Ultimate Flexural Capacity of a Severely Damaged Reinforced Concrete T-Girder Bridge

Rational and precise evaluation for ultimate flexural capacity is essential for accurate prediction of the safety margin and overload capacity of existing bridges. One of the spans of a 28- year-old distressed simply supported T-girder bridge with a span of 20 m was severely damaged, and the decision to replace it with new one was made. A field destructive load test of this distressed span was performed. A nonlinear finite-element model technique was used to predict the failure load and retrace the load-versus-deflection response. The ultimate flexural capacity obtained by the destructive load test was compared with the results of a limit-states design method. The comparison revealed that the ultimate flexural capacity of the distressed bridge was more than the bending moment produced by the combined effect of self-weight and overloaded vehicles plying over it, which explains why the bridge supported overloaded vehicles for many years. (C) 2017 American Society of Civil Engineers.