Laboratory eva‎luation and variance analysis of the effect of polymer rejuvenators on the behavior of HMA asphalt mixtures containing high RAP in the short and long term.

2/13/2024 12:00:00 AM

The high price of bitumen has resulting in the cost of producing of the asphalt mixtures to increase. On the other side , the huge volume of Reclaimed Asphalt Pavement (RAP ) production has given researchers the motivation to investment the amount of (RAP) in asphalt mixtures. However, the bitumen in the (RAP) becomes stiff and fragile due to exposure to environmental conditions, and the using the (RAP) increases the hardness of the esphalt mixture and reduces the cracking resistance. Therefore, researchers have recommended to use the rejuvenators to compensate the hardness of(RAP) bitumen . Many researchers have shown that using the rejuvenator and polymer bitumen simultaneity can improve the performance of cracking and fatigue and rutting resistance of recycled asphalt mixtures. However, rejuvenators modified with polymer has not been worked on to a large extent until now and the effect of polymer rejuvenators on the behavior of recycled asphalt mixture has been less investigated and there are many uncertainties in this regard. Therefore, in this research, the strength of recycled asphalt mixtures containing 0, 25, 50, and 75% (RAP) with polymer rejuvenators such as nanopoly, Tis polymer rejuvenator, and waste cooking oil containing crumb rubber have been studied Also as well as the results that obtained compared with the results of preva‎lent non-polymer rejuvenator vacuum bottom rejuvenator. Asphalt specimen containing different percentages of regenerated (RAP) by different rejuvenators were subjected to dynamic creep, moisture sensitivity semi circular bending (SCB) tests. The results indicated that Tiss and Nanopoly polymer rejuvenators increases the resistance of rutting and the flow number of the dynamic creep test increases by 3 to 6 times by adding the polymer rejuvenator. Also, waste cooking oil containing crumb rubber in the low and medium RAP percentages have a favorable effect on thE creep performance of recycled asphalt mixtures. The fracture energy and critical value of integral J of recycled asphalt mixtures containing vacuum bottom (VB) is about 2 to 4 times higher than the mixtures that containing polymer rejuvenators. However, polymer rejuvenators, in spite of having low resistance to crack initiation, had better resistance to cracks growthing than vacuum bottom rejuvenator. The results of failure SCB of aged specimen showed that the lowest and highest resistance to aging is related to waste cooking oil containing crumb rubber and Tiss rejuvenator.

تراشه آسفالت بازيافتي , جوانساز , روغن خوراكي , پودر لاستيك , جوانساز پليمري

Recycled Asphalt , Rejuvenator , Waste Cooling Oil , Crumb RUbber , Polymer Rejuvenator

Mohanad Albayati

Dr. Hassan Ziyari