The influence of the variation of moisture content in the materials that make up the pavement has a negative impact on its performance. This variation in humidity is caused by inefficient drainage, oscillation of the water table, infiltrations, which affect the resistance and increase the deformability. The objective of this article is to evaluate the effect of moisture variation on the behavior of soils used in pavement subgrade from tests of resilience module. The subgrade of the highway BR-290/RS located in the state of Rio Grande do Sul/Brazil was evaluated. The repeated load triaxial equipment was used to perform tests of the Resilience Module (MR), varying the moisture content of the specimens by ± 2% in relation to the optimum humidity. There was a 70% decrease in MR comparing specimens above the optimum humidity with the ideal humidity conditions. A new MR equation was proposed that considers the variation in humidity, which showed high statistical significance. The results presented showed a great influence of the moisture content in soils, showing that the present article can contribute to a better understanding of the behavior of soils and a greater discussion about the effect of moisture variation in the dimensioning of pavements.

Highways are the mode of transport used for the transportation of the majority of loads and passengers in Brazil; however, the lack of conservation of pavements has caused several economical losses to the country. Only through suitable pavement management the rehabilitation measures taken might ensure a satisfactory level of service. The present research aimed at evaluating the performance of two pavement sections of the federal highway BR-448/RS, in southern Brazil. For three years, the evolution of the pavement structural capacity and functional condition were followed in order to propose performance trends. Deflections, permanent deformations, and surface defects surveys scarcely varied and were quite low due to the thick asphalt layers used (19 cm). On the other hand, segregation of the asphalt mixture was observed when the final layer was laid. That segregation affected pavement texture, reduced tire-road friction, and caused the formation of surface water films; thus, reducing the road safety. In general, the proposed trend lines predicted quite accurately the pavement performance throughout the period evaluated and will be used in the MeDiNa software database for the creation of a new Brazilian pavement design method.