Assessing Novel Fiber Reinforcement Against Conventional Mix by Using Both Natural and Synthetic Fibers in Concrete with Statistical Performance Analysis

Abstract

This research investigates the effect of incorporating innovative human hair fibers (HHF) and polypropylene fibers (PPF) into concrete, which has been observed to enhance the material’s strength characteristics. These fibers augment the concrete’s tensile strength and resilience, fortifying it against cracks and elevating its overall endurance. This research delves into the impact of reinforcing concrete specimens with human hair and polypropylene fibers. These specimens are employed in cube, cylinder and flexural beam tests. Both fresh and hardened properties, such as compaction factor and slump, and compressive, split-tensile, and flexural strength at varying curing periods (28 days and 90 days) and the ratios (1%, 2%, and 3%) are considered by weight of cement. Specifically, the 3% polypropylene fiber concrete mix exhibited the highest average compressive strength at both 28 and 90 days, while the 2% polypropylene fiber mix showed the highest split-tensile strength. Flexural strength results followed a similar trend. Results show that 3% HHF addition leads to notable improvements in concrete strength properties, albeit not as significant as with polypropylene fibers. Statistical analysis, including independent samples Kruskal–Wallis tests, was conducted to compare the distributions of strength values across different groups. The statistical analysis indicates significant differences in strength distributions across groups, with p-values below the significance level of 0.05. This underscores HHF’s potential as a sustainable alternative in construction applications, contributing to enhanced concrete strength.