Caracterização e estabilização do massapê com areia para avaliação preliminar do seu uso como camada de subleito de pavimento rodoviário

Abstract

The adoption of a mechanistic-empirical method for sizing asphalt pavements, by the National Department of Transport Infrastructure (DNIT), constitutes a large advance to Brazil. However, the National Sizing Method (MeDina), made official in 2020, demands, among other requirements, dynamic testing of the Resilience (MR) and Permanent Deformation (DP) for soils that, in stabilization studies and dosing of different mixtures, can lead to an extensive experimental campaign. The tests of MR that are carried out in triplicate, together with the DP that use, at least, six test bodies (CP) to cover six different tension pairs, require in these studies nine CP for each content of stabilizing material or mixture component. This way, a preliminary characterization to determine promising mixtures, involving testing conventional, you can configure a consistent strategy in the search for the optimization of these Dynamic essays. In the present study, eleven mixtures were characterized between Massapê, expansive soil typical of the state of Bahia, and commercial sand. This characterization consisted in particle size analysis, consistency limits, California Support Index (ISC or CBR), expansion, simple compressive strength, tensile strength, sand equivalent and expansion pressure. The results indicated that the addition of sand to Massapê provided increase in maximum dry specific mass, CBR and sand equivalent values, as well as reduction in optimal moisture content, consistency indices, expansion (free and with overload) and expansion pressure. The results also indicated that the mixtures containing 60%, 70% and 80% sand proved promising for stabilizing the Massapê to acceptable expansion levels for use as subgrade, allowing directing and optimizing the experimental campaign with MR and DP tests required in MeDiNa.