A targeted approach of using graphene oxide in cement composites

Graphene oxide (GO) has emerged as a promising candidate for improving the strength and toughness of cement composites. However, achieving uniform dispersion of GO in cement composites still presents significant challenges. This study introduces a novel approach whereby sand particles are pre-saturated or pre-coated with GO dispersion before their incorporation with cement, thereby avoiding aggregation of GO when directly introducing it into the cement matrix. The experimental findings indicate that the flow diameter of the optimized cement mortar formulation only marginally reduced by about 2 % as compared to plain mortar. In addition, the 28-day flexural strength of the optimized cement mortar significantly increased by about 40 %. A significant reduction in water sorptivity is also observed in the cement composites containing GO pre-saturated sand or GO-coated sand. The improvements in mechanical strength and water resistance of cement composites can be mainly attributed to the application of GO pre-saturated sand or GO-coated sand, which can effectively improve the dispersion of GO and can targetly enhance the interface transition zone. Especially, the approach of directly pre-saturating sand with GO is more practical for real-world applications due to its straightforwardness, cost-effectiveness, and efficacy. This research thus affirms the efficacy of GO dispersion as a pretreatment for aggregates within cement composites. • A novel approach whereby sand is pre-treated with GO dispersion is proposed and compared. • The application of GO pre-saturated or GO-coated sand can effectively improve the dispersion of GO. • The application of GO pre-saturated or GO-coated sand can targetly enhance the ITZ in cement composites. • GO pre-saturation is practical for real applications due to its simplicity, cost-effectiveness, and efficiency.