Monitoring and analysis of temperature distribution in reinforced concrete bridge box girders in Vietnam

Vietnam's current bridge design code is based on AASHTO LRFD Specifications. Many field survey projects are being conducted to localize some environmental action data. This paper presents a temperature monitoring project on three large concrete box girder bridges in different climate regions of Vietnam, which have recently seen increased construction in the country. Additionally, some results of a data regression analysis to build predictive formulas on temperature distribution in such bridges are also introduced. In this data analysis, the solar radiation is calculated based on the air temperature. The good agreement of prediction and monitoring data shows that this method is appropriate, especially for Vietnam’s condition, where the air temperature data are available for every region but not the solar radiation data. Furthermore, an estimation of extreme values for temperature gradients in the top and web slabs, as well as in the entire section, using the Generalized Pareto Distribution (GPD) has been conducted. This estimation indicates that webs in box girders can be subjected to very large horizontal temperature gradients.