Fatigue Tests in Modified Binders and GapGraded Asphalt Mixtures with Reacted and Activated Rubber – RAR

Description

Letícia Nunes,  Márcio Muniz de Farias, Luiz Guilherme Rodrigues de Mello

ABSTRACT. Fatigue resistance is the ability to withstand repeated loads without cracking and is associated with the stiffness of the material. Cracking can be reduced using modified asphalt binder with the incorporation of ground scrap tire rubber to produce rubberized asphalt via the wet process. This process results in a highly viscous material with enhanced engineering properties, but requires a specific equipment that is typically installed at the job site, or close to the supplying asphalt plant. Furthermore the manufacture requires high temperature and long mixing time. In this context, new materials, also called 4th generation rubberized asphalt, such as Reacted and Activated Rubber – RAR were developed with the purpose to simplify the manufacturing process (as in the asphalt mixtures obtained by the dry process) and to enhance the performance of the asphalt mixture (as in the asphalt mixtures obtained by the wet process). In order to evaluate the influence of this material on the fatigue performance of an asphalt mixture, a conventional binder (AC 50/70) was mixed with RAR in quantities of 25% and 30% by mass, and the modified binder was used to produce a gap graded hot asphalt mixture. The rheological behavior and the fatigue resistance of the neat binder (AC 50/70), modified binders.