A cementitious multi-component mortar system contains finely ground granulated blast-furnace slag with a grinding fineness in the range of from 5,000 to 15,000 cm.sup.2/g. The cementitious multi-component mortar system can be used as an inorganic chemical fastening system for anchoring elements in mineral substrates.

A curing accelerator composition for building chemical mixtures comprises a mineral constituent and a polymeric water-soluble dispersant. The mineral constituent comprises a semi-ordered calcium silicate hydrate having an apparent crystallite size of 15 nm or less and less than 35% by weight of crystalline phases other than the semi-ordered calcium silicate hydrate. The composition displays a more pronounced accelerating effect than comparative compositions in which the mineral component comprises a calcium silicate hydrate having a higher degree of crystallinity.

This invention relates to a solidifying agent for solidifying radioactive waste, and more particularly to a solidifying-agent composition for solidifying radioactive waste, including alumina cement and a gypsum powder. The solidifying-agent composition including alumina cement and a gypsum powder is capable of effectively minimizing an increase in the volume of a solidified radioactive waste product to a level satisfying physical and chemical safety regulations upon the solidification of radioactive waste.

This invention relates to a solidifying agent for solidifying radioactive waste, and more particularly to a solidifying-agent composition for solidifying radioactive waste, including alumina cement and a gypsum powder. The solidifying-agent composition including alumina cement and a gypsum powder is capable of effectively minimizing an increase in the volume of a solidified radioactive waste product to a level satisfying physical and chemical safety regulations upon the solidification of radioactive waste.

A concrete durability protection method is provided, including following steps: Step one: rinsing the concrete surface; Step two: spraying agent A material or alternately spraying agent B material and agent A material at the wet surface of the concrete; Step three: repeating step two. The beneficial effects of the present invention include: nanoscale active silicate penetrates into the concrete surface layer within a certain depth and reacts with free calcium ions within the concrete to form C—S—H crystalline, thereby improving the compactness of the concrete surface layer within a certain depth, repairing defects in the concrete surface layer within a certain depth, such as the capillary interstices, pores, microcracks, etc., so as to effectively improve the durability of concrete. The unreacted nanoscale active silicate material has permanent activity. It could recover its activity when the concrete absorbs moisture, and continue to react with free calcium ions in the concrete to quickly form C—S—H crystals, realizing the permanent concrete durability protection.

A concrete durability protection method is provided, including following steps: Step one: rinsing the concrete surface; Step two: spraying agent A material or alternately spraying agent B material and agent A material at the wet surface of the concrete; Step three: repeating step two. The beneficial effects of the present invention include: nanoscale active silicate penetrates into the concrete surface layer within a certain depth and reacts with free calcium ions within the concrete to form C—S—H crystalline, thereby improving the compactness of the concrete surface layer within a certain depth, repairing defects in the concrete surface layer within a certain depth, such as the capillary interstices, pores, microcracks, etc., so as to effectively improve the durability of concrete. The unreacted nanoscale active silicate material has permanent activity. It could recover its activity when the concrete absorbs moisture, and continue to react with free calcium ions in the concrete to quickly form C—S—H crystals, realizing the permanent concrete durability protection.

Corrosion-resistant refractory binder compositions may be formed with a calcium ion source, high-alumina refractory aluminosilicate pozzolan, and water. Any one or more of such components may individually be non-cementitious. Examples of high-alumina refractory aluminosilicate pozzolan include crushed firebrick; firebrick grog; and mixtures of silicate and any one or more of corundum, high-alumina ceramic, and bauxite; refractory mortar; fire clay; mullite; fused mullite; and combinations thereof, among others. A binder composition may be mixed with sufficient amount of water to form a slurry, which slurry may be introduced into a subterranean formation (e.g., via a wellbore penetrating the subterranean formation). A plurality of the non-cementitious components may react in the presence of water when exposed to suitable conditions so as to enable the binder composition to set. Such compositions, once set, may exhibit enhanced corrosion and/or heat resistance as compared to other binder compositions.

Corrosion-resistant refractory binder compositions may be formed with a calcium ion source, high-alumina refractory aluminosilicate pozzolan, and water. Any one or more of such components may individually be non-cementitious. Examples of high-alumina refractory aluminosilicate pozzolan include crushed firebrick; firebrick grog; and mixtures of silicate and any one or more of corundum, high-alumina ceramic, and bauxite; refractory mortar; fire clay; mullite; fused mullite; and combinations thereof, among others. A binder composition may be mixed with sufficient amount of water to form a slurry, which slurry may be introduced into a subterranean formation (e.g., via a wellbore penetrating the subterranean formation). A plurality of the non-cementitious components may react in the presence of water when exposed to suitable conditions so as to enable the binder composition to set. Such compositions, once set, may exhibit enhanced corrosion and/or heat resistance as compared to other binder compositions.

A powder adhesive composition having cement, a dispersible polymer powder; and at least 10% volume of the powder adhesive is an expanded perlite. The cement is at a ratio of between 600-1000% of the mass of the expanded perlite. The powder adhesive composition is an adhesive, and the adhesion strength of the adhesive, is over 0.4 MPa, after 28 days, and after water immersion for at least 20 days.

A powder adhesive composition having cement, a dispersible polymer powder; and at least 10% volume of the powder adhesive is an expanded perlite. The cement is at a ratio of between 600-1000% of the mass of the expanded perlite. The powder adhesive composition is an adhesive, and the adhesion strength of the adhesive, is over 0.4 MPa, after 28 days, and after water immersion for at least 20 days.