The arch was probably introduced to provide unusual girder depth at center for this extraordinarily long span and to eliminate redundant material at the ends. In addition, only a minority of concrete through girders use a slab rather than floor beams to support the roadway. The girders are also nicely decorated.
Architectural Description: The concrete through girder has a pair of large beams which flank the roadway and whose reinforcing rods are interlocked with those of either floor beams or of a slab deck. Because of its greater rigidity, the through girder can be extended beyond the T-beam's ordinary span length. In most cases, though, it has been preferred over the T-beam only when headroom is critical, i.e; where the roadway is so close to stream level that girders, which carry some of their load above the roadway, provide greater assurance against obstructing the watercourse.
CR 700E Concrete Bowstring
(Parke County, Indiana)Concrete girder bridge over North Branch of Otter Creek on CR 700EOpen to traffic
Rosedale Concrete Bowstring
(Parke County, Indiana)Concrete girder bridge over North Branch of Otter Creek on Rosedale RoadOpen to traffic