A Review of Developments in Steel: Implications for Long-Span Structures

Historically, iron in different forms has been known to exist for Architectural and Engineering applications from early periods of civilisation, but in the modern context, it would be best to review the growth of steel, during the last couple of centuries. This paper, first, traces briefly the developments in steel in terms of its various aspects, which are relevant to the design of structures. It is perhaps needless to remind ourselves that humans perpetually endeavour for a better quality of life. To meet the challenge thus created for providing additional and improved infrastructure, and, riding on a number of parallel (or nearly so) developments, the frontiers for Civil and Structural engineers and architects have moved to horizons not easy to imagine. One exciting thrust has been towards increased dimensions, in both height as well as span of structures, which have touched kilometres from tens of metres. One of the important factors responsible for the aforesaid developments is without reservation, the advancements in steel, and, products based upon it, for deployment in structures, besides the related aspects of fabrication, construction and maintenance. There are other factors too, such as, the growth of electronics which has led to enormously increased capabilities in computing. Also, there are the remarkable developments in instrumentation and robotics as tools in structural engineering. This has led to a paradigm shift in the scenario for structural analysis, design and drafting, construction and maintenance. In traversing the journey above, there are different aspects and features that have already become convention through practice and literature, and there is extensive awareness about them. On the other hand, there are issues and areas of comparatively new developments about which the awareness is rather limited. The emphasis in this text is largely on the latter. Since some of these issues can provide for extensive coverage, the attempt herein is to only bring out the salient features.