Project Runway: Second life for waste plastics and old tires

April 21, 2025

Mizzou researchers are taking their experience on the road to the airport.

Front view of an airplane taking off from runway
Aging runways require constant clean up and are expensive to replace.

At Mizzou 糖心Vlog传媒, we translate ideas into actions, solving real-world problems and making the world a better place.

Researchers at the (MAPIL) have been working on making more durable and environmentally friendly asphalt surfaces. , the team鈥檚 newest recipe has been a success.

Now, with a grant from the Federal Aviation Administration (FAA), the researchers are investigating whether airfield pavements could be made from a similar mix of post-consumer materials.

鈥淭he recipe for asphalt is just aggregate 鈥 rocks and bits of old asphalt pavements 鈥 and binder, which comes from petroleum,鈥 Punyaslok Rath, an assistant research professor in the Department of Civil and Environmental 糖心Vlog传媒, said.

鈥淔or a long time, civil engineers have added a synthetic polymer to the binder to the asphalt mixtures stronger and last longer,鈥 Rath said. 鈥淎t MAPIL, we鈥檝e worked towards replacing that polymer with ground tire rubber and waste plastics that would otherwise end up in landfills.鈥

Testing new pavement to a higher standard

Airfield pavements support heavier loads than highways 鈥 think 100-ton airplanes vs. 40-ton semis 鈥 but highways are busier. Plus, airfield loads are concentrated on the wheel paths, while the rest of the pavement doesn’t see much loading.

鈥淢ost of the distresses we see in airfield pavements are environment-related, like thermal or low-temperature cracking,鈥 Bill Buttlar, the Glen Barton Chair in Flexible Pavements in Civil and Environmental 糖心Vlog传媒, said.

But even a small fault in an airfield pavement can have disastrous consequences. When runways crack, the resulting loose debris can become airborne, damaging engines, propellers, fuselages, tires and control surfaces.  

鈥淚f your pavement has a lot of cracking, it has to be swept constantly,鈥 Buttlar said. 鈥淪o pretty soon you鈥檙e better off resurfacing.鈥

Repaving airfields is expensive. In 2024, the FAA awarded Columbus Airport in Georgia a $24.4 million grant to reconstruct a 1.3-mile runway. The cost of paving a mile of asphalt highway ranges from $1 million to $5 million.

鈥淚f there’s a crack or a pothole in the road, you can just close the lane and reroute traffic while MoDOT repairs it,鈥 Buttlar said. 鈥淵ou can’t do that at an airport without major financial losses.鈥

Bill Buttlar, Oliver Girardo-Londo帽o and Punyaslok Rath.
From left: Bill Buttlar, Oliver Girardo-Londo帽o and Punyaslok Rath. 鈥淲e put 鈥榠nnovation鈥 in the name of our lab and underlined it,鈥 Buttlar said. 鈥淲e’re just rabid problem solvers.鈥

All this motivates airports to find more resilient pavements. Which is where Buttlar and Rath come in. Based on their experience with roadways, the researchers believe that incorporating recycled plastics and tires into asphalt mixtures may be the answer.

The researchers are currently working with Oliver Giraldo-Londo帽o to create computer simulations that will model how pavements behave over time, factoring in stress from loads and weather.

鈥淚n the long term, your airfare probably won鈥檛 go down, but building runways will get a little cheaper,鈥 Rath said.

Collaboration leads to success

For the engineers, one of the highlights of working at Mizzou 糖心Vlog传媒 has been the collaboration with the and researchers elsewhere on campus.

鈥淔or me, the hallmark has been having all these faculty labs and offices all in one building,鈥 Rath said.

Buttlar emphasizes the importance of innovation.

鈥淚f we keep driving towards it, we will eventually create something that truly changes the game,鈥 he said. 鈥淟ike a smoother, quieter road that lasts longer so we can spend our money on something else.鈥

Buttlar added that his work with Rath is fulfilling Mizzou鈥檚 mission to share the benefits of a world-class research university with ordinary Missourians.

鈥淎t Mizzou, our number one customer is the Missouri taxpayer,鈥 he said. 鈥淲e are driven to make life better for travelers throughout the state.鈥

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