Service life prediction method for concrete and prestressed concrete bridges under chloride-aggressive environments

The behavior of concrete and prestressed concrete bridges under chloride-aggressive environments during their service life is influenced not only by load (especially fatigue forces) but also by the corrosion environment. At present, the research of working performance and life prediction of bridges mainly focuses on the role of force or takes a single parameter as failure criterion, such as chloride ion concentration and steel bar depassivation. In this article, the service life prediction model of concrete and prestressed concrete bridges subjected to chloride-aggressive environments and fatigue is established, and the interaction of environmental effects and fatigue is taken into full account based on the mechanism of heat and mass transfer in porous media, the metal corrosion theory, and the classical mechanics theory. Taking depassivation as a demarcation point, the calculation method for the service life of concrete and prestressed concrete bridges is developed by analyzing the service life evolution process and determining the failure criterion. The service life of concrete bridges in coastal areas is calculated by the self-compiled program with MATLAB software (MathWorks, Natick, MA), and the results show good agreement with those in the project example. According to the results of the service life calculation with different increments of the number of fatigue loading cycles, ΔN, the increment of the number of fatigue loading cycles ΔN has an influence of no more than 5 % on the service life. This indicates that the calculation is converged and stable and that the calculation results are reliable. The service life of bridges is shortened with the increase of surface chloride concentration of concrete, daily vehicle traffic volume and load level, and the decrease of the concrete cover thickness. The study results are referred to predict the service life of concrete and prestressed concrete bridges under chloride-aggressive environments.

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  • English

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  • Accession Number: 01709345
  • Record Type: Publication
  • Files: TRIS
  • Created Date: May 6 2019 10:23AM