Efficiency of the latest prestressed concrete bridge girder designs being used in the United States was evaluated. Bridges built with pretensioned !- and T-sections for spans in excess of 80 ft (24.4 m) were considered. Information on current designs was collected from selected highway agencies and producers throughout the United States. In all states surveyed except California, the most economical bridges for spans of 70 to 130 ft (21.3 to 39.6 m) were constructed with pretensioned bridge girders. Precast, prestressed bridge girder sections inventoried were analyzed on three efficiency scales. Bulb-T's, Colorado, and Washington girders were more structurally efficient than AASHTO-PCI girders. Cost analyses were performed on existing Bulb-T's, Colorado, Washington, and AASHTO girders, and on their modified counterparts with 6-in. (152 mm) thick webs. Parameters included girder span, girder spacing, deck thickness, and concrete compressive strength. Based on relative unit costs for in-place materials and labor, cost charts were prepared. All girders were compared using optimum cost curves. Bulb-T's were found most cost-effective with estimated cost savings of 17 percent on the in-place cost of girders and deck compared to the AASHTO girders. Next most cost-effective sections were the Washington Series girders. Modified Bulb-T's are recommended for use as national standards.
