Patent ID: 8122679
Filing Date: 2012-02-28
Classification: B32B,C04B,E04B,Y02W,Y10T

Abstract:
1. A method of providing fire resistance to a building structure comprising: making an area separation wall comprising assembling a system as a firewall for the building structure by forming a shear diaphragm supported on light gauge cold formed metal framing, the system comprising: a first shear diaphragm comprising a first plurality of reinforced, lightweight, dimensionally stable cementitious panels, each of the panels of the first plurality having an opposed first side and second side; and a first metal framing comprising the metal cold formed metal framing elements, a second diaphragm comprising a second plurality of panels selected from the group consisting of Type X fire rated gypsum wallboard panels and reinforced, lightweight, dimensionally stable cementitious panels, each of the panels of the second plurality having an opposed first side and second side; a second framing, the second framing comprising studs between the first diaphragm and the second diaphragm; and break away fasteners; by the steps of: placing the first side of the structural cementitious panels of the first shear diaphragm on the metal framing elements of the first metal framing; and attaching the structural cementitious panels of the first shear diaphragm on the first metal framing, the first side of the cementitious panels of the first diaphragm supported on the first framing, wherein the cementitious panels of the first shear diaphragm are attached on the first metal framing by 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; attaching each of a plurality of the break away fasteners to both the second side of the cementitious panels of the first diaphragm and to a said stud of the second frame; wherein the plurality of second panels of the second diaphragm each have the opposed first wall and second wall, the first wall of the panels of the second diaphragm being opposed to the second wall of panels of the first diaphragm, and attaching the panels of the second diaphragm to the studs of the second framing such that the first wall of the panels of the second diaphragm opposes the studs; the first diaphragm being between the first metal framing and the second diaphragm, the breakaway fasteners being between the first diaphragm and the second diaphragm, wherein the cementitious panel of the first and second diaphragm have a thickness of about ⅜ to 1½ inches; the cementitious panels of the first and second diaphragms having a density of 65 to 90 pounds per cubic foot and capable of resisting shear loads when fastened to the framing and comprising a continuous phase resulting from the curing of an aqueous mixture comprising, on a dry basis, 49 to 68 weight % reactive powder, 23 to 36.1 weight % lightweight filler, comprising ceramic microspheres, and 5 to 20 weight % alkali-resistant glass fibers, the continuous phase being uniformly reinforced with the 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), 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 water and optional superplasticizer and, on a dry basis, 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, wherein, the system is the fire wall and a shear wall for carrying shear load and axial load when exposed to fire.