During the demolition of a 23-year old concrete bridge in Reno, a large number of plant-cast prestressed concrete box girders with a length of 69' were recovered in good condition. Six of the girders have been donated to the University of Nevada, Reno (UNR), for research purpose. These girders provide an excellent opportunity to study different aspects of the behavior, design, repair, and fatigue life of existing structures. Research funds have been received from the Department of Energy to test two girders to determine their actual stiffness and strength and to conduct limited studies on the repair of the girders. The primary objective of this proposal is to study four additional girders to determine (1) the actual prestress forces, (2) the extent of chloride contamination after 23 years of exposure to deicing salt, (3) the effect of low-level damage on the remaining life, and (4) appropriate repair techniques for girders damaged by collision, and to investigate the fatigue performance of the repaired girders.