ABSTRACT
The same notation and sign convention are used as in YLT. As regards the term "restraint", the follow ing remarks should be noted. It is necessary to differentiate between geometric and static restraint. With geometric restraint, movements of the slab are completely prevented at the restraint and the re straining moment is statically indeterminate. With static restraint, the restraining moment is given and is equal to the ultimate moment in the section of restraint. The movement of the section of restraint is geometrically indeterminate. The older term, partial restraint, corresponds more closely to static
restraint, although it does not cover this completely, as partial restraint can only give restraining moments that are smaller than those corresponding to geometric restraint, whereas static restraint may well result in greater restraining moments. In the following, restraint should be taken to mean static restraint, unless otherwise stated. The true value of the ultimate moment m corresponds to the failure load. However, in practical calculations, only a fraction of this-the working load-is used, and the corresponding value of m should then really have another name, for example, yield-line moment, which, is the same fraction of the true ultimate moment. However, this distinction is not made in the following, the term ultimate moment or, simply, the moment m being used instead of yield-line moment, so the possi bility of mistakes is precluded. Decimal classification is used throughout, both for chapters and sub-sections and for the corresponding formulae and figures.
