▎ 摘　　要

The excellent performance of graphene-based materials to use in concrete has recently attracted the attention of civil engineering researchers. However, the application of graphene faces obstacles due to the high cost of graphene and agglomeration phenomena in cementitious composites. As a result, research into the production of water-dispersed graphene, a combination of graphite and a dispersing agent, is a particularly cost-effective alternative. In this regard, it is essential to select a dispersing agent capable of effectively separating graphene layers while also improving mechanical properties and impermeability. In this study, the influence of two different dispersive agents, surfactant (S) and superplasticizer (SP), on mechanical properties, permeability, and microstructure of cement paste was investigated. SEM, TEM, and Raman spectroscopic analyses demonstrate that multilayer graphene sheets made using superplasticizer have higher quality and fewer defects than surfactantbased sheets. After 3 days of aging, the compressive strength of graphene-containing cement paste with 0.1 % superplasticizer increased by 82.05 % compared to the control paste. On the other hand, a decrease in sorptivity by 54 % compared to the control paste is observed by graphene-containing cement paste with 0.56 g/l surfactant. The microstructure investigation revealed that graphene accelerates the CH and C-S-H productions due to the nucleation effect in the composite cement matrix; however, the effect of SP is more significant than S in cementitious composites. This research suggests that water-dispersed graphene generated by 0.1 % SP and 0.56 S g/l has the potential to be used as an innovative admixture in cement-based composite materials.