Standard prestressed girders

In the early days of prestressed concrete bridges, each designer developed their own optimized girder section. This was too expensive, because custom girders were designed for each project. Later, standard sections and strand layouts for prestressed concrete bridge girders were developed, which greatly simplified the design and fabrication.

United States
In the United States, the AASHTO and PCI developed standard girder sections Types I through IV in the late 1950s and Types V and VI in the early 1960s. As the technology of prestressed concrete design and construction advanced, FHWA sponsored a study to evaluate existing standard girder sections and to determine the most efficient girders in late 1970s. The study concluded that bulb-tees were the most efficient sections. As a result, PCI developed the PCI bulb-tee standard, which was endorsed by bridge engineers at the 1987 AASHTO annual meeting. These cross sections are also cost-effective with high-strength concretes for span lengths up to about 60 m (200 ft).