Abstract: A concrete floor is constructed at least partially about a supporting hollow core tower. The hollow core tower, which preferably includes a rectangular section, closely conforms to the border of the floor at the elevational outside section where the floor is fastened. The floor at its edge, immediate the tower sides, is provided with beam defining folds preferably bent down at an angle in the range of 30.degree. to 60.degree. from the major plane of the floor. At least one beam at each tower and at least two non-linearly aligned beams at each floor are nested at the floor-tower interface, typically below the major supporting surface of the floor. The tower sidewall at the floor is transpierced and threaded to receive a tension support member angularly depending downwardly and outwardly from the inside of the tower to the outside of the tower. Likewise and in registry with apertures transpierced in the tower, the beam at the tower inside includes apertures extending angularly downward.

Abstract: An apparatus is disclosed for the improved support of floors extending peripherally outward from a central tower in a building construction. The central supporting tower typically of concrete and formed by conventional slip-form methods, has imbedded in it at the intended floor elevations a series of horizontally disposed receptacles, each receptacle opening outwardly toward the tower sidewalls. Floors are constructed, typically in sequence, around the towers at the base of the towers. Thereafter, solid steel pull bars are inserted interiorly of the receptacles for their full length by inserting at the open end of the receptacles from the exterior of the tower sidewalls. The floors are raised in sequence with the top floor being raised first. Each floor is raised an elevation slightly above the elevation of its correspondent supporting pull bars. When the floor is immediately above the pull bar, the pull bar is moved partially outwardly so as to underlie the floor in supporting relation.

Abstract: At least one hollow core tower (preferably of a rectangular construction) is constructed from a foundation to a preselected floor supporting height. The tower is preferably joined at the top and slotted vertically along at least one sidewall from the base of the tower to a partial height of the tower. Preferably the tower is slotted along opposed sidewalls to form opposed C-shaped sections confronting one another at the slots. After at least the lowest and ground adjacent portion of the tower is constructed, floors are built about the tower at or near ground level. The floors include a section extending into or across the tower at the slot or slots which preferably includes a cantilevered or spanning horizontal floor strengthening beam. Typically, the floors are constructed and stacked one on another at their ground level with the bottom floor built first and lowest, and the top floor or roof built last and highest at the top of the ground supported stack.