PRESTRESSED CONCRETE DOUBLE T-TYPE FLOOR SLAB WITH TENSION CHORD MEMBER

PURPOSE:To make a slab possible to be largely spanned in keeping its length constant intact by forming the slab into a double T-type sectional form while curving it upward, installing a tension chord member in space between fulcrums of the slab, and setting up a bundle member between the slab and the tension chord member. CONSTITUTION:A roof slab 1 is curved upward at the specified curvature, and made into a double T-type sectional form where a slab 1a and plural beams 1b parallelly installed are made up as one body. Prestressed concrete is taken into the roof slab 1 at need for reinforcement, so precast steel is inserted into concrete at a lower end of the beam 1b. A tension chord member 2 is installed in space between two fulcrums in the short side direction of the roof slab 1 at the lower side of this slab 1, and a central part of the tension chord member 2 is supported on the slab 1 by a bundle member 3. Therefore axial tension is mainly acting on the roof slab 1, a structurally disadvantageous bending stress is sharply reduced and, what is more, only tensile force acts on the tension chord member 2.