Modeling daily temperature effects on a concrete bridge in the ukrainian climate conditions

Introduction. Temperature effects on bridge superstructure are a constant factor influencing their performance. Due to low thermal conductivity of concrete, temperature gradients develop across cross-section of the structure, causing additional deformations and internal stresses. With global climate change and rising average annual temperatures, this issue has become especially important. Problem statement. Underestimating temperature effects during bridge design and operation can lead to structural damage, reduced service life, and decreased reliability. Although European and American standards include models for temperature effects, Ukraine lacks comprehensive studies considering local climate conditions. A significant gap exists in experimental data, which complicates adapting or developing accurate design models. Purpose. The main goal is to develop and validate a mathematical model for temperature distribution in concrete bridge superstructure over a daily cycle, specific to the Ukrainian climate. The model incorporates external climate parameters and material properties. It is validated by field measurements to improve accuracy in estimating temperature-induced stresses and enhancing structural reliability. Materials and methods. The study analyzes the impact of climatic factors on the temperature of concrete bridge structure under Ukrainian climate conditions. Both analytical and numerical modeling were used. Experimental temperature measurements were taken on the span surface, combined with theoretical temperature modeling over a daily cycle using the finite element method. The stress-strain state of the span elements was also analyzed.