A review of physio-biochemical properties of natural fibers and their application in soil reinforcement

The use of natural materials in place of synthetic materials has been the focus of research in sustainable geotechnics. In this context, use of natural plants/weeds as randomly distributed fiber-reinforced soil (RDFS) is extensively researched as a possible soil-improvement technique. The behavior of soil-natural fiber composite is dependent on the biochemical, physical, and mechanical properties of natural fibers. These natural-fiber properties are inherently different from those of conventional synthetic fibers, in which mechanical properties essentially govern the soil-fiber composite behavior. Very few geotechnical applications using natural geo-reinforcement materials have taken into consideration the biochemical and physical properties of the fiber. Moreover, there is rarely any systematic assessment and compilation of the work encompassing the application of natural fibers in soil reinforcement. This review summarizes the use of natural fibers in soil reinforcement. The study explores the importance and impact of natural-fiber properties on the performance of natural fibers in subsoil conditions. The treatment methodologies used in natural fibers to increase their longevity and reinforcement capabilities are also discussed. Based on this review, some key research gaps and the future scope of research have been highlighted. The review strongly recommends potential natural flora as RDFS fibers from a sustainability perspective. The review brings out the importance of biochemical composition (cellulose, lignin, hemicellulose, etc.) on fiber performance in subsoil conditions and highlights the use of treatment methodologies for fibers.