与评估的空间分辨率和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)开发电磁成像原型装置，2)进一步开发电磁成像重建算法，3)通过对界面粘结良好和粘结不良的复合材料夹套包裹的桥柱进行实验室测试来验证所开发的电磁成像技术，以及4)现场测试所开发的电磁成像技术在加固和加固先进复合材料的桥梁和建筑物上的有效性。

***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.****