REPRESENTATIVE IMAGE
Asphalt has been laid on American roads since 1870, yet scientists still do not fully understand how its chemistry changes as it ages.
“It’s like an MRI for early cancer detection, but for asphalt failure,” Woelk said. Woelk said the team’s results could also help set standards for asphalt rejuvenation materials, the oils applied to older pavement to restore some of its flexibility. Potholes rarely appear out of nowhere. Long before a road cracks open, the asphalt has already started to age, turning stiff and brittle after years of exposure to oxygen, sunlight and rain. Researchers at the Missouri University of Science and Technology (Missouri S&T) in the US are now working on a way to read those early warning signs, so road agencies can fix a stretch before it fails. The team, led by Dr Klaus Woelk, professor of chemistry at the university, is studying asphalt samples with a spectrometer that uses nuclear magnetic resonance (NMR), the same principle behind hospital MRI scans. The machine stimulates the material and measures how its physical properties have shifted with age. The goal is a tool that municipalities could use to pinpoint which parts of a road are breaking down. That gap is why most repairs happen only after the damage is visible. Such standards, he added, would be a strong selling point for companies that mass-produce these oils and work with transportation departments across the US.
Because local climate has a huge impact on how asphalt holds up, catherine Skaggs, a student on Woelk’s team, said roads in Minnesota need very different care from roads in Louisiana,. Weather makes the job harder. Heat is a clear example. In states like Texas, extreme temperatures soften asphalt, making it easier for heavy vehicles to crack and deform the surface. Texas has experimented with plastic roads to deal with this, while other projects have tested self-healing concrete that could keep potholes from forming. Still, asphalt is unlikely to be replaced soon. It remains the most economical material for building roads, and repairing it is cheap and simple. Its biggest weakness is how quickly potholes appear. If the Missouri S&T approach makes it from the lab to the road, cities could fix roads on their own schedule, instead of after a tyre finds the damage first. You use AI every day. Now get your AI Quotient. Take the AIQ test.