Supporting Traffic with Trash: A Pollution Control Transportation Solution

From our landfills to our oceans and everywhere in between, plastic waste pollution is a huge environmental issue. Meanwhile, bridges around the United States are decaying and posing serious safety concerns to the residents across the country. To begin tackling these two seemingly unrelated issues at once, engineers have begun developing methods to put non-biodegradable thermoplastics to work for transportation infrastructure.

History of Trash Bridges

Engineers have been experimenting with bridges made from recycled materials since the 1990s. Bridges constructed with plastic have been embraced by the U.S. Army, in which the army has used plastic material bridges at Forts Bragg, Leonard Wood, and Eutsis. Similar civil projects have also been implemented in Europe, including a 90-foot bridge extending over the River Tweed near Edinburgh, Scotland.

How It Works

A New Providence, New Jersey-based company, Axion International, commercialized plastic technology developed at Rutgers University to make these projects a reality. Essentially, the company melts down and remolds plastic waste and turns it into eco-friendly building material that is suitable for construction and infrastructure projects of various types.

In this process, plastic waste is mixed with other scrap materials, including glass fibers with polystyrene and polypropylene. These materials are heated to just below melting point to make them form a strong, cohesive material.

Benefits of Trash Bridges

Bridges constructed from plastic waste represent a long-term, lower-cost alternative to traditional methods that use costly steel and concrete. These types of bridges don’t rust, rot, or attract pests, or need to be painted. These bridges are also significantly faster to construct and take less of a toll on the natural environment.

“We were able to complete construction on-site in just two weeks,” said Steve Silverman, Axion’s president and CEO about the bridge in Edinburgh. “Putting the pieces together, in fact, took only four days out of that process, he said. “The remarkably fast erection time for a 90-foot bridge is a major benefit.”

Future Applications

Some engineering professionals believe that trash bridges are the answer to America’s growing pollution problem and its persistent bridge infrastructure issue. The performance of these recycled plastic material bridges make them effective for new construction projects, harsh marine environments with lots of moisture, and in regions susceptible to earthquake damage. Although the initial cost of using these materials may likely be higher in the beginning because of the highly specialized processing methods, they promise long-term durability and enduring sustainability.

Axion predicts that America’s secondary roadways stand the most to gain from recycled plastic bridges that span approximately 15 to 25 feet long. When these projects first get underway, the general public perception may be that bridges formed from plastic waste are not safe or stable enough to support heavy trucks and SUVs. However, the U.S. military can vouch for these bridges performing effectively with even 120-ton locomotives on top of them. And with the amount of plastic waste being discarded and collected in America every day, it seems that the trash bridge industry won’t be running out of supplies anytime soon.

Photo credit: Keith Daly and U.S. Army Environmental Command via Flickr