Question

The bending moment coefficients for continuous RC slabs in IS: 456-1978 code is based on

• A. Pigeaud's method
• B. Marcus's method
• C. Yield-line theory
• D. Westergaard's mathematical analysis

Answer 1

The correct option is B Marcus's method

IS 456 : 1978 has adopted moment coefficients derived by Rankine-Grashoff for the analysis of simply supported rectangular slab without any provision for torsion. For continuous RC slabs Marcus' method is the basis.
IS 456 : 2000 has adopted moment coefficients derived by Rankine-Grashoff for the analysis of simply supported rectangular slab without any provision for torsion as in Table 27.
However, for continuous RC slab, coefficient of
Table 26 is based on yield line theory.