You probably think you have a good grasp of what makes up the roads you drive on during your daily commute. But if you're traveling around UC San Diego, one ingredient in the asphalt on Miramar Street may surprise you: plastic bags.
UC San Diego Construction Commodity Manager Gary Oshima first came across "plastic road" technology when he watched a TED Talk by Toby McCartney, CEO of the U.K.-based MacRebur. MacRebur has used its patented road-making process in the U.K. and Australia that takes plastic waste and mixes it into asphalt to replace petroleum-based bitumen as a binder.
Oshima contacted MacRebur, and in 2018, Miramar Street became the first roadway in the United States to be made of recycled plastic. Approximately 857,245 plastic bags from Scotland were used in the asphalt in this collaboration project between MacRebur, UCSD, California Commercial Asphalt, and Southland Paving.
"In the United States we've got plenty of roads, and we've got plenty of recycled plastic," Oshima said. "Importing it from the UK is not as good. We can make our own roads here with our own plastic, and I think that is really going to be much more appealing to municipalities, cities, and counties."
While Oshima doesn't think there are quite enough projects on campus to make a huge impact, a new San Diego company hopes to make plastic roads a common practice in California. Chris and Rebecca Sparks, who also aided in the UCSD project, recently started The Sparks Company. In collaboration with MacRebur, the Sparks Company will serve as the distributor for the overseas company's asphalt, which will be made using California's waste.
The only difference? The Sparks Company will require that the plastic used be classified as waste — meaning plastic that can't be recycled. That plastic is put into a granulator that turns it into small, 5mm pieces which are mixed with MacRebur's activator that binds it into the asphalt.
"We're only using plastics that are waste products, waste plastics rather, that go into the landfills, that go to the incineration sites, that go into our environment," said CEO Chris Sparks. "Those items are usually single-use plastic bags."
While there are no official projects in the works just yet, Sparks says he's received a lot of interest from different municipalities as well as private companies such as luxury hotels. Rebecca Sparks said that while they're excited to see their new company grow, they really only have one goal in mind.
"Our world is not sustainable with the current practices that we have going on right now as a species," Rebecca said. "Our goal is to make sure that our children have somewhere to live in the next 50 years."
For more information and MacRebur and The Sparks Company, visit macrebur.com.