Most cities want to reduce their carbon footprint these days. Stockton (www.stocktongov.com), in the San Joaquin Valley of California, is no exception to the new enviro-friendly thinking. So, it teamed with George Reed Inc., a Central Valley paving contractor, to try a warm-mix asphalt technique rather than the traditional hot-mix procedure on a residential paving project recently.
A bit of research indicated the touted benefits of warm-mix asphalt technology by MeadWestvaco Corporation, an east coast company. Using a chemical additive called "Evotherm" it had developed, MeadWestvaco claims their warm-mix technology enables asphalt mixes to be produced at temperatures more than 100 degrees lower than traditional hot-mix asphalt applications. And that these lower production temperatures could reduce fuel consumption, greenhouse gas emissions and nitrogen oxides that lead to photochemical smog, plus a significant reduction in acid rain-causing sulfur dioxide. The technology is said to be odor free, reducing community response to ongoing road construction.
Dropping a temperature of over 300 degrees Fahrenheit, down to about 204 degrees or less, is significant. Apparently, the city of Stockton liked the warm-mix technology.
"We are very pleased with the successful results of this project," said Gordon McKay, deputy public works director - operations and maintenance for Stockton, in a press release. "This is the first time we have tried warm-mix asphalt in Stockton. It is a next-generation technology that produces durable roads while significantly reducing the environmental impact of construction on our community, something that we are striving to do as part of Mayor Chavez's commitment to the U.S. Mayors Climate Protection Agreement of 2005."