The present invention generally relates to cementitious material that is a precursor of a magnesium oxychloride cement (MOC) and comprises treated carbon fibers comprising a dispersing agent at least partially coating the carbon fibers and processes for the preparation thereof. The present invention is also related to cementitious material that is a precursor of a magnesium oxychloride cement (MOC) and comprises siliconate and processes for the preparation thereof. The present invention further relates to cementitious material (e.g., pourable, extrudable, moldable and formable cementitious material) and cementitious construction material (e.g., boards, structural laminates, etc.) formed from curing the cementitious material.

A refractory composition including refractory aggregate, one or more matrix components, and silicate-coated set accelerator particles. The silicate-coated set accelerator particles can include one more of silicate-coated calcium hydroxide, magnesium hydroxide, calcium chloride, calcium carbonate, magnesium carbonate and calcium sulfate. Suitable silicate coatings include sodium silicate, potassium silicate, lithium silicate and mixtures thereof. A method of recovering an aged refractory composition, a settable composition and a method of manufacturing silicate-coated calcium hydroxide particles are also provided.

The present invention relates to relates to methods of making concrete from cement and, in particular, methods of making usable standard concrete from aged or otherwise substandard cement.

The present invention relates to relates to methods of making concrete from cement and, in particular, methods of making usable standard concrete from aged or otherwise substandard cement.

The invention concerns a method for producing gypsum boards, wherein a liquefier for the gypsum slurry is foamed with gas to provide a foam having a water content of less than 85 wt.-%, then incorporated into a gypsum/water mixture and the mixture thus obtained is applied on a two dimensional substrate. The incorporation of the liquefier in foamed form allows for a significant reduction of the amount of liquefier required to provide a desired flowability of the gypsum/water mixture, thus allowing the production of gypsum boards with similar characteristics with less liquefier. The invention further concerns gypsum board prepared using this process, apparatuses for producing gypsum boards using this process and the use of a corresponding liquefier foam to minimize the amount of liquefier required to establish a desired flowability of a gypsum/water mixture.

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.

A method for the application of hydrous mineral binder compositions which contain fibres. An aqueous accelerator is mixed with the aqueous binder composition in a mixer shortly before the application. The method is very robust and makes it possible to quickly produce even large moulded bodies having a uniform surface and very good strength development properties.

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 present invention discloses an artificial stone slab, wherein the raw materials are mixed, pressed, and solidified, and the raw material comprises a main material and an auxiliary material. The main material, according to the total weight ratio of raw materials, comprises from about 20% to about 85% of particles containing hydroxide or metal oxide, from about 0% to about 50% of natural quartz, and from about 5% to about 25% of resin. The auxiliary material comprises a coupling agent and a curing agent, wherein the weight ratio of the coupling agent to the resin is from about 0.6:100 to about 2:100, and the weight ratio of the curing agent to the resin is from about 0.8:100 to about 1.2:100. The present invention also provides methods for manufacturing the aforesaid artificial stone slab. The present invention replaces natural quartz particles with particles containing hydroxide or metal oxide and ensures that the performance of the slab is up to standard, that the quality is more stable and easier to control, the decorative results are better, and finally, the mining of natural quartz is reduced by 10 times, achieving the objectives of greater environmental protection and lower costs. The resulting slab provides stable performance with good decorative results and thus saves resources and is conducive to environmental protection.

A synchronous single-liquid grouting slurry, its technology and application for large diameter shield engineering under water-rich, high-pressure and weak soil strata conditions, comprising raw materials: 1050-1200 parts of gold tailing, 420-480 parts of silicate cement clinker, 220-240 parts of fly ash, 45-120 parts of waste clay brick, 65-95 parts of slag, 25-45 parts of limestone tailing, 70-80 parts of steel slag, 30-45 parts of silica fume, 15-22 parts of desulfurized gypsum, and 9-15 parts of quick-setting and early-strength composite additive. The invention controls the d.sub.50, d.sub.85 and d.sub.95 of the material particles as 35-40, 42-48 and 50-55 μm, respectively. Gold tailing with the particle size of 120-600 μm being used as the fine aggregate, their volume fractions are 40-60%. The slurry production technique, comprising crushing-sieving-superfine ball milling-homogenization-particle size classification-variable speed mixing being developed. The shield tail eight-point grouting technique is being developed for filling.