Experimental and numerical study of temperature gradient effect on behavior of steel-concrete composite bridge deck

To investigate the effect of temperature gradient on the behavior of steel-composite deck slabs, a temperature gradient loading device prepared by the electric auxiliary heat principle was used. The steel-composite deck slabs of steel truss stiffened girder suspension bridges were used as reference objects to carry out indoor temperature gradient tests on the steel-composite sections under different boundary constraints. A refined finite element model with thermal-force sequential coupling was established to calculate the vertical temperature gradient distribution pattern. The extreme stresses under different temperature gradient conditions were compared and analyzed. The results show that the test loading device of this paper can favorably simulate the temperature distribution of the structure under the condition of sunlight radiation on the top surface. The test results are in good agreement with the calculation results of the refined finite element model. The steel-hybrid bridge deck slabs under different restraint conditions are affected by the vertical temperature gradient obviously, and the effect of thermal stress cannot be ignored. The extreme stresses of the concrete slab and steel beam are almost linearly related to the vertical temperature gradient of the structure. © 2021, Editorial Office of Journal of Building Structures. All right reserved.