A corrosion-resistant member may include alumina ceramics containing α-alumina and anorthite. The alumina ceramics may contain 0.4% by mass or more of Ca and Si in total in terms of CaO and SiO.sub.2, respectively, and a mass ratio of CaO/SiO.sub.2 may fall within a range of 0.5 to 2. Moreover, a ratio B/A of X-ray diffraction peak intensity B for (004) plane of the anorthite to X-ray diffraction peak intensity A for (104) plane of the α-alumina in a surface of the alumina ceramics, may be 0.01 or more.

Provided are a concrete manufacturing method capable of preventing neutralization of concrete and oxidation of a reinforcing rod in reinforced concrete, and a method for manufacturing a reinforced concrete structure using the same. The concrete manufacturing method uses nitrogen dissolved water and is characterized by including: a step of generating nitrogen dissolved water by injecting nitrogen gas into water to replace oxygen and carbon dioxide dissolved in the water with nitrogen; and a step of generating a ready-mixed concrete by kneading the nitrogen dissolved water, cement, an aggregate, and an admixture. The method for manufacturing a reinforced concrete structure is characterized by forming a reinforced concrete structure using a ready-mixed concrete manufactured by a concrete manufacturing method using nitrogen dissolved water.

A method of producing a carbonated composite material is described that includes: providing a carbonatable cementitious material in particulate form; mixing the carbonatable cementitious material with water to produce a mix; forming a predetermined shape with the mix, wherein the predetermined shape has an initial pore structure containing an initial pore solution having a first pH; pre-conditioning the predetermined shape to remove a predetermined amount of the water from the predetermined shape to produce a pre-conditioned shape; carbonating the pre-conditioned shape in an environment comprising carbon dioxide to produce a modified pore structure containing a modified pore solution having and a second pH, wherein the difference between the first pH and the second pH is represented by a ΔpH, and the ΔpH is 1.0 or less, 0.75 or less, 0.5 or less, 0.25 or less, or about 0.0. A calcium silicate composition including solid components and liquid components having improved pore solution pH stability is also disclosed.

According to some embodiments, a curable mixture configured to set in the presence of water, wherein the mixture comprises magnesium oxide, a primary cementitious component and at least one accelerant. A proportion by weight of the primary cementitious component is 80% to 120% of a proportion of magnesium oxide by weight.

A corrosion resistant member has a portion to be exposed to a corrosive gas. The portion to be exposed to the corrosive gas is formed of a ceramic sintered body. The mean width (Rsm) of profile elements of a surface of the ceramic sintered body is 25 μm or less, and the ratio (Rsm/Ra) of the mean width (Rsm) of the profile elements to the arithmetic mean roughness (Ra) of the surface of the ceramic sintered body is 4,000 or less.

The corrosion-preventing additive for reinforced concrete is a concrete additive for preventing corrosion of steel rebars in steel-reinforced concrete. The corrosion-preventing additive is a solution with an organic solvent, the solute being either gallic acid (3,4,5-trihydroxybenzoic acid), at least one ester of gallic acid, or combinations thereof. The weight-to-volume concentration of the solute to the organic solvent may be between 1% and 10% w/v. Reinforced concrete may be made using the corrosion-preventing additive by mixing the corrosion-preventing additive with a conventional concrete mixture (i.e., a mixture of an aggregate, water, and cement), with at least one steel rebar being embedded in the mixture, similar to conventional steel rebar reinforced concrete. The concentration of the corrosion-preventing additive with respect to the cement of the mixture may be between 0.0125 wt % and 1.0 wt %.

Clay polymer nanocomposites may be mixed with an aggregate material and heat treated to make a structural stabilizer. In an embodiment, the composition is a structural stabilizer resulting from thermal casting and heat treatment. The structural stabilizer does not include cement or water. The heat treatment may be any suitable heat application, including microwave heating, convection oven heating or heating in thermal mixers. The structural stabilizer can be rapidly synthesized to provide high compressive strength and high homogeneity, and to be substantially free of fractures and cracks. Methods of repairing cracks in concrete and stabilizing soil, rock and sand dune formations using the structural stabilizer include thermal casting. Thermal casting ductile concrete molds can include a coating of aluminum foil. The concrete is self-compact, ecofriendly, lightweight, self-repairing and self pre-stressing with homogeneity and low density. The concrete resists steel corrosion, sudden collapse, and does not produce pollution.

A cementitious protective coating material including a mixture of water, one or more of silicon dioxide/sodium silica pozzolans, anhydrous or hydrous sodium or potassium metasilicate; a rheology enhancing admixture; sodium tetraborate, sodium citrate dihydrate, citric acid, or boric acid; and a micro-fiber.

A cementitious protective coating material including a mixture of water, one or more of silicon dioxide/sodium silica pozzolans, anhydrous or hydrous sodium or potassium metasilicate; a rheology enhancing admixture; sodium tetraborate, sodium citrate dihydrate, citric acid, or boric acid; and a micro-fiber.

A water-based mixture of multi compounds for adding to fresh concrete to protect the concrete against moisture and moisture-associated problems. A hygroscopic and hydrophilic behavior of its crystallization system within a concrete matrix minimizes moisture transmission through capillaries and connected voids. As a result, the mixture may reduce moisture related problems, such as damage caused by repeated freeze and thaw cycles and chloride ion penetration as from deicing salts, as well as alkali-silica reactions, and other problems.