Sustainable engineered cementitious composites: Eco‐economic optimization using ultrafine palm oil fuel ash at a low water‐binder ratio

Abstract This study investigates the development of a sustainable Engineered Cementitious Composite (ECC) by utilizing ultra‐fine (1.7 μm) palm oil fuel ash (UFT‐POFA) in a low water‐to‐binder ratio (0.22) mix. To mitigate the economic and environmental impacts of high cement usage, a 400°C thermal treatment for UFT‐POFA was microstructurally and economically validated against treatments from existing literature. This study's methodology involved two phases. Initially, UFT‐POFA was processed and characterized. Subsequently, ECC was evaluated using mixtures with 0%, 15%, 25%, 35%, and 45% UFT‐POFA as a partial substitution for cement. The performance of these composites was then assessed through flowability, compression, and flexural tests. Results demonstrated that the 400°C treatment effectively produced UFT‐POFA meeting ASTM C618‐15 standards with enhanced pozzolanic activity. The inclusion of UFT‐POFA improved flowability. An optimal 15% UFT‐POFA replacement maximized both compressive and flexural strengths. Although higher concentrations reduced strength, they significantly enhanced ductility, as evidenced by increased flexural deflection and the formation of finer microcracks, confirming UFT‐POFA's efficacy in producing more ductile and sustainable ECC.