Old tires added to the asphalt mix enable roads to last twice as long.
Prolonged sun exposure is one of the primary contributors to asphalt cracking. That’s because the heat from the sun dries up the road, making it brittle. However, the good news is that a team of scientists has found that adding rubber from old tires to asphalt can help roads last twice as long before developing cracks.
The team of researchers at Australia’s RMIT University has come up with an eco-friendly solution that can protect roads from the harsh rays of the sun. The method involves adding crumb rubber from scrap tires to the road recipe — addressing both the environmental impacts of road maintenance and the waste problem of discarded tires. It's a win win.
As part of the study, the team tested the protective effects of crumb rubber by adding it to the top layer of asphalt in different concentrations and to discover the ideal blend.
“We found adding between 18 percent and 22 percent of crumb rubber generates an ideal balance in terms of improving rut and fatigue resistance to traffic loads while resisting UV aging,” said study lead author Filippo Giustozzi. “This acts so effectively as a sunscreen for roads that it actually makes the surface last twice as long as regular bitumen. We knew that UV would be a factor in road degradation, but not by what degree or how to protect against it, as nobody has really been looking at this aspect.”
Carbon Negative Roads: Similar to building new roads, repairing existing ones is not an environmentally friendly endeavour. One of the main problems is bitumen, a fossil fuel-derived binder. A startup in Norway is recycling old roads using a plant-based binder instead, a process that could significantly shrink the carbon footprint of our roads. More...