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.

The present invention is directed to processes for making cementitious construction material, in particular magnesium oxychloride (MOC) cementitious construction material (e.g., MOC boards). The processes relate to one or more operations of the overall material production process, including material storage and handling, mixing of materials, curing to form magnesium oxychloride cement, board handling, and/or packaging. Various processes of the present invention involve process control strategies and/or algorithms to provide improved processes for producing construction material. In particular, the processes of the present invention provide improvements in board properties as detailed below (e.g., racking strength), speed of board production, economics of board production, reduction in complexity of manufacture, improvements in consistency of board manufacture, and improvements in quality control.

The present invention relates to a process for producing a redispersible dispersion powder, to the redispersible dispersion powder obtainable by this process, to an aqueous dispersion obtainable by step (1) of this process, and to a building material composition comprising the redispersible dispersion powder and/or the aqueous dispersion, to the use of the redispersible dispersion powder in a building material composition and to the use of the aqueous dispersion for production of a redispersible dispersion powder.

Disclosed is a CO.sub.2 solidified fiber cement board and its preparation method. The matrix composition of the fiber cement board prepared in this disclosure is calcium carbonate, which has high compactness, and the crystal form of calcium carbonate is adjusted by adding shell powder to improve the toughness of the matrix, so that the fiber cement board has excellent mechanics and durability performance. In addition, the preparation process does not require high temperature maintenance, and has the characteristics of normal temperature preparation, which creates conditions for the introduction of organic synthetic fibers, so that the organic synthetic fibers can further improve the brittleness of cement fiberboard. While reducing energy consumption, the preparation process can also effectively solve the problem that excessive pressure is easily generated in the fiberboard under high temperature conditions in the existing high-temperature and high-pressure curing process.

Disclosed is a CO.sub.2 solidified fiber cement board and its preparation method. The matrix composition of the fiber cement board prepared in this disclosure is calcium carbonate, which has high compactness, and the crystal form of calcium carbonate is adjusted by adding shell powder to improve the toughness of the matrix, so that the fiber cement board has excellent mechanics and durability performance. In addition, the preparation process does not require high temperature maintenance, and has the characteristics of normal temperature preparation, which creates conditions for the introduction of organic synthetic fibers, so that the organic synthetic fibers can further improve the brittleness of cement fiberboard. While reducing energy consumption, the preparation process can also effectively solve the problem that excessive pressure is easily generated in the fiberboard under high temperature conditions in the existing high-temperature and high-pressure curing process.

A process for preparing a cationic latex modified hydrocarbon binder emulsion comprising the steps of: (a) preparing a cationic copolymer latex emulsion by an emulsion polymerisation of polymerizable monomers, said polymerizable monomers comprising A—one or more non-ionic acrylate ester and/or methacrylate ester monomer(s), and B—optionally styrene monomer and/or one or more non-ionic styrene derivative monomer(s), C—optionally one or more cross-linking monomer(s) having two or more ethylenically unsaturated (C═C) double bonds susceptible to free radical copolymerisation, D—optionally one or more epoxy functional monomer(s) having one C═C double bond susceptible to free radical copolymerisation and one epoxide functional group, wherein said polymerizable monomers do not comprise any aliphatic conjugated diene monomer, in presence of a cationic stabilizing surfactant, and (b) adding the cationic copolymer latex emulsion resulting from step (a) to a cationic hydrocarbon binder emulsion, or (b′) adding the cationic copolymer latex emulsion resulting from step (a) to an emulsifier solution, said emulsifier solution comprising water, one or more cationic surfactant(s), one or more acid(s) and optionally additives to provide a mixture, and adding the resulting mixture to hydrocarbon binder; to form a cationic latex modified hydrocarbon binder emulsion.

The invention discloses a strontium ferrite-based sacrificial mortar and its preparation method, the strontium ferrite-based sacrificial mortar mainly comprises 720-1000 parts of sulphoaluminate cement, 100-300 parts of strontium ferrite, 600-650 parts of quartz sand, 400-450 parts of water and 0.01-35 parts of superplasticizer. The preparation process is simple, and the strontium ferrite-based sacrificial mortar can be prepared by using a conventional forced single horizontal shaft concrete mixer. The obtained mortar has excellent working performance, compressive strength and corrosion resistance. It can be used in the current third and future fourth generation nuclear power plant core catchers, and has obvious engineering application value.

A method of reducing hydrogen sulfide emissions from an asphalt or bitumen composition comprises releasing a solid hydrogen sulfide scavenger from an additive package, which comprises the solid hydrogen sulfide scavenger disposed in a sealed pouch; and contacting the asphalt or bitumen composition with the released solid hydrogen sulfide scavenger. The sealed pouch is formed from a pouch material, which includes an polyethylene, a polypropylene, an ethylene propylene copolymer, a polystyrene, a polylactic acid, a polyamide, a polyester, a polystyrene, an ethylene vinyl acetate copolymer, an ethylene vinyl alcohol copolymer, a polyvinylpyrrolidone, an ethylene vinylpyrrolidone copolymer, a vinylpyrrolidone vinyl acetate copolymer, a polyvinyl acetate, a polyvinyl alcohol, a polyethylene oxide, a polyethylene glycol, polyvinylidene chloride, a polysaccharide or its derivative, or a combination comprising at least one of the foregoing.

Cementitious compositions comprising a hydraulic cementitious material, a compound selected from the group consisting of a polyhydroxy aromatic compound, a polycarboxylic acid-containing compound or a salt thereof, ascorbic acid or a salt thereof, or a combination thereof, and a particulate material or a water soluble silicate-containing material that interacts with the compound are described herein. The polyhydroxy aromatic compound can be a water soluble compound having from two to thirty hydroxyl groups. The particulate material can exhibit a particle size distribution, wherein at least about 90% by weight of the particles have a diameter of less than 2 mm. Suitable particulate materials include nanoparticles and microparticles. The cementitious compositions can be used to form building materials. The cementitious compositions are especially suited for inhibiting corrosion of reinforcing steel bars embedded in concrete mixtures. Methods of making and using the cementitious composition are also disclosed.

The invention relates to an anti-filming surface-active admixture for hydraulic binders, including at least one fatty alcohol and at least one oil, to the method for preparing same, and to a method for preparing a hydraulic binder composition suitable for the manufacture of screeds or concretes, comprising the step of adding, to the hydraulic binder composition, the admixture according to the invention in a metered amount of 0.1 to 5 wt % with respect to the weight of the hydraulic binder.