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Permanent deformation is associated with wheel track rutting (WTR) and is one of the main causes of defects in the pavements of Brazilian highways. Seeking to mitigate this situation, this paper presents a study about the permanent deformation of three typical subgrade soils of the Santa Maria region, Rio Grande do Sul (RS), located in the southern region of Brazil. In addition to the physical, chemical, and mechanical characterization of the materials, this research presents results from repeated load triaxial tests to obtain the resilient modulus (RM) and the permanent deformation (PD) parameters. The Compound model of the resilient modulus, posteriorly cited on the Petrobras Asphalt Thematic Network Project, showed the best results. The permanent deformation tests were conducted using a frequency of 2 Hz and 150,000 load application cycles and posteriorly adjusted to the Guimaraes Model, of which average statistical correlation was 0.91. However, the predominance of fine materials combined with low compaction energy resulted in high deformation rates and the occurrence of shakedown in domains: A (plastic shakedown), B (plastic creep) and C (incremental collapse).

The compression index, swelling index and preconsolidation stress values are essential for reliable settlement calculations. However, it is a challenge to obtain representative parameters for very soft, organic, high-plasticity clays, which are often found in the Jacarepaguá Lowlands, Rio de Janeiro, Brazil. In recent decades, several geotechnical correlations have been proposed for estimating the parameters to check oedometer test data. The compression index can be estimated based on simple laboratory index tests and the preconsolidation stress can be found by means of piezocone and vane tests. In this paper, data from 24 different investigation clusters located in the region are analysed. Undisturbed samples were collected from 20 different locations; 67 piezocone tests and 48 vane tests were carried out, which resulted in a comprehensive data bank. Then correlations were developed and compared with a number of equations to assess their reliability. Special emphasis was given to correlations between the compression index and soil water content, and also between the preconsolidation stress and the corrected cone resistance and shoulder pore pressure measured in the piezocone tests.

RESUMO A escassez dos recursos naturais e a demanda por alternativas de reutilização de materiais tornou a reciclagem uma palavra de ordem no atual cenário da construção rodoviária mundial. A fresagem de pavimentos produz um material de alto valor econômico e com ótimas propriedades físicas e mecânicas que podem ser introduzidas na composição de novas misturas asfálticas. O presente trabalho avaliou o comportamento mecânico de misturas usinadas a quente com adição de diferentes teores de ligante novo, de 2,5% a 4,5%. O material de estudo é proveniente da Rodovia Brasileira 290 (BR-290), do trecho situado entre os municípios de Rosário do Sul e São Gabriel, no estado do Rio Grande do Sul (RS). Para caracterização do material fresado foram realizados os ensaios de granulometria, extração de betume, estabilidade e fluência Marshall e resistência à tração por compressão diametral com corpos de prova cilíndricos moldados conforme as misturas propostas. De acordo com os resultados, obtiveram-se valores de estabilidade, fluência e resistência à tração por compressão diametral satisfatórios para a aplicação de material fresado (50% e 100% de adição) em misturas asfálticas para camadas de rolamento. Portanto, a reutilização desse material, nas proporções avaliadas, proveniente do próprio pavimento, além de atender as especificações técnicas, também surge como solução para evitar deposição inadequada do mesmo, reduzindo o passivo ambiental. ABSTRACT The scarcity of natural resources and the demand for alternative reuse of materials has made recycling a slogan in the current scenario of global road construction. A floor milling (Recycled Asphalt Pavement – RAP) yields a material with high economic value and excellent physical and mechanical properties that may be introduced in the composition of new asphalt mixtures, from 2.5% to 4.5%. This study evaluated the mechanical mixtures machined hot with addition of different amounts of new binder behavior. The study material comes from the Brazilian Highway 290 (BR-290), passage located between the municipalities of Rosario do Sul and São Gabriel, in the state of Rio Grande do Sul (RS). For characterization of the milled material was performed assays grading, bitumen extraction, Marshall stability and creep and tensile strength by diametral-compression proof bodies of cylindrical specimens molded in accordance with the proposals mixtures. According to the results, we obtained values of stability, creep and tensile strength by diametral compression, suitable for the application of milled material (50% and 100% addition) in asphalt mixtures for layers bearing. Therefore, the reuse of this material, in the proportions evaluated, from the pavement itself, in addition to meeting the technical specifications, also appears as a solution for the avoid inadequate deposition of the same, reducing environmental passive.