FLOOR DOUBLE SLAB, REINFORCING CAGE OF FLOOR DOUBLE SLAB, METHOD OF MANUFACTURING FLOOR DOUBLE SLAB, BED FOR MANUFACTURING REINFORCED CAGE AND METHOD OF ASSEMBLY OF REINFORCING CAGE Russian patent published in 1998 - IPC

FIELD: manufacture of prestressed reinforced concrete products used in construction of residential houses and production buildings including those in rural regions. SUBSTANCE: floor double slab is made in the form of upper and lower, similar or dissimilar, spaced in height half-slabs interconnected by truss-forming rod members of space reinforcing cage. According to the invention, first, one half-slab is cast by lowering into casing mold of space reinforcing cage with its side corresponding to upper or lower half-slab, placing of concrete, compacting and solidifying of placed concrete mix. Then produced half-slab together with transportable and tiltable prestressed cage is turned over and using the above procedure, the second half-slab is cast. Both surfaces of double slab are formed in molding by bottom plates of molds, i.e. as face surfaces. Space reinforcing cage of double slab is made on base of two transverse beams on which longitudinal reinforcing bars with bent ends are pulled over their bottom and top. Bent ends of upper and lower bars are welded to one another. Two transverse beams are braced from inside with temporary rod cross-bars installed on beam edges. Attached to stretched longitudinal reinforcing bars are shape-forming rod members made, for instance, in the form of flat zigzag bars. Bed table for manufacturing space reinforcing cage for bracing of its longitudinal bars and installing of temporary cross-bars has two horizontal supports for installation of cross-beams of reinforcing cage. Installed between them is one or several thermal jacks. Thermal jack consists of pipe with electric heater and removable spacers on pipe end. Assembling of the space reinforcing cage includes placing on bed plate of longitudinal bars of reinforcing cage, placing over bars, on two horizontal supports of table, of cross beams of reinforcing cage and their pressing to removable spacers at ends of thermal jacks, laying of upper longitudinal bars, joining by welding of bent ends of upper and lower bars, elevation of temperature of thermal jacks for calculated value approximately to 200 C to extend their length, introduction into increased space between edges of cross beams of temporary rod cross-bars of reinforcing cage, weakening of force mechanism for bracing of beams to transmit their stress to temporary rod-cross bars; attachment to prestressed reinforcing cage of shape-forming rod members and removal of reinforcing cage from bed. EFFECT: increased strength and rigidity of slab without increasing its weight, high-quality face surfaces on slab both sides and simplified manufacturing process of floor double slab. 12 cl, 10 dwg, 1 tbl