Abstract
For the purpose to clarify the required performance of fibers used in the geomaterial for barrier system of coastal landfill sites that improves toughness of the brittle cement treated clay by inclusion of fibrous materials, a series of laboratory mixing tests were conducted. The effects of fiber types on mechanical and hydraulic properties of the geomaterial were examined by comparing the results from unconfined compression tests and hydraulic conductivity tests. No major differences were observed in the results that were obtained from five types of fibers; PVA, PA, PP, recycled PP and PE.