Initial assessment of permeability and mechanical properties of NRL-treated recycled wool geomembranes

Geomembrane materials, predominantly composed of synthetic polymers, are extensively utilised as hydraulic barriers but pose ecological concerns. Although natural materials have been employed in a variety of geosynthetic applications, their use in geomembranes remains unexplored. This study explores the novel possibility of employing recycled wool fabric, surface-coated with natural rubber latex (NRL), as an environmentally friendly impermeable material for hydraulic constructions. The objective of the NRL coating was to improve the wool fabric's strength and impermeability. The wool fabric was treated by spraying it with NRL at different concentrations and immersing it in NRL. NRL treatment significantly enhanced the tensile properties of the fabric, increasing machine-direction strength by 225%–253%. Overall, the treated fabrics showed one to three times higher tensile strength in both machine and cross-machine directions than the untreated fabric. The fabric becomes impermeable after NRL treatment. The pullout and direct shear tests indicated that the untreated fabric exhibited higher interface friction and pullout resistance than the NRL-treated fabrics due to its rougher surface characteristics. Nevertheless, the interface properties of the treated fabrics remained within the desired range, demonstrating their suitability for geotechnical applications.