▎ 摘　　要

Graphene and graphene oxide (GO) sheets have great potential to improve the properties of traditional cement-based building materials. This research studied the effects of graphene and GO sheets on the flexural and compressive strength of cement paste. After dispersion into water with an effective surfactant, graphene and GO sheets can be stored stably for several days. As the proportion of graphene and GO sheets increased from 0% to 0.1% by weight, the mechanical properties of the nanocomposites were improved significantly. With the addition of 0.05% by weight graphene sheets, the flexural strength of the samples increased by 38% and 23% at 7 and 28 days, respectively. The compressive strength of specimens was also improved by the addition of graphene sheets. However, the results showed that high content of GO sheets has an adverse impact on the mechanical properties. Scanning electron microscopy (SEM) and mercury intrusion porosimetry (MIP) analysis showed that the addition of graphene sheets improved pore-diameter distribution and formed a compact microstructure of cement paste. (c) 2019 American Society of Civil Engineers.