Análise do comportamento mecânico de um solo reforçado com fibra de coco

Abstract

This research addresses an experimental study with coir fibre as material as a reinforcement of a recurrent silty sandy soil in the Metropolitan Region of Salvador. The fibers used do not have a predefined length, and a gravimetric analysis is carried out to identify the most common intervals of reinforcement lengths. The experimental program consisted of inserting fibrous material at concentrations of 0; 0.5; 1.0 and 1.5% in relation to the dry weight of soil. Compaction, California Bearing Ratio and Triaxial tests CD were carried out at three confining stresses (50, 100 and 200 kPa), and the content that promoted the greatest gains in the deviator stress (1.0%) was identified. After the definition of this content, a new stage of tests was carried out, treating the fibers with the hornification and mercerization technique. It was noted that the fibers treated with the hornification technique promoted greater gains in the deviator stress when compared to the untreated fibers. The treatment of the fibers by the mercerization method, on the other hand, reduced the strength of the composite in relation to the untreated fiber. Finally, with the experimental results, a semi-empirical model for fiber reinforced soils, proposed by Machado et al. (2022), which predicts the maximum deviatoric stress of the reinforced soil, was tested. The constitutive model of Machado, Carvalho e Vilar (2002) modified for soil-fiber was also applied to simulate the stress-strain behavior and volumetric strain vs axial strain. The results indicate the good adherence between the experimental results and the simulations in the two tested models, proving the good predictive capacity of these models.