Bridges are fundamental links in all national, regional or local road networks. Any malfunctioning, lost of bearing strength or capacity to accommodate the increasing traffic intensity without restrictions, represent important costs in the economy of a region. Consequently, administrations needto devote the necessary resources for assuring the functionality and safety of bridge stocks. Depending on the level of development of the countries and their recent history, periods of intensive bridge construction have been concentrated in periods of, perhaps, one or more decades. In many European countries the period after World War II was critical in the construction of the road networks, bridges included. Other countries concentrate the development in their road infrastructure construction in parallel with economic expansion peaks. There are many examples of such intensive construction periods coinciding with the onset in the use of "new" structural materials, such as steel or concrete. The intensive use of concrete, for example, in the periods when their properties regarding durability were not suspect have resulted in cases where some bridges that have been inherited have an undesirable level of condition. The progress in the knowledge of the properties of concrete and steel, the improvement in construction quality control, the recommendations for reaching a durable structure from the design phase and the new tools for management of bridge stocks have brought about considerable changes. The work of the TC4.4 Committee during the last few years has been devoted to exploring the way different countries inthe world approach the question of bridge durability improvement in all phases of their life, i.e. design, construction and service, as well as comparing the criteria and procedure in different bridge administrations withimplemented Bridge Management Systems (BMS) to prioritize the resources for maintenance and repair. As historical bridges are in many countries an important subset of the bridge stock, the Committee decided to announce a call for contributions by engineers who are responsible for their maintenance, as they are special structures that sometimes do not fit in to standard management systems. The session TC4.4 organized by the Bridges and Related Structures Committee, will be organized in three parts and will include: presentation of the technical work of the Committee; invited speakers on historical bridges; and aspects for debate and future work. For the covering abstract see ITRD E139491.
Abstract