Enhancement of mechanical and electrical properties of graphene/cement composite due to improved dispersion of graphene by addition of silica fume

Incorporation of graphene into cement-based materials has attracted extensive attention of many researchers. Achieving effective dispersion of graphene can contribute to improving the mechanical and other properties of the cement composite. In this study, the effects of silica fume content on compressive strength and electrical resistivity of the graphene/cement composite were investigated. The distribution of graphene and silica fume in cement matrix was observed by scanning electron microscopy (SEM) and the pore structure of the composite was analyzed by mercury intrusion porosimetry (MIP). Results revealed that silica fume was capable of facilitating the dispersion of graphene and increasing the interfacial strength between graphene and cement matrix. Moderate amount of silica fume can refine the pore structure of the cement paste. Incorporation of appropriate amount of silica fume can increase the compressive strength and reduce the electrical resistivity of the composite. However, the extra amount of silica fume had a negative effect on mechanical and electrical performances.