Evaluation of warm mix asphalt mixtures containing reclaimed asphalt pavement and crumb rubber

This study investigates the potential use of crumb rubber and Reclaimed Asphalt Pavement (RAP) in Warm Mix Asphalt (WMA). In fact, the twofold purpose of this research is to improve the performance of asphalt pavement and mitigate the environmental impacts caused by waste tires and aged asphalt pavement. In the present paper, seven different asphalt mixtures including 30% and 60% RAP (by the weight of natural aggregate) were modified by 0, 10%, and 20% crumb rubber powder. To this end, natural aggregate was replaced by the different percentages of RAP and crumb rubber in the asphalt mixtures. Also, high percentages of organic additive, Sasobit, including 4% and 5.5% were employed to the mixtures including 30% and 60% RAP, respectively. The findings of this present investigation resulted from Marshall Stability, moisture susceptibility, fatigue cracking, and permanent deformation tests indicate that the high amount of Sasobit can not only reduce the mixing and compacting temperatures, but also provide a sophisticated asphalt mixture modified by crumb rubber, and simultaneously it can be considered as a practical method against global warming and stockpiling waste materials such as RAP and end-of-life tires. Overly, the rubberized asphalt mixtures including high RAP and high Sasobit additive provided a better behavior against moisture susceptibility, fatigue cracking and permanent deformation in comparison with the control mixture, CW.