A influência da saturação pós-compactação no comportamento resiliente de dois solos do Rio Grande do Sul empregados em subleito rodoviário

Abstract

Aiming to correct one of the predominant defects on brazilian pavements, the fatigue cracking, the National Dimensioning Method was developed, extinguishing the empirical approach applied to highways so far. The new method promotes a mechanisitc analysis and requires accurate information on the properties of each material of the pavement layers, including the subgrade resilient modulus (MR), characteristic with great influence on the structure fatigue life, whose study is fundamental for the success of highways projects. In order to add knowledge regardind to MR of soils, the present paper aims to evaluate the influence of post-compaction saturation on the resilient behaviour of soils used in subgrade. For this purpose, two soils from Rio Grande do Sul were selected to be the research subject. These materials, after compaction at optimum moisture content, were left submerged in water until saturation was reached prior to testing for obtaining the MR, allowing the comparison with the values of MR presented under the optimal conditions. The methodology adopted can be used to simulate the variation in the fatigue life of an already built pavement caused by unforessen changes in the subgrade resilient behaviour if it becomes saturated, even if the structure is in accordance with the new method. This simulation was possible through MeDiNa software, which allows to estimate the increase in the percentage of the pavement cracked área when its foundation soil starts to behave differently than expected in projects.