INFLUENCE OF MOISTURE CONTENT ON THE TEST OF RESILIENCE MODULES IN BR-319/AM AND BR-156/AP SUBGRADE SOILS FOR APPLICABILITY IN PAVEMENT
Resilient Modulus; BR-319/AM; BR-156/AP; Moisture content; Tropical soils; MCT; Pavement.
During the useful life of the pavement, variations in moisture occur due to environmental factors, influencing the support capacity and the resilience modulus of the materials. The main objective of this research is to evaluate the influence of moisture on the resilience modulus, adopting the compaction moisture variations of +2% and -2% in relation to the optimum humidity. The research includes 19 soils located on BR-319/AM and BR-156/AP, for different applications. The granulometry tests by sedimentation, Atterberg limits, real grain density, miniature compaction, and mass loss by immersion (the latter two being used for the MCT classification) were carried out, as well as the resilience modulus test. For the concentrated loan soils, stabilized with lime, in addition to these, the lime content estimation test was also carried out by the pH method and the expandability test. The results obtained for the BR-319/AM soils showed that they are fine soils, classified as NG', with a high mass loss by immersion and an average reduction of 55.8% in the resilience modulus, with the addition of 2% of moisture. The chemical stabilization of the soil with lime proved to be promising, reducing the expansibility and the negative effect of water on the soil. The BR-156/AP soils showed a lateritic behavior, where a 2% increase in moisture reduced the material's resilient behavior by around 30%. Among the three evaluated models, the composite model used in the National Dimensioning Method (MeDiNa) was the most adequate, regardless of moisture content.
moisture variations during compaction have shown to considerably reduce the resilience modulus of all studied soils. The present work contributes to the understanding of soils in the northern region of the country and reinforces the deepening of the understanding of the variation of moisture in the mechanical performance of pavements.