historic context of maryland highway bridges built between 1948 ...

SECTIONFOURPost World War II Technological Developmentsto have been cast in place as part of the bridge structure. Steel trusses were also used to supportprefabricated segments as they were installed (Lin and Kulka 1975: 494-495).Early precast beam and girder bridges were simple fifty to 100 foot spans. These short spanswere later improved upon by the placement of reinforcing bars over pier locations (Lin andKulka 1975: 495-496). An example of a pretensioned concrete bridge is Bridge 0802200, theMD 225 bridge over Mattawoman Creek (Maryland State Highway Administration 2003).5.3.7 Reinforced Concrete Bridges(See below for bridge counts.)In Maryland, reinforced concrete bridge plans were standardized early in the 20 th century. Thisexplains the large number of small 20 th century concrete bridges of this type found within thestate. Reinforced concrete bridges were used liberally on the Eastern Shore and the technologywas used in the constructions of small, long and movable span bridges (Spero and Berger &Associates 1995: 29-30).An example of a reinforced concrete slab bridge is the Horseshoe Road over Stone Creek Bridgelocated near Octoraro, in Cecil County ((Legler and Highsmith 2002: Cecil County).5.3.8 Concrete Rigid Frame Bridges(See below for counts.)The first concrete rigid frame bridge constructed in Maryland is dated to 1934. Following theclose of World War II construction of this bridge type mushroomed. These bridges were bothcast and constructed from prefabricated components and cast in place. Casts consisted of singularor multiple sections. Smaller structures were slab-beam types reinforced with tension steel.These structures were very stable, did not feature arches and could be buried, constructed atgrade or constructed above the ground surface (Parsons, Brinckerhoff, Quade & Douglas 1997:3-23). An example of a concrete rigid frame bridge is the MD 97 bridge that spans Big PipeCreek in Carroll County, Maryland. This bridge is located near Union Mills, Maryland and wasbuilt in 1934 (Legler and Highsmith 2002: Carroll County).Counts of Concrete Bridges Constructed Between 1948-1960Concrete Arch: 2Concrete Slab: 28Concrete Beam (including Tee Beam): 14Concrete Rigid Frame: 20Concrete Girder or Box Beam: 18(Maryland State Highway Administration 2003).\15-SEP-11\\ 5-6