Effect of Single and Hybrid Incorporation of Steel, Polypropylene, and Pet Fibers on the Properties of Concrete Under Static and Impact Loading

Abstract

In this paper, the effect of single and hybrid use of steel fibers (STF), polypropylene fibers (PPF), and PET fibers (PETF) on the static and impact properties of concrete was comprehensively evaluated. Concretes were evaluated and compared according to different properties, including static properties (unit weight, compressive strength, flexural strength, splitting tensile strength, fracture energy, and flexural toughness), microstructural properties, impact performance, and cost. In addition, the overall performances of the tested mixtures were comparatively assessed using the desirability function (DF) analysis. The performed tests and analyses showed that while STF had a positive effect on the compressive strength of concrete, PPF and PETF had a negative effect. On the other hand, fibers, especially STF, remarkably increased the splitting tensile strength, flexural strength, flexural toughness, fracture energy, and impact performance of concrete. It was found that under static and impact loads, fibers were successful at shifting the brittle behavior of concrete into a more ductile one. Scanning electron microscopy (SEM) analysis revealed that STF had a better adherence with the surrounding cement paste than PPF and PETF. It was concluded from the DF analysis that concrete containing %1 STF showed the best overall performance among all the tested concrete mixtures. © 2025 ICE Publishing. All rights reserved.