Multifunctional self-sensing and ductile cementitious materials

Abstract This study focuses on the material design and electromechanical behavior of new multifunctional strain-hardening cementitious materials (MSCs) that integrate tensile ductility with self-sensing functionality. The material design was accomplished by tailoring the micro-scale electrical and mechanical parameters to achieve strongly coupled electromechanical behavior at macro-scale. Electrical impedance spectroscopy and equivalent circuit modeling were conducted to understand the effects of carbon black (CB) nanoparticles on material electrical microstructure. The results revealed that large signal-to-noise ratio and gauge factor can be achieved if the material contains sufficient amount of both partially conductive and conductive paths. Additionally, uniaxial tension, fracture toughness, and single crack opening tests explained the negative impact of CB nanoparticles on the material tensile strength and ductility, leading to material redesigning for improved mechanical behavior. Finally, the electromechanical response of the MSCs was studied under monotonic and cyclic loading, which demonstrated robust self-sensing capacity of MSCs during elastic, strain-hardening and tension-softening stages.