Processes are disclosed for producing gypsum-based products from a gypsum slurry. Additives or combinations of additives for improving compressive strength, fluidity and/or set time of the gypsum product are mixed in intimate contact with raw gypsum prior to or during grinding and/or flash calcination to form stucco. The stucco is used to prepare a gypsum slurry which is shaped and sets to form the gypsum product.

Processes are disclosed for producing gypsum-based products from a gypsum slurry. Additives or combinations of additives for improving compressive strength, fluidity and/or set time of the gypsum product are mixed in intimate contact with raw gypsum prior to or during grinding and/or flash calcination to form stucco. The stucco is used to prepare a gypsum slurry which is shaped and sets to form the gypsum product.

Mineral binder compositions with accelerated setting and/or curing including a mineral binder, at least one free-radical initiator, and at least one catalyst for the at least one free-radical initiator. The mineral binder compositions accelerated setting and hardening and are especially useful for applications at low temperatures and even below 0° C.

The present application relates to an additive component comprising a component A and a component B, wherein component A comprises at least one hardening retarder selected from glyoxylic acid, salts thereof, condensation or addition products of glyoxylic acid or salts thereof, and mixtures thereof, and component B comprises at least one hardening accelerator selected from calcium-silicate-hydrate, calcium formate, calcium nitrate, calcium chloride, calcium hydroxide, lithium carbonate, lithium sulfate, potassium sulfate, sodium sulfate, ground gypsum, and combinations thereof, in 3D printing of a construction material composition.

The present application relates to an additive component comprising a component A and a component B, wherein component A comprises at least one hardening retarder selected from glyoxylic acid, salts thereof, condensation or addition products of glyoxylic acid or salts thereof, and mixtures thereof, and component B comprises at least one hardening accelerator selected from calcium-silicate-hydrate, calcium formate, calcium nitrate, calcium chloride, calcium hydroxide, lithium carbonate, lithium sulfate, potassium sulfate, sodium sulfate, ground gypsum, and combinations thereof, in 3D printing of a construction material composition.

A slag-based binder has at least one slag, optionally at least one CO.sub.3-containing mineral powder, optionally at least one co-binder different from the slag and mineral powder, at least one activator of the water/slag reaction, optionally at least one co-activator different from the one activator, at least one chelatant and/or at least one source of chelatant, said chelatant being preferably a scale inhibitor, and, optionally, at least one superplasticizer different from the chelatant. A kit is provided to make the binder. The binder is combined with an aggregate to make a dry concrete or mortar. A method for the preparation of a wet formulation (binder/water or concrete-mortar/water) is disclosed as is method of manufacturing buildings or civil engineering works or elements thereof, coatings, fillers, screeds, tiles, adhesives and/or internal or external insulation systems from the wet formulation. The binder is a substitute to OPC-based compositions and is environmentally friendly.

A hydrogel forming composition comprising at least one water-soluble (meth)acrylic compound, at least one free radical initiator, at least one catalyst for free radical formation, and water, wherein the at least one catalyst for free radical formation is an amine compound of formula (I). The invention is also directed to a multiple-component composition, to a hydrogel, to use of the hydrogel forming composition for sealing of constructions, tunnels, or mines or for soil stabilization, to a method for sealing and/or filling of cracks, voids, flaws and cavities in a building structure, and to a use of at least one tertiary amine compound for reducing the gelling time of a hydrogel forming mixture.

A hydrogel forming composition comprising at least one water-soluble (meth)acrylic compound, at least one free radical initiator, at least one catalyst for free radical formation, and water, wherein the at least one catalyst for free radical formation is an amine compound of formula (I). The invention is also directed to a multiple-component composition, to a hydrogel, to use of the hydrogel forming composition for sealing of constructions, tunnels, or mines or for soil stabilization, to a method for sealing and/or filling of cracks, voids, flaws and cavities in a building structure, and to a use of at least one tertiary amine compound for reducing the gelling time of a hydrogel forming mixture.

Provided are: a coated sand having improved fluidity and being capable of improving a filling rate of a casting mold to be obtained; and a coated sand for advantageously manufacturing a casting mold having excellent strength, which coated sand provides a casting mold with good mold-releasability and collapsibility, gives cast products a favorable casting surface, and effectively improves sand adhesion on cast products. The coated sand is formed as a dry granular material having fluidity at room temperature, in which the surface of a refractory aggregate is coated with a solid layer of a water-soluble inorganic binder, and spherical particles of silicone resin having binder-repellency exist on the surface of the binder layer, or form a layer on the surface of the binder layer, a part of the spherical particles being not covered with the water-soluble inorganic binder and being exposed.

Provided are: a coated sand having improved fluidity and being capable of improving a filling rate of a casting mold to be obtained; and a coated sand for advantageously manufacturing a casting mold having excellent strength, which coated sand provides a casting mold with good mold-releasability and collapsibility, gives cast products a favorable casting surface, and effectively improves sand adhesion on cast products. The coated sand is formed as a dry granular material having fluidity at room temperature, in which the surface of a refractory aggregate is coated with a solid layer of a water-soluble inorganic binder, and spherical particles of silicone resin having binder-repellency exist on the surface of the binder layer, or form a layer on the surface of the binder layer, a part of the spherical particles being not covered with the water-soluble inorganic binder and being exposed.