Bridges built from recycled plastic

FORT BRAGG, N.C., July 2 (UPI) -- A New Jersey company has developed a system to make bridges from recycled materials that are strong enough to support a U.S. Army tank.

Axion International Holdings, of Basking Ridge, N.J., said the engineers constructed a pair of bridges made entirely from recycled plastic products at Fort Bragg, N.C., and had M1 Abrams tanks driven across the spans.

The M1 Abrams, manufactured by General Dynamics, weighs nearly 70 tons, making it too heavy for the vehicle to use most standard bridges and roads.

Axion, in a release, said its composite technology withstood several tank crossings during the tests June 11 at Fort Bragg.

An article on the U.S. Army Corps of Engineers Web site said its Construction Engineering Research Laboratory was involved in the design and building of the test structures. Other U.S. Department of Defense officials were on hand for the testing.

"The first crossing was greeted with a big sigh of relief from some of us and a hardy round of applause from about 30 people in attendance," Richard Lampo, a CERL materials engineer and leader of the project, said in the article.

The company said its new bridges are made entirely from recycled consumer and industrial plastics. The two test thermoplastic spans were made from more than 170,000 pounds -- said to be the equivalent of more than 1.1 million 1-gallon milk jugs -- of recycled plastic. The structures are less expensive to build than traditional wood timber bridges often used on U.S. military bases.

"This represents a truly historic event for both structural engineers and environmentally conscious individuals across the nation," Axion Chief Executive Officer James Kerstein said in a company release.

"Not only are these bridges able to support the weight of a M1 Abrams tank, they are less expensive to build than wooden, concrete or steel bridges and are designed using higher-quality 100 percent recycled structural solutions in a manner that is nearly maintenance-free and eco-friendly."

Axion said its bridges incorporated the company's patented structural materials made from recycled plastic and a patent-pending I-beam design. It also claimed speed of installation and reduced costs for construction and maintenance as benefits.

The tests indicated the structures held up well under both moving and static weight loads and withstood stresses caused when the M1 operator applied the vehicle brakes while on the bridge.

Darryl Butler, a civil engineer with Fort Bragg's Directorate of Public Works, said: "We expect the advantages of the plastic lumber bridge will be lower maintenance costs and the ability to meet long-term training needs. The potential for this innovative material is only limited by the commander's requirements and the mission."

Axion said it developed its patented process in conjunction with researchers at Rutgers University. It says the resulting products are "ideal replacements" for construction materials such as wood, steel or concrete.