Strength Comparison Between Plain Concrete and Human Hair Fiber Reinforced Concrete

This experimental study compares the strength performance of Plain Concrete (PC) and Human Hair Fiber Reinforced Concrete (HHFRC). M20 grade concrete mixes were prepared with human hair fiber contents of 0%, 0.4%, 0.8%, and 1.6% by weight of cement while maintaining a constant water–cement ratio of 0.45. Standard cubes, cylinder, and beam specimens were cast, water cured, and tested at curing ages of 7, 14, and 28 days. Workability was evaluated using the slump test, and mechanical properties were assessed through compressive strength, split tensile strength, and flexural strength tests in accordance with relevant Indian Standard codes. The results showed a consistent reduction in workability with increasing fiber content due to fiber interlocking and reduced flowability. Concrete containing 0.4% human hair fiber exhibited optimum performance, achieving a maximum 28-day compressive strength of 24.64 MPa, flexural strength of 5.01 MPa, and significantly improved tensile strength, with split tensile strength reaching 3.39 MPa compared to plain concrete. The inclusion of human hair fibers effectively controlled micro-crack propagation, enhanced tensile resistance, and improved post-cracking behavior. Higher fiber contents of 0.8% and 1.6% resulted in strength reduction due to poor workability and fiber clustering. Although lower strength values were observed at 14 days due to cold weather curing conditions, adequate curing ensured satisfactory strength development at 28 days. The study concludes that human hair fiber can be effectively utilized as a sustainable and low-cost reinforcement in concrete, with an optimum dosage of 0.4% by weight of cement recommended for crack-resistant and tensile-strength-enhanced applications.