Reinforced cementitious shear panels

A shear panel system, for resisting shear loads when fastened to metal framing, comprising:

• metal framing;
• a shear panel consisting of a panel-shaped continuous phase and first and second reinforcing members attached to the continuous phase;
• the shear panel-shaped continuous phase resulting from the curing of an aqueous mixture consisting essentially of water and,
• on a dry basis,
• 49 to 68 weight % a blend of reactive powders,
• 23 to 43 weight % uniformly distributed lightweight filler particles comprising uniformly distributed ceramic microspheres, and
• 5 to 20 weight % alkali-resistant glass fibers, wherein the glass fibers are monofilaments having a diameter of about 5 to 25 microns (micrometers) and a length of about 0.25 to 3 inches, and
• optional superplasticizer,
• the continuous phase being uniformly reinforced with the alkali-resistant glass fibers;
• the lightweight filler particles having a particle specific gravity of from 0.02 to 1.00 and an average particle size of about 10 to 500 microns (micrometers);
• wherein the blend of reactive powders comprises:
• 45 to 75 wt % calcium sulfate alpha hemihydrate,
• 20 to 40 wt % Portland cement,
• 0.2 to 3.5 wt % lime, and
• 5 to 25 wt % of an active pozzolan comprising silica fume;
• and
• the panel-shaped continuous phase having opposed first and second outer surfaces,
• first and second reinforcing members selected from the group consisting of plate and a mesh sheet attached to only the first outer surface of the continuous phase panel, the first reinforcing member and the second reinforcing member each respectively attached to the first surface along the entire length of two opposed edges of the panel covering the portion of the first surface opposite the second surface at the point(s) where the panel is attached to the metal framing with screws to form a first shear diaphragm, wherein the second surface of the panel opposed to the first surface has no reinforcing members;
• wherein the reinforcing members cover 5 to 90% of the first surface of the panel-shaped continuous phase, and
• wherein the shear panel fastened to the metal frame has a racking shear strength between 1.1 and 3.0 times the racking shear strength of a similar structural cement panel without reinforcing that is fastened to the same wall framing, and
• wherein the panel has a thickness of about ½ to 1½ inches (6.3 to 38.11 mm), and wherein the shear panel is fastened to the metal framing with metal screws with winged drillers, the winged drillers located above the point and below the threads of the screw and protruding laterally from the shaft of the screw to form a first shear diaphragm.

A non-combustible system for construction comprising:

• a shear diaphragm supported on a metal framing,
• the shear diaphragm comprising a shear panel for resisting shear loads when fastened to the metal framing,
• the shear panel consisting of a panel-shaped continuous phase and first and second reinforcing members;
• the shear panel shaped continuous phase resulting from the curing of an aqueous mixture consisting essentially of, on a dry basis,
• 49 to 68 weight % reactive powder,
• 23 to 43 weight % lightweight filler particles comprising uniformly distributed ceramic microspheres, and
• 5 to 20 weight % alkali-resistant glass fibers, wherein the glass fibers are monofilaments having a diameter of about 5 to 25 microns (micrometers) and a length of about 0.25 to 3 inches (6.3 to 76 mm), and
• optional superplasticizer,
• the continuous phase being uniformly reinforced with the glass fibers;
• the lightweight filler particles having a particle specific gravity of from 0.02 to 1.00 and an average particle size of about 10 to 500 microns (micrometers);
• wherein the reactive powders comprise
• 45 to 75 wt % calcium sulfate alpha hemihydrate,
• 20 to 40 wt % Portland cement,
• 0.2 to 3.5 wt % lime, and
• 5 to 25 wt % of an active pozzolan comprising silica fume;
• and
• the panel-shaped continuous phase having opposed first and second outer surfaces,
• first and second reinforcing members selected from the group consisting of plate and a mesh sheet attached to only the first outer surface of the continuous phase panel, the first reinforcing member and the second reinforcing member each respectively attached to the first surface along the entire length of two opposed edges of the panel, wherein the reinforcing member(s) cover the portion of the first surface opposite the second surface at the point(s) where the panel is attached to the metal framing, wherein the second surface of the panel opposed to the first surface has no reinforcing members;
• wherein the reinforcing members cover 5 to 90% of the first surface of the continuous phase panel,
• the metal framing comprising metal framing members,
• wherein the shear panel has a thickness of ¾ inch and has a racking strength ultimate load measured according to ASTM E72 racking from about 4600 to about 6000 lbs for an 8 foot by 8 foot wall assembly,
• wherein the shear panel is fastened to the metal frame with metal screws with winged drillers, the winged drillers located above the point and below the threads of the screw and protruding laterally from a shaft of the screw, to form the first shear diaphragm.