ADDITIVE FOR ROAD MATERIALS

Abstract

ADDITIVE FOR ROAD MATERIALS The present invention relates to an additive composition for bituminous emulsion comprising: - from 20% to 80% by weight relative to the total weight of the additive of at least one C12-C22 monoacid comprising a hydrocarbon chain, linear or branched, saturated or unsaturated and - from 20% to 80% by weight relative to the total weight of the additive of at least one C12-C22 monoacid dimer comprising a hydrocarbon chain, linear or branched, unsaturated, the total weight of monoacid(s) and monoacid dimer(s) representing at least 70% by weight, preferably at least 80% by weight, preferably 90% by weight, relative to the total weight of the additive.

Description

Title of the invention: ADDITIVE FOR ROAD MATERIALS

[0001] The present invention relates to an additive for a bituminous emulsion. The present invention also relates to a bituminous emulsion comprising bitumen, water, an emulsion, and said additive. The present invention also relates to a cold-applied asphalt mix composition comprising said bituminous emulsion and aggregate. The present invention also proposes a use for cold-applied asphalt mix in road applications.

[0002] In the road construction industry, road surfaces are of importance and must meet a number of criteria. The surface must be easy to apply while being resistant to wear and tear from time, weathering, and vehicle traffic.

[0003] Bituminous coatings are generally used to fulfill these functions. They are obtained by coating, which involves bringing bituminous binders into contact with aggregates. These binders generally and most often correspond to the heaviest portion recovered during the petroleum distillation process and to products obtained from the extraction of tar and oil sands. The aggregates are generally divided mineral materials produced in quarries, asphalt pavement aggregates, milled asphalt, bottom ash, slag, blast furnace slag, and recycled concrete from demolition.

[0004] Several techniques for preparing bituminous road materials called asphalt mixes are well known to those skilled in the art.

[0005] Hot mix techniques use temperatures above 100°C (typically 150°C-170°C) allowing the necessary fluidization of an anhydrous bituminous binder for homogeneous mixing with aggregates in order to obtain so-called hot mix asphalt.

[0006] So-called warm techniques are similar to the operations of so-called hot techniques by employing temperatures 10°C to 40°C lower than hot techniques.

[0007] These so-called hot and warm techniques therefore require a heat input, resulting in additional energy costs. Furthermore, the preparation of bituminous materials at high temperatures gives rise to the emission of fumes harmful to workers and local residents.

[0008] So-called cold techniques use lower temperatures than so-called hot or warm techniques (typically 20°C to 60°C lower). These methods thus make it possible to reduce, or even avoid, the production of these fumes while minimizing the additional energy cost.

[0009] So-called cold techniques include the mixing of an aqueous-phase bituminous emulsion and aggregates. A mixture of bituminous emulsion and aggregates just before laying results in the formation of cold-applied asphalt mixes (also called cold-applied bituminous materials), while a mixture of these constituents in a storage plant gives rise to stockpiled asphalt, emulsion-treated aggregate, and emulsion-treated asphalt concrete.

[0010] Cold-applied bituminous materials (CFBMs) are considered road materials as described in the information note from the Technical Studies Service for Roads and Highways (SETRA) of the Roads Directorate of the Ministry of Equipment (Information Note on Roads and Dependencies No. 102 "Cold-Applied Asphalt" of June 1997), or in the guidelines published in May 2003 by the International Slurry Surfacing Association (Annapolis, MD, USA). CFBMs are understood here to include all variants of this technology.

[0011] Cold bituminous concrete (BBF) and emulsion-aggregates are respectively defined in standard NF P 98-139 and in standard NF P 98-121. Stockpilable asphalt mixes correspond to cold asphalt mixes that can be stored for several weeks or several months and are generally used for road maintenance.

[0012] The bituminous binder (or bituminous phase) is understood to mean natural bitumen, bitumens derived from mineral oil, bitumens derived from cracking, tar, blown bitumens, bitumens diluted with petroleum solvents, bitumens diluted with vegetable oils or any resulting mixture.

[0013] Bituminous emulsions are generally obtained by mixing a bituminous binder and at least one aqueous phase additive.

[0014] An emulsion is a mixture of a heterogeneous system composed of at least two immiscible liquids, in which fine droplets of one of the liquids are dispersed in the continuous phase of the other liquid. Thus, a bitumen emulsion is equivalent to the dispersion of a bituminous phase in an aqueous phase in the presence of at least one additive such as a surfactant, emulsifier, thickener, fluxing agent, plasticizer, or other additive that allows adjustment of the emulsion.

[0015] Cold-poured asphalt mixes must possess a number of characteristics in order to be considered efficient.

[0016] When implementing asphalt as a road surface in the form of a wearing course for the renovation or repair of roads, a good rise in cohesion corresponding to a satisfactory adhesion between bitumen and aggregate is necessary (with or without external stress) in order to allow the surface to support traffic.

[0017] This cohesion is obtained by compacting the material accompanied by the expulsion of the aqueous phase of the emulsion and air.

[0018] In summary, in the case of cold mix asphalt, applicators seek: good stability of the bituminous emulsion during the mixing of the asphalt allowing correct laying, good coating of the aggregate by the bitumen in all stages of the process, good bitumen / aggregate adhesion properties as well as sufficient cohesion and rapid setting of the asphalt to allow rapid opening to traffic without risking road degradation (tearing, cracking and others).

[0019] Bituminous emulsion additives play a key role in obtaining the desired characteristics of the final asphalt mix, and the simple use of surfactants does not allow these to be obtained.

[0020] It is known to those skilled in the art that the use of fatty acids in the form of polymerized fatty acids or of polymers having a carboxylic acid function as additives (also called dopes) makes it possible to improve the bitumen / aggregate adhesion and / or the increase in cohesion.

[0021] Polymerized fatty acids are acids resulting from the polymerization of chains of at least two unsaturated fatty acids having 12 to 22 carbon atoms.

[0022] Document FR2930253 describes a bituminous emulsion comprising one or more polymerized fatty acids, preferably in the form of fatty acid dimers or trimers for a cold-mix asphalt.

[0023] Document FR3017385 proposes a cationic bituminous emulsion of bitumen comprising at least one alkylpropylene polyamine, phosphoric acid (specific surfactant / mineral acid pair), and a fatty acid doper. The fatty acids considered are in particular fatty acid dimers or fatty acid trimers. This bituminous emulsion is used for the preparation of a cold-applied bituminous material.

[0024] Document EP0416682 relates to a bitumen composition comprising at least one polymerized fatty acid and its use in a bituminous emulsion or surface coatings.

[0025] US2632712 relates to bituminous compositions comprising a polymerized unsaturated fatty acid for road construction.

[0026] Document EP0227238 proposes a bituminous composition comprising a fatty acid (with a C10 to C30 chain) such as stearic acid, palmitic acid or oleic acid.

[0027] Document WO2020193692 describes a cationic bitumen emulsion comprising an additive corresponding to a thermoplastic polymer having at least one carboxylic acid function.

[0028] However, it is necessary to offer additives for bituminous emulsion that are easy to handle, typically pumpable, and increasingly efficient. enabling the desired characteristics of the final cold-poured bituminous mix to be obtained.

[0029] The inventors discovered that a particular mixture of fatty acids exhibited a viscosity that made the mixture pumpable, thus facilitating its industrial use. Furthermore, the inventors showed that this specific additive maintains a sufficiently long emulsion stability time, resulting in easy mixing for the application of the asphalt mix (breaking time). In addition, this additive contributes to improving the cohesion development of cold-applied asphalt mix. Brief description of the invention

[0030] The present invention relates to an additive for bituminous emulsion comprising - from 20% to 80% by weight relative to the total weight of the additive - of at least one monoacid in the C12-C22 range, inclusive, comprising a hydrocarbon chain, linear or branched, saturated or unsaturated and -from 20% to 80% by weight relative to the total weight of the additive of at least one dimer of monoacid(s) in C12-C22, inclusive, comprising a linear or branched, unsaturated hydrocarbon chain, the total weight of monoacid(s) and monoacid(s) dimer(s) representing at least 70% by weight, preferably at least 80% by weight, preferably even at least 90% by weight, relative to the total weight of the additive.

[0031] The invention also relates to a use of the additive for preparing a bituminous emulsion. The present invention also relates to a bituminous emulsion comprising bitumen and an aqueous phase, including the additive according to the invention. The present invention also relates to a method for preparing the bituminous emulsion. The present invention also relates to a cold-poured asphalt mix comprising the bituminous emulsion and aggregate. The present invention also relates to a method for preparing cold-poured asphalt mix from a mixture of the bituminous emulsion with aggregate at temperatures of 60°C or lower. The present invention also proposes a use of the cold-poured asphalt mix in road applications.

[0032] Other advantageous characteristics of the additive according to the invention are specified below. -The C12-C22 monoacid comprises a linear or branched, unsaturated hydrocarbon chain. -The dimer comprises a linear or branched, unsaturated hydrocarbon chain. -The additive has a monoacid content of between 25 and 75% by weight relative to the total weight of the additive and a dimer content of between 25 and 75% by weight relative to the total weight of the additive. -The weight ratio between monoacid:dimer is between 3:1 and 1:3, preferably even between 2:1 and 1:2. -The additive has an acid value between 160 and 280 mg KOH / g, preferably between 180 and 260 mg KOH / g. -The additive has a viscosity of less than 1000 mPa.s at 25°C.

[0033] The invention also relates to the use of the additive as defined in one of above to prepare a bituminous emulsion.

[0034] The invention also relates to a bituminous emulsion comprising bitumen, from 0.1 to 5% by weight, preferably from 0.1 to 3% by weight and preferably from 0.3 to 2% by weight of the additive according to the invention and an aqueous phase, the aqueous phase comprising: a) water, b) at least one cationic surfactant emulsifier, the pH of the aqueous phase being between 1 and 5.5, preferably between 1.5 and 2.5.

[0035] Other advantageous characteristics of the bituminous emulsion according to the invention are specified below. -The emulsion comprises a bitumen content, preferably paraffinic, of between 30 and 70% by weight relative to the total weight of the emulsion. -The emulsion includes adjuvants chosen from thickeners, fluxers, plasticizers.

[0036] The invention relates to a use of the bituminous emulsion according to the invention to prepare a bituminous coating.

[0037] The invention also relates to a cold-poured bituminous coating obtained by mixing aggregates and a bituminous emulsion according to the invention.

[0038] The invention relates to a method for manufacturing a cold-poured bituminous mix comprising a step of mixing the bituminous emulsion as defined above with the aggregates at a temperature between 10°C and 60°C.

[0039] Finally, the invention relates to the use of bituminous mix according to the invention in road applications for manufacturing new pavements or wearing courses, for the reinforcement or maintenance of existing pavements. Detailed description of the invention

[0040] Other features, aspects, objects and advantages of the present invention will become even clearer upon reading the following description.

[0041] Unless otherwise indicated, all percentages are mass percentages.

[0042] In this text, the quantities indicated for a given species may apply to that species according to all its definitions (as mentioned in this text), including more restricted definitions.

[0043] It is specified that the expressions "from ... to ..." and "between ... and...." used in this description should be understood as including each of the limits mentioned. Additive

[0044] The additive for bituminous emulsion according to the invention comprises: -from 20% to 80% by weight relative to the total weight of the additive of at least one C12-C22 monoacid comprising a linear or branched, saturated or unsaturated hydrocarbon chain and -from 20% to 80% by weight relative to the total weight of the additive of at least one C12-C22 monoacid dimer comprising a linear or branched unsaturated hydrocarbon chain, the total weight of monoacid(s) and monoacid dimer(s) representing at least 70% by weight, preferably at least 80% by weight, preferably 90% by weight, relative to the total weight of the additive.

[0045] The composition according to the invention comprises at least one C12-C22 monoacid comprising a linear or branched, saturated or unsaturated hydrocarbon chain. These fatty acids are well known to those skilled in the art. Preferably, the monoacid comprises from 14 to 22 carbon atoms (C4 to C22), and more preferably from 16 to 18 carbon atoms (C16 to C18).

[0046] Preferably, the monoacid is selected from lauric acid (C12), dodecenoic acid (C12), tridecyl acid (C13), myristic acid (C14), myristoleic acid (C14), pentadecyl acid (C15), palmitic acid (C16), palmitoleic acid (C16), hiragonic acid (C16), sapienic acid (C16), margaric acid (C17), stearic acid (C18), calendic acid (C18), rumenic acid (C18), oleic acid (C18), elaidic acid (C18), vaccenic acid (C18), petroselinic acid (C18), linoleic acid (C18), linolenic acid (C18), γ-linolenic acid (C18), eleostearic acid (C18), parinaric acid (C18), linolelaidic acid (C18), pinolenic acid (C18), nonadecylic acid (C19), arachidic acid (C20), jacaric acid (C20), stearidonic acid (C20), arachidonic acid (C20), gadoleic acid (C20), gondoic acid (C20), icosapentaenoic acid (C20), dihomo-γ-linolenic acid (C20),Arachidonic acid (C20), brassidic acid (C22), erucic acid (C22), ketolic acid (C22), clupanodonic acid (C22), tuberculostearic acid (C19), phytanic acid (C20) taken alone or in mixtures.

[0047] Preferably, the monoacid present in the additive according to the invention is a C12-C22 monoacid comprising a linear or branched, unsaturated hydrocarbon chain.

[0048] Preferably, the monoacid comprising the unsaturated hydrocarbon chain is selected from dodecenoic acid (C12), myristoleic acid (C14), palmitoleic acid (C16), hiragonic acid (C16), sapienic acid (C16), calendic acid (C18), rumenic acid (C18), oleic acid (C18), elaidic acid (C18), vaccenic acid (C18), petroselinic acid (C18), linoleic acid (C18), linolenic acid (C18), γ-linolenic acid (C18), eleostearic acid (C18), parinaric acid (C18), linolelaidic acid (C18), pinolenic acid (C18), jacaric acid (C20), stearidonic acid (C20), arachidonic acid (C20), gadoleic acid (C20), gondoic acid (C20), icosapentaenoic acid (C20), dihomo-y-linolenic acid (C20), arachidonic acid (C20), brassidic acid (C22), erucic acid (C22), ketolic acid (C22), clupanodonic acid (C22), taken alone or in mixtures.

[0049] The content of monoacid(s) as described above is between 20 and 80% by weight relative to the total weight of the additive, advantageously between 25 and 75% by weight, more advantageously between 35 and 65% by weight and even more advantageously between 45 and 55% by weight.

[0050] The monoacid of the additive according to the invention is preferably chosen from: -the product with CAS number 61790-12-3 derived from pine oil (known as Tall Oil Fatty Acid or TOFA). This product includes mono-fatty acids such as oleic acid (Cl8) and linolenic acid (Cl8). - the product with CAS number 67701-08-0 derived from soybean oil. This product includes oleic acid (C18), linoleic acid (C18), linolenic acid (C18), palmitic acid (C16) and stearic acid (C18), - the product of CAS number 120962-03 derived from canola oil, - the product of CAS number 8002-13-09 derived from rapeseed oil, - the product of CAS number 8001-30-7 derived from corn oil, - the product of CAS number 8002-03-7 derived from peanut oil.

[0051] The additive according to the invention also comprises at least one C12-C22 monoacid dimer comprising an unsaturated, linear or branched hydrocarbon chain.

[0052] Preferably, the unsaturated fatty acids used to obtain the dimerized fatty acids are generally and most often unsaturated fatty acids of 12 to 22 carbon atoms (C12 to C22), preferably of 14 to 22 carbon atoms (C14 to C22), preferably of 16 to 18 carbon atoms (C16 to C18).

[0053] Preferably, a fatty acid dimer is a dimer formed from two monoacids possessing a monounsaturated or polyunsaturated hydrocarbon chain. Therefore, this dimer is a C24-C44 diacid.

[0054] It is possible to polymerize a fatty acid or a mixture containing several different fatty acids. This reaction, which allows the polymerization of the fatty acid chains, is generally a Diels-Alder reaction leading to a C6 ring (for more information see Kirk Othmer Encyclopedia of Chemical Technology, Vol. 7, p. 768 or "The dimer acids", Humko Sheffield, 1975).

[0055] Preferably, the additive comprises a mixture of dimerized fatty acids (linear C18 monoacid dimers and unsaturated) of CAS number 61788-89-4.

[0056] The content of monoacid(s) dimer(s) is between 20 and 80% by weight relative to the total weight of the additive, preferably 25 and 75% by weight, more advantageously between 35 and 65% by weight and even more advantageously between 45 and 55% by weight.

[0057] Preferably, the additive comprises a monoacid content of between 25 and 75% by weight relative to the total weight of the additive and a monoacid dimer content of between 25 and 75% by weight relative to the total weight of the additive.

[0058] The additive according to the invention comprises at least 70% by weight relative to the total weight of the additive, preferably at least 80%, more preferably at least 90% by weight of one or more monoacids and one or more dimers as defined above.

[0059] Preferably, the additive consists of a monoacid content of between 25 and 75% by weight relative to the total weight of the additive and a dimer content of between 25 and 75% by weight relative to the total weight of the additive.

[0060] Preferably, the weight ratio between monoacid:dimer is between 3:1 and 1:3, more preferably between 2:1 and 1:2.

[0061] Preferably, the additive does not contain any polymerized acid(s), for example, acid trimers, with the exception of the dimers described above. The sum of the weight contents of monoacid(s) and diacid(s) represents 100% by weight of the total weight of the additive, within measurement errors and excluding impurities.

[0062] Preferably, the additive has a viscosity of less than 1000 mPa.s at 25°C measured using an Anton Paar MCR301 rheometer with a 25 mm diameter plan-plan device, a 1 mm gap and a shear rate of 100 s1, the viscosity of the additive is advantageously less than 900 mPa.s, more advantageously less than 600 mPa.s and even more advantageously less than 400 mPa.s.

[0063] Preferably, the additive has an acid value of between 160 and 280 mg KOH / g, preferably between 180 and 260 mg KOH / g, measured according to ISO 660 (2020).

[0064] The invention also relates to the use of the additive as defined above to prepare a bituminous emulsion. Bituminous emulsion

[0065] The invention also relates to a bituminous emulsion comprising bitumen, 0.1 to 5% by weight of the additive as defined above and an aqueous phase, the aqueous phase comprising: - water, - at least one emulsifier, typically a cationic surfactant type emulsifier, preferably comprising at least one amido-amine and / or polyamine function, and the pH of the aqueous phase being between 1 and 5.5, preferably between 1.5 and 2.5.

[0066] The bitumens used in the emulsion according to the present invention are bitumens from various sources. These include, firstly, bitumens of natural origin, those contained in deposits of natural bitumen, natural asphalt, or oil sands.

[0067] The bitumens according to the invention are also bitumens obtained from crude oil refining. The bitumens are obtained from atmospheric and / or vacuum distillation of petroleum. These bitumens may also be optionally oxidized, blown, viscoreduced, and / or deasphalted. The bitumens may be hard-grade or soft-grade. The different bitumens obtained by the refining processes may be combined to achieve the best technical compromise.

[0068] The bitumens used may also be fluxed bitumens by the addition of volatile solvents, petroleum-based fluxants, carbochemical fluxants and / or plant-based fluxants.

[0069] Polymer-modified bitumens can also be used. Examples of polymers include, but are not limited to, thermoplastic elastomers such as linear or star-shaped stochastic or sequence copolymers of styrene and butadiene (SBR, SBS) or of styrene and isoprene (SIS), possibly crosslinked; copolymers of ethylene and vinyl acetate; olefinic homopolymers and copolymers of ethylene (or propylene, or butylene); polyisobutylenes; polybutadienes; polyisoprenes; poly(vinyl chloride); rubber powders; or any polymer used for modifying bitumens and their mixtures. Generally, a polymer content of 2 to 10% by weight relative to the weight of bitumen is used.

[0070] Synthetic bitumens, also called clear, pigmentable, or colorable bitumens, can also be used. These bitumens contain little or no asphaltenes and can therefore be colored. These synthetic bitumens are based on petroleum resin and / or indene-coumarone resin and lubricating oil, as described, for example, in patent EP 179510.

[0071] Advantageously, the bitumen is a bitumen with a penetration capability measured according to the NF EN 1426 standard of June 2007 ranging from 10 to 300, preferably from 20 to 220, more preferably from 70 to 220.

[0072] Preferably, the bitumen according to the invention is chosen from unmodified crude oil refining bitumens.

[0073] Preferably, the bitumen used according to the invention is fresh bitumen. For the purposes of this invention, "fresh" bitumen means bitumen that has not yet been mixed with aggregates or spread. In English, fresh bitumen is called "neat bitumen".

[0074] The bitumen used according to the invention may also be a recycled bituminous product. In this case, the mineral aggregates used in asphalt mixes are generally quarry products and are increasingly used in combination with aggregates recycled from previously manufactured asphalt mixes. Such recycled aggregates are known generically as reclaimed asphalt pavement (RAP), for example, as defined in the French standard AFNOR XP P98-135 of December 2001 or in the Asphalt Handbook, MS-4, 7th edition, published by the Asphalt Institute, USA.

[0075] RAP also includes recycled asphalt mixes where the mineral aggregates are replaced in part or in full by other common components, such as, by way of limiting examples, organic and inorganic fibers (e.g. glass, metal or carbon fibers, cellulose, cotton, etc.), polymers (e.g. polypropylenes, polyesters, poly(vinyl alcohols), polyamides, polyurethanes, polyureas, ethylene-vinyl acetate (EVA) and styrene-butadiene-styrene (SBS) copolymers).

[0076] Recovered or recycled aggregates, commonly called reclaimed asphalt pavement (RAP), are of particular interest. These aggregates result from the milling, or any other grinding method, of previous asphalt mixes, generally damaged and requiring replacement. These recycled aggregates contain bitumen used as a binder during the initial manufacturing process.

[0077] Other sources of bituminous products that can also be recycled in the manufacture of asphalt mixes include, for example, roofing products (e.g., shingles or waterproofing membranes, as well as waste from their production), thermal insulation or soundproofing materials. These bituminous products generally do not contain mineral fillers.

[0078] Preferably, the bituminous emulsion comprises paraffinic bitumen.

[0079] Preferably, the emulsion according to the invention comprises 30 to 70% by weight of bitumen relative to the total weight of the emulsion.

[0080] The emulsion according to the invention comprises at least one emulsifier contributing to the stability of the emulsion.

[0081] Non-limiting examples of emulsifiers for obtaining such emulsions include alkylpolyamines, alkylamidopolyamines, alkylamidoimidazolines, quaternary alkylmonoamines, quaternary alkylpolyamines, amino derivatives of lignin obtained by direct amination or by the Mannich reaction or by reaction between Kraft lignin and glycidylamine, and the resulting mixtures. In one advantageous embodiment, the emulsifier is an alkylamidopolyamine.

[0082] Preferably, the bituminous emulsion comprises 0.1 to 3% by weight of emulsifier relative to the total weight of the bituminous emulsion, preferably 0.3 to 2% by weight and preferably 0.5 to 1.5% by weight.

[0083] Preferably, the bituminous emulsion comprises 0.1 to 5% by weight of the additive relative to the total weight of the emulsion of the additive as defined above, preferably 0.1 to 3% by weight and preferably 0.3 to 2% by weight.

[0084] Preferably, the bituminous emulsion composition may include a sufficient quantity of a mineral or organic acid other than the aforementioned monoacids and diacids, preferably a mineral acid.

[0085] The acid content is adjusted to achieve a pH of the aqueous phase of the bituminous emulsion between 1 and 5.5, preferably between 1.5 and 2.5.

[0086] In a preferred embodiment, the acid is advantageously hydrochloric acid.

[0087] The bituminous emulsion may optionally include one or more adjuvants commonly used in the field, among which, without limitation, natural or synthetic latexes, thickeners, fluxers, plasticizers, as well as any other additive allowing adjustment of the properties of the emulsion, such as the process additives mentioned in patent EP1057873 Bl.

[0088] The invention also relates to a method for preparing the bituminous emulsion comprising a step of mixing the bitumen with an aqueous phase as defined above, according to any methods well known to those skilled in the art, for example by means of a colloidal mill.

[0089] The invention also relates to a method for preparing the bituminous emulsion comprising a step of mixing the bitumen, the additive according to the invention and an aqueous phase comprising at least one emulsifier, typically a cationic surfactant type emulsifier, preferably comprising at least one amido-amine and / or polyamine function, the pH of the aqueous phase being between 1 and 5.5, preferably between 1.5 and 2.5, according to any methods well known to those skilled in the art.

[0090] The invention also relates to the use of the bituminous emulsion as defined above to prepare a bituminous coating. Cold-poured asphalt

[0091] The invention also relates to a cold-poured bituminous mix obtained by mixing aggregates and a bituminous emulsion as defined above.

[0092] The asphalt mix advantageously comprises 1 to 40% by weight relative to the total weight of the asphalt mix, preferably 3 to 30% by weight, more preferably 6 to 20% by weight and even more preferably 8 to 15% by weight of the bituminous emulsion defined above.

[0093] The invention also relates to a method for manufacturing cold-poured bituminous mix comprising a step of mixing the bituminous emulsion with the aggregates at a temperature between ambient temperature, i.e. from 10 to 40°C depending on the location and the seasons, and 60°C, according to all methods well known to those skilled in the art.

[0094] The aggregates that can be used for the preparation of asphalt mixes according to the present invention can be of any type known to those skilled in the art. Among the aggregates that can be used for the asphalt mixes of the present invention, one can notably mention, without limitation, aggregates of mineralogical nature, for example of igneous nature, such as granites, porphyries, basalts, of metamorphic nature, such as schists, gneisses, and of sedimentary nature of siliceous type, such as flints, quartzites, and of carbonate type, such as limestones, dolomites, but also asphalt (or recycled) aggregates, slags, crushed concrete, and others, as well as mixtures of such aggregates.

[0095] The emulsions of the present invention are thus particularly suitable for the preparation of asphalt mixes, for example semi-warm asphalt mixes, i.e., where the temperature of the aggregates during the mixing phase with the bitumen emulsion is between ambient temperature, which can range from 0°C to 40°C, and 60°C, for example also cold asphalt mixes, among which we can mention, without limitation, gravel emulsions (structural or reprofiling), cold bituminous concretes, dense, semi-dense or open stockpiled asphalt mixes, and others. Wearing course

[0096] The invention also relates to a method for manufacturing a bearing layer comprising the following successive steps:

[0097] 1) mixing the bituminous emulsion with the aggregates at a temperature between between ambient temperature (typically 10 to 40°C) and 60°C, 2) spreading of the bituminous coating at a temperature between ambient temperature (typically 10 to 40°C) and 40°C.

[0098] The invention also relates to the use of bituminous mix in road applications for manufacturing new pavements or wearing courses, for the reinforcement or maintenance of old pavements. Examples

[0099] Example 1: Evaluation of the viscosity of additives

[0100] Preparation of additives

[0101] The following additives were prepared according to Table 1 below. The contents are expressed as a percentage by weight: [Tables 1] Additive 1 Comparative 2 Comparative 3 Invention 4 Invention 5 Invention Cl8 mono-fatty acid dimers (CAS 61788-89-4)1 100 0 70 50 50 Mono-fatty acids (CAS 6179 0-12-3)2 0 100 30 50 0 Mono-fatty acids (CAS 6770 1-08-0)3 0 0 0 0 50

[0102] 1 The product with CAS number 61788-89-4 is a mixture of monoacid dimers fat in Cl8

[0103] 2 The product of CAS number 61790-12-3 is a mixture comprising linear and unsaturated C18 mono-fatty acids from pine oil (also known as Tall Oil Fatty Acid in English or TOFA).

[0104] 3 The product with CAS number 67701-08-0 is a mixture of mono-fatty acids C16-C18 unsaturated fats derived from soybean oil.

[0105] Evaluation of additives

[0106] The viscosity of the compositions is measured using an Anton Paar MCR501 rheometer equipped with a 25 mm plane-plane geometry. The measurement is carried out in rotation at a shear rate of 100 s1, with a gap of 1 mm, and at a temperature of 25°C.

[0107] The viscosity of the additives is shown in Table 2 below. The values ​​are expressed in mPa·s: [Tables 2] Additive 1 Comparative 2 Comparative 3 Invention 4 Invention 5 Invention Viscosity (mPa.s) 8340 15 850 220 250

[0108] The addition of mono-fatty acids to the mixture in a certain amount allows a significant reduction in the viscosity of the mixture.

[0109] The specific viscosity of the additives according to the invention 3 to 5 thus has the advantage of being much easier to use.

[0110] Example 2: Evaluation of the breaking time of the emulsion of additive-enhanced bituminous mixes and the breaking time after internal cohesion buildup of additive-enhanced bituminous mixes

[0111] Preparation of bituminous emulsions

[0112] The following bituminous mix emulsions were prepared according to Table 3 below. The contents are expressed as a percentage by weight: [Tables 3] Bituminous Emulsion 6 Comparison 7 Comparison 8 Comparison 9 Invention Bitumen 60 60 60 60 Emulsifier (Poly ram® L950) 0.9 0.9 0.9 0.9 Additive 1 0 1 0 0 Additive 2 0 0 1 0 Additive 4 0 0 0 1 HCl 0.9 0.9 0.9 0.9 Water QSP 100 QSP 100 QSP 100 QSP 100

[0113] The bitumen is 70 / 100 paraffinic bitumen marketed by the company Total and coming from the Gonfreville plant.

[0114] The amido-amine type emulsifier is marketed under the trade name Polyram®L950 by the company Arkema France.

[0115] Additives 1, 2 and 4 are those described in example 1.

[0116] The quantity of hydrochloric acid is 0.9% by weight so that the pH of the bituminous emulsion is equal to 2.

[0117] Preparation of bituminous mixtures

[0118] The following bituminous mixtures were prepared according to Table 4 below. The contents are expressed as a percentage by weight: [Tables 4] Bituminous Mix 11 Comparison 12 Comparison 13 Comparison 14 Invention Aggregate 78.5 78.5 78.5 78.5 Emulsion 6 12 - - - Emulsion 7 - 12 - - Emulsion 8 - - 12 - Emulsion 9 - - - 12 Cement 0.5 0.5 0.5 0.5 Water 9 9 9 9

[0119] The aggregate is 0 / 8 aggregate from the Ambazac quarry.

[0120] The cement is a CEM II 32.5 type cement. The term "cement" means any hydraulic binder composed of finely ground inorganic material which, when mixed with water, forms a paste which sets and hardens as a result of reactions and hydration processes and which, after hardening, retains its strength and stability even underwater (NF P98-149 (2000-06-01) standards).

[0121] Bituminous emulsions 6 to 9 correspond to the emulsions listed in Table 3.

[0122] Evaluation of bituminous mixtures

[0123] The previously prepared bituminous mixtures were tested to evaluate the breaking time and the time to rise into cohesion (Hilt Cohesion Test).

[0124] Evaluation of the rupture time

[0125] During the mixing of bituminous mixtures, the breaking time or workability time is visually assessed. This time corresponds to the time it takes for the emulsion to destabilize during mixing, that is, the time at which a change of state occurs. This test is carried out at a controlled temperature between 20 and 25°C.

[0126] Evaluation of internal cohesion as a function of maturation time

[0127] Internal cohesion as a function of ripening time is evaluated using a Hilt Cohesion Test

[0128] The Hilt Cohesion Test (HCT) is a non-standardized test described in the CEREMA guide (ISBN: 978-2-37180-202-5) on cold-cast materials in 2017.

[0129] A bituminous asphalt slab (size 120 x 120 x 14 mm) listed in Table 5 is placed on a support having a removable part. After one hour of curing, one-third of the slab is placed on the previously removable part. removed. One-third of the plate then becomes suspended in mid-air. The HCT test then consists of measuring the plate's rupture time.

[0130] The values ​​obtained are expressed in the table below: [Tables 5] Bituminous coating 11 Comparison 12 Comparison 13 Comparison 14 Invention Breakdown time (s) 90 90 90 80 Hilt Cohesion Test (s) 8 87 45 130

[0131] The emulsion breaking time remains satisfactory, despite the addition of the additive according to the invention.

[0132] The bituminous mix according to the invention (Asphalt 14), incorporating the additive as described above, exhibits a longer breaking time during the HCT test than the comparative bituminous mixes prepared: without fatty acids (Asphalt 11), or comprising only dimerized fatty acids (Asphalt 12: additive not meeting the viscosity criterion), or comprising only fatty acid monomers (Asphalt 13). The bituminous mix according to the invention has the advantage of accelerating the cohesion build-up, allowing for a faster resumption of traffic when the material is used, and includes a pumpable additive thanks to its reduced viscosity.

[0133] These examples show that the mixture of monoacids and dimers allows for a rapid rise in cohesion, without significantly altering the breaking time.

[0134] Example 3: Time for internal cohesion to rise in bituminous mixtures at 20°C with paraffinic bitumens and aggregates from different sources

[0135] Preparation of bituminous emulsions

[0136] The following bituminous emulsions were prepared according to Table 6 below. The contents are expressed as a percentage by weight: [Tableauxô] Bituminous Emulsion 15 Comparative 16 Invention 17 Comparative 18 Invention Bitumen 1 (Total Gonfreville) 60 60 0 0 Bitumen 2 (Total Antwerp) 0 0 60 60 Emulsifier (Polyram® L950) 0.9 0.9 0.9 0.9 Additive 1 1 0 1 0 Additive 4 0 1 0 0 Additive 5 0 0 0 1 HCl 0.9 0.9 0.9 0.9 water QSP 100 QSP 100 QSP 100 QSP 100

[0137] Bitumen 1 is 70 / 100 paraffinic bitumen marketed by the company Total and coming from the Gonfreville plant.

[0138] Bitumen 2 is 70 / 100 paraffinic bitumen marketed by the company Total and coming from the Antwerp plant.

[0139] The quantity of hydrochloric acid is 0.9% by weight so that the pH of the bituminous emulsion is equal to 2.

[0140] The amido-amine type emulsifier is marketed under the trade name Polyram®L950 by the company Arkema France.

[0141] Additives 1, 4 and 5 are defined in Example 1.

[0142] Preparation of bituminous mixtures

[0143] The following bituminous mixtures were prepared according to Table 7 below. The contents are expressed as a percentage by weight: [Tables 7] Bituminous Mixture 19 Comparison 20 Invention 21 Comparison 22 Invention Aggregate 1 (Ambazac) 78.5 78.5 78.5 78.5 Emulsion 15 12 0 0 0 Emulsion 16 0 12 0 0 Emulsion 17 0 0 12 0 Emulsion 18 0 0 0 12 Cement 0.5 0.5 0.5 0.5 Water 9 9 9 9

[0144] Aggregate 1 is 0 / 8 aggregate from the Ambazac quarry.

[0145] The cement is a CEM II 32.5 type cement. "Cement" means any binder hydraulic compound made of finely ground inorganic material which, when mixed with water, forms a paste which sets and hardens as a result of reactions and hydration processes and which after hardening retains its strength and stability even underwater (NF P98-149 standards (2000-06-01)).

[0146] Evaluation of asphalt mixes

[0147] The previously prepared bituminous mixtures were tested to evaluate the breaking time using the Hilt Cohesion Test. The values ​​obtained are expressed in Table 8 below: [Tables 8] Bituminous coating 19 Comparison 20 Invention 21 Comparison 22 Hilt Invention Cohesion Test(s) 90 130 80 160

[0148] The bituminous mixes according to the invention (Mixes 20 and 22) exhibit a longer failure time during the HCT test than the comparative bituminous mixes prepared without fatty acids (Mixes 19 and 21). The bituminous mixes according to the invention have the advantage of accelerating cohesion development, allowing for a faster resumption of traffic when the material is used, and include a pumpable additive thanks to its reduced viscosity.

Claims

Demands

1. Bituminous emulsion additive comprising: - 20% to 80% by weight relative to the total weight of the additive of at least one C12-C22 monoacid comprising a hydrocarbon chain, linear or branched, saturated or unsaturated and - 20% to 80% by weight relative to the total weight of the additive of at least one C12-C22 monoacid dimer comprising a hydrocarbon chain, linear or branched, unsaturated, the total weight of monoacid(s) and monoacid dimer(s) representing at least 70% by weight, preferably at least 80% by weight, preferably 90% by weight, relative to the total weight of the additive.

2. Additive according to claim 1, characterized in that the C12-C22 monoacid comprises an unsaturated, linear or branched hydrocarbon chain.

3. Additive according to any one of the preceding claims, characterized in that it comprises a monoacid content of between 25 and 75% by weight relative to the total weight of the additive and a dimer content of between 25 and 75% by weight relative to the total weight of the additive.

4. Additive according to any one of the preceding claims, characterized in that the weight ratio between monoacid :dimer is between 3:1 and 1:3, preferably also between 2:1 and 1:

2.

5. Additive according to any one of the preceding claims, characterized in that it has an acid value of between 160 and 280 mg KOH / g, preferably between 180 and 260 mg KOH / g.

6. Additive according to any one of the preceding claims, characterized in that it has a viscosity of less than 1000 mPa.s at 25°C.

7. Use of the additive as defined in any one of claims 1 to 6 to prepare a bituminous emulsion.

8. Bituminous emulsion comprising bitumen, from 0.1 to 5% by weight, preferably from 0.1 to 3% by weight and preferably from 0.3 to 2% by weight of the additive as defined in any one of claims 1 to 6 and an aqueous phase, the aqueous phase comprising: a) water, b) at least one cationic surfactant emulsifier, the pH of the aqueous phase being between 1 and 5.5, preferably between 1.5 and 2.

5.

9. Emulsion according to claim 8, characterized in that it comprises a bitumen content, preferably paraffinic, of between 30 and 70% by weight relative to the total weight of the emulsion.

10. Emulsion according to claim 8 or 9, characterized in that it comprises adjuvants selected from thickeners, fluxers, plasticizers.

11. Use of the bituminous emulsion as defined in any one of claims 8 to 10 to prepare a bituminous mix.

12. Cold-poured bituminous mix comprising aggregates and a bituminous emulsion as defined in any one of claims 8 to 10.

13. A method for manufacturing a cold-poured bituminous mix comprising a step of mixing the bituminous emulsion as defined in claims 8 to 10 with the aggregates at a temperature between 10°C and 60°C.

14. Use of bituminous mix as defined in claim 12 in road applications for manufacturing new pavements or wearing courses, for the reinforcement or maintenance of old pavements.