This study presents an in-depth experimental and analytical examination of the flexural behavior of full-scale functionally graded high-performance concrete (FGHPC) beams reinforced with a hybrid combination of basalt and glass fibers. The control mix utilized was M70 grade high-performance concrete (HPC), while the functional gradation was attained through the incorporation of hybrid fibers (basalt and glass) of two distinct lengths (6 mm and 12 mm) in various proportions distributed throughout the tensile zone of the beam. The beams were cast in layered configurations to evaluate the influence of fiber gradation on flexural strength, stiffness, ductility, and crack propagation control. Four-point bending tests were performed on simply supported beams measuring 230 × 300 × 2000 mm to determine the ultimate load capacity, mid-span deflection, and stress–strain response. Additionally, a finite element (FE) model was developed in ABAQUS employing the Simplified Concrete Damage Plasticity (SCDP) approach to replicate the flexural performance of M70 grade concrete beams. The model incorporated concrete, steel reinforcement, and hybrid fibers using embedded constraints, and was validated against experimental results, showing strong correlation. The optimum graded hybrid configuration (0.3% basalt + 0.2% glass fibers) exhibited an 18% increase in ultimate load capacity and approximately 50% higher mid-span deflection compared to the control HPC beam, demonstrating significant enhancement in flexural strength and ductility. The findings revealed that functionally graded basalt–glass hybrid fiber reinforced concrete (FG-HFRC) beams exhibited higher load-carrying capacity, stiffness, mid-span deflection, and post-cracking ductility than the control HPC beam. Basalt fibers enhanced crack resistance, while glass fibers improved energy absorption and deformation capacity. Thus, functional gradation of hybrid fibers in HPC beams offers a material-efficient fiber utilization strategy to achieve superior flexural performance and durability.
