Evaluation of the behavior of hot-recycled asphaltic mixtures with reclaimed asphalt

ABSTRACT

The objective of this study is to evaluate the technique of hot recycling in asphalt mixtures relative to the mechanical properties, for the purpose of verify the adequacy of their employment in substitution of virgin granular material for Reclaimed Asphalt Pavement (RAP) in different percentages, for the application in layers of pavement. To achieve the purpose of this study, laboratory tests were made to evaluate the mechanical properties and adhesiveness of mixtures containing 10% addition of RAP, 20% and 30%, compared to a reference mix without RAP. For stiffness evaluation were used resilient modulus tests (RM) and uniaxial dynamic modulus test. Besides these tests was performed the indirect tensile strength tests (RT) and Flow Number test (FN) for mechanical evaluation, damage tests induced moisture through the Modified Lottman test and Cantabro abrasion, for evaluation of the properties of adhesion and cohesion of the mixtures, respectively. Analyzing the results, an important economy of asphaltic binder was observed, whereas the RAP contains aged binder It´s possible to reduce the new binder content between 12.9% and 35.7% for mixtures with 10% and 30% recycled material, respectively. The experiment indicated the RAP addition affects the modulus and increases the stiffness of the mixtures; the FN test showed the resistance gain to the permanent deformation of the mixtures as well as there were no significant problems of adhesion, in other words, the losses are insignificant and do not compromise the use of this material.

Keywords
hot recycling; RAP; dynamic modulus