Abstract: A lightweight cementitious panel formed from a core mix is disclosed. The lightweight cementitious panel comprises one or more lightweight aggregate filler in the amount of 0.5 to 5 weight percent of the core mix, one or more binders in the amount of 35 to 75 weight percent of the core mix, rheological admixture in the amount of about 0.5 to 5 weight percent of the core mix, surfactant in the amount of 0 to 0.1 weight percent of the core mix, one or more normal weight aggregate filler in the amount of 5 to 50 weight percent of the core mix, and water in the amount of 5 to 20 weight percent of the core mix.

Abstract: A process for the formation of highly durable cementitious board using lightweight aggregate is disclosed. The process comprises pouring a core mix onto a conveyor, wherein the core mix is comprised of one or more lightweight aggregate filler in the amount of 0.5 to 5 weight percent of the core mix, one or more binders in the amount of 35 to 75 weight percent of the core mix, rheological admixture in the amount of about 0.5 to 5 weight percent of the core mix, surfactant in the amount of 0 to 0.1 weight percent of the core mix, one or more normal weight aggregate filler in the amount of 5 to 50 weight percent of the core mix, and water in the amount of 5 to 20 weight percent of the core mix. The process further comprises passing the core mix under a screed roller to flatten the core mix to produce an extruding board with a desired thickness.

Abstract: A lightweight cementitious panel formed from a core mix is disclosed. The lightweight cementitious panel comprises one or more lightweight aggregate filler in the amount of 0.5 to 5 weight percent of the core mix, one or more binders in the amount of 35 to 75 weight percent of the core mix, rheological admixture in the amount of about 0.5 to 5 weight percent of the core mix, surfactant in the amount of 0 to 0.1 weight percent of the core mix, one or more normal weight aggregate filler in the amount of 5 to 50 weight percent of the core mix, and water in the amount of 5 to 20 weight percent of the core mix.

Abstract: A process for expanding small diameter polystyrene beads is disclosed. The process comprises applying a steam pressure of about three to seven pounds per square inch at a temperature of about two hundred twenty degrees Fahrenheit to two hundred forty degrees Fahrenheit to a plurality of expandable polystyrene beads until each of the plurality of expandable polystyrene beads has expanded to a diameter of about 0.030 inches to 0.125 inches, wherein each of the plurality of expandable polystyrene beads has an unexpanded diameter of about 0.015 inches to about 0.028 inches.

Abstract: A process for controlling the embedding depth of reinforcing mesh to a cementitious board is disclosed. The process comprises applying a pressure from a plate to a reinforcing mesh on a core mix moving downstream on a conveyor, wherein the plate vibrates at a rate that assists in embedding the reinforcing mesh at a depth within the core mix such that the reinforcing mesh is barely visible.

Abstract: A cementitious panel comprising a cementitious core which is fabric-reinforced at the surface thereof and whose longitudinal edges are reinforced by a network of fibers. A panel may be obtained wherein the surface edge reinforcement layers are relatively strong and hard such that a nail or screw may be driven through the edge of panel without pre-drilling and without breaking, even when nailed or screwed almost at the very limit of the edge of the panel. Such a panel may provide a long lasting substrate for humid or wet areas such as shower rooms and bath rooms.

Abstract: A composition for accelerating the setting reaction of an aqueous calcined gypsum slurry, and a method of making the same are disclosed. The composition includes a vibratory ball milled mixture of calcium sulfate dihydrate and a surfactant. The composition is prepared by subjecting the mixture to the high-frequency, low-impact grinding action of a vibratory ball mill. The resultant composition has a potency superior to that of conventional gypsum set accelerators.

Abstract: A method of continuously producing a cementitious composition such as joint compound includes pre-mixing at least two dry ingredients and pre-mixing at least two liquid ingredients. The ingredients are provided in a continuous mixing apparatus and at least substantially continuously blended.

Abstract: A cementitious panel comprising a cementitious core which is fabric-reinforced at the surface thereof and whose longitudinal edges are reinforced by a network of fibers. A panel may be obtained wherein the surface edge reinforcement layers are relatively strong and hard such that a nail or screw may be driven through the edge of panel without pre-drilling and without breaking, even when nailed or screwed almost at the very limit of the edge of the panel. Such a panel may provide a long lasting substrate for humid or wet areas such as shower rooms and bath rooms.

Abstract: This disclosure relates to a composite structural member comprising a body part and multiple rigid strips which are attached to and separated by the body part. The body part is formed by a core having substantially flat parallel sides and opposed edges, and the opposed edges are covered by the rigid strips. As an example, the core is made of gypsum, and the strips are made of sheet metal. The rigid strips enable screw fasteners to be secured to the structural member. The sides of the core are preferably covered by side sheets.

Abstract: A method of preparation and use of high-strength gypsum wallboard, as well as a core composition suitable for use therein, are disclosed. The core composition includes a slurry of calcium sulfate hemihydrate (stucco), water, and a strengthening agent. The strengthening agent includes an acrylic polymer composition having a glass transition temperature of about 15.degree. C. or greater, and preferably has good divalent ion stability. The method provides wallboard having increased core strength, paper-to-core bonding, and strength-to-weight ratio.

Abstract: A method of preparation of gypsum wallboard, as well as a core composition suitable for use therein, are disclosed. The core composition includes a slurry of calcium sulfate hemihydrate (stucco), water, and calcium aluminum lignosulfonate and/or aluminum lignosulfonate.

Abstract: Apparatus and method for producing gypsum board, comprising apparatus for coating a cover sheet with a relatively high density gypsum slurry, apparatus for forming edge borders on the sheet with relatively high density gypsum slurry, and apparatus for forming a core on the coating and between the edge borders, the core comprising a relatively low density gypsum. The apparatus for coating the sheet comprises a relatively soft pressure roll and a relatively hard coating roll, the two rolls being normally pressed together to form a nip between them and a sheet to be coated passing through the nip. The pressure roll is below the sheet and the coating roll, and the axis of the pressure roll is offset from the axis of the coating roll in upstream direction of the movement of the sheet. The pressure roll has a surface area which contacts and moves in the same direction as the sheet, and the coating roll has a surface area which contacts and moves in the opposite direction of the sheet.

Abstract: Cementitious binders include calcium sulfate beta-hemihydrate, a cement component comprising Portland cement, and either silica fume or rice-husk ash. The silica fume or rice-husk ash component is at least about 92 wt % amorphous silica and has an alumina content of about 0.6 wt % or less.

Abstract: A process for the production of a ready-mixed setting-type joint compound includes the use of calcium sulfate hemihydrate, water, and a set-retarding agent. The retarder includes a polymer composition including acrylic acid and acrylamide monomer units, for example a copolymer (or a mixture of copolymers) of acrylic acid and acrylamide or a blend of a homopolymer of acrylic acid and a homopolymer of acrylamide. The joint compound can be combined with an accelerator including a metallic salt. The joint compound of the invention can be formulated either as a lightweight joint compound or as a conventional weight joint compound. The joint compounds provide short setting times, reduced shrinkage, reduced preparation time, and beneficial application properties.

Abstract: A hollow shaft wall corner with each of two walls having alternating horizontal studs and horizontally extending core boards, with the horizontal studs of the two respective walls adjoined at the wall corner by small clips affixed to the horizontal studs. A method of construction of the wall further includes small clips adjoining the ends of core boards at the wall corner.

Abstract: This disclosure relates to a reinforced metal stud for use in a hollow wall. The wall includes sheet metal studs placed horizontally between adjacent, horizontally extending gypsum core boards, typically in the walls surrounding an elevator shaft and stairwells, and in area separation walls and the like. The metal studs include an inner flange, an outer flange and an adjoining web connecting the flanges, with a core board abutting each side of the web. Standard or special fire-retardant gypsum wallboards are attached by fasteners to the outer flanges of the metal studs. A hollow space is thus formed between the core boards and the wallboards, the outer flange and a portion of the web being within the hollow space. A reinforcement channel is provided for attachment to and strengthening of the stud. The web and the outer flange of the stud form a partially enclosed space, and the reinforcement channel nests in the enclosed space.

Abstract: This disclosure relates to a wall construction including an outer panel and an inner panel, the inner panel being formed by at least one wallboard. The outer and inner panels are substantially parallel and are spaced apart to form an interior space between them. Within the interior space and secured to the outer and inner panels are one or more framing members made of roll formed sheet metal. Each framing member comprises a web which extends between and is substantially perpendicular to the outer and inner panels. At an outer portion of the member is formed an outer flange which abuts and is secured to the outer panel. At an inner portion of the framing member is formed at least one tab which extends closely adjacent the inner panel and at least one cutout formed in the member. An adhesive secures the inner portion including the tab to the inner panel. The framing member may further include a clip which extends through the cutout and is attached to the panel.

Abstract: A hollow shaft wall with horizontal studs having angled stud webs forming a channel with the stud inner flanges. Core boards are held by one edge in the angled channel and the other edge held by suitable means on an adjacent horizontal stud. Wallboards are spaced from the core boards and are secured to flanges of the studs. Supports are provided at the ends of the core boards and the studs for holding the wall in a vertical orientation.

Abstract: This disclosure relates to a riser comprising an elongated web having one or more folds which form at least one ridge and slopes extending away from the ridge. When in use as a riser, the web is positioned on edge so that the edge surfaces of the ridges and the slopes engage the bottommost article being supported. The web preferably includes strengthening elements located at at least the ridges. A group of risers are nestable whereby they may be compactly stacked for storage and/or shipping. The edge surfaces have a surface area sufficient to avoid forming a substantial imprint in the article. The risers may be made of a recycled material, such as wood chips, plastic and gypsum, and the risers are reusable.