Synergistic Effects of Fly Ash and Graphene Oxide on Workability, Mechanical Property of Cement-Based Materials

Graphene oxide (GO) has good effect on the microstructure and mechanical property of cement-based materials, but its noticeable side-effect on workability would greatly limit its future engineering application. In the present paper, the synergistic effects of GO and fly ash (FA) on fluidity and compressive property were studied systematically. To begin with, based on orthogonal test scheme, series of mix proportion were proposed, considering the GO dosage, FA replacement ratio and water/binder (w/b) ratio. And then, comprehensively considering fluidity and compressive property, the synergistic effects of GO and FA were investigated and a more practical and optimal mix proportion was proposed. Afterwards, based on the as-proposed mix proportion, the results of the fluidity, compressive property illustrated that a more balanced enhancement effect were obtained, which was further confirmed by SEM tests. Moreover, the mechanism of synergistic effects were proposed, including uniform dispersion, reasonable hydration process, higher degree of pozzolanic reaction and optimal size gradation.