Estimativa de propriedades viscoelásticas lineares de misturas asfálticas completas a partir da caracterização da matriz de agregados finos

Abstract

If bituminous mixes are subjected to small strains and low number of loading cycles, its behavior can be assumed to be in the linear viscoelastic domain. In such case the binder has an important influence in the stiffness and phase angle properties, and also in the timetemperature dependence. A new method called SHStS was developed to predict the linear viscoelastic behavior of asphalt mixes from the linear viscoelastic characterization of the associated binder, in order to save time and material in laboratory testing. This method can be translated in a graphical transformation when analyzing the binder curve in Cole-Cole space, in which a homothetic factor and two shift factors are applied. Additionally, a shift factor in time is applied, as evidenced in frequency dependent curves, such as the dynamic modulus master curve. The SHStS transformation has been acceptable to predict the linear viscoelastic behavior of mixtures for different compositions. However, it has been noticed that polymer modified binders do not comply with its associated mixes experimental data. In such situations, it is believed that a test material with aggregates incorporation, such as FAM, can provide better predictions. Generally, the application of SHStS requires the use of a rheological model, to obtain the necessary parameters to the transformation. In this case, the 2S2P1D model was used; whose efficacy to represent the linear viscoelastic behavior of binders, mastics and mixes has been attested in different studies. Therefore, one of the aims of this study was to evaluate the applicability of the 2S2P1D model in FAMs, which has been acceptable especially to the modeling of dynamic modulus, in a wide spectrum of frequency and temperature. The SHStS methodology, in turn, has been consistent with the hypothesis that the binder is the origin of the time-temperature dependency of asphalt mixtures, and it has shown great potential to application in laboratory.