Lifetime extension of existing steel bridges

Abstract

Prolonging the life of existing steel trusses all over the world is a incoming necessity for all managing authorities wherever these structures have reached a particular state of use. The unsatisfactory behavior of these structures under the current type and increasing number of loads make clearer that innovative solutions are needed. For this purpose, the realization of composite decks is needed, in order to redistribute the common actual load onto a structure conceived with historical codes, characterized by lower design live loads. The possibilities of retrofitting bridges with this solution studied in a recent research program are presented and compared in this study. Increasing traffic density and vehicle weight have been increasing in recent decades. Many existing truss bridges, all over the world, were not designed for the high service loads and the increased number of load cycles that they are exposed to today