Consider a steel column section ISHB 250 @ 536.6 N/m carries a factored axial load of 250 kN. A square base plate of size 55 cm × 55 cm is provided to transfer the axial load to concrete pedestal of grade M20. If the length of the larger and smaller projection of the slab base beyond the rectangle circumscribing the column is 70 mm and 65 mm respectively, the minimum thickness of rectangular slab bases supporting columns under axial compression required will be ________
(Assume bearing strength of concrete to be 0.45 fck and yield strength of steel plate to be Fe 250, Material factor of safety (γmo) for steel to be 1.1)1
6 mm
2
7 mm
3
8 mm
4
9 mm