| In the years since the introduction of the CAN/CSA S6-00 "Canadian Highway Bridge Design Code", the types of prestressed concrete girders available in Atlantic Canada have changed. The new code introduced increased concrete cover requirements that made the existing girders obsolete. The alternative girders introduced locally were imports from the eastern United States. A family of girders had recently been developed there called the New England Bulb Tee girder. The formwork used for this type of girder allows the depth of girder to vary between a depth of 1000 mm and 1800 mm. The wide range of depths available increases the choices to bridge designers, but also increases the variables in selecting the optimum depth.; Design aids are available to American designers following the provisions of the AASHTO code, however a literature search failed to reveal any such design aids available to engineers for girder design according to the provisions of the Canadian code. Graphs have been developed by PCI (Prestressed Concrete Institute) for many standardized girders shapes, but they have been developed based on the AASHTO design codes and use a different set of assumptions. This project produced design graphs and tables, which will allow the user to quickly identify the depth of girder, girder spacing and number of strands that satisfy the Canadian code defined stress limitations. To be particularly relevant for the Atlantic Canadian market, the graphs were developed for the New England Bulb Tee, currently the most prevalent precast concrete girder in the region. (Abstract shortened by UMI.)... |
