Surface abrasion resistance of high-volume fly ash concrete modified by graphene oxide: Macro- and micro-perspectives

Recent studies have demonstrated that graphene oxide (GO) can be used as a promising nano-sized additive to improve the mechanical properties and durability performances of cement composites. In this laboratory study, the effect of admixed GO on the properties of high-volume fly ash (HVFA) concrete, especially its surface abrasion resistance, was investigated. Compressive strength, microhardness, and tribological properties of HVFA mixtures were also measured to investigate their possible correlations with the abrasion resistance. The addition of GO (up to 0.1% by weight of cementitious materials) increased the compressive strength at the macro level and friction coefficient at the micro level, both of which could be related to the surface abrasion resistance of HVFA concrete. Microhardness and scratch test results showed that the HVFA mixtures achieved the best performance with GO admixed at 0.05 wt%, which was confirmed by the microstructure investigations by XRD and SEM/EDS. In addition, the agglomeration of GO may occur at a dosage higher than 0.05 wt%.