The impact of temperature gradients on the stress-strain state of a reinforced concrete bridge: field measurements and modeling

Problem. The influence of temperature differences on bridge superstructures is often underestimated, even though such variations can cause cracks in concrete elements and ultimately reduce the bridge’s service life. In light of global climate change and increasing average air temperatures, this issue has become even more urgent. Goal. This article presents the results of temperature measurements taken across the cross-section of a concrete bridge. The aim of the study is to analyze the temperature distribution and assess its impact on the structural performance of the bridge. Methodology. Temperature measurements were carried out on a concrete bridge over the Tereblia River in Zakarpattia, Ukraine, in June 2023. A non-contact electronic pyrometer was used to record temperatures at several key points across the bridge cross-section. Measurements were taken in both the morning and afternoon to capture daily temperature changes. Results. The data revealed significant temperature differences across the bridge cross-section, with values reaching up to 11.4°C in the morning. The greatest temperature gradients were observed on the side exposed to direct sunlight and within the internal girders, due to heat transfer from the warmed bridge deck pavement. The study also highlights the substantial impact of these temperature differences on the stress-strain behavior of structural elements, leading to the development of internal stresses in the concrete. Originality. This research highlights the effects of temperature variations on the concrete superstructure of the bridge. Given the lack of comprehensive data on temperature-induced stresses in bridge elements for the climate of Ukraine, the study offers valuable insights into the challenges posed by climate change in bridge engineering. Practical value. The recorded data and the subsequent analysis of thermal stresses offer a foundation for improving the understanding of how temperature affects concrete bridges in the climate conditions of Ukraine. These findings are essential for improving the design, monitoring, and maintenance of bridge structures, contributing to their long-term durability and safety in a changing climate.