A 90 foot long bridge made from over 50 tons of recycled plastic crosses the River Tweed in Scotland and is strong enough to carry load bearing vehicles up to 44 tons. The Scottish bridge is the first of its kind built in Europe and makes up the longest spans constructed from recycled plastic.
Vertech Composites, the company behind the engineering of the bridge, partnered with many of the specialists that developed the US Army Engineers’ thermoplastic composite I-beam bridge in Fort Bragg, including the School of Engineering at Cardiff University and Rutgers University’s Advanced Polymer Center.
The team formed structural shapes from thermoplastic composite, manufactured by Axion International, with reduced cross sections (e.g. I-beams, T-beams) to decrease the amount of material in each component without compromising structural integrity. The efficient designs reduced the bridge’s cost and weight.
Axion International’s patented thermoplastic composite material uses post consumer recycled high density polyethylene that would otherwise head to landfills. The inherent properties of the material naturally resist rot, rust, and damage from pests. The material also requires no finish, little maintenance, and is 100 percent recyclable.
Vertech estimates the thermoplastic material’s life expectancy to be 50 years, which results in a $300 per square foot lifecycle cost savings when compared to standard building materials like treated timber.
By recycling the plastic into a high performance, sustainable building material, Vertech ensures that the waste remains local while contributing to meeting Europe’s environmental targets. The project demonstrates that in order to apply recycled content in significant quantities, the recycled materials need to be used at a civic scale.