General considerations on bridge durability

This article surveys some general aspects of bridge durability. The life expectancy of many bridges varies considerably, ranging from about 40 years upwards. However, economic considerations require that it is even higher, at least of the order of a century. This is generally considered to be feasible for modern structures. Figures are provided of the rate of bridge replacement in 10 European countries and in the USA. The number of bridges being replaced per year in different European countries range from 0.1% to 2%. In the USA, the percentage is about 0.2%. These percentages are lower where there is a higher number of new bridges. Data are provided about the age of bridges in the various countries, the materials used to build them, and some of the more important defects which have occurred. There needs to be a correct balance between bridge cost and bridge quality both at the design and at the construction stages. The problem of durability is as important for small bridges as for large bridges, because small bridges are much more numerous. They need to have a simple design and construction method. The recent efforts supporting bridge inspection and maintenance in many countries need to be developed further. Prevention of deterioration is much more efficient and much less expensive than later repairs. For the covering abstract of the conference see IRRD 858334. The French title of this paper is:- Considerations generales sur la durabilite des ponts. The German title of this paper is:- Allgemeine Betrachtung ueber die Dauerhaftigkeit von Bruecken.