Use of Human Hair as Natural Fibre in Fibre Reinforced Concrete

Abstract

Reinforced Concrete (FRC), offering practical and cost-effective solutions to mitigate microcracks and related structural deficiencies. This study explores the utilization of naturally abundant chopped human hair (HH) as a reinforcing fiber in concrete, given its non-biodegradable nature. The research seeks to determine the effects of human hair on mechanical properties of concrete such compressive, tensile and flexural strength as well as to investigate the mitigation and control of micro cracking through Scanning Electron Microscopy (SEM) analysis. Comprehensive tests, including compressive, tensile, and flexural strength evaluations at 7 and 28 days, corroborate the efficacy of HH fiber reinforcement in achieving desired concrete properties, as envisaged and planned. Human hair fibers were incorporated in concrete with varying percentages i-e 1%, 1.5%, 2%, 2.5% and 3% by weight of cement. The study concludes that the incorporation of human hair fibers into concrete significantly enhances its mechanical properties. Specifically, at 28 days strength, there is an observed increase in compressive strength by 18%, tensile strength by 24%, and flexural strength by 31%. The study identifies an optimum HHFs content of 2.5% for maximizing the mechanical properties of concrete. Beyond this concentration, there is a notable reduction in compressive, tensile, and flexural strength. The incorporation of human hair also led to the formation of fewer and finer cracks within the concrete matrix due to bridging effect of human hair within the cracks, effectively controlling the propagation of micro cracks and promoting localized stress redistribution. Consequently, this research not only establishes the viability of HH fibers as a reinforcement material but also underscores their potential to enhance concrete performance while mitigating costs and disposal challenges.