Multifunctional composite rebars for distributed structural health monitoring of concrete structures

Structural health monitoring (SHM) of reinforced concrete structures is a rapidly developing field with significant advancements over the last decade. Most of the existing SHM systems rely on a large number of point sensors attached to or embedded inside the structures. The sensor network should be densely distributed on the structure or around the potential damage areas for an acceptable damage detection performance. Apparently, this is not an optimal solution for an effective cost. On the other hand, issues such as securing a reliable power supply, cable connections and maintenance costs have remained a major challenge for current distributed SHM systems. To cope with these challenges, we propose a novel concept of multifunctional composite reinforcement rebars with sensing and energy harvesting functionalities for reinforced concrete structures. We develop multifunctional rebars via introducing a triboelectric nanogenerator (TENG) technology into the fabrication process of fiber reinforced polymer (FRP) rebars. The developed rebars with built-in TENG mechanism serve both as nanogenerators and distributed sensing systems under external mechanical vibrations. We perform experiential studies to verify the electrical and mechanical performance of the developed self-powering and selfsensing composite rebars.