The Effects of Single and Hybrid Polypropylene Fibers on the Workability and Residual Strength Properties of Concrete Road Pavements Against Freeze-Thaw Cycles

This study mainly examines the slump, mass loss (ML), abrasion loss (AL), residual compressive strength (RCS), and residual splitting tensile strength (RSTS) of concrete reinforced with micro- and macro-polypropylene (PP) fibers after the F-T process. In the blends, micro- and macro-PP fibers were added to the blends at 0.3%, 0.6%, and 1% by volume. In total, 25, 50, 100, and 150 F-T cycles were applied to all samples. The study's results show that micro- and macro-PP fibers negatively affect the blends' slump values. Besides, PP fibers did not contribute to reducing the ML values of the samples after the F-T process. Moreover, the contribution of the PP fibers in prohibiting the decrease in RCS capacities of specimens after the F-T process is valid up to 0.3% volumetric fiber content. Additionally, PP fibers were more efficient in hindering reductions in AL and RSTS capacities after the F-T process of the specimens. Furthermore, using macro-PP fibers in hybrid form with micro-PP fibers reduced AL and improved RCS and RSTS capacities more than single macro-PP fibers. After 150 F-T processes, the reduction in AL of C0 control concrete was 9.41%, while the declines in AL of C1-C6 samples ranged from 7.56% to 8.92%. In addition, after 150 F-T processes, the decrease in RCS and RSTS loss of C0 control concrete is 25.09% and 28.30%. In contrast, the decline in RCS and RSTS loss of C1-C6 samples varies between 22.94-32.97% and 20.10-25.75%, respectively.