The Nevada Department of Transportation is switching the kind of cement it uses on roadways to reduce greenhouse gas emissions.
A spokesman said the change to Portland Limestone Cement will cut emissions by 4,000 tons a year.
The change was worked out by NDOT and the Associated General Contractors of California and Nevada. The emissions reduction comes from the process used to make the cement. Traditional cement is produced by heating limestone and clay in a kiln then grinding it to a fine powder. The process produces about one pound of carbon dioxide for every pound of cement.
The limestone cement process replaced some of the binder material with raw limestone, cutting carbon emissions in the production process by 9 percent.
The new cement formula performs comparably to standard cement.
NDOT officials say the department uses about 45,000 tons of cement each year to build, maintain and upgrade roads, bridges, sidewalks, retaining walls and other concrete structures. They said that is a significant reduction since transportation contributes an estimated 35 percent of the state’s total greenhouse gas emissions, more than any other source.