STONEHAM ARCH BRIDGE HIGHWAY 73

This suspended arch bridge is an aesthetically pleasing solution to a unique site requirement. The choice of hot-dip galvanizing was preferred by the engineer because of its durability and cost compared to Cor-ten steel in this highly corrosive environment. The resulting bridge is a beautiful and cost-effective marriage between structural steel and reinforced concrete.

"The resulting bridge is a beautiful and cost-effective marriage between structural steel and reinforced concrete."

The arched bridge design, unusual for a highway overpass, was chosen primarily to overcome two problems; uneven and rocky field conditions, as well as the very obtuse angle at which the road passed over the highway, which did not fit well with typical overpass construction. Steel beams were chosen for the deck because of the lower weight as compared to concrete. These beams were also designed to be galvanized rather than metallized, again, for economic and performance reasons. As for the reinforcing steel, the choice of hot dip galvanizing was obvious since the concrete arches needed to be protected both structurally and aesthetically.

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