Structural Steel in Construction: Fundamentals

About this course.

Steel is used structurally because it offers a rare combination of high strength in both tension and compression, predictable and consistent properties, and the ability to be shaped into efficient members and joined into complete structures. Kilogram for kilogram it is very strong, so it can span long distances and carry heavy loads with relatively slender members, and because it is manufactured to controlled specifications its behaviour is well understood and reliable. It is also fast to erect, since much of the work is completed off site in a fabrication shop and then bolted or welded together on site. Steel suits long spans, heavy loads, tall or repetitive framing, and situations where speed, slenderness, precision or future adaptability matter.

The properties that make steel attractive begin with its strength-to-weight ratio. Steel is strong for its weight, which means structural members can be comparatively light and slender while still carrying substantial loads and spanning significant distances. This efficiency reduces the size and self-weight of the structure, which in turn can reduce the loads carried down to the footings and the size of the foundations. Long clear spans — the open interiors of warehouses, sports halls, factories and showrooms — are difficult to achieve economically in many other materials but are a natural fit for steel, which is one reason steel dominates industrial and large-span construction.