Estudo de diferentes mineralogias de mástiques asfálticos em relação ao fenômeno de envelhecimento

Abstract

The aging of the asphalt binder leads to a decrease in the pavement's longevity. Therefore, studying this subject is of supreme importance to improve the asphalt mixture's dosage and ensure more efficient and economically viable protection. Several research studies have demonstrated that fillers can have a positive effect in countering the aging oxidation process. Additionally, it is well-known that limes play a significant role in delaying this phenomenon. The main objective of this work is to comprehend how different mineralogies of fillers impact the aging process and which one inhibits it most effectively. Basalt, marble, dolomitic lime, and calcitic lime were employed as fillers. These materials were added to the asphalt binder in a proportion of 40% relative to the binder volume, resulting in the formation of mastics. Subsequently, the materials underwent aging using the RTFOT, PAV, and SUNTEST methods, and they were combined to create seven different levels of aging. The Dynamic Shear Rheometer (DSR) test was conducted to analyze the linear viscoelastic behavior (LVE) of both the mastics and the binder, utilizing the 2S2P1D stiffness mathematical model. The study focused on investigating how the seven parameters varied during the modeling process, particularly analyzing the stiffness curves of |G*| and ().In addition, a quantitative analysis of the variation of |G*| and () was performed to evaluate the aging effect. Furthermore, a study of the degree of physical interaction between the binder and the fillers was conducted. In the LVE behavior analyses, it was observed that the parameters of the 2S2P1D model changed according to the degree of aging of the samples. Additionally, the stiffness curves indicated that the levels PAV + SUNTEST and RTFOT + PAV + SUNTEST experienced the highest degrees of aging.Regarding the variation of |G*| and (), it was inferred that, for most aging levels, the dolomitic lime efficiently inhibited the aging of the asphalt binder. However, fillers derived from rocks showed more effective retardation of photoaging compared to lime-based fillers. Finally, the filler with the strongest interaction with the asphalt binder was the calcitic lime. Nevertheless, aging levels with PAV or in combination with it demonstrated a stronger interaction with rock-derived fillers such as marble and basalt.