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.<\/p>\r\n","references":"[1] L. Beran, Reliability and load carrying capacity of existing steel railway\r\nbridge structures. PhD thesis. University of Pardubice, Pardubice, 2004.\r\n[2] B. Culek, Jr., The complex lifetime evaluation of the steel bridge with\r\nmember deck. 3rd Int. Conf. \"Reliability, Safety and Diagnostics of\r\nTransport Structures and Means\", Pardubice, 25-26. 9. 2008,\r\nUniversity of Pardubice, 2008, pp. 33-40.\r\n[3] B. Culek, Jr., et al., Determination of influence of temperature on fatigue\r\ndurability of steel bridges with member decks. Tech. report. Annex to (8), University of Pardubice, 2007.\r\n[4] B. Culek, Jr., B. Culek, Probabilistic assessment of the lifetime of the\r\nrailway steel bridge across river Labe. 24th Danubia-Adria Symposium\r\non Developments in Experimental Mechanics. Sibiu, 19-22 September\r\n2007. University Lucian Blaga, Sibiu, 2007, pp. 59 - 60.\r\n[5] J. Mare\u253c\u00ed, Diagnostics of atmospheric corrosion of concrete\r\nconstructions in transport strucures. PhD thesis, University of\r\nPardubice, Pardubice, 2009.\r\n[6] J. Mare\u253c\u00ed, J. Men\u2500\u00ec\u251c\u00a1k, Experimental assessment of concrete deterioration\r\nin existing bridges. 3rd Int. Conf. \"Reliability, Safety and Diagnostics of\r\nTransport Structures and Means\". Pardubice, 25-26. 9. 2008,\r\nUniversity of Pardubice, 2008, pp. 197-201.\r\n[7] J. Men\u2500\u00ec\u251c\u00a1k, J. Mare\u253c\u00ed, Characterisation and prediction of concrete\r\ndeterioration in existing structures. Int. Conf. \u00d4\u00c7\u00d7Life cycle assessment,\r\noptimisation, behaviour and properties of concrete and concrete\r\nstructures\", Brno, 12-14. 11.2008, FAST VUT Brno, pp. 218-223.\r\n[8] J. Men\u2500\u00ec\u251c\u00a1k, et al., Determination of load carrying capacity and fatigue\r\ndurability of bridge constructions. Tech. reports (grant project GA\u2500\u00eeR\r\n103\/05\/2066), University of Pardubice, 2005-2007.\r\n[9] H. Gr\u00f6ber, S. Erk, U. Grigull, Die Grundgesetze der\r\nW\u251c\u00f1rme\u251c\u255dbertragung. Springer Verlag, Berlin - G\u00f6ttingen - Heidelberg,\r\n1955.","publisher":"World Academy of Science, Engineering and Technology","index":"Open Science Index 38, 2010"}