Disclosed is a hydraulically and chemically bonding refractory cement, which includes a caustic magnesia component having a BET specific surface area of at least 0.5 m.sup.2/g, and a carboxylic acid component, wherein the carboxylic acid component consists of at least one carboxylic acid that is only slightly water soluble and/or has a low dissolution rate in aqueous solutions, and which carboxylic acid component is capable of generating at least one soluble magnesium salt upon contact of the cement with water. Also disclosed is a corresponding refractory material containing the magnesia cement and to uses thereof for the manufacture of products useful in various industries.

A cement-based tile formed from a mixture comprising: a cement in the range of about 0.1 to 88% by wet weight percent; a secondary material in the range of about 0.1 to 50% by wet weight percent, the secondary material comprising limestone, sand, silica sand, gypsum, silica fume, fumed silica, Plaster of Paris, calcium carbonate, fly ash, slag, rock, or a combination thereof; a reinforcement fiber in the range of about 0.5 to 20% by wet weight percent, the reinforcement fiber comprising cellulose fiber, glass fiber, plastic fiber, polypropylene fiber, polyvinyl alcohol (PVA) fiber, homopolymer acrylic fiber, alkali-resistant fiber, or a combination thereof; a rheology modifying agent in the range of about 0.5 to 10% by wet weight percent; a water in the range of 10 to 60% of a total wet material weight; and wherein the mixture is extruded or molded to form the cement-based tile.

The present invention provides an admixture composition comprising a liquid suspension of colloidal silica, siloxane, and polycarboxylate polymer cement dispersant for enhancing early age strength, finishability, and other properties in hydratable cementitious compositions such as concrete (e.g., shotcrete). An inventive method involves mixing the components together in a specific sequence, thereby to obtain a stable liquid suspension. This attainment of a stable liquid suspension is surprising and unexpected because (i) the polycarboxylate polymer cement dispersant and siloxane components are incompatible and immiscible with one another; and (ii) that colloidal silica and siloxane compound are incompatible and immiscible with one another. Yet, the present inventors achieved an additive in the form of a stable liquid suspension which can be conveniently dosed into concretes and shotcrete mixtures, to enhance early age strength, and to improve workability and rheology in terms of finishability of concrete surfaces and improved rebound performance in shotcrete applications.

A hydraulic composition including water; a hydraulic binder; at least one setting retarder; and at least one polysaccharide; the weight ratio of the water/hydraulic binder being greater than 1.5, methods of using the composition as a mixture in a grout and a corresponding method for preparing a grout and the grout thereby obtained.

A hydraulic composition including water; a hydraulic binder; at least one setting retarder; and at least one polysaccharide; the weight ratio of the water/hydraulic binder being greater than 1.5, methods of using the composition as a mixture in a grout and a corresponding method for preparing a grout and the grout thereby obtained.

A borehole cement slurry additive that is capable of suppressing the generation of free water from cement slurries in any environment, whether cold regions, mild regions, or hot regions; and a method for storing the same. The borehole cement slurry additive contains: an aqueous dispersion of silica having an average particle size of 3-200 nm as determined via dynamic light scattering; and a compound having an alcoholic hydroxyl group as a dispersion stabilizer, the compound being included in an amount of 1-30 mol per 1,000 g dispersion medium in the aqueous silica dispersion.

A borehole cement slurry additive that is capable of suppressing the generation of free water from cement slurries in any environment, whether cold regions, mild regions, or hot regions; and a method for storing the same. The borehole cement slurry additive contains: an aqueous dispersion of silica having an average particle size of 3-200 nm as determined via dynamic light scattering; and a compound having an alcoholic hydroxyl group as a dispersion stabilizer, the compound being included in an amount of 1-30 mol per 1,000 g dispersion medium in the aqueous silica dispersion.

Provided herein is a composition for use as a hardening regulator, e.g. hardening accelerator or hardening retarder, for building materials, as well as methods for producing thereof. The composition is characterized by a biphasic nature in which solid calcium silicate nanoparticles are dispersed in an aqueous solution comprising inorganic water soluble iron, and possibly zinc, silicate and calcium, species. Additional components such as inorganic ions and silica nanoparticles can be present. Depending on the relative ratio of each component, the composition can be used either for retarding or for accelerating the hardening process of a building material such as cement or concretes. The so-obtained building material further shows an enhanced strength upon compressive forces applied thereon.

A simulated concrete mixture combines aggregate, sand, mortar clay, and additive. The mixture is hydrated with enough water or a hydrating solution to create a simulated concrete material having a desired slump. Useful aggregates include any type of aggregate used as a base for concretes, and useful additives include soaps, detergents, surfactants, and flocculants. The material can be refreshed with water or a refresher solution. The hydrating solution and refreshing solution are solution of water and additive. The simulated concrete material can be manipulated until its consistency becomes unworkable, after which it can be refreshed with water or refresher solution.

The present invention relates to construction chemical compositions comprising a bisulfite adduct of glyoxylic acid or a salt or mixed salt thereof and an inorganic binder. The composition is useful as a hydration control agent of the inorganic binder.