ASPIRE is a quarterly magazine published by PCI in cooperation with the associations of the National Concrete Bridge Council. The editorial content focuses on the latest technology and key issues in the Concrete Bridge Industry.
Issue link: http://www.aspiremagazinebyengineers.com/i/306852
The Elk Avenue Bridge in Elizabethton, Tenn., completed in1926, is a Luten Bridge Company reinforced concrete arch, restored in 2003 by TDOT. Photos: Tennessee DOT. State Route 9 Bridge over the French Broad River was constructed in 1926. 46 | ASPIRE , Fall 2009 S TAT E T h e b e g i n n i n g s o f c o n c r e t e b r i d g e construction in Tennessee can be traced to approximately 1910. At the time, there were no formal bridge construction programs. Cities and counties usually funded individual projects. Prior to about 1910, bridges, depending on span lengths, were constructed of all timber, iron, or steel trusses with wooden decks, masonry filled arches, or masonry substructures with wooden beams and decks. The impetus for the initiation of concrete constr uction was two-fold. First, counties perceived that a new structural system utilizing concrete spandrel arches—both filled and open—while not less expensive than the other systems mentioned, offered the potential for less maintenance, even "a 100-year life." The second driving force was the establishment of several firms, many located in Knoxville that aggressively marketed concrete arch construction. The most notable of the companies was the Luten Bridge Company, based in Indiana. Daniel B. Luten was a graduate of the University of Michigan, later an instructor at Purdue University, and an entrepreneur who was a pioneer in the design and construction of reinforced concrete. An example of his work in Tennessee is the Elk Avenue Bridge over the Doe River in Elizabethton, constructed in 1926. The bridge was recently rehabilitated by the Tennessee Department of Transportation (TDOT) and was described in ASPIRE™, Fall 2007. The Tennessee Highway Department was established by the Legislature in 1915. The Legislature anticipated favorable action by the United States Congress on a pending bill that would provide federal aid for road construction. The federal law had a provision that each state was required to have a highway department suitably organized and equipped to discharge its responsibilities. The bill became law in 1916. From those beginnings, reinforced concrete played an integral and dominant par t in bridges designed and constructed by the new Highway Department staff. The first standard drawing, D-0-1, dated February 15, 1917, was for a concrete box culvert with 2- to 3-ft span lengths and depths from 1 ft 6 in. to 3 ft 0 in. for a 20-ft-wide roadway. Other standards that bear a similar date included the first slab bridge for span lengths of 12 ft 0 in. to 24 ft 0 in. and the first concrete deck girder bridge with a 32-ft length for a 16-ft 0-in.-wide roadway. The era of reinforced concrete had begun. It was followed by the development of standard wingwalls, abutments, piers, and bents to support the superstructures of bridges of all types of construction. In addition, there was a seemingly endless variety of concrete box and slab bridges, and concrete deck girder spans of varying lengths, skews, and roadway widths. The vast majority of concrete deck girders were standard simple spans assembled in series to form a bridge of needed length. However, by as early as 1928, certain bridges were constructed utilizing multiple-span, continuous tee-beam units with integral intermediate substructures. There were also more monumental designs, such as the State Route 9 Bridge over the French Broad River, an open spandrel arch bridge built in 1926. A Brief History of Concrete Bridge Construction in Tennessee by Edward P. Wasserman, Tennessee Department of Transportation by Edward P. Wasserman, Tennessee Department of Transportation State_Tennessee_fall09.indd 46 9/14/09 4:17:58 PM