Utilization of carbon nanotubes (CNTs) in concrete for structural health monitoring (SHM) purposes: A review

Carbon nanotubes (CNT) as a functional filler can increase the electrical conductivity property of concrete and thus provide intrinsic self-sensing properties with no need for external sensors to monitor the behavior of concrete infrastructure and structures containing CNT. CNT-cement composites also improve mechanical strength and have higher energy absorption capacity. The sensitivity of their electrical conductivity to external physical parameters, such as strain, stress, load, temperature, displacement, and pressure, makes them suitable for structural health monitoring (SHM) applications. This paper presents a comprehensive review of the CNT properties, fabrication process, composition, and sensing characteristics as well as challenges for applying CNT concrete as part of a self-sensing structure. Furthermore, the self-healing property of CNT, as an integral feature of future smart concrete infrastructure is discussed.