Evaluating the performance of human hair impregnated with cement slurry in remediation of the Caspian coastal silty sand

Abstract

Construction of various civil structures on problematic soils with weak or soft density is associated with many hazards. Such soils are prone to asymmetric subsidence caused by poor shear strength and high compressibility. Silica sand in the Caspian coast are mainly exposed to river sediments or absorbent sewage leachate of the urban and residential areas, and the presence of these materials in the soil environment weakens their strength parameters. Generally in the remediation of problematic soils, a variety of methods have been developed, including the use of bearing elements or remediation and modification of soil physical characteristics. In this study, for remediation of this type of sandy soils, the Human Hair Fibers (HHF) are used, which have considerable advantages in terms of tensile strength and compatibility with environmental conditions compared to other natural and synthetic fibers. The effect of adding different contents of natural human hair fibers as impregnated and non-impregnated fibers to cement slurry at different soil relative densities shows that the addition of this type of natural fibers in both cases has improved the soil undrain compressive strength, increased the failure strain and initial Young’s modulus, and also reduced the post-failure strength loss and increased the residual soil strength.