Recycling asphalt using waste bio-oil: A review of the production processes, properties and future perspectives

• Published in: Process safety and environmental protection 2021-03, Vol.147, p.1135-1159
• Main Authors: Zahoor, Muhammad, Nizamuddin, Sabzoi, Madapusi, Srinivasan, Giustozzi, Filippo
• Format: Article
• Language: English
• Subjects: Asphalt; Asphalt mixes; Asphalt pavements; Binders; Binders (materials); Bio-asphalt; Bio-oils; Biomass; Bitumens; Chemical properties; Economic development; End of life; Landfills; Low temperature; Molecular weight; Organic based binder; Organic binders; Physical properties; Reclaimed asphalt pavement (RAP); Recycling; Rehabilitation; Rejuvenator; Resurfacing; Reviews; Rheological properties; Roads; Roads & highways; Surfacing; Thermal stability; Viscoelasticity; Waste disposal sites
• ISSN: 0957-5820; 1744-3598
• DOI: 10.1016/j.psep.2021.01.032

[Display omitted] Roads play a crucial role in the economic development of nations; reconstruction, resurfacing, or rehabilitation of the current roads result in the milling of approximately 120 million tons of asphalt pavement every year. Due to the significant volume of resources involved, road agencies constantly trade-off among economic, performance and environmental challenges to maintain and build road assets. To address these challenges – such as reducing the dependency on non-renewable petroleum-based products and minimising waste and landfills – recycling of end of life road material through various organic binders has been evaluated. Bio-oil, obtained through recycling of different sources, contains lower molecular weight components that resemble fractions of the virgin asphalt binder used to make roads. This review article focuses on the recycling of bio-oil and its utilization in asphalt binders – as an alternative, extender, modifier and rejuvenator – and asphalt mixes. This review paper provides information on the production methodology used to produce bio-oil from various types of biomass, along with upgradation techniques adopted to upgrade the bio-oil before its addition into bitumen. The chemical and physical properties of bio-oils vary for each type of biomass. The production methodology to produce bio-binder from bio-oil is also specified. Simultaneously, the effect of bio-oil on the mechanical, rheological and chemical properties are compared with those of conventional bitumen. It is concluded that the performance of bio-binder varies with the type of bio-oil used for the modification, generally improving the intermediate and low-temperature viscoelastic behaviour but reducing the high-temperature performance. This review article provides a sketch of favourable and harmful aspects associated with the utilization of bio-oil to form bio-binders.