B-1.1 General Design Requirements
The general design requirements of Section 3 shall apply to this Annex.
B-1.2 Redistribution of Moments
Except where the simplified analysis using coefficients (see 22.5) is used, the moments over the supports for any assumed arrangement of loading, including the dead load moments may each be increased or decreased by not more than 15 percent, provided that these modified moments over the supports are used for the calculation of the corresponding moments in the spans.
B-1.3 Assumptions for Design of Members
In the methods based on elastic theory, the following assumptions shall be made:
- a) At any cross-section, plane sections before bending remain plain after bending.
- b) All tensile stresses are taken up by reinforcement and none by concrete, except as otherwise specifically permitted.
- c) The stress-strain relationship of steel and concrete, under working loads, is a straight line.
- d) The modular ratio has the value
where is permissible compressive stress due to bending in concrete in as specified in Table 21.
NOTE — The expression given for partially takes into account long-term effects such as creep. Therefore this is not the same as the modular ratio derived based on the value of given in 6.2.3.1.