Resistance of graphene oxide-modified cement pastes to hydrochloric acid attack

Abstract

This study investigated the hydration, rheology, and diffusion resistance of cement pastes involving up to 0.09 wt% graphene oxide (GO) under constant exposure to hydrochloric (HCl) acid for four weeks. Samples containing 0.09 wt% GO revealed a reduction in mass loss and sectional area loss when compared to the control sample without any GO, highlighting the potential of GO inclusion in improving the resistance of the cement matrix to acid attack. While higher GO dosages reduced the workability and hydration of the fresh paste, the use of GO improved the diffusion resistance of the cement matrix against HCl exposure by densifying the microstructure. The presence of alumina-silica hydrogel was observed in the altered zones of the acid exposed specimens. While this chemical change occurred in all GO-modified pastes, the micro-hardness of the sample containing 0.09 wt% GO was higher than the control sample (i.e. without any GO). The obtained results indicated that the inclusion of up to 0.045 wt% GO increased the micro-hardness and reduced the leaching of aluminium and silicon ions, which could effectively prevent the increased formation of microcracks and form a protective barrier against aggressive species in extreme environments.