Dispersion of Thermally Reduced Graphene Oxide in Simulated Hydrated Cement Environment and Study on Performance and Mechanism of Graphene Reinforced Mortar

Graphene nanosheets can greatly improve the properties of cement-based materials, but how to improve the dispersion of graphene nano-sheets in calcium and alkaline-abundant cement hydration environment is a key problem. In this study, a polyaromatic water reducer (JS) was used as a dispersant to study the dispersion of reduced graphene oxide (rGO) prepared by high temperature thermal reduction in saturated calcium hydroxide (CH) solution used to simulate hydrated cement system rich in calcium and alkaline environment. The study showed that when the mass ratio of JS to cement was 1.5%, rGO could be well-dispersed in CH solution. The mechanical test of graphene-mixed cement mortar showed that when the mass content of rGO to cement was 0.05%, the 3 d flexural and compressive strength were increased by 9.5% and 11.1%, respectively and the 28 d flexural and compressive strength were increased by 6.74% and 26.5% respectively. The chemical bonded water and microscopic tests showed that JS could effectively disperse rGO in hardened cement motar, accelerate the hydration process of cement paste and regulate the crystal growth of hydrated products. © 2020, Materials Review Magazine. All right reserved.