Revisiting the strengthening mechanisms of graphene oxide reinforced cement: Effects of dispersion states

When GO suspension is mixed with cement, different GO dispersion states exist, including well-dispersed state (WDS), grain-adsorbed state (GAS), and self-agglomerated state (SAS). Although the seeding effect mechanism of GO in WDS is well accepted, how GO in GAS and SAS impacts hydration is still an open question. In this study, we selectively studied the effects of GAS and SAS on tricalcium silicate (C 3 S) hydration. The results revealed that GO in GAS limits the accessibility of reactant for hydration at early age, without notably affecting the subsequent hydration. Instead, GO in SAS strongly absorbs calcium ions from pore solution to significantly decrease its over-saturation degree, which results in more tightly compacted hydrates formed on C 3 S surface and thus inhibits hydration. These results lead to an improved understanding of GO in cement hydration , and help us unlock the potential of GO in cementitious materials .