Experimental analysis of temperature gradients in concrete box-girders

• A full-scale experimental box-girder segment was constructed and instrumented.
• Temperature gradients were analyzed in concrete bridges under environmental loads.
• The recorded maximum vertical and lateral gradients were 19.7 °C and 19.0 °C.
• Formulas were proposed to predict maximum temperature gradients in concrete girders.
• Simple formulas were proposed to predict the mean temperature of concrete bridges.

This paper describes the construction and instrumentation of an experimental box-girder segment, aiming to analyze the temperature distributions in concrete bridges under the fluctuation of air temperature and solar radiation thermal loads. The instrumentation included air temperature, solar radiation, and wind speed sensors in addition to 62 thermocouples, while data acquisition continued for more than one year. The maximum vertical temperature gradient was recorded in June, while the maximum lateral gradient was recorded in December. Empirical formulas were proposed to predict the maximum vertical and lateral temperature gradients, in addition to the daily maximum and minimum mean temperatures of the bridge.