Multiobjective optimization of belite-rich cement-fly ash-limestone concrete considering strength, durability, and sustainability indicators

초록

In conventional low-carbon concrete design, the focus has predominantly been on optimizing the compressive strength and reducing carbon emissions, typically measured as the global warming potential (GWP), while long-term durability and varied environmental impacts have often been overlooked. This narrow scope can lead to incomplete sustainability assessments and increased life cycle risks, such as reinforcement corrosion. To address these limitations, this study presents a holistic multiobjective optimization framework for belite-rich cement-fly ash-limestone (BRCFA-LM) ternary concrete. The study aims to address three key gaps: (1) the lack of systematic, statistics-based analyses of this novel ternary system; (2) the omission of durability indicators such as electrical resistivity in conventional strength-GWP optimization; and (3) the limited environmental scope and neglect of other critical sustainability metrics. Three progressive optimization scenarios were constructed using a simplex centroid design. In scenario 1 (conventional), only strength and the GWP were considered; in scenario 2 (durability-inclusive), surface resistivity was added as a durability target; and in scenario 3 (comprehensive), strength, resistivity, and reduction were optimized simultaneously across six environmental indicators: the global warming potential (GWP), abiotic depletion potential (ADP), ozone depletion potential (ODP), acidification potential (AP), eutrophication potential (EP), and photochemical ozone creation potential (POCP). The results revealed distinct optimal mixtures: FA = 21.92% and LM = 0% in scenario 1; FA = 5.61% and LM = 13.92% in scenario 2, demonstrating the synergistic increase in durability when both LM and FA are incorporated; and FA = 13.33% and LM = 7.33% in scenario 3, highlighting the superior overall sustainability of FA. The experimental validation results revealed discrepancies of less than 5%. In summary, this work advances sustainable concrete design by explicitly integrating durability and multifaceted environmental objectives into a unified optimization framework, quantitatively revealing the critical trade-offs neglected in conventional practice.

키워드