▎ 摘　　要

In this study, the effects of graphene oxide/isobutyltriethoxysilane (GS) composite emulsion, ordinary fly ash (OFA), and silanemodified fly ash (SFA) on the mechanical and waterproofing performances of hardened cement pastes (HCPs) were investigated. In addition, the influence of OFA and SFA on the protective effect of GS was studied. The results showed that GS decreased the compressive strength of the HCPs and significantly improved their waterproofing performance. The compressive strength and waterproofing performance of the HCPs decreased because of the replacement of cement with fly ash (FA), but its toughness improved owing to the effect of FA refining the crystal size of calcium hydroxide. Compared with OFA, SFA was conducive to forming a denser gel network structure composed of SFA, GS, and calcium-silicate-hydrate (C-S-H), significantly improving the performance of the HCPs and the protective effect of GS.