Critical Reclaimed Asphalts Binders’ Properties from Empirical and Functional Point of View

Abstract

Due to ageing processes bituminous binders undergo significant changes in terms of viscoelastic behavior. Generally, binders become harder, stiffer, more brittle and more elastic. Such materials are then, as a part of reclaimed asphalt (RA), reused during the production of new asphalt mixtures (in an ideal case). The presence of RA, however, can in turn negatively influence the properties of the final mixture. More often than not aged bituminous binder properties are tested in terms of empirical properties, e.g. softening point or needle penetration. However, the functional properties or critical parameters are normally overlooked especially in Europe. Therefore, the article’s aim is to describe the behavior of various reclaimed binders via functional approach. The characterization of extracted binders was carried out by using dynamic shear rheometer as well as bending beam rheometer. Critical low and intermediate parameters were evaluated. The results indicated that the behavior of reclaimed binders is quite variable. Moreover, it was found out that the needle penetration test might overestimate the degree of aging which can potentially lead to excluding some materials from recycling purposes.