Avaliação da consistência de solo laterítico com adição de fibra de polipropileno

Abstract

Lateritic soils, widely distributed throughout Brazil, are fundamental materials for civil infrastructure but often exhibit high plasticity and susceptibility to shrinkage, which compromise their volumetric stability. The search for sustainable improvement alternatives has encouraged the use of synthetic fibers as substitutes for conventional stabilizers such as cement and lime, which are associated with high carbon emissions. This study aimed to evaluate the influence of polypropylene fiber addition on the consistency limits of a lateritic soil from the municipality of Toledo, Paraná State, in order to understand its physical behavior under moisture variation. Tests of particle specific gravity and Atterberg limits—Liquid Limit (LL), Plastic Limit (PL), and Shrinkage Limit (SL)—were conducted on undisturbed soil samples containing fiber contents of 0%, 0.5%, and 1.0%, following the corresponding ABNT standards. The results indicated an average particle specific gravity of 2.65 g/cm³, consistent with soils derived from basaltic rocks. The addition of polypropylene fibers increased the liquid and plastic limits, from 46.87% and 40.50% (natural soil) to 62.18% and 34.95% (soil with 1.0% fiber), reflecting greater moisture retention capacity and deformability. Although the consistency index decreased from 2.02 to 1.03, the material exhibited more ductile behavior and reduced susceptibility to cracking, making it suitable for geotechnical applications that require controlled flexibility, such as reinforcement of pavement layers, embankments, and slopes. It is concluded that the incorporation of polypropylene fibers represents a technically and environmentally sustainable alternative for the physical improvement of lateritic soils, contributing to the development of more durable and environmentally responsible geotechnical solutions.