Effect of graphene oxide (GO) on the hydration and dissolution of alite in a synthetic cement system

Abstract

An investigation is about the role of GO on the dissolution behaviours and hydration process of alite (Fe, F-C3S, abb. C3S) in a synthetic cement system, which also contains aluminate (Fe, F-C3A, abb. C3A) and gypsum. The results show that GO can increase the undersaturation levels of starting materials (C3S, C3A and gypsum) and thus promote their dissolution. The dissolution of C3A might be more sensitive than that of C3S due to the fluctuation of Ca concentration in pore solution before 30 min. Trace amount of GO could accelerate the interfacial dissolution rate of C3S throughout 24 h. As for the precipitation behaviours, GO could increase the supersaturation level of portlandite while decrease that of ettringite and C–S–H. In general, GO can improve the hydration degree of C3S by up to 15.0% and accelerate its hydration reaction rate by 33.6%. It is notable that the morphology changes of C–S–H from foil-like for reference to fibrous-like for GO-containing system at 2 h were likely attributed to the supersaturation of portlandite.