Effects of Human Hair and Waste Tyre Rubber Fibers on Concrete

Concrete is mainly used in cases where we need to resist compressive forces as concrete is stronger in compression but relatively weaker in tension. This weakness in concrete can be mitigated by using fibres as reinforcement in the concrete mix. Waste materials in the form of human hair and tyre rubber cause environmental pollution. Hair and waste tyre rubber can be recycled and used effectively in the concrete as reinforcement in fibre form. In this work first human hair content viz., 0%, 1.5% & 3%, by weight of cement for M30 grade concrete were studied by determining the strength properties (compressive, tensile and flexural strength) at3, 7 and 28 days, respectively. The trends showed that there is significant increase in compressive strength (4.9 %) at around 1.5% human hair content which then shows a decreasing trend (~ 2.4% at 3% human hair content) on further increase in human hair content. Then an approximate optimum percentage of human hair content (~ 1.5% by weight of cement in this study) that yielded better mechanical properties namely, compressive, tensile and flexural strength than the conventional concrete (control mix) has been chosen. Human hair content of 1.5 % by weight of cement is mixed with different rubber content of 1.5 %, 3% and 4.5 % by volume of concrete to study the mechanical properties of the concrete at 3,7 days and 28 days. By testing of cubes, beams and cylinders, a significant increase in flexural strength (~8.9 % increase) and tensile strength (~5.7% increase) of concrete was observed due to the addition of human hair and tyre rubber as fibre reinforcement. However there is a decrease in compressive strength though not so much significant (~2% decrease).