...J. R. Eyre, BA, BSc, PhD, RIBA In certain circumstances, the elimination of steel bar reinforcement from concrete slab construction is made possible by the presence of compressive membrane action. Design practice cannot conveniently take advantage of this, because rigorous strength calculations...

... are developed in the cross-section so that the section may be analysed as a series of ultimate, i.e. ‘rectangular’, stress blocks. The concrete slab is assumed to be fully stressed over its effective breadth. Transverse reinforcement across the section is ignored in the moment capacity calculations...