Feasibility of ferronickel slag powder for cementitious binder in concrete mix

This study aims at utilizing ferronickel slag (FNS) powder for replacing for ordinary Portland cement (OPC) in concrete. Three types of FNS in different fineness and replacement were used to find which is the most beneficial to be used as binder. FNS concrete was assessed at compressive, flexural, shear and splitting tensile strength tests along with measurement of setting time, hydration heat and drying shrinkage for physical performance. Durability was evaluated by the resistance to chemical degradation against chloride ion penetration, carbonation and sulfate attack. Hydration characteristics of the ferronickel slag paste were identified by scanning electron microscopy observation and pore size analysis. It was found that FNS concrete might have a lower strength at an early age, which was substantially overcame with time then to meet the strength for OPC concrete in a long term, presumably due to a latent hydration. When it comes to durability, chloride transport and sulfate attack were mitigated in FNS concrete, whilst carbonation could be more often prevailed. However, a reuse of industrial waste could enhance the economic benefit and simultaneously lower the CO2 emission in concrete production. (C) 2019 Elsevier Ltd. All rights reserved.