Enhancement of the life-cycle performance of bridges using high-strength steel

Bridges have a significant role in society but are often massive structures requiring a high amount of materials, leading to high consumption of natural resources and high costs. In this respect, the use of high-strength steel (HSS) may represent a significant advantage as it enables to reduce the quantity of materials required for a structure to fulfil its function. Notwithstanding this potential benefit, the use of slender plates allowed by HSS makes I-girders more vulnerable to local bucking phenomena and fatigue issues. Hence, this article aims to discuss the potential advantages of HSS in bridge design, in terms of structural, environmental and economic performances. The discussion is based on a comparative analysis, in which a bridge made of steel grade S355 is compared with two alternative designs made of steel grade S690. The results of the analysis showed that although the use of HSS in bridges enables to save steel, thus providing some environmental advantages, in terms of costs the differences are negligible due to the higher requirements of HSS bridges.