Graphene nanoplatelet/polypropylene pellets in cement-based composites: Mechanical, piezoresistive and microstructural properties

Graphene nanoplatelet-reinforced polypropylene is considered a promising conductive polymer -based additive to provide unique features to cementitious composites. This study comprehensively investigated the collective effects of graphene and polypropylene in the form of graphene nanoplatelet/polypropylene pellets (GrPp). Adding GrPp increased the flexural strength of the cementitious composites due to its high tensile strength. Moreover, the GrPp-enhanced cementitious composites show a high piezoresistive absolute maximum fractional change in electrical resistivity (FCR) of 96.50 %, stress sensitivity of 4.13 %/MPa, and repeatability of 90.81 % with the addition of 2-3.5 wt% GrPp on average. Furthermore, adding GrPp improved the piezoresistive behavior by forming a conductive path and increasing the deformability of the cementitious composites. These findings demonstrate that Gr-reinforced Pp pellets present an economical and efficient way to develop piezoresistive stress sensors for smart cement -based composites.