Basis of Design

This chapter introduces the objectives of steel structures and their main fields of application that include almost all types of works in the construction sector, listing the most important advantages for the basic material in terms of mechanical properties, the high prefabrication, the easiness of connection between elements, but also the “after construction” benefits, like recyclability, durability, or easiness for strengthening and repair. It makes reference to the Eurocodes and other specifications on which this book is based and more specifically to the parts and structure of Eurocode 3 that specifies the design of steel structures. It then gives the main types of actions and provides information on the determination of the most important ones for building structures like imposed loads, wind, snow, temperature or earthquake. The ultimate and serviceability limit states are defined and the combinations of actions, together with the relevant partial safety and combination factors. Finally, the main mechanical properties of steel and the structural steel grades are presented, with some basic information on the microstructure of steel and common steel making processes that help understand the source of attaining the specified mechanical, physical and chemical properties.