Avaliação mecânica de misturas asfálticas usuais em revestimentos regionais

Abstract

There is a major concern on the global stage with the scarcity of natural resources and global warming. In this context, the paving has been looking for alternatives aimed at reducing fuel consumption and the consequent reduction of the emission of greenhouse gases, highlighting the use of warm mixtures as an option. In the local scenario, the urban roads of the city of Manaus / AM show historically premature deterioration, instigating the evaluation of regional asphaltic compositions notably regarding permanent deformation. On the other hand, besides the usual pathologies, the frequent increase in the volume of traffic and loads has generated the appearance of new pathologies, not considered in the traditional methods of designing asphalt mixtures. These facts led to the study of the warm mixtures applied in the city of Manaus / AM, in terms of their mechanical performance, and in particular, from the perspective of triaxial compression and dynamic creep tests. In this research, the physical characterization of the composite materials of the asphaltic composite, the dosage of this mixture according to the Brazilian specifications, as well as the results obtained in the mechanical tests were evaluated. The physical characterization, the dosage and the mechanical behavior indicated: a) the asphalt binder was classified as type 50/70, meeting the specifications of the ANP. However, for the local reality, it does not present adequate, since in the range of service temperature has already reached its softening point; b) the mineral dosage indicated that the formulation studied can be used for Range B and C of DNIT; and c) the analysis of the Marshall parameters, from the point of view of the DNIT specification, showed that the researched composition can only be applied as a rolling layer; d) the results of the triaxial test indicated that the cohesion decreases drastically by the variation of the ambient temperature to the service condition; e) in the dynamic creep test, the mathematical model proved to be more adequate with respect to the traditional methodology, since the minimum deformation rate per cycle did not correspond to the transition point from the secondary stage to the tertiary stage; and f) all NF results, either by the mathematical or traditional method, indicate that the regional coatings are subject to premature pathologies of the permanent deformation type.