▎ 摘　　要

This research aimsto investigate the synergistic reinforcing mechanismsof chemically combined graphene oxide and nanosilica (GO-NS) in thestructure of calcium silicate hydrate (C-S-H) gels compared with physicallycombined GO/NS. The results confirmed that the NS chemically depositedon the GO surface formed a coating to keep GO from aggregation, whilethe connection between GO and NS in GO/NS was too weak to preventGO from clumping, making GO-NS better dispersed than GO/NS in poresolution. When applied to cement composites, the incorporation ofGO-NS enhanced the compressive strength by 27.3% after 1-day hydrationcompared to that of the plain sample. This is because that GO-NS generatedmultiple nucleation sites at early hydration, reduced the orientationindex of calcium hydroxide (CH), and increased the polymerizationdegree of C-S-H gels. GO-NS acted as the platforms for the growingprocess of C-S-H, enhancing its interface bonding strength with C-S-Hand increasing the connection degree of the silica chain. Furthermore,the well-dispersed GO-NS was prone to insert in C-S-H and induceddeeper cross-linking, thereby refining the microstructure of C-S-H.All these effects on hydration products resulted in the mechanicalimprovement of cement.