German approach to a holistic assessment of steel and composite bridges

Bridges are essential for the infrastructure network and cover a large investment volume. Compared to buildings bridges are especially long-living structures with a scheduled service-life of 100 years. Therefore, it is evident that special attention must be focused on the sustainability in bridge construction. In the German research project NaBrue on the holistic assessment of steel and composite bridges according to criteria of sustainability a concept is developed for the analysis of steel and composite bridges according to the three aspects of the environmental, economic and socio/cultural quality. Three different types of reference bridges and their variants are studied over the entire life cycle and specific characteristics of bridges pointed out regarding sustainability analyses. For individual members the degradation processes are identified. On this basis the life cycle can be described and anticipated as accurate as possible and required maintenance measurements planned. As a decisive feature a holistic database for bridges is being elaborated which will give support for decision making during design and at tender stage for an evaluation by criteria of sustainabil-ity.