The rapid degradation of concrete structures in high-exposure surroundings has highlighted the need for advanced materials capable of enhancing both mechanical performance and durability. This review investigates the efficacy of polypropylene (PP) microfibers and macrofibers as a cost-effective and technically promising additive in M40 and M50 grade concrete, with an emphasis on flexural and compressive strength enhancement, crack pattern mitigation, and thermal resistance. Unlike conventional research that explores fiber dosages below 2%, this paper focuses on underexplored fiber percentages of 2.25%, 2.75%, 3.25%, and 3.5%—aiming to assess their performance in both moderate and severe exposure scenarios. A novel premixing technique using water dispersion is also proposed to eliminate fibre agglomeration and ensure homogeneity. Drawing on more than 50 peer-reviewed studies, this review synthesizes current literature, critically compares PP fibers with steel and basalt counterparts, and identifies significant gaps in dosage optimization, workability trade-offs, and long-term behaviour in aggressive environments. The paper concludes with a proposed experimental roadmap and outlines future research directions to establish polypropylene microfibers as a sustainable reinforcement option in high-grade concretes tailored for infrastructure longevity.
Rawal et al. (Wed,) studied this question.