Jean Walter
Technical Development Department Director Nynas (UK)

Pierre Attané
Professor Laboratory of Rheology.
University Joseph Fourier (UJF, Grenoble, France)

Ahmad Kalaaji
Post-Doc. University Joseph Fourier (UJF, Grenoble, France)

Ian Lancaster
Nynas Chemical Development Department (United Kingdom)

ABSTRACT
This article summarizes the work carried out by Nynas and the Joseph Fourier University in Grenoble on the interaction between the new binder made in recycled and the hard bitumen content in the aged mixture. Following the behavior of two layers in tests conducted with a dynamic shear rheometer ( "Dynamic Shear Rheometer" DSR), the interaction of hard / soft (or rejuvenating) bitumen bitumen was studied. This theoretical approach was completed by a study of milling.

All clearly indicates that there interaction phenomena at room temperature between the new binder and the aged. Are, however, slow phenomena that may develop over several months or even several years. It is possible, however, modify the behavior of milling stage compaction provided to have a contact time between the rejuvenating and milling at least 7 days. Finally, it appears that a milling presents a remarkable difference in behavior to compaction according to the ambient temperature (5 to 40ºC).

In conclusion, finally, some suggestions for a practical application of these results are presented.

KEYWORDS:
Recycling, Cold recycling, Milling, Asphalt emulsion, Foam bitumen, bituminous binder, aged bitumen, SCORE Project.