Sineco develops maintenance programs on bridge structures as an integrated method based on the historical inspection results database and the bridge management system tools provided by the software Pontis. It is generally possible to create probabilistic deterioration models very customized and reliable for different bridge networks using the amount of historical inspection data. Nevertheless, in some particular cases, despite of a great amount of available data, it is not possible to draw up a deterioration model for a medium-long time forecast, as described in this paper for a network of forty years old bridges. To overcome this problem, a theoretical method has developed to draw up deterioration curves using available concrete carbonation tests on structures of the considered network. The described method, that can be repeated for other similar case, provide a realistic deterioration model to simulate future deterioration and to obtain a maintenance program in a medium-long term scenario
