Developing recycled asphalt binder using ecofriendly bio additives

Paving recycling technique gaining high attention for environmental and economic considerations. Bio oils among which Waste Engine Oil (WEO) can been used as aged asphalt rejuvenators. WEO has a bad effect on high temperature rutting performance in spite of it is a good flow improver at low temperature. In this research, Starch (ST) and Bone Glue (BG) as natural modifiers were used to increase the high temperature performance of rejuvenated aged asphalt using WEO previously prepared. ST and BG were chosen as inexpensive, available, and ecofriendly modifiers to overcome artificial modifiers disadvantages as storage stability, high cost, air pollution and incompatibility. WEO was used in rejuvenating asphalt mix consisted of 100% Reclaimed Asphalt Pavement (RAP) in a previous work. 0.75% ST and 0.5% BG (%wt. of binder) were found to be optimum contents for modifying rejuvenated RAP using Marshall test. All binders were characterized for physical, chemical, rutting factor at high temperature using Dynamic Shear Rheometer, and molecular structure. Modified RAP mixes were evaluated for mechanical tests and compared to new mix containing virgin asphalt. The results revealed that comparing to new mix, modified RAP mixes have higher rut, raveling, fatigue, and moisture resistances in percentages of 62,24,10&34% respectively. Also, the failure temperature of modified asphalt increased from 52 degrees C for rejuvenated aged asphalt using WEO to 70 degrees C as that recorded for virgin binder. ST and BG were bind physically with the rejuvenated aged binder. Finally, natural modifiers can be used practically with bio-oil in paving recycling.