Alfa Fiber Reinforcement in Recycled Polymer Concrete: Mechanical Performance and Fracture Analysis

This work presents an experimental approach for the development and characterization of a polymer concrete made from recycled polypropylene (PP) and sand. Two other types of polymer concrete reinforced with 1% short Alfa fibers and 1% short E-glass fibers, respectively, were also prepared using an extruder. Semi-circular bend (SCB) tests were performed to evaluate the influence of fiber type on fracture toughness. The results indicate that Alfa fiber reinforcement improves the fracture performance of the polymer concrete. The composite reinforced with Alfa fibers showed the highest measured fracture toughness, with an average value of 0.81 ± 0.05 MPa√m, compared to 0.71 ± 0.09 MPa√m for glass fibers and 0.71 ± 0.05 MPa√m for the unreinforced samples. The SEM observations suggest differences in fiber–matrix interaction that may contribute to the observed fracture response. Overall, Alfa fibers show promising potential as a sustainable reinforcement for recycled polymer concrete.