The use of graphene derivatives to improve the performance of cement mortar composites has received significant attention in recent years. However, because of diversity of graphene derivatives and their properties, which depend on their preparation, it is critical to consider their size, surface chemistry, crystallinity, surface area, and impurity. In particular, there is still lack of understanding on the influence of the graphene particle size on the performance of cement mortar composite. This paper presents the study on the size effect of reduced graphene oxide (rGO) on physiochemical and mechanical properties of cement mortar composites. A series of rGOs with different particle sizes were prepared by different sonication times of 1, 2, 4, 6, and 8 h and then added with optimum dosage of 0.1% to the composites. The mechanical test results revealed that the composite containing rGO with 0.1% dosage and particle size of 169.8 ± 5.8 nm prepared with 4 h sonication time has 53% and 91% higher tensile and compressive strengths at 28 days than the plain cement mortar composite, respectively, which are higher than those obtained by the use of rGO with particle size of 245.0 ± 29.3 nm prepared with 1 h sonication time. This is explained by the higher molecular bonding, hydration degree, and crystallinity of the composite incorporating rGO with a smaller particle size. This study provides a valuable contribution toward better understanding of the influence of rGO particle size on the properties of cementitious composites to optimize their performance.

近年来，使用石墨烯衍生物来改善水泥砂浆复合材料的性能受到了极大的关注。然而，由于石墨烯衍生物及其性质的多样性取决于其制备，因此至关重要的是考虑其尺寸，表面化学性质，结晶度，表面积和杂质。特别是，对于石墨烯粒度对水泥砂浆复合材料性能的影响仍然缺乏了解。本文介绍了还原氧化石墨烯（rGO）对水泥砂浆复合材料的理化和力学性能的尺寸效应的研究。通过1、2、4、6和8小时的不同超声处理时间，制备了一系列具有不同粒径的rGO，然后以0.1％的最佳剂量添加到复合材料中。力学测试结果表明，在4 h超声处理下制备的含rGO的复合物（含0.1％剂量的rGO）和169.8±5.8 nm粒径的复合材料在28天时的拉伸强度和抗压强度分别比普通水泥砂浆复合材料高53％和91％。高于使用1 h超声处理时间制备的，粒径为245.0±29.3 nm的rGO获得的结果。这可以通过掺入较小粒径的rGO的复合材料的更高的分子键合，水合度和结晶度来解释。这项研究为更好地了解rGO粒度对水泥基复合材料性能的影响提供了宝贵的贡献，以优化其性能。超声处理4 h制备的8 nm在28天时的抗拉强度和抗压强度分别比普通水泥砂浆复合材料高53％和91％，这比使用rGO的245.0±29.3 nm粒径要高。用1小时的超声处理时间制备。这可以通过掺入较小粒径的rGO的复合材料的更高的分子键合，水合度和结晶度来解释。这项研究为更好地了解rGO粒度对水泥基复合材料性能的影响提供了宝贵的贡献，以优化其性能。超声处理4 h制备的8 nm在28天时的抗拉强度和抗压强度分别比普通水泥砂浆复合材料高53％和91％，这比使用rGO的245.0±29.3 nm粒径要高。用1小时的超声处理时间制备。这可以通过掺入较小粒径的rGO的复合材料的更高的分子键合，水合度和结晶度来解释。这项研究为更好地了解rGO粒径对水泥基复合材料性能的影响提供了宝贵的贡献，以优化其性能。在1 h超声处理时间内制备3 nm。这可以通过掺入较小粒径的rGO的复合材料的更高的分子键合，水合度和结晶度来解释。这项研究为更好地了解rGO粒度对水泥基复合材料性能的影响提供了宝贵的贡献，以优化其性能。在1 h超声处理时间内制备3 nm。这可以通过掺入较小粒径的rGO的复合材料的更高的分子键合，水合度和结晶度来解释。这项研究为更好地了解rGO粒度对水泥基复合材料性能的影响提供了宝贵的贡献，以优化其性能。