Finite Element Modeling of Reinforced Concrete beam Strengthened by Concrete Overlay

This study investigates the flexural behavior of reinforced concrete beams strengthened with a con-crete overlay under static loading conditions. Numerical simulations were performed using ABAQUS, and the finite element model was validated against experimental data to ensure accuracy. A comprehensive parametric study was conducted, considering variables such as overlay thickness, the area of longitudinal tensile reinforcement, and the compressive strength of concrete. Key perfor-mance indicators—including load-deflection behavior, flexural capacity, and ductility ratio—were analyzed. The findings reveal that increasing the thickness of the concrete overlay leads to a reduc-tion in both flexural stiffness and ultimate moment capacity across all types of interface conditions, compared to the un-strengthened control beam. In contrast, enhancing the compressive strength of the overlay resulted in a 7% increase in load-bearing capacity. Although stiffness improved, a no-ticeable decrease in ductility was observed, with the ductility ratio reaching 5.8. Furthermore, both higher overlay compressive strength and a greater area of longitudinal reinforcement were associated with improved flexural performance.