Caracterização do comportamento reológico de ligantes asfálticos modificados por montmorilonita não organofilizada.

Abstract

Asphalt pavements are those where the coating is composed of a mixture consisting basically of aggregates and asphalt binder. The degradation of the pavement starts as soon as it goes into service and the vehicles begin to circulate on the surface. This degradation is still affected by the action of atmospheric agents (rain, wind, solar radiation), which can induce deterioration in the pavement. The study of its physical and rheological properties has increasingly intrigued researchers in the field, especially when these binders are modified by polymers such as styrene butadiene-styrene (SBS) copolymer. They exhibit greater resistance to sinking and thermal deformation, reduce fatigue damage, and further decrease thermal susceptibility. The main advantage of using montmorillonite (MMT) in paving is to build pavements that are more resistant to deformation and fatigue cracking, increasing its rigidity and resistance to aging. This research has as main objective to study the rheological properties of the CAP 50/70 modified by montmorillonite. For this purpose, penetration, softening point and rotational viscosity tests were performed, as well as tests using the Dynamic Shear Rheometer, such as PG, MSCR and LAS, in order to obtain a more representative analysis of the rheological behavior of the CAP 50 / 70 modified with montmorillonite before and after short-term aging and to compare it with both the CAP 50/70 and the SBS modified binder. The results indicated that MMT-modified binders are more resistant to oxidative aging, more rigid, have lower initial integrity in the presence of damage accumulation and are less resistant to deformation when compared to pure CAP 50/70. Compared to polymer modified asphalt (AMP) 55/75 SBS, the binders incorporated with MMT are less resistant to permanent deformation, less susceptible to voltage variation, less resistant to accumulated damage, less sensitive to increased strain amplitude and aging oxidative.