A process for preparing powdered dispersants comprising at least 90% by weight of at least one copolymer CP of the polycarboxylate ether type. The powdered dispersants can be easily dispersed in water. The invention also relates to the use of such powdered dispersants in mineral binder compositions, in particular dry mortars, concrete or gypsum formulations.

A regulating cementitious material for promoting hydration of Portland cement is provided. The regulating cementitious material may include ingredients by weight as follows: ye'elimite, 27˜68 parts; anhydrite, 29˜68 parts; lithium nitrite, 2˜5 parts; ethylene glycol monoisopropanolamine, 0.14˜0.29 parts; triethanolamine acetate, 0.04˜0.09 parts; and polyglycerol, 0.04˜0.09 parts. An early strength of Portland cement can be improved through a cooperative hydration between minerals and an enhanced solubilization of a complexing agent.

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 preventing formation of rust-colored stains on the surface of a hydraulic composition includes mixing the hydraulic composition with an additive for hydraulic binder including at least a dialkanolamine including from 2 to 8 carbon atoms, and at least a polyol preferably chosen from a diol, a triol, a tetraol and mixtures thereof. Other uses include a grinding aid for hydraulic binder precursor, and/or improving the compressive strength of a set hydraulic composition.

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).

A concrete and asphalt repair coating formulation includes a cement component and an aggregate component. The cement component includes a calcium sulfoaluminate cement and a Portland cement. The aggregate component includes coarse aggregates between 125-500 microns in diameter and fine aggregates between 5-62.5 microns in diameter.

Technical fields of building external wall decoration and material manufacturing, providing a mildewproof and antirot high-strength cement particle board and a preparation method thereof. The preparation method includes: (1) sequentially carbonizing and water-washing a shaving, and mixing the obtained carbonized shaving with a cement gelling agent, a curing agent aqueous solution and water to obtain a mixture; (2) molding the mixture to obtain a pre-molded material; and (3) sequentially curing and drying the pre-molded material to obtain the mildewproof and antirot high-strength cement particle board. Compared to ordinary cement particle board, which is not subjected to carbonization treatment and water-washing, the cement particle board of the present invention can effectively avoid mildew and rot, and can significantly improve the mechanical strength and durability thereof, helping to extend the service life of the cement particle board.

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 preparation method for a concrete additive for a maritime work environment includes: S1, compounding a volcanic ash material containing aluminum oxide and lime in proportion, loading a mixture into a sugar coating machine, and spraying a proper amount of alcohol, to prepare spherical particles; S2, adding the spherical particles in S1 and cement into the sugar coating machine, uniformly spraying deionized water in a rotating process, and coating surface layers of the spherical particles with a layer of cement for maintenance; and S3, placing the maintained particles in S2 into a hydrophobic emulsion, and coating the surface layers of the particles with a layer of hydrophobic emulsion, to obtain a concrete additive.