Estudo das propriedades reológicas do CAP 50/70 modificado por politereftalato de etileno.

Abstract

The growth in the amount of vehicles on road, associated with the increase in the weight and on the number of axles of the commercial vehicles, has caused cracks due to fatigue and permanent deformation in wheel tracks. The first relates to repeated traffic loads and also to the elasticity of the mixture and the last develop gradually with an increase on the load at each axle. Therefore, in order for the asphalt binder to perform satisfactorily on the pavement, it must have different properties with respect to the behavior of the other asphalt materials. This should present greater cohesion and adhesion to the aggregates, great resistance to aging, adequate thermal susceptibility to the pavement temperature range, high fatigue resistance and thermal deformation. In this sense, this study aims to study the rheological properties of the modified asphaltic binder by PET. Rheological tests, MSR (Multiple Stress Creep Recovery) and PG for the binder with addition of 2% and 3% of PET before and after short-term aging-RTFO. From the analysis of the results it was verified when carrying out the procedure of RTFO, that for the CAP modified with 2% and 3% of PET there was a lower susceptibility to aging in relation to the pure CAP, since the loss of mass of both was lower compared to loss of pure CAP. As for the degree of performance both remained at 64 ° C for both the virgin and aged modified binder, thus demonstrating the antioxidant effect of PET, while the pure CAP despite having the same 64 ° C virgin performance, when passing by the aging process has its degree of performance reduced to 58 ° C. Still in the PG test when analyzing the obtained parameters an improvement in the properties of the binder, the increase in the resistance to the deformation and the fatigue was observed. In the MSCR test the modified CAP with a 2% content is not indicated for paving and with a 3% content it decreases the level of traffic in relation to the pure CAP of heavy to standard. In addition, both levels presented low elasticity and, consequently, very low recovery percentages, not very different from pure CAP. Finally, it was realized that PET can be used as a modifying agent of CAP and that it is capable of promoting gains in the mechanical properties of the asphalt binder.