Structural behavior of eco‐friendly ferrocement beams containing expanded polystyrene aggregates and reinforced with waste plastic fibers

Abstract This study investigates the integration of polyethylene terephthalate (PET) waste fibers into concrete as a sustainable alternative because landfilling or incineration are ineffective ways to recycle this waste because these plastic materials are not recyclable. It aims to mitigate the negative impact of waste plastic by examining the flexural behavior of ferrocement beams with expanded polystyrene (EPS) beads under static loading, using waste fibers from PET. Initially, the study focused on evaluating the mechanical properties of nine mixtures in fresh and hardened states using several mix proportions. Three PET fiber volume fractions (0.5%, 0.75%, and 1%) were mixed with two replacement ratios of EPS beads (10% and 20%) to partially replace the fine aggregates. The workability was measured using the slump test, while mechanical properties for hardened samples were obtained using standard specimens for compressive strength, density, split, and flexural strength. After determining the best mixtures for casting beams, the beams were subjected to a thorough experimental analysis of the flexural performance of the suggested built‐up EPS ferrocement beams. The program examined three main factors: the inclusion of 20% EPS beads as a partial replacement for sand, the addition of PET fibers at 0.75% of the mix volume, and the substitution of conventional stirrups with welded wire mesh as shear reinforcement. The cracking load, ultimate load, deflections, failure mode, stiffness, toughness, and ductility of such beams were discussed. From the results, a notable decline in the mechanical performance of the hardened concrete was revealed due to the incorporation of EPS beads; however, the inclusion of plastic fibers provided a degree of improvement. The flexural test outcomes exhibited that the beams reinforced with wire mesh display higher peak loads (10%, 15%, 10% for three groups) and greater stiffness (68%, 48%, 36%) compared to those with stirrups. A beam with 20% EPS and reinforced with wire mesh produced a high ultimate load (41.96) that was nearest to mortar alone. The results indicated that beams with a mixture containing both EPS and PET and reinforced with wire mesh showed that PET fibers contribute to early crack resistance more effectively than EPS alone, indicating a higher cracking load (7 KN). This beam produced the narrowest cracks (0.85 mm) compared to other beams in addition to higher stiffness (4.5 KN/mm) than beams with EPS alone. Therefore, it stands out as the best overall choice for lightweight, durable applications requiring both strength and crack control.