The Virginia Department of Transportation is on a recycling tear. Not satisfied with mere cans and bottles, the agency is recycling an entire stretch of Interstate 81 in Augusta County. Believed to be the first time that three different road recycling procedures have been used in combination, the project will take two-thirds less time than conventional road reconstruction. It will also save millions of dollars, and reduce the carbon footprint associated with construction vehicles and equipment.
Recycling a Road
The 3.7-mile long stretch of road requires more than a surface treatment. The roadbed is up to two feet deep and has to be rebuilt down to the bottom in the right lane, which gets the heaviest use. The twelve-inch foundation in the right lane will be re-compacted, and the layer of asphalt in the right lane will be taken out and put through an on-site mobile processor, then reapplied. The left lane takes less punishment, so the asphalt in the left lane can be pulverized in place, then strengthened and compacted. Then a fresh asphalt surface will be laid down over both lanes.
Lowering the Carbon Footprint of Road Reconstruction
In addition to conserving materials, the recycling operation will cut down on carbon emissions from the trucks that would normally be needed to schlep old materials offsit, and bring in the new stuff. The operation requires a narrower workspace than conventional reconstruction, so it also eliminates the need to temporarily widen the the road, which would otherwise be required in order to keep two lanes of traffic open. Combined with the quick pace of the work, that reduces the chance of excess green house gas emissions due to traffic tie-ups.
Highways and Sustainability
Recycling is just one area in which the nation’s roadways are becoming showcases for a sustainable future. Harvesting solar energy and piezoelectric energy are two other potentials. Using right-of-ways to grow weedy biofuel crops is also under discussion, and out in the midwest they’re even using a stretch of Interstate 44 to test a bio-oil refined from pig manure as an asphalt binder – but don’t hold your breath. Not all that much is going to happen until Congress gets off worrying about things that don’t need to be fussed over, at least not on a priority basis, and starts getting around to the nitty gritty of governing, such as fixing roads and stuff like that. Sure, it’s not particularly glamorous and it won’t get you that sound bite, but it’s still got to be done.
Image: Interstate 81 in Virginia by taberandrew on flickr.com.
Tina Casey specializes in military and corporate sustainability, advanced technology, emerging materials, biofuels, and water and wastewater issues. Tina’s articles are reposted frequently on Reuters, Scientific American, and many other sites. You can also follow her on Twitter @TinaMCasey and Google+.