Question

Identify and briefly discuss any two properties of steel structure. Briefly discuss two properties that you have selected for part a) in the context of a structural steel design.

Answer 1

Properties of steel structure:

Tensile property = In construction the most common variety of steel used is mild steel. This property of steel can be explained from the stress - strain curve. Within the proportionality limit, and by Hooke's Law, the deformation in steel is not permanent once the load is removed. The elastic modulus is around 200 GPa.But after a certain point the plastic deformation starts. This is called the yield point and the strain is 0.002. More the % of carbon the more is its strength but the more is it brittle. When steel is used in structures with dynamic loads then while design high rate of strain is considered. Concrete is weak in tension, so by adding steel and making RCC we are basically eliminating the shortfalls in tension.The tensile strength for S275 steel is 410 N/mm2

Hardness = When inelastic deformation occurs, then the resistivity capacity of the structure to withstand this, is known as hardness. It is also used in the evaluation of tensile strength.

Durability = is a measure of the corrosion prevention property of steel.Prevention is done by means of painting and galvanisation . The amount of coating to be provided is also dependent on the amount of damage, design life, exposure, etc.It is an electrochemical process.