Implementação do ensaio stress sweep rutting e do shift model para a previsão da deformação permanente e misturas asfálticas brasileiras

Abstract

The characterization of the resistance to permanent deformation is essential for the adequate selection of asphalt mixtures to be used in the construction of pavements. In Brazil, the Flow Number has been adopted in the dosage phase to differentiate mixtures. This test fulfills its role well for the conditions for which it was designed. However, the incremental accumulation resulting from the traffic application must be considered, in addition to taking into account variations in the magnitude of loads and the temperature at which the material is exposed. Therefore, this research analyzes the resistance to the accumulation of permanent deformation of asphalt mixtures from the Triaxial Stress Sweep Rutting (SSR) test, from the so-called Shift Model and from structural analyzes of the pavement in the FlexPAVETM program. Three asphalt mixtures used in the field were analyzed and their performance in the field was compared with laboratory results, which allowed the development of a preliminary transfer equation. Another 11 mixtures were analyzed in order to understand the effect of aggregates and asphalt binders on the permanent deformation of mixtures. The results showed that the use of polymer-modified binders can significantly improve the performance of mixtures in the field. It was not possible to identify the most relevant parameter for the selection of aggregates that generate higher resistant asphalt mixtures in terms of permanent deformation. Finally, it was observed that the combination of the SSR, the Shift Model and structural simulations in FlexPAVE TM are an efficient strategy for the characterization of the incremental permanent deformation and for the evaluation of the structural damage observed in the field.