Infiltration characteristics of natural fiber reinforced soil

The use of natural fibers in civil engineering applications has gained popularity due to the present-day need of alternate sustainable materials in contrast to conventional petroleum based synthetic fibers. Randomly distributed fiber reinforced soil (RDFS) using natural fibers has been extensively studied with respect to their mechanical properties. However, these soil-fiber composites are exposed to cycles of precipitation in the field when employed for erosion protection and embankment stabilization. Infiltration rate of a soil-fiber composite consequently becomes an important parameter to design geotechnical infrastructures (such as road embankments, rural subgrade, etc.) and predict run-off along with soil erosion behavior. The infiltration process in soil-fiber composites has rarely been investigated through a controlled laboratory study. This study investigates the infiltration rate in compacted natural fiber reinforced soil composite. Laboratory investigation using mini disk infiltrometer (MDI) was conducted to compare the infiltration rate in soil-fiber composite reinforced with three natural fibers. Jute, coir and water hyacinth fibers of same aspect ratio were used to reinforce soil at three different fiber percentages at varying densities. It is observed for all the cases that the infiltration rate increases for all soil-fiber composite as compared to bare soil. This increase is attributed to preferential flow along the fibers in case of the composites. The effect of composite density and fiber type on the alteration of infiltration rate is discussed. It is observed that the surface morphology and type of filament arrangement also influences infiltration in such composites.