Performance improvements of asphalt mixtures by dry addition of polymeric additives

This paper shows the results of an experimental study concerning the development and optimization of asphalt mixtures for binder and base courses, improved with specifically engineered additives. The focus was on the mechanical improvements of the mixtures as achievable via dry modification with polymeric additives by making use of aggregate and bitumen of average quality, as locally available, in order to limit the consumption of virgin materials. The results allowed interesting conclusions to be drawn about the use of polymeric additives for these mixtures. In particular, the modified mixtures proved to have better performance in terms of both permanent deformation resistance and stiffness modulus. Moreover, it is possible to use lower binder contents, thus proving the economic feasibility of this modification, when considering the advantage of consuming mixtures with components of average quality for production of highly performing mixtures.