FR3152023A1 - New hydraulic binder compositions and hydraulic compositions based on calcined clays - Google Patents

Abstract

New hydraulic binder compositions and hydraulic compositions based on calcined clays The present invention relates to an adjuvanted hydraulic binder composition comprising: - a hydraulic binder composition comprising, relative to the dry mass of the hydraulic binder composition: - from 30% to 95% by mass of clinker, and - from 5% to 70% by mass of activated clay, - from 0% to 60% by mass of calcium carbonate or magnesium carbonate or a mixture of calcium carbonate and magnesium carbonate, preferably limestone, and - from 0% to 10% by mass of calcium sulfate; - a first reducing or high water reducing adjuvant selected from polyalkoxylated polycarboxylate polymers and polyalkoxylated phosphonate polymers, and any of their mixtures, and - a second adjuvant selected from polymers of the following formula (B): in which "X" represents N or O, "R" is selected from H, a C1-C10 alkyl group, a cyclohexyl group, an alkylaryl group and an unsaturated group, "R'" is selected from OH, a C1-C10 alkyl group, a cyclohexyl group, an alkylaryl group, NH2, COOH, a C1-C6 ester or an ammonium group, "Alk" represents a linear or branched C2-C6 alkylene group, and "n" is an integer ranging from 2 to 10,000, preferably from 6 to 250. Figure for abstract: None

Description

New hydraulic binder compositions and hydraulic compositions based on calcined clays

The present invention relates to a calcined clay-based hydraulic binder composition, comprising a specific combination of adjuvants.

The present invention also relates to a hydraulic composition based on calcined clay and comprising said combination of adjuvant.

The present invention further relates to the use of said specific combination of adjuvants as a fluidifier of a hydraulic binder composition or of a hydraulic composition based on calcined clays.

Common cementitious compositions, even those containing mineral additions such as calcined clays, include a significant proportion of clinker. For example, most common cements defined in EN 197-1:2011 “Composition, specifications and conformity criteria for common cements” include at least 65% by weight of clinker, and according to EN 197-5:2021 between 50% and 64% of clinker for CEM II/C-M.

Research is underway to reduce the clinker content of cementitious compositions and hydraulic binder compositions in order to reduce their carbon impact, while maintaining their mechanical and rheological properties. New cementitious compositions and hydraulic binders in which part of the clinker is replaced by activated clays and limestones are beginning to emerge.

One of the obstacles to the development of such compositions is that the replacement of clinker in favor of mineral additions, such as calcined clays, leads formulators to significantly lower the water/binder ratio of hydraulic compositions based on hydraulic binder compositions in order to promote the development of short-term resistance and not impact the durability of the structure. This reduction in the water/binder ratio has the direct consequence of increasing the viscosity of the hydraulic composition.

The intrinsic properties of mineral additives can also be the cause of the increase in the viscosity of the hydraulic composition. It is known that the water demand of mineral additives, and in particular calcined clays, can be higher than usual cements containing high proportions of clinker and this can lead to an increase in the viscosity of the hydraulic composition.

Most of the admixtures known to reduce the viscosity of a hydraulic composition with a usual clinker content are not effective enough to reduce the viscosity of a hydraulic composition with a reduced clinker content, or else need to be introduced at levels too high to be economically viable.

Furthermore, it is often difficult to find adjuvants that can reduce the viscosity of hydraulic compositions without causing significant delays in setting and without impacting their mechanical performance, particularly in the short term.

There is therefore a need for new calcined clay-based hydraulic binder compositions whose resulting hydraulic compositions have low viscosity.

In particular, there is a need for hydraulic binder compositions based on calcined clays, the resulting hydraulic compositions of which have a low viscosity and a low water/binder ratio (to promote the development of short-term resistance and not impact the durability of the structure).

There is therefore a particular need for hydraulic binder compositions based on calcined clays, the resulting hydraulic compositions of which exhibit both low viscosity and high mechanical strengths (for example at 20 hours and 28 days).

The invention therefore relates to an adjuvanted hydraulic binder composition comprising:

- a hydraulic binder composition comprising, relative to the dry mass of the hydraulic binder composition:

- from 30 to 95% by mass of clinker,

- from 5 to 70% by mass of activated clay,

- from 0 to 60% by mass of calcium carbonate or magnesium carbonate or a mixture of calcium carbonate and magnesium carbonate, preferably limestone, and

- from 0 to 10% by mass of calcium sulfate,

- a first reducing or high water reducing adjuvant chosen from polyalkoxylated polycarboxylate polymers and polyalkoxylated phosphonate polymers, and any of their mixtures, and

- a second adjuvant chosen from the polymers of the following formula (B):

in which

- “X” represents N or O,

- “R” is chosen from H, a C1-C10 alkyl group, a cyclohexyl group, an alkylaryl group and an unsaturated group,

- “R'” is chosen from OH, a C1-C10 alkyl group, a cyclohexyl group, an alkylaryl group, NH ₂ , COOH, a C1-C6 ester and an ammonium group,

- “Alk” represents a C2-C6 alkylene group, linear or branched,

- “n” is an integer ranging from 2 to 10000, preferably from 6 to 250.

For the purposes of the application, the term “adjuvanted hydraulic binder composition” means a composition comprising the hydraulic binder composition as defined above and at least the first and second adjuvants (and optionally the additional adjuvants), and the term “hydraulic binder composition” means the hydraulic binder composition (dry) free of adjuvant.

The inventors have surprisingly discovered that the combination of a polymer of formula (B) with a water-reducing or high-reducing adjuvant selected from polyalkoxylated polycarboxylate polymers and polyalkoxylated phosphonate polymers and any of their mixtures makes it possible to enhance the performance of the water-reducing or high-reducing adjuvant. Thus, it is possible to obtain calcined clay-based hydraulic compositions with low viscosity using economically viable amounts of water-reducing or high-reducing adjuvant. This is all the more remarkable since this improvement in viscosity does not result in a drop in mechanical performance.

These results are completely unexpected since the polymer of formula (B) alone has no positive impact on the decrease in viscosity. The inventors have therefore discovered a synergistic effect between the water reducers or high reducers selected from polyalkoxylated polycarboxylate polymers and polyalkoxylated phosphonate polymers and any of their mixtures and the polymers of formula (B).

Hydraulic binder composition

The hydraulic binder composition included in the adjuvanted hydraulic binder composition according to the invention comprises, relative to the dry mass of the hydraulic binder composition:

- from 30 to 95% by mass of clinker,

- from 5 to 70% by mass of activated clay,

- from 0 to 60% by mass of calcium carbonate or magnesium carbonate or a mixture of calcium carbonate and magnesium carbonate, preferably limestone, and

- from 0 to 10% by mass of calcium sulfate.

Preferably, the hydraulic binder composition comprises, relative to the dry mass of the hydraulic binder composition, from 30 to 80% by mass, preferably from 35 to 60% by mass, preferably from 35 to 50% by mass of clinker.

Preferably, the hydraulic binder composition comprises, relative to the dry mass of the hydraulic binder composition, from 10 to 60% by mass, preferably from 15 to 50% by mass, preferably from 15 to 40% by mass of activated clay.

Such a hydraulic binder composition is not usual in that its proportion of clinker is low and its proportion of activated clay is high. The hydraulic binder composition is in particular of type LC ³ (acronym for "Limestone Calcined Clay Cement" in English), and/or it can be a cement of type CEM II/CM (Q -L) or CEM II/CM (Q -LL) of the standard EN 197-5:2021 .

The clinker is in particular Portland clinker, preferably Portland clinker as defined in the book “Cement Chemistry”. Harry F. W. Taylor. Edition, 2., Academic Press, 1990).

By "activated clay" we mean any type of clay modified by heat treatment and their mixtures. This treatment corresponds to calcination, which is most often carried out in a rotary kiln, but also by a "flash" calcination process, or any other process leading to dehydroxylation of the clay. The clay is introduced in the form of balls and calcined at temperatures allowing their dehydroxylation (loss of one or more hydroxyl groups (OH) in the form of water (H ₂ O) from a clay).

The activated clay according to the invention may in particular comprise a mixture of several activated clays.

Preferably, the activated clay is a kaolinic (also called kaolinitic) clay that has been activated. By “kaolinic clay” is meant a clay that includes kaolinite. An “activated kaolinic clay” is a kaolinic clay, at least a portion of the kaolinite of which has been dehydroxylated to metakaolin. For example, upon heating the clay mineral kaolinite from 300°C to 600°C, water is lost according to the following reaction.

Al ₂ Si ₂ O ₅ (OH) ₄ → AI ₂ Si ₂ O ₇ + 2 H ₂ O

Thus, a kaolin clay that has been activated includes, or even consists of, metakaolin. Metakaolin is very reactive in the presence of water and portlandite (calcium hydroxide resulting from the hydration of calcium silicates in cements) to form hydrated phases, in particular hydrated calcium aluminosilicate (C-A-S-H) and strätlingite.

For the purposes of the application, the activated kaolin clay may comprise residual kaolinite (which has not been dehydroxylated during activation) in a content, as measured by thermogravimetric analysis (TGA), typically by raising the temperature between 30°C and 900°C, with, for example, a heating rate of 10°C/min, which makes it possible to quantify the loss of mass corresponding to the water released by the clay. This residual kaolinite content is generally less than or equal to 50% by mass, typically less than or equal to 40% by mass, in particular less than or equal to 30% by mass, preferably less than or equal to 20% by mass, particularly preferably less than or equal to 10% by mass, relative to the mass of the activated clay. The activated kaolin clay may be free of kaolinite (the dehydroxylation has then been complete).

Dehydroxylation can be carried out by heat treatment.

The heat treatment is a calcination, generally at a temperature between 400°C and 700°C (dehydroxylation temperature). We then speak of kaolin clay having been calcined.

Calcination is most often done in a rotary kiln into which the clay is introduced. The kaolin is transformed at least partially into an amorphous and reactive phase, with a strong pozzolanic power, called metakaolin. The calcined clay is then crushed. Metakaolin can also be produced by a "Flash" calcination process where the clay is crushed and the fine particles are calcined in a few seconds in a kiln.

Preferably, within the hydraulic binder composition, the mass ratio of the mass of clinker relative to the mass of activated clay ranges from 0.3 to 5, preferably from 0.8 to 4, preferably from 1 to 3.5, preferably from 1.5 to 3, preferably from 2 to 2.5.

Preferably, the hydraulic binder composition comprises from 10% to 60% by mass, preferably from 30% to 60% by mass, preferably from 35% to 55% by mass, preferably from 40% to 50% by mass of calcium carbonate or magnesium carbonate or a mixture of calcium carbonate and magnesium carbonate, preferably limestone relative to the dry mass of the hydraulic binder composition. Limestone is preferably as defined in EN 197-1:2011 paragraph 5.2.6.

Preferably, within the hydraulic binder composition, the mass ratio of the mass of calcined clay relative to the mass of calcium carbonate or magnesium carbonate or a mixture of calcium carbonate and magnesium carbonate, preferably limestone, ranges from 0.1 to 6, preferably from 0.2 to 4, preferably 0.25 to 2, preferably 0.3 to 0.9.

Preferably, within the hydraulic binder composition, the mass ratio of the mass of clinker relative to the mass of calcium carbonate or magnesium carbonate or a mixture of calcium carbonate and magnesium carbonate, preferably limestone, ranges from 0.2 to 7, preferably from 0.4 to 5, preferably from 0.5 to 3, preferably 0.6 to 1.

Preferably, the hydraulic binder composition may also comprise from 0 to 5% by mass of calcium sulfate to regulate setting, preferably from 1% to 5% by mass of calcium sulfate, the proportions being by mass relative to the dry mass of the hydraulic binder composition.

Calcium sulfate can be gypsum (calcium sulfate dihydrate, CaSO ₄ ·2H ₂ O), hemihydrate (CaSO4 ·1/2H ₂ O), or anhydrite (anhydrous calcium sulfate, CaSO ₄ ) or any mixture of these.

The hydraulic binder composition may comprise one or more additives known to those skilled in the art, for example an anti-foam additive, and/or an air-entraining additive, additives for regulating setting and strength increase, such as accelerating or retarding agents. The hydraulic binder composition may further comprise a grinding agent which may or may not be an alkanolamine.

Preferably the grinding agent composition comprises a grinding agent as described in WO2020074633 or WO2021204942.

Particular mention may be made of triisopropanolamine (TIPA), diethanolisopropanolamine (DEIPA), ethanoldiisopropanolamine (EDIPA) and methyldiethanolamine (MDEA), diisopropanolamine (DIPA), and N,N,N′,N′-tetrakis(2-hydroxyethyl)ethylenediamine (THEED).

First adjuvant

The first adjuvant according to the invention is chosen from polyalkoxylated polycarboxylate polymers and polyalkoxylated phosphonate polymers, and any of their mixtures.

Preferably, the polyalkoxylated polycarboxylate polymers comprise units of the following formulas (I) and (II):

in which

- “R2” and “R3” independently represent hydrogen or methyl,

- “M” independently represents H ⁺ or a cation of valence v chosen from an alkali metal cation, an alkaline-earth metal cation, a bi- or trivalent metal cation, an ammonium cation or an organic ammonium cation,

- when “M” represents H, “v” represents 1, and when “M” represents a cation, “v” is the valence of the cation M,

- “R7” and “R8” independently represent hydrogen, methyl or a group of formula –COO(M) _{1/ v} with M and v as defined above,

- “m” represents 0, 1 or 2,

- “p” represents 0 or 1,

- “X” is Y or N, and

- “R1” represents a C1-C20 alkyl group, a cycloalkyl group, an alkylaryl group, or -[O-Alkyl] _z -OR6, wherein the “Alkyl” of each O-Alkyl unit of the group –[O-Alkyl] _z - independently represents a linear or branched alkylene comprising from 2 to 4 carbon atoms, and “R6” represents H, a C1-C20 alkyl group, a cyclohexyl group or an alkylaryl group, and “z” is an integer ranging from 2 to 250,

- “a” is a number ranging from 0.05 to 0.95, “a” being the mole fraction of units of formula (I) in the polymer, and

- “b” is a number ranging from 0.05 to 0.95, “b” being the mole fraction of units of formula (II) in the polymer.

Preferably, the polyalkoxylated polycarboxylate polymers have a comb structure.

The following embodiments for formulas (I) and (II) of the units of the polycarboxylate polyalkoxylated polymer can be considered independently or combined with each other:

- “R2” represents H, and/or

- “R7” represents H, and/or

- “R3” independently represents hydrogen or methyl, and/or

- “R8” independently represents hydrogen or methyl, and/or

- either p = 0 and m = 1 or 2, preferably 1, or p = 1 and m = 0, and/or

- X = O, and/or

- R1 = -[O-Alkyl] _z -O-R6, with preferably:

- “Alkyl” represents -CH ₂ -CH ₂ -, -CH ₂ -CH ₂ -CH ₂ -, -CH ₂ -CH _{2 -CH 2 -CH 2} -, -CH ₂ -CHMe-, -CHMe-CH ₂ -, and/or

- at least 80% of the Alkyls of the group –[O-Alkyl] _z - represent -CH ₂ -CH ₂ -, or even all the Alkyls of the group –[O-Alkyl] _z - represent -CH ₂ -CH ₂ -, and/or

- “z” represents an integer from 5 to 200, in particular from 10 to 100, preferably from 25 to 75, and/or

- “R6” represents H or Me,

and/or

- "M" represents H or a monovalent or bivalent cation, "m" then representing 1 or 2, the monovalent cation preferably being chosen from an ammonium salt NH ₄ ⁺ , a primary, secondary, tertiary or quaternary ammonium cation and a cation of an alkali metal, such as a sodium, lithium or potassium ion, and the bivalent cation preferably being a cation of an alkaline earth metal, such as a magnesium or calcium ion, and/or

- “a” is a number from 0.20 to 0.90, preferably “a” is a number from 0.40 to 0.85, and/or

- “b” is a number from 0.10 to 0.80, preferably “b” is a number from 0.15 to 0.60.

Preferably, in the units of formula (I):

- “R2” represents H,

- “R3” independently represents hydrogen or methyl,

- “M” is sodium or calcium,

- “a” is a number ranging from 0.20 to 0.90, preferably “a” is a number ranging from 0.40 to 0.85.

Preferably, in the units of formula (II):

- “R7” represents H,

- “R8” independently represents hydrogen or methyl,

- X = O,

- R1 = -[O-Alkyl] _z -O-R6, with preferably:

- “Alkyl” represents -CH ₂ -CH ₂ -, -CH ₂ -CH ₂ -CH ₂ -, -CH ₂ -CH _{2 -CH 2 -CH 2} -, -CH ₂ -CHMe-, -CHMe-CH ₂ -, and/or

- at least 80% of the “Alkyl” of the group –[O-Alkyl] _z - represent -CH ₂ -CH ₂ -, or even all the “Alkyl” of the group –[O-Alkyl] _z - represent -CH ₂ -CH ₂ -, and/or

- “z” represents an integer ranging from 5 to 200, in particular from 10 to 100, preferably from 25 to 75, and/or

- “R6” represents H or Me,

- either p = 0 and m = 1 or 2, preferably 1, or p = 1 and m = 0, and

- “b” is a number ranging from 0.10 to 0.80, preferably “b” is a number ranging from 0.15 to 0.60.

According to one embodiment, the units of formula (II) of the polyalkoxylated polycarboxylate polymers are such that p = 0 and m = 1 or 2, preferably 1.

Preferably, according to this embodiment:

- “R2” represents H, and/or

- “R7” represents H, and/or

- “R3” independently represents hydrogen or methyl, preferably R3 = H and/or

- “R8” independently represents hydrogen or methyl, preferably R3 = Me, and/or

- X = O, and/or

- R1 = -[O-Alkyl] _z -O-R6, with preferably:

- “Alkyl” represents -CH ₂ -CH ₂ -, -CH ₂ -CH ₂ -CH ₂ -, -CH ₂ -CH _{2 -CH 2 -CH 2} -, -CH ₂ -CHMe-, -CHMe-CH ₂ -, and/or

- at least 80% of the Alkyls of the group –[O-Alkyl] _z - represent -CH ₂ -CH ₂ -, or even all the Alkyls of the group –[O-Alkyl] _z - represent -CH ₂ -CH ₂ -, and/or

- “z” represents an integer from 5 to 200, in particular from 10 to 100, preferably from 25 to 75, and/or

- “R6” represents H or Me, preferably “R6 » represents H,

and/or

- "M" represents H or a monovalent or bivalent cation, "m" then representing 1 or 2, the monovalent cation preferably being chosen from an ammonium salt NH ₄ ⁺ , a primary, secondary, tertiary or quaternary ammonium cation and a cation of an alkali metal, such as a sodium, lithium or potassium ion, and the bivalent cation preferably being a cation of an alkaline earth metal, such as a magnesium or calcium ion, and/or

- “a” is a number from 0.30 to 0.95, preferably a is a number from 0.50 to 0.90, and/or

- “b” is a number from 0.05 to 0.70, preferably b is a number from 0.10 to 0.50.

Preferably,

- “R2” represents H,

- “R3” independently represents hydrogen or methyl,

- “M” is sodium or calcium,

- “R7” represents H,

- “R8” independently represents hydrogen or methyl,

- X = O,

- R1 = -[O-Alkyl] _z -O-R6, with preferably:

- “Alkyl” represents -CH ₂ -CH ₂ -, -CH ₂ -CH ₂ -CH ₂ -, -CH ₂ -CH _{2 -CH 2 -CH 2} -, -CH ₂ -CHMe-, -CHMe-CH ₂ -, and/or

- at least 80% of the “Alkyl” of the group –[O-Alkyl] _z - represent -CH ₂ -CH ₂ -, or even all the Alkyl of the group –[O-Alkyl] _z - represent -CH ₂ -CH ₂ -, and/or

- “z” represents an integer from 5 to 200, in particular from 10 to 100, preferably from 25 to 75, and/or

- “R6” represents H or Me, preferably “R6” represents H.

- “a” is a number from 0.30 to 0.95, preferably “a” is a number from 0.50 to 0.90, and

- “b” is a number from 0.05 to 0.70, preferably “b” is a number from 0.10 to 0.50.

According to another embodiment, the units of formula (II) of the polyalkoxylated polycarboxylate polymers are such that p = 1 and m = 0.

Preferably, according to this embodiment:

- “R2” represents H, and/or

- “R7” represents H, and/or

- “R3” independently represents hydrogen or methyl, and/or

- “R8” independently represents hydrogen or methyl, and/or

- X = O, and/or

- R1 = -[O-Alkyl] _z -O-R6, with preferably:

- “Alkyl” represents -CH ₂ -CH ₂ -, -CH ₂ -CH ₂ -CH ₂ -, -CH ₂ -CH _{2 -CH 2 -CH 2} -, -CH ₂ -CHMe-, -CHMe-CH ₂ -, and/or

- at least 80% of the Alkyls of the group –[O-Alkyl] _z - represent -CH ₂ -CH ₂ -, or even all the Alkyls of the group –[O-Alkyl] _z - represent -CH ₂ -CH ₂ -, and/or

- “z” represents an integer from 5 to 200, in particular from 10 to 100, preferably from 15 to 50, and/or

- “R6” represents H or Me, preferably R6 represents Me,

and/or

- "M" represents H or a monovalent or bivalent cation, "m" then representing 1 or 2, the monovalent cation preferably being chosen from an ammonium salt NH ₄ ⁺ , a primary, secondary, tertiary or quaternary ammonium cation and a cation of an alkali metal, such as a sodium, lithium or potassium ion, and the bivalent cation preferably being a cation of an alkaline earth metal, such as a magnesium or calcium ion, and/or

- “a” is a number from 0.30 to 0.80, preferably “a” is a number from 0.40 to 0.70, and/or

- “b” is a number from 0.20 to 0.70, preferably “b” is a number from 0.30 to 0.60.

Preferably,

- “R2” represents H,

- “R3” independently represents hydrogen or methyl,

- “M” is sodium or calcium,

- “R7” represents H,

- “R8” independently represents hydrogen or methyl,

- X = O,

- R1 = -[O-Alkyl] _z -O-R6, with preferably:

- “Alkyl” represents -CH ₂ -CH ₂ -, -CH ₂ -CH ₂ -CH ₂ -, -CH ₂ -CH _{2 -CH 2 -CH 2} -, -CH ₂ -CHMe-, -CHMe-CH ₂ -, and/or

- at least 80% of the Alkyls of the group –[O-Alkyl] _z - represent -CH ₂ -CH ₂ -, or even all the Alkyls of the group –[O-Alkyl] _z - represent -CH ₂ -CH ₂ -, and/or

- “z” represents an integer from 5 to 200, in particular from 10 to 100, preferably from 15 to 50, and/or

- “R6” represents H or Me, preferably “R6” represents Me.

- “a” is a number from 0.30 to 0.80, preferably “a” is a number from 0.40 to 0.70, and

- “b” is a number from 0.20 to 0.70, preferably “b” is a number from 0.30 to 0.60.

Preferably, according to this embodiment, the units of formula (II) are present in the form of two distinct subunits (IIb) and (IIc). The two subunits (IIb) and (IIc) are of formula (II), according to any embodiment of the units of formula (II) defined above, but are different from each other.

Preferably, according to this embodiment, "a" is a number from 0.30 to 0.80, preferably from 0.40 to 0.70, "a" being the molar fraction of units of formula (I) in the polymer, "b'" is a number from 0.10 to 0.35, preferably from 0.15 to 0.30, "b'" being the molar fraction of units (IIb) in the polymer, and "c" is a number from 0.10 to 0.35, preferably from 0.15 to 0.30, "c" being the molar fraction of units (IIc) in the polymer.

Preferably, in units (IIb):

- “R7” represents H,

- “R8” independently represents hydrogen or methyl,

- X = O,

- R1 = -[O-Alkyl] _z -O-R6, with preferably:

- “Alkyl” represents -CH ₂ -CH ₂ -, -CH ₂ -CH ₂ -CH ₂ -, -CH ₂ -CH _{2 -CH 2 -CH 2} -, -CH ₂ -CHMe-, -CHMe-CH ₂ -, and/or

- at least 80% of the Alkyls of the group –[O-Alkyl] _z - represent -CH ₂ -CH ₂ -, or even all the Alkyls of the group –[O-Alkyl] _z - represent -CH ₂ -CH ₂ -, and/or

- “z” represents an integer from 5 to 200, in particular from 10 to 100, preferably from 15 to 50, and/or

- “R6” represents H or Me, preferably “R6” represents Me.

- “b’” is a number from 0.10 to 0.35, preferably from 0.15 to 0.30, “b’” being the molar fraction of units of formula (IIb) in the polymer.

Preferably, in units (IIc):

- “R7” represents H,

- “R8” independently represents hydrogen or methyl, preferably R8 = Me,

- X = O,

- R1 = -[O-Alkyl] _z -O-R6, with preferably:

- “Alkyl” represents -CH ₂ -CH ₂ -, -CH ₂ -CH ₂ -CH ₂ -, -CH ₂ -CH _{2 -CH 2 -CH 2} -, -CH ₂ -CHMe-, -CHMe-CH ₂ -, and/or

- at least 80% of the Alkyls of the group –[O-Alkyl] _z - represent -CH ₂ -CH ₂ -, or even all the Alkyls of the group –[O-Alkyl] _z - represent -CH ₂ -CH ₂ -, and/or

- “z” represents an integer from 5 to 200, in particular from 10 to 100, preferably from 15 to 30, and/or

- “R6” represents H or Me, preferably “R6” represents Me.

- “c” is a number from 0.10 to 0.35, preferably from 0.15 to 0.30, “b’” being the molar fraction of units of formula (IIb) in the polymer.

Preferably, the polyalkoxylated phosphonate polymers are of the following formula (III):

in which

“R5” is a hydrogen atom or a monovalent hydrocarbon group having from 1 to 18 carbon atoms and optionally one or more heteroatoms;

the “Ri” are similar or different to each other and represent an alkylene such as ethylene, propylene, butylene, amylene, octylene or cyclohexene, or an arylene such as styrene or methylstyrene, the “Ri” optionally containing one or more heteroatoms;

“Q” is a hydrocarbon group having from 2 to 18 carbon atoms and optionally one or more heteroatoms;

“A” is an alkylene group having 1 to 5 carbon atoms;

the “Rj” are similar or different from each other and can be chosen from:

- the group A-PO ₃ H ₂ , A having the aforementioned meaning,

- an alkyl group comprising from 1 to 18 carbon atoms and which may carry [R5-O(Ri-O) _m ] groups, R5 and Ri having the aforementioned meanings,

"m" is a number greater than or equal to 0,

"r" is the number of groups [R5-O(Ri-O) _m ] carried by the set of Rj,

"q" is the number of groups [R5-O(Ri-O) _m ] carried by Q, the sum

"r+q" is between 1 and 10,

"y" is an integer between 1 and 3,

“Q”, “N” and “Rj” may together form one or more cycles, this or these cycles may further contain one or more other heteroatoms.

Particularly preferably, the polyalkoxylated phosphonates consist of a water-soluble or water-dispersible organic compound comprising at least one amino-di-(alkylene-phosphonic) group and at least one polyoxyalkylated chain or at least one of its salts.

Preferably, the polyalkoxylated phosphonate is a compound of formula (III) in which:

“R5” is a hydrogen atom or a monovalent hydrocarbon group, saturated or unsaturated, containing from 1 to 8 carbon atoms and optionally one or more heteroatoms;

the “Ri” represent ethylene or propylene or a mixture of ethylene or propylene, preferably from 60% to 100% of the “Ri” are ethylene groups;

“Q” is a hydrocarbon group having from 2 to 8 carbon atoms and, optionally, one or more heteroatoms;

“A” is the methylene group;

each of the “Rj” represents the CH group₂-PO₃H₂ ;

"m" is an integer between 10 and 250;

"q" is an integer equal to 1 or 2;

"y" is an integer equal to 1 or 2, preferably equal to 1.

In particular, the polyalkoxylated phosphonate may be a polyalkoxylated phosphonate of formula (III) in which “R5” is a methyl group, the “Ri” are ethylene and propylene groups, “m” being between 30 and 50, “r+q” is 1, “Q” is a propylene group, “A” is a methylene group, “y” is 1 and “Rj” corresponds to the CH ₂ -PO ₃ H ₂ group.

Preferably, the first adjuvant comprises a mixture of at least two polymers chosen from polyalkoxylated polycarboxylate polymers and polyalkoxylated phosphonate polymers, the polymers each being independently according to any one of the embodiments defined above.

The first adjuvant may therefore, for example, comprise a mixture of at least two polyalkoxylated polycarboxylate polymers, or a mixture of at least two polyalkoxylated phosphonate polymers, or a mixture of at least one polyalkoxylated polycarboxylate polymer and at least one polyalkoxylated phosphonate polymer, the polymers each being independently according to any one of the embodiments defined above.

Preferably, the first adjuvant is chosen from:

- a polyalkoxylated polycarboxylate polymer comprising units of formulae (I) and (II) as defined above, in which p = 0 and m = 1 or 2, preferably 1,

- a polyalkoxylated polycarboxylate polymer comprising units of formulae (I) and (II) as defined above, in which p = 1 and m = 0,

- a polyalkoxylated phosphonate polymer, as defined above,

- and any mixture thereof,

preferably the first adjuvant comprises a mixture of at least two polymers chosen from:

- a polyalkoxylated polycarboxylate polymer comprising units of formulae (I) and (II) as defined above, in which p = 0 and m = 1 or 2, preferably 1,

- a polyalkoxylated polycarboxylate polymer comprising units of formulae (I) and (II) as defined above in which p = 1 and m = 0, and

- a polyalkoxylated phosphonate polymer, as defined above.

The first adjuvant can therefore, for example, include:

- a mixture of at least two polyalkoxylated polycarboxylate polymers comprising units of formulae (I) and (II) as defined above, in which p = 0 and m = 1 or 2, preferably 1, or

- a mixture of at least two polyalkoxylated polycarboxylate polymers comprising units of formulae (I) and (II) as defined above in which p = 1 and m = 0, or

- a mixture of at least two polyalkoxylated phosphonate polymers, as defined above, or

- a mixture of at least one polyalkoxylated polycarboxylate polymer comprising units of formulae (I) and (II) as defined above, in which p = 0 and m = 1 or 2, preferably 1 and of at least one polyalkoxylated polycarboxylate polymer comprising units of formulae (I) and (II) as defined above in which p = 1 and m = 0, or

- a mixture of at least one polyalkoxylated polycarboxylate polymer comprising units of formulae (I) and (II) as defined above, in which p = 0 and m = 1 or 2, preferably 1, and of at least one polyalkoxylated phosphonate polymer as defined above, or

- a mixture of at least one polyalkoxylated polycarboxylate polymer comprising units of formulae (I) and (II) as defined above in which p = 1 and m = 0 and of at least one polyalkoxylated phosphonate polymer as defined above.

The polymers are each independently according to any one of the embodiments defined above. The polyalkoxylated polycarboxylate polymers are in particular according to any variant above corresponding, respectively, to the embodiment in which p = 1 and m = 0 or in which p = 0 and m = 1 or 2.

Advantageously, the first adjuvant is chosen from:

- a polyalkoxylated phosphonate polymer according to any one of the embodiments defined above,

- a mixture of a polyalkoxylated phosphonate polymer according to any one of the embodiments defined above and of a polyalkoxylated polycarboxylate polymer comprising units of formulae (I) and (II) as defined above in which p = 1 and m = 0, and

- a mixture of a polycarboxylate polyalkoxylated polymer polymer comprising units of formulae (I) and (II) as defined above in which p = 1 and m = 0, and of a polycarboxylate polyalkoxylated polymer polymer comprising units of formulae (I) and (II) as defined above in which p = 0 and m = 1 or 2, preferably 1.

The polyalkoxylated polycarboxylate polymers are in particular according to any variant above corresponding, respectively, to the embodiment in which p = 1 and m = 0 or in which p = 0 and m = 1 or 2.

Preferably, the total content of first adjuvant represents from 0.05% to 1.00% by mass, preferably from 0.10% to 0.80% by mass, preferably from 0.20% to 0.60% by mass, preferably from 0.25% to 0.50% by mass, preferably from 0.30% to 0.45% by mass, of the dry mass of the hydraulic binder composition.

Second adjuvant

The second adjuvant according to the invention is a polymer of the following formula (B):

in which

“X” representing N or O, preferably X = O,

“R” is selected from H, a C1-C10 alkyl group, a cyclohexyl group, an alkylaryl group and an unsaturated group,

“R'” is selected from OH, a C1-C10 alkyl group, a cyclohexyl group, an alkylaryl group, NH ₂ , COOH, a C1-C6 ester or an ammonium group,

“Alk” represents a C2-C6, preferably C2-C4, linear or branched alkylene group or mixtures thereof, and

“n” is an integer ranging from 2 to 10000, preferably 6 to 250.

By unsaturated group is meant any hydrocarbon group comprising a carbon-carbon double bond at the end of the chain, preferably a group of formula –C(R _p )=C(R _u )(R _v ) or –CH ₂ –C(R _p )=CH ₂ , with “R _u ” “R _v ” and “R _{p ”} being chosen from H and a hydrocarbon group comprising from 1 to 10 carbon atoms, linear, branched or cyclic, saturated or unsaturated, preferably linear or branched, saturated or unsaturated. These may be, for example, methylallyl, allyl, vinyl or isoprenyl groups.

Preferably:

- “R” is chosen from H, a C1-C10 alkyl group, and an unsaturated group of formula –CH ₂ –C(R _p )=CH ₂ as defined above, and/or

- R’ = OH.

Preferably, “Alk” is –CH ₂ -CH ₂ –.

Preferably, the second adjuvant is chosen from polyethylene glycols (PEG), polyethylene glycol monomethyl ether (MPEG) and polyethylene glycol monomethyl ether (HPEG) comprising from 2 to 10,000, preferably from 6 to 250, [O-CH ₂ -CH ₂ ] units, and any of their mixtures.

Preferably, the content of second adjuvant represents from 0.01% to 1.00% by mass, preferably from 0.02% to 0.80% by mass, preferably from 0.05% to 0.50% by mass, preferably from 0.06% to 0.30% by mass, preferably from 0.07% to 0.20% by mass, of the dry mass of the hydraulic binder composition.

Composition of adjuvanted hydraulic binder

Other adjuvants may be used in the context of the present invention in addition to the first and second adjuvants mentioned above. These adjuvants may be chosen by a person skilled in the art from the adjuvants typical of hydraulic binder compositions and hydraulic compositions. Mention may in particular be made of water-reducing and high-water-reducing adjuvants, surfactants, carboxylic acids or their salts such as acetic, adipic, gluconic, oxalic, citric, maleic, lactic, tartaric, malonic acids and mixtures thereof, anti-foam additives, air-entraining additives and/or grinding agents (including ethylene glycol oligomers or propylene glycol oligomers or mixtures thereof) and/or several solvents such as water, setting retarders, hardening and setting accelerators such as glycerols, formic acid, calcium salts (for example calcium chloride, calcium thiocyanate, calcium nitrite, calcium formate and calcium nitrate), lithium salts, aluminium salts, magnesium salts, sodium salts, alkanolamines, and mixtures thereof, alkali or alkaline earth metal or aluminium salts, inorganic nanoparticles, for example silica or alumina nanoparticles, calcium carbonate nanoparticles, calcium hydrosilicate (CHS) nanoparticles, and mixtures thereof.

Preferably, the adjuvanted hydraulic binder composition further comprises a setting retarder.

In the context of this application, the term "setting retarder" is understood to mean a compound having the effect of delaying the setting of the hydraulic binder composition, i.e. of delaying or inhibiting the phenomena linked to this setting such as hydration phenomena, thereby inducing a later hardening of the hydraulic binder composition. Generally, a setting retarder delays the setting time of a hydraulic binder composition into which it has been introduced at a dosage of at most 5% by dry mass relative to the mass of the clinker, the setting time being measured according to the EN 480-2:2006 test. Preferably, the setting time is delayed by at least 30 minutes relative to a control hydraulic binder composition.

The setting retardant is chosen in particular from:

- a carboxylic or hydroxycarboxylic acid in neutral form or a salt thereof, those having a pK _A of 2 to 5 being preferred. The carboxylic acid being chosen in particular from acetic acid, gluconic acid, citric acid, tartaric acid, malic acid or a mixture thereof,

- a phosphonic acid in neutral form or a salt thereof, in particular chosen from those comprising a group –N[-(CH ₂ )-PO(OH) ₂ ] ₂ or a group >C[-PO(OH) ₂ ] ₂ , preferably chosen from amino tri methylene phosphonic acid (ATMP), ethylene diamine tetra methylene phosphonic acid (EDTMP), 1-hydroxyethylidene -1,1,-diphosphonic acid (HEDP), and their salts, in particular sodium salts.

- a sugar, in particular chosen from glucose, gluconic acid in neutral form or a salt thereof or in lactone form, dextrose, fructose, galactose, sucrose, maltose, lactose and mannose and their mixtures,

- a phosphate, in particular chosen from sodium tripolyphosphate and tetrapotassium pyrophosphate and their mixtures, and

- any of their mixtures.

The salt of the carboxylic acid is preferably an alkali metal salt, such as sodium, lithium or potassium, an alkaline earth metal salt, such as a magnesium or calcium salt or an ammonium salt NH ₄ ⁺ or primary, secondary, tertiary or quaternary ammonium cation.

Preferably, the adjuvanted hydraulic binder composition further comprises a third adjuvant chosen from water reducers or high water reducers and different from the first adjuvant. The third adjuvant is preferably chosen from:

- Sulfonated salts of naphthalene and formaldehyde polycondensates, commonly called polynaphthalene sulfonates or naphthalene-based superplasticizers;

- Sulfonated salts of polycondensates of melamine and formaldehyde, commonly called polymelamine sulfonates or melamine-based superplasticizers;

- Lignin derivatives such as lignosulfonate salts;

- Sodium gluconate and sodium glucoheptonate;

- Polyacrylates;

- Polyaryl ethers (PAE).

Preferably, the third adjuvant is chosen from lignin derivatives such as lignosulfonate salts, sodium gluconate and sodium glucoheptonate.

According to one embodiment, the adjuvanted hydraulic binder composition further comprises an addition product of the alkoxylated glycol alkyl ether type of formula (C) R''O(AO) _x H, in which:

- “R” represents a hydrogen atom H or an alkyl group, linear or branched, comprising from 1 to 22 carbon atoms, or a cycloalkyl comprising from 5 to 7 carbon atoms,

- “A” represents an alkylene, linear or branched, comprising from 1 to 4 carbon atoms, and

- “x” is an integer from 1 to 70.

Preferably, in the compound of formula (C), R’’ = a linear alkyl group comprising 8 to 18 carbon atoms.

Preferably, in the compound of formula (C), "A" is an ethylene or propylene group, preferably ethylene.

Preferably, in the compound of formula (C), “x” is an integer from 1 to 15.

Preferably, the alkoxylated glycol alkyl ether adduct is an ethoxylated fatty alcohol, such that, in formula (C), R'' = a linear alkyl group comprising 8 to 18 carbon atoms, "A" is ethylene and "n" between 5 and 15.

According to one embodiment, the adjuvanted hydraulic binder composition further comprises an addition product of the type of phosphate esters of ethoxylated fatty alcohols with a linear alkyl group comprising between 8 and 18 carbon atoms and a degree of ethoxylation of between 1 and 15.

The additional presence of a setting retarder and/or a third adjuvant as defined above advantageously makes it possible to further improve (reduce) the viscosity of the hydraulic compositions.

The adjuvanted hydraulic binder composition may further comprise an air entrainer. Preferably, the air entrainers are chosen from the alkoxylated glycol alkyl ether type addition products of formula (C) defined above.

Hydraulic composition

The invention also relates to a hydraulic composition comprising the adjuvanted hydraulic binder composition according to the invention (according to any embodiment described above), water, optionally an aggregate and optionally a mineral addition.

The invention therefore also relates to a hydraulic composition comprising:

- a hydraulic binder composition comprising, relative to the total dry mass of the hydraulic binder composition:

- from 30% to 95% by mass of clinker,

- from 5% to 70% by mass of activated clay,

- from 0% to 60% by mass of calcium carbonate or magnesium carbonate or a mixture of calcium carbonate and magnesium carbonate, preferably limestone, and

- from 0% to 10% by mass of calcium sulfate;

- a first reducing or high reducing water-reducing adjuvant defined according to any one of the embodiments defined above for the adjuvanted hydraulic binder composition,

- a second adjuvant (B) defined according to any one of the embodiments defined above for the adjuvanted hydraulic binder composition,

- water,

- possibly a setting retarder as described above for the adjuvanted hydraulic binder composition

- optionally a third adjuvant, preferably chosen from lignin derivatives such as lignosulfonate salts, sodium gluconate and sodium glucoheptonate, as described above for the adjuvanted hydraulic binder composition,

- possibly an air entrainer as described above for the adjuvanted hydraulic binder composition,

- possibly a setting or hardening accelerator as described above for the adjuvanted hydraulic binder composition,

- possibly an aggregate, and

- possibly a mineral addition.

The hydraulic composition is preferably a composition of concrete, mortar or screed.

By "aggregates" we mean a set of mineral grains with an average diameter of between 0 and 125 mm. Depending on their diameter, aggregates are classified into one of the following six families: fillers, sands, gravels, gravels and ballast (standards EN 12620 and EN 13242+A1). The most commonly used aggregates are:

- fillers, which have a diameter of less than 2 mm and for which at least 85% of the aggregates have a diameter of less than 1.25 mm and at least 70% of the aggregates have a diameter of less than 0.063 mm,

- sands with a diameter between 0 and 6.3 mm,

- bass with a diameter greater than 6.3 mm,

- gravel with a diameter between 2 mm and 63 mm.

Sands are therefore included in the definition of aggregate according to the invention.

The fillers can be of limestone or dolomitic origin.

The term "mineral additions" means slags (as defined in EN 197-1:2011 paragraph 5.2.2 and EN 15167-1:2006), steel slags, pozzolanic materials (as defined in EN 197-1:2011 paragraph 5.2.3), fly ash (as defined in EN 197-1:2011 paragraph 5.2.4), calcined shale (as defined in EN 197-1:2011 paragraph 5.2.5), or silica fumes (as defined in EN 197-1:2011 paragraph 5.2.7 or EN 197-5 paragraph 5), limestones or mixtures thereof.

The present invention also relates to the use of the combination of a first adjuvant and a second adjuvant defined according to any one of the embodiments above, as a fluidifier for a hydraulic composition comprising a hydraulic binder composition as defined in the present description, water, optionally an aggregate and optionally a mineral addition.

The present invention therefore also relates to a method for reducing the viscosity of a hydraulic composition or for making it more fluid, and comprising:

- a hydraulic binder composition comprising, relative to the dry mass of the hydraulic binder composition:

- from 30% to 95% by mass of clinker, and

- from 5% to 70% by mass of activated clay,

- from 0% to 60% by mass of calcium carbonate or magnesium carbonate or a mixture of calcium carbonate and magnesium carbonate, preferably limestone, and

- from 0% to 10% by mass of calcium sulfate;

- water,

- possibly an aggregate, and

- possibly a mineral addition,

comprising the addition of a first adjuvant and a second adjuvant defined according to any one of the embodiments above to the hydraulic composition.

This reduction in viscosity (or improvement in fluidity) is preferably long-term, namely over a period greater than or equal to 90 minutes, in particular greater than 120 minutes, or even greater than 240 minutes.

The invention further relates to a method for preparing a hydraulic composition according to the invention, comprising a step of adding, simultaneously or in sequence, a first adjuvant and a second adjuvant as defined according to the invention, in a hydraulic composition comprising:

- a hydraulic binder composition comprising, relative to the dry mass of the hydraulic binder composition:

- from 30% to 95% by mass of clinker,

- from 5% to 70% by mass of activated clay,

- from 0% to 60% by mass of calcium carbonate or magnesium carbonate or a mixture of calcium carbonate and magnesium carbonate, preferably limestone, and

- from 0% to 10% by mass of calcium sulfate; and

- water.

Simultaneous addition means that the first adjuvant and the second adjuvant are added at the same time and in one go to the hydraulic composition.

By sequenced addition we mean:

- according to a first embodiment, that the first adjuvant is added in one go, and that the second adjuvant is added in several times,

- according to a second embodiment, that the first adjuvant is added in several times, and that the second adjuvant is added in one go,

- according to a third embodiment, that the first adjuvant and the second adjuvant are added in several times.

According to the first embodiment, the first adjuvant is added in one portion, and the second adjuvant is added in 2 to 6 portions, preferably in 2 to 4 portions, preferably the first portion of the second adjuvant being added at the same time as the first adjuvant. Preferably, the time between two successive additions of the second adjuvant varies from 15 to 90 min, preferably from 15 min to 45 min.

According to the second embodiment, the second adjuvant is added in one portion, and the first adjuvant is added in 2 to 6 portions, preferably in 2 to 4 portions, preferably the first portion of the first adjuvant being added at the same time as the second adjuvant. Preferably, the time between two successive additions of the first adjuvant varies from 15 to 90 min, preferably from 15 min to 45 min.

According to the third embodiment, both the first adjuvant and the second adjuvant are added in 2 to 6 portions, preferably in 2 to 4 portions, together or separately. Preferably, the time between two successive additions of the first adjuvant and/or the second adjuvant varies from 15 to 90 min, preferably from 15 min to 45 min.

The sequenced addition of the first adjuvant and/or the second adjuvant advantageously makes it possible to maintain a reduced viscosity of the hydraulic composition in a more sustainable manner over time compared to the case where the first and second adjuvants are added together in one go. In particular, the management of the sequence of addition of the first and second adjuvants in the hydraulic composition in order to optimize the evolution of the properties of the hydraulic composition during its transport can be determined by the method described in application WO 2016/196599.

FIGURES

There is a graph representing the evolution of the viscosity of compositions E1* and E41 to E44 as a function of time (example 4).

The invention will appear more clearly on reading the description which follows, given solely as a non-limiting example.

In all examples, unless otherwise stated, the contents of first adjuvant(s), second adjuvant and any additional adjuvants are expressed by mass relative to the total dry mass of the non-adjuvanted hydraulic binder composition.

Note that in all examples, the hydraulic compositions evaluated have similar workability, which allows the viscosity of each composition to be correctly compared.

Example 1: Effect of the association between a first adjuvant and a second adjuvant on workability and v iscosity of a hydraulic composition mortar type

A mortar-type hydraulic composition with the following composition was used.

Composition of the mortar:

Mass (kg/m ³ ) % by mass relative to the total dry mass of the non-adjuvanted hydraulic binder composition CEM I 52.5 R cement Clinker 264.4 35.7% Calcium sulfate 13.7 Minor phases 13.1 Limestone filler 416.3 50.0% Calcined clay no. 1 118.9 14.3% Sand (0/4 mm) 1626.0 - Water 279.7
(ratio e/l = 0.336) -

Minor phases of CEM I 52.5 R cement:

Quicklime – CaO 0.3% Calcium dihydroxide - Ca(OH) ₂ 1.8% Calcium carbonate - CaCO ₃ 0.6% Periclase - MgO 0.6% Dolomite - CaMgCO ₃ 1.0%

DRX analysis of calcined clay no. 1:

Phase Formula %mass Quartz SiO ₂ 40.6 Calcite CaCO ₃ 0.8 Hematite Fe ₂ O ₃ 1.0 Rutile TiO ₂ 0.3 Amorphous phase 52.6 Illite (K,H ₃ O)(Al,Mg,Fe) ₂ (Si,Al) ₄ O ₁₀ [(OH) ₂ ,(H ₂ O)] 4.2 Kaolinite Al ₂ Si ₂ O ₅ (OH) ₄ 0.7

This mortar is adjuvanted with the following adjuvant(s):

- polymer A1:

- polymer A2 consisting of the following units:

with a = 82.3, b = 17.7 and z = 53.

- A3 polymer consisting of the following units:

with a = 55, b = 23.5, c = 21.5 and z = 17.

- A4 polymer consisting of the following units:

with a = 55, b = 23.5, c = 21.5 and z = 45 (IIb) or z = 17 (IIc).

- polymer B1 = MPEG-5000.

Other additional adjuvants such as sodium gluconate, sodium lignosulfonate, and/or a sugar (sucrose) have also been added to some compositions.

The polymers and any additional adjuvants are added to the mortar in the proportions of the following Table 4, corresponding to their proportion by mass relative to the total dry mass of the non-adjuvanted hydraulic binder composition described in Table 1 above.

The mortar is prepared using a 5L planetary mixer in accordance with EN 196-1 in a room maintained at T=20 ± 2°C and 65 ± 5% relative humidity. The volume of the batch is 1.5 L. The mixing protocol is as follows:

- Introduction of aggregates and mixing for 30 seconds at 62 rpm

- Add a third of the water for 30 seconds at 62 rpm

- Rest for 4 minutes (sand pre-moistening time)

- t ₀ : Introduction of the hydraulic binder composition and mixing at 62 rpm for 1 minute

- Introduction of the remaining two thirds and the adjuvants (in 15 seconds) for 1 minute at 62 rpm

- Stop mixing and scrape the sides of the mixer bowl for 30 seconds

- Mix the mixture at 125 rpm for 1 minute.

The workability of the adjuvanted hydraulic compositions (spreading) thus obtained was evaluated according to the following protocols:

- The first measurement is carried out at t ₀ +5min.

-The spreading cone with a volume of 700 ^cm3 (upper diameter = 50 ± 0.5 mm; lower diameter = 100 ± 0.5 mm; height = 150 ± 0.5 mm) is lightly moistened using a sponge and placed in the centre of a slightly moistened polypropylene spreading plate free of impurities.

- The cone is filled in one go with the mortar and the surface is leveled using a leveling rule.

- The cone is lifted perpendicular to the spreading plate without shocks or obstacles to the flow.

- The mortar adhering to the internal walls of the cone is scraped to maintain a constant volume of mortar.

- The spreading diameter retained is the average of 3 measurements of the diameters of the mortar cake equally distributed.

- Between each measurement, the mortar is kept in the mixer bowl covered with a suitable lid to prevent the water from evaporating.

The evolution of viscosity was determined according to the following protocol:

- The first measurement is carried out at t ₀ +5min

• Diamètre supérieur = 150 mm
• Ajutage inférieur = 17,2 mm
• Rayon = 25°
• Volume du tronc de cône évalué (entre les 2 repères fixes) = 545 cm³

- The viscosity of the mortar is evaluated through a flow measurement of a constant volume of mortar in an inverted cone whose dimensions are:

• Upper diameter = 150 mm
• Lower nozzle = 17.2 mm
• Radius = 25°
• Volume of the evaluated truncated cone (between the 2 fixed marks) = 545 ^cm3

- The cone is plugged and slightly moistened before filling. The cone is completely filled with mortar before starting the measurement.

- The cone is uncapped and the timer is started when the mortar reaches the first mark and stopped when the mortar reaches the second mark.

- The time taken for the mortar volume to pass through is measured using a stopwatch to the nearest tenth of a second.

The results obtained are also presented in the following Table 4:

E0* E1* E2 E3* E4 E5* E6 E7* E8 Hydraulic composition Polymer A1 - 0.570% 0.531% - - 0.332% 0.332% 0.347% 0.347% Polymer A2 - - - 0.182% 0.182% - - - - Polymer A3 - - - 0.121% 0.121% - - - - Polymer A4 - - - - - 0.016% 0.016% 0.023% 0.023% Polymer B1 0.080% - 0.020% - 0.080% - 0.080% - 0.080% Sodium gluconate - - - - - 0.030% 0.030% - - Sodium lignosulfonate - - - - - - - 0.002% 0.002% Sugar (Sucrose) - - - - - - - 0.013% 0.013% Workability (spread, in mm) 5 min 100 250 250 240 270 250 275 250 280 30 min - 250 260 230 310 230 270 250 280 60 min - 270 270 220 275 215 260 240 280 90 min - 280 280 - 260 210 255 245 280 120 min - 280 285 - 245 200 250 225 275 Viscosity (flow time, in s) 5 min Not measurable** 104.0 45.0 155.0 56.4 70.0 49.0 56.0 45.6 30 min - 96.0 47.0 - 44.8 95.0 61.0 78.0 50.0 60 min - 85.0 49.0 - 54.6 174.0 72.0 153.0 65.0 90 min - 84.0 48.0 - 62.0 200.0 82.0 175.0 68.0 120 min - 86.0 49.0 - 75.9 - 87.0 - 65.0

* : comparative

**: no flow

These results show that the combination of a first and a second adjuvant as defined according to the present invention advantageously makes it possible to reduce the viscosity of the hydraulic compositions while maintaining comparable workability. Indeed, the compositions E2, E4, E6 and E8 according to the invention have a workability similar to that of the comparative compositions E1*, E3*, E5* and E7*, but have a viscosity very significantly lower than E1*. A synergistic effect is therefore observed between the first and the second adjuvant.

The comparison between E1* and E2 also shows that the addition of a second adjuvant makes it possible to obtain hydraulic compositions with comparable workability, but a much lower viscosity, while reducing the total quantity of adjuvants. This therefore advantageously makes it possible to reduce costs, while having a gain in performance.

It should also be noted that this synergistic effect is independent of the way in which the second adjuvant is introduced (either upstream, by mixing them with the sand before preparing the mortar, or at the end, by adding them to the mortar).

E example 2 : V variation of the nature of the second adjuvant

The mortar and the methods for measuring workability and viscosity are the same as in Example 1, as is the nature of the polymer A1.

The second adjuvants used are as follows:

B1 = MPEG 5000

B2 = HPEG 2400

B3 = PEG 6000

B4 = PEG 20000

The hydraulic compositions tested as well as their workability and viscosity are listed in the following table 5:

E20* E21 E22 E23 E24 E25 Hydraulic composition Polymer A1 0.570% 0.570% 0.570% 0.570% 0.510% 0.510% B1 = MPEG 5000 - 0.080% - - - - B2 = HPEG 2400 - - 0.080% - - - B3 = PEG 6000 - - - 0.080% 0.080% - B4 = PEG 20000 - - - - - 0.080% Workability (spreadability, in mm) 5 min 270 290 260 310 255 300 30 min 260 280 255 310 240 300 60 min 250 290 260 310 245 300 90 min 250 290 260 320 250 310 120 min 260 290 260 315 250 310 Viscosity (flow time, in s) 5 min 83.0 36.0 58.0 26.4 45.6 26.3 30 min 77.0 35.0 62.0 25.9 51.7 25.7 60 min 76.0 37.0 55.0 24.2 50.6 23.4 90 min 67.0 29.0 53.0 22.7 45.2 25.1 120 min 60.0 34.0 52.0 22.0 49.7 23.8

* : comparative

These results demonstrate that all linear polyethers, and in particular all polyethylene glycols, substituted or not, make it possible to reduce viscosity without major impact on workability.

Example 3 : Effect of the association first/second adjuvant on the mechanical performance of admixed mortars

The mortar and the methods for measuring workability and viscosity are the same as in Example 1, as are the nature of the first and second admixtures.

The air content is determined from the theoretical density of the mortar according to the following protocol:

- At t ₀ +5min, fill a pot with known volume density (V=500 mL) with the mortar in one go.

- The mortar is leveled on the surface using a leveling rule

- The mass of the known volume of fresh mortar is given to the nearest tenth of a gram.

- The air content is determined by calculating the relative variation compared to the theoretical density of the mortar considered without air.

The compressive strength of 4x4x16cm ³ prismatic specimens is determined according to standard EN 196-1.

E30* E31 E32 E33 Hydraulic composition Polymer A1 0.392% 0.392% 0.392% 0.392% Polymer A4 0.016% 0.016% 0.016% 0.016% Polymer B1 - 0.020% 0.080% 0.320% Workability (spread, in mm) 5 min 225 255 270 305 30 min 215 260 270 310 60 min Not measurable 255 265 305 90 min Not measurable 240 255 300 120 min Not measurable 225 250 290 Viscosity (flow time, in s) 5 min Non-measurable (NM)** 78.0 50.0 35.0 30 min Not measurable** 79.0 55.0 35.7 60 min Not measurable** 86.0 58.0 39.3 90 min Not measurable** 102.0 66.0 43.1 120 min Not measurable** 79.0 48.3 Air content (% by volume) 5 min 2.1% 2.7% 2.3% 2.7% Compressive mechanical strength (MPa) 8 p.m. 7.5 6.9 7.1 6.4 28 days 51.0 50.0 48.9 51.9 20 hour gap 0.5 0.1 0.1 0.0 gap 28 days 0.1 1.6 1.0 0.2

* : comparative

**: no flow

These results demonstrate that:

1) The introduction of the second adjuvant does not involve an increase in the air content in the adjuvanted mortar, therefore does not lead to additional air entrainment,

2) The introduction of the second adjuvant does not significantly impact the mechanical resistances at 20 hours and 28 days.

Example 4: Effect of the second addition sequence adjuvant in the mortar

According to a first protocol (examples E1*, E41 and E42), the second adjuvant (MPEG 5000) is added in one go, at the same time as the addition of the first adjuvant(s). This corresponds to the protocol for preparing the adjuvanted hydraulic compositions of the previous examples.

According to a second protocol (examples E43 and E44), the addition of the second adjuvant is sequenced, that is to say that a first part is added at the same time as the first adjuvants, and a second part is added after 30 minutes, and possibly a third part is added after one hour after the addition of the first part.

The workability and viscosity of the hydraulic compositions obtained were determined according to the methods described in Example 1.

E1* E41 E42 E43 E44 Hydraulic composition Polymer A1 0.570% 0.343% 0.343% 0.343% 0.343% Polymer A4 - 0.021% 0.021% 0.021% 0.021% Polymer B1 - 0.160% 0.080% 0.080%
+
0.080% (after 30 min) 0.080%
+
0.080% (after 30 min)
+
0.020% (after 1h) Workability (spreadability, in mm) 5 min 250 265 245 - - 30 min 250 260 250 250 - 60 min 270 255 - 250 245 90 min 280 245 - - 260 120 min 280 240 - - 240 Viscosity (flow time, in s) 5 min 104.0 55.0 85.0 - - 30 min 96.0 59.0 76.0 50.9 - 60 min 85.0 69.0 - 60.5 49.9 90 min 84.0 82.0 - - 46.5 120 min 86.0 96.0 - - 56.7

These results demonstrate that the sequenced addition of the second adjuvant in the hydraulic composition adjuvanted with the first adjuvants makes it possible to further reduce the viscosity compared to a single addition (compare in particular the viscosity at 30 minutes and 60 minutes of compositions E41 and E43, comprising the same quantities of first and second adjuvants).

This is also visible on the , representing the evolution of the viscosity of compositions E1* and E41 to E44 as a function of time.

Example 5: Effect of e the presence of the second adjuvant on the water demand of mortar

The following hydraulic binder composition is prepared:

Clinker: 158.8 g + Calcium sulfate: 8.2 g + minor phases: 7.8 g (see Table 2 of example 1)

Limestone filler: 250.0 g

Calcined clay no. 1: 71.4 g

The water demand of this hydraulic binder composition, in the presence or absence of MPEG 5000, is determined according to the standard consistency determination method described in EN 196-3:2016. The results are given in the following Table 8:

Mass of hydraulic binder (g) Addition water (g) Water demand (%) Without MPEG 500 124.2 24.8% In the presence of MPEG 5000 (0.4%) 500 124.4 24.9%

No effect of MPEG 5000 is observed on the water demand of the hydraulic binder composition. This demonstrates that MPEG 5000 does not influence the viscosity of the hydraulic binder paste by modifying its water demand, and that it is only through its association with a first admixture that the effects on viscosity can be obtained. The second admixture therefore boosts the effect of the first admixture, which is totally surprising given that it has no influence on the water demand and therefore on the viscosity if used alone.

Example 6 : Effect of the association between a first adjuvant and a second adjuvant on the workability and the v iscosity of a hydraulic composition kind concrete

A concrete-type hydraulic composition with the following composition is used.

Concrete composition:

Mass (kg/m ³ ) % by mass relative to the total dry mass of the non-adjuvanted hydraulic binder composition CEM I 52.5 R cement Clinker 133.3 35.7% Calcium sulfate 6.9 Minor phases (see Table 2) 6.6 Addition Limestone filler 210 50.0% Calcined clay Calcined clay no. 1 60 14.3% Sand (0/4 mm) 721 - Aggregates (10/20 mm) 1002 - Water efficient 141
(ratio e/l = 0.336) -

The first and/or second adjuvants are added to the concrete in the proportions of the following table 8, corresponding to the proportion by mass relative to the total dry mass of the non-adjuvanted hydraulic binder composition described in table 6 above.

Polymer A5 consists of the following units:

with a = 65, b = 35 and z = 53.

Other polymers are as defined in Example 1.

The concrete is prepared using a 30L capacity ZZ 30 HE Zyklos synchronous mixer in a room maintained at T=20 ± 2°C and 65 ± 5% relative humidity. The volume of the batch is 15L. The mixing protocol is as follows:

- Introduction of aggregates and mixing for 30 seconds at 45 rpm

- Add a third of the water for 30 seconds at 45 rpm

-Rest for 4 minutes (pre-moistening time of the sand)

- t ₀ : Introduction of the hydraulic binder composition and mixing at 45 rpm for 1 minute

- Introduction of the remaining two thirds and the adjuvants (in 15 seconds) for 1 minute at 45 rpm

- Stop mixing and scrape the sides of the mixer bowl for 30 seconds

- Mix the whole mixture at 45 rpm for 2 minutes

The workability of the adjuvanted hydraulic compositions (slump) thus obtained was evaluated according to the following protocols:

The initial workability by measurement of the initial subsidence at the Abrams cone was determined according to EN 12350-2.

The initial viscosity by measurement of the flow time at the inverted Abrams cone was determined according to standard NF P18-469.

The results obtained are also presented in the following Table 10:

E61* E62 E63 E64 Hydraulic composition Polymer A1 0.347% 0.347% 0.336% 0.150% Polymer A4 0.016% 0.016% 0.011% - Polymer A5 - - - 0.076% Polymer B1 - 0.080% 0.080% 0.040% Sodium gluconate - - 0.044% 0.059% Workability (sag, in mm) 5 min 215 215 230 220 Viscosity (flow time, in s) 5 min 15.3 8.0 4.3 4.5

* : comparative

These results show that the combination of a first and a second adjuvant as defined according to the present invention advantageously makes it possible to reduce the viscosity of the hydraulic concrete compositions while maintaining a comparable and high workability. These results are similar to those obtained on the mortars in the previous examples.

Example 7 : Effect of e the presence of the second adjuvant added to the grinding of a calcined clay

Calcined clay No. 2 was ground in a 5 kg capacity ball mill (800 to 900 rpm mill). The dosage of second additive (polymer B1) relative to the mass of calcined clay is 0.02% by weight. The grinding time is controlled to ensure reaching a D50 (particle size for which 50% of the sample volume has a smaller or larger particle size) of 19 µm.

A hydraulic mortar type composition with the following composition was used. The methods for measuring workability and viscosity are the same as in Example 1, as are the nature of the first and second admixtures.

DRX analysis of calcined clay no. 2:

Phase Formula %mass Quartz SiO ₂ 39.9 Calcite CaCO ₃ 0.2 Hematite Fe ₂ O ₃ 0.2 Rutile TiO ₂ 1.0 Amorphous phase 31.0 Illite (K,H ₃ O)(Al,Mg,Fe) ₂ (Si,Al) ₄ O ₁₀ [(OH) ₂ ,(H ₂ O)] 5.3 Kaolinite Al ₂ Si ₂ O ₅ (OH) ₄ 7.7

Without polymer B1 With polymer B1 Particle size distribution D10 (µm) 2.0 2.1 D50 (µm) 19.2 19.1 D90 (µm) 90.0 85.8

Composition of the mortar:

Mass (kg/m ³ ) % by mass relative to the dry mass of the non-adjuvanted hydraulic binder composition CEM I 52.5 R cement Clinker 264.4 35.7% Calcium sulfate 13.7 Minor phases (see Table 2) 13.1 Limestone filler 416.3 50.0% Calcined clay n°2 118.9 14.3% Sand (0/4 mm) 1626.0 Water 279.7
(ratio e/l = 0.336)

The polymers and any additional adjuvants are added to the mortar in the proportions of the following Table 14, corresponding to their proportion by mass relative to the total dry mass of the unadjuvanted hydraulic binder composition described in Table 13 above. Polymer B1 was added to the calcined clay at the time of its grinding, while polymer A1 was added to the mortar.

The results obtained are also presented in the following table:

E71* E72 Hydraulic composition Polymer A1 0.57% 0.57% Polymer B1 0.02%** Workability (spreadability, in mm) 5 min 300 335 30 min 350 360 60 min 350 370 90 min 360 380 120 min 360 380 Viscosity (flow time, in s) 5 min 58.1 41.2 30 min 44.6 34.2 60 min 41.1 30.6 90 min 39.0 31.1 120 min 38.2 27.8

* : comparative

** added upstream to the grinding of activated clay

These results are similar to those obtained on the mortars in the previous examples. These results show that it is possible to add the second adjuvant as soon as the calcined clay is ground.

Claims (17)

Composition of adjuvanted hydraulic binder comprising:
- a hydraulic binder composition comprising, relative to the dry mass of the hydraulic binder composition:
- from 30% to 95% by mass of clinker, and
- from 5% to 70% by mass of activated clay,
- from 0% to 60% by mass of calcium carbonate or magnesium carbonate or a mixture of calcium carbonate and magnesium carbonate, preferably limestone, and
- from 0% to 10% by mass of calcium sulfate;
- a first reducing or high water reducing adjuvant chosen from polyalkoxylated polycarboxylate polymers and polyalkoxylated phosphonate polymers, and any of their mixtures, and
- a second adjuvant chosen from the polymers of the following formula (B):

in which
“X” represents N or O,
“R” is selected from H, a C1-C10 alkyl group, a cyclohexyl group, an alkylaryl group and an unsaturated group,
“R'” is selected from OH, a C1-C10 alkyl group, a cyclohexyl group, an alkylaryl group, NH ₂ , COOH, a C1-C6 ester and an ammonium group,
“Alk” represents a C2-C6 alkylene group, linear or branched, and
“n” is an integer ranging from 2 to 10000, preferably 6 to 250. An admixed hydraulic binder composition according to claim 1, wherein the polyalkoxylated polycarboxylate polymers comprise units of the following formulas (I) and (II):


in which:
- “R2” and “R3” independently represent hydrogen or methyl,
- “M” independently represents H ⁺ or a cation of valence v chosen from an alkali metal ion, an alkaline-earth metal ion, a bi- or trivalent metal ion, an ammonium ion or an organic ammonium group,
- when “M” represents H, “v” represents 1, and when “M” represents a cation, “v” is the valence of the cation M,
- “R7” and “R8” independently represent hydrogen, methyl or a group of formula –COO(M) _{1/ v} with M and v as defined above,
- “m” represents 0, 1 or 2,
- “p” represents 0 or 1,
- “X” is Y or N, and
- “R1” represents a C1-C20 alkyl group, a cycloalkyl group, an alkylaryl group, or -[O-Alkyl] _z -OR6, wherein the “Alkyl” of each O-Alkyl unit of the group –[O-Alkyl] _z - independently represents a linear or branched alkylene comprising from 2 to 4 carbon atoms, and “R6” represents H, a C1-C20 alkyl group, a cyclohexyl group or an alkylaryl group, and “z” is an integer ranging from 2 to 250,
- “a” is a number ranging from 0.05 to 0.95, “a” being the mole fraction of units of formula (I) in the polymer, and
- “b” is a number ranging from 0.05 to 0.95, “b” being the mole fraction of units of formula (II) in the polymer. An admixed hydraulic binder composition according to claim 2, wherein in formulae (I) and (II) polycarboxylate polyalkoxylated polymers,
- “R2” represents H,
- “R3” independently represents hydrogen or methyl,
- “M” is sodium or calcium
- “a” is a number ranging from 0.20 to 0.90, preferably “a” is a number ranging from 0.40 to 0.85,
- “R7” represents H,
- “R8” independently represents hydrogen or methyl,
- X = O,
- R1 = -[O-Alkyl] _z -O-R6, with preferably:
- “Alkyl” represents -CH ₂ -CH ₂ -, -CH ₂ -CH ₂ -CH ₂ -, -CH ₂ -CH _{2 -CH 2 -CH 2} -, -CH ₂ -CHMe-, -CHMe-CH ₂ -, and/or
- at least 80% of the “Alkyl” of the group –[O-Alkyl] _z - represent -CH ₂ -CH ₂ -, or even all the “Alkyl” of the group –[O-Alkyl] _z - represent -CH ₂ -CH ₂ -, and/or
- “z” represents an integer ranging from 5 to 200, in particular from 10 to 100, preferably from 25 to 75, and/or
- “R6” represents H or Me,
- either p = 0 and m = 1 or 2, preferably 1, or p = 1 and m = 0, and
- “b” is a number ranging from 0.10 to 0.80, preferably “b” is a number ranging from 0.15 to 0.60. An admixed hydraulic binder composition according to any preceding claim, in which the polyalkoxylated phosphonate polymers are of the following formula (III):

in which
“R5” is a hydrogen atom or a monovalent hydrocarbon group having from 1 to 18 carbon atoms and optionally one or more heteroatoms;
the “Ri” are similar or different to each other and represent an alkylene such as ethylene, propylene, butylene, amylene, octylene or cyclohexene, or an arylene such as styrene or methylstyrene, the “Ri” optionally containing one or more heteroatoms;
“Q” is a hydrocarbon group having from 2 to 18 carbon atoms and optionally one or more heteroatoms;
“A” is an alkylene group having 1 to 5 carbon atoms;
the “Rj” are similar or different from each other and can be chosen from:
- the group A-PO ₃ H ₂ , A having the aforementioned meaning,
- an alkyl group comprising from 1 to 18 carbon atoms and which may carry [R5-O(Ri-O) _m ] groups, R5 and Ri having the aforementioned meanings,
"m" is a number greater than or equal to 0,
"r" is the number of groups [R5-O(Ri-O) _m ] carried by the set of Rj,
"q" is the number of groups [R5-O(Ri-O) _m ] carried by Q, the sum "r+q" is between 1 and 10,
"y" is an integer between 1 and 3,
“Q”, “N” and “Rj” may together form one or more cycles, this or these cycles may further contain one or more other heteroatoms. An admixed hydraulic binder composition according to any preceding claim, wherein the first admixture comprises a mixture of at least two polymers selected from polyalkoxylated polycarboxylate polymers and polyalkoxylated phosphonate polymers. Adjuvanted hydraulic binder composition according to any one of claims 2 to 4, in which the first adjuvant is chosen from:
- a polyalkoxylated polycarboxylate polymer, in which p = 0 and m = 1 or 2, preferably 1,
- a polyalkoxylated polycarboxylate polymer in which p = 1 and m = 0,
- a polyalkoxylated phosphonate polymer,
- and any mixture thereof,
preferably the first adjuvant comprises a mixture of at least two polymers chosen from:
- a polyalkoxylated polycarboxylate polymer, in which p = 0 and m = 1 or 2, preferably 1,
- a polyalkoxylated polycarboxylate polymer in which p = 1 and m = 0, and
- a polyalkoxylated phosphonate polymer. An admixed hydraulic binder composition according to any preceding claim, wherein in formula (B) of the second admixture, “Alk” is –CH ₂ -CH ₂ –. An admixed hydraulic binder composition according to any preceding claim, wherein the total content of first admixture is from 0.05% to 1.00% by mass, preferably from 0.10% to 0.80% by mass, preferably from 0.20% to 0.60% by mass, preferably from 0.25% to 0.50% by mass, preferably from 0.30% to 0.45% by mass, of the dry mass of the hydraulic binder composition. An admixed hydraulic binder composition according to any preceding claim, wherein the second admixture content is from 0.01% to 1.00% by mass, preferably from 0.02% to 0.80% by mass, preferably from 0.05% to 0.50% by mass, preferably from 0.06% to 0.30% by mass, preferably from 0.07% to 0.20% by mass, of the dry mass of the hydraulic binder composition. Adjuvanted hydraulic binder composition according to any one of the preceding claims, further comprising a setting retarder, preferably chosen from:
- a carboxylic or hydroxycarboxylic acid in neutral form or a salt thereof,
- a phosphonic acid in neutral form or a salt thereof,
- a sugar,
- a phosphate, and
- any of their mixtures. Adjuvanted hydraulic binder composition according to any one of the preceding claims, further comprising a third adjuvant chosen from water reducers or high water reducers and different from the first adjuvant, preferentially chosen from lignin derivatives such as lignosulfonate salts, sodium gluconate and sodium glucoheptonate. An admixed hydraulic binder composition according to any preceding claim, further comprising an alkoxylated glycol alkyl ether adduct of formula (C) R''O(AO) _x H, in which:
- “R''” represents H or an alkyl group, linear or branched, comprising from 1 to 22 carbon atoms, or a cycloalkyl comprising from 5 to 7 carbon atoms,
- “A” represents an alkylene, linear or branched, comprising from 1 to 4 carbon atoms, and
- “x” is an integer from 1 to 70. An admixed hydraulic binder composition according to any preceding claim, wherein the hydraulic binder composition comprises from 10% to 60% by mass, preferably from 30% to 60% by mass, preferably from 35% to 55% by mass, preferably from 40% to 50% by mass, of calcium carbonate or magnesium carbonate or a mixture of calcium carbonate and magnesium carbonate, preferably limestone, relative to the dry mass of the hydraulic binder composition. An admixed hydraulic binder composition according to any preceding claim, wherein the hydraulic binder composition comprises from 0% to 5% by mass, preferably from 1% to 5% by mass, of calcium sulfate, relative to the dry mass of the hydraulic binder composition. Hydraulic composition comprising the adjuvanted hydraulic binder composition according to any one of claims 1 to 14, water, optionally an aggregate and optionally a mineral addition. Use of the combination of a first adjuvant and a second adjuvant as defined according to any one of claims 1 to 9, as a fluidifier for a hydraulic composition comprising:
- a hydraulic binder composition comprising, relative to the dry mass of the hydraulic binder composition:
- from 30% to 95% by mass of clinker,
- from 5% to 70% by mass of activated clay,
- from 0% to 60% by mass of calcium carbonate or magnesium carbonate or a mixture of calcium carbonate and magnesium carbonate, preferably limestone, and
- from 0% to 10% by mass of calcium sulfate;
- water,
- possibly an aggregate, and
- possibly a mineral addition. Process for preparing a hydraulic composition according to claim 15, comprising a step of adding, simultaneously or sequentially, a first adjuvant and a second adjuvant as defined according to any one of claims 1 to 9, in a hydraulic composition comprising:
- a hydraulic binder composition comprising, relative to the dry mass of the hydraulic binder composition:
- from 30% to 95% by mass of clinker,
- from 5% to 70% by mass of activated clay,
- from 0% to 60% by mass of calcium carbonate or magnesium carbonate or a mixture of calcium carbonate and magnesium carbonate, preferably limestone, and
- from 0% to 10% by mass of calcium sulfate; and
- water,
preferably the first adjuvant is added in one portion, and the second adjuvant is added in 2 to 6 portions, preferably in 2 to 4 portions, preferably the first portion is added at the same time as the first adjuvant.