Transverse thermal stresses in concrete box cross-sections due to climatic exposure

Spatial and temporal temperature variations in a concrete structure due to variations in the surrounding climate will produce movements which, if restrained, may induce stresses in the structure. To get a better understanding of transverse thermal stresses due to climatic effects in concrete box cross-sections, the FE simulations in this study have been performed using extensive climatic input data directly or by using simplified methods to simulate the temperature and resulting stress fields in a section of the hollow concrete arch of the New Svinesund Bridge. Studies of other cross-sections with varying depth, width and wall thicknesses have also been performed to investigate the geometrical influence. The results reveal an overestimation of the maximum thermal tensile stress when using a linear temperature differential approach compared with the direct use of climate data that includes the non-linear part of the temperature distribution. The effect of depth, width and orientation is negligible compared with variations in thickness between slabs and walls. For box sections with slabs/walls having different thicknesses, the transverse thermal stresses will be significantly larger in the thinner members, irrespective of the actual orientation and position of the member.