Assessment of Fresh and Hardened Properties of Concrete Containing Polypropylene Fibers

Abstract

This study examines the influence of polypropylene fibers on the performance of fresh and hardened concrete. Incorporating polypropylene fibers enhances concrete properties by mitigating crack initiation and propagation, which subsequently decreases permeability and improves durability. The objective of this research was to evaluate the effects of polypropylene fiber addition at varying dosages of 0.05%, 0.15%, 0.25%, and 0.35% by weight of concrete. Experimental investigations included compressive strength testing at 7 and 28 days for hardened concrete, and slump testing to assess workability in the fresh state. Findings indicated that polypropylene fiber addition reduced workability as fiber content increased. Compressive strength initially improved with fiber addition, reaching 34.3 MPa at 0.05% and a peak of 34.4 MPa at 0.15% fiber content. Beyond this dosage, compressive strength declined significantly, dropping to 28 MPa at 0.25% and 19.1 MPa at 0.35%. Based on the results, the optimum polypropylene fiber dosage for maximizing compressive strength while maintaining acceptable workability lies between 0.05% and 0.15%.