石墨烯对水泥净浆力学性能及微观结构的影响

Effect of graphene on mechanical properties and microstructure of cement paste

为改善石墨烯纳米材料疏水性,采用硝酸氧化和超声波法制备石墨烯分散悬浮液,考察石墨烯质量分数对水泥净浆力学性能及其微观结构的影响,探讨石墨烯的增强增韧作用机制,结果表明,水泥基复合材料的抗压、抗折强度随着石墨烯质量分数的增加呈先增大后减小的趋势,且最佳质量分数为水泥质量的0.02%.通过SEM和FT-IR对硬化水泥石的结构进行表征,发现石墨烯能够促进水泥水化产物的生长,改变水化晶体的形状、尺寸,使其有形成完整、簇状的趋势,但并未与水泥发生化学反应,改变其生成物类型.

Graphene suspension was prepared by nitric acid oxidation and ultrasonic to improve the hydrophobicity. Graphene suspension was added to cement to produce cement-graphene composite. The effect of graphene on mechanical properties and microstructure of cement paste was studied. In addition, the toughing mechanism of grapheme was also discussed, which provide theoretical and practical foundation for the study of graphene cement-based composite materials. With the increase of graphene content, the compressive and flexural strength of cement-based composite increased firstly then decreased, and the optimal additive amount is 0. 02 wt%. The results from structural analysis of set cement by SEM and FT-IR indicated that graphene can promote the growth of the hydration products, change the shape and size of hydration crystal, but did not change its type through reacting with cement and graphene.