The present invention relates to admixtures, especially a dispersant for solid particles, in particular a dispersant for mineral binder compositions, comprising: a) a superplasticizer and b) a copolymer having a polymer backbone and side chains bonded thereto, comprising at least one ionizable monomer unit M1 and at least one side chain-bearing monomer unit M2, wherein the copolymer has a nonrandom distribution of the monomer units M1 and/or the monomer units M2 in a direction along the polymer backbone,
and wherein the superplasticizer and the copolymer differ from a chemical and/or structural point of view.

A method for inerting a swellable clay and/or for reducing or inhibiting adverse effects of swellable clays on the effectiveness of dispersants in mineral binder compositions, includes adding a comb polymer to a mineral binder composition. The comb polymer includes: at least one poly(alkylene oxide) side chain-bearing monomer unit without ionic groups, optionally at least one cationic monomer unit, optionally at least one anionic monomer unit, and optionally, at least one non-ionic monomer unit.

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 relates to a block copolymer for use as a dispersant for mineral binder compositions, containing an alkali activating agent. Said block copolymer comprises at least one first block A and at least one second block B, the first block A containing a monomeric unit M1 and the second block B containing a monomeric unit M2. A proportion of monomeric units M2, if any, in the first block A is less than 25 mol %, in particular less than or equal to 10 mol %, relative to all the monomeric units M1 in the first block A, and a proportion of monomeric units M1, if any, in the second block B is less than 25 mol %, in particular less than or equal to 10 mol %, relative to all the monomeric units M2 in the second block B.

The invention relates to a block copolymer for use as a dispersant for mineral binder compositions, containing an alkali activating agent. Said block copolymer comprises at least one first block A and at least one second block B, the first block A containing a monomeric unit M1 and the second block B containing a monomeric unit M2. A proportion of monomeric units M2, if any, in the first block A is less than 25 mol %, in particular less than or equal to 10 mol %, relative to all the monomeric units M1 in the first block A, and a proportion of monomeric units M1, if any, in the second block B is less than 25 mol %, in particular less than or equal to 10 mol %, relative to all the monomeric units M2 in the second block B.

An admixture for cement, including: A) a comb polymer comprising the following partial structural units or consisting thereof: a) a mole fractions of a partial structural unit S1 of formula (I)

##STR00001## b) b mole fractions of a partial structural unit S2 of formula (II)

##STR00002## where M, R.sup.u, R.sup.v, m and R.sup.1 are as defined in the invention; and B) optionally, alkanol amine.

The admixture for cement can provide remarkable improvement effects, particularly in milling aid effect, water-reducing properties, slump, fluidity and strength, for cements containing inferior or cheap mineral aggregate.

The present invention relates to a copolymer, especially for use as a dispersant for solid particles, in particular for use as dispersant for mineral binder compositions, having a polymer backbone and side chains bonded thereto, comprising at least one ionizable monomer unit M1 and at least one side chain-bearing monomer unit M2, wherein the copolymer has a gradient structure in at least one section A in a direction along the polymer backbone with regard to the ionizable monomer unit M1 and/or with regard to the side chain-bearing monomer unit M2.

A method for producing a dispersant for solid particles, in particular a dispersant for mineral binder compositions. Ionizable monomers m1 and sidechain-carrying monomers m2 are polymerized to a copolymer, polymerization taking place as a living free radical polymerization.

A copolymer as dispersant in a binder composition comprising an alkaline activating agent, wherein the activating agent is especially suitable for activation of a latently hydraulic and/or pozzolanic binder, wherein the copolymer has a polymer backbone and side chains bonded thereto and comprises at least one ionizable monomer unit M1 and at least one side chain-bearing monomer unit M2, and wherein the copolymer has a gradient structure in at least one section A in a direction along the polymer backbone with regard to the ionizable monomer unit M1 and/or with regard to the side chain-bearing monomer unit M2.