Abstract: A vacuum heat-insulator (6) formed by tightly packaging a shaped product comprising acicular crystals of calcium silicate entangled in a three dimensional manner in a reduced pressure state in a container (2), (3), (4) composed of a composite film formed by laminating a metal foil, or vapor-depositing a metal or metal oxide to a plastic film, and having a thermal conductivity at 20.degree. C. of not more than 0.015 Kcal/m.hr..degree.C. This vacuum heat-insulator (6) brings about no environmental problems upon discarding caused by dusting, and is capable of displaying an excellent heat-insulating performance without using Freon.

Abstract: A carbon fiber-reinforced concrete containing a cement, a coarse aggregate, a fine aggregate, a carbon fiber and water, the carbon fiber having an average length not less than the maximum size of the coarse aggregate and also a tensile strength of at least 300 kgf/mm.sup.2.

Abstract: The present invention provides a short carbon fiber reinforced hydraulic composite material making the best use of physical properties of short carbon fibers incorporated as reinforcing material. Microparticles are deposited on the short carbon fibers in an amount of 0.5 to 3 wt. %. These microparticles also have a particle diameter of 5 microns or less.

Abstract: An inorganic fiber composed essentially of fine crystals of an aluminum compound, which contains at least 10% by weight of aluminum nitride and the rest of the aluminum compound being alumina.

Abstract: A calcium silicate shaped product comprises heat-resistant particles having a radiation energy absorptivity of at least 20% throughout the entire range of the wavelength of from about 2 to about 5.mu., as measured by a 0.1 wt. % KBr disc method.

Abstract: A process for preparing a calcium silicate shaped product comprises heat-reacting a calcareous source and a siliceous source dispersed in water to obtain an aqueous slurry containing a calcium silicate hydrate having a molar ratio of CaO/SiO.sub.2 being more than 1, adding a siliceous source to the aqueous slurry to bring the molar ratio of CaO/SiO.sub.2 to a level of from 0.85 to 1, and pressfilter-molding the aqueous slurry thereby obtained, followed by steam-curing and drying.

Abstract: A calcium silicate shaped product is produced by forming an aqueous slurry of calcium silicate hydrate obtained by reacting a calcareous source with a siliceous source dispersed in water under heating; molding said aqueous slurry and heat-treating said molded product under the condition providing the equations (I) and (II);100.ltoreq..theta..multidot.T (I)50.ltoreq..theta..ltoreq.300 (II)wherein .theta. represents a temperature of the inner part of the molded product (.degree.C.) and T represents a time (hour) and providing a percent water loss of the treated molded product of less than 25 wt. %, before drying or steam-curing and drying the molded product.

Abstract: A calcium silicate shaped product is prepared by forming an aqueous slurry of calcium silicate hydrate by reacting a calcareous source with a siliceous source in water as a dispersion under heating; molding said aqueous slurry to form a molded product having a bulk density of less than 0.6 g/cm.sub.3 ; curing said molded product, in a closed tank having a capacity of 1.5 to 30 times of the volume of said molded product at 140.degree. to 300.degree. C. by dry-heating without feeding steam, and drying the product.

Abstract: A molded gypsum product comprises a matrix of crystalline gypsum and reinforcing fibers of glass fiber and asbestos fiber uniformly distributed in said matrix in a multi-layer structure having at least one higher density layer and at least one lower density layer which is continuously adjacent to said higher density layer and having an average apparent bulk density of 0.3 to 0.9 g/cc.