The overall strength, serviceability, and durability characteristics of structural systems are a combination of the interaction of their constitutive materials. Therefore, this study examines the flexural behavior of reinforced concrete (RC) beams jacketed using a new strengthening system with a hybrid combination between the steel fibers and the polyvinyl-alcohol-engineered cementitious composites (PV-ECC). Simply supported beams with 325 mm depth, 200 mm width, and 3500 mm length were numerically simulated with SPH-ECC jackets using ABAQUS software after being well-validated using experimental results from the literature. The extent effect of the material properties was addressed using three conventional concrete strength values (20, 40, and 60) MPa and three SPH-ECC compressive strength values (60, 80, and 100) MPa. Results were addressed and introduced in terms of the relative strength ratios between the original system and the strengthening layers with proper justifications on the observed phenomenon of the interaction between low and high-strength concretes.