2.2Structural Steel

2.2.3.1

Steel that is not supported by mill test result may be used only in unimportant members and details, where their properties such as ductility and weldability would not affect the performance requirements of the members and the structure as a whole.

However, such steels may be used in structural system after confirming their quality by carrying out appropriate tests in accordance with the method specified in IS 1608.

2.2.4.1

Physical properties of structural stee irrespective of its grade may be taken as:

• a) Unit mass of steel, $\rho=7850 \mathrm{~kg} / \mathrm{m}^{3}$
• b) Modulus of elasticity, $E=2.0 \times 10^{5} \mathrm{~N} / \mathrm{mm}^{2}$ (MPa)
• c) Poisson ratio, $\mu=0.3$
• d) Modulus of rigidity, $G=0.769 \times 10^{5} \mathrm{~N} / \mathrm{mm}^{2}$ (MPa)
• e) Co-efficient of thermal expansion $\alpha_{\mathrm{i}}=12 \times$ $10^{-6} /{ }^{\circ} \mathrm{C}$

2.2.4.2 Mechanical properties of structural steel

The principal mechanical properties of the structural steel important in design are the yield stress, $f_{y}$; the tensile or ultimate stress, $f_{u}$; the maximum percent elongation on a standard gauge length and notch toughness. Except for notch toughness, the other properties are determined by conducting tensile tests on samples cut from the plates, sections, etc, in accordance with IS 1608. Commonly used properties for the common steel products of different specifications are summarized in Table 1.