Multiobjective optimization of the performance, cost, and environmental impact of multimineral admixtures mortar

초록

To simultaneously reduce CO2 emissions and material costs without hindering structural performance, we use a multimineral binder design instead of single-SCM substitutions. We therefore develop a response-surface-driven multiobjective optimization framework to identify robust proportions of limestone powder (LS), calcined clay (CC), and fly ash (FA) to meet combined performance-cost-environmental impact criteria. This study presents the comprehensive optimization of multicomponent cementitious mixtures that use LS, CC, and FA as partial replacements for ordinary Portland cement (OPC). A Box-Behnken design (BBD) and response surface methodology (RSM) were employed to systematically assess 19 mix designs with various substitution levels. Experiments were performed to evaluate compressive strength and electrical resistivity, whereas cost and environmental impacts, including six key indicators: global warming potential (GWP), abiotic depletion potential (AD), ozone depletion potential (ODP), acidification potential (AP), eutrophication potential (EP), and photochemical ozone creation potential (POCP), were quantified on a per-volume and strength-normalized basis. The results indicated that FA reduced the environmental burden and cost but considerably decreased the strength, whereas appropriate dosages of LS and CC improved performance and durability. The electrical resistivity increased up to 1773%, indicating substantial pore refinement. Strength-normalized impact analysis revealed that optimized SCM combinations could reduce the GWP and POCP by 27.8% and 28.7%, respectively. Multiobjective optimization revealed the optimal blend (7.08% LS, 13.51% CC, and 9.77% FA), which balanced mechanical, economic, and environmental performance. Experiments confirmed that the prediction errors fell within 5%, validating the reliability and engineering feasibility of the model. This work provides not only an effective optimization framework for sustainable concrete mix design but also practical guidance for low-carbon construction materials for real-world applications.

키워드