Economy, Energy, and Environment Impact on the Use of Ferronickel Slag Waste for Construction Project in Indonesia

Abstract

This research intends to investigate the economic, energy and environmental aspects of mortar and concrete manufactured with ferronickel slag (FNS) as a substitute for cement and aggregate because many infrastructure projects in Indonesia use waste materials, particularly FNS, as one of the construction components. Results indicate that incorporating FNS powder as one material in construction projects also has indirect benefits such as generating employment, and fostering local community economic growth. The grinding of FNS will provide business opportunities for Micro, Small and Medium-sized Enterprises (MSMEs). The use of FNS as sand replacement affords an economy advantage in concrete production which also benefits in the construction sector. In addition, utilizing by-products (FNS 1 and FNS 2) in mortar production has a beneficial effect on lowering the LCC. However, adding FNS in place of sand does not reduce the LCC of concrete constructed with FNS. The usage of FNS in place of cement appears to help reduce mortar's energy consumption. However, using FNS in place of sand throughout the concrete-making process has minimal impact on energy usage. There is an environmental benefit to using FNS 1 and FNS 2 in the mortar production process. When concrete is built using FNS as a sand substitute, the CO<sub>2</sub> emission does not show the same favourable outcomes as mortar made with FNS powder. Although it doesn't significantly reduce carbon emissions, FNS sand significantly improves concrete's performance.