Precast building construction

Claim 1

Apparatus according to claim 1, each said assembly comprising a lifting bracket having said slab-engaging means, and a lifting jack comprising said jacking means supporting said bracket.

Claim 4

A method of constructing a multistory building, comprising: preforming on a ground-supported base a stack of horizontal slabs one upon the other and of a length and width to cover a substantial building area; providing in each of said slabs a plurality of lifting column openings vertically aligned in the stack; erecting in said openings ground-supported lifting columns; mounting lifting apparatus on said columns; operating said apparatus to lift said stack of slabs along said columns until the lowest slab in the stack has reached an elevation above said base higher than its intended erected position; supporting said lowest slab at said higher elevation on said columns and detaching it from the stack and said lifting apparatus; further operating said lifting apparatus on said columns to lift the remainder of the stack from said column-supported lowest slab while it is held at said higher elevation; while said remainder of the stack is undergoing further lifting by said apparatus, erecting building substructure independent of said columns under said lowest slab to provide ultimate support for it; lowering said lowest slab onto said substructure for full support by said substructure and releasing such slab from said columns; repeating the foregoing procedure with each succeeding lowest slab; and finally removing said apparatus and columns.

Claim 7

A method of constructing a multistory building, comprising: preforming on a ground-supported base a stack of horizontal slabs one upon the other and of a length and width to cover a substantial building area; providing in each of said slabs a plurality of column openings vertically aligned in the stack; erecting ground-supported columns to project upwardly through said openings to a height at least near the elevation to which the lowest slab in the stack is to be raised; mounting lifting apparatus on said columns at a height which is sufficient to enable lifting the entire stack to adjacent said elevation; connecting lifting rods to the slabs in the stack and attaching the lifting rods operatively to said lifting apparatus; actuating the lifting apparatus to raise the rods and thereby lift the stack to adjacent said elevation but with a clearance space between said lifting apparatus and said stack; mounting on the colUmns respective holding carriages within said space and connecting said carriages to said rods in load-supporting holding relation to thereby support the stack from said carriages; disconnecting said lifting apparatus from said rods and relocating the apparatus on the columns at a second height near the elevation to which the next succeeding lowest slab is to be raised; then reconnecting the lifting apparatus to said rods for operation to continue lifting of the stack and disconnecting said holding carriages; continuing lifting of the stack until the lowest slab has reached said elevation therefor; supporting said lowest slab on said columns; releasing said lowest slab from the stack; and operating said apparatus to raise the stack from said lowest slab to adjacent the elevation to which the next succeeding lowest slab is to be raised.

Claim 17

A method of constructing buildings comprising: forming a stack of reinforced separate concrete building floor and roof slabs successively one on top of the other; during the forming of each slab forming respective column receiving holes therein aligned with the sImilar holes in the other slabs; adjacent to each of said holes removably mounting in the slabs a plurality of vertical slab-connecting lifting rod extension elements having their upper ends above the topmost slab for coupling thereto of lifting rods of lifting apparatus to be carried by columns mounted through said aligned holes; removably securing lifting plates on said lifting rod extension elements under each of the slabs; whereby all of the slabs can be lifted in unison and then each lower slab can be released successively from the bottom of the lifted stack; and supporting for each slab to be formed a hole core and lifting plate socket-forming spider as a thickness gauge on said extension elements above the surface upon which the slab is to be formed.

Claim 19

A method of constructing a multistory building, comprising: preforming on a ground-supported base a stack of horizontal slabs one upon the other and of a length and width to cover a substantial building area; providing in each of said slabs a plurality of lifting column openings vertically aligned in the stack; erecting in said openings ground-supported lifting columns; mounting lifting apparatus on said columns; operating said apparatus to lift said stack of slabs along said columns until the lowest slab in the stack has reached an elevation above said base higher than its intended erected position; supporting said lowest slab at said higher elevation on said columns and detaching it from the stack and said lifting apparatus; further operating said lifting apparatus on said columns to lift the remainder of the stack from said column-supported lowest slab; preforming substructure in a plurality of load-supporting column units having opposite end upper and lower respective bearing faces; erecting said column units as building substructure independent of said columns and locating said units at desirable locations and supporting the units on their lower bearing faces whereby to provide ultimate support under said lowest slab, placing grout retaining generally ring-shaped gaskets onto the upper bearing faces of the units to surround the major areas of such faces; placing load-bearing shims which are slightly thinner than said gaskets between said upper faces and said lowest slab whereby to prevent collapse of said gaskets from the weight of the slab but permitting sealing compression of the gaskets by said weight; lowering said lowest slab onto the gaskets and thereby enclosing grout spaces within said gaskets; filling said spaces with grout to assure stable and efficient full support load distribution from the lowest slab onto the units; releasing said lowest slab from said columns; repeating the foregoing procedure with each succeeding lowest slab; and finally removing said apparatus and columns. 21 In a method of constructing a building wherein a preformed slab is lifted along columns mounted in openings in the slab; mounting said columns on baseplates; mounting said baseplates on grout-retaining gaskets; holding said columns in vertical orientation with the baseplates normal to the vertical axes of the respective columns; filling grout under the baseplates into areas enclosed by said gaskets; setting the grout to assure balanced vertical load distribution through said columns; said gaskets comprising elastomeric material; floatingly supporting said baseplates and effecting said vertical orientation aided by said floating mounting of the baseplates; said baseplates having respective holes therethrough to the space within the gaskets; and filling the grout through said holes.