Optimizing granite waste aggregate content in self-compacting concrete using multi criteria decision approach

Abstract

This study aims to assess the technical, environmental, and multi-criteria performance of fly ash (FA) modified self-compacting concrete (SCC) incorporating granite waste aggregate (GWA). Nine SCC mixtures were developed by replacing cement with a constant 30 % FA and natural fine aggregate (NFA) with varying GWA contents ranging from 0 % to 60 %. Technical properties such as compressive strength, water permeability, water absorption, sorptivity, and chloride ion diffusion were evaluated. Results showed an increase in compressive strength of around 20 % with up to 40 % GWA incorporation. Mixtures containing up to 50 % GWA exhibited reductions in water permeability, water absorption, sorptivity (i.e., capillary rise), and chloride ion penetration by around 53 %, 15 %, 24 %, and 25 %, respectively, compared to the FA modified control SCC mix. SEM analysis confirmed a denser microstructure in SCC containing up to 50 % GWA. The environmental performance of SCC incorporating FA and GWA was evaluated through life cycle assessment (LCA), which indicated significant reductions in environmental impacts, like, 26 % in global warming potential, 23 % in mineral resource scarcity, 25 % in fossil resource scarcity, and 11 % in ozone formation. Additionally, multi-criteria decision-making (MCDM) analysis using both TOPSIS and VIKOR methods identified 30–35 % GWA as the optimal dosage for SCC mixes. Overall, SCC mixtures incorporating 30 % GWA demonstrated the most balanced performance, making them ideal for use in densely reinforced structural elements due to their enhanced technical and environmental benefits. © 2025 Elsevier B.V.