A process for the manufacturing of a slurry containing nucleating agents which comprises reacting at least one source of a Ca containing compound with at least one source of a Si containing compound, in an aqueous media and in the presence of a doping agent selected from the group consisting of P, B, S, and mixtures thereof; wherein: (i) the reaction is carried out at a temperature comprised from 100 to 350? C.; (ii) the total molar ratio Ca/Si is 1.5-2.5, and (iii) the total molar ratio doping agent/Si is 0.01-2; provided that: (a) when the sole doping agent is P, the total molar ratio P/Si is 0.1-2; (b) when the sole doping agent is B, the total molar ratio B/Si is 0.01-2, and (c) when the sole doping agent is S, the total molar ratio S/Si is 0.1-2.

A process for the manufacturing of a slurry containing nucleating agents which comprises reacting at least one source of a Ca containing compound with at least one source of a Si containing compound, in an aqueous media and in the presence of a doping agent selected from the group consisting of P, B, S, and mixtures thereof; wherein: (i) the reaction is carried out at a temperature comprised from 100 to 350? C.; (ii) the total molar ratio Ca/Si is 1.5-2.5, and (iii) the total molar ratio doping agent/Si is 0.01-2; provided that: (a) when the sole doping agent is P, the total molar ratio P/Si is 0.1-2; (b) when the sole doping agent is B, the total molar ratio B/Si is 0.01-2, and (c) when the sole doping agent is S, the total molar ratio S/Si is 0.1-2.

The invention relates to a method for producing a calcium silicate hydrate-comprising hardening accelerator in powder form, which comprises the steps of (a) providing an aqueous suspension comprising calcium silicate hydrate; (b) mixing at least one calcium compound, selected from calcium acetate, calcium formate, calcium hydroxide, calcium oxide, and mixtures of two or more of said compounds, with the aqueous suspension comprising calcium silicate hydrate; and (c) drying the resulting mixture.

The invention also relates to the hardening accelerator obtainable by this method, to the use thereof, and to building material mixtures which comprise the hardening accelerator.

The invention relates to a method for producing a calcium silicate hydrate-comprising hardening accelerator in powder form, which comprises the steps of (a) providing an aqueous suspension comprising calcium silicate hydrate; (b) mixing at least one calcium compound, selected from calcium acetate, calcium formate, calcium hydroxide, calcium oxide, and mixtures of two or more of said compounds, with the aqueous suspension comprising calcium silicate hydrate; and (c) drying the resulting mixture.

The invention also relates to the hardening accelerator obtainable by this method, to the use thereof, and to building material mixtures which comprise the hardening accelerator.

The invention concerns a process for the preparation of a calcium silicate hydrate and ettringite containing hardening accelerator composition by reaction of a water-soluble calcium compound, silicate compound, aluminum compound and a sulfate compound, wherein the molar ratio of silicon to sulfate is from 2/1 to 30/1 and the reaction of the four compounds being carried out in the presence of an aqueous solution which contains a comb polymer suitable as a plasticizer for hydraulic binders. Also concerned are the use of said accelerators in building material mixtures, the building material mixtures containing said accelerators and a process for the preparation of a sprayable binder composition in which said accelerators are used.

The invention concerns a process for the preparation of a calcium silicate hydrate and ettringite containing hardening accelerator composition by reaction of a water-soluble calcium compound, silicate compound, aluminum compound and a sulfate compound, wherein the molar ratio of silicon to sulfate is from 2/1 to 30/1 and the reaction of the four compounds being carried out in the presence of an aqueous solution which contains a comb polymer suitable as a plasticizer for hydraulic binders. Also concerned are the use of said accelerators in building material mixtures, the building material mixtures containing said accelerators and a process for the preparation of a sprayable binder composition in which said accelerators are used.

The invention relates to a composition comprising 5-50 wt % of calcium silicate hydrate, 10-60 wt % of at least one water-soluble, acid group-containing polymer comprising polyether groups, and 5-40 wt % of at least one polyalkylene glycol ether. Further disclosed is a process for preparing this composition, and cementitious mixtures comprising the composition. A further aspect of the present invention is the use of the composition of the invention in cementitious mixtures for accelerating the development over time of the dispersing action of the acid group-containing polymer after addition of the mixing water and a subsequently accelerated curing of the mixture.

The invention relates to a composition comprising 5-50 wt % of calcium silicate hydrate, 10-60 wt % of at least one water-soluble, acid group-containing polymer comprising polyether groups, and 5-40 wt % of at least one polyalkylene glycol ether. Further disclosed is a process for preparing this composition, and cementitious mixtures comprising the composition. A further aspect of the present invention is the use of the composition of the invention in cementitious mixtures for accelerating the development over time of the dispersing action of the acid group-containing polymer after addition of the mixing water and a subsequently accelerated curing of the mixture.

The invention concerns a process for the for the preparation of a hardening accelerator composition by reaction of a water-soluble calcium compound with a water-soluble silicate compound, the reaction being carried out in the presence of an aqueous solution which contains a plasticizer suitable for hydraulic binders, characterized in that said reaction is being carried out in the presence of apatite and that the molar ratio of calcium to phosphor in the hardening accelerator is from 25/1 to 400/1.

A process for the preparation of a hardening accelerator composition by reaction of a water-soluble calcium compound with a water-soluble silicate compound, said reaction being effected in the present of a water-soluble dispersant having at least one polyalkyleneglycol structural unit with a functional group at one end of the polyalkyleneglycol, being able to interact as an anchor group with the surface of cement particles, the hardening accelerator composition and its use.