This study explores the use of areca nut husk fiber and marble dust as a substitute for a portion of cement in concrete. The research aims to evaluate the mechanical properties, structural behaviour, and durability of concrete modified with these materials. Both analytical modelling and experimental testing were conducted to evaluate the concrete's performance. During the experimental phase, concrete specimens containing different proportions of marble dust and areca nut husk fiber were prepared. Experiments were carried out to assess compressive strength and tensile strength. Additionally, a finite element analysis was performed to simulate the performance characteristics of the altered concrete. The findings suggest that incorporating 2% ANHF yields the greatest improvement in mechanical properties, establishing it as the optimal dosage for further evaluation. At 28 days, compressive strength exhibited a 17.6% increase compared to conventional concrete, while tensile strength improved by 26.8%. However, increasing the ANHF content to 3% resulted in a reduction in strength properties. The combination of these materials also contributes to a reduction in environmental impact by utilizing agricultural waste and industrial byproducts.