08-16-2017, 09:57 PM
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Concrete Bridges
A. EMIN AKTAN, Drexel University
MICHAEL P. CULMO, CME Associates, Inc.
DAN M. FRANGOPOL, University of Colorado
CATHERINE W. FRENCH, University of Minnesota
BASILE G. RABBAT, Portland Cement Association
MARY LOU RALLS, Texas Department of Transportation
HENRY G. RUSSELL, Henry G. Russell, Inc.
DAVID H. SANDERS, University of Nevada
JOSEPH SHOWERS, Parsons Brinckerhoff
MAHER K. TADROS, University of Nebraska
STANLEY W. WOODS, Wisconsin Department of Transportation
abstract
Concrete is the most-used construction material for bridges in the United States, and indeed
in the world. The percentage of bridges built annually with the three major construction
materials is illustrated in Figure 1.
The application of prestressing to bridges has grown rapidly and steadily, beginning in
1949 with high-strength steel wires in the Walnut Lane Bridge in Philadelphia,
Pennsylvania. According to the Federal Highway Administration s 1994 National Bridge
Inventory data, as shown in Figure 1, from 1950 to the early 1990s, prestressed concrete
bridges have gone from being virtually nonexistent to representing over 50 percent of all
bridges built in the United States.
Prestressing has also played an important role in extending the span capability of
concrete bridges. By the late 1990s, spliced-girder spans reached a record 100 m (330 ft).
Construction of segmental concrete bridges began in the United States in 1974. Currently,
close to 200 segmental concrete bridges have been built or are under construction, with
spans up to 240 m (800 ft).
Late in the 1970s, cable-stayed construction raised the bar for concrete bridges. By
1982, the Sunshine Skyway Bridge in Tampa, Florida, had set a new record for concrete
bridges, with a main span of 365 m (1,200 ft). The next year, the Dames