Impact of Extreme Summer Temperatures on Bridge Structures.

摘要

Climate change and its effect on weather in the United States is a well-documented phenomenon. In particular, extreme heat waves have become more intense, more frequent, and longer lasting, especially in the southern United States. As with much of America's transportation infrastructure, prestressed concrete bridge girders experience the effects of these heat waves. Uneven heating of optimized bridge girder sections results in large non-linear temperature gradients. In this study, temperature was monitored in three different AASHTO I-girders to determine the vertical and transverse temperature gradients in a pre-deck placement condition. It was determined that the current design standard, which uses a non-linear vertical thermal gradient, was inaccurate in both shape and magnitude for girders Type IV and smaller in this condition. Transverse gradients were also recommended as none are included in design standards. Using three dimensional modeling, this study also sought to understand the response of the girders to non-linear temperature gradients and if they should be accounted for in girder design.