Self-sensing cementitious composite sensor with integrated steel fiber and carbonaceous powder for real-time application in large-scale infrastructures

The research focuses to develop and apply a self-sensing cementitious composite sensor (SCS) employing hybrid steel fiber_graphite powder (SF_GP) and steel fiber_activated charcoal (SF_AC) as an alternative for conventional sensors in structural health monitoring (SHM). The research examines the compressive strength, resistivity, piezoresistivity, and stress sensitivity, that influence the development of SCS. In addition, the SCS is embedded in critical zones of the large-scale beam and the column to monitor their deformations. The results show that the addition of SF_GP increases the compressive strength of the SCS to 48.27 MPa because of the post-cracking ductility of SF and decreases the resistivity to 4450 Ωcm due to the development of continuous conductive channels by SF and GP. The SCS integrated with SF_GP and SF_AC decreased the fractional change in resistivity (FCR) by 2% and 1%, respectively. The SCS composed of SF_GP embedded in the beam detected the deflection of the beam with 98.6% accuracy. The SCS comprised of SF_AC is 99.8% associated with column deformation. Thus, the developed SCS made of SF and powdered conductive elements enhances electromechanical properties and replaces sensors for having remarkable application in SHM.