Algae-based asphalt resists cracks and survives deep freezes

Researchers have developed a new algae-based binder for asphalt that significantly improves road durability in freezing temperatures while reducing carbon emissions. Traditional asphalt uses bitumen, a petroleum-based binder that becomes brittle in cold weather, leading to cracks, potholes, and costly repairs. The team, led by Elham Fini, created a rubbery binder derived from oils of microscopic algae, particularly from the freshwater green microalga Haematococcus pluvialis, which demonstrated superior resistance to deformation and moisture damage under simulated traffic and freeze-thaw conditions. Laboratory tests showed that asphalt incorporating the algae-based binder exhibited up to a 70% improvement in deformation recovery compared to conventional asphalt. Environmentally, substituting just 1% of petroleum binder with algae oil could reduce net carbon emissions from asphalt by 4.5%, with a 22% substitution potentially achieving carbon neutrality. This innovation promises more sustainable, resilient roadways without significant cost increases, addressing both infrastructure longevity and environmental impact. The research was funded by the