Graphene oxide/cement composite was prepared using a graphene oxide aqueous solution. The workability and mechanical properties of graphene oxide/cement composite with different concentrations for graphene oxide and the ratio of water to cement were investigated. The results observed were the fluidity of cement pastes decreased noticeably with the addition of graphene oxide and increased with the increase in the ratio of water to cement for all tested samples of different graphene oxide contents. It is indicated that a noticeable inverse correlation between the concentration of graphene oxide and fluidity was observed, and a positive linear relationship between the ratio of water to cement and fluidity was also obtained. The compressive strength of cement pastes significantly improved in the presence of an appropriate concentration of graphene oxide as compared to that of the cement paste without graphene oxide; this difference was due to the denser microstructure of graphene oxide/cement composite than that of the control specimens. With the combined analysis of X-ray diffraction and scanning electron microscopy with energy-dispersive spectrometry, the results showed that graphene oxide could promote and regulate the formation and connection of calcium hydroxide and calcium silicate hydrate during the hydration reaction, forming numerous regular and extremely compact plate-shaped crystals, and the compact plate-shaped microstructures constituted of not only calcium hydroxide and calcium silicate hydrate but also wrapped ettringite. This investigation will provide a flexible way to preparation of graphene oxide/cement composite with wanted fluidity and optimized compressive strength that promote the industry application of graphene oxide/cement composite.

中文翻译：

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氧化石墨烯增强水泥复合材料和易性及力学性能改性机理研究

使用氧化石墨烯水溶液制备氧化石墨烯/水泥复合材料。研究了不同氧化石墨烯浓度和水水泥比的氧化石墨烯/水泥复合材料的可加工性和力学性能。观察到的结果是，对于不同氧化石墨烯含量的所有测试样品，水泥浆体的流动性随着氧化石墨烯的加入而显着降低，并随着水与水泥比的增加而增加。结果表明，观察到氧化石墨烯的浓度与流动性之间存在显着的负相关，并且还获得了水水泥比与流动性之间的正线性关系。与不含氧化石墨烯的水泥浆相比，在适当浓度的氧化石墨烯存在下，水泥浆的抗压强度显着提高；这种差异是由于氧化石墨烯/水泥复合材料的微观结构比对照样品的微观结构更致密。通过X射线衍射、扫描电镜和能谱仪的联合分析，结果表明氧化石墨烯在水化反应过程中可以促进和调节氢氧化钙和硅酸钙水合物的形成和连接，形成大量规则的、极致密的板状晶体，致密的板状微结构不仅由氢氧化钙和水合硅酸钙构成，还由包裹钙矾石构成。