BATON ROUGE, LA (WAFB) - The busy roads of Baton Rouge are constantly taking a pounding.
“Every day we drive on the road. We use it and sometimes we face potholes or cracks or uneven pavement. We probably even sometimes complain," says Professor Guogiang Li with the LSU College of Engineering. “But we never stop and ask: what happened, why did it behave this way?”
Professor Li says road conditions can change based on the traffic load, water in the foundation or quick change in temperature. That can create cracks and potholes. The hard part, which has been 9 years in the making, is figuring out how to fill holes with a more permanent solution.
“If you avoid the damage, the water from the top will not get into the bottom. So, in such a way the pavement will not lose the support from the base. We may extend the service life of the pavement,” Li says.
Professor Li and his team have created a two-way shape memory polymer that deals with one factor associated with road damage, thermal stress. In the winter, pavement shrinks, and in the summer, it expands. The material used to fix potholes should work opposite the pavement, he says.
“The two-way shape memory polymer actually behaves the way we’re expecting,” Li says. “When you cool it down, it starts to expand. Once you heat it up it starts to shrink.”
Nationwide, he says, city governments normally use rubber modified asphalt or something similar to fix potholes and over the years, they break. This invention, he says, has good connectivity, fills in the cracks where it’s needed, and lasts longer.
“We are trying to make a product which is competitive in terms of the service life. Instead of one year let’s say five or ten years, without changes. The second is the initial cost," Li said.
Professor Li says the movement and elasticity in the material are necessary. The product should cater to the load on the roads,
“This twisting and bending...we want to see that this material can hold different traffic loads and temperature changes," he said.
Although this product is still in the lab testing phase, years ago, they tested a similar material on LSU’s campus. The professor says so far so good.
The next step is entering the full-scale testing phase. First, the product will be tested at the Texas Transportation Institute for validation. Once approved, the material will go to full-scale testing in Louisiana Transportation Research Center where they will have access to the acceleration loading facility for three months, which is equivalent to the real-world use of 20 years.
Professor Li says they’re attempting to see how the sealant performs in hot and humid conditions with the heavy traffic loads.
The final testing will take place in Minnesota to see how materials perform in the cold region.
If the material passes all tests, the next stage is commercialization.