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.