氧化石墨烯对水泥基复合材料微观结构的调控作用及对抗压抗折强度的影响

通过氧化法制备得到氧化石墨烯（GO），通过GO与丙烯酸（AA）和丙烯酰胺（AM）进行插层聚合反应制备得到插层复合物GO/P（AA-AM）。检测结果表明，GO在插层复合物中具有较小的尺寸和均匀的分布，将GO/P（AA-AM）掺入水泥基复合材料中，发现水泥水化产物成为规整的针状、棒状或多面体状晶体，并且能够聚集形成具规整形貌的微观结构和宏观结构，水泥基复合材料中的裂缝及有害孔洞比对照样品明显减少，其抗压强度和抗折强度比对照样品有明显提高。提出了GO纳米片层对于水泥基复合材料规整结构的调控机理，认为GO纳米片层及活性基团能够促进水泥化产物形成规整形状的水化晶体，最初形成的水化晶体成为后续水化晶体形成的模板，通过晶体的生长最终形成规整水化晶体及规整的微观结构和宏观结构。

Regulation of graphene oxide on microstructure of cement composites and its impact on compressive and flexural strength

Graphene oxide (GO) was prepared by oxidation, and the intercalation composite of GO/P(AA-AM) was prepared by intercalation polymerization of GO with acrylic acid(AA) and acrylamide (AM). The testing results indicated that GO nanosheets in the GO/P(AA-AM) had smaller size and uniform dispersion. Meanwhile, it is found that GO nanosheets can regulate the cement hydration products to form regular needle-like, rod-like, or polyhedron-like crystal, also ordered microstructure and macrostructure. The cracks and harmful pores in the cement composites have obviously decreased. The compressive and flexural strength have significant increase compared with the control samples. The regulation mechanism of GO nanosheets on cement hydration crystals and the microstructure of cement composites were proposed. It thinks that GO nanosheets with active chemical groups have the promoting and template effects on forming regular shapes of cement hydration crystals. The initial regular crystals play a template role for later formed crystals, and finally form large-volume and regular shape crystals and ordered microstructure and macrostructure by crystals growing.