Balancing the Aromatic and Ketone Content of Bio-oils as Rejuvenators to Enhance Their Efficacy in Restoring Properties of Aged Bitumen
Chong Li, Amirul Islam Rajib, Manobendro Sarker, Ronghou Liu, Elham H. Fini, Junmeng Cai
Abstract
The potential of the bio-oil from the co-pyrolysis of poplar wood and waste tire rubber to revitalize severely aged bitumen was examined by shifting the balance of aromatics and ketones in the bio-oil. Laboratory experiments were performed to compare the revitalization efficiency of bio-oils from the pyrolysis of poplar wood and co-pyrolysis of wood and waste tire rubber. Furthermore, the chemical compositions of the bio-oils from both processes were studied using gas chromatography–mass spectrometry to distinguish how each bio-oil revitalized severely aged bitumen. The results showed that the wood pyrolysis bio-oil had high phenol and ketone relative contents but very low aromatic and alkane relative contents. In contrast, significant relative amounts (19.18%) of aromatics and alkanes and a lower ketone relative content (0.95%) were found in the co-pyrolysis bio-oil. The rheological characterization of aged bitumen rejuvenated with both bio-oils showed that the co-pyrolysis bio-oil was much more effective than the wood pyrolysis bio-oil, which was evidenced by a higher crossover modulus and frequency as well as lower shear thinning in the aged bitumen rejuvenated by the co-pyrolysis bio-oil. These results prove that the co-pyrolysis bio-oil is a potential asphalt rejuvenator.