Dispersion technical index of GO.

To exploretheeffects of physical, mechanical, anti-deterioration properties of graphene oxide (GO) on cement-based cementitious materials, GO sheet dispersions areprepared by the improved Hummers method and ultrasonic dispersion method. The influence of theGO content on the compressive and flexural strengths of cement paste is investigated, and the penetration process of chloride ions in graphene oxide concrete is discussed by the electric accelerated erosion method. Combined with the rapid freeze-thaw test, the deterioration of graphene oxide concrete ismethodically analyzed. Theobtained results reveal that an appropriate amount of GO improves both the compressive and flexural strengths of cement pastev. In the chloride environment, the chloride diffusion coefficient of 0.03% GO concrete is 18.75% less than that of ordinary concrete.Under the action of freeze-thaw cycles, with the increase of salt freezing times, the deterioration mode of GO concrete is a combination of mortar shedding, micro-crack expansion, denudation, and block shedding; The stress-strain curve of the specimen tends to be flat with the growth of salt freezing times. The peak stress gradually lessens, the peak strain gradually grows, and the elastic modulus remarkably reduces. Compared with ordinary cement paste, theGO is capable of promoting the growth of cement paste hydration crystals, changing the size and shape of crystals, and realizingthe regulation of cement paste microstructure. Incorporating an appropriate amount of theGO could promote the cement hydration process and enhance the chemical water-binding amount in the cement paste. The optimal GO content is reported to be 0.03% of the cement mass.为探究氧化石墨烯（graphene oxide, GO）对水泥基胶凝材料的物理、力学及抗劣化性能的影响，本研究采用改进的Hummers法与超声分散法制备氧化石墨烯片层分散液。研究了GO掺量对水泥浆体抗压与抗折强度的影响，并通过电加速侵蚀法探讨了氯离子在氧化石墨烯混凝土中的渗透过程。结合快速冻融试验，对氧化石墨烯混凝土的劣化过程进行了系统分析。研究结果表明，适量掺加GO可同时提升水泥浆体的抗压与抗折强度。在氯离子环境中，掺量为0.03%的GO混凝土的氯离子扩散系数较普通混凝土降低18.75%。在冻融循环作用下，随着盐冻次数的增加，GO混凝土的劣化模式呈现为砂浆剥落、微裂纹扩展、剥蚀与块状脱落的复合形式；随着盐冻次数增长，试件的应力-应变曲线趋于平缓，峰值应力逐渐降低，峰值应变逐步增大，弹性模量显著下降。与普通水泥浆体相比，GO可促进水泥浆体水化晶体的生长，改变晶体的尺寸与形貌，实现对水泥浆体微观结构的调控。掺加适量GO可促进水泥水化进程，提升水泥浆体的化学结合水量。研究表明，GO的最优掺量为水泥质量的0.03%。