Análise reológica do ligante asfáltico modificado com cal hidratada.

Abstract

In the last decades, the significant increase of the traffic in the paved roads has accelerated the deterioration of the asphaltic coverings. Because of this, the use of additives has been studied to modify the properties of the asphalt binder, in order to improve the service performance mainly related to permanent deformations and fatigue life. This work proposes to evaluate changes in the physical and rheological CAP50/70 properties modified with fractionated hydrated lime particles, from the use of a ball mill. For that purpose, conventional tests were performed (penetration, rotational viscosity and softening point) and in the dynamic shear rheometer (DSR). The mixtures were performed with the addition of lime fractions at 3%, 5 % and 7% by mass of the pure binder. The results in the empirical tests, both the pure binder and the modified binder have met the recommended limits by the ANP and DNIT. The modified samples showed a lower loss of mass in the short term aging, showing an antioxidante alternative. In addition, it was found that the modified binders increase of the G* (stiffness parameter) and, consequently, of the maximum of Performance Grade (PG), allowing the use of binders studied at higher temperatures, increased rigidity, enabling the use of binders studied at higher temperatures. The modified binder with 5% content of hydrated lime presented better results in the permanent deformation tests. Finally, it was possible to established that the fractional particles of hydrated lime addition to the CAP 50/70 is a feasible and effective technique that meets the requirements DNIT for use in paving.