Methods for Better Assessment of Fatigue and Deterioration in Bridges and Other Steel or Concrete Constructions

Large metal and concrete structures suffer by various kinds of deterioration, and accurate prediction of the remaining life is important. This paper informs about two methods for its assessment. One method, suitable for steel bridges and other constructions exposed to fatigue, monitors the loads and damage accumulation using information systems for the operation and the finite element model of the construction. In addition to the operation load, the dead weight of the construction and thermal stresses can be included into the model. The second method is suitable for concrete bridges and other structures, which suffer by carbonatation and other degradation processes, driven by diffusion. The diffusion constant, important for the prediction of future development, can be determined from the depth-profile of pH, obtained by pH measurement at various depths. Comparison with measurements on real objects illustrates the suitability of both methods.





References:
[1] L. Beran, Reliability and load carrying capacity of existing steel railway
bridge structures. PhD thesis. University of Pardubice, Pardubice, 2004.
[2] B. Culek, Jr., The complex lifetime evaluation of the steel bridge with
member deck. 3rd Int. Conf. "Reliability, Safety and Diagnostics of
Transport Structures and Means", Pardubice, 25-26. 9. 2008,
University of Pardubice, 2008, pp. 33-40.
[3] B. Culek, Jr., et al., Determination of influence of temperature on fatigue
durability of steel bridges with member decks. Tech. report. Annex to (8), University of Pardubice, 2007.
[4] B. Culek, Jr., B. Culek, Probabilistic assessment of the lifetime of the
railway steel bridge across river Labe. 24th Danubia-Adria Symposium
on Developments in Experimental Mechanics. Sibiu, 19-22 September
2007. University Lucian Blaga, Sibiu, 2007, pp. 59 - 60.
[5] J. Mareš, Diagnostics of atmospheric corrosion of concrete
constructions in transport strucures. PhD thesis, University of
Pardubice, Pardubice, 2009.
[6] J. Mareš, J. Menčík, Experimental assessment of concrete deterioration
in existing bridges. 3rd Int. Conf. "Reliability, Safety and Diagnostics of
Transport Structures and Means". Pardubice, 25-26. 9. 2008,
University of Pardubice, 2008, pp. 197-201.
[7] J. Menčík, J. Mareš, Characterisation and prediction of concrete
deterioration in existing structures. Int. Conf. ÔÇ×Life cycle assessment,
optimisation, behaviour and properties of concrete and concrete
structures", Brno, 12-14. 11.2008, FAST VUT Brno, pp. 218-223.
[8] J. Menčík, et al., Determination of load carrying capacity and fatigue
durability of bridge constructions. Tech. reports (grant project GA─îR
103/05/2066), University of Pardubice, 2005-2007.
[9] H. Gröber, S. Erk, U. Grigull, Die Grundgesetze der
W├ñrme├╝bertragung. Springer Verlag, Berlin - Göttingen - Heidelberg,
1955.