Enhancing cement concrete strength by incorporating synthetic human hair waste as fibre: The case of Musanze District in Rwanda

Abstract

This study examined the use of synthetic human hair waste as reinforcement in concrete to improve its mechanical properties to mitigate micro-cracking. Specifically, the research evaluated the effect of fibre inclusion on concrete workability, compared the compressive strength of conventional concrete with fibre-reinforced concrete, and determined the optimal fibre content required to achieve improved overall performance in terms of both strength and workability. The experiments, including sieve analysis, slump test and compressive strength test, were conducted according to IS 383-1970, American standard ASTM C143 and IS 456:2000, respectively. The study incorporated synthetic human hair waste into concrete at various percentages, ranging from 0% to 4.5% by weight of the cement for the slump test, and from 0% to 3% for the compressive strength test. The results showed that the addition of fibres slightly improved the workability of concrete, with slump values increasing from 5.2 cm to 5.8 cm up to 3% fibre content, before slightly decreasing at 4.5%. In terms of mechanical performance, 1.5% synthetic human hair waste fibres significantly enhanced compressive strength by 16.56% at 7 days and 27.23% at 28 days, whereas a higher content (3%) caused a notable reduction in strength. Therefore, 1.5% fibre content was identified as the optimal proportion for improving concrete performance. This study recommended that synthetic human hair waste fibre can be incorporated at an optimal dosage of 1.5% by weight of cement to enhance the mechanical performance and strength characteristics of concrete, as higher fibre contents negatively affect compressive strength. Further studies are required to evaluate long-term durability and to establish its practical applicability in sustainable construction.