Characterization of recycled crumb rubber modified binders containing wax warm additives

This paper addresses the laboratory experiment of performance properties of recycled CRM binders containing artificially aged CRM binders with wax additives. The warm CRM binders were produced using two wax additives (LEADCAP and Sasobit) and then short-term and long-term aged using the rolling thin film oven (RTFO) and pressure aging vessel (PAV) procedures. The recycled CRM binders were aged through the RTFO and PAV procedures. A set of Superpave binder tests were carried out on the binders through the rotational viscometer, the dynamic shear rheometer (DSR), and the bending beam rheometer (BBR). In general, the results of this study indicated that (1) the addition of long-term aged (LTA) CRM binder can significantly increase the viscosity of the recycled CRM binders as expected, (2) the wax additives in recycled CRM binders were still effective to improve the viscosity and rutting properties even after experiencing the aging process, (3) the CRM binders containing wax additives showed the higher rutting resistance compared to the control CRM binders, (4) the recycled CRM binder containing wax additives was found to have less resistance to fatigue and low temperature cracking, (5) wax warm additives into the recycled CRM binders seemed to have a significant role for cracking properties, based upon their substantial amount.