Synergistic strengthening mechanism of Portland cement paste reinforced by a triple hybrid of graphene oxide, functionalized carbon nanotube, and nano-silica

This study investigates the synergistic strengthening mechanism of graphene oxide (GO), functionalized carbon nanotubes (f-CNT), and nano-silica (NS) triple hybrid-reinforced Portland cement composite. GO was selected as the variable owing to the synergistic effect of GO with both f-CNTs and NS upon dispersion by forming bonds with both nanomaterials. At a low GO dosage (similar to 0.03 wt% of cement), the bond between GO and NS deteriorated the dispersion in Ca2+-rich solution due to the overly attached NS on the GO surface. The highest GO fraction (0.05 wt%) also led to poor dispersion as the excess GO was agglomerated by Ca2+ ions. However, an optimal amount of GO (0.04 wt%) significantly improved the dispersion quality. The enhanced dispersion of the triple hybrid positively influenced the hydration degree and mechanical performance of the cement paste (133 % and 156 % for compressive and tensile splitting strength compared to OPC) and the pozzolanic reactivity of NS.

Automated summary

This study investigates the synergistic strengthening mechanism of graphene oxide, functionalized carbon nanotubes, and nano-silica triple hybrid-reinforced Portland cement composite. The study found that an optimal amount of graphene oxide significantly improves the dispersion quality and positively influences the hydration degree and mechanical performance of the cement paste.