Natural fibers and the potential of babassu coconut in soil reinforcement: A review

Improvement of the soil's properties in order to resist erosion is desirable, and soil reinforcement is one of the techniques used to achieve this. The incorporation of natural fibers into the soil to form a composite material has been widely investigated. The most common natural fibers used for soil reinforcement are green coconut, sisal, and jute fibers, which were the subject of the systematic review carried out in this study. The study also presented babassu coconut as a potential material for soil reinforcement. Using the methodology adopted, 76 publications related to the theme were selected and studied. This study made use of the Periodicals Portal virtual library and the articles selected were limited to peer-reviewed articles published between 2008 and 2019 in either Portuguese or English. The references of the selected articles were also analyzed. The data from the selected publications were analyzed and described under the following discussion topics: natural fibers in soil reinforcement (green coconut, sisal and jute), ideal fiber length and content for soil reinforcement, correlation between fiber content and ideal length, aspects of babassu, and future perspectives for the use of babassu. It was concluded that the natural fibers increase the mechanical properties of the soil and that the babassu husk fiber also has potential to improve the soil. It is necessary to investigate, among other characteristics, the ideal fiber length and content for the principal types of soil found in the northeast region, as well as to evaluate the effect of saturation and durability over time.