Estudo dos mecanismos de compactação em misturas entre solo arenoso e altos teores de emulsão asfáltica

Abstract

RESUMO -Este artigo apresenta uma avaliação dos mecanismos de compactação de misturas entre solo arenoso e altos teores de emulsão asfáltica. Para tanto, foram utilizados um solo classificado pelo Sistema Unificado de Classificação dos Solos como SP e uma emulsão asfáltica catiônica de ruptura lenta (RL-1C). As misturas entre solo e emulsão asfáltica foram confeccionadas com teores de emulsão entre 13% e 31%, em peso, e foram submetidas a diferentes condições de compactação, de forma que as informações obtidas permitissem a identificação dos mecanismos que governam a sua compactação, bem como a identificação da metodologia de compactação mais apropriada para este tipo de material. Os resultados mostraram que os mecanismos responsáveis pela compactação das misturas entre solo e altos teores de emulsão asfáltica são significativamente diferentes daqueles que regem a compactação dos solos granulares e finos. A rigidez do filme betuminoso apresentou-se como o parâmetro com maior influência na compactação das misturas estudadas, mostrando que para a obtenção de uma compactação eficiente é necessária a diminuição da viscosidade do ligante asfáltico, que pode ser feita pelo aumento da energia, ou aumento da temperatura do ligante no momento da compactação.ABSTRACT -This paper presents an evaluation of the mechanisms which define the compaction of mixtures between sandy soil and high asphalt emulsion contents. A sandy soil classified according to the Unified Soil Classification System as SP and a cationic asphalt emulsion slow set (RL-1C) were used. The mixtures between soil and asphalt emulsion were manufactures with asphalt emulsion contents varying from 13% to 31%, in weight, and were compacted under different conditions, in order to allow the identification of the mechanisms responsible for their compaction, and compaction methodology suitable for this material. Results show that the mechanisms governing the compaction of mixtures between soil and high asphalt emulsion contents are significantly different from those ones regarding the granular and fine soils. The stiffness of the residual asphalt binder on the soil particles presents itself as the most important factor that has influenced the compaction of the studied mixtures, indicating that to obtain an efficient compaction of the mixtures it is necessary to increase the energy used in the compaction process or decreasing the viscosity of the residual binder by heating during the compaction procedure.Palavras Chave - solo-emulsão, compactação, emulsão asfáltica.

Stabilization of sandy soil with high content of asphalt emulsion

“…Preliminary studies on the compaction of mixtures of sandy soils with high asphalt emulsion contents, 13% to 31%, in weight, have already been performed (Lima, 2016;Lima and Dantas Neto, 2019). These studies involved mixtures prepared by adding a low-breaking cationic asphalt emulsion, classified according the Brazilian standardization as RL-1C type (IPR, 2013), to a soil classified as poor graded sand (SP) and consisted of assessing the compaction energy (standard and modified Proctor) and the viscosity of the asphalt binder.…”

“…The results of the studies performed with mixtures of sandy soil with high asphalt emulsion contents also revealed that the stiffness of the formed asphalt film exerts a strong influence on the compaction process of emulsionsoil mixtures (Lima, 2016;Lima and Dantas Neto, 2019). The efficiency of the compaction was obtained only in situations where the emulsion viscosity was significantly low, or with increased compaction energy.…”

“…Instead, using the physical parameters as unit weight, void content, and void content in relation to the mineral grain structure can be used to better represent the influence of the asphalt emulsion added to the compaction characteristics of emulsionsoil mixtures. Lima (2016) and Lima and Dantas Neto (2019) also present results of scanning electronic microscopic tests carried out to verify the homogeneity of the emulsion-soil mixtures made with high asphalt emulsion contents. According to these authors, the homogeneity of the compacted mixtures improved with the increase in the asphalt emulsion content used, causing the formation of fewer lumps in the mixture.…”

“…The methodology used to compact the soil-emulsion mixtures was the Marshall procedure standardized by ASTM D6926, with the compaction made immediately and 24 hours after the mixing process of the soil with asphalt emulsion, resulting in a total of two different types of mixtures, as shown in Table 3. The compaction of the mixtures after 24 hours was done in order to ensure the complete breaking of asphalt emulsion before compaction as also proceeded in the studies of Lima (2016) and Lima and Dantas Neto (2019). Figure 1 presents the compaction curves showing the variation in unit weight of the mixtures with the asphalt emulsion content used.…”

Avaliação do comportamento cisalhante de misturas solo-emulsão com teores de emulsão variando de 16% a 28% em massa

“…Os estudos de misturas solo-emulsão em outras áreas da Geotecnia ainda são muito incipientes, destacando-se algumas aplicações para uso na construção de barragens de terra como os trabalhos JACINTHO [5], LIMA [6], PEREIRA [7], LIMA e DANTAS NETO [8], BRITO [9], DANTAS NETO et al [10] e BRITO et al [11].…”