Author(s): María Fernanda Quispe Delgado and Juan Carlos Paredes Rivas

Abstract: This study presents an integrated experimental and numerical investigation into the flexural behaviour of hybrid fiber-reinforced concrete (HFRC) beams incorporating steel and polypropylene fibers. The research aimed to evaluate the synergistic effects of multi-scale fiber reinforcement on crack control, ductility, stiffness, and ultimate flexural capacity. Concrete beams with various fiber combinations were prepared and tested under four-point bending to determine cracking load, yield load, ultimate load, load-deflection characteristics, stiffness degradation, and toughness indices. The experimental findings revealed that hybrid fiber composites exhibited superior mechanical performance compared to plain and single-fiber concretes. Specifically, beams containing 1.0-1.5% total fiber content with a steel-to-polypropylene ratio of 3:1 demonstrated significant increases in cracking resistance, flexural strength, and ductility, accompanied by a more gradual post-peak response. Statistical analysis through one-way ANOVA confirmed the influence of hybridization as a key factor affecting flexural performance. Complementary finite element (FE) simulations, conducted using the concrete damage plasticity model, accurately predicted load-deflection responses with mean absolute percentage error below 10%, validating the model’s reliability for performance-based design applications. The study concludes that the combination of steel and polypropylene fibers not only enhances strength and energy absorption but also improves serviceability and structural resilience. Practical recommendations include the adoption of hybrid fiber mixes for beams, slabs, and bridge decks where enhanced ductility and crack control are critical. The validated FE framework also provides a useful design tool for predicting HFRC flexural behaviour in advanced structural modeling and optimization.

Pages: 37-42 | Views: 4 | Downloads: 2

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