Performance assessment of FC girder bridges in Alberta.

A large number of precast prestressed concrete multi-girder bridges were constructed in Alberta in the early 1960s. Major benefits of this type of construction included the elimination of the cast in place concrete bridge deck and the accelerated pace of construction in erecting the bridge. However, after providing 10 to 20 years of service, some of these bridges started to form longitudinal cracks in the deck directly over the girder joining shear key locations. Once a crack was formed in the shear keys, salt and water would penetrate the wearing surface and weaken the shear key grout. This brought about concerns regarding adequate load sharing among the girders and corrosion of the prestressing tendons within the girders. An extensive survey was undertaken to observe the longitudinal cracking on these bridge decks. The objectives of the field survey were to look for possible trends or relationships between various influencing parameters and the performance of these bridges. Field data were obtained from a visually selected sample survey and a comprehensive bridge record survey based on Alberta Transportation (Government of Alberta) bridge files. The parameters investigated for influence on bridge performance were span length, span width, bridge skew, service age, and traffic volume. Finally, the rehabilitation schemes used on these bridges in the past are described, and the strengths and weaknesses of each rehabilitation strategy are discussed. [ABSTRACT FROM AUTHOR]