The presence of the slab on the compression side of a T-beam permits the use of a large amount of tensile, steel in the rib. In continuous spans, however, the reverse moment at the support is usually comparable in magnitude with the span moment, and so also calls for a considerable amount of tensile steel; but as the slab is now not on the compression side the rib concrete often requires the assistance of compression reinforcement (Fig. 1).
F.H. Blake