Estudo das propriedades físicas e químicas do ligante asfáltico CAP 50/70 modificado por adição de PET triturado.

Abstract

Asphaltic binder is a complex material, both from the point of view of chemical composition and rheological properties. It has a viscous behavior, characterized by the decrease of stiffness for long periods of application of load, and thermal susceptibility characterized by the alteration of properties (viscosity, stiffness, consistency) as a function of temperature. The modification of asphalt binders is a practice that aims to increase the resistance to permanent deformation, cracks caused by fatigue or thermal variations, as well as, consequently, improve the conditions of safety and comfort of the highways and reduce costs with maintenance. Thus, this study aims to study the physical and chemical properties of modified asphalt binder CAP 50/70 by addition of PET. The addition contents of 1%, 2% and 3% of PET were used for the physical characterization of the viscosity, softening point, elastic recovery and binder penetration before and after shortterm aging RTFO and, for chemical characterization, the FTIR. The addition of PET to the CAP 50/70 proved to be a good solution for the destination of this waste, proving to be beneficial in several physical aspects. The polymer added increased stiffness, when compared to the pure CAP, with a 3% PET, a softening point increase of 15%, proving its thermoplastic properties and can be applied in heavier services and at higher usage temperatures, however, would require a greater energy expenditure. When compared to the CAP 55 / 75E, this scenario is opposite, which is more rigid than the mixture of PET to the binder. In this comparison, it was also observed that the greater separation of phases caused by the mixing of the PET to the binder resulted in a greater loss of mass and decrease of its elastic recovery. Finally, from the chemical characterization were found CH2, CH3 (aliphatic) and C = O (carbonyl) groups, in addition to having been proved the antioxidant effect of the addition of PET to the binder.