Long-Term Impacts of Temperature Gradients on a Concrete-Encased Steel I-Girder Experiment—Field-Monitored Data

Abstract

This article delves into an investigation of an experimental steel I-girder section encased in concrete and its instrumentation for the purpose of analyzing temperature distributions in concrete bridges. The study aims to examine the effect of differing air temperatures and thermal loads resulting from solar radiation. Structural health monitoring sensors, including a range of temperature sensors, were connected with the girder to monitor the structural performance using the data acquisition system constantly. The collection of experimental data took place during an exceptionally cold season, and the results of the study revealed both the lateral and vertical distribution of thermal gradients, as well as the fluctuations in these gradients over time. On the premise of the accumulated thermal data, empirical equations were suggested in order to forecast peak lateral as well as vertical temperature gradients, in accordance with the girder’s highest daily and lowest mean temperatures. This temperature variation may lead to longitudinal expansion and contraction in the structure during seasonal variations.