Behavior of composite bridge under effect of thermal loading

Nowadays, composite box-girder bridges are extensively present in civil engineering works due to its higher torsion stiffness, higher flexural capacity, rapid construction, economics, and long span capability. This thesis deals with the behavior of composite box-girder bridge under the combination of environmental thermal loads of solar radiation, atmospheric temperature, and wind speed. It is based on temperature and thermal stress results, which recorded hourly from the full-scale experimental composite box-girder bridge segment constructed on a campus of Gaziantep University and numerical thermal analyses. In this thesis as a first approach a study of the effect of mutual irradiations between the exposed bridge surfaces and the ambient air concurrently in addition to the radiation heat fluxes that generated inside the cavity of the composition system on the thermal performances of the composite box-girder. The hourly variations and the magnitudes of the numerical temperatures matched well with the experimental ones. Additionally, the important parametric investigations are conducted to emulate the influences of the orientation of the bridge's longitudinal axis and geometrical configuration of a bridge and the thickness of the asphalt in addition to the season on the thermal response and stress distributions. On the other hand, a series of statistical analyses are implemented to submit the correlation between the important parameters of the environmental thermal loads with maximum vertical and horizontal temperature and thermal stress gradients throughout the experimental period of the current study. Furthermore, in this thesis the study provided for the first time about the impact of shear connector's number and arrangement at the concrete-steel interface on the hourly vertical thermal movements under the different environmental thermal variables of Gaziantep with emphasis on the degree of composite interaction. The hourly findings related to the total number and rearrangement of headed studs under partial interaction are presented to enable bridge engineers for economically as well as to the extent the design life of such constructions as regards to climatic impacts.