▎ 摘 要
Graphene oxide (GO), which has been sucessfully used in cement composites as an admixture, can improve their mechanical and durability properties. This study examined and elucidated the effect of GO on the hydration products of a cement system in detail. The hydration precursors, morphology, composition, and chemical bonds of cement pastes were studied by SEM/BSE, XRD, LA-ICP-MS, and Si-29/Al-27 MAS-NMR, respectively. The experimental results indicated that the 28-day compressive strength of cement pastes (w/c = 0.35) was increased by 29% when admixing 0.02 wt% GO. There existed chemical reactions between the admixed GO and the cement hydration products. The improved strength actually was not only attributed to the improved hydration degree of cement, but also the newly found tobermorite-like hydrates and jennite-like hydrates due to the Ca ions consumption by the negatively charged GO. The polymerization of hydration products was also improved due to the addition of GO. Published by Elsevier Ltd.