Low carbon building binders and materials for summer comfort

Abstract

The invention relates to a method (100) for producing a precast element and to a construction binder comprising a raw clay base, an anti-flocculating agent and an activation component, wherein: - the raw clay base comprises at least one raw clay from the smectite group; - the at least one raw clay from the smectite group represents at least 20% by weight of the construction binder; and - the construction binder comprises less than 15% by weight of Portland cement.

Description

Technical Field

[0001] This invention relates to the field of building materials, and more specifically to the field of adhesives that can be used in construction. The invention relates to a formulation for a building adhesive. It also relates to a method for preparing a building adhesive, the building adhesive itself, and the use of such an adhesive in the production of building materials. The building materials thus obtained (which are also the subject of this invention) provide summer comfort (e.g., passively regulating humidity and heat) for the buildings incorporated into them. Background Technology

[0002] Cement is the world's second most consumed resource, with more than 4 billion tons of the material produced globally each year, and this consumption is increasing as demand for housing and infrastructure grows.

[0003] Cement is typically a hydraulic binder that hardens and solidifies when mixed with water. Once hardened, cement retains its strength and stability even when exposed to water. Many types of cement are used worldwide. However, all conventional cements include clinker, the percentage of which ranges from 5% for some blast furnace cements to as low as 95% for Portland cement, which is the most widely used cement in the world today.

[0004] Clinker is obtained by firing a mixture of approximately 80% limestone and 20% aluminosilicates (such as clay). This firing, or clinkerization, typically takes place at temperatures exceeding 1200°C, making this cement production process energy-intensive. Furthermore, the chemical conversion of limestone to lime releases carbon dioxide. Therefore, the cement industry accounts for approximately 8% of global CO2 emissions. To address this challenge, industry professionals and researchers are investigating the possibility of reducing the impact of carbon dioxide emissions from the cement industry.

[0005] To reduce carbon dioxide emissions associated with the construction sector, new low-carbon building adhesive formulations have been proposed, including raw clay matrices and antiflocculators (WO2020141285). However, this document primarily describes the use of compositions that allow for reduced carbon dioxide emissions from building materials while possessing high mechanical strength. A method for selecting the composition of building materials comprising excavated clay soil (WO2020178538), or adhesives containing at least one type of virgin clay, is also proposed, allowing for the achievement of desired properties in adhesion via traction (FR3084357) for tile adhesives.

[0006] In addition to reducing carbon dioxide emissions, consumers can also benefit from alternatives to Portland cement, which has a humid and hot nature and can provide comfort for residents during hot periods.

[0007] The extensive use of air conditioning, heating units, or other air recirculators or ventilation systems in buildings to control temperature or humidity levels also generates significant CO2 emissions (both for their manufacture and throughout their use). In contrast, by definition, passively controlling temperature or humidity levels consumes no energy and requires no human supervision. Therefore, in many cases, it represents a more resilient and sustainable option where energy consumption for heat, humidity, or more generally, ventilation and conditioning systems can be reduced.

[0008] However, the construction industry has not yet explored this area, and the rare building materials that are considered to provide comfort in summer due to their humid and hot properties are those that are not highly industrialized and are based on biological sources, such as wood (fragments, fibers), hemp (hemp shives, hemp fiber bundles), straw, or other geo-derived materials, such as soil-based materials (rammed earth, clay bricks, cob, etc.).

[0009] In particular, the use of hemp in the production of mortars, coatings, and precast hemp concrete components offers not only highly satisfactory insulation properties but also allows for optimal humidity control, and its production exhibits a very attractive carbon balance. On the other hand, bio-based building materials typically possess relatively weak mechanical properties, limiting their use in insulation, cladding, or the formation of wall panels with minimal mechanical stress. Furthermore, the relatively long drying time of hemp concrete, for example (e.g., more than 5 days), further restricts its application.

[0010] Therefore, there is a need for new formulations of fast-setting building binders that, on the one hand, have a low carbon footprint and mechanical properties at least equal to or even better than those of concrete derived from cement commonly used in the construction industry (e.g., cement CEM I, CEM I, CEM III, CEM IV and CEM V as defined by standard NF EN 197-1), and on the other hand, allow for the passive regulation of temperature and humidity in buildings incorporating such building binders.

[0011] Technical issues

[0012] The object of this invention is to overcome the shortcomings of the prior art. In particular, the object of this invention is to provide a building adhesive that allows for the production of building materials capable of heat and moisture regulation while maintaining mechanical properties adapted to the constraints of modern construction. Furthermore, the object of this invention is to provide such materials for certain applications, which also offer rapid setting.

[0013] Furthermore, the object of the present invention is to provide a method for manufacturing building adhesives that allows for the reduction of greenhouse gas emissions, such as carbon dioxide emissions during the preparation of such building materials, while maintaining the appropriate mechanical properties of the materials and imparting them with thermo-hygroscopic properties. Summary of the Invention

[0014] To address these shortcomings, the inventors have developed several solutions that allow for overcoming the limitations of existing technologies. Preferred solutions are detailed below.

[0015] This invention particularly relates to a building adhesive comprising a raw clay matrix, an antiflocculating agent, and an activating component (composition), characterized in that:

[0016] - The raw clay matrix includes at least one type of raw clay from the smectite family;

[0017] - The at least one type of raw clay from the montmorillonite family constitutes at least 20% by weight of the building adhesive; and

[0018] - The building adhesive contains less than 15% Portland cement by weight.

[0019] In particular, the present invention relates to a building adhesive comprising a raw clay matrix, an antiflocculating agent, and an alkaline activating component, characterized in that:

[0020] - It contains 2% to 40% dry weight of alkaline activating components;

[0021] It comprises at least 40% by weight of a raw clay matrix, and said raw clay matrix includes at least one type of raw clay from the montmorillonite family; said at least one type of raw clay from the montmorillonite family accounts for at least 20% by weight of the building binder; and

[0022] - The building adhesive contains less than 15% Portland cement by weight.

[0023] As will be presented in the embodiments, the building binder according to the invention provides moisture buffering capacity that improves occupant comfort through heat and moisture regulation. Furthermore, due to the combination of its mechanical properties and these heat and moisture regulating properties, the building binder according to the invention is intended to completely or partially replace Portland cement. Indeed, the inventors have demonstrated that, at least at a given concentration, the presence of montmorillonite in the building binder according to the invention allows for very good moisture buffering capacity values ​​that are not achievable under these conditions when using other raw clays such as kaolinite alone.

[0024] Furthermore, as described below, the building binder allows for the achievement of the same mechanical properties as Portland cement (e.g., C12 / 15 grade; C20 / 25 or C25 / 30 grade) while reducing greenhouse gas emissions by 30% to 85% and providing comfort to residents through heat and moisture regulation. Moreover, it contains little or no Portland cement. In fact, as illustrated in the example, the presence of Portland cement results in a reduction in the moisture buffer value.

[0025] Depending on other optional features of the building adhesive, the building adhesive may optionally include one or more of the following features, individually or in combination:

[0026] - The raw clay matrix comprises a mixture of at least two types of clay. Preferably, the raw clay matrix comprises at least one type of raw clay from the montmorillonite group and at least one other clay selected from: illite; kaolinite; vermiculite; chlorite; muscovite; halloysite; sepiolite; or attapulgite. In practice, as shown in the embodiments, the combination of clays allows for better results in terms of moisture buffering capacity and mechanical resistance.

[0027] - The raw clay matrix includes at least one type of clay, said clay having a density of at least 100 m³. 2 The specific surface area per g, for example, as measured according to standard NFP 94-068, is at least equal to 150 m². 2 Specific surface area per g; at least equal to 200 m² 2 Specific surface area per g; or at least equal to 250 m² 2 The specific surface area is / g. More preferably, the raw clay matrix comprises at least two types of clay, wherein the clay has a specific surface area of ​​at least 100m². 2 The specific surface area per g is at least equal to 150 m². 2 Specific surface area per g; at least equal to 200 m² 2 Specific surface area per g; or at least equal to 250 m² 2 The specific surface area is measured using the method described in standard NFP 94-068, NF EN 933-9+A1, or ISO 9277:2010. More preferably, the building adhesive will comprise at least 20% by weight of clay having such a specific surface area, and even more preferably less than 40% by weight.

[0028] It comprises at least 10% by weight of a raw clay matrix, preferably at least 30% by weight, and more preferably at least 40% by weight. In practice, as will be shown in the embodiments, from at least 40% by weight of the raw clay matrix, the building binder allows the preparation of building materials having a moisture buffering capacity (MBV) greater than or equal to 1.3. For example, the raw clay matrix may constitute 40% to 70% by weight of the building binder, preferably 40% to 60% by weight.

[0029] It further comprises a calcined metal oxide composition; preferably, the calcined metal oxide composition is blast furnace slag. In practice, as shown in the examples, the calcined metal oxide composition allows for increased mechanical strength without affecting MBV, unlike Portland cement. Preferably, the building binder comprises at least 20% by weight of the calcined metal oxide composition. More preferably, it has a mass ratio of the raw clay matrix to the calcined metal oxide composition greater than or equal to 1.

[0030] The activating component comprises at least 40% by weight of at least one metal oxide corresponding to an oxide of a metal having at least two valence electrons. Specifically, the activating component may comprise at least 50% by weight of a metal oxide corresponding to an oxide of a metal having at least two valence electrons. The presence of such metal oxides in the activating component at these concentrations allows for an increase in the moisture buffering capacity value.

[0031] The building adhesive comprises at least 10% by weight of at least one metal oxide corresponding to an oxide of a metal having at least two valence electrons. Preferably, the at least 10% by weight may correspond to several different metal oxides. The metal oxides formed from metals having at least two valence electrons may come from several sources. Preferably, these metal oxides will be included in the activated component and / or the calcined metal oxide component. Preferably, the building adhesive comprises at least 15% by weight of at least one metal oxide corresponding to an oxide of a metal having at least two valence electrons, more preferably at least 20% by weight; even more preferably at least 25% by weight, for example at least 30% by weight. The building adhesive may comprise less than 50% by weight of at least one metal oxide corresponding to an oxide of a metal having at least two valence electrons. For example, the building adhesive may comprise between 15% and 40% by weight of at least one metal oxide corresponding to an oxide of a metal having at least two valence electrons.

[0032] - The building binder combined with water and granules has a moisture buffer value of greater than or equal to 0.75, preferably greater than or equal to 1, more preferably greater than or equal to 1.2 and even more preferably greater than or equal to 1.5, measured no earlier than 10 days after manufacturing and preferably 28 days after manufacturing.

[0033] - The antiflocculating agent is an organic compound. Preferably, the antiflocculating agent comprises lignin sulfonate (ester), polyacrylate (ester), humate (ester), or a mixture thereof.

[0034] - It comprises excavated soil including at least a portion of a raw clay matrix. The excavated soil can then be regarded as excavated clay soil.

[0035] It further comprises at least 20% by weight of a calcined aluminosilicate component, or a metal oxide component comprising at least 20% by weight of aluminosilicate.

[0036] According to another aspect, the present invention relates to building materials capable of being formed from building adhesives according to the invention, comprising:

[0037] - At least 2% by weight of at least one type of raw clay from the montmorillonite group,

[0038] - Portland cement less than 3.75% by weight,

[0039] It also has a moisture buffer value of 0.75 or greater, preferably 1 or greater, measured no earlier than 10 days after manufacturing. The moisture buffer value can be measured according to the method for measuring the MBV value described in the instruction manual.

[0040] According to some aspects, the present invention also relates to building materials formed from building adhesives according to the invention, comprising at least 2% by weight of at least one type of raw clay from the montmorillonite family and less than 3.75% by weight of Portland cement.

[0041] Depending on other optional characteristics of the building material, the building material may optionally include one or more of the following characteristics, individually or in combination:

[0042] It comprises at least 2% by weight of calcined metal oxide components.

[0043] - It preferably includes less than 2% Portland cement, more preferably less than 0.1%, and even more preferably does not include Portland cement.

[0044] It includes at least two types of raw clay.

[0045] - It includes at least 5% by weight of at least one metal oxide corresponding to an oxide of a metal having at least two valence electrons.

[0046] - As measured by standard NF EN 206-1, it has a minimum compressive strength on a cylinder of greater than or equal to 2 MPa after 1 day. For example, as measured by standard NF EN 206-1, it may have a minimum compressive strength on a cylinder of greater than or equal to 2 MPa after 28 days. Furthermore, as measured by standard NF EN 206-1, it may have a minimum compressive strength on a cylinder of less than or equal to 20 MPa after 28 days.

[0047] According to another aspect, the present invention relates to prefabricated elements capable of being formed from building adhesives according to the invention, said prefabricated elements:

[0048] -Having a surface area of ​​at least 1m 2 And the thickness of the surface is between 0.3cm and 20cm;

[0049] -Including at least 5% by weight of at least one type of raw clay from the montmorillonite group,

[0050] -Including less than 3.75% by weight Portland cement and

[0051] - Has a moisture buffer value greater than or equal to 0.75, measured no earlier than 10 days after manufacturing. The moisture buffer value can be measured according to the method for measuring MBV values ​​described in the instruction manual.

[0052] According to some aspects, the present invention also relates to prefabricated elements formed from the building adhesive according to the invention, said prefabricated elements having a surface area of ​​at least 1 m². 2 The surface is preferably between 0.3 cm and 20 cm thick; it includes at least 5% by weight of raw clay of at least one montmorillonite family, and less than 3.75% by weight of Portland cement.

[0053] Depending on other optional features of the prefabricated element, the prefabricated element comprises at least 2% by weight of a calcined metal oxide component.

[0054] According to another aspect, the present invention relates to a method for preparing building materials, comprising the following steps:

[0055] - Provides a building binder comprising a raw clay matrix, an antiflocculator, and an activating component, wherein the raw clay matrix comprises at least one raw clay from the montmorillonite group; the at least one raw clay from the montmorillonite group constitutes at least 20% by weight of the building binder; and the building binder comprises less than 15% by weight of Portland cement.

[0056] - Add water and granules, and

[0057] - Mix to obtain building materials.

[0058] According to another aspect, the present invention relates to a method for producing prefabricated components prepared from a building adhesive, said building adhesive comprising a raw clay matrix, an activating component, and an antiflocculating agent, said method comprising:

[0059] - Provides a building binder comprising a raw clay matrix, an antiflocculator, and an activating component, wherein the raw clay matrix comprises at least one raw clay from the montmorillonite family; the at least one raw clay from the montmorillonite family comprises at least 20% by weight of the building binder; and the building binder comprises less than 15% by weight of Portland cement.

[0060] - Mix the building adhesive with granules and water, and

[0061] - A step of curing the mixture, the curing step comprising heat-treating the mixture, preferably at a temperature of 100°C or below, for a duration between 2 and 23 hours.

[0062] In particular, the present invention relates to a method for producing prefabricated components prepared from a building adhesive, the building adhesive comprising a raw clay matrix, an alkaline activating component, and an antiflocculating agent, the method comprising:

[0063] - A building binder is provided, comprising a raw clay matrix, an antiflocculator, and an alkaline activating component, wherein the raw clay matrix comprises at least one raw clay from the montmorillonite group; the building binder comprises 2% to 40% by dry weight of the alkaline activating component; the at least one raw clay from the montmorillonite group comprises at least 20% by weight of the building binder; and the building binder comprises less than 15% by weight of Portland cement.

[0064] - Mix the building adhesive with granules and water, and

[0065] - A step of curing the mixture, the curing step comprising heat-treating the mixture, preferably at a temperature of 100°C or below, for a duration between 2 and 23 hours.

[0066] The mixing of building binders with granules and water allows for the production of building materials. This method enables the creation of building materials with a low carbon footprint and moisture-buffering capacity, which can improve resident comfort through thermal and moisture regulation.

[0067] Furthermore, the use of a curing step allows for rapid curing, which is suitable for the manufacture of prefabricated components.

[0068] Furthermore, in the implementation plan, these precast components, after a curing time of twenty-three hours or less, may have mechanical properties that are at least equal to or even better than those of concrete derived from cement commonly used in the construction industry.

[0069] In addition, certain formulations allow for the production of building materials that can solidify rapidly, which is essential for certain building patterns.

[0070] Therefore, according to another aspect, the present invention relates to building materials formed by or possibly formed by building adhesives according to the present invention.

[0071] Depending on other optional characteristics of the building material, the building material may optionally include one or more of the following characteristics, individually or in combination:

[0072] It will include at least 2% by weight of at least one type of raw clay from the montmorillonite family, for example at least 5% by weight; preferably at least 8% by weight, more preferably at least 10% by weight. In fact, the presence of montmorillonite or similar clay has been shown to improve moisture buffering capacity.

[0073] It will include less than 3.75% Portland cement by weight.

[0074] It will consist of at least two types of raw clay. In fact, it has been shown that the presence of the clay combination allows for improved moisture buffering capacity and mechanical resistance.

[0075] It will also include at least 5% by weight of at least one metal oxide corresponding to an oxide of a metal having at least two valence electrons, preferably at least 10% by weight of at least one metal oxide corresponding to an oxide of a metal having at least two valence electrons. This improves moisture buffering capacity and mechanical strength.

[0076] It contains diatom frustules or plant fibers, preferably hemp scraps.

[0077] - It has a moisture buffer value of 0.75 or greater, preferably 1 or greater, preferably measured no earlier than 10 days after manufacturing.

[0078] -Measured by standard NF EN 206-1, it has a minimum compressive strength in a cylinder of greater than or equal to 2 MPa, preferably greater than or equal to 3 MPa, and preferably greater than 5 MPa in 1 day. Advantageously, measured by standard NF EN 206-1, the building material has a minimum compressive strength in a cylinder of greater than or equal to 8 MPa, preferably greater than or equal to 10 MPa in 7 days.

[0079] Therefore, according to another aspect, the present invention relates to a prefabricated element capable of being formed from the building adhesive according to the invention, and having an area of ​​at least 1m². 2 And the thickness is between 0.3cm and 20cm.

[0080] Such prefabricated elements advantageously have a moisture buffer value measured over 10 days that is greater than or equal to 0.75, preferably greater than or equal to 1, more preferably greater than or equal to 1.2, and even more preferably greater than or equal to 1.5.

[0081] Such prefabricated components advantageously contain less than 3.75% by weight of Portland cement.

[0082] Such prefabricated components advantageously include at least 5% by weight of at least one type of raw clay from the montmorillonite family.

[0083] Such prefabricated components would be particularly well-suited for use in habitations. In fact, a large exchange surface, combined with a high moisture buffer value, would allow for better regulation. Furthermore, the thickness can be selected according to the desired level of regulation.

[0084] Other advantages and features of the present invention will be described in the appendix. Figure 1 It will become apparent from the following description, given the illustrative and non-limiting examples (embodiments), that the appended Figure 1 A diagram illustrating a method for producing prefabricated components prepared from the building adhesive according to the invention. Detailed Implementation

[0085] In the remainder of this specification, the term "% weight" in relation to raw clay matrix, binder, or building material must be understood as a percentage of the dry weight of the binder or building material. Dry weight corresponds to the weight before the addition of, for example, water necessary to form the building material.

[0086] The term "dehydration" within the meaning of this invention corresponds to a formulation comprising a reduced amount of water and a water content of, for example, less than 20% by weight, preferably less than 10%, more preferably less than 5%, more preferably less than 2%, and for example less than 1% by weight. The water content can be measured by any known method of the prior art. It can be measured, for example, according to the standard NF P 94 050 "Determination of the water content by weight of materials: Steaming method" of September 1995.

[0087] The term "clay matrix" refers to one or more layered silicate and / or aluminosilicate rock materials, said clay matrix consisting of fine particles typically derived from three-dimensional framework silicates (e.g., feldspar). Thus, a clay matrix can comprise a mixture of such rock materials, for example, kaolinite, illite, montmorillonite, bentonite, chlorite, vermiculite, metakaolinite, or mixtures thereof. Within the meaning of this invention, "raw clay matrix" corresponds to a clay matrix that has not undergone a calcination step. Specifically, that is, it has not undergone any prior heat treatment. For example, it corresponds to a clay matrix that has not undergone a temperature rise above 300°C, preferably above 200°C, and more preferably above 150°C. In practice, a raw clay matrix may undergo a drying step requiring a temperature rise typically substantially equal to or less than 150°C, but not a calcination step. A raw clay matrix may preferably comprise a mixture of rock materials, such as kaolinite, illite, montmorillonite, bentonite, chlorite, vermiculite, or mixtures thereof.

[0088] Within the meaning of this invention, "deflocculating agent" can refer to a compound that dissociates aggregates and colloids in an aqueous suspension. For example, deflocculating agents have been used in drilling or oil extraction to make clay more fluid and facilitate extraction or drilling.

[0089] Within the meaning of this invention, "activating component" can correspond to a component that has the function of accelerating the formation of a dense structure, thereby increasing the mechanical strength of a material incorporating such an activating component. In particular, "alkaline activating component" includes at least one base, such as a weak or strong base.

[0090] Within the meaning of this invention, the term "metal oxide component" can refer to a component comprising metal oxides such as aluminates. Specifically, the metal oxide component comprises more than 25% by weight of metal oxides, preferably more than 30% by weight, more preferably more than 40% by weight, and even more preferably more than 45% by weight. For example, the metal oxide component comprises more than 2% by weight of aluminates, preferably more than 5% by weight, more preferably more than 7% by weight, and even more preferably more than 10% by weight. Furthermore, the metal oxide may correspond to or include alkaline earth metal oxides. For example, the metal oxide component may include more than 10% by weight of calcium oxide, preferably more than 20% by weight, more preferably more than 25% by weight, and even more preferably more than 30% by dry weight of calcium oxide.

[0091] The metal oxide component may include chemical substances that are not metal oxides. For example, the metal oxide component may include metal-like oxides having, for example, more than 10% by weight, preferably more than 20% by weight, more preferably more than 25% by weight, and even more preferably more than 30% by weight. These mass concentrations can be readily measured by those skilled in the art using conventional techniques for determining metal oxides or metal-like oxides.

[0092] Specifically, the expression "metal oxide composition" refers to a composition comprising more than 50%, preferably more than 70%, more preferably more than 80%, and even more preferably more than 90% of metal oxides and / or metal-like oxides (including aluminates). Preferably, the metal oxide composition corresponds to slag from metallurgy, such as blast furnace slag or fly ash.

[0093] As will be detailed below, the “metal oxide composition” refers to the calcined metal oxide composition. That is, it has undergone a high-temperature step. This high-temperature step can be natural or artificial, in this case, a high-temperature treatment. The high-temperature step may, for example, correspond to treatment at a temperature of 500°C or higher, preferably 750°C or higher, more preferably 900°C or higher, and even more preferably 1000°C or higher.

[0094] Within the meaning of this invention, the term "binder" or "construction binder" can be understood as a formulation that allows materials to agglomerate together, particularly during the setting and hardening of construction materials. Therefore, it particularly allows for the agglomeration of sand and other granular materials with binder components. The binders according to the invention are particularly hydraulic binders, that is, hardening occurs in contact with water.

[0095] The term "Portland cement" refers to a hydraulic binder primarily composed of hydraulic calcium silicate, whose setting and hardening are achieved through a chemical reaction with water. Portland cement typically contains at least 95% clinker and up to 5% minor components such as alkalis (Na₂O, K₂O), magnesium oxide (MgO), gypsum (CaSO₄·2H₂O), or various trace metals.

[0096] The term "building material" as used in this invention generally corresponds to the components comprising the binder, as well as granules and other additives (elements, elements). Specifically, the building material as used in this invention conforms to the standard NF EN 206-1. It may take various forms, such as mortar, concrete, or precast elements, such as concrete blocks. "Rapidly setting building material" may particularly be a building material that, after 24 hours of adding water, has a minimum compressive strength in a cylinder greater than or equal to 2 MPa, preferably greater than or equal to 3 MPa, more preferably greater than or equal to 5 MPa, as measured by standard NF EN 206-1.

[0097] The term "air entrainer" corresponds to an adjuvant intended to be incorporated into the building adhesive according to the invention, and whose primary function is to generate a uniform porosity within the building adhesive once the curing of the adhesive is complete. Such an adjuvant may, for example, correspond to a surfactant, such as an alkyl-ether sulfate (ester).

[0098] The term "moisture buffer value" or "MBV" represents a material's ability to exchange moisture with its environment. It allows for the estimation of the dynamic thermodynamic behavior of the material in question and is used to determine thermal comfort in the construction field, and more specifically, the regulation of internal humidity in rooms or buildings. MBV is expressed in g / m³. 2 %RH represents and indicates the average amount of water exchanged through adsorption or desorption when the surface of a material experiences a change in relative humidity (RH) over a given time period.

[0099] The moisture buffer value can be measured by any method known to those skilled in the art. For example, those skilled in the art may refer to the method described in "Durability and hygroscopic behaviour of biopolymer stabilized earthhen construction materials" Construction and Building Materials 259 (2020). In particular, samples can be placed in a climate chamber at 23°C and 33% relative humidity and left until they have a constant mass (e.g., model climate chamber MHE 612). After equilibration of the samples under these conditions for 15 days, the samples are then exposed to high humidity cycles (75% RH, 8 hours) followed by low relative humidity cycles (33% RH, 16 hours). The samples are weighed periodically using a precise laboratory balance, accurate to 0.01 g. After two stabilization cycles, the samples are removed from the climate chamber.

[0100]

[0101] Where Δm is the change in sample mass caused by the change in relative humidity, S is the total exposed area, and Δ%RH is the difference between humidity levels.

[0102] The term "substantially equal to" in the context of this invention corresponds to a value that changes by less than 20% relative to the comparison value, preferably less than 10%, and even more preferably less than 5%.

[0103] Within the meaning of this invention, the term "prefabricated element" or "precast component" may refer to building components that have undergone a curing process, such as concrete block-type components that can be modularly assembled to manufacture a building. These prefabricated components may include reinforcements (e.g., beams, panels, stairs) or may not include reinforcements (e.g., blocks, interjoists, tiles, slabs).

[0104] The expression "specific surface area" within the meaning of this invention can correspond to the adsorption capacity of clay. It can be measured according to French standard NFP94-068, which indicates a method allowing the determination of the methylene blue value of soil or rock materials via a methylene blue test. Specific surface area can also be measured according to standard NF EN 933-9+A1. In fact, as early as 1950, Dyal and Hendricks (1950) demonstrated a correlation between the adsorption of methylene blue molecules (expressed in g / 100g) via electrostatic interactions and the specific surface area measurement results of clay materials. Furthermore, specific surface area measurements can be performed using the BET (Brunauer, Emmett, and Teller) method. This method is preferably implemented according to the recommendations of standard ISO 9277:2010. Simply put, specific surface area is estimated based on the relationship between the amount of nitrogen adsorbed at the boiling temperature of liquid nitrogen and its pressure under normal atmospheric pressure. Information is interpreted according to the Brunauer, Emmett, and Teller model (BET method).

[0105] In the context of this invention, "excavated clay soil" refers to clay soil obtained after steps such as excavating soil for construction, building, or filling during leveling and / or earthwork operations. For example, excavated clay soil may correspond to quarry fines, dredged sediments, or borehole / flushing mud. Specifically, this refers to soil containing a specific surface area greater than 100 m². 2 / g, preferably greater than 200m 2When the clay content is / g or even montmorillonite group clay; preferably at a content greater than 20% by weight of the clay matrix, they are particularly suitable for the present invention. In particular, within the meaning of the present invention, the excavated clay soil may or may not be moved outside the production site. Preferably, and according to the advantages of the present invention, the excavated soil is used at the production site or at a distance of less than 200 km, preferably less than 50 km. Furthermore, advantageously, the excavated clay soil in the context of the present invention is raw excavated clay soil, that is, it has not undergone a calcination step. In particular, that is, it has not undergone any prior heat treatment. For example, it corresponds to clay soil that has not undergone a temperature rise above 300°C, preferably above 200°C, and more preferably above 150°C. In practice, raw clay soil may undergo a heating step that typically requires a temperature rise of substantially equal to 150°C, but not a calcination step. A calcination step may, for example, correspond to heat treatment at a temperature above 600°C for at least one hour. Conventionally used clay has a relatively constant particle size distribution in which the size is less than 2 μm. The excavated clay soil can have a different particle size distribution. In the context of this invention, the excavated clay soil may include 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 standard ASTM D422-63. Preferably, the excavated clay soil does not contain any particles larger than 2 cm as determined according to standard NF EN 933-1.

[0106] The construction industry must evolve to increase its productivity while addressing new social challenges. In this context, manufacturers have proposed cement blends known as more eco-friendly cement mixes, including, for example, 50% Portland cement, 30% slag, and 20% fly ash; and high-performance concretes incorporating superplasticizers, such as self-compacting concrete, or honeycomb concrete containing gypsum, lime, cement, and sand have also been proposed.

[0107] However, these solutions do not allow for a significant reduction in productivity (i.e., solidification rate and mechanical resistance) with carbon balance and user comfort (especially the control of temperature and humidity levels).

[0108] To overcome this, the inventors have developed a new solution relating to novel building adhesive formulations. The advantage of this new solution is that its carbon footprint is significantly lower than most of the most widely used building adhesives or hydraulic adhesives in the world today (e.g., Portland cement). Furthermore, these solutions ensure optimal regulation of temperature and ambient humidity levels and, in some cases, ensure rapid setting of building materials comprising such adhesive formulations. To this end, the adhesive according to the invention comprises a raw clay matrix that has not undergone a calcination step, an energy-intensive step that also produces greenhouse gases, and more particularly carbon dioxide emissions. The invention particularly relates to a building adhesive comprising a raw clay matrix, an antiflocculator, and an activating component, characterized in that the raw clay matrix contains at least montmorillonite, montmorillonite, or bentonite, preferably more than 10% by weight of a montmorillonite-based clay.

[0109] As will be presented in the embodiments, the method according to the invention allows the manufacture of structural elements from an adhesive comprising a high concentration of raw clay matrix (typically greater than 10%, preferably greater than or equal to 20%), having a mechanical resistance greater than 10 MPa, preferably greater than 12 MPa, at 28 days, and having an MBV greater than 0.7, preferably greater than 1, and more preferably greater than 1.3, and even more preferably greater than 1.5. In particular, the inventors have developed building adhesive compositions that allow the formation of building materials having a minimum compressive strength in a cylinder greater than or equal to 12 MPa, preferably greater than 15 MPa, at 28 days, as measured by standard NF EN 206-1, and a moisture buffer value greater than or equal to 0.7, preferably greater than or equal to 1, more preferably greater than or equal to 1.2, and even more preferably greater than or equal to 1.5.

[0110] The general and preferred characteristics of each component of the building adhesive according to the invention will be presented in detail. These embodiments are applicable not only to the building adhesive according to the invention, but also to other aspects of the invention, such as methods, building materials themselves (including prefabricated elements), or the use of building adhesives and building materials.

[0111] raw clay matrix

[0112] The raw clay matrix may include, for example, at least one mineral selected from the following: illite, kaolinite, montmorillonite, bentonite, vermiculite, chlorite, muscovite, halloysite, sepiolite, and attapulgite.

[0113] Specifically, the raw clay matrix contains montmorillonite, preferably montmorillonite. Specifically, the clay matrix comprises at least 10% by weight of montmorillonite, preferably montmorillonite, more preferably at least 20% by weight.

[0114] In fact, the inventors have shown that if the raw clay matrix comprises at least one raw clay from the montmorillonite family, and particularly when the at least one raw clay from the montmorillonite family accounts for more than 10% by weight of the building binder, preferably at least 20% by weight of the building binder, then the building binder allows for the preparation of building materials that combine mechanical properties and moisture buffering capacity.

[0115] The smectite family includes montmorillonites and bentonite.

[0116] Preferably, the raw clay matrix comprises at least two types of clay selected from: illite; montmorillonite (preferably montmorillonite); kaolinite; bentonite; vermiculite; chlorite; muscovite; halloysite; sepiolite; or attapulgite. This includes clay known as interstratified clay, which is a composite combination of several clays. Even more preferably, the raw clay matrix contains at least one mineral material selected from kaolinite, illite, montmorillonite, bentonite, chlorite, and vermiculite.

[0117] Table 1 below lists the chemical properties of these minerals.

[0118] [Table 1]

[0119]

[0120]

[0121] As already explained, according to a preferred embodiment, the building adhesive according to the invention will comprise at least two different types of clay and will include montmorillonite.

[0122] The type of clay can be determined by methods known to those skilled in the art. In particular, X-ray diffraction will be possible. For example, the following conditions can be used:

[0123] - Equipment: Diffractometer, such as BRUKER D8 ADVANCE (Bragg-Brentano Geometry); for example, with the following setup: copper tube Generator power: 40kV, 40mA; Primary optics: Fixed slit 0.16°; Soller slit 2.5°; Secondary optics: Soller slit 2.5°; LynXeye XE-T detector

[0124] - Acquisition parameters: 4-90° 2θ scan; scan speed 0.03° 2θ / sec; counting time: 480 sec / step; sample rotation.

[0125] For example, the building adhesive according to the invention comprises at least 10% by weight of a raw clay matrix, preferably at least 20% by weight of a raw clay matrix, more preferably at least 30% by weight of a raw clay matrix, and even more preferably at least 40% by weight of a raw clay matrix. For example, at least 50% by weight of a raw clay matrix or at least 60% by weight of a raw clay matrix.

[0126] Furthermore, preferably, the building adhesive according to the invention comprises up to 80% by weight of a raw clay matrix, more preferably up to 70% by weight of a raw clay matrix.

[0127] Therefore, in particular, the building adhesive according to the invention may contain 20 to 80% by weight of raw clay matrix, preferably 30 to 80% by weight or 40 to 80% by weight of raw clay matrix, more preferably 40 to 70% by weight of raw clay matrix.

[0128] Preferably, the raw clay matrix of the building adhesive according to the invention contains at least 20% by weight of montmorillonite, for example at least 30% by weight of montmorillonite, preferably at least 40% by weight of montmorillonite, more preferably at least 50% by weight of montmorillonite, and even more preferably at least 60% by weight of montmorillonite.

[0129] In particular, the clay matrix according to the invention may contain 20 to 80% by weight of montmorillonite, preferably 30 to 70% by weight or 40 to 60% by weight of montmorillonite, more preferably 40 to 60% by weight of montmorillonite.

[0130] Preferably, montmorillonite can be montmorillonite clay.

[0131] More preferably, the raw clay matrix of the building adhesive according to the invention comprises at least one raw clay selected from the montmorillonite family and at least one other raw clay selected from kaolinite, illite, chlorite, and vermiculite. Even more preferably, the raw clay matrix of the building adhesive according to the invention comprises montmorillonite and at least one other raw clay selected from kaolinite, illite, bentonite, montmorillonite, chlorite, and vermiculite.

[0132] Even more preferably, the building binder comprises excavated soil, which includes a raw clay matrix. It may include at least 2% by weight of silt particles, preferably at least 4% by weight, more preferably at least 6% by weight. The silt particles are particularly those with a diameter between 2 μm and 125 μm, preferably between 2 μm and 50 μm.

[0133] The excavated clay soil may advantageously have been pretreated, the pretreatment being selected from: grinding, sorting, sieving, and / or drying of the excavated clay soil. Pretreatment may include, for example, grading.

[0134] The advantage of the building adhesive according to the invention is that it can include a large amount of raw clay matrix without altering the hygroscopic or mechanical properties of the building material, thereby allowing the production of building materials that additionally possess moisture buffering capacity and, in some cases, have improved setting time compared to conventionally used building materials.

[0135] Anti-flocculation agent

[0136] Many compounds can act as antiflocculators, and many are generally known to those skilled in the art.

[0137] In the context of this invention, the antiflocculating agent is particularly a nonionic surfactant, such as a polyoxyethylene ether. The polyoxyethylene ether may be selected, for example, from poly(oxyethylene) lauryl ether.

[0138] Antiflocculators can also be anionic reagents, such as anionic surfactants. In particular, the anionic reagent may be selected from: alkyl aryl sulfonates (esters), amino alcohols, fatty acids, humates (esters) (e.g., sodium humate), carboxylic acids, lignin sulfonates (esters) (e.g., sodium lignin sulfonate), polyacrylates (esters), carboxymethyl cellulose, and mixtures thereof.

[0139] Antiflocculation agents can also be polyacrylates (esters). These can then be selected from, for example, sodium polyacrylate and ammonium polyacrylate.

[0140] The antiflocculating agent may also be an amine, selected from, for example: 2-amino-2-methyl-1-propanol; mono-, di-, or triethanolamine; isopropanolamines (1-amino-2-propanol, diisopropanolamine, and triisopropanolamine) and N-alkylated ethanolamines.

[0141] Alternatively, the antiflocculator may be a mixture of compounds, such as a mixture of at least two compounds selected from nonionic surfactants, anionic reagents, polyacrylates, amines, and organophosphorus compounds.

[0142] The antiflocculating agent may be an organic antiflocculating agent. According to the present invention, the organic antiflocculating agent comprises at least one carbon atom, and preferably at least one carbon-oxygen bond. Preferably, the antiflocculating agent is selected from: lignin sulfonates (esters) (e.g., sodium lignin sulfonate), polyacrylates (esters), humates (esters), polycarboxylates (esters) such as ether polycarboxylates (esters), and mixtures thereof. More preferably, the antiflocculating agent comprises humates (esters), lignin sulfonates (esters), and / or polyacrylates (esters).

[0143] Antiflocculation agents are preferably in powder form (such as salt).

[0144] However, the present invention is not limited to the antiflocculating agents mentioned above. Any type of antiflocculating agent known to those skilled in the art can be used instead of the antiflocculating agents mentioned above.

[0145] Specifically, the antiflocculating agent comprises at least 0.5% by weight of the raw clay matrix, preferably at least 1% by weight, more preferably at least 2% by weight, even more preferably at least 3% by weight, and for example at least 4% by weight. Furthermore, the antiflocculating agent may comprise up to 5% by weight of the raw clay matrix.

[0146] Specifically, the antiflocculating agent comprises at least 0.1% by weight of the building adhesive, preferably at least 0.5% by weight. Furthermore, the antiflocculating agent may comprise up to 5% by weight of the building adhesive, preferably up to 4% by weight, more preferably up to 3% by weight, and even more preferably up to 2% by weight.

[0147] In practice, at such concentrations of antiflocculating agent, the building binder according to the invention can then be used in combination with the activating component to form a material with favorable hydrothermal and mechanical properties. Furthermore, to avoid degradation of the mechanical properties of the building material, it is recommended not to exceed a certain antiflocculating agent ratio. Excessively high concentrations of antiflocculating agent combined with the raw clay matrix and the activating component may reduce mechanical properties and / or MBV performance.

[0148] Activated components

[0149] The activating component is preferably an alkaline activating component.

[0150] The alkaline activating component includes at least one base, such as a weak or strong base. The activating component preferably includes one or more compounds with 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.

[0151] Therefore, the alkaline activating component may include sulfates (esters), hydroxides, carbonates (esters), lactates (esters), organophosphates (esters), or combinations thereof.

[0152] Preferably, the alkaline activating component includes hydroxides.

[0153] In particular, the alkaline activating component may include a mixture of sodium sulfate / calcium sulfate and sodium chloride / calcium chloride.

[0154] Preferably, the alkaline activating component comprises a carbonate (ester). In particular, the alkaline activating component may comprise a mixture of sodium silicate or potassium silicate and sodium carbonate or potassium carbonate. The activating component may also comprise an alkaline compound, preferably a strong base.

[0155] Advantageously, the activating component comprises an oxide of a metal having at least two valence electrons. In fact, in such a configuration, the moisture buffering value is improved compared to basic activating components based on sulfates (esters), hydroxides, carbonates (esters), lactates (esters), organophosphates (esters), or combinations thereof. Specifically, the activating component may comprise at least 40% by weight of at least one metal oxide corresponding to an oxide of a metal having at least two valence electrons. For example, at least 40% by weight may correspond to several different metal oxides. However, preferably, the activating component, especially when the latter is a basic activating component, may comprise a single oxide of a metal having at least two valence electrons or more than 50% by weight of such an oxide.

[0156] Preferably, the activating component comprises at least 50% by weight of at least one metal oxide corresponding to an oxide of a metal or alkaline earth metal having at least two valence electrons, more preferably at least 60% by weight; and even more preferably at least 80% by weight.

[0157] The presence of metal oxides (e.g., having at least two valence electrons) can be identified by X-ray fluorescence spectroscopy (XRF) and / or X-ray diffraction (XRD).

[0158] The alkaline activating component may include an organophosphorus compound, such as sodium tripolyphosphate. Preferably, the organophosphorus compound constitutes at least 2% by weight of the building adhesive.

[0159] Preferably, the alkaline activating component includes lactate (ester), such as sodium lactate, potassium lactate and / or lithium lactate.

[0160] As described below, the activating component may be a liquid component. In particular, the activating component may be an aqueous component. As will be described later, its use during the formation of the building adhesive according to the invention may be combined with the addition of water. However, alternatively, the activating component is in solid form, such as in powder form. The percentage of alkaline activating component shown corresponds to the dry weight of said component.

[0161] The activating component is present, for example, at a content of at least 2% dry weight of the building adhesive.

[0162] Preferably, the building adhesive contains 2% to 50% by dry weight of an alkaline activating component. More preferably, the building adhesive contains 2% to 40% by dry weight of an alkaline activating component. Even more preferably, the building adhesive contains 10% to 20% by dry weight of an alkaline activating component.

[0163] As will be illustrated in the examples, the required concentration of the alkaline activating component can vary widely depending on its composition. Therefore, the building adhesive according to the invention may contain 20% to 40% by weight of the alkaline activating component. This is especially true when the alkaline activating component includes hydroxides. Alternatively, the building adhesive according to the invention may contain 2% to 10% by weight of the alkaline activating component. This is especially true when the alkaline activating component includes carbonates (esters). Finally, the building adhesive according to the invention may contain 10% to 30% by weight of the alkaline activating component, preferably 15% to 25% by weight.

[0164] The presence of the active component can be identified by spectroscopic methods, depending on the active component used. For example, the composition of a building material can be identified by infrared spectroscopy.

[0165] Calcinated metal oxide components

[0166] As will be shown in the embodiments, the building adhesive according to the invention preferably comprises less than 15% by weight of Portland cement, more preferably less than 10% by weight, less than 8% by weight, less than 5% by weight, less than 3% by weight, less than 2% by weight, and even more preferably does not include Portland cement.

[0167] In fact, the presence of Portland cement leads to a decrease in the moisture buffering capacity.

[0168] The metal oxide component advantageously includes metal oxides selected from: iron oxides such as FeO, Fe3O4, Fe2O3, aluminum oxide Al2O3, manganese(II) oxide MnO, titanium(IV) oxide TiO2, magnesium oxide MgO, and mixtures thereof. It may also include metal oxides selected from: calcium oxide and magnesium oxide.

[0169] The components of metal oxides may also include aluminosilicates.

[0170] The components of the metal oxide are selected from, for example:

[0171] -Blast furnace slag,

[0172] - Volcanic ash, such as volcanic ash, fly ash, silica fume, or metakaolin.

[0173] Ash from plant materials, such as rice ash.

[0174] - Bauxite residue, or

[0175] - Their combination.

[0176] Preferably, the metal oxide in the calcined metal oxide component is a transition metal oxide. The metal oxide may preferably be derived from a component of blast furnace slag, for example, formed during the production of cast iron from iron ore.

[0177] The inventors have determined the importance of the mass fraction of the metal oxide in combination with the raw clay matrix. Preferably, the building binder comprises at least 10% by weight of the metal oxide.

[0178] For example, the building binder according to the invention may include at least 15% by weight of blast furnace slag components.

[0179] Advantageously, the building binder comprises, for example, 10% by weight of aluminosilicate, preferably at least 10% by weight, more preferably at least 20% by weight, obtained by a calcination method.

[0180] For example, a building adhesive may include at least 20% by weight of a component of calcined aluminosilicate, or a component of calcined metal oxide may include at least 20% by weight of aluminosilicate in the building adhesive.

[0181] Aluminosilicates are derived from sources such as alumina, red mud, fly ash, blast furnace slag, or metakaolin.

[0182] Unrestricted by theory, the balance between the amount of calcined metal oxide components and the raw clay matrix, combined with the alkaline activating components, enhances the bonding between clay flakes, thereby improving its mechanical properties to the binder, while maintaining optimal hydrothermal properties due to the antiflocculating agent and the type of clay selected. This is especially true when the clay matrix includes montmorillonite, which the inventors have found particularly suitable for the preparation of building materials with high MBV values ​​(e.g., >0.7, or preferably >1) when combined with antiflocculating agents and activating components.

[0183] Furthermore, the inventors have determined that certain values ​​of the ratio between the mass of the metal oxide component and the mass of the raw clay matrix allow for a sufficient balance between mechanical resistance, moisture capacity, and setting rate.

[0184] Advantageously, the metal oxide component and the raw clay matrix are present in the building adhesive such that the mass ratio of the raw clay matrix to the metal oxide component is less than or equal to 6, preferably less than or equal to 4, and more preferably less than or equal to 2.

[0185] For example, the metal oxide component and the raw clay matrix are present in the building adhesive such that the mass ratio of the raw clay matrix to the metal oxide component is preferably greater than or equal to 0.3; more preferably greater than or equal to 0.5, and even more preferably greater than or equal to 1.

[0186] For example, the metal oxide component and the raw clay matrix are present in the building adhesive such that the mass ratio of the raw clay matrix to the metal oxide component is 0.3 to 3, more preferably 1 to 3, and even more preferably 1 to 2.

[0187] Advantageously, the metal oxide component and the antiflocculating agent are present in the building adhesive such that the mass ratio of the metal oxide component to the antiflocculating agent is greater than or equal to 12, preferably greater than or equal to 15.

[0188] Specifically, the metal oxide component, also known as the calcined metal oxide component, accounts for 20% to 70% by weight of the building adhesive.

[0189] Preferably, the metal oxide component, also known as the calcined metal oxide component, accounts for 35% to 65% by weight of the building adhesive.

[0190] More preferably, the metal oxide component, also known as the calcined metal oxide component, accounts for 40% to 65% by weight of the building adhesive.

[0191] The presence of calcined metal oxide components can be identified by spectroscopic methods, depending on the calcined metal oxide components used. For example, the composition of calcined metal oxide components in building materials may be identified by scanning electron microscopy, scanning electron microscopy coupled to a microprobe, or by X-ray fluorescence spectroscopy (XRF) and / or by X-ray diffraction (XRD).

[0192] The building adhesive may include many other compounds. For example, it may contain adjuvants, preferably at least 1% by weight of the adhesive. In particular, the adjuvant is an air-entraining agent. Those known to those skilled in the art can use, for example, those known in conventional concrete.

[0193] As detailed above, the inventors have never proposed combining blast furnace slag, fly ash, etc., with raw clay and an activating component (preferably alkaline) to produce building materials with good water buffer capacity (MBV) (i.e., greater than or equal to 0.7) and rapid setting. Specifically, it has never been proposed to combine blast furnace slag, fly ash, etc., with a clay matrix comprising at least one raw clay from the montmorillonite group, said at least one raw clay from the montmorillonite group comprising at least 20% by weight of the building binder, said activating component preferably alkaline, to produce building materials with good water buffer capacity (MBV) and rapid setting. These building binder compositions further comprise less than 15% by weight of Portland cement.

[0194] Furthermore, among all formulations, compositions (components) or adhesives according to the invention that can be effectively used in the methods according to the invention, the inventors have identified certain formulations (formulations) of building adhesives that are novel in themselves and possess reduced carbon balance, rapid setting, hygrothermal properties, and high mechanical properties. These new and particularly effective formulations themselves constitute part of the subject matter of this invention.

[0195] This invention also relates to a building adhesive comprising a raw clay matrix, an antiflocculating agent, and an activating component, wherein the building adhesive comprises:

[0196] - At least 40% by weight of a raw clay matrix, said raw clay matrix comprising at least one type of raw clay from the montmorillonite family; and said at least one type of raw clay from the montmorillonite family constitutes at least 20% by weight of the building adhesive; and

[0197] - Portland cement less than 15% by weight.

[0198] This invention also relates to a building adhesive comprising a raw clay matrix, an antiflocculating agent, and an activating component, wherein the building adhesive comprises:

[0199] - At least 40% by weight of raw clay matrix, said raw clay matrix comprising at least one type of raw clay from the montmorillonite family; and said at least one type of raw clay from the montmorillonite family comprises at least 20% by weight of the building adhesive;

[0200] - At least 35% by weight of blast furnace slag; and

[0201] - Portland cement less than 15% by weight.

[0202] This invention also relates to a building adhesive comprising a raw clay matrix, an antiflocculating agent, and an activating component, wherein the building adhesive comprises:

[0203] - At least 40% by weight of raw clay matrix, said raw clay matrix comprising at least one type of raw clay from the montmorillonite family; and said at least one type of raw clay from the montmorillonite family comprises at least 20% by weight of the building adhesive;

[0204] - Portland cement less than 15% by weight; and

[0205] - At least 0.5% by weight of an antiflocculating agent, said antiflocculating agent comprising an organic compound selected from humates (esters), lignin sulfonates (esters), and polyacrylates (esters).

[0206] This invention also relates to a building adhesive comprising a raw clay matrix, an antiflocculating agent, and an activating component, wherein the building adhesive comprises:

[0207] - At least 40% by weight of raw clay matrix, said raw clay matrix comprising at least one type of raw clay from the montmorillonite family; and said at least one type of raw clay from the montmorillonite family comprises at least 20% by weight of the building adhesive;

[0208] - Portland cement less than 15% by weight; and

[0209] - At least 15% by weight of an activator, said activator comprising at least 70% by weight of at least one metal oxide corresponding to an oxide of a metal having at least two valence electrons.

[0210] According to another aspect, the present invention relates to the use of a combination of raw clay matrix and antiflocculating agent and activating component for the preparation of a building adhesive, wherein the raw clay matrix comprises at least two types with a specific surface area of ​​at least 100 m². 2 A mixture of clays at a concentration of / g. Specifically, the raw clay matrix comprises at least one type of clay having a density of at least 100m³. 2 The specific surface area per g is at least equal to 150 m². 2 Specific surface area per g; at least equal to 200 m² 2 Specific surface area per g; or at least equal to 250 m² 2 The specific surface area is 1 / g. Preferably, the raw clay matrix comprises at least two types of clay, wherein the clay has a specific surface area of ​​at least 100 m² / g. 2 The specific surface area per g is at least equal to 150 m². 2 Specific surface area per g; at least equal to 200 m² 2 Specific surface area per g; or at least equal to 250 m² 2 Specific surface area per g.

[0211] The present invention also relates to the use of a raw clay matrix comprising at least one raw clay from the montmorillonite family, combined with an antiflocculator and an activating component, for the preparation of a building adhesive, wherein the at least one raw clay from the montmorillonite family comprises at least 20% by weight of the building adhesive; and the building adhesive comprises less than 15% by weight of Portland cement.

[0212] The building adhesive according to the invention can be used to produce cladding elements, particularly floor cladding such as tiles, boards, pebbles or curbs, wall cladding such as interior or exterior facade elements, brick slips, paneling elements, or tile-type roof cladding, for producing extruded or molded building modules such as bricks, or for producing various extruded shapes.

[0213] The building adhesive according to the invention can be used to produce composite materials, such as prefabricated panel type building panels, prefabricated blocks, such as doors or curtains, prefabricated wall elements, or any other prefabricated building elements.

[0214] The building adhesive according to the invention can be used to produce insulating modules, such as partitions, or lightweight insulating building modules (density less than 1.5 kg / L, preferably less than 1.2 kg / L, more preferably less than 1.0 kg / L, and even more preferably less than 0.7 kg / L).

[0215] The present invention also relates to the use of the building adhesive according to the invention for implementing additive manufacturing. In particular, additive manufacturing can be performed by means of an automated 3D construction system such as a 3D printer. Such additive manufacturing can allow the manufacture of building components, buildings or houses, or even decorative objects.

[0216] The building adhesive according to the invention can be used in the form of a two-component system, which has a component in solid form on one hand and a component in liquid form on the other hand, or has components in the form of two pastes, for use in the production of mastic, glue or sealing mortar.

[0217] According to another aspect, the present invention relates to a method for preparing a building adhesive. Such a method according to the invention particularly relates to the production of a building adhesive that allows for the production of building materials with high moisture buffering capacity (i.e., greater than 0.75).

[0218] As previously stated, the raw clay matrix may include at least one mineral material selected from: illite; montmorillonite (preferably montmorillonite); kaolinite; bentonite; vermiculite; chlorite; muscovite; halloysite; sepiolite; or attapulgite. This includes clay known as interlayer clay, which is a composite combination of several clays.

[0219] This method specifically includes mixing a raw clay matrix, an antiflocculating agent, and an activating component. The raw clay matrix comprises at least one type of raw clay from the montmorillonite family, and the at least one type of raw clay from the montmorillonite family constitutes at least 20% by weight of the building binder. Furthermore, the building binder preferably contains less than 15% by weight of Portland cement.

[0220] The method may include a homogenization or mixing step to obtain a building adhesive. This homogenization or mixing step may particularly last for at least 45 seconds, preferably at least 60 seconds, more preferably at least 90 seconds; and for example, less than 30 minutes; preferably less than 10 minutes; more preferably less than 5 minutes.

[0221] Following the mixing step, the method according to the invention may include adding additives or materials that allow alteration of the mechanical properties of the final building material.

[0222] The added material may be, for example, granules, whether recycled or not, selected from fillers, powders, sand, crushed stone, gravel and / or fibers, and optionally pigments. Typically, granules may correspond to sand or sand and other aggregates such as crushed stone, gravel, pebbles, hemp chips and / or other plant aggregates.

[0223] The method may also include the addition of plasticizers or superplasticizers.

[0224] The method may also include the addition of fibers. Fibers may be selected from, for example, plant fibers such as flax, hemp, cellulose, bamboo, and awn fibers; synthetic fibers such as metal, glass, carbon, and polypropylene fibers; and mixtures thereof. The presence of fibers allows for the formation of building materials with improved mechanical and insulating properties.

[0225] The method may also include adding aggregates. Aggregates may be selected from, for example, gravel, crushed, recycled concrete, and mixtures thereof.

[0226] The method may also include the addition of additives. Additives may be selected from, for example, synthetic or natural rheology control agents, anti-shrinkage agents, water-retaining agents, air-entraining agents, synthetic resins, and mixtures thereof.

[0227] The preparation of the building adhesive according to the invention will specifically include the addition of sand and water. The sand may be derived from rock cuttings, particularly in the case of "on-site" concrete. The sand may also be desert sand.

[0228] For example, the building materials obtained can be selected from: mortar, paint or plasters.

[0229] In some implementations, the building adhesive will be used to prepare prefabricated components.

[0230] Therefore, according to another aspect, the present invention relates to a method for producing prefabricated components. In this case, it is important that, in addition to moisture buffering capacity, the building adhesive also allows for rapid setting of the building materials.

[0231] Precast components are specifically prepared from building binders containing raw clay matrix, antiflocculation agents, and activating components, with added granules and water.

[0232] Specifically, in the building adhesive used in this method, the raw clay matrix comprises at least one raw clay from the montmorillonite family; the at least one raw clay from the montmorillonite family accounts for at least 20% by weight of the building adhesive; and the building adhesive contains less than 15% by weight of Portland cement. As described above, this method benefits from embodiments of the building adhesive, and therefore, more preferably, the building adhesive contains less than 10% by weight of Portland cement, less than 8% by weight, less than 5% by weight, less than 3% by weight, less than 2% by weight, and even more preferably, does not contain Portland cement.

[0233] like Figure 1 As shown, the method 100 according to the present invention includes the following steps: step 110 of supplying a building adhesive, step 120 of mixing the components of the adhesive for building materials with granules and water, and step 130 of curing the mixture.

[0234] As shown in the figure, the method according to the present invention may further include the steps of preparing mold 101, demolding preform 140 and drying preform 150.

[0235] However, as will be illustrated in the embodiments, the inventors have determined the selection and application conditions of the clay to allow for the acquisition of building materials that permit high levels of mechanical resistance and rapid setting, despite the high level of raw clay. In particular, under the selected conditions, the clay matrix may be present in the building material at a weight greater than 10% of the binder, preferably at a weight greater than 20% of the binder.

[0236] Therefore, it is possible to obtain materials with a moisture buffering capacity of 0.75 or higher and a low carbon balance, while respecting the productivity requirements of the construction industry.

[0237] Specifically, as will be illustrated in the embodiments, the raw clay matrix comprises at least one raw clay from the montmorillonite family. Optimal results are obtained in terms of moisture buffering capacity when the raw clay matrix comprises one or more of these clays.

[0238] In addition to the selection of the clay to be used, the inventors have determined that in order to obtain building materials with high moisture buffering capacity and rapid solidification, it is necessary to add an anti-flocculating agent and perform heat treatment.

[0239] Therefore, advantageously, in the context of the method 100 for producing prefabricated components according to the invention, the curing step 130 includes heat treatment of the mixture. In fact, the combination of heat treatment and the presence of montmorillonite-based clay allows for the production of building materials with a moisture buffering capacity greater than or equal to 0.75 while exhibiting rapid setting.

[0240] like Figure 1 As described and shown, the method 100 for producing prefabricated elements according to the invention may include steps for preparing a mold 101, wherein, for example, a release agent and a template oil are used, a gasket for reinforcement is used, or a system that allows for airtight coverage of the component or cured product is used.

[0241] Furthermore, the method according to the invention may include a first step of preparing a building adhesive mixture. The step of preparing the building adhesive mixture may, for example, include dry mixing. In fact, most or all of the components of the building adhesive can be used in dehydrated form.

[0242] Alternatively, some of the ingredients can be dry-mixed, while others are added in liquid form.

[0243] In particular, the method according to the invention includes step 120 of mixing the components of the building adhesive with granules and water.

[0244] The water-to-dry matter mass ratio of the composition (referred to herein as the building binder) is preferably controlled. The water / dry matter mass ratio is preferably less than 1, more preferably less than or equal to 0.6, and even more preferably less than or equal to 0.5. This ratio does not take into account the amount of added aggregate.

[0245] Traditionally, pellets can refer to natural pellets, artificial pellets, or recycled pellets. Pellets can further include mineral pellets, meaning pellets primarily composed of mineral materials, and / or plant pellets, meaning pellets primarily composed of plant-derived materials. Pellets can further include marine pellets, meaning pellets primarily composed of organic or inorganic materials derived from the seabed, such as siliceous pellets and limestone materials (e.g., maerl and shell sand). For example, mineral pellets can correspond to sand, gravel, pebbles, fillers (or fine materials), powders, fossil waste, and combinations thereof.

[0246] For example, plant pellets can correspond to wood (fragments or fibers), hemp, straw, hemp chips, miscanthus, sunflower, cattail, corn, flax, rice husk, wheat bales, rapeseed, seaweed, bamboo, cellulose filler, rags and combinations thereof.

[0247] In particular, when the building materials or prefabricated components according to the invention include plant-based aggregates, they preferably comprise at least 10% by weight, more preferably at least 15% by weight, more preferably at least 20% by weight, and even more preferably at least 25% by weight. Generally, when using plant-based aggregates, the building materials or prefabricated components according to the invention will preferably comprise up to 60% by weight, and more preferably up to 50% by weight. For example, the building materials or prefabricated components according to the invention may preferably comprise between 10% and 50% by weight of plant-based aggregates, and more preferably between 15% and 35% by weight. When plant-based aggregates are used in compressed concrete blocks according to the invention, they can be combined with mineral aggregates (e.g., sand). This improves mechanical properties.

[0248] Such mixing steps can be advantageously, but not exhaustively, carried out in apparatus selected from: mixers and truck mixers (concrete mixer trucks) or more generally in any apparatus suitable for mixing building binders. Dispersion devices employing, for example, ultrasonication can be used.

[0249] Furthermore, the mixing step 120 can be carried out over a duration of up to 24 hours, preferably up to 12 hours, and more preferably up to 6 hours. Advantageously, in the context of method 100 for manufacturing preformed components, it can be as short as tens of minutes, and thus less than an hour or even tens of seconds. In practice, the mixture can be produced on a press, with or without vibration, wherein the mixture is produced a few seconds before the mold is filled.

[0250] Prior to the optional curing step 130, or during or before the mixing step 120, the method 100 according to the invention may include the addition of additives or materials that allow for alteration of the mechanical properties of the final building material.

[0251] Therefore, the method may also include the addition of plasticizers or superplasticizers.

[0252] Method 100 may also include the addition of fibers. Fibers may be selected, for example, from plant fibers such as flax, hemp, cellulose, bamboo, and awn fibers; and synthetic fibers such as metals, glass, carbon, polypropylene, and mixtures thereof. The presence of fibers advantageously allows for the formation of building materials with improved mechanical and insulating properties while retaining moisture-buffering capacity.

[0253] Method 100 may also include adding aggregate. Aggregate may be selected from, for example, gravel, crushed, recycled concrete and mixtures thereof.

[0254] Method 100 may also include the addition of additives. Additives may be selected from, for example, synthetic or natural rheology control agents, anti-shrinkage agents, water-retaining agents, air-entraining agents, synthetic resins, and mixtures thereof.

[0255] The method 100 according to the invention may further include the step of curing the mixture 130.

[0256] The curing step 130 is generally known to those skilled in the art as to the ability to perform the curing step 130. For example, it can be achieved by holding the product in a curing chamber, by covering it, or by spraying water or curing the product.

[0257] The curing step 130 preferably lasts for up to 48 hours, more preferably up to 24 hours, more preferably less than 23 hours, and it may be substantially equal to 20 hours. The curing step 130 generally lasts for at least 2 hours, preferably at least 6 hours, and more preferably at least 12 hours.

[0258] Preferably, in the context of this invention, the curing step 130 is performed in an airtight mold. An airtight mold advantageously allows for the restriction or elimination of exchange between the mixture and outside air.

[0259] The curing process may or may not include heat treatment. However, even when heat treatment is performed, it is done at temperatures below 500°C, so the clay is always raw after curing and there is no removal of bound water. In other words, the clay is not calcined and can still be considered raw clay. In contrast to what was observed during the use of metakaolin (Konan et al., *Etude comparative de la déshydroxylation / amorphisation dans deuxkaolins de cristallinitédifférente. J. Soc. Ouest-Afr. Chim. (2010) 030; 29-39)), the effectiveness of the pozzolanic reaction on the mechanical properties of concrete is here independent of the total dehydroxylation and amorphization of the clay. Furthermore, the reaction with the activating component does not alter the structure of the raw clay, which is always identifiable in the final material, for example, by scanning electron microscopy.

[0260] In the context of this invention, heat treatment is preferably performed at a temperature above 25°C, more preferably above 30°C. However, to respect a favorable energy balance, the curing step is performed at a temperature below 120°C, preferably below 100°C, and more preferably below or equal to 80°C. For example, the heat curing step is performed at a temperature between 20°C and 90°C, preferably between 25°C and 80°C; even more preferably between 25°C and 65°C.

[0261] Furthermore, heat treatment can be performed throughout the curing process, but it can also be performed within a shorter time. Therefore, preferably, heat treatment is performed within a time period of less than or equal to 20 hours, more preferably less than 15 hours, and even more preferably less than 10 hours.

[0262] like Figure 1 As shown, the method according to the invention may include step 140 of demolding a prefabricated component. Demolding step 140 is generally known to those skilled in the art who will know how to implement it. This step is facilitated, in particular, by any mold-making step, by, for example, the use of a release agent and mold oil, the use of gaskets for reinforcement, or the use of a system that allows for airtight coverage of the component.

[0263] Finally, the method according to the invention may include the step of drying the prefabricated element 150. The drying step 150 is generally known to those skilled in the art who will know how to perform it. This step can be carried out under special conditions, particularly under protection from wind, frost, and sun.

[0264] In the context of various embodiments and features of the present invention, the inventors are able for the first time to obtain prefabricated components or building materials having a moisture buffer value greater than or equal to 0.75, preferably greater than or equal to 0.1, and more preferably greater than or equal to 1.2.

[0265] Furthermore, certain prefabricated components or building materials are rapidly curing, possessing a minimum compressive strength on a cylinder of 16 MPa or greater, preferably 18 MPa or greater, more preferably 20 MPa or greater, as measured by standard NF EN 206-1, after 20 hours or less of the curing step. Therefore, building adhesives, particularly rapid-curing building adhesives, and similarly, the building materials according to the invention are rapid-curing building materials.

[0266] The method according to the invention can be incorporated into the embodiments of the above-described building adhesives, whether they are advantageous, particular or preferred, especially regarding the characteristics of the main components of the building adhesive: the raw clay matrix, the antiflocculating agent, the activating component and the calcined metal oxide component.

[0267] According to another aspect, the present invention relates to building materials comprising building adhesives according to the invention. In particular, the present invention relates to building materials formed from building adhesives according to the invention. For example, the building materials may be selected from: mortar, paint, plaster, insulators, lightweight concrete, and precast components.

[0268] This invention relates to building materials obtained or potentially obtained from the method according to the invention.

[0269] Advantageously, the building adhesive according to the invention is used to form building materials such that the filler accounts for 200% to 900% of the building adhesive by weight. For example, in the building materials according to the invention, the building adhesive according to the invention preferably accounts for 10% to 33% of the building materials by weight.

[0270] In particular, the building material formed by the building adhesive according to the invention will include at least 5% by weight of raw clay from the montmorillonite group. Preferably, the building material will include at least 8% by weight of raw clay from the montmorillonite group, and even more preferably at least 10% by weight of raw clay from the montmorillonite group.

[0271] Advantageously, the building material formed from the building adhesive according to the invention will also include at least 5% by weight of at least one metal oxide corresponding to an oxide of a metal having at least two valence electrons. Preferably, the at least 5% by weight may be formed from several different metal oxides. These metal oxides may come from several sources. Preferably, the metal oxide formed from a metal having at least two valence electrons will be included in the activating component and / or the calcined metal oxide component. Preferably, the building material includes at least 10% by weight of at least one metal oxide corresponding to an oxide of a metal having at least two valence electrons, more preferably at least 15% by weight; even more preferably at least 20% by weight.

[0272] The building materials according to the present invention may contain plant fibers, preferably hemp shreds.

[0273] The building materials according to the present invention may include diatom frustules.

[0274] The building materials according to the present invention may have a moisture buffer value greater than or equal to 0.75; preferably greater than or equal to 1; more preferably greater than or equal to 1.2.

[0275] The building material according to the invention may have a minimum compressibility on a cylinder on day 1, measured by standard NF EN 206-1, greater than or equal to 2 MPa, preferably greater than or equal to 3 MPa, preferably greater than or equal to 5 MPa.

[0276] The building material according to the invention may have a minimum compressibility on a cylinder on the 7th day, measured by standard NF EN 206-1, greater than or equal to 8 MPa, preferably greater than or equal to 10 MPa.

[0277] Furthermore, the building materials according to the invention may have a minimum compressive strength in a cylinder at 28 days, measured by standard NF EN 206-1, less than or equal to 40 MPa, for example less than or equal to 30 MPa, and preferably less than or equal to 20 MPa, as shown in the embodiments. However, for some applications, the minimum compressive strength in a cylinder at 28 days may be much lower.

[0278] Preferably, the building material according to the invention may have a minimum compressive strength in a cylinder over 28 days, measured by standard NF EN 206-1, ranging from 10 to 30 MPa, preferably from 10 to 20 MPa.

[0279] The building material according to the invention can be formed from a building binder comprising excavated soil including the raw clay matrix.

[0280] The building adhesive according to the present invention can be used to manufacture:

[0281] - Insulating building materials: according to the present invention, the binder and the lightweight granular material of the "plant or porous" type;

[0282] - Mortar and concrete applied by dry or wet spraying methods

[0283] -Pouring concrete / mortar,

[0284] - Compacted concrete / mortar,

[0285] -Extruded concrete / mortar,

[0286] -Concrete foam,

[0287] - Lightweight concrete: The building binder according to the invention may include, for example, straw, rice husk, hemp chips, seaweed, sawdust, sunflower, Sargassum, reed, wheat husk or other grains and mixtures thereof;

[0288] -Fiber-reinforced concrete containing carbon fiber, glass fiber, polyropylene fiber, flax fiber, hemp fiber, yucca fiber, jute fiber, kenaf fiber, Mauritania amelodesmos fiber, coconut fiber, oil palm fiber, date palm fiber, banana fiber, and pineapple fiber...

[0289] High-temperature performance concrete,

[0290] -Liquid screed base layer, mortar,

[0291] - Building systems or prefabricated components: Concrete blocks or slabs, such as posts, manufactured in a factory using the binder according to the invention, particularly including silica fume, earthen concrete, timber frame / earthen concrete couplings, earthen mortar walls, reinforced earthen concrete, and...

[0292] - Insulation module.

[0293] The present invention also relates to the use of the building adhesive according to the invention in the production of composite materials or precast blocks.

[0294] Composite materials are building panels such as precast panels, while precast blocks are such as doors or curtains, precast wall elements, or any other precast building elements.

[0295] Therefore, the present invention specifically relates to prefabricated elements that can be formed from the building adhesive according to the invention. Advantageously, the prefabricated elements will be formed from the building adhesive according to the invention.

[0296] Preferably, the prefabricated element, such as a partition, has a surface area of ​​at least 1m². 2 More preferably at least 1.5m 2 Or even more preferably at least 2m 2 face.

[0297] Furthermore, the thickness of the prefabricated components can be between 0.3 cm and 20 cm, advantageously between 0.5 cm and 10 cm, and more preferably between 1 cm and 7 cm.

[0298] Such prefabricated elements advantageously have a moisture buffer value greater than or equal to 0.75, preferably greater than or equal to 1, more preferably greater than or equal to 1.2, and even more preferably greater than or equal to 1.5. When the prefabricated element has a surface area of ​​at least 1 m²... 2 More preferably at least 1.5m 2 or even better, at least 2m 2 This is especially useful when making noodles.

[0299] Furthermore, the present invention is particularly applicable to such prefabricated elements when they involve excavated clay soil.

[0300] In particular, the building adhesive according to the invention is especially suitable for partition manufacturing methods. In fact, in order to form building walls or prefabricated partitions, it must be able to possess resistant building materials and have a rapid setting time, that is, have compressibility of at least 2 MPa after 24 hours and greater than 10 MPa after 28 days, and once dry, have an MBV greater than 0.8, preferably greater than 1.2, and for example between 0.8 and 3.

[0301] Therefore, the present invention relates to the use of the building adhesive according to the invention for manufacturing partitions, which are preferably prefabricated partitions, and even more preferably prefabricated partitions having a compressive strength of at least 2 MPa after 24 hours and greater than 10 MPa after 28 days, and having an MBV between 0.8 and 3 once dried.

[0302] Such applications may include adding fillers, such as sand or plant fibers, such as hemp chips, to the building adhesives according to the invention.

[0303] Advantageously, when using the building adhesive according to the invention, the filler accounts for 200% to 900% of the building adhesive by weight. For example, in the partition according to the invention, the building adhesive according to the invention preferably accounts for 10% to 33% of the building material by weight.

[0304] The present invention also relates to partitions prepared from the building adhesive according to the invention. Such partitions may include other biologically derived materials. In particular, when the building adhesive according to the invention is used to manufacture insulating building materials, it may include lightweight granular materials of plant origin.

[0305] The preferred embodiments of the present invention have been described in detail above.

[0306] However, the features of this embodiment, such as advantageous, particular, preferred or non-preferred features, can be combined with other embodiments presented below.

[0307] In fact, the present invention also relates to a building binder comprising a raw clay matrix, an antiflocculator, and an activating component, characterized in that it has a minimum compressibility on a cylinder of greater than or equal to 12 MPa, preferably greater than 15 MPa, measured by standard NF EN 206-1 over 28 days, and a moisture buffer value of greater than or equal to 0.7, preferably greater than or equal to 1, more preferably greater than or equal to 1.2, and even more preferably greater than or equal to 1.5. Advantageously, the building binder will also include a calcined metal oxide component. In particular, the present invention relates to a building adhesive comprising a raw clay matrix, an antiflocculator, and an activating component, said building adhesive allowing the preparation of building materials having a minimum compressibility on a cylinder of greater than or equal to 12 MPa, preferably greater than 15 MPa, measured at 28 days according to standard NF EN 206-1, and a moisture buffer value of greater than or equal to 0.7, preferably greater than or equal to 1, more preferably greater than or equal to 1.2, and even more preferably greater than or equal to 1.5, measured no earlier than 10 days and preferably 28 days after manufacture. Advantageously, the building adhesive will further comprise a calcined metal oxide component.

[0308] The present invention also relates to a building adhesive comprising a raw clay matrix, an antiflocculation agent, and an activating component, wherein the raw clay matrix comprises a mixture of at least two types of clay, preferably comprising at least montmorillonite. More preferably, the two types of clay have a content of at least 30 m³. 2 / g, preferably at least equal to 50m 2 / g, more preferably greater than 100m 2 Specific surface area per g.

[0309] Even more preferably, the present invention relates to a building binder comprising a raw clay matrix, an antiflocculation agent, and an activating component, characterized in that the raw clay matrix comprises a mixture of at least two types of clay, such as montmorillonite, and the binder further comprises a calcined metal oxide component. Advantageously, the calcined metal oxide component is blast furnace slag. Preferably, the building binder comprises at least 20% by weight of the calcined metal oxide component, more preferably at least 20% by weight of blast furnace slag.

[0310] The present invention also relates to a building adhesive comprising a raw clay matrix, an antiflocculation agent, an activating component, and a calcined metal oxide component, characterized in that the antiflocculation agent comprises lignin sulfonate (ester), polyacrylate (ester), humate (ester), or a mixture thereof.

[0311] The present invention also relates to a building adhesive comprising a raw clay matrix, an antiflocculation agent, an activating component, and a calcined metal oxide component, characterized in that it comprises 30% to 70% by weight, preferably 40% to 60% by weight, of a raw clay matrix, and has the following properties:

[0312] - Less than 6, preferably less than 4, and preferably a ratio between 1 and 3 (raw clay matrix) / (calcined metal oxide component); and

[0313] - A ratio greater than 12 (calcined metal oxide component) / (antiflocculator); and

[0314] Preferably, the calcined metal oxide component is slag obtained from metallurgy, such as blast furnace slag.

[0315] This invention also relates to a building adhesive comprising a raw clay matrix, an antiflocculation agent, an activating component, and a calcined metal oxide component, characterized in that it comprises:

[0316] -30% to 70% by weight, preferably 40% to 60% by weight, of raw clay matrix;

[0317] -15% to 45% by weight, preferably 20% to 40% by weight, of the calcined metal oxide component;

[0318] Preferably, the raw clay matrix comprises at least two types of clay.

[0319] As shown in the embodiments below, the present invention provides a solution based on a mixture of raw clay matrix, antiflocculator and activating component to provide a building adhesive with mechanical properties similar to the standard while having a reduced carbon footprint.

[0320] Example:

[0321] Preparation of building adhesives:

[0322] In all the embodiments presented below, the formulations according to the invention are prepared according to the same procedure, i.e., a predetermined amount of interferomixing is performed between the raw clay matrix, the antiflocculator, and the activating component, followed by the addition of water and mixing of the solution at a low speed, i.e., essentially at 60 rpm for 30 seconds. Sand is then added to the premix, and all materials are mixed at a higher speed, i.e., at approximately 120 rpm for one minute.

[0323] Adjust the water-to-dry matter mass ratio of the composition (also known as a building adhesive) to a value between 0.4 and 0.6.

[0324] In a particular embodiment, the building material, mortar, comprises 25% by weight of binder and 75% by weight of sand; water is added to the mixture to adjust the mass ratio of water to dry matter of the binder to a value of 0.5.

[0325] The mortar based on the building adhesive thus formed is then poured into a mold and left to mature at room temperature, that is, about 20 degrees Celsius, for 28 days.

[0326] Alternatively, the mortar can be poured into a mold and then cured in a curing step at room temperature, i.e., about 25°C, or preferably under heat treatment for less than 24 hours. During this curing step, the mold can be made airtight, or the cured product can be used to cover the top layer of the building material to limit / prevent evaporation.

[0327] Methods for measuring the mechanical properties of building adhesives:

[0328] Once maturation is complete, mechanical resistance is measured. The mechanical strength of a building adhesive refers to its resistance to compression, which is measured according to standard NF EN 196-1 for a prism 40 mm wide and 160 mm long, and is expressed in megapascals (MPa).

[0329] Methods for measuring MBV values:

[0330] Moisture buffer value can be measured by any method known to those skilled in the art. For example, those skilled in the art may refer to the method described in "Durability and hygroscopic behaviour of biopolymer stabilized earthhen construction materials" Construction and Building Materials 259 (2020). Samples are placed in a climate chamber at 23°C and 33% relative humidity and left until their mass is constant (e.g., MHE 612 type climate chamber). All samples are equilibrated after being stored under these conditions for 15 days. Samples are then exposed to a high humidity cycle (75% RH, 8 hours) followed by a low relative humidity cycle (33% RH, 16 hours). Samples are periodically weighed using a precise laboratory balance, accurate to 0.01 g. After two stabilization cycles, samples are removed from the climate chamber.

[0331]

[0332] Where Δm is the change in sample mass caused by the change in relative humidity, S is the total exposed surface area, and Δ%RH is the difference between humidity levels.

[0333] Comparison of the building adhesive according to the present invention with known building adhesives:

[0334] Table 2 below shows known formulations and formulations according to the present invention for different types of building adhesives. The mass of the components associated with each formulation is expressed as a percentage (dry weight) of the total mass of the building adhesive.

[0335] [Table 2]

[0336]

[0337] Therefore, Table 2 lists the mechanical strengths of known building adhesives (adhesive CEM1) that are not part of this invention, such as the CEM1 type building adhesive more widely known as "Portland" cement, which has a compressive strength of approximately 45 MPa. It also lists the calculated moisture buffer values ​​(MBV = 0.41) for these building materials in the prior art.

[0338] Table 2 also lists formulation MUP1 according to the invention. It is worth noting that this formulation includes 1% antiflocculation agent, and although it includes a small proportion of raw clay matrix (20%), it has the same mechanical resistance as Portland cement, but much higher hygroscopic properties (MBV = 0.88).

[0339] Furthermore, while the MBV of MUP1, which contains 20% by weight of montmorillonite, is greater than 0.75 (0.88), the MBV of MUP0, which contains 10% by weight of montmorillonite and 10% by weight of kaolinite, is below the limit of 0.75.

[0340] Similarly, MUP-Y0, which contains approximately 40% kaolinite, is not allowed to reach an MBV value greater than or equal to 0.75, while MUP-Y1, which contains approximately 40% montmorillonite, is allowed to reach an MBV value of 1.4.

[0341] Therefore, montmorillonite clays are highly advantageous for preparing building materials with the ability to improve the comfort of residents through heat and moisture regulation and water buffering capacity.

[0342] Table 2 also shows clay mixtures (MUP-Y2), such as a 50 / 50 mixture of montmorillonite and kaolinite, which allow for a significant improvement in water buffering capacity (MBV = 1.3) while maintaining high compressive strength.

[0343] Regarding the low efficiency of adding raw clay to CEM1:

[0344] Table 3 below lists known cement formulations CEM1-X1 with added antiflocculating agents, and five cement formulations CEM1-X2, CEM1-X3, CEM1-X4 and CEM1-X5 with clay added in different proportions.

[0345] [Table 3]

[0346]

[0347] CEM1-X1 achieves very high mechanical strength, but its MBV is insufficient (<0.75).

[0348] Surprisingly, even in the presence of anti-flocculating agents, the addition of 20% raw clay resulted in a reduction in the hygroscopic properties of the building materials as well as a reduction in mechanical resistance.

[0349] The combination of 40% raw clay (CEM1-X3) with cement CEM1 and antiflocculation agent showed that the MBV increased compared to CEM1-X1, but remained insufficient (<0.75). Furthermore, the mechanical properties of building material CEM1-X5 were strongly affected, reaching a deficiency level (<10).

[0350] Therefore, the combination of raw clay, CEM1, and antiflocculation agent does not allow for the production of binders that simultaneously possess satisfactory MBV and mechanical strength properties.

[0351] The importance of blast furnace slag:

[0352] Table 4 below lists the reference formulation MUPZ0, the formulation MUPZ1 according to the present invention, and the formulation MUPZ2 according to the present invention.

[0353] [Table 4]

[0354]

[0355] Table 2 shows that replacing Portland cement with activated components and calcined metal oxide components (e.g., blast furnace slag type or ash) allows compositions MUPZ1 and MUPZ2 to achieve MBVs well above 0.75.

[0356] Furthermore, the composition MUPZ2, which includes an organic antiflocculating agent, has an MBV of almost 2 and a compressive strength greater than 25 MPa.

Claims

1. A building adhesive comprising a raw clay matrix, an antiflocculating agent, and an alkaline activating component, characterized in that: -It contains 10% to 30% by dry weight of the alkaline activating component; - It contains at least 40% by weight of a raw clay matrix, and the raw clay matrix includes at least one type of raw clay from the montmorillonite family; the at least one type of raw clay from the montmorillonite family accounts for at least 20% by weight of the building adhesive; - The building adhesive contains less than 15% by weight Portland cement, and It comprises at least 20% by weight of calcined metal oxide components.

2. The building adhesive according to claim 1, characterized in that... The raw clay matrix comprises a mixture of at least two types of clay.

3. The building adhesive according to claim 1 or 2, characterized in that... The raw clay matrix includes at least one having a thickness of at least 100 m³ as measured according to standard NFP 94-068. 2 Clay with a specific surface area of ​​ / g.

4. The building adhesive according to any one of claims 1 or 2, characterized in that... It has a mass ratio of the raw clay matrix to the calcined metal oxide component that is greater than or equal to 1.

5. The building adhesive according to any one of claims 1 or 2, characterized in that... The activating component comprises at least 40% by weight of at least one metal oxide corresponding to an oxide of a metal having at least two valence electrons.

6. The building adhesive according to any one of claims 1 or 2, characterized in that... The antiflocculation agent is an organic compound.

7. The building adhesive according to any one of claims 1 or 2, characterized in that... It contains excavated soil including the raw clay matrix.

8. A building material capable of being formed from the building adhesive according to any one of claims 1 to 7, comprising: - At least 2% by weight of at least one type of raw clay from the montmorillonite group, - Portland cement less than 3.75% by weight, - At least 2% by weight of calcined metal oxide components, It also has a moisture buffer value of 0.75 or greater, measured no earlier than 10 days after manufacturing.

9. The building material according to claim 8, characterized in that... It includes at least two types of raw clay.

10. The building material according to any one of claims 8 or 9, characterized in that... It includes at least 5% by weight of at least one metal oxide corresponding to an oxide of a metal having at least two valence electrons.

11. The building material according to any one of claims 8 or 9, characterized in that... The building material has a minimum compressive strength of 2 MPa on a cylinder on day 1, as measured by standard NF EN 206-1.

12. A prefabricated element capable of being formed from a building adhesive according to any one of claims 1 to 7, said prefabricated element: -Having a surface area of ​​at least 1m 2 And the surface thickness ranges from 0.3cm to 20cm; -Including at least 5% by weight of at least one type of raw clay from the montmorillonite group, -Including less than 3.75% Portland cement by weight, and - At least 2% by weight of calcined metal oxide components, - Has a moisture buffer value greater than or equal to 0.75, measured no earlier than 10 days after manufacturing.

13. A method (100) for producing precast components, the precast components being prepared from a building binder comprising a raw clay matrix, an alkaline activating component, and an antiflocculating agent, the method (100) comprising: - Provides (110) a building binder comprising a raw clay matrix, an antiflocculator, and an alkaline activating component, wherein the raw clay matrix comprises at least one raw clay from the montmorillonite group; the building binder comprises 10% to 30% dry weight of the alkaline activating component; the at least one raw clay from the montmorillonite group comprises at least 20% by weight of the building binder; at least 20% by weight of a calcined metal oxide component; and the building binder comprises less than 15% by weight of Portland cement. - Mix the building adhesive with granules and water (120), and - Step (130) of curing the mixture, wherein the curing step (130) includes heat treatment of the mixture for a duration of 2 to 23 hours.

14. The method (100) for producing prefabricated components according to claim 13, characterized in that... The raw clay matrix comprises a mixture of at least two types of clay.

15. The method (100) for producing prefabricated components according to claim 13 or 14, characterized in that... The raw clay matrix includes at least one having a thickness of at least 100m. 2 Clay with a specific surface area of ​​ / g.

16. The method (100) for producing prefabricated components according to any one of claims 13 or 14, characterized in that... The building adhesive contains at least 40% by weight of raw clay matrix.

17. The method (100) for producing prefabricated components according to any one of claims 13 or 14, characterized in that... The building adhesive has a mass ratio of the raw clay matrix to the calcined metal oxide component greater than or equal to 1.

18. The method (100) for producing prefabricated components according to any one of claims 13 or 14, characterized in that... The building adhesive comprises up to 25% by dry weight of the alkaline activated component.

19. The method (100) for producing prefabricated components according to any one of claims 13 or 14, characterized in that... The antiflocculation agent is an organic compound.

20. The method (100) for producing prefabricated components according to any one of claims 13 or 14, characterized in that... The antiflocculating agent comprises up to 2% by weight of the building adhesive.

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