Composition for construction binder, system and associated process

A construction binder using a raw clay matrix and a melamine-core deflocculant polymer addresses the environmental and mechanical challenges of Portland cement by improving water management and mechanical performance, resulting in stronger, less shrinkage-prone construction materials.

FR3163936A1Pending Publication Date: 2026-01-02MATERRUP
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Patent Information

Application Number
FR2024007003
Authority / Receiving Office
FR · FR
Patent Type
Applications
Current Assignee / Owner
Filing Date
2024-06-27
Publication Date
2026-01-02

AI Technical Summary

Technical Problem

The production and use of Portland cement contribute significantly to global CO2 emissions, and the incorporation of raw clay in construction materials, while offering a lower carbon footprint, often results in increased water demand and reduced mechanical performance due to negative interactions with superplasticizers, necessitating improved mechanical properties and water management in construction binders.

Method used

A construction binder composition comprising a raw clay matrix and a deflocculant polymer with a melamine core, linked by covalent bonds, which effectively manages water demand and enhances mechanical performance, reducing shrinkage and cracking risks.

Benefits of technology

The composition achieves improved mechanical strength and reduced water demand, with enhanced early-age strength and minimized shrinkage, making it suitable for construction materials with a lower environmental impact.

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Abstract

The invention relates to a construction binder composition comprising a raw clay matrix and a deflocculating polymer comprising monomers containing a melamine core, said deflocculating polymer having a main chain comprising melamine cores linked together by covalent bonds. The invention relates to a construction binder and a construction material formed from this composition. Figure to be published with the abstract: Figure 1
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Description

Title of the invention: Composition for construction binder, system and associated method technical field

[0001] The invention relates to the field of construction and more particularly to that of construction materials and construction binders. In particular, it relates to a new composition for a construction binder. Previous technique

[0002] In 2022, cement was the second most consumed resource in the world, with over 4 billion tons produced annually worldwide. This consumption is constantly increasing, driven by the growing demand for housing and infrastructure. Cement is notably used in the manufacture of masonry elements that rely on cementitious materials as binders. The cement used in construction is generally Portland cement. It is a hydraulic binder that, when mixed with water, hardens and sets. After hardening, the cement retains its strength and stability, even when exposed to water.

[0003] Due to the constant development of new infrastructure in most countries of the world, there is a continuous demand for the supply of construction binders, particularly raw materials for the production of Portland cement. However, the production and use of Portland cement is associated with a high environmental footprint. The cement industry generates approximately 8% of global CO2 emissions. Indeed, it is estimated that the manufacture of a Portland-type construction binder generates an average of 0.8 kg of CO2 per kg of Portland cement clinker produced.

[0004] Various solutions have therefore been developed to try to replace, at least partially, certain components of the construction binders used in the production of Portland cements. These solutions primarily aim to reduce the carbon footprint. In developing these solutions, clay was avoided in construction binders or even construction materials until recently because low concentrations were sufficient to interact negatively with superplasticizers such as PCEs (Polycarboxylates) used in concrete. Thus, in concrete, raw clays were long considered an impurity introduced, for example, by aggregates (e.g., sand). A low clay content inhibits the effect of plasticizers and superplasticizers and has a negative impact on the water demand of concrete. This leads to a significant increase in the amount of water required to obtain a given flow, resulting in a loss of mechanical performance on hardened product.

[0005] However, it has been discovered that, once calcined, clays have pozzolanic properties and can also be used as a complementary cementitious material. With the aim of reducing the carbon footprint even slightly, construction materials using calcined clay have been developed. This calcined clay generally exhibits little negative interaction with the most commonly used superplasticizers, including PCE. Calcined clays are generally produced by high-temperature treatment ranging from 450 to 950°C, which results in dehydroxylation or even partial structural collapse of the clay mineral. In recent years, clay-limestone (LC3) cements have been considered among the most promising low-CO2 cements.These ternary cements allow for a reduction in clinker content of up to 50% while achieving a strength equivalent to Portland cement at 7 days, using low levels of metakaolin. However, the presence of calcined clays increases the water demand of composite cements, and generally, higher PCE dosages are required than in Portland cements. Furthermore, the calcination of clay, whether at low or high temperature, rapid or prolonged, results in energy consumption that increases the carbon footprint of the construction material (e.g., concrete) containing it.

[0006] While it was established that the presence of raw clay in concrete was detrimental, it has recently been shown that the preparation of construction binder from raw clay, added even before the addition of fillers, could allow the generation of construction materials exhibiting high levels of mechanical strength (WO22157209, EP3932886, WO20178538, WO20141285).

[0007] Since then, new materials containing a significant amount of raw clay have been under development and make it possible to achieve significantly reduced carbon footprints.

[0008] However, in the face of climate challenges, it is necessary to further improve the mechanical performance of construction materials incorporating raw clay. Furthermore, there is a need for new solutions to generate raw clay-based construction materials with improved mechanical properties, even from raw clay matrices known to be difficult to work with for multiple reasons: heterogeneity, composition, associated industrial process, etc. Summary of the invention

[0009] The invention aims to overcome these drawbacks. The following presents a simplified summary of aspects, embodiments, and selected examples of the present invention. The purpose of this summary is to provide a basic understanding of the invention. However, it does not constitute an exhaustive overview of all aspects, embodiments, and examples of the invention. Its sole purpose is to present selected aspects, embodiments, and examples of the invention in a concise form as an introduction to the more detailed description of these aspects, embodiments, and examples that follows.

[0010] The invention relates in particular to a construction binder composition comprising a raw clay matrix and a deflocculant polymer comprising monomers containing a melamine core, said deflocculant polymer having a main chain comprising melamine cores linked together by covalent bonds.

[0011] The applicant has developed a new solution involving the use of a raw clay matrix with a low concentration of a deflocculant polymer comprising monomers containing a melamine core. Indeed, the use of this type of deflocculant polymer allows for much better management of the water demand of a binder using a raw clay matrix, and therefore, even at low concentrations, makes it possible to achieve better mechanical performance values.

[0012] Furthermore, as detailed below, a composition according to the invention can reduce shrinkage and the risk of cracking of a construction material formed from this composition.

[0013] Also, certain compositions can increase the Rc at an early age (e.g., Ij). Finally, while it is known that a low clay content inhibits the effect of plasticizers and superplasticizers and has a negative impact on the water demand of concrete, in the present invention, on the contrary, the combination of uncalcined clay with certain deflocculating polymers according to the invention makes it possible to reduce the water demand.

[0014] According to other optional features of the construction binder composition according to the invention, it may optionally include one or more of the following features, alone or in combination: - It comprises at least 10% by dry weight of raw clay matrix relative to the dry weight of the composition. Preferably, it comprises at least 20%, preferably at least 30%, more preferably at least 40%, more preferably at least 95% by dry weight of raw clay matrix relative to the dry weight of the composition. - It comprises at most 5%, preferably at most 3%, by weight of said deflocculant polymer comprising monomers containing a melamine core, relative to the dry weight of the raw clay matrix, - the deflocculant polymer comprises sulfonate groups, preferably melamine rings substituted by one or more groups sulfonate. This is particularly advantageous when used with raw clay matrices, which are notoriously difficult to work with. Indeed, the melamine cores in the deflocculating polymer according to the invention can be functionalized, allowing the introduction of various functional groups that modify the physicochemical properties of the polymer. This functionalization can occur either directly on the melamine cores before their polymerization or on the already formed polymer, by exploiting the remaining reactive sites. The raw clay matrix has a LOI value greater than or equal to 8%. Indeed, a deflocculating polymer according to the invention, comprising melamine groups forming at least part of the main chain, is particularly effective on this type of raw clay matrix. The raw clay matrix has a CaO content greater than or equal to 2%, preferably relative to the dry weight of the raw clay matrix. Indeed, a deflocculating polymer according to the invention, comprising melamine groups forming at least part of the main chain, is particularly effective on this type of raw clay matrix. The raw clay matrix has a K2O content of 5% or less, preferably relative to the dry weight of the raw clay matrix. Indeed, a deflocculating polymer according to the invention, comprising melamine groups forming at least part of the main chain, is particularly effective on this type of raw clay matrix. The raw clay matrix has a Na2O content of 2% or less, preferably relative to the dry weight of the raw clay matrix. Indeed, a deflocculating polymer according to the invention, comprising melamine groups forming at least part of the main chain, is particularly effective on this type of raw clay matrix. The raw clay matrix has a SiO2 content greater than or equal to 35%, preferably relative to the dry weight of the raw clay matrix. Indeed, a deflocculating polymer according to the invention, comprising melamine groups forming at least part of the main chain, is particularly effective on this type of raw clay matrix which, in the presence of a significant amount of quartz, is generally not used for the formation of construction binders. The deflocculant polymer has a molecular weight of at least 2,000 g / mol, preferably at least 9,000 g / mol, more preferably at least 14,000 g / mol, and even more preferably at least 22,000 g / mol. These molecular weights allow for high performance. The deflocculating polymer, at a pH of 8 or higher, has at least 3 charged groups, preferably at least 3 anionic groups, preferably at least 4 anionic groups, more preferably at least 5 anionic groups, and even more preferably at least 10 anionic groups. This is particularly advantageous when used with raw clay matrices, which are known to be difficult to work with. The deflocculant polymer has a molecular weight to number of anionic groups ratio of less than or equal to 2000, preferably less than or equal to 1800, more preferably less than or equal to 1600 and even more preferably less than or equal to 1400. Indeed, this is particularly advantageous when used with raw clay matrices. The deflocculant polymer has a molecular weight to number of anionic groups ratio greater than or equal to 200, preferably greater than or equal to 220, more preferably greater than or equal to 240 and even more preferably greater than or equal to 260. Indeed, this is particularly advantageous when used with raw clay matrices. The deflocculant polymer has a polydispersity index of less than 5. Indeed, this is particularly advantageous when used with raw clay matrices. the deflocculant polymer comprises one or more poly(oxyethylene) or poly(oxypropylene) chains, the poly(oxyethylene) and poly(oxypropylene) chain(s) having a molecular mass of at least 200 g / mol, The deflocculant polymer comprises one or more side chains with at least one unsaturation, preferably at least two. This is particularly advantageous when used with raw clay matrices. Alternatively, or in combination, the deflocculant polymer comprises one or more side chains with at least one branching, preferably at least two branches. The deflocculant polymer has a ratio of at least 2:1 between the number of sulfonate functions (for example, carried by melamine sulfonate) and the number of uncharged side chains. This is particularly advantageous when used with raw clay matrices. - It contains several deflocculating polymers. It also contains polymers selected from: polycarboxylate ether, polynaphthalene sulfonate, or polyethylene oxide. - the raw clay matrix comprises at least one mineral species selected from: Illite, Kaolinite, Smectite, Bentonite, Vermiculite, Chlorite, Montmorillonites, Muscovite, Halloysite, Sepiolite, and Attapulgite, - the composition is in the dry state, for example it has a water content less than or equal to 5%.

[0015] According to another aspect, the invention further relates to a construction binder that can be made from a composition according to the invention. Preferably, a construction binder made from a composition according to the invention. More preferably, a construction binder according to the invention comprises a raw clay matrix and a deflocculating polymer comprising monomers containing a melamine core, said deflocculating polymer having a main chain comprising melamine cores linked together by covalent bonds.

[0016] According to other optional features, a construction binder according to the invention may optionally include one or more of the following features, alone or in combination: - It also contains at least 10% by weight of activator(s), relative to the dry weight of construction binder; and - It also contains at least 5% by weight of precursor(s), relative to the dry weight of construction binder.

[0017] According to another object, the invention further relates to a construction material made from a composition according to the invention or from a construction binder according to the invention.

[0018] According to another object, the invention further relates to a method for manufacturing a construction binder composition comprising a step of mixing a raw clay matrix with a deflocculant polymer comprising monomers containing a melamine core, said deflocculant polymer having a main chain comprising melamine cores linked together by covalent bonds. Brief description of the drawings

[0019] Other features and advantages of the invention will be better understood from the following description and with reference to the accompanying drawings, given by way of illustration and not limitation.

[0020] [Fig. 1] represents a schematic illustration of a process for manufacturing a composition according to an embodiment of the present invention. The steps outlined in dashed lines are optional.

[0021] [Fig. 2] represents a schematic illustration of a method for manufacturing a construction material according to an embodiment of the present invention. Description of embodiments

[0022] Below, we describe a summary of the invention and the associated vocabulary, before presenting the disadvantages of the prior art, and finally showing in more detail how the invention remedies them.

[0023] The term “binder” or “construction binder” in the context of the invention can be understood as a formulation that ensures the agglomeration of materials, particularly during the setting and subsequent hardening of a construction material. Thus, it specifically ensures the agglomeration of sand and other constituents of the construction material with the constituents of the binder. The binder according to the invention is, in particular, a hydraulic binder, meaning that hardening occurs upon contact with water.

[0024] The term "clay matrix," as used in the invention, may refer to one or more rock materials based on hydrated silicates or aluminosilicates with a lamellar structure, said clay matrix being composed of fine particles generally resulting from the alteration of silicates with a three-dimensional framework, such as feldspars. A clay matrix may thus comprise a mixture of such rock materials, such as kaolinite, illite, smectite, bentonite, chlorite, vermiculite, or mixtures thereof. Furthermore, a clay matrix may include silts.

[0025] For the purposes of this invention, the term "raw clay matrix" can refer to a clay matrix that has not undergone a calcination step. It can therefore also be called an uncalcined clay matrix. For example, this corresponds to a clay matrix that has not been subjected to a temperature rise exceeding 300°C, preferably exceeding 200°C, and more preferably exceeding 150°C. Indeed, the raw clay matrix may undergo a heating-drying step requiring a temperature rise generally equal to or less than 150°C, but no calcination step. A raw clay matrix may preferably comprise a mixture of rock materials, which may, for example, include kaolinite, illite, smectite, micas such as muscovite, bentonite, chlorite, vermiculite, or mixtures thereof, as well as silts.

[0026] In the following description, the term "% by weight" in relation to the binder composition, the binder itself, or the construction material, shall be understood as a proportion relative to the dry weight of the composition, the binder, or the construction material, respectively. The dry weight may, for example, correspond to the weight before the addition of water, for example, necessary for the Construction material formation. When % values ​​by weight are given as ranges, the bounds are included unless otherwise specified.

[0027] For the purposes of this invention, a "flocculant" can refer to a compound capable of dissociating aggregates and colloids, particularly those in aqueous suspension. Flocculant agents have, for example, been used in drilling or oil extraction to make clay more fluid and facilitate extraction or drilling. For the purposes of this invention, the term "flocculant polymer" can refer to a deflocculant agent comprising at least one monomer repeat.

[0028] The term "monomer" corresponds, in the sense of the invention, to a molecule or chemical compound that can assemble repeatedly to form a larger polymeric structure.

[0029] The term “polymer” refers, in the context of this invention, to a macromolecule composed of numerous identical monomer units chemically bonded to one another repeatedly, thus forming a large structure with a high molecular weight. For example, a polymer may comprise at least 10 monomers.

[0030] For the purposes of this invention, a "main chain," also referred to as a backbone, can correspond to the continuous sequence of covalent bonds linking the monomers together to form the polymer. This linear or sometimes branched structure constitutes the framework of a polymer, upon which the various physical, chemical, and mechanical properties of the material are based.

[0031] For the purposes of this invention, a "side chain" of a polymer can correspond to the functional groups or polymer segments that are attached to the main chain but are not an integral part of the repeating sequence of monomers constituting the main backbone. These side chains can vary in length, chemical structure, and functionality.

[0032] For the purposes of the invention, the expression "melamine core" can correspond to a molecular fragment derived from melamine, a trimeric organic compound with the molecular formula C3H6N6. Thus, a melamine core generally comprises a triazine ring that can be substituted.

[0033] For the purposes of the invention, the expression "melamine sulfonate" may correspond to a functionalized derivative of melamine where one or more sulfonate groups (-SO3-) are linked directly or indirectly to the nitrogen of the amine groups of the melamine molecule.

[0034] The terms "group", "functional group" or "chemical group" correspond to the meaning of the invention and are a set of atoms linked in a molecule which confers specific properties and reactivities to that molecule.

[0035] The term "negatively charged group" corresponds, in the sense of the invention, to a group comprising at least one atom which has at least one negative charge due to the presence of additional ions or electrons.

[0036] For the purposes of this invention, the expression "average molar / molecular mass" can refer to a statistical measurement of the average mass of molecules in a sample of a polymer. Preferably, for the purposes of this invention, the average molecular mass corresponds to the average molecular mass by weight (Mw). It is preferably measured according to the specifications of ISO 16014:2019.

[0037] The term "Portland cement" refers to a hydraulic binder composed primarily of hydraulic calcium silicates, the setting and hardening of which is achieved through a chemical reaction with water. Portland cement generally contains at least 95% clinker and a maximum of 5% secondary constituents such as alkalis (Na₂O, K₂O), magnesia (MgO), gypsum (CaSO₄ • 2 H₂O), or various traces of metals. For example, Portland cement may refer to CEMI.

[0038] The term "clinker" can refer to a constituent of cement and is obtained by firing a mixture composed of approximately 80% limestone and 20% aluminosilicates (such as clays). This firing process, clinkerization, is generally carried out at a temperature exceeding 1200°C, which is particularly energy-intensive and generates significant greenhouse gas emissions. The clinker is generally ground and then can be mixed with blast furnace slag to produce composite cements.

[0039] The term “sand” can refer to particles, resulting from the disintegration of rocks, with a size between 0.063 mm and 2 mm.

[0040] The term “silt” can refer to particles whose grain size is intermediate between clays and sands (between approximately 2 and 50 micrometers).

[0041] The term "D50" corresponds to the median diameter for which 50% (e.g., by volume, number, or mass, preferably by number) of the grains, particles, aggregates, or sediments are smaller than a given diameter. For example, if a sieving and sedimentation analysis method indicates a D50 of 5.8 mm, then 50% of the particles in the sample (by number, volume, or mass, preferably by mass) are larger than 5.8 mm. D50 is generally used to represent the particle size of a group of particles. D50 is preferably measured according to ASTM D422-63 or ASTM D6913-04(2009), or, in particular for fine particles, ISO 13320:2020 (e.g., D10 or <65 µm). The expressions "particle size property" or "particle size profile" or "particle size distribution" can correspond to parameter values ​​relating to the particle size distribution, for example in the matrix raw clay or in raw soils. There are many parameters relating to particle size distribution such as D50, D10, D90.

[0042] The term "excavated clay soil" refers, in the context of the invention, to clay soil obtained following a step in which the ground has been excavated, for example, during sediment dredging, leveling, and / or earthmoving operations, for the purpose of construction, building, or backfilling. In particular, in the context of the invention, the excavated clay soil may or may not be removed from the excavation site. Preferably, and according to an advantage of the invention, the excavated soil is used at the excavation site or at a distance of less than 500 km, preferably less than 200 km, and more preferably less than 50 km. Thus, the process according to the invention may include a step of extracting raw soil and transporting raw soil over a distance of less than 500 km before its use in the process.Furthermore, advantageously, the clay soil excavated within the framework of the invention is raw excavated clay soil, meaning that it has not undergone a calcination step. In particular, this means that it has not been subjected to any prior heat treatment. For example, this corresponds to clay soil that has not been subjected to a temperature rise exceeding 300°C, preferably exceeding 200°C, and more preferably exceeding 150°C. Indeed, raw clay soil may undergo a drying step requiring a temperature rise generally of approximately 150°C, but not a calcination step. A calcination step might, for example, correspond to a heat treatment at over 600°C for several seconds. Excavated clay soil may exhibit different particle size profiles.In the context of the invention, excavated clay soil may contain particles larger than 2 µm, preferably larger than 20 µm, preferably larger than 50 µm, and for example, larger than 75 µm, as determined according to ASTM D422-63 or ASTM D6913-04(2009). Preferably, the excavated clay soil does not contain aggregates larger than 2 cm, as determined according to NF EN 933-1, and preferably no aggregates larger than 0.5 cm. This particle size distribution can be assessed after deagglomeration and / or crushing.

[0043] The term "substantially equal" in the meaning of the invention corresponds to a value varying by less than 20% from the compared value, preferably by less than 10%, even more preferably by less than 5%.

[0044] The construction sector must evolve to optimize its productivity while addressing societal and environmental challenges. The most promising existing solutions for reducing the environmental footprint of construction materials are based on the use of a raw material with a low carbon footprint, namely raw clay. However, construction binders presenting A significant raw clay matrix content may result in lower mechanical properties than Portland cements. This is particularly true when using certain clay matrices.

[0045] In order to maximize the use of raw clay matrices and thus minimize the environmental footprint of the construction sector, the applicant developed a new solution enabling the manufacture of construction materials with high mechanical properties using a maximum amount of clay matrices, particularly those that are usually difficult to utilize. Faced with this situation, the applicant developed a new solution enabling the manufacture of construction materials based on raw clay matrices, especially those that are typically difficult to utilize.

[0046] As will be detailed later, the developed solution is based on a combined use of raw clay matrix with a particular family of deflocculant polymer, namely deflocculant polymers comprising melamine groups, said melamine groups forming at least part of the main chain of said deflocculant polymer.

[0047] Furthermore, as will be detailed later, the performance of construction materials can be further improved by particular selections of the deflocculating polymers used.

[0048] Thus, according to a first aspect, the invention relates to a composition for a construction binder. This composition comprises, in particular, a raw clay matrix and a deflocculating polymer comprising monomers containing a melamine core. The deflocculating polymer according to the invention has a main chain comprising melamine cores linked together by covalent bonds; in other words, the main chain is formed of a repeating sequence where the melamine cores are linked together by covalent bonds. As mentioned and illustrated in the examples, the composition according to the invention has the advantage of enabling the formation of construction materials based on a raw clay matrix with improved mechanical performance.

[0049] The composition according to the invention advantageously comprises at least 10% by dry weight of raw clay matrix relative to the dry weight of the composition.

[0050] The composition according to the invention can be used immediately after its formation to form a construction binder, which will in turn be used immediately after its formation to form a construction material. Alternatively, the composition according to the invention can be prepared in advance and even transported before its use.

[0051] Advantageously, the construction binder composition according to the invention is in a dry state. That is to say, it has, for example, a water content of 5% or less, preferably 2% or less, more preferably 1% or less, and even more preferably 0.1% or less. The moisture (water content) of the clay matrix can be measured as described in ISO 12570:2000. In short, the determination of the moisture content is carried out by hot drying (thermogravimetric analysis).

[0052] The following will be detailed preferred or non-preferred embodiments of the raw materials that can be implemented in the context of several aspects of the present invention.

[0053] Raw clay matrix

[0054] The raw clay matrix may, for example, comprise at least one mineral species selected from: Illite, Kaolinite, Smectite, Vermiculite, Chlorite, Montmorillonite, Muscovite, Halloysite, Sepiolite, and Palygorskite. For example, the raw clay matrix may comprise at least 5%, preferably at least 15%, and even more preferably at least 20% by weight of a mineral species selected from: Illite, Kaolinite, Smectite, Vermiculite, Chlorite, Montmorillonite, Muscovite, Halloysite, Sepiolite, and Palygorskite.

[0055] Preferably, the raw clay matrix comprises at least two types of clay selected from: Illite, Kaolinite, Smectite, Vermiculite, Chlorite, Montmorillonite, Muscovite, Halloysite, Sepiolite, Interstratified clays, Pyrophyllite, Talcs, Serpentines, and Palygorskite. This includes so-called interstratified clays, which are complex combinations of several clays. Even more preferably, the raw clay matrix comprises at least one mineral species selected from: Kaolinite, Illite, Smectite, Palygorskite, Sepiolite, Chlorite, Montmorillonite, and Vermiculite.

[0056] Table 1 below presents the chemical characteristics of these mineral species. [Tables 1] Matrix Clayey C rue Type of clay Composition Illite (K,H3O)(Al,Mg,Fe)2(Si,Al)4O10[(OH)2,(H2O)] Smectite (Na,Ca)0.3(Al,Mg)2Si4O10(OH)2, n H2O Kaolinite Al2Si2O5(OH)4 Bentonite (Na,Ca)o.3(Al,Mg)2Si4010(OH)2 Vermiculite (Mg,Ca)0.7(Mg,Fe,Al)6(Al,Si)8O22(OH)4nH2O Chlorite (Fe,Mg,Al)6(Si,Al)4O10(OH)8 Muscovite KAl2(AlSi3O10) (OH,F)2 Halloysite Al2Si2O5(OH)4 Sepiolite Mg4Si6O15(OH)2, n H2O Palygorskite (Mg,Al,Fe3+)5[Si8O20](OH)2 (OH2)4n H2O

[0057]

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[0064] According to a preferred mode, a binder composition or a construction binder according to the invention comprises at least two different types of clays and comprises smectite (Smectite, Bentonite, Montmorillonite), kaolinite, and / or illite. According to a more preferred mode, a binder composition or a construction binder according to the invention may comprise kaolinite, and / or illite. The type of clay can be determined using methods known to those skilled in the art, for example, after specific sample preparation using the oriented slide method (see Thiry et al. - 2013 - Technique for preparing clay minerals for X-ray diffraction analysis and introduction to diagram interpretation). In particular, X-ray diffractometry can be used. For example, the following conditions can be applied: - Equipment: Diffractometer, for example a BRUKER D8 ADVANCE® (Bragg-Brentano geometry); for example with the following settings: Copper Tube (X Kal ~ 1.54 Å) Generator power: 40 kV, 40 mA; Primary optics: fixed slit 0.16°; Soller slit 2.5°; Secondary optics: Soller slit 2.5°; LynXeye XE-T® detector - Acquisition parameters: Scanning from 4 to 90°20; Scanning speed of 0.03°20 / second, Counting time: 480 seconds per step; Rotating sample. The present invention is particularly suited to certain clay matrices. Indeed, within the diversity of clay matrices, the inventors have identified the characteristics of clay matrices that combine best with a deflocculating polymer comprising monomers containing a melamine core. The raw clay matrix may have a LOI (Loss on Ignition, which corresponds to the mass loss during combustion) value greater than or equal to 8%. Preferably, the raw clay matrix has an LOI value greater than or equal to 10%, more preferably greater than or equal to 12%, and even more preferably greater than or equal to %. The LOI value can be calculated using the following equation: m LAW (%) = ~7nT where mi represents the initial mass of the raw clay matrix sample before the effect of temperature (between 550°C and 1000°C) my represents the final mass of the raw clay matrix sample after the effect of temperature (between 550°C and 1000°C), for example using the ASTM D7348-21 standard.

[0065] The raw clay matrix may contain a CaO content greater than or equal to 2%. Preferably, the raw clay matrix contains a CaO content greater than or equal to 4%, more preferably greater than or equal to 6%, even more preferably greater than or equal to 8%, for example greater than or equal to 10%. The CaO content can be measured, for example, by X-ray diffraction, X-ray fluorescence spectrometry, or atomic absorption spectrometry.

[0066] The raw clay matrix may have a K2O content of 5% or less. Preferably, the raw clay matrix has a K2O content of 3% or less, more preferably 2% or less, and even more preferably 1.5% or less. The K2O content can be measured, for example, by X-ray diffraction, X-ray fluorescence spectrometry, or atomic absorption spectrometry.

[0067] The raw clay matrix may contain an amount of Na2O less than or equal to 2%. Preferably, the raw clay matrix contains an amount of Na2O less than or equal to 1.5%, more preferably less than or equal to 1%, and even more preferably less than or equal to 0.5%. The amount of Na2O is measured, for example, by X-ray diffraction, X-ray fluorescence spectrometry, or atomic absorption spectrometry.

[0068] The raw clay matrix may have a SiO2 content greater than or equal to 30%. Preferably, the raw clay matrix has a SiO2 content greater than or equal to 35%, more preferably greater than or equal to 40%, and even more preferably greater than or equal to 45%, for example greater than or equal to 48%. The SiO2 content is measured, for example, by X-ray diffraction, X-ray fluorescence spectrometry, or atomic absorption spectrometry.

[0069] The raw clay matrix may preferably correspond at least in part to excavated clay soil, preferably uncalcined excavated clay soil, such as treated raw excavated clay soil. The raw clay matrix may advantageously have been treated, such treatment being selected from: grinding, sorting, sieving and / or drying. Preferably, the raw clay matrix used in the binder composition or in the binder has been ground.

[0070] Advantageously, the raw clay matrix comprises crushed raw clay. Preferably, the raw clay matrix may have a D50 less than or equal to 500 pm, preferably less than or equal to 250 pm, more preferably less than or equal to 100 pm, or even more preferably less than or equal to 50 pm, more preferably less than 45 pm.

[0071] Furthermore, the raw clay matrix may have a D50 greater than or equal to 5 pm, preferably greater than or equal to 10 pm, more preferably greater than or equal to 15 pm, or even more preferably greater than or equal to 20 pm, or even more preferably greater than 40 pm. This helps to limit the constraints on industrial production tools dedicated to grinding.

[0072] More preferably, the raw clay matrix may have a D50 between 10 µm and 500 µm, preferably between 15 µm and 250 µm, more preferably between 20 µm and 150 µm, or even more preferably between 20 µm and 50 µm. The presence of clay ground to achieve such diameters can improve the performance of the construction binder and the construction material according to the invention.

[0073] Advantageously, the raw clay matrix may comprise at least 2% by weight of silt particles, preferably at least 4% by weight, and more preferably at least 6% by weight. For example, the raw clay matrix may comprise at most 50% by weight of silt particles, preferably at most 30% by weight, and more preferably at most 20% by weight. The silt particles are, in particular, particles having a diameter between 2 µm and 63 µm (inclusive).

[0074] The raw clay matrix may contain at least 1% by weight of sand, preferably at least 2% by weight, and more preferably at least 3% by weight. For example, the raw clay matrix may contain up to 70% by weight of sand, preferably up to 50% by weight, and more preferably up to 40% by weight. For example, the raw clay matrix may contain from 1% to 70% by weight of sand particles, preferably from 2% to 50% by weight, and more preferably from 3% to 40% by weight. The sand corresponds in particular to particles having a diameter between 63 µm (exclusive limit) and 2 mm.

[0075] Preferably, the raw clay matrix comprises clay contents, in the mineralogical sense of the term, of at least 10% by dry weight, more preferably at least 20% by dry weight, and even more preferably at least 30% by dry weight. However, a raw clay matrix comprising low clay contents in the mineralogical sense may be used. In particular, the raw clay matrix may consist of fine calcareous clay or siliceous / quartz clay comprising at least 50% by dry weight of limestone, silica, and / or quartz, preferably at least 60%, more preferably at least 70%, or even more preferably at least 80% by dry weight of limestone, silica, and / or quartz. The content of these compounds is measured by X-ray diffraction.

[0076] Advantageously, the raw clay matrix used shall have a moisture content of less than 10%, preferably less than 8%, more preferably less than 6% and preferably less than 4%. However, preferably, the raw clay matrix used will have a moisture content greater than 2%. The moisture content of the clay matrix can be measured as described in ISO 12570:2000. In short, the moisture content is determined by hot drying (thermogravimetric analysis).

[0077] As mentioned above, in the context of the present invention, the construction binder composition advantageously comprises at least 5% by weight of raw clay matrix(ies). For example, a binder composition according to the invention may comprise at least 10% by weight of raw clay matrix, preferably at least 15% by weight of raw clay matrix, more preferably at least 20% by weight of raw clay matrix, and even more preferably at least 25% by weight of raw clay matrix.

[0078] A construction binder composition according to the invention may comprise from 5% to 80% by weight of raw clay matrix(ies), preferably from 10% to 70% by weight, more preferably from 15% to 60% by weight and even more preferably from 20% to 50% by weight.

[0079] However, in one embodiment, the construction binder composition may comprise at least 80% by weight of raw clay matrix(ies). For example, a binder composition according to the invention may comprise at least 85% by weight of raw clay matrix, preferably at least 90% by weight of raw clay matrix, more preferably at least 94% by weight of raw clay matrix, and even more preferably at least 96% by weight of raw clay matrix relative to the dry weight of the composition.

[0080] Deflocculating polymer comprising monomers containing a melamine core

[0081] The presence of one or more deflocculating polymer(s) comprising melamine cores forming at least part of the main chain of said deflocculating polymer can improve the performance of the construction binder and ultimately of a construction material made from this binder.

[0082] In particular, as illustrated in the examples, the use of a deflocculant polymer according to the invention, comprising monomers containing a melamine core, said deflocculant polymer having a main chain comprising melamine cores linked together by covalent bonds; otherwise formulated, the main chain is formed of a repeating sequence where the melamine cores are linked together by covalent bonds, makes it possible in particular to improve the mechanical properties obtained, in particular the Rc at Ij and at 28j.

[0083] In addition, the presence of one or more deflocculating polymers comprising monomers containing a melamine core can reduce the shrinkage observed on construction materials; in particular, the 90-day shrinkage.

[0084] In particular, the deflocculant polymer according to the invention may have been formed, notably, from a monomer comprising a melamine group, preferably from a monomer comprising a melamine group forming at least part of the main chain of said deflocculant polymer. Thus, the deflocculant polymer has a main chain formed of a repeating sequence where the melamine nuclei are linked together by covalent bonds. This deflocculant polymer preferably consists mainly of melamine monomers that are interconnected primarily via covalent bonds formed, for example, by condensation reaction with formaldehyde. These bonds involve the formation of methylene (-CH2-) or methoxymethylene (-CH2OCH3) bridges between the melamine nuclei.

[0085] The deflocculating polymer according to the invention, comprising monomers containing a melamine core, said deflocculating polymer having a main chain formed of a repeating sequence where the melamine cores are linked together by covalent bonds.

[0086] In particular, the deflocculating polymer according to the invention, comprising monomers containing a melamine core, may include sulfonate groups and preferably melamine sulfonate groups. For example, the deflocculating polymer comprising melamine groups may have been formed, in particular, from a monomer comprising a melamine sulfonate group. Preferably, said polymer may have a structure according to the following formula:

[0087] [Chem.l]

[0088] In the context of the invention, the deflocculating polymer used, comprising monomers containing a melamine core, has a weight-average molecular weight (WAM) of at least 2,000 g / mol, preferably at least 9,000 g / mol, more preferably at least 14,000 g / mol, and even more preferably at least 22,000 g / mol. Indeed, the inventors have shown that while it has been suggested in the prior art to incorporate small polymers or organic molecules into construction binders, here, in the presence of raw clay, the deflocculating polymer comprising melamine cores forming at least part of the main chain of said deflocculating polymer preferably has high molecular weights to improve the properties of the manufactured construction material. This is particularly the case when the deflocculant polymer is a Sulfofunctionalized Melamine Formaldehyde polymer.

[0089] The average molecular mass of the deflocculant polymers used in the context of the invention can, for example, be measured according to ISO 16014:2019.

[0090] As illustrated in the examples, the deflocculating polymer comprising monomers containing a melamine core has, at a pH greater than or equal to 8, at least 3 charged groups, preferably at least 3 anionic groups. Preferably, the deflocculating polymer has, at a pH greater than or equal to 8, at least 10 anionic groups, more preferably at least 15 anionic groups, and even more preferably at least 20 anionic groups.

[0091] The number of charged groups at a given pH for a deflocculant polymer used in the context of the invention can be determined from the known chemical formula of the deflocculant polymer and the known pKa values ​​of the groups constituting it.

[0092] Furthermore, the deflocculating polymer comprising monomers containing a melamine core may have a ratio between its average molecular mass (in g / mol) and its number of anionic groups, less than or equal to 2000. Preferably, it has a ratio between its average molecular mass (in g / mol) and its number of anionic groups, less than or equal to 1800, more preferably less than or equal to 1600 and even more preferably less than or equal to 1400. This makes it possible to improve the mechanical properties of the construction material produced.

[0093] Furthermore, the deflocculating polymer comprising monomers containing a melamine core may have a molecular weight-to-anionic-group ratio greater than or equal to 200. Preferably, it has an average molecular weight (in g / mol)-to-anionic-group ratio greater than or equal to 400, more preferably less than or equal to 600, and even more preferably less than or equal to 800. This improves the mechanical properties of the manufactured construction material. This is particularly pronounced when a melamine-formaldehyde-sulfofunctionalized polymer is used.

[0094] In addition, the deflocculating polymer comprising monomers containing a melamine core may have a polydispersity index of less than 5, preferably less than 4, more preferably less than 3 and even more preferably less than 2. This makes it possible to improve the mechanical properties of the manufactured construction material.

[0095] Preferably, the deflocculating polymer used comprises a main chain formed mainly of melamine nuclei. In particular, the main chain is composed of 80% melamine groups by molecular weight. More preferably, the main chain comprises at least 10 melamine groups or nuclei, and even more preferably at least 15 melamine groups or nuclei.

[0096] It is illustrated in the examples that the presence of melamine sulfonate type groups significantly improves the behavior of raw clay in a construction binder and in particular in a composition for construction binder.

[0097] The deflocculant polymer comprising monomers containing a melamine core may also comprise one or more side chains which may improve its behavior in the presence of raw clay.

[0098] Thus, the deflocculating polymer comprising monomers containing a melamine core may further comprise one or more side chains comprising: - one or more branches or - one or more unsaturations, preferably one or more alkene functions.

[0099] In particular, the deflocculating polymer may comprise one or more poly(oxyethylene) or poly(oxypropylene) chains. Preferably, these poly(oxyethylene) and poly(oxypropylene) chains have a molecular mass of at least 200 g / mol. These side chains may have a molecular mass of at least 300 g / mol, for example, at least 500 g / mol.

[0100] The deflocculating polymer comprising monomers containing a melamine core may be a copolymer formed from at least two different monomers. At least one of the two different monomers comprises a melamine group, preferably at least one melamine sulfonate group.

[0101] It is also preferable to control the number of uncharged side chains. For example, the deflocculating polymer has a ratio of the number of sulfonate functions (for example, borne by a melamine sulfonate) to the number of uncharged side chains of at least 2:1, preferably at least 3:1, more preferably at least 4:1, and even more preferably at least 5:1.

[0102] The deflocculant is preferably used in the form of a salt. However, the invention is not limited to the deflocculants mentioned above or their salts. Any type of organic deflocculant known to those skilled in the art may be used in place of the aforementioned deflocculants.

[0103] The deflocculants usable according to the present invention can be in solid or liquid form. Advantageously, the measuring means are configured to add just the right amount of additive depending on the raw clay matrix used and, in particular, depending on the measured characteristics of the raw clay matrix.

[0104] Although the composition according to the invention comprises a deflocculating polymer having monomers containing a melamine core, it is not limited to this single presence and it may include several deflocculant polymers containing melamine groups, such as, for example, but not limited to, melamine sulfonate groups on the one hand, but also other deflocculant polymers, other polymers or other organic molecules.

[0105] Thus, preferably, the composition according to the invention comprises several deflocculating polymers.

[0106] In particular, the composition according to the invention preferably comprises at most 3% by weight of deflocculant polymer comprising monomers containing a melamine core relative to the dry weight of the raw clay matrix, preferably at most 2.5% by dry weight, more preferably at most 2% by dry weight and even more preferably at most 1.5% by dry weight or at most 1% by dry weight.

[0107] The deflocculating polymer(s) comprising monomers containing a melamine core may represent at least 0.1% by dry weight of the clay matrix. Preferably, the deflocculating agent represents at least 0.15% by dry weight of the clay matrix. More preferably, the deflocculating agent represents at least 0.2% by dry weight of the clay matrix. Even more preferably, the deflocculating agent represents at least 0.5% by dry weight of the clay matrix.

[0108] OTHER CONSTITUENTS OF THE COMPOSITION FOR CONSTRUCTION BINDER

[0109] The binder composition according to the invention may comprise, in addition to a clay matrix and a deflocculating polymer: one or more precursors, one or more activators, one or more fillers, and one or more additives such as air-entraining agents, retarders, accelerators, shrinkage-reducing adjuvants, and / or viscosity-modifying adjuvants.

[0110] In particular, the binder composition according to the invention may comprise one or more precursors, one or more activators and one or more additives.

[0111] Thus, according to another aspect, the invention relates to a construction binder that can be obtained from a composition according to the invention. In particular, it relates to a construction binder obtained from a composition according to the invention.

[0112] A construction binder according to the invention comprises, in particular, a raw clay matrix and a deflocculating polymer comprising monomers containing a melamine core, said deflocculating polymer having a main chain comprising melamine cores linked together by covalent bonds; in other words, the main chain is formed of a repeating sequence where the melamine cores are linked together by covalent bonds. The binder according to the invention exhibits, as mentioned above, improved mechanical properties.

[0113] In addition, the binder according to the invention advantageously comprises at least 10% by dry weight of raw clay matrix relative to the dry weight of the composition.

[0114] Advantageously, the binder according to the invention may further comprise at least one precursor, at least one activator and / or water.

[0115] Generally, a construction binder may also contain water. In particular, a construction binder according to the invention has a water / cement mass ratio less than or equal to 0.5.

[0116] Thus, advantageously, a construction binder according to the invention comprises one or more deflocculating polymer(s) comprising monomers containing a melamine core, said deflocculating polymer having a main chain comprising melamine cores linked together by covalent bonds; otherwise formulated, the main chain is formed of a repeating sequence where the melamine cores are linked together by covalent bonds and at least 5% by dry weight of raw clay matrix.

[0117] Alternatively, a construction binder according to the invention may comprise at least 11% by dry weight of raw clay matrix, preferably at least 15% by dry weight of raw clay matrix, more preferably at least 20% by dry weight of raw clay matrix, even more preferably at least 25% by dry weight of raw clay matrix.

[0118] A construction binder according to the invention may comprise at most 80% by dry weight of raw clay matrix, preferably at most 70% by dry weight of raw clay matrix, more preferably at most 60% by dry weight of raw clay matrix, even more preferably at most 50% by dry weight of raw clay matrix.

[0119] Generally a construction binder according to the invention can comprise from 11% to 80% by dry weight of raw clay matrix, preferably from 15% to 70% by dry weight of raw clay matrix, more preferably from 20% to 60% by dry weight of raw clay matrix, even more preferably from 25% to 50% by dry weight of raw clay matrix, relative to the dry weight of the construction binder.

[0120] The following will be detailed preferred or non-preferred embodiments of the raw materials that can be implemented in the context of several aspects of the present invention.

[0121] Precursor

[0122] A construction binder according to the present invention may comprise at least one precursor. Preferably, a construction binder may comprise at least two different precursors. In particular, it may comprise at least one calcined clay matrix. Furthermore, it may comprise a calcined clay matrix as well as another precursor.

[0123] A construction binder according to the present invention may comprise at least 5% by weight of precursor(s), preferably at least 10% by weight of precursor(s), more preferably at least 15% by weight of precursor(s), even more preferably at least 20% by weight of precursor(s), relative to the dry weight of construction binder.

[0124] A construction binder according to the present invention may comprise at most 40% by weight of precursor(s), preferably at most 35% by weight of precursor(s), more preferably at most 30% by weight of precursor(s), even more preferably at most 32.5% by weight of precursor(s), relative to the dry weight of construction binder.

[0125] Generally, a construction binder according to the present invention comprises from 5% to 40% by weight of precursor(s), preferably from 10% to 35% by weight of precursor(s), more preferably from 15% to 30% by weight of precursor(s), even more preferably from 20% to 32.5% by weight of precursor(s), relative to the dry weight of construction binder.

[0126] For example, a construction binder according to the invention may comprise at least 2% by weight of calcined clay matrix, preferably at least 3% by weight of calcined clay matrix, more preferably at least 4% by weight of calcined clay matrix relative to the dry weight of the construction binder.

[0127] A construction binder according to the present invention may comprise at most 20% by weight of calcined clay matrix, preferably at most 15% by weight of calcined clay matrix, more preferably at most 12.5% ​​by weight of calcined clay matrix, even more preferably at most 10% by weight of calcined clay matrix, relative to the dry weight of the construction binder.

[0128] Generally, a construction binder according to the present invention comprises from 2% to 20% by weight of calcined clay matrix, preferably from 3% to 15% by weight of calcined clay matrix, more preferably from 4% to 12.5% ​​by weight of calcined clay matrix, even more preferably from 4% to 10% by weight of calcined clay matrix, relative to the dry weight of the construction binder.

[0129] There are many methods for preparing a calcined clay matrix, and many different calcined clay matrices are possible. Generally, a calcined clay matrix will have undergone a calcination step at a temperature of at least 500 °C, preferably at least 600 °C. The calcination may be natural, such as for a calcined clay matrix derived from a natural pozzolanic rock. This calcined clay matrix has generally been formed from volcanic basaltic ejecta or ejecta of similar composition. However, preferably, the calcination is anthropogenic. The calcination may be a so-called flash calcination carried out over a period of less than one hour, preferably less than one minute, and more preferably less than one second (e.g., generally less than one second near a heat source exceeding 900°C after an initial temperature rise). Alternatively, the heat treatment can be carried out over several hours (e.g., at least 3 hours, preferably at least 4 hours). Heat treatments can be performed in rotary kilns, screw kilns, or calcination towers. Advantageously, the calcination equipment used is powered by decarbonized energy and / or has been retrofitted, for example, to 100% electric. Furthermore, calcination can be followed by a cooling step, for example, a cooling step of at least 3°C ​​per minute. This cooling can, for example, be achieved by quenching. Preferably, the calcined clay material is at least partially dehydroxylated.Thus, the raw, sheet-like structure is at least partially destroyed, leading to a disorganized or even amorphous structure. Furthermore, it exhibits pozzolanic activity. In particular, flash heat treatment can increase surface defects in the crystallites and thus increase the number of reactive sites. The calcined clay matrix can be formed with all the clay matrices mentioned above. Preferably, the raw clay matrix that was calcined contained kaolinite, montmorillonite, and / or illite. Therefore, preferably, the calcined clay matrix contains metakaolin, metamontmorillonite, or metallite.

[0130] A precursor may, for example, comprise slags such as blast furnace slag, steelmaking slag, or cupola furnace slag, volcanic ash, fly ash, silica fume, ash from plant materials such as rice ash, bauxite residues, calcareous fillers such as micronized calcareous fillers, silica fillers, micronized silica fillers such as glass powder, synthetic vaterite, diatomaceous earth (e.g., diatomite), ground slag, or combinations thereof. In particular, steelmaking slags may be electric arc furnace slag or oxygen converter slag.

[0131] Preferably, the precursor comprises slags such as blast furnace slags, steelworks slags, or cupola slags. More preferably, the precursor consists of slags such as blast furnace slags, steelworks slags, or cupola slags.

[0132] Preferably, the precursor comprises slags from lithium extraction or recycling processes.

[0133] Preferably, the limestone filler comprises a natural limestone mainly composed of calcium carbonate with various polymorphs, such as calcite, vaterite and / or aragonite, but which may also contain a certain amount of magnesium carbonate and / or dolomite. The limestone filler may also be a natural marl.

[0134] A precursor may, in particular, be a composition comprising at least 30% by dry weight of carbonate, calcium carbonate, or potassium carbonate, preferably at least 30% by dry weight of calcium carbonate; more preferably at least 50% by dry weight of calcium carbonate; and even more preferably at least 70% by dry weight of calcium carbonate. In this embodiment, the precursor is preferably a precursor obtained by chemical synthesis. The calcium carbonate is preferably in the form of vaterite.For example, calcium carbonate may thus comprise at least 10% by weight of vaterite; or at least 20% by weight of vaterite; or at least 30% by weight of vaterite; or at least 40% by weight of vaterite; or at least 50% by weight of vaterite; or at least 60% by weight of vaterite; or at least 70% by weight of vaterite; or at least 80% by weight of vaterite; or at least 90% by weight of vaterite; or at least 95% by weight of vaterite; or at least 99% by weight of vaterite. Vaterite, in the presence of water, forms aragonite. Vaterite can be obtained by any method known to those skilled in the art.

[0135] In particular, the precursor may be a micronized calcareous filler. That is to say, it comprises calcium carbonate in the form of particles smaller than 100 µm. Advantageously, the precursor comprises calcium carbonate present, for example, as vaterite, in the form of particles having a D50 value less than or equal to 25 µm, preferably less than or equal to 15 µm, more preferably less than or equal to 10 µm, and even more preferably less than or equal to 5 µm. The D50 measurement may be carried out by any conventional method for determining particle size, such as, but not limited to, multi-detector laser scattering, laser diffraction, or sieving. Preferably, the D50 measurement is carried out according to ISO 13320:2020.

[0136] Activator

[0137] A construction binder according to the present invention may comprise at least one activator.

[0138] Advantageously, at least one activator may be selected from an alkaline activation composition. The alkaline activation composition may preferably comprise at least one base, such as a weak base and / or a strong base. The alkaline activation composition may preferably comprise one or more compounds having a pKa greater than or equal to 8, more preferably greater than or equal to 10, more preferably greater than or equal to 12, and even more preferably greater than or equal to 14. The activation composition may be, or may comprise, lime, carbonates, cement such as Portland cement CEM I, composite cement (CEM II), blast furnace cement (CEM III / A), supersulfated or ettringitic cement, aluminous cement, and composite cement (CEM V / A) conforming to the standards NF EN 197-1 and NF EN 197-4 or to masonry cement (MC) conforming to the standard NF EN 413-1.

[0139] The activator(s) used in a construction binder according to the present invention may comprise clinker, silicates, carbonates, sulfates, gypsum (or its dehydrated forms bassanite and anhydrite), hydroxides, lactates, organophosphates, lime and their combinations.

[0140] A construction binder according to the present invention may comprise at least 10% by weight of activator(s); preferably at least 15% by weight of activator(s); preferably at least 20% by weight of activator(s), preferably at least 25% by weight of activator(s), more preferably at least 30% by weight of activator(s), even more preferably at least 35% by weight of activator(s) relative to the dry weight of construction binder.

[0141] A construction binder according to the present invention may comprise at most 60% by weight of activator(s), preferably at most 55% by weight of activator(s), more preferably at most 50% by weight of activator(s), and even more preferably at most 45% by weight of activator(s). In particular, it may comprise at most 40% by weight of activator(s), and more preferably at most 35% by weight of activator(s), relative to the dry weight of the construction binder. For example, it may comprise at most 30% by weight of activator(s) relative to the dry weight of the construction binder.

[0142] Generally, a construction binder according to the present invention can comprise from 10% to 60% by weight of activator(s), preferably from 15% to 55% by weight of activator(s), more preferably from 20% to 50% by weight of activator(s), even more preferably from 25% to 45% by weight of activator(s), relative to the dry weight of construction binder.

[0143] In particular, a construction binder according to the present invention may comprise at most 50% by weight of clinker relative to the dry weight of the construction binder, preferably at most 45% by weight of clinker relative to the dry weight of the construction binder, more preferably at most 40% by weight of clinker relative to the dry weight of the construction binder, and even more preferably at most 35% by weight of clinker relative to the dry weight of the construction binder. The clinker may advantageously be combined with gypsum to form the activator. The clinker may be used in a ground or micronized form.

[0144] The presence of clinker can be beneficial to the mechanical properties of the construction material produced with the construction binder. Thus, the construction binder according to the present invention may comprise at least 10% by weight of clinker relative to the dry weight of the construction binder, preferably at least 15% by weight of clinker relative to the dry weight of the construction binder, and more preferably, at least 20% by weight of clinker relative to the dry weight of the construction binder. The preferred option is a clinker content of at least 25% by weight relative to the dry weight of the construction binder. For example, at least 30% by weight of clinker relative to the dry weight of the construction binder.

[0145] For example, the construction binder according to the present invention may comprise from 10% to 55% by weight of clinker relative to the dry weight of the construction binder, preferably from 15% to 50% by weight of clinker relative to the dry weight of the construction binder, more preferably from 20% to 45% by weight of clinker relative to the dry weight of the construction binder, and even more preferably from 25% to 40% by weight of clinker relative to the dry weight of the construction binder. The clinker may advantageously be combined with gypsum to form the activator.

[0146] A precursor and an activator used in the context of the invention may preferably be different compounds. However, the precursor(s) and activator(s) may be added to a composition to form the building binder in the form of a single mixture comprising the precursor(s) and activator(s). This is, for example, the case when using CEM II, CEM III, CEM IV, or CEM V.

[0147] For example, the building binder may include other organic additives, for example selected from alkanolamines, glycols, glycerol, sugars, sugar acids, carboxylic acids or their salts, superabsorbent polymers, or mixtures thereof.

[0148] For example, the alkanolamines used according to the invention can be selected from monoethanolamine, diethanolamine, triethanolamine (TEA), diethanolisopropanolamine (DEIPA), ethanoldiisopropanolamine (EDIPA), isopropanolamine, diisopropanolamine, triisopropanolamine (TIPA), N-methyldiisopropanolamine (MDIPA), N-methyldiethanolamine (MDEA), tetrahydroxyethylethylenediamine (THEED), tetrahydroxyisopropylethylenediamine (THIPD), as well as mixtures of two or more of these alkanolamines.

[0149] Preferably, the alkanolamines used according to the invention can be selected from: triisopropanolamine (TIPA), N-methyldiisopropanolamine (MDIPA), N-methyldiethanolamine (MDEA), tetrahydroxyethylethylenediamine (THEED), diethanolisopropanolamine (DEIPA), tetrahydroxyisopropylethylenediamine (THIPD), as well as mixtures of two or more of these alkanolamines.

[0150] More preferably, an organic additive may further comprise alkanolamines selected from triethanolamines such as triisopropanolamine (TIPA), triethanolamine (TEA), and / or diethanolisopropanolamine (DEIPA).

[0151] Examples of glycols suitable for the organic additive are monoethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, polyethylene glycol (e.g., PEG 200), neopentyl glycol, hexylene glycol, propylene glycol, dipropylene glycol, and polypropylene glycol. It is also possible to use mixtures of two or more different glycols as well as at least one glycol and glycerol.

[0152] Examples of sugars that can be incorporated into the organic additive used during milling include monosaccharides and disaccharides. Suitable examples include allose, altrose, arabinose, cellobiose, chitobiose, fructose, galactose, glucose, glyceraldehyde, gulose, idose, isomaltose, lactose, lactulose, lyxose, maltose, mannobiose, mannose, palatinose, raffinose, ribose, sucrose, sorbose, tallose, threose, trehalose, xylose, xylobiose, and mixtures thereof.

[0153] In the context of the present invention, a "sugar acid" is a monosaccharide possessing a carboxyl group. Examples of sugar acids useful in the context of the present invention include, but are not limited to, ascorbic acid, galacturonic acid, gluconic acid, glucuronic acid, glyceric acid, iduronic acid, mucic acid, neuramine, saccharic acid, tartaric acid, and xylonic acid. The sugar acid may be in the form of a free acid or a salt.

[0154] Carboxylic acids that can be used in the organic additive in combination with the deflocculating polymer and are particularly preferred are oxalic acid, malonic acid, adipic acid, lactic acid, citric acid, and tartaric acid. The carboxylic acid may be in the form of a free acid or as a salt.

[0155] According to some embodiments, the sugar acid salts and / or carboxylic acid salts may be salts with metals from groups Ia, Ia, Ib, IIb, IVb, VIIIb of the periodic table of elements. Preferred sugar acid salts and / or carboxylic acid salts are salts of alkali metals, alkaline earth metals, iron, cobalt, copper, or zinc.

[0156] Examples of superabsorbent polymers useful in the context of the present invention include, but are not limited to, natural polymers such as starch, cellulose (including cellulose ether), chitin or collagen, alginates, and synthetic polymers such as poly(hydroxyethyl methacrylate), poly(ethylene glycol) or poly(ethylene oxide) or ionic synthetic polymers such as polyacrylic acid (PAA), polymethacrylic acid (PMAA), polyacrylamides (PAM), polylactic acid (PLA), polyethyleneimine, polyvinyl alcohol (PVA) or polyvinylpyrrolidone.

[0157] Superabsorbent polymers particularly suitable within the framework of the present invention are ionic superabsorbent polymers, in particular those based on polyacrylamide modified with acrylic acid, which can be of linear or cross-linked structure.

[0158] Thus, according to another aspect, the invention relates to a construction material obtained from a composition according to the invention and more particularly from a construction binder according to the invention.

[0159] In particular, the present invention relates to a construction material characterized in that it comprises a raw clay matrix and a deflocculant polymer comprising monomers containing a melamine core, said deflocculant polymer having a main chain formed of a repeating sequence where the melamine cores are linked together by covalent bonds.

[0160] Preferably, the construction material comprises at least 10% by dry weight of raw clay matrix relative to the dry weight of the construction binder and at most 0.5% by weight of deflocculant polymer comprising monomers containing a melamine core, said deflocculant polymer having a main chain comprising melamine cores linked together by covalent bonds; otherwise formulated, the main chain is formed of a repeating sequence where the melamine cores are linked together by covalent bonds, relative to the dry weight of the raw clay matrix.

[0161] Aggregates

[0162] A construction material according to the present invention may comprise aggregates.

[0163] Classically, aggregates can correspond to natural aggregates, artificial aggregates or recycled aggregates.

[0164] Aggregates may also include mineral aggregates, i.e., mainly composed of mineral matter, and / or plant aggregates, i.e., mainly composed of matter of plant origin. Aggregates may also include marine aggregates, i.e., mainly composed of organic or inorganic matter from the seabed, such as siliceous aggregates and / or calcareous substances (e.g., maerl and shell sands).

[0165] Mineral aggregates can, for example, correspond to sand, gravel, pebbles, fillers (or fine materials), powders, fossilized waste and combinations thereof.

[0166] Plant aggregates may, for example, consist of wood (chips or fibers), hemp, straw, hemp shives, miscanthus, sunflower, cattail, maize, flax, rice husks, wheat husks, rapeseed, seaweed, bamboo, cellulose wadding, defibrated fabric and combinations thereof

[0167] In particular, when the construction material according to the invention comprises plant aggregates, said material preferably comprises at least 0.1% by weight of plant aggregates, preferably at least 0.2% by weight of plant aggregates, of preferred method at least 0.5% by weight of plant aggregates, and even more preferred method at least 0.7% by weight of plant aggregates.

[0168] According to another aspect, the invention relates to a method for manufacturing 100 of a composition for construction binder according to the invention.

[0169] In some cases the construction binder will be directly incorporated into a construction material. In other uses, a construction binder composition can be prepared extemporaneously.

[0170] The manufacturing process 100 according to the invention can be implemented with devices or systems commonly used for the manufacture of construction binders or construction materials.

[0171] As illustrated in [Fig.1], the manufacturing process 100 according to the invention comprises a step of mixing 130 a raw clay matrix with a deflocculant polymer comprising monomers containing a melamine core, said deflocculant polymer having a main chain formed of a repeating sequence where the melamine cores are linked together by covalent bonds.

[0172] In addition, the manufacturing process 100 may include the following steps: a step of acquiring 110 the characteristic values ​​of the raw clay matrix, a step of processing 120 the raw clay matrix, a step of adding additives 140.

[0173] The manufacturing process 100 according to the invention may include a step 110 for acquiring characteristic values ​​of the raw clay matrix. An analysis step 110 may employ an analyzer. An analyzer may be selected from: a spectrometer (infrared, NMR, Raman, X-ray fluorescence, mass spectrometer), an X-ray diffractometer, a microscope (transmission, scanning), and / or other optical sensors. In particular, this step may include measuring the LOI value and / or the contents of Al₂O₃, CaO, Fe₂O₃, K₂O, MgO, Na₂O, SiO₂, SO₃, TiO₂ in the raw clay matrix. Specifically, this may include measuring the contents of CaO, K₂O, and / or Na₂O in the raw clay matrix or measuring the LOI value of the raw clay matrix.

[0174] Measurement step 110 may also include the use of conventional methods for studying particle distribution. These may include the use of sieves and sedimentation (e.g., hygrometer, pipette method) and be carried out, for example, following the instructions in ASTM D422-63, ASTM D6913-04, ISO 13320:2020, NF X31-107 and possibly NF EN 933-1.

[0175] The acquisition step 110 can be followed by a step adapting the amount of deflocculating polymer used or its molecular structure. This generally improves the performance of the resulting construction binder by taking into account the characteristics of the raw clay matrix. This can increase the mechanical strength of the resulting construction binder.

[0176] As illustrated in [Fig.1], the manufacturing process 100 according to the invention may include a treatment step 120 of the raw clay matrix.

[0177] As illustrated in [Fig. 1], the manufacturing process 100 according to the invention may include a treatment step 120 of the raw clay matrix. In particular, the treatment step 120 of the raw clay matrix may include a modification of the contents of the different particle size fractions of the raw clay matrix.

[0178] The treatment step 120 generally allows the raw material to be prepared in such a way that the construction binder has a reduced curing time and improved mechanical performance.

[0179] In particular, the raw clay matrix may advantageously have been pretreated. Preferably, the pretreatment is selected from: grinding, sorting, sieving and / or drying of the clay matrix. Preferably, the pretreatment is selected from: grinding, sorting, sieving and / or drying of the raw clay matrix. The pretreatment may, for example, include fractionation.

[0180] The treatment step 120 can generally be carried out with lump breakers, dryers, screens, and / or crushers.

[0181] Drying can, in particular, allow a reduction in the moisture content of the raw clay matrix without raising the temperature above 500°C. The dryer can, for example, be selected from a rotary dryer.

[0182] The dried raw clay matrix can advantageously undergo a screening step, for example, within a screen. This step will preferably remove aggregates with a diameter greater than or equal to 2 cm, and more preferably those with a diameter greater than or equal to 1 cm. The screen can, for example, be selected from a rotary screen.

[0183] Grinding can, for example, be carried out using a hammer mill, a ball mill, or a rod mill. As will be detailed, the grinding can be performed in such a way as to control the D50 of the materials used.

[0184] Preferably, during the formation of the composition for construction binder, the raw clay matrix may have a D50 less than or equal to 200 qm, preferably less than or equal to 150 qm, more preferably less than or equal to 100 qm, even more preferably less than or equal to 80 qm.

[0185] A manufacturing process 100 according to the invention comprises a step of mixing 130 a raw clay matrix with a deflocculant polymer comprising monomers containing a melamine core, said deflocculant polymer having a main chain comprising melamine cores linked together by covalent bonds; otherwise formulated, the main chain is formed of a repeating sequence where the melamine cores are linked together by covalent bonds.

[0186] In particular, this mixing step 130 can be carried out a few moments before the use of the construction binder composition and its mixing with the other constituents of the construction binder. Alternatively, the mixing step 130 can be carried out much earlier, and the construction binder composition thus prepared is kept dry for later mixing with other components of the construction binder or aggregates. Preferably, the process according to the invention uses a binder composition prepared extemporaneously. Alternatively, the process according to the invention uses a binder prepared at least 6 hours, preferably at least 24 hours, before its use and, for example, at another site.

[0187] The mixing step 130 can generally be carried out with a mixing device such as a mixer or blender, for example a powder blender.

[0188] In particular, as detailed later, the mixing step 130 may include the use of hoppers, weighing means, volumetric dosing means, conveying means such as augers and / or aerodynamic systems, mixer and / or blender.

[0189] The mixing step 130 is generally carried out over a sufficient period to create an intimate mixture between the different components of the binder composition. The parameters for achieving such a result may vary depending on the components of the binder.

[0190] The mixing step 130 may include mixing the constituents of the binder composition for at least 5 seconds, preferably for at least 10 seconds, more preferably for at least 20 seconds, and even more preferably for at least 30 seconds. The mixing will generally take place over a period of 20 minutes or less, preferably for no more than 15 minutes, more preferably for no more than 10 minutes, and even more preferably for no more than 5 minutes.

[0191] In particular, the mixing step 130 can be carried out in several substeps. For example, initially, the mixing process 130 may include a premixing of a raw clay matrix and an activation composition, preferably an alkaline activation composition. Furthermore, during this premixing, the process according to the invention may advantageously include the addition of a calcined metal oxide composition. Preferably, this premix is ​​not hydrated. Finally, the deflocculating polymer according to the invention, comprising monomers containing a melamine core, said deflocculating polymer having a main chain formed of a repeating sequence in which the melamine cores are linked together by covalent bonds, may be added, for example, in powder form. Alternatively, the mixing process 230 may include a premixing of a raw clay matrix and an activation composition, preferably an alkaline activation composition before the addition of the deflocculating polymer.

[0192] A manufacturing process 100 according to the invention includes a step of adding additives 140. The additives are, for example, those described in connection with the composition for construction binder.

[0193] According to another aspect, the invention relates to a method for manufacturing 200 of a construction material according to the invention.

[0194] The manufacturing process 200 according to the invention can be implemented with devices or systems commonly used for the manufacture of construction binders or construction materials.

[0195] As illustrated in [Fig.2], the manufacturing process 200 of a construction material according to the invention comprises the following steps: a step of forming the construction binder 210 and a step of adding 230 aggregates.

[0196] In addition, the manufacturing process 200 of a construction material according to the invention may include a step of adding 220 water.

[0197] The construction binder formation step 210 can be carried out using the construction binder composition. Alternatively, the construction binder composition can be prepared during the construction binder formation process. EXAMPLES

[0198] The invention is described in more detail below with reference to the following experimental examples. These examples are provided for illustrative purposes only and are not intended to be limiting unless otherwise stated. Thus, the invention should in no way be interpreted as being limited to the following illustrative examples, but rather as encompassing all the variations that become evident as a result of the teaching provided herein.

[0199] Comparative deflocculant polymer

[0200] For comparison purposes, commercially available comparative polymers are used.

[0201] In particular, the following polymers may be used: - A: [3-naphthalene sulfonate formaldehyde CAS No.: 9084-06-4 B: Poly(AMPS), CAS number: 27119-07-9 - C: Poly(sodium 4-styrenesulfonate) CAS number: 28210-41-5 - MW75000 - D: PCE (Polycarboxylate) type polymer - MW75000

[0202] Depending on their physicochemical properties, these comparative polymers are diluted in a suitable solvent or used in the dehydrated state.

[0203] Synthesis of comparative PCE polymers

[0204] The synthesized PCE (Polycarboxylate) type polymers are composed of a main chain bearing -COO carboxylate functions and onto which polyethylene glycol type secondary chains can be grafted.

[0205] PCE polycarboxylates are synthesized by radical polymerization from acrylic monomers such as acrylic acid and a methacrylic ester of poly(ethylene glycol) methoxy. Classically, the synthesis comprises three distinct steps: initiation, propagation, and termination. The radical reaction is initiated from a free radical, called the initiator, which reacts with an acrylic acid to form an acrylic radical. In a flask, acrylic acid is mixed with a peroxide (initiator). During propagation, the free acrylic radical reacts with another monomer to form a dimer radical, which then reacts again with a monomer to form a trimer radical, and so on. During termination, the polymerization chain reaction is stopped by means of a regulator.

[0206] Synthesis of deflocculating polymers comprising melamine cores forming the main chain

[0207] Deflocculating polymers comprising melamine groups can be formed by condensation between formaldehyde and a substituted or unsubstituted melamine. This makes it possible to form a deflocculating polymer comprising a main chain formed by a chain of melamine groups or nuclei.

[0208] In particular, deflocculating polymers comprising monomers containing a melamine core, said deflocculating polymer having a main chain formed of a repeating sequence where the melamine cores are linked together by covalent bonds, can be formed by condensation between formaldehyde and melamines through three steps: - Fixation of methoxyl groups -CH2OH onto amine groups -NH2 of melamine by reaction with formaldehyde in an alkaline medium. Preferably, at pH 8-10; - Fixation of sulfonates. This is carried out by the addition of sodium bisulfite in an alkaline medium. The sulfonation of only one of the methoxyl groups occurs when one mole of sulfonate is added per mole of melamine at pH=10; - Condensation polymerization. Condensation can be stopped at a degree of polymerization n between 4 and 25, corresponding to an average molecular mass of 2,000 to 25,000 g.mol1. Condensation is preferably carried out at pH 5-6 and 80°C followed by neutralization, for example by the addition of NaOH, in order to generate a deflocculating polymer mixture with a slightly basic pH.

[0209] Characterization of the clay matrix

[0210] The raw clay matrix is ​​analyzed by X-ray fluorescence according to the indications of standards NF EN 196-2 and NF EN 15309

[0211] X-ray fluorescence tests on compressed beads or pellets are carried out to determine the chemical composition of a sample, i.e., to quantify its major elements and possibly its trace elements. The samples analyzed have a particle size < 1 mm and are dried. The dried clay matrix is ​​then formed into a bead or pellet.

[0212] The results obtained in percentage of oxides concern the major elements: Al, Ca, Cr, Fe, K, Mg, Na, P, Pb, Si, Ti, V and W. The loss on ignition (LOI) measured during the preparation of the samples makes it possible to predict the potential presence of organic matter, carbonates and / or sulfates, which are elements that can be impactful.

[0213] Preparation of the clay matrix

[0214] The clay matrix is ​​screened and sieved to 10 mm. The clay matrix is ​​then crushed, for example, by a blade mill at 1200 rpm. Elements larger than 2 mm are removed.

[0215] The moisture content of the clay is measured as described in ISO 12570:2000.

[0216] In order to illustrate the effect of clay matrix typologies on the properties Mechanical properties of construction binders, two clay matrices (Al and A2) are used and their properties (in %) are presented in Table 2 below. [Tables 2] Matrix Arg ilous LOI A12O 3 CaO Fe2O 3 k2o MgO Na2O SiO 2 so3 TiO 2 Al 7.89 11.7 6.1 10.2 1.89 6.5 2.03 49.05 3.4 1.24 A2 12.12 9.4 10.1 7.3 1.56 4.33 1.24 48.51 4.5 0.94

[0217] Methodology for measuring the mechanical properties of construction binders

[0218] The construction binders described in Table 2 above are prepared in test specimens and their mechanical strength is measured at different times.

[0219] Mechanical resistance of a test specimen means its resistance to compression, such compression being measured according to standard NF EN 771-3+A1 / CN and is expressed in Mega Pascal (MPa).

[0220] Withdrawal calculation

[0221] Shrinkage is calculated according to the cement test standard from NF EN 197-1, the classic method for cements, and carried out on standardized mortar.

[0222] Preparation of a composition for construction binder

[0223] A dry premix is ​​carried out between a prepared raw clay matrix and a deflocculating polymer according to the invention in predetermined quantities.

[0224] Preparation of a construction binder and then of a material for construction binder

[0225] The premixed composition described above is combined in a mixer with blast furnace slag and an activator (e.g., clinker) and water. The mixtures are prepared such that the construction binder comprises 40% by weight of prepared raw clay matrix; 25% by weight of blast furnace slag; 35% by weight of CEM I (a mixture of 95% clinker and 5% gypsum on average).

[0226] Alternatively, the preparation of the composition is directly followed by the preparation of the binder. In this case, a dry premix is ​​carried out between a prepared raw clay matrix and a deflocculating polymer according to the invention in predetermined quantities, then the slag, CEM I / Portland cement and water are added.

[0227] The mixture is blended at a low speed, approximately 60 revolutions per minute, for 30 seconds. Then, sand is added and the mixture is blended at a higher speed, approximately 120 revolutions per minute, for one minute. The water-to-dry-matter mass ratio of the construction binder is adjusted to a value between 0.4 and 0.6. In one particular example, the construction material, a mortar, comprises 25% by weight of binder and 75% by weight of sand; this mixture is then supplemented with water to achieve a water-to-dry-matter mass ratio of 0.45.

[0228] The mortar made from the construction binder thus produced is then poured into a mold and left to cure at room temperature, i.e., about 20 degrees Celsius, for 28 days in water. Alternatively, the mortar can be poured into a mold and then left to cure for less than 24 hours in a curing stage, at room temperature, i.e., about 25 degrees Celsius, or preferably under heat treatment. During this curing stage, the mold can be sealed or the top layer of the construction material can be coated with a curing compound to limit / prevent evaporation.

[0229] Table 3 below presents, for different formulations of construction binders including five comparative formulations (REF0, REF1, REF2, REF3, REF4) and two formulations according to the invention (D1, D2). [Tables 3] Composition Name Polymer Amount of deflocculant polymer Raw clay matrix used REF0-A1 na (no deflocculant polymer) 0% Al REF0-A2 na (no deflocculant polymer) 0% A2 REF1 - Al A - Polynaphthalene sulfonate 3% Al REF2-A1 B - Poly(AMPS) 3% Al REF3-A1 C - Poly(sodium 4-styrenesulfona te) 3% Al REF4-A1 D-PCE 3% Al REF1- A2 A - Poly naphthalene sulfonate 3% A2 REF2- A2 B - Poly(AMPS) 3% A2 REF3- A2 C - Poly(sodium 4-styrenesulfona te) 3% A2 REF4- A2 D-PCE 3% A2 DI - Al PMS - 6,000 g / mol 3% Al D2-A2 PMS - 9,000 g / mol 3% A2

[0230] Methodology for measuring the mechanical properties of construction binders:

[0231] Once curing is complete, the mechanical strength is measured. The mechanical strength of a construction binder is understood to be its compressive strength, such compression being measured according to standard NF EN 196-1, for a prism with sides of 40 millimeters and a length of 160 millimeters and is expressed in Mega Pascals (MPa).

[0232] Comparison of construction binders according to the invention with known construction binders

[0233] Table 4 below presents the results of the mechanical resistances at 1 day and at 28 days as well as the shrinkage at 90 days according to the formulations detailed in Table 2. [Tables 4] ID Rclj (MPa) Rc 28j (MPa) Shrinkage 90j (mm) REF0-A1 <10 <25 < -2200 REF1 - Al <12 25 <X<45 > -2200 & <-2000 REF2-A1 <12 25 <X<45 > -2200 & <-2000 REF3-A1 <12 25 <X<45 > -2200 & <-2000 REF4-A1 <12 25 <X<45 > -2200 & <-2000 Dl- Al >12 >45 > -1800 REF0- A2 <10 <20 < -2800 REF1- A2 <10 20 <X<35 > -2800 & <-2000 REF2- A2 <10 20 <X<35 > -2800 & <-2000 REF3- A2 <10 20 <X<35 > -2800 & <-2000 REF4- A2 <10 20 <X<35 > -2800 & <-2000 D2 - A2 >12 >50 >-1000

[0234] If we compare the mechanical properties of the construction material prepared in the absence of deflocculant (REFO) and in the presence of deflocculant (REF1, REF2, REF3, REF4, Dl, D2), Table 4 above illustrates that the presence of the tested deflocculants (especially for references Dl and D2) brings an improvement for the two clays tested (Al and A2) mainly at 28 days.

[0235] Comparison of deflocculants D1 and D2, compared with other references, shows improved mechanical properties at 1 and 28 days.

[0236] Comparison of the performance of deflocculants according to clays illustrates that deflocculant 2 (D2) improves the mechanical properties of the construction material for clay 2.

[0237] The improvement provided by the deflocculant 2 is particularly strong on clay 2. Indeed, while the reference deflocculants are only slightly effective for clay 2, the deflocculant according to the invention makes it possible to produce, in combination with clay 2, a construction material having very good mechanical properties.

[0238] In addition, the deflocculants D1 and D2 exhibit a lower 90j shrinkage than the other formulations.

[0239] The study of formulations according to the present invention illustrates that the combined use of a raw clay matrix with a melanimine-based deflocculant makes it possible to achieve mechanical strength values ​​at 28 days greater than 45 MPa while maintaining a shrinkage at 90 days less than 1800 mm (for Al and A2 clays).

[0240] The invention can be the subject of numerous variations and applications other than those described above. In particular, unless otherwise indicated, the various structural and functional features of each of the embodiments described above should not be considered as combined and / or closely and / or inextricably linked to one another, but rather as mere juxtapositions. Furthermore, the structural and / or functional features of the various embodiments described above may be the subject, in whole or in part, of any different juxtaposition or any different combination.

Claims

Demands

1. Construction binder composition comprising a raw clay matrix and a deflocculant polymer comprising monomers containing a melamine core, said deflocculant polymer having a main chain comprising melamine cores linked together by covalent bonds.

2. Construction binder composition according to claim 1, characterized in that it comprises at least 10% by dry weight of raw clay matrix relative to the dry weight of the composition.

3. Construction binder composition according to claim 1 or 2, characterized in that it comprises at most 3% by weight of said deflocculant polymer comprising monomers containing a melamine core, relative to the dry weight of the raw clay matrix.

4. Construction binder composition according to any one of claims 1 to 3, characterized in that the deflocculating polymer comprises sulfonate groups, preferably melamine nuclei being substituted by one or more sulfonate groups.

5. Construction binder composition according to any one of claims 1 to 4, characterized in that it comprises at least 20%, preferably at least 30%, more preferably at least 40%, more preferably at least 95% by dry weight of raw clay matrix relative to the dry weight of the composition.

6. Construction binder composition according to any one of claims 1 to 5, characterized in that the raw clay matrix has a LOI value greater than or equal to 8%.

7. Construction binder composition according to any one of claims 1 to 6, characterized in that the raw clay matrix has an amount of CaO greater than or equal to 2%.

8. Construction binder composition according to any one of claims 1 to 7, characterized in that the raw clay matrix has a quantity of K2O less than or equal to 5%.

9. Construction binder composition according to any one of claims 1 to 8, characterized in that the raw clay matrix has an amount of Na2O less than or equal to 2%.

10. Construction binder composition according to any one of claims 1 to 9, characterized in that the raw clay matrix has an amount of SiO2 greater than or equal to 35%.

11. Construction binder composition according to any one of claims 1 to 10, characterized in that the deflocculant polymer has a molecular mass of at least 2,000 g / mol, preferably at least 9,000 g / mol, more preferably at least 14,000 g / mol and even more preferably at least 22,000 g / mol.

12. Construction binder composition according to any one of claims 1 to 11, characterized in that the deflocculating polymer has, at a pH greater than or equal to 8, at least 3 charged groups, preferably at least 3 anionic groups.

13. Construction binder composition according to any one of claims 1 to 12, characterized in that the deflocculant polymer has a molecular weight to number of anionic groups ratio less than or equal to 2000.

14. Construction binder composition according to any one of claims 1 to 13, characterized in that the deflocculating polymer has a molecular weight to number of anionic groups ratio greater than or equal to 200.

15. Construction binder composition according to any one of claims 1 to 14, characterized in that the deflocculant polymer comprises one or more poly(oxyethylene) or poly(oxypropylene) chains, the poly(oxyethylene) or poly(oxypropylene) chain(s) having a molecular mass of at least 200 g / mol.

16. Construction binder composition according to any one of claims 1 to 15, characterized in that the raw clay matrix comprises at least one mineral species selected from: Illite, Kaolinite, Smectite, Bentonite, Vermiculite, Chlorite, Montmorillonites, Muscovite, Halloysite, Sepiolite, and Attapulgite.

17. Construction binder composition according to any one of claims 1 to 16, characterized in that it is in the dry state, for example it has a water content less than or equal to 5%.

18. Construction binder made from a composition according to any one of claims 1 to 17.

19. Construction material manufactured from the construction binder according to the preceding claim.

20. A process for manufacturing a construction binder composition comprising a step of mixing a raw clay matrix with a deflocculant polymer comprising monomers containing a melamine core, said deflocculant polymer having a main chain comprising melamine cores linked together by covalent bonds.

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