Document Type : Research Paper


Departement of Civil Engineering, College of Engineering, University of Al-Qadisiyah, Iraq.


In this article, a prototype empirical section of the composite girder was performed to verify the temperature distributions and the changes in concrete bridges under environmental thermal stresses. T-Beam composite section was placed directly subjected to environmental conditions to endure the change in convection, the convection includes solar radiation, surrounding air temperature, and wind speed. In addition, this paper includes the 3D finite-element thermal studies represented by the COMSOL MULTIPHYSIC program, with particular reference to the influence of several parametric studies that are represented by changes in concrete thickness, adding asphalt layer, and finally change the value of wind speed. The section is prepared with fifteen thermocouples in different places in steel and concrete in the actual and theoretical models to evaluate the temperature distribution inside the composite bridges and their effects in the selected points. COMSOL MULTIPHYSIC showed a good ability to simulate convection, heat conduction, and radiation within the surrounding environment. Such as the thermocouple (TC3) the minimum temperature was 33.18 oC, 33.29 oC, the maximum temperature was 63.67 oC, and 62.77 oC for experimental and theoretical results respectively while the maximum and minimum difference between experimental and FE temperatures is 2.96 and 0.099 for TC3 respectively. Therefore, it can be said that all the thermocouples results showed a good agreement between practical and theoretical results.