AVALIAÇÃO DE PROPRIEDADES MECÂNICAS UM SOLO EXPANSIVO ADITIVADO COM LIGNINA KRAFT

• DOI: https://doi.org/10.22533/at.ed.152152503027

• Palavras-chave: Geotecnia, Estabilização sustentável, Propriedades mecânicas, MCT, Ensaio expedito das pastilhas

• Keywords: Geotechnics, Sustainable stabilization, Mechanical properties, MCT, Quick tablet test.

• Abstract: The expansive behavior of soils containing 2:1 clay minerals poses significant challenges for engineering projects, as this structure leads to a high water absorption capacity, resulting in volumetric deformations, instability, and susceptibility to erosion, especially in retrogressive erosion areas. Soil stabilization is a widely applied technique aimed at improving the mechanical properties and durability of natural soils for geotechnical applications. Stabilizers enhance soil cohesion and mechanical resistance, making it more suitable for load-bearing applications and more resistant to natural degradation. There is a growing demand for more sustainable alternatives to conventional additives, aiming to reduce environmental impacts. Lignin, a byproduct of cellulose production, has been investigated as a soil stabilizer, particularly in granular soils, where it forms an adhesive film that binds soil particles together. This study aimed to evaluate the stabilization of an expansive soil located in Pelotas, Brazil, using powdered Kraft lignin. To achieve this, classification tests using the Miniatura Compactada Tropical (MCT) method, the quick test with small MCT specimens, measurement of diametral contraction, and water absorption tests over a 24-hour period were conducted, in addition to dry resistance testing of spherical soil specimens. The results indicate that the addition of lignin (3% and 6%) to the fine fraction of the expansive soil has potential for stabilization. The 3% concentration exhibited the best performance, with no needle penetration after water absorption, indicating improved mechanical properties and greater moisture resistance. These findings highlight the potential of lignin as a sustainable stabilizer, improving the soil’s physicochemical properties and reducing its susceptibility to expansion.