Abstract

Concrete, a widely used building material, has seen significant interest in the incorporation of hybrid fibers for reinforcement, offering advantages over mono fiber reinforced concrete. This study investigates the mechanical and dynamic properties of hybrid fiber reinforced concrete (HFRC) through experimental research. Mechanical parameters such as compressive strength, split tensile strength, and flexural strength were assessed for various mixtures containing steel and polypropylene (PP) fibers at different volume fractions of 0.25%, 0.5%, and 0.75%. Additionally, dynamic properties including mode shape, fundamental frequency, and damping ratio were evaluated to assess HFRC's damage resistance capabilities. Results indicate that the addition of steel and PP fibers enhances the concrete's mechanical properties, with optimal performance observed at a fiber volume fraction of 0.5%. A specific combination of 0.25% total fiber volume with 75% steel and 25% PP fibers exhibited superior performance. The study also found that the natural frequency of HFRC specimens decreases with increasing fiber content and structural damage, while the damping ratio increases. Numerical modeling using ANSYS software was employed to compare experimental results with analytical predictions. The HFRC with a total fiber volume of 0.75% and a composition of 75% steel and 25% PP fibers demonstrated the best damping qualities.