The Grist Mill Bridge, a 75-ft single-span bridge in Hampden, Maine, is the first in the nation to use composite tub girders with no concrete reinforcement in the superstructure, say officials. The five fiberglass-reinforced polymer (FRP) composite beams and other corrosion-resistant features are also expected to extend the design life of the hybrid composite concrete bridge by at least 100 years, according to Wayne Frankhauser, bridge program manager for the Maine Dept. of Transportation.  

Recently opened to traffic, the bridge is part of an $8.9-million Hampden road reconstruction and paving project along a two-mile stretch of 1A scheduled for final completion in June. The two-lane bridge carries about 6,400 vehicles per day over the Souadabscook Stream, due north of downtown Hampden.