Physical-chemical characteristics of an eco-friendly binder using ternary mixture of industrial wastes

Abstract

This study explores the physical-chemical characteristics of paste and mortar with an eco-friendly binder named as SFC cement, produced by a ternary mixture of industrial waste materials of ground granulated blast furnace slag (S), Class F fly ash (FFA), and circulating fluidized bed combustion fly ash (CFA). To trigger the hydration, the CFA, which acted as an alkaline-sulfate activator, was added to the blended mixture of slag and FFA. The water to binder ratio (W/B), curing regime, and FFA addition significantly affected the engineering performances and shrinkage/expansion of the SFC pastes and mortars. The SFC mortars had higher workability than that of ordinary Portland cement (OPC). With similar workability, the SFC mortars had compressive strengths and expansions comparable to OPC mortars. The main hydration products of the hardened SFC cement were ettringite (AFt) and C-S-H/C-A-S-H. The transformation of the AFt to the monosulfates was observed as the hydration time increased.