In the quest for sustainable and circular infrastructure, researchers have made a significant stride in the realm of asphalt recycling. A recent study published in the journal *Materials & Design* (translated from Chinese as “Materials and Design”) sheds light on the molecular mechanics behind recycling aged bitumen using a bio-based rejuvenator derived from tall oil. This research, led by Liang He from the School of Civil Engineering at Chongqing Jiaotong University, could have profound implications for the energy and construction sectors, offering a greener alternative to traditional methods.
The study compares the effectiveness of a bio-based rejuvenator, tall oil (T-type), with a conventional aromatic oil rejuvenator (A-type). The findings reveal that T-type molecules possess larger dipole moments and more heterogeneous surface electrostatic potential distributions, leading to stronger molecular polarity. This enhanced polarity allows T-type rejuvenators to interact more effectively with asphaltene aggregations, disrupting π–π stacking and increasing stacking distances. “The T-type rejuvenator demonstrates superior regeneration effectiveness and surface repair of aged bitumen compared with A-type,” explains Liang He, the lead author of the study.
The research employed a combination of rheological tests, atomic force microscopy, and Fourier-transform infrared spectroscopy to evaluate the high- and low-temperature performance of regenerated binders and examine microstructural morphology and functional groups. To bridge macroscopic and microscopic observations, the team conducted molecular dynamics (MD) simulations and quantum chemical analyses. The results provide mechanistic insight and methodological guidance for the reverse design of bio-based rejuvenators, supporting their selection in sustainable asphalt recycling.
The commercial impacts of this research are substantial. As the demand for sustainable and circular infrastructure grows, the construction and energy sectors are increasingly seeking eco-friendly alternatives to traditional materials. The use of bio-based rejuvenators like tall oil could reduce the environmental footprint of asphalt recycling, making it a more attractive option for companies looking to meet sustainability goals. “This research not only advances our understanding of the molecular interactions involved in asphalt recycling but also paves the way for the development of more effective and sustainable rejuvenators,” says Liang He.
The study’s findings could shape future developments in the field by encouraging further research into bio-based rejuvenators and their applications. As the construction industry continues to evolve, the adoption of sustainable practices and materials will be crucial in reducing environmental impact and promoting circular economy principles. This research represents a significant step forward in that direction, offering a promising solution for the recycling of aged bitumen and the advancement of green, circular, and sustainable transport infrastructure.