Effect of graphene oxide on early hydration and compressive strength of Portland cement-copper tailing powder composite binder

Abstract

The effect of graphene oxide (GO) on early hydration, compressive strength, hydration products and microstructure of Portland cement-copper tailing powder composite binder (CTB) were investigated by applying the isothermal calorimeter, compressive strength, X-ray diffraction analysis, thermos gravimetric and differential thermos analysis, and scanning electron microscopy. The results showed that GO accelerated early hydration and shortened the reaction process of CTB. Moreover, GO was beneficial to the development of compressive strength of CTB specimens prepared with a lower w/b ratio. The addition of GO had limited influence on the quantity of the hydrates of all samples at 3 days. However, at 90 days, incorporating small dosage of GO in CTB could promote the hydration of copper tailing powder, and consumed Ca(OH)2. The effect depended on the GO content, where excess GO could have a negative effect on hydration properties by changing the hydrates' morphology and making the spatial distribution uneven.