Enhancing the performance of wood-based bio-asphalt: strategies and innovations.

This paper offers a survey of progress in utilizing bio-oil from wood and forestry waste for creating eco-friendly asphalt pavements, with a focus on sustainability and future research directions. The substantial yearly production of wood and forestry waste often ends up in landfills. However, using pyrolysis to convert this waste into bio-oil presents an alternative to petroleum-based asphalt binders. Bio-oil shares characteristics with traditional binders used in asphalt, resulting in three main applications: bio-asphalt, bio-rejuvenator, and polyurethane (PU)-modified bio-asphalt. Bio-asphalts, though similar to traditional binders, display vulnerability to aging, experiencing mass loss and volatile component evaporation when aged. Bio-oil incorporation affects high- and low-temperature performance grades adversely, limiting its usage due to susceptibility to aging and impact on high-temperature performance. To tackle these issues, additives like rejuvenators, polymers, nanomaterials, and crumb rubber have been introduced to enhance aging resistance and overall performance of bio-asphalt. Wood-based bio-oil, due to its low viscosity and compatibility with petroleum-based binders, is suitable for rejuvenating aged asphalt. The optimal wood-based bio-rejuvenator percentage is 5–20%, with recommended mixing conditions of 130–145 °C, 1000–3000 rpm, and 10–30 min. Innovatively, polyurethane (PU) modification involves incorporating isocyanate into bio-asphalt to create PU-modified bio-asphalt, yielding improved strength, increased high-temperature viscosity, enhanced elastic recovery, and resistance to low-temperature cracking. [ABSTRACT FROM AUTHOR]