The hot mix asphalt (HMA) industry is embarking on a program to substantially reduce mix production temperatures. Reduced mix production and paving temperatures would decrease the energy required to make HMA, reduce emissions and odours from plants, and improve the working conditions at the plant and paving site. Warm mix asphalt (WMA) refers to technologies that allow substantially reduced HMA mix production temperatures. This paper presents the Superpave binder test results of warm asphalt binders containing crumb rubber modifier (CRM). Rubberized binders were produced at 10 per cent by binder weight using three binder sources, and warm asphalt binders with CRM were produced using two of the available processes and artificially short-term and long-term aged through rolling thin film oven (RTFO) and pressure aging vessel (PA methods. Tests were conducted on the binders using the rotational viscometer, the dynamic shear rheometer, and the bending beam rheometer. The results indicated that the viscosity properties of rubberized binders can be changed significantly through the use of warm asphalt additives. Also, the addition of the additives was expected to improve rutting resistance of the rubberized binders. However, the rubberized binders containing the additives were expected to be less resistant to cracking at intermediate and low temperatures. (a) For the covering entry of this conference, please see ITRD abstract no. E217099.
Abstract