Study On The Use Of Facemask Fibers For Soil Reinforcement

Abstract

This study investigated the potential application of facemask materials as a sustainable solution for soil reinforcement, with a focus on assessing the influence of facemask fiber attributes on the geotechnical properties of Fiber-Reinforced Soils (FRS). After conducting interface shear tests and tensile strength tests on facemask materials, CUIC triaxial tests were performed on a raw soil and corresponding FRS specimens, incorporating various facemask fiber configurations and geotextile materials for comparison purposes. Results of study indicate that the inclusion of facemask fibers can indeed influence the magnitudes of FRS cohesion and friction angle relative to raw soil values, leading to an increase in the soil shear strength. Specimens with 2.5 x 51 mm-long fibers at a concentration of 1.2 kg/m3 led to the greatest strength increase measured in this study, with a total shear strength increase of 39.7%. This performance was followed by that of 5.1 mm-wide and 51 mm-long fibers at 0.8 kg/m3, resulting in a 31.3% improvement in shear strength. Proper addition of facemask fibers with even spread and random orientation in the soil consistently led to increased shear strength in FRS specimens. This increase was evident not only in the overall toughness of the specimens but also in the effective friction angle, showing an improvement of up to 18%. However, it was observed that effective cohesion remained practically unchanged or, in some cases, decreased by as much as 82%. Additionally, the findings indicate that thinner fibers tend to be more effective in the reinforcement process, and the optimal concentration of facemask fibers is closely associated with their aspect ratio.