Geotechnical Behavior and Soil-Fiber Interaction of Clayey Soil Mixed with Randomly Dispersed Coconut Fibers

A.I. Oliveira Júnior, J.F.T. Jucá, J.A. Ferreira, L.C. Guilherme

Article

Soils and Rocks, São Paulo, 42(2): 127-138, May-August, 2019 | PDF


Abstract

This study aims to experimentally analyze the influence of the addition of different amounts of short coconut fibers on the geotechnical properties of tropical clay soil. Samples with 0, 0.5, 1, and 2 wt% of fiber in regard to the dry weight of soil were analyzed. Compaction, direct shear, compressibility, hydraulic conductivity, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) tests were performed on samples. The best results for the direct shear test were presented by the sample with 1 wt% of fiber. For the compressibility, the results improved proportionally to the added content of coconut fiber. Samples with less than 1 wt% did not show any significant changes in the hydraulic conductivity test; the hydraulic conductivity remained of the order of magnitude of 10-7 cm/s. The SEM and EDS analyses revealed the existence of bonds between the particles of clay and coconut fibers surface. The geotechnical behavior of the mixes with 0.5 and 1 wt% was improved because of this bond between the matrix and reinforcement phase.


Submitted on June 22, 2018; Final Acceptance on July 8, 2019; Discussion open until December 31, 2019. DOI: 10.28927/SR.422127