Piezoresistive behavior of mortars loaded with graphene and carbon fibers for the development of self-sensing composites

Structural monitoring systems are gaining increasing interest in the field of civil engineering research, due to the recent commitment for the preservation of building heritage, for the saving of resources and for an eco-friendly construction industry. Recent researches show that the addition of conductive fillers and fibers within cement materials could originate cement-composites able to diagnose their own state of strain and tension, measuring the variation of their electrical characteristics (resistance). In this work, resistivity and piezoresistivity of mortars complemented with Graphene Nanoplatelets (GNP), and Carbon Fibers (CF) were evaluated. The variations in electrical resistivity as a function of strain were analyzed under cyclic uniaxial compression of the mortars samples. The results showed a high piezoresistivity behavior of the mortars with an optimal dispersion of GNP and CF, with a quite reversible relation between Fractional Change in Resistivity (FCR) and compressive strain.