Abstract: Disclosed herein is an alkali silicate based protective coating for metal surfaces. The coating is substantially defect free, and provides for an impedance of as high as one million ohms or more at a frequency of about 10 Hz.

Abstract: The present invention relates to hydraulically bonded cement compositions and methods. More particularly, the present invention is directed to novel compositions and methods of hydrating hydraulic cement without mechanical mixing of the cement and water. The present invention includes materials prepared by manipulating under pressure powdered hydraulic cement compositions using known or novel powder packing, casting, or expanding techniques, such that air within the powdered hydraulic cement is substantially removed while the cement is formed into a self-supporting near net final position. Thereafter, the formed hydraulic cement is hydrated without mechanical mixing of the cement and water.

Abstract: Incorporation of solid removable aggregates into powdered cement which later completely dissolve, evaporate, volatilize, or melt leaving voids in the cement composition is discussed. Cementitious articles are prepared by manipulating powdered hydraulic cement or cement paste compositions into mechanically self-supporting structures of a predetermined configuration and thereafter hydrating the hydraulic cement compositions without mechanical mixing of the cement and water.

Abstract: Cement compositions and processes for improving the bond between new hydrating cement-based materials and the surface of "old" cement-based substrates are disclosed. A mechanically and chemically integral bond is created between the surfaces of the cement-based materials by moistening the old cement-based surface, exposing the moist surface to carbon or carbonate sources (such as with carbon dioxide) and then applying a new hydrating cement-based material thereon. The treatment of the surface of the cement-based substrate as described above creates an aqueous phase chemistry thereon which is compatible to the aqueous phase chemistry of the hydrating cement-based materials applied thereafter. The compatibility of the aqueous phase chemistries results in a mechanically and chemically integral bond formed between the surface of the old cement-based surface and the hydrating cement-based materials.

Abstract: Method/apparatus for making a composite wherein reinforcement or filler material, such as, for example, ceramic fibers or whiskers, are confined in a microwave-transparent envelope, the reinforcement or filler material is microwave heated, and a gaseous reactant stream is flowed through the envelope so as to infiltrate interstices of the heated reinforcement or filler material and chemically vapor deposit a matrix, such as a ceramic matrix, from the interior toward the exterior of the heated material. The envelope imparts a desired shape and size to the composite. After infiltration, the envelope typically is removed from the composite.

Abstract: The present invention relates to hydraulically bonded cement compositions and methods of manufacture. Hydraulically bonded cement compositions and methods of manufacture include materials prepared by manipulating under pressure powdered hydraulic cement compositions using known or novel powder packing, casting, or expanding techniques, such that air within the powdered hydraulic cement is successfully removed while the cement is formed into a self-supporting near net final position. Thereafter, the formed hydraulic cement article is hydrated without mechanical mixing of the cement and water.

Abstract: Incorporation of solid removable aggregates into powdered cement which later completely dissolve, evaporate, volatilize, or melt leaving voids in the cement composition is discussed. Cementitious articles are prepared by manipulating powdered hydraulic cement or cement paste compositions into mechanically self-supporting structures of a predetermined configuration and thereafter hydrating the hydraulic cement compositions without mechanical mixing of the cement and water.

Abstract: The process for producing a paste of improved quality. In one aspect, the process comprises allowing hydraulic cement and water to mix sufficiently to reach early age equilibrium, exposing the mixing water and cementitious material to a carbon source selected from the group consisting of CO.sub.2, CO, carbonate salts and mixtures thereof, and then allowing the resulting mixture to again reach early age equilibrium.

Abstract: Novel cementitious contaminant barriers are formed by positioning a hydraulic cement composition into a predetermined configuration and then hydrating the cement composition. The contaminant barriers of the present invention include at least one liquid, gas, or ion getter capable of binding with or absorbing liquids, ions, or gases which may penetrate the barrier. The contaminant barriers of the present invention may be engineered to include mixtures of different getters, single and multiple layers of different getters, multiple layers of cement and getters, and a host of different getter, cement, mixture, and layer combinations.Novel waste containers are advantageously prepared utilizing contaminant barriers within the scope of the present invention. The waste containers may be prepared by surrounding waste material with at least one getter and with a powdered hydraulic cement composition and then compressing the cement and getter around the waste material.

Abstract: Novel cementitious containers for storage of hazardous waste are disclosed having an inner layer of substantially unhydrated cement in contact with the hazardous waste and an outer layer of hydrated cement. Cementitious hazardous waste containers may be prepared by compressing powdered hydraulic cement around solid hazardous waste materials and then hydrating an outer layer of the powdered hydraulic cement. An inner layer of powdered hydraulic cement remains unhydrated and capable of reacting with any water which might breach the outer layer or originate with the hazardous waste itself. The inner layer of powdered hydraulic cement is also capable of reacting with any carbon dioxide or carbon monoxide generated by decomposition of organic waste materials.