The Georgia Department of Transportation has wrapped up work on what should be another weapon in its wintry weather arsenal — a “salt barn” off Interstate 985 between Oakwood and Flowery Branch. Plans call for the DOT to fill the building with salt in the fall, district spokeswoman Teri Pope said. The state decided to put up salt barns across the state as part of a response to snowstorms that crippled traffic in and around Atlanta in the winter of 2013-14.