Investigation of carbon black nanoparticle modified cementitious composites for sensing dynamic vibro-acousto signals

Abstract

Current application of intrinsic piezoresistivity of cementitious materials filled with nano conductive substances is limited in sensing quasi-static signals featuring low-frequency and high-amplitude. Its self-sensing capacity for low-amplitude and high-frequency vibro-acousto signals is not fully investigated. In this study, different doses of carbon black nanoparticles (CBN) are added in cementitious materials and their conductivity is measured to find the percolation zone where the tunnelling effect dominates the conduction mechanism, followed by the characterization of their piezoresistivity. Consequently, impact forces and crack-related energy release, which generate dynamic signals in the range of vibrational and acoustic frequencies, are individually utilized to test the behaviour of such materials for sensing dynamic vibro-acousto signals. The results show that CBN-modified cementitious composites which show excellent piezoresistivity behaviour are capable of locally self-sensing dynamic signals as sensors. Comparing with piezoelectrical sensors, the developed sensor shows higher sensitivity to crack initiation.