Effect of Freezing-Thawing on Clayey Soils Reinforced with Human Hair Fibers

The study conducted by Necmi Yarbaşi found that reinforcing clayey soil with human hair fibers (HHF) improved the soil's unconfined compressive strength (UCS) both before and after freezing-thawing cycles. The addition of HHF in mass ratios of 0.5%, 1%, 1.5%, and 2% by dry weight resulted in UCS increases of 14-54% before freezing-thawing and 7-49% after, with the most notable improvements observed with the 1.5% HHF mixture. The research concluded that HHF is a beneficial reinforcement for clayey soils in cold climates due to its strength enhancement, ductility maintenance, pH reduction, and resistance to biodegradation, offering an environmentally friendly and cost-effective solution. However, the number of samples or replicates used in the study was not specified.