Treatment for deactivating clay in hydraulic compositions used in the construction industry

Abstract

The present invention relates to a process for deactivating clay in hydraulic compositions intended for construction, comprising the step of adding to the hydraulic composition or one of its components a clay deactivator which is a water-soluble polymer consisting of at least one acrylamide and / or vinylamine and / or vinylformamide monomer unit and optionally monomer units of chemical nature different from those of the clay deactivator, characterized in that its weight average molecular weight is between Mw L and Mw H.

Description

[Technical Field]

[0001] The present invention relates to a treatment for deactivating clay in aqueous construction compositions. [Background technology]

[0002] Cementitious aqueous compositions used on construction sites contain fine aggregates of varying qualities, particularly sand. This dilution sometimes necessitates rock crushing. Generally, fine aggregates contain significant amounts of clay. Some of them are swelling, and when they spread during sliding, their outer and inner surfaces can absorb so much water that they hydrate, leading to a deterioration in aggregate quality and a significant change in the properties of the hydraulic composition. In the wet state, this can cause rheological problems, while in the hardened state, it can lead to safety issues, such as embrittlement of the structure.

[0003] Aqueous compositions are characterized by the water / aqueous binder ratio. This ratio determines the strength and durability of the finished cement. The lower the water / aqueous binder ratio, the greater the strength and durability. Therefore, superplasticizers are used to lower this ratio. However, the clay in the fine aggregate traps water and superplasticizer, resulting in poor performance during installation and excessive admixture consumption. The variability caused by the clay in the fine aggregate makes it difficult to control the dosage of superplasticizer.

[0004] To circumvent these problems, synthetic polymers have been developed to deactivate clay. WO 98 / 58887 proposes the use of agents that modify the activity of clay to prevent the clay from absorbing EO / PO-type superplasticizers and thereby improve the performance of cement and concrete. In particular, the use of inorganic or organic cation containing cationic polymers, such as alkoxylated quaternary polyamines, is proposed.

[0005] WO 2006 / 032785 proposes the use of cationic polymers with a charge density of more than 0.5 meq / g, in particular cationic polymers obtained by condensation of epichlorohydrin with dialkylamines.

[0006] WO 2013 / 124003 proposes the use of other cationic polymers such as polyamines functionalized with cationic groups.

[0007] The inert clay polymers described in the prior art are cationic, and research has focused on polymers with high cationic properties to optimize performance, but these cationic polymers have many problems due to their quaternary ammonium functionality and high chloride content.

[0008] Chlorides damage cementitious matrices and affect their mechanical strength. In addition to the physical and chemical damage to these matrices, the risk of damage to engineered structures is increased by corrosion damage to metal reinforcement.

[0009] Demineralization of rebar begins when chloride ions penetrate the upper concrete and reach a critical concentration in the first layer of rebar. Currently, the critical concentration for concrete mixes around the world is standardized, based on scientific knowledge, observation, and experience, and is sometimes set at 0.2% chloride by mass of cement or less.

[0010] The phenomenon is highly complex and poses serious problems for the durability and safety of construction. For this reason, the industry has introduced standards such as NF EN 14629 for measuring the chloride content of hardened concrete. This standard is primarily intended to estimate the risk of chloride corrosion of reinforcing steel.

[0011] For this reason, the construction industry is looking for solutions to reduce the chloride concentration in hydraulic compositions as much as possible.

[0012] WO 2018 / 054991 relates to a process for obtaining cationic high-density polymers with reduced chloride content. The cationic polymers can be used in mineral binder-based compositions to inhibit clay. However, even after this process, the chloride content remains high and does not meet the standard requirements. This leaves existing solutions insufficient. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] International Publication No. 98 / 58887 [Patent Document 2] International Publication No. 2006 / 032785 [Patent Document 3] International Publication No. 2013 / 124003 [Patent Document 4] International Publication No. 2018 / 054991 Summary of the Invention [Problem to be solved by the invention]

[0014] The present invention provides a clay deactivator that improves the performance of hydraulic compositions intended for construction applications and that is chloride-free. [Means for solving the problem]

[0015] The present invention is based on the observation that water-soluble polymers of specific chemical properties and molecular weights provide improved passivation performance for clay in aqueous construction compositions and are chloride-free, thereby meeting specification requirements.

[0016] This is also based on the observation that the clay deactivation properties are further improved when these water-soluble polymers contain a specific amount of hydrophobic monomer units.

[0017] The present invention makes it possible to achieve the environmental objectives inherent in new technological innovations, where improved polymer performance is expected to reduce polymer consumption.

[0018] Furthermore, as indicated above, the polymers of the present invention are chloride-free, which not only results in stronger construction materials, but also allows for a significant reduction in the water consumption and pollution typically associated with washing sand and fine aggregates on filter belts, thereby saving this resource for more efficient use and avoiding the pollution of the environment with contaminated water.

[0019] Also, because it does not contain chlorides, it can prevent salt damage from water, which can sometimes lead to desertification.

[0020] Finally, the monomer used in the polymer has a smaller carbon footprint than monomers used in prior art polymers: it consists of just three carbons, the minimum for any functional polymer (except polyethylene), and can be produced in a short time compared to petroleum.

[0021] This makes the polymer more environmentally friendly and its users more amenable, both in terms of its composition and its application benefits.

[0022] The present invention relates to a process for deactivating clay in hydraulic compositions intended for construction. The process comprises the step of adding to the hydraulic composition or one of its components a clay deactivator which is a water-soluble polymer ( ) consisting of at least one acrylamide and / or vinylamine and / or vinylformamide monomer unit, optionally with monomer units of a chemical nature different from that of the clay deactivator, characterized in that its weight-average molecular weight is between Mw L and Mw H, and whose chemical nature is as follows: - Mw L=[AM] * 30+[VA] * 10+[VF] * 10+ [MO] * 20, also - Mw H=[AM]* 500+[VA] * 3000+[VF] * 3000+[MO] * 2000, where [AM], [VA], [VF], and [MO] are the proportions (mol%) of monomers relative to the total number of monomer units in the polymer, and the monomer units are acrylamide, vinylamine, vinylformamide, and units of chemical properties different from those listed above. The sum of [AM], [VA], [VF], and [MO] is equal to 100 mol%.

[0023] In a preferred embodiment, the polymer of the present invention is selected from: homopolymer of acrylamide, -Homopolyvinylamine -Homopolyvinylformamide - a copolymer consisting of two monomer units selected from acrylamide, vinylformamide, and vinylamine; - a terpolymer consisting of acrylamide, vinylformamide and vinylamine monomer units, - A terpolymer comprising at least two monomer units selected from acrylamide, vinylformamide, and vinylamine, and at least one monomer unit having hydrophobic properties.

[0024] In accordance with the present invention, the clay deactivator is a composition comprising at least two water-soluble polymers.

[0025] Water-soluble polymers according to the present invention are desirably non-ionic, that is, do not contain anionic or cationic charges.

[0026] In particular, it is essential that the water-soluble polymer according to the present invention does not contain chloride ions.

[0027] The present invention also relates to a hydraulic composition intended for construction purposes, which comprises a fine aggregate according to the invention, at least one superplasticizer and at least one clay deactivator.

[0028] In the present invention, the term "water-soluble polymer" means a polymer that forms an aqueous solution when dissolved in water at 25°C at a concentration of 20 g / L with stirring.

[0029] The term "polyacrylamide" refers to a polymer composed of acrylamide monomer units, "polyvinylamine" refers to a polymer composed of vinylamine monomer units, and "polyvinylformamide" refers to a polymer composed of vinylformamide monomer units.

[0030] "Superplasticizer" refers to a polymer that reduces water content, e.g., maintains high fluidity for extended periods and maintains high slump in hydraulic compositions. Chemically, these superplasticizers are carbon chain polymers, such as polycarboxylates, with oxyalkylated side chains, such as ethoxy or propoxy.

[0031] "Nonionic polymer" refers to a polymer that does not have any cationic or anionic charges on the polymer chain.

[0032] "Hydraulic composition" defines a hydraulically setting composition, in particular mortar, concrete and cementitious compositions for the construction industry.

[0033] By "one of its components", when this expression refers to a hydraulic composition, it is meant the conventional components of hydraulic compositions known to those skilled in the art, such as fine aggregates (sand, limestone, etc.), superplasticizers, and cementitious binders, e.g., hydraulic binders such as mortar or concrete, and also includes superplasticizers and hydraulic binders, such as cementitious binders, e.g., mortar or concrete.

[0034] "Fine aggregate" refers to fine aggregates of different particle sizes, such as sand and gravel. The fine aggregates may be of any mineral nature, such as calcareous, siliceous, or siliceous. In particular, fine aggregates such as sand, as described in the context of the present invention, include clays.

[0035] "Clay" refers to aluminum and / or magnesium silicates, especially phyllosilicates, which have a layered structure typically spaced about 7 to about 14 angstroms apart. However, the term also includes other types of clays, especially amorphous clays. Clays commonly found in aggregates include montmorillonite, illite, kaolinite, and muscovite.

[0036] The proportion of acrylamide and / or vinylamine and / or vinylformamide monomer units in the water-soluble polymer of the present invention is at least 70 mol % relative to the total monomer units of the polymer. Preferably, it is at least 80 mol %, and even more preferably 90 mol %, and even more preferably 95 mol %. In addition to acrylamide, vinylformamide, and vinylamine monomer units, the polymer of the present invention may contain monomer units of a different chemical nature than those mentioned above. The aforementioned "chemical nature" refers to acrylamide, vinylformamide, and vinylamine. These monomer units of a different chemical nature may be hydrophobic, cationic, anionic, or zwitterionic monomer units, with hydrophobic monomer units being preferred.

[0037] The polymer according to the present invention preferably consists exclusively of acrylamide and / or vinylamine and / or vinylformamide monomer units, and optionally contains hydrophobic monomer units.

[0038] The water-soluble polymer is preferably selected from acrylamide homopolymer, homopolyvinylamine and homopolyvinylformamide, with homopolyvinylamine and homopolyvinylformamide being preferred.

[0039] Acrylamide / vinylamine copolymers preferably contain only acrylamide and vinylamine monomer units. Acrylamide / vinylformamide copolymers preferably contain only acrylamide and vinylformamide monomer units. Vinylamine / vinylformamide copolymers preferably contain only vinylamine / vinylformamide monomer units. Acrylamide / vinylamine / vinylformamide terpolymers preferably contain only acrylamide, vinylamine, and vinylformamide monomer units. Polymers according to the present invention also preferably contain hydrophobic monomer units.

[0040] The proportion of acrylamide, vinylamine and / or vinylamide monomer units can be adjusted.

[0041] The polymers of the present invention preferably contain 0.001 to 20 mol % of hydrophobic monomer units, preferably 0.1 to 15 mol %, and more preferably 0.1 to 10 mol %. The monomers with hydrophobic properties are selected from the group consisting of esters of (meth)acrylic acid with alkyl, hydroxyalkyl, and arylalkyl groups, preferably propoxylated, ethoxylated, ethoxylated, or ethoxylated and propoxylated; (meth)acrylamide derivatives with alkyl, hydroxyalkyl, arylalkyl, propoxylated, ethoxylated, ethoxylated and propoxylated, or dialkyl chains; and alkylaryl sulfonates. Preferably, the monomers are selected from hydroxyethyl acrylate, ethylhexyl acrylate, hydroxypropyl acrylate, butyl acrylate, propyl acrylate, dimethylacrylamide, butylacrylamide, and tert-butylacrylamide.

[0042] The presence of hydrophobic monomers in the polymers of the present invention allows for a wider range of dosages to improve performance, making the clay deactivator more flexible for use in the field, whether at the fine aggregate quarry or in the production of hydraulic compositions, allowing the professional to adjust the dosage to obtain optimum performance.

[0043] Mannich products obtained by reacting a polymer of acrylamide monomer units with formaldehyde and dimethylamine are also polymers of the present invention. These polymers typically do not contain chloride ions. These products can be protonated by adding a non-chlorine alkylating agent, preferably diethyl sulfate. The molecular weight of the Mannich products of the present invention is between Mw L and Mw H.

[0044] Throughout this invention, it is understood that mole % of polymer monomers equals 100%.

[0045] As already mentioned, the polymers according to the invention should contain no cationic or anionic charges at the use pH of the product, which is as far as possible generally between 10 and 13, and preferably no cationic, anionic or zwitterionic monomer units.

[0046] The weight average molecular weight of the polymers according to the invention, expressed in Daltons, is between Mw L and Mw H, and is as follows: - Mw L=[AM] * 30+[VA] * 10+[VF] * 10+ [MO] * 20, also - Mw H=[AM] * 500+[VA] * 3000+[VF] * 3000+[MO] * 2000, Here, [AM], [VA], [VF] and [MO] respectively represent the proportions of acrylamide, vinylamine and vinylformamide monomer units with different chemical properties to the total number of monomer units in the polymer, expressed in mol%.

[0047] The weight average molecular weight of the polymer according to the invention lies in the range [Mw L - Mw H], Mw L consisting of the lower value of the range and Mw H consisting of the upper value of the range.

[0048] When a polymer is composed of multiple types of acrylamide, vinylamine, or vinylformamide monomer units with different chemical properties, the monomer ratio [MO] is equal to the sum of the ratios of these monomer units with different chemical properties.

[0049] When a polymer is composed of, for example, 90 mol % acrylamide monomer units, 5 mol % butyl acrylate monomer units, and 5 mol % dimethylacrylamide monomer units, then [MO] is equal to 10 mol %, Mw L is equal to 2900 daltons, and Mw H is equal to 65000 daltons.

[0050] When the water-soluble polymer according to the present invention is composed of at least 80 mol % acrylamide monomer units, its weight average molecular weight is preferably 2.5 * Mw L and 0.8 * Mw H, plus 3.3 * Mw L and 0.6 * These preferred ranges therefore constitute a more restricted range of weight average molecular weight than the aforementioned [Mw L - Mw H] range. When the polymer according to the invention is an acrylamide homopolymer, its weight average molecular weight is preferably 7,500 to 40,000 daltons, and even 10,000 to 30,000 daltons.

[0051] When the water-soluble polymer according to the invention is composed of at least 80 mol % vinyl foam and / or vinyl foam amide monomer units, its weight average molecular weight is preferably 2 * Mw L and 5 / 6 * Mw H, plus 5 * Mw L and 2 / 3 * These preferred ranges therefore constitute a more restricted range of weight average molecular weight than the aforementioned [Mw L - Mw H] range. When the polymer according to the present invention is a homopolyvinylamide or homopolyvinylformamide, its preferred weight average molecular weight is preferably 7,500 to 40,000 daltons, and even more preferably 10,000 to 30,000 daltons.

[0052] According to the invention, the polymers may have a linear, branched, star-shaped, comb-shaped, dendritic or block structure. The polymers may be linear or structured, preferably linear. Structured polymers are non-linear polymers with side chains.

[0053] In general, the polymers do not require the development of a specific polymerization process and can be obtained using any polymerization technique well known to those skilled in the art, such as solution polymerization, gel polymerization, precipitation polymerization, emulsion polymerization (aqueous or inverse), suspension polymerization, reactive extrusion polymerization, underwater polymerization, micellar polymerization, etc.

[0054] Polymerization is generally free radical, preferably solution, and can include free radical polymerization using UV, azo, redox, or thermal initiators, as well as controlled radical polymerization (CRP) or matrix polymerization techniques.

[0055] A particularly advantageous technique for preparing the polymers of the present invention is RAFT (Reversible Addition-Fragmentation Chain Transfer) polymerization, which allows the synthesis of low-dispersity, highly functional polymers with controlled architectures (block, star, comb, etc.).

[0056] Polyvinylamine can be obtained as follows: - Hoffmann degradation of (co)polymers containing at least one nonionic monomer selected from the group consisting of, but not limited to, acrylamide, methacrylamide, N,N-dimethylacrylamide, t-butylacrylamide, octylacrylamide, and / or - (co)polymerization reaction of at least one monomer of formula (I): [ka] wherein R1 and R2 are each independently a hydrogen atom or an alkyl chain having 1 to 6 carbon atoms; Some or all of the -CO-R1 groups are then removed, for example by hydrolysis, to form amine functions.

[0057] Examples of monomers of formula (I) include N-vinylformamide, N-vinyl-N-methylformamide, N-vinylacetamide, N-vinyl-N-methylacetamide, N-vinyl-N-ethylacetamide, N-vinylpropianamide, N-vinyl-N-methylpropianamide, N-vinylbutyramide, etc. Preferably, the monomer is N-vinylformamide.

[0058] These monomers of formula (I) can be used alone or copolymerized with other monomers in the broad sense, such as acrylamide or hydrophobic monomers, provided that the latter are not sensitive to hydrolysis.

[0059] Polyvinylamine is preferably obtained by hydrolysis (preferably basic) of polyvinylformamide, which is obtained by methods known to those skilled in the art.

[0060] Gel permeation chromatography (GPC) is used to measure the weight-average molecular weight. The weight-average molecular weight is measured using an Agilent 1260 Infinity system equipped with a Dawn HELOS, OPtilab T-Rex multi-angle light scattering detector, and two columns in series: Shodex SB 807-HQ and Shodex 805-HQ. The sample is diluted to 1000 ppm with saline and filtered through a 1.2 μm filter. Direct measurement of polyvinylamine is complex, and its molecular weight is measured using the same instrument system for the desired polyacrylamide or poly(N-vinylformamide) precursor, assuming quantitative conversion to polyvinylamine, i.e., complete reaction.

[0061] The polymeric clay deactivator can be used in different forms, preferably in the form of an aqueous solution containing 1 to 50% by weight of the deactivator, which is added by pouring or spraying into the hydraulic composition or one of its components.

[0062] The hydraulic composition preferably contains a cementitious binder, preferably a mortar or concrete, and preferably contains 20-90% by weight of fine aggregate and 0.01-1% by weight of a superplasticizer, based on the dry basis of the composition. The other components of the hydraulic composition are those normally found in the manufacture of such compositions. The preparation of the liquid composition is carried out according to the knowledge of the artisan.

[0063] When the deactivator according to the invention is added to a hydraulic composition, it can be added at any stage during the preparation of the composition, which is convenient to use and does not cause mixing problems.

[0064] If the deactivator according to the invention is added to one of its components, this addition is carried out before the addition of this component to the hydraulic composition, for example, the deactivator can be added to the fine aggregate intended for the preparation of the hydraulic composition.

[0065] In this case, the fine aggregate is contacted with the deactivator by mixing during or after processing, if possible, to ensure good dispersion of the composition and obtain a homogeneously processed material. Fine aggregates with a clay content of 0.1 to 2% by weight are typically processed. The fine aggregate should be dry (water content 10% by weight or less) when processed, if possible. The fine aggregate is processed at the quarry, if possible.

[0066] In principle, any contact of the deactivating agent with the fine aggregate will ensure the deactivation of the clay contained in the fine aggregate. Generally, a contact period of a few seconds to a few minutes is sufficient.

[0067] The passivating agent is preferably used in an appropriate amount to ensure complete passivation of the fine aggregate or clay present in the hydraulic composition.

[0068] As a guideline, a dose of 2-200 ppm of deactivator based on the weight of the fine aggregate is generally sufficient to treat the fine aggregate. Professionals can adjust the dose to achieve optimal performance.

[0069] As mentioned above, the addition of a passivating agent improves clay inhibition, producing a chloride-free solution that meets code requirements and market expectations. In the long term, it reduces metal corrosion and attack on the cementitious matrix, improving the durability of structures. DETAILED DESCRIPTION OF THE INVENTION

[0070] The following examples are intended to be illustrative only and are not intended to be limiting in any way for the purposes of the present invention.

[0071] [Example] 1 / Clay deactivation polymer The polymers described in the examples are chloride-free. The process for obtaining the polymers is described below.

[0072] The acrylamide homopolymer is obtained by a solution polymerization process in deionized water. The amount of transfer agent is adjusted to give the molar mass listed in Table 1.

[0073] Homopolyvinylamine is obtained by polymerizing poly(N-vinylformamide) in aqueous solution followed by alkaline hydrolysis. The hydrolysis is quantitative.

[0074] Acrylamide / vinylamine copolymers are obtained by Hoffmann degradation of polyacrylamide in the presence of sodium hypobromite, followed by casting of polyisocyanate with an excess of acid.

[0075] The copolymer of acrylamide and N-vinylformamide can be obtained by copolymerizing acrylamide and N-vinylformamide in deionized water by solution polymerization.

[0076] Terpolymers of acrylamide, vinylamine, and N-vinylformamide can be obtained by Hoffmann degradation of copolymers of acrylamide and N-vinylformamide, as described above.

[0077] Table 1 below summarizes the compositions of the polymers synthesized.

[0078] [Table 1]

[0079] ACM: acrylamide VA: vinylamine EPI / DMA: A cationic polymer obtained by polycondensation of epichloridrin and dimethylacrylamide. DMA: dimethylacrylamide VF: vinyl formamide BA: butyl acrylate Mw: Weight average molecular weight The polymer of Example 3 contains 26% by weight chloride.

[0080] 2 / Application test Portland Le Classique cement (Lafarge, CEM II-32.5 R, Cimenterie Le Teil), standard sand (Societe Nouvelle du Littoral), and clay (bara-kade 200, Bentonite Performance Minerals LLC) are added to the mixing bowl and mixed at low speed for 15 seconds to homogenize. An aqueous solution of superplasticizer (Floset SH5) and clay inertizer is prepared and added to the cement mixture over 30 seconds while stirring at low speed. The mixture is then mixed for another 5 minutes. The water / cement ratio is 0.45. The superplasticizer mass is 0.5% by weight of cement. The sand / cement ratio is equal to 3. The amount of inert material depends on the test product and is expressed as the ratio of dry product to sand.

[0081] The paste is then poured into an inverted cone (Abrams cone) on a Plexiglas plate. When the cone is lifted, the dough spreads. The diameter (D) of the wafer is measured.

[0082] Applying the following formula, compare the diameter of the cake without clay (Dmax = 320 mm) with the diameter of the cake without inert agent (Dmin = 250 mm): Diffusivity = (D-Dmin) / (Dmax-Dmin) x 100

[0083] The closer the value is to 100%, the greater the clay's inhibitory effect.

[0084] Previously synthesized inert clay polymers were tested. For each example, the point at which performance was optimal was determined. The results are shown in Table 2 below.

[0085] [Table 2]

[0086] The inactive clay polymers of the present invention performed better than the control examples. Recovery rates without the use of a deactivator were at least 50%. Other polymers were less than 50%. Furthermore, the polymers of the present invention were more effective and allowed for significantly reduced dosages. Polyvinylamine showed excellent results, with over 60% diffusion observed at doses of 20 ppm or less. Polyvinylformamide also performed well, with a 100% spread recovery. Finally, it is noteworthy that the cationic polymer of control Example 3, which contained chloride (26% by weight), performed worse than the polymer of the present invention without chloride.

[0087] 3 / Tests on copolymers containing hydrophobic monomers The polymer of Example 4 was compared to the polymers of Examples 10 and 12. A second similar application test was performed. The polymer loading was varied and the performance was as shown in Table 3.

[0088] [Table 3]

[0089] The inert clay polymers of the present invention containing hydrophobic monomers (Ex10 and 12) offer good performance over a wider dosage range, allowing for greater flexibility in their use at the processing site, whether at the fine aggregate quarry or at the hydraulic composition manufacturing site.

Claims

1. 1. A method for deactivating clay in a hydraulic composition intended for construction, said method comprising the step of adding at least one clay deactivator to the hydraulic composition or to one of the components of the hydraulic composition, characterized in that the clay deactivator is a chloride-free, water-soluble polymer comprising acrylamide and / or vinylamine and / or vinylformamide monomer units and, optionally, monomer units of a chemical nature different from the acrylamide, vinylamine and vinylformamide monomer units, and that the clay deactivator has a weight average molecular weight between Mw L and Mw H, Mw L = [AM] ＊ 30+ [VA] ＊ 10+[VF] ＊ 10+ [MO] ＊ 20. Also Mw H=[AM] ＊ 500+[VA] ＊ 3000+[VF] ＊ 3000+[MO] ＊ 2000、 wherein [AM], [VA], [VF] and [MO] are the monomer proportions (mol %) relative to the total number of monomer units of the polymer, the monomer units being acrylamide, vinylamine, vinylformamide and units of chemical nature different from acrylamide, vinylamine and vinylformamide monomer units, the sum of [AM], [VA], [VF] and [MO] is equal to 100 mol %, and the proportion of acrylamide, and / or vinylamine, and / or vinylformamide monomer units in the water-soluble polymer is 70 mol % or more relative to the total monomer units of the polymer.

2. 2. The method of claim 1, wherein the water-soluble polymer is non-ionic.

3. The water-soluble polymer may be one of the following: - acrylamide homopolymer, homopolyvinylamine, - homopolyvinylformamide, - copolymers comprising two monomer units selected from acrylamide, vinylformamide and vinylamine; - terpolymers containing acrylamide, vinylformamide and vinylamine monomer units, a terpolymer comprising at least two monomer units selected from acrylamide, vinylformamide, and vinylamine and at least one hydrophobic monomer unit; 3. The method according to claim 1 or 2, characterized in that the compound is selected from the group consisting of:

4. 3. The method according to claim 1 or 2, characterized in that the water-soluble polymer comprises only acrylamide and / or vinylamine and / or vinylformamide monomer units, and optionally hydrophobic monomer units.

5. 3. The method according to claim 1, wherein the water-soluble polymer is selected from acrylamide homopolymer, homopolyvinylamine and homopolyvinylformamide.

6. 3. The method of claim 1, wherein the water-soluble polymer comprises hydrophobic monomer units.

7. 3. The method according to claim 1, wherein the water-soluble polymer contains 0.001 to 20 mol % of hydrophobic monomer units.

8. 7. The method according to claim 6, wherein the hydrophobic monomer is hydroxyethyl acrylate, hydroxypropyl acrylate, butyl acrylate, propyl acrylate, dimethylacrylamide, butylacrylamide.

9. The water-soluble polymer contains at least 80 mol % acrylamide monomer units, and ＊ Mw L and 0.8 ＊ 3. The method according to claim 1 or 2, characterized in that the polymer has a weight average molecular weight between Mw H.

10. The water-soluble polymer contains at least 80 mol % vinylamide and / or vinylformamide monomer units, ＊ MW L to 5 / 6 ＊ 3. The method according to claim 1 or 2, characterized in that the polymer has a weight average molecular weight between Mw H.

11. 3. The method of claim 2, wherein the nonionic water-soluble polymer is linear.

12. 3. The method according to claim 1 or 2, characterized in that the water-soluble polymer is added to the hydraulic composition or to one of the components of the hydraulic composition in a dosage of 2 to 200 ppm of inert agent relative to the weight of the fine aggregate.

13. A hydraulic construction composition comprising a fine aggregate, the fine aggregate comprising clay, at least one superplasticizer, and at least one clay deactivator, the clay deactivator being a chloride-free, water-soluble polymer comprising acrylamide and / or vinylamine and / or vinylformamide monomer units, and optionally monomer units of a chemical nature different from the acrylamide, vinylamine, and vinylformamide monomer units, the clay deactivator having a weight average molecular weight between Mw L and Mw H; Mw L = [AM] ＊ 30+ [VA] ＊ 10+[VF] ＊ 10+ [MO] ＊ 20. Also Mw H=[AM] ＊ 500+[VA] ＊ 3000+[VF] ＊ 3000+[MO] ＊ 2000、 wherein [AM], [VA], [VF] and [MO] are respectively the proportions (mol %) of monomers relative to the total number of monomer units in the polymer, the monomer units being acrylamide, vinylamine, vinylformamide and units of chemical properties different from acrylamide, vinylamine and vinylformamide monomer units, the sum of [AM], [VA], [VF] and [MO] being equal to 100 mol %, and the proportion of acrylamide, and / or vinylamine, and / or vinylformamide monomer units in the water-soluble polymer being 70 mol % or more relative to the total monomer units of the polymer.

14. 14. The composition of claim 13, wherein the composition is a mortar or concrete.

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