Steel as a Material for Bridges...

Steel as a Material for Bridges Steel is widely used around the globe for the construction of bridges of sizes ranging from from the very large to the very small. It is a versatile and effective material that provides efficient and sustainable solutions. Steel has long been recognized as the economic option for a range of bridges. It dominates the bridge constructions for long span bridges, railway bridges, footbridges, and medium span highway bridges. It is now increasingly the choice for shorter span highway structures as well. Early bridges were made of stone, wood and concrete. The arrival of the steam train in the mid-18th century ushered in a new era in bridge design. A stronger material was needed as bridges were required to carry heavier loads over longer spans. Iron was first used to bridge the ‘Tees’ river in England in 1741. By the 1880s, steel had become a material of choice. Amongst bridge materials steel has the highest and most favorable strength qualities, and it is therefore suitable for the most daring bridges with the longest spans. Normal building steel has compressive and tensile strengths of 370 N/sq mm, about ten times the compressive strength of a medium concrete and a hundred times its tensile strength. A special merit of steel is its ductility due to which it deforms considerably before it breaks, because it begins to yield above a certain stress level. Steel is an ideal material for bridges. It is an essential part of modern bridges because it is strong, can flex without fracturing and has a long life, even in the harshest conditions. It can be used to build bridges of any length because of its durability and ease of manufacture and maintenance. New grades of steel increase the...