Disclosed is a composite gypsum board comprising a set gypsum core disposed between face (e.g., Manila) and back (e.g., Newsline) cover sheets. The set gypsum core is formed from a core slurry comprising stucco, water, and optional additives, such as foaming agent, migrating starch, accelerator, retarder, dispersant, etc. A dense layer formed from a dense layer slurry comprising stucco, water, fiber (e.g., paper fiber), and optionally, strength-enhancing starch, is disposed between the core and the face paper. The dense layer slurry contains a greater concentration of fiber, and optionally, strength-enhancing starch, than the core slurry, but the concentration of one or more other additives (e.g., accelerator, retarder, dispersant, or combinations thereof) is lower or the same in the dense slurry as compared with the core slurry. Also disclosed is a method of making board using one board mixer. In embodiments, paper fiber is added to water to form a suspension. The suspension is introduced, while in a non-laminar state, into the dense slurry. Further disclosed is apparatus, such as an extractor and an additive injection system, which can be a part of a cementitious slurry mixing and dispensing assembly.

To provide a molded body which has high strength, high ductility, and excellent dimensional stability while maintaining incombustibility and fire resistance. A molded body formed from a curable composition containing (A) at least one aluminosilicate source, (B) an alkali metal hydroxide, (C) a calcium ion source, and (D) an alkali resistant fiber, wherein the aluminosilicate source (A) has an SiO.sub.2 content of 50% by mass or more based on a total mass of the aluminosilicate source (A), an amorphous ratio of 50% by mass or higher, and an average particle diameter of 50 μm or smaller, and comprises an aluminosilicate source having an average particle diameter of 10 μm or smaller in an amount of 30% by mass or more based on the total mass of the aluminosilicate source (A).

The invention relates to a panel and a method for producing a panel. The panel is in particular a floor, wall or ceiling panel, and comprises at least one core layer, the core layer comprising an upper core surface and a lower core surface and at least one pair of opposite side edges; wherein the core layer comprises magnesium oxide cement and fibres dispersed in said magnesium oxide cement.

An object is to provide an inorganic board and a method for manufacturing the same that are suited to achieving high waterproofness.

A manufacturing method of the present invention includes first to sixth steps. The first step involves depositing a raw material on a receiving plate B1 to form a first layer L1. The second step involves pressing a first portion Ma and a second portion Mb of a raw material mat M including the first layer L1 toward the receiving plate B1 to compress the first portion Ma and the second portion Mb. The first portion Ma and the second portion Mb are one end portion and the other end portion, respectively, of the raw material mat M in a first direction D1. The third step involves depositing a raw material on the first layer L1 to form a second layer L2. The fourth step involves planarizing an exposed surface of the second layer L2. The fifth step involves curing the raw material mat M pressed between the receiving plate B1 and a pressing plate B2 to form a cured plate M′ from raw material mat M. The sixth step involves processing the first portion Ma and the second portion Mb into a first back-side joint part P1 and a first front-side joint part P2, respectively. An inorganic board X1 according to the present invention includes the first back-side joint part P1 and the first front-side joint part P2 that are high-density parts.

[Object] To provide a building material having excellent durability. [Solution] A building material has a convex part formed on a surface thereof, the convex part including a first lateral surface part and a second lateral surface part corresponding to the first lateral surface part. The building material is formed from a mixture containing a hydraulic material, an admixture, and a plant-based reinforcing material, and the plant-based reinforcing material at least in the convex part is distributed in the mixture with the hydraulic material and the admixture attached to the plant-based reinforcing material. A distribution of the plant-based reinforcing material in the first lateral surface part and a distribution of the plant-based reinforcing material in the second lateral surface part are substantially the same. Desirably, the convex part includes a first edge part that is an edge part of the first lateral surface part and a second edge part that is an edge part of the second lateral surface part and that corresponds to the first edge part, and a distribution of holes formed in the first edge part and a distribution of holes formed in the second edge part are substantially the same.

The present invention relates to fiber cement products comprising a first layer, which first layer is covered by at least one second layer, characterized in that said first layer is the top layer and the first layer material has a density of between about 0.4 and about 0.9 g/cm.sup.3 inclusive, and at least comprises cement and between 1 wt % and 70 wt % (relative to the total dry weight of said first layer material) of a lightweight filler, and said at least one second layer is the bottom layer and covers only one of the main surfaces of the first layer, thereby forming a bi-layered fiber cement product, wherein the second layer material has a density of between about 0.9 and about 1.4 g/cm.sup.3 inclusive, and at least comprises fibers and cement.

[Object] To provide a building material having excellent durability.

[Solution] A building material has a convex part formed on a surface thereof, the convex part including a first lateral surface part and a second lateral surface part corresponding to the first lateral surface part. The building material is formed from a mixture containing a hydraulic material, an admixture, and a plant-based reinforcing material, and the plant-based reinforcing material at least in the convex part is distributed in the mixture with the hydraulic material and the admixture attached to the plant-based reinforcing material. A distribution of the plant-based reinforcing material in the first lateral surface part and a distribution of the plant-based reinforcing material in the second lateral surface part are substantially the same. Desirably, the convex part includes a first edge part that is an edge part of the first lateral surface part and a second edge part that is an edge part of the second lateral surface part and that corresponds to the first edge part, and a distribution of holes formed in the first edge part and a distribution of holes formed in the second edge part are substantially the same.

The present invention relates to fiber cement products comprising an inner core material, which inner core material is covered by at least one outer surface layer, characterized in that: —said inner core material has a density of between about 0.4 and about 0.9 g/cm.sup.3 inclusive, and at least comprises cement and between 1 wt % and 70 wt % (with respect to the total dry weight of said inner core material) of a lightweight filler, and—said at least one outer surface layer has a density of between about 0.9 and about 1.4 g/cm.sup.3 inclusive, and at least comprises fibers and cement.

The invention relates to a panel and a method for producing a panel. The panel is in particular a floor, wall or ceiling panel, and comprises at least one core layer, the core layer comprising an upper core surface and a lower core surface and at least one pair of opposite side edges; wherein the core layer comprises magnesium oxide cement and fibres dispersed in said magnesium oxide cement.

An additive injection system can be a part of a cementitious slurry mixing and dispensing assembly. The additive injection system can be used to inject an additive into an auxiliary slurry discharge conduit carrying a secondary flow of cementitious slurry produced in the assembly such that the secondary slurry stream is different from a main slurry stream discharged from a main slurry discharge conduit.