Study of mechanical properties and microstructure of cement paste containing graphene based on surfactant

Recently, the excellent performance of graphene-based materials has attracted civil engineering researchers in its application in cementitious mixtures. However, the application of graphene is hindered by its high cost and the agglomeration phenomenon in cementitious mixtures. In this regard, it is necessary to choose a dispersing agent with the ability to effectively separate graphene layers as well as improve mechanical properties and impermeability of cementitious mixtures. In this study, the effect of surfactant as a graphene separating agent from graphite on the mechanical properties and microstructure of cement paste containing water-dispersed graphene was investigated. The microstructure of the produced graphene reveals that the process of manufacturing graphene by peeling the surfactant leads to fragmentation and rupture of graphite. After 7 days of curing, the compressive strength of cement paste containing a mixture of 5 g / l graphite and 0.56 g / l surfactant increased by 28.66% compared to the control mixture. The crystallography and thermogravimetric results showed that graphene accelerates the formation of CH and C-S-H due to its nucleating effect in the cement matrix. Furthermore, the incorporation of graphene and surfactant into cement paste reduced the voids by 18.6%. This study shows that graphene dispersed in water produced by 0.56 g / l surfactant has the potential to be used as a novel additive in cement-based mixtures.