Temperature Distributions in Composite Bridges

Variations in temperature within a typical interior deck-stringer section of a composite-girder highway bridge are investigated for mid-Missouri weather exposures. The exposures correspond to ambient air temperature extremes and were selected from National Weather Service data for the period 1946 through 1965. Equations to simulate these weather extremes and a finite element analysis are used to calculate bridge temperatures as a function of time. The results show that the temperature at the top of a bridge deck may be as high as 150°F (66°C) for a midsummer day and as low as -10°F (-23°C) for a cold winter day. The temperature differential between the top and the bottom of the deck for a hot day was 39°F (22°C) and for a cold day was 31°F (17°C). The maximum deck temperature occurred at 2:00 p.m. for the hot day and at 1:00 p.m. for the cold day. The minimum deck temperature occurred at 4:00 a.m. for both the hot and the cold day.