Investigation of the effectiveness of graphene/polyvinyl alcohol on the mechanical and electrical properties of cement composites

Abstract

Smart cement-based composites provide indispensable support for the intellectualization of a concrete structure. Graphene and its composites have been the focus of research in recent years. However, the application of graphene in smart cement-based concrete is still rare, which is probably due to the poor compatibility between graphene and the cement matrix, the high preparation cost of graphene and the complex construction process of the composites. Moreover, existing smart cement-based composites have poor ductility, so their self-sensing range of the ultimate tensile strain is much smaller than that of the compressive strain. In contrast, it is very important to monitor the tensile strain and detect cracks in concrete structures. Additionally, it is necessary to improve the ductility of smart cement-based composites. Therefore, in this study, a graphene/polyvinyl alcohol (PVA) dispersion is prepared by one-step liquid-shear exfoliation at a relatively low cost when compared to commercial graphene products; the dispersion can not only substitute for water but also can be directly used in the cement-based composite material for casting. The mechanical, electrical and piezoelectric properties of the as-prepared graphene/PVA hybrid modified cement with a low graphene content can be comparable with the cement materials using commercial graphene. Thus, graphene/PVA hybrid modified cement could be a potential candidate for structural health monitoring material.