Ellie Fini, associate professor, Del E. Webb School of Construction in the Ira A. Fulton Schools of Engineering, is corresponding author on Algae Asphalt to Enhance Pavement Sustainability and Performance at Subzero Temperatures, a new publication in ACS Sustainable Chemistry & Engineering.
Says Fini: A key innovation of our work is introducing polarizability as a molecular-level parameter to predict the compatibility of various bio-oils with asphalt to ensure performance! A step toward chemistry-driven design of next-generation sustainable materials. This research highlights a tangible path toward low-carbon, high-performance, and resilient infrastructure, where algae is not just a green organism, but a green solution
A brief summary follows:
This paper evaluates the potential of algae-derived biobinders as sustainable alternatives for pavement construction. It specifically examines the physicochemical and rheological properties of biomodified binders and their potential to offset carbon emissions when used as partial replacements for conventional petroleum-based asphalt binders. Biosequestration of CO2 using microalgal cell factories is a promising way of recycling CO2 into biomass via photosynthesis. Our study demonstrates that incorporating algae-derived binders into asphalt can significantly reduce carbon emissions. Each 1% increase in algae-based biobinder leads to an approximate 4.5% decrease in net carbon emissions. This indicates that a blend containing about 22% biobinder has the potential to achieve carbon neutrality. Blends with higher proportions may even result in net-negative emissions, highlighting a promising strategy for environmentally responsible road construction. In terms of performance, the study shows that certain algae-derived biobinders significantly enhance the cracking resistance of asphalt, particularly under subzero temperatures, by improving its stress-relief capacity. A key contribution of this work is the introduction of polarizability as a novel molecular-level parameter for assessing the compatibility of algae-derived bio-oils with asphalt. By capturing the electronic responsiveness of bio-oil molecules, polarizability serves as a predictive indicator of their interaction potential with asphalt components, providing a new dimension for evaluating the binder performance at the molecular scale. Among the tested materials, the biobinder derived from Haematococcus pluvialis demonstrated particularly strong improvements in resistance to permanent deformation under repeated loading conditions analogous to traffic-induced stress, as well as enhanced resistance to moisture-induced damage. These findings advance the chemistry-driven design of biomass-based binders and highlight a promising pathway toward the development of low-carbon, high-performance, and sustainable infrastructure materials.
