Liu The enhanced structural performance of buildings and bridges strengthened, retrofitted and rehabilitated with advanced composite (carbon or glass fiber-based) materials has been well demonstrated and the number of such structures is rapidly increasing. However, poor bonding quality, particularly voids, in the adhesive interfaces between the reinforced concrete (RC) structure and the composite material can significantly degrade the structural integrity that could otherwise be obtainable by the composite material. In order to solve this problem, this research will develop an electromagnetic (EM) imaging technology for assessing the bonding condition in the interface between concrete and a composite material. Once the voids are detected, they can be corrected by injecting adhesive epoxy at the time when the composite material is applied on the structure.
The investigators of this research have completed a preliminary study including development of EM image reconstruction algorithms and simulation, which not only demonstrated the strong potential of the proposed technology in detecting voids in the bonding interface, but also established a basis for overcoming the major technical difficulties associated with the spatial resolution and speed of assessment in this three-year study. The major research 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 testing on the bridge columns wrapped with composite jackets with well bonded and poorly bonded interfaces, and 4) field tests for the effectiveness of the developed EM imaging technology on bridges and buildings strengthened and retrofitted with advanced composite materials. ***
