Feasibility study of smart functional strain-hardening cementitious composites: Self-sensing model and experimental performance

This work aims to conduct the feasibility study of a smart functional strain-hardening cementitious composites (SHCC) which integrates the strengthening function and self-sensing function with both experimental testing and theoretical model. Specifically, the smart functional SHCC were experimentally explored in terms of self-sensing property, electrical conductivity, microstructure, mechanical properties, and workability. The effects of test parameters such as the type of conductive material (i.e., multi-walled carbon nanotubes (MWCNT), carbon fibers, aluminum powder, and copper powder), conductive material dosage, and water-to-binder ratio were studied comprehensively. The results showed that smart functional SHCC fabricated with MWCNT and carbon fibers showed better self-sensing capacity, conductivity, mechanical properties and workability compared with those fabricated with copper powder and aluminum powder. More importantly, a bi-linear mechanical-electrical model considering fracture damage was proposed to predict the relationship between mechanical stress and electrical signal, and predict the crack initiation and internal damage. This work can promote a more comprehensive understanding for developing smart functional SHCC to achieve integrated self-sensing and strengthening functions.