An anti-radiation concrete comprising a geopolymer is described. In an implementation, the anti-radiation concrete comprises a mixture of at least two aqueous alkaline activators, fine aggregate, and coarse aggregate from high density metal-containing rocks.

A composition consisting essentially of (a) 1 to 30% by weight of a 1 to 90% by weight aqueous phosphoric acid and/or a hydrogen phosphate; (b) 1 to 40% by weight of a compound selected from the group of oxides, hydroxides and oxide hydrates of magnesium, calcium, iron, zinc and copper; (c) 40 to 95% by weight of a particulate filler selected from the group of glass; mono-, oligo- and polyphosphates of magnesium, calcium, barium and aluminium; calcium sulphate; barium sulphate; simple and complex silicates; simple and complex aluminates; simple and complex titanates; simple and complex zirconates; zirconium dioxide; titanium dioxide, aluminium oxide; silicon oxide; silicon carbide; aluminium nitride; boron nitride and silicon nitride; (d) 1 to 10% by weight of an urea compound selected from the group consisting of imidazolidine-2-on, allantoin and imidazolidinyl urea; and (e) 0 to 15% by weight of a component differing from (a) to (d).

A composition consisting essentially of (a) 1 to 30% by weight of a 1 to 90% by weight aqueous phosphoric acid and/or a hydrogen phosphate; (b) 1 to 40% by weight of a compound selected from the group of oxides, hydroxides and oxide hydrates of magnesium, calcium, iron, zinc and copper; (c) 40 to 95% by weight of a particulate filler selected from the group of glass; mono-, oligo- and polyphosphates of magnesium, calcium, barium and aluminium; calcium sulphate; barium sulphate; simple and complex silicates; simple and complex aluminates; simple and complex titanates; simple and complex zirconates; zirconium dioxide; titanium dioxide, aluminium oxide; silicon oxide; silicon carbide; aluminium nitride; boron nitride and silicon nitride; (d) 1 to 10% by weight of an urea compound selected from the group consisting of imidazolidine-2-on, allantoin and imidazolidinyl urea; and (e) 0 to 15% by weight of a component differing from (a) to (d).

A cementitious composition suitable for formation by three-dimensional printing according to the present invention is aimed at developing a cementitious composition suitable for formation by three-dimensional printing which gives good stability to the extruded material coming out of a nozzle. The workpiece obtained from the three-dimensional printing formation therefore has fewer errors and greater fineness and is easier to use. The cementitious composition comprises cement, fine aggregate, powdered limestone, expanding admixture, retarding admixture, thickener and rheology modifier.

A cementitious composition suitable for formation by three-dimensional printing according to the present invention is aimed at developing a cementitious composition suitable for formation by three-dimensional printing which gives good stability to the extruded material coming out of a nozzle. The workpiece obtained from the three-dimensional printing formation therefore has fewer errors and greater fineness and is easier to use. The cementitious composition comprises cement, fine aggregate, powdered limestone, expanding admixture, retarding admixture, thickener and rheology modifier.

An example cement includes a naturally occurring silicate bound in an organic binder, a metal oxide, and a chemical activator. The chemical activator is in an effective amount, for dissolving the binder, at least in part, so that the silicate reacts with other components of the cement, the silicate participates in crystal growth; and the cement is a structural load bearing cement.

An example cement includes a naturally occurring silicate bound in an organic binder, a metal oxide, and a chemical activator. The chemical activator is in an effective amount, for dissolving the binder, at least in part, so that the silicate reacts with other components of the cement, the silicate participates in crystal growth; and the cement is a structural load bearing cement.

A waterproofing agent for concrete includes: 1-60 parts by weight of ferric ions; 1-60 parts by weight of carboxylate ions; 1-40 parts by weight of 8-hydroxyquinoline; and 1-50 parts by weight of pyrosulfate ions.

A waterproofing agent for concrete includes: 1-60 parts by weight of ferric ions; 1-60 parts by weight of carboxylate ions; 1-40 parts by weight of 8-hydroxyquinoline; and 1-50 parts by weight of pyrosulfate ions.

The present invention relates to a defoamer emulsion, which comprises at least one alkyl ether sulfate or sulfonate, at least one defoamer and water, wherein the alkyl in the alkyl ether sulfate or sulfonate is C.sub.6-C.sub.22 alkyl and the average droplet diameter of the emulsion is less than 300 nm. The present invention also provides a process for producing it, a polycarboxylate ether formulation comprising the defoamer emulsion and a cement composition comprising the polycarboxylate ether formulation. The defoamer emulsion of the present invention possesses high transmittance and excellent stability. The polycarboxylate ether formulation comprising the defoamer emulsion also shows excellent stability. The cement composition comprises the polycarboxylate ether formulation according to the present invention has a low air content.