A reinforcing structure is described for use in supporting a floor at a junction thereof with a structural column. The structure has several generally elongate, preassembled frame structures, each frame structure are disposed in rows parallel to one another. The frame structures incorporate the main top and bottom reinforcement bars for the reinforced floor with integral shear connectors forming part of the frame structures and the shear connectors tying the top and bottom reinforcement together. Transverse internal reinforcing bars are disposed parallel to one another and connected across the top or bottom reinforcing bars of each frame structure to connect the preassembled frame structures into a cagework of spaced-apart, rigidly connected frame structures.