A Camber Study of MnDOT Prestressed Concrete I-Girders

This project investigated the relationship between predicted and measured girder cambers. For more than three years, researchers collected camber data on girders of various depths and lengths from the time of strand release until shipment to the job site. Researchers used three camber prediction methods to compare with the measured values: PCI method, Branson's timestep approach, and "CRACK" analysis program by Ghali et. al. The Branson time-step approach resulted in the closest predictions to the measured cambers. The PCI method, although simple, gave reasonable long-term camber results compared with the more detailed methods.Minnesota Department of Transportatio