Thursday, December 13th, 2012
The first bridge in California that’s made of recycled plastic was dedicated last Friday. The 10-ft wide by 25-ft long footbridge spans an arroyo to replace a bridge washed out by high water. The first “feet” crossing the bridge were actually hooves, four of them, each the property of a horse named Webster. Reports indicate he was not interested in the ceremony or
Local residents, on the other hand, were quite happy to have a bridge again, and not at all surprised to see a horse on it. The Santa Rosa Arroyo Bridge is part of a network of equestrian trails in the Santa Rosa Valley of Ventura County, CA.
The bridge’s recycled plastic structural components are made by Axion International Holdings of New Providence, NJ. OK, but are they strong enough for horses? Well, the three Axion bridges at Fort Bragg, NC are crossed by 70-ton M-1 tanks, and have been for a few years. Horses are no problem.
The structural thermoplastic material Axion uses was developed by scientists in the Materials Science and Engineering Department of Rutgers University (New Brunswick, NJ). Axion CEO Steve Silverman told the Ventura County Star that the company combines laundry, shampoo and other high-density polyethylene (HDPE, Resin Code #2) bottles with scrapped car bumpers made from polypropylene(PP, Resin Code #5), which is molded into products such as railroad ties and bridges using patented production technology.
Advantages of Axion’s Struxure material over traditional metal include the combination of light weight with high strength, plus being impervious to environmental factors like sunlight, water, insects, chemicals, and temperature changes. The lightweight, pre-made components allow the bridges to be usually installed in a day.
Bridge engineer John Dickerson of VCE Services in nearby Ventura, CA who designed the bridge said, “I think it’s fantastic, because a long time ago when I graduated from college, a professor told me that sooner or later, they would use plastic and it would be one of the best building materials there is. It’s here now, and it’s going to be used for a very long time.
“I plan to use the plastic material for projects in and around the ocean, where steel corrodes, concrete cracks, and wood warps and eventually erodes because of insects. You couldn’t use a better material around saltwater because it’s totally immune to anything saltwater can possibly do to it. The applications for this material are almost endless,” Dickerson added.