The appearance of distress in the form of cracking in any concrete structure is one of concern and consternation to all parties involved. It is evidence of an unfavorable stress condition and if serious enough could affect the structure's integrity. Cracking may occur for a number of reasons but usually is the result of the interaction of several causative factors. These factors taken individually may be minor but when superimposed can result in distress. This paper presents documentation of problems that have led to cracking in post-tensioned concrete box girder bridges in Europe as well as in the United States. 1t discusses cracking resulting from inadequate flexural and shear capacity, thermal stress cracking, and cracking resulting from tendon curvature and tendon misalignment. Also discussed are possible retrofit measures. The intent of this paper is to bring these problems to the attention of the engineering and construction professions with the hope of precluding their recurrence.
