A comparative study between carbon nanotubes and carbon nanofibers as nanoinclusions in self-sensing concrete

Structural Health Monitoring is the automated process of damage detection and performance assessment aiming at providing reliable information regarding the integrity and the safety of a structure. Conventional measurement devices usually employed in structural health monitoring systems are affected by known drawbacks that limit their performance for health assessment, such as reduced durability against environmental actions, difficulty of access, high costs and low scalability. New nanomodified self-sensing materials may enable dense network sensing applications. Such materials are fabricated by integrating conductive nanoparticles into a building material, for instance a cementitious matrix. The self-sensing function is obtained by correlating the state of strain with appropriate material parameters, such as electrical resistance. This paper investigates and compares the smart properties of cement-based nanocomposite materials fabricated using carbon nanotubes and carbon nanofibers as conductive nanoinclusions. The work discusses the preparation procedures to obtain a homogeneous distribution of nanoparticles in the cementitious materials and the strain sensitivity of different nanocomposite specimens.