Only mean temperature changes are generally considered in the design of concrete bridge superstructures. Because of daily changes in both ambient temperature and intensity of solar radiation, temperature differentials also exist in concrete superstructures. These temperature differentials induce stresses throughout the depth of concrete structures, which are generally not included in current design procedures. This paper describes the heat transfer processes that occur between the atmosphere and a concrete superstructure and also the climatic conditions necessary for the development of temperature differentials during both summer and winter temperature-time analyses, computed by using a one-dimensional heat flow analysis, indicate that the distribution of temperature throughout the depth of a superstructure is nonlinear and is a function of superstructure depth. Stresses associated with the nonlinear temperature gradients are described. These stresses can be several times those due to live load, specially in continuous systems. The stresses predicted from the idealized distributions are compared to those obtained by using the heat flow analysis. The results indicate that the idealized distributions have limited design value. Simple empirical design expressions are developed for both thermal stresses and curvature. These are based on typical climiatic data for summer and winter conditions and can be applied to a variety of cross-sectional superstructure geometries. An example of the stresses induced by thermal loading on a two-span box-girder superstructure is given. /Author/

Media Info

  • Media Type: Print
  • Features: Figures; References; Tables;
  • Pagination: pp 7-13
  • Monograph Title: Bridge design, testing, and evaluation
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00157807
  • Record Type: Publication
  • ISBN: 0309025826
  • Files: TRIS, TRB
  • Created Date: Sep 28 1977 12:00AM