‘In Place Recycling’ has environmental benefits for repaving
[caption id="attachment_27257" align="alignright" width="360" caption="A CIR “train” repaves Rt. 36 near Chester, California."][/caption]
CITY OF NAPA, SONOMA COUNTY – The city of Napa and Sonoma County transportation departments have teamed up to sell an ultra-green, inexpensive way of repaving roads to Bay Area transportation agencies.
With the degeneration of county roads in the news the timing couldn’t be better for a demonstration of Cold In Place Recycling, a repaving technology that grinds up and reuses existing road aggregates and asphalt.
The joint project is funded by a $2 million grant from the Metropolitan Transportation Commission’s Climate Initiatives Program.
“We got a lot less than we asked for,” said Sonoma County pavement preservation manager Stephen Urbanek, “but it’s enough to get pavement management issues into the conversation when it comes to greenhouse gas reduction.”
Cold In Place Recycling (CIR) was enabled by advances in grinding equipment, he said. What normally takes place at a recycling plant can now happen at the project site as part of the repaving process.
The upper two to four inches of existing asphalt concrete pavement are pulverized in place and mixed with recycling emulsifying agents, then graded and compacted just like new asphalt concrete.
“CIR is a wonderful process, green in so many different ways,” said Mr. Urbanek.
It’s also half the price, according to James Emerson, project manager for Pavement Recycling Systems, a contractor in Mira Loma, near Riverside.
“CIR has been in use in Europe for a number of years. They don’t have the resources we do so recycling is vital,” said Mr. Emerson.
The technology is in wide use throughout the U.S. and Southern California – Caltrans has dedicated $15 million a year to CIR – but it hasn’t yet found its way to the Bay Area, where repaving costs are already unusually high.
CIR reduces the cost to $30 to $40 per installed ton versus $75 to $100 for traditional methods, experts said. And the material can be recycled over and over again.
“The paving material bought by a city or county should be considered an asset. But it’s normally torn up and carted away when the road needs repaving,” said Mr. Emerson. “Often it’s milled and a percentage put back into hot asphalt, which is sold back to the city or county.”
Although CIR can’t pave new roads or other surfaces, for repaving it can eliminate nearly 80 percent of greenhouse gas emissions from aggregate mining and asphalt production operations compared to starting from scratch, officials said. It also eliminates the need for trucks hauling old material off the site and new material onto the site.
“It’s a great application, providing you have the right qualities in the existing asphalt,” said Mike Llamas, vice president of construction for Ghilotti Bros. in San Rafael.
“Not only does it give you a quality project, it reduces stress on the surrounding roads and city arteries, which are otherwise exposed to heavy truck traffic on and off the site. It also reduces congestion,” he said.