Estudo laboratorial de um solo tropical granular estabilizado quimicamente para fins de pavimentação

• Autor(a) principal: Rocha, Mirella Talitha
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/8843
• topic: Ensaios laboratoriais; Estabilização de solos; Solo-cal; Solo-cimento; Pavimento asfáltico; Laboratory tests; Soils stabilization; Soil-lime; Soil-cement; Asphalt pavement; ENGENHARIA CIVIL::GEOTECNICA

The use of alternative materials as subbases and bases stabilization is being increasingly in asphalt pavements, especially in areas with lack of granular materials. The chemical stabilization using additives such as Portland cement and hydrated lime is used since antiquity, with the aim of improving the geotechnical characteristics of natural materials. The treated soils exhibit complex behavior, influenced by several factors such as chemical reactions, soil types, added amount of stabilizing, moisture content and the time and type of curing. Generally, the procedure for determining the minimum lime or cement content to be added to the mixture refers to the initial estimate and attempts the standard recommendations to meet the parameters of mechanical tests, in order to define a minimum additive amount present resistance compatible with the paving design. The focus of this research was initially to analyze the dosage employed in the base layer of the GO-080 highway, in the stretch between Neropolis-GO and the BR-153 where the pavement structure consists of 20 cm thick granulometrically stabilized subbase, gravel laterite base with 20 cm thick and stabilized with 20% sand, 2% Portland cement (PC II-Z-32) and asphalt concrete surface with 5 cm thick. In addition, the aim was also to study the mechanical properties of natural gravel and their behavior when mixed with three levels (2%, 4% and 6%) of cement and hydrated lime. Therefore, laboratory tests for soil characterization, compaction tests on intermediate Proctor energy, determination of expansion and California Bearing Ratio, unconfined compression and resilient modulus of the molded mixture at the optimum moisture for three times cure (0, 7 and 28 days) were carried out. The resilient moduli results were evaluated by numerical analysis using KENLAYER software. To complement the analysis of strength parameters, diffraction X-ray and scanning electron microscopy tests were performed. The results show that for the studied soil, the chemical stabilization with lime contributed little to the increase of strength parameters, but the use of cement showed greater potential use. Differences on behavior observed in unconfined compression tests and dynamic triaxial were explained by changes that occur in the microstructure during the stabilization process. Finally, it is clear that the tropical soil stabilization process is complex, with over current mechanical tests, such as dynamic triaxial, and unconventional parameters for pavement soil analysis, such as water/cement ratio and porosity, should be analyzes incorporated in order to obtain more consistent results.