Recently, graphene oxide (GO) is one of the nanomaterials that enhance the performance of cement-based materials. In this paper, the effects of different mass of GO on the workability and mechanical properties of UHPC is studied, and its mechanism is explored by micro-nano analysis methods such as XRD, SEM, MIP and nano indentation. The results show that, compared with the reference group, the 0.04% GO addition reduces the fluidity of UHPC, reduces the initial and final setting time of slurry, and enhance the compressive strength, flexural strength and tensile strength of the sample at 28d by 15.8%, 14% and 15.3%, respectively. Micro-nano analysis results show that GO promotes cement hydration, reduces the porosity of UHPC, improves the microstructure of the interface transition zone between steel fiber and matrix, and improves the nano-mechanical properties. This is mainly attributed to the nucleation effect of GO and interfacial bonding with C-S-H gel.

最近，氧化石墨烯（GO）是一种可以提高水泥基材料性能的纳米材料。本文研究了不同质量的GO对UHPC的可加工性和力学性能的影响，并通过XRD、SEM、MIP和纳米压痕等微纳米分析方法探索其机理。结果表明，与参比组相比，0.04%的GO添加降低了UHPC的流动性，减少了浆料的初凝和终凝时间，使样品在28d时的抗压强度、抗弯强度和抗拉强度提高了15.8 %、14% 和 15.3%。微纳分析结果表明，GO促进水泥水化，降低UHPC孔隙率，改善钢纤维与基体界面过渡区的微观结构，并提高纳米力学性能。这主要归因于 GO 的成核效应和与 CSH 凝胶的界面结合。