The use of human hair as a fiber reinforcement in construction of concrete

In the last two decades, the increase in quality and strength in new concrete technology has grown significantly. One of the new generation concretes that is considered as a powerful and efficient concrete in the construction industry today is fiber concrete, which has improved mechanical properties such as higher tensile strength and even improved compressive strength. This concrete, which has a compressive strength in a range of 15 to 200 MPa, is mainly used in the construction of structures resistant to dynamic loads and thin walls, and its use in new construction projects has a high potential. In the present study, the role of human hair as fibers in reinforcing concrete and the characteristics of hardened concrete have been investigated and its details have been studied from the point of view of mechanical characteristics. For this purpose, 6 types of mixing schemes with different percentages of crushed hair (0-1-2-3-4 and 5% by volume) were considered and the desired mixtures were reached and molded with the help of lubricant. Tests of compressive strength, tensile strength, modulus of elasticity, and water absorption were performed to evaluate the mechanical and physical properties of concrete. The results of compressive strength of the samples showed that 2% of the consumed hair caused a 9.8% increase in compressive strength compared to the control design. Tensile strength also increased by 34.3% in the same percentage of consumption compared to the control design. The modulus of elasticity increased by 8.65% in 1% of hair consumed and then decreased. Water absorption had an increasing trend and in 2% consumption, showed a 24.2% increase compared to the control.