Synergistic effects and optimization of palm oil fuel ash and jute fiber in sustainable concrete

The extensive use of Portland cement significantly contributes to global carbon emissions, demanding sustainable alternatives in construction. This study investigates the combined influence of palm oil fuel ash (POFA), a supplementary cementitious material, and jute fiber (JF), a natural reinforcement, on the performance and eco-efficiency of concrete. Experimental tests assessed compressive, tensile, flexural strengths, modulus of elasticity, and ultrasonic pulse velocity, alongside embodied carbon and eco-strength efficiency. Response Surface Methodology (RSM) was employed to model responses, while multi-objective optimization determined the ideal mix proportions. Results reveal that incorporating 0.10% JF with 10% POFA enhances mechanical performance by up to 26%, while 25% POFA substitution yields the lowest embodied carbon. The optimized blend (12.66% POFA and 0.244% JF) achieved an 86% desirability index, balancing strength and sustainability. These findings provide new evidence that the integration of agro-waste ash with natural fibers, supported by statistical optimization, offers a viable pathway for producing eco-efficient, high-performance concrete, thereby advancing sustainable construction practices. Future work may extend these findings through microstructural and durability assessment to further validate the long-term sustainability of POFA-JF concrete. © The Author(s) 2026.