Compact hydrocarbon mixes with improved workability and compactness properties

Abstract

This disclosure relates to a compacted asphalt mix comprising a hydrocarbon binder and solid particles. The asphalt mix comprises 0.1 to 5% by weight, relative to the weight of the hydrocarbon binder, of a thermoplastic additive selected from a polymer having at least one carboxylic acid terminus, the polymer being a polyester, a polyamide, a poly(ester-amide), a polyether functionalized at the end of a carboxylic acid chain, or a polydiene functionalized at the end of a carboxylic acid chain; or a thermoplastic polymer functionalized at the end of a chain with a succinic anhydride group, the polymer being a polyisobutene or a polystyrene. The solid particles comprise elements smaller than 0.063 mm, with at least 30% by weight of these elements smaller than 0.063 mm being derived from limestone.

Description

Title of the invention: COMPACT HYDROCARBON COATINGS HAVING IMPROVED WORKABILITY AND COMPACTIBILITY PROPERTIES FIELD OF THE INVENTION

[0001] The present invention belongs to the field of hot or reduced temperature hydrocarbon mixes. It relates to compacted hydrocarbon mixes having improved compactibility and workability properties, which are suitable for use in roadways, in particular within a wearing course or a base course. The present invention also relates to the process for preparing such compacted hydrocarbon mixes. TECHNOLOGICAL BACKGROUND

[0002] Compacted hydrocarbon mixes represent the main component of roadways in France and throughout the world. They are generally present in both the base layers and the wearing courses. The most widely used technique in the manufacture of roadways is that of "hot" hydrocarbon mixes in which the constituents (solid particles and binders) are heated to temperatures typically ranging from 130°C to 190°C. These high temperatures are necessary to reduce the viscosity of the binder and to give sufficient workability and compactibility to the mix. A satisfactory coating is thus obtained and the mechanical properties of the mixes after implementation and cooling are in accordance with the expectations of those skilled in the art.

[0003] The workability and compactibility properties of hydrocarbon mixes are therefore highly dependent on their manufacturing and implementation temperatures. However, temperature is a parameter that is sometimes difficult to control on site due to weather conditions and transport and storage times, which can have a significant influence on the cooling speed of the mixes. In addition, the high temperatures used in hot mixes represent significant and costly energy consumption.

[0004] In the current context of reducing energy consumption, and with the aim of being less dependent on weather conditions, professionals in the road sector are seeking to be able to work over wider ranges of manufacturing and implementation temperatures, particularly at lower temperatures, without the mechanical properties of the coatings being affected. In particular, there is a need to improve the workability and compactibility properties of coatings at lower temperatures than the temperatures normally tional, while maintaining satisfactory mechanical properties, for example rutting resistance and fatigue resistance. Summary of the invention

[0005] The subject of the present invention is a compacted hydrocarbon coating, comprising a hydrocarbon binder and solid particles, characterized in that: a. the hydrocarbon coating further comprises from 0.1 to 5% by weight, relative to the weight of the hydrocarbon binder, of a thermoplastic additive chosen from: - a thermoplastic polymer having at least one carboxylic acid end, the polymer being a polyester, a polyamide, a poly(ester-amide), a polyether functionalized at the chain end by a carboxylic acid function or a polydiene functionalized at the chain end by a carboxylic acid function; or - a thermoplastic polymer functionalized by at least one cyclic anhydride function, the polymer being a polyisobutene or a polystyrene; b. the solid particles comprise elements of a size less than 0.063 mm, at least 30% by weight of the elements of a size less than 0.063 mm being derived from calcareous rocks.

[0006] The present invention also relates to the use of a thermoplastic additive as defined above and below to improve the compactibility of hydrocarbon coatings intended to be compacted, the hydrocarbon coatings comprising a hydrocarbon binder and solid particles, the solid particles comprising elements of a size less than 0.063 mm, at least 30% by weight of these elements being derived from limestone rocks.

[0007] The present invention also relates to the use of a thermoplastic additive as defined above and below to improve targeted segregation during the preparation of a compacted PMA-type hydrocarbon coating.

[0008] The present invention also relates to the use of a compacted hydrocarbon coating as described above for the manufacture of road surfacing, urban development or waterproofing layers for structures and buildings.

[0009] The present invention also relates to a method for preparing a compacted hydrocarbon coating of the invention, comprising the following steps: a) preparation of a hydrocarbon coating by mixing solid particles, a hydrocarbon binder and a thermoplastic additive as described above and below, the thermoplastic additive content ranging from 0.1 to 5% by weight, relative to the weight of the hydrocarbon binder, solid particles comprising elements having a size less than 0.063 mm, at least 30% by weight of these elements being derived from limestone rocks; b) spreading the hydrocarbon coating obtained in step a); c) compaction of the hydrocarbon coating.

[0010] Other aspects of the invention are as described in the claims or below. DETAILED DESCRIPTION

[0011] The inventors of the present invention have, surprisingly, developed a formulation of coatings making it possible to meet the aforementioned needs. Thus, the present invention relates to a compacted hydrocarbon coating comprising a hydrocarbon binder and solid particles, characterized in that: a. the hydrocarbon coating further comprises from 0.1 to 5% by weight, relative to the weight of the hydrocarbon binder, of a thermoplastic additive chosen from: - a thermoplastic polymer having at least one carboxylic acid end, the polymer being a polyester, a polyamide, a poly(ester-amide), a polyether functionalized at the chain end by a carboxylic acid function or a polydiene functionalized at the chain end by a carboxylic acid function; or - a thermoplastic polymer functionalized by at least one cyclic anhydride function, the polymer being a polyisobutene or a polystyrene; b. the solid particles comprise elements of a size less than 0.063 mm, at least 30% by weight of the elements of a size less than 0.063 mm being derived from calcareous rocks.

[0012] The inventors of the present invention have discovered that the use of the thermoplastic additive as described in detail below makes it possible to influence both the compactibility and workability properties of hydrocarbon coatings.

[0013] The workability and compactibility of asphalts represent two very distinct properties from one another.

[0014] The compactibility of asphalt mixes corresponds to their ability to be compacted, i.e. to reach a reference density, after spreading on the roadway. Good compactibility of asphalt mixes makes it possible to obtain satisfactory mechanical properties of the resulting roadway. In the case of wearing courses, this translates into good traffic resistance, sufficient rigidity, high adhesion strength (water resistance) and good feathering resistance properties. In the case of base layers, this translates into good traffic resistance, high rigidity, good water resistance and significant fatigue resistance. The compactibility of asphalt mixes is measured during the laboratory formulation study or during industrial production, by means of the compactibility measurement test of asphalt mixes subjected to the gyratory shear press.

[0015] The workability of the coatings constitutes a sought-after property for good quality of implementation, in particular to limit the arduousness of manual work. The ma The ability to spread the asphalt more quickly and easily on the road surface. It can be measured in the laboratory or on site, in particular using the method described in the experimental section.

[0016] The term “hydrocarbon coated material” designates a product comprising solid particles coated with a hydrocarbon binder. The solid particles and the hydrocarbon binder are as defined below.

[0017] The term "compacted hydrocarbon mix" refers to a hydrocarbon mix that has undergone a compaction step. Indeed, after their manufacture, during implementation, the mixes are compacted after spreading. Compacted hydrocarbon mixes are therefore distinguished in particular from poured asphalts by this compaction step. By definition, poured asphalts do not contain voids and do not require compaction energy during their implementation. Poured asphalts are described in standard NF-EN 13108-6.

[0018] The compacted hydrocarbon coatings of the invention have mechanical properties in accordance with those expected for wearing courses and base layers, in particular those described in standard NF EN 13108. Hydrocarbon binder

[0019] A “binder” within the meaning of the present invention is a material whose thermoplastic properties enable it to harden upon cooling and to bind solid particles together.

[0020] The term "hydrocarbon binder" designates any binder of fossil or plant origin or of synthetic origin usable for the production of so-called "bituminous" products. The hydrocarbon binder can be a bitumen, and be pure or modified, in particular by the addition of polymer(s), fibers, pigments.

[0021] The binder may be a soft to hard binder, advantageously of a grade ranging from 10 / 20 to 160 / 220.

[0022] The bitumen-modifying polymers referred to herein may be chosen from natural or synthetic polymers. These include, for example, polymers from the elastomer family, synthetic or natural, and by way of example and without limitation: - of random, multi-block or star copolymers of styrene and butadiene or isoprene in all proportions (in particular block copolymers of styrene-butadiene-styrene (SBS), styrene-butadiene (SB, SBR for styrene-butadiene rubber), styrene-isoprene-styrene (SIS)) or copolymers of the same chemical family (isoprene, natural rubber, etc.), possibly crosslinked in situ, - of copolymers of vinyl acetate and ethylene in all proportions, - of copolymers of ethylene and esters of acrylic acid, methacrylic acid or maleic anhydride, copolymers and terpolymers of ethylene and methacrylate glycidyl and polyolefins.

[0023] The bitumen-modifying polymers may be chosen from recovered polymers, for example "rubber crumbs" or other compositions based on rubber reduced to pieces or powder, for example obtained from used tires or other polymer-based waste (cables, packaging, agricultural, etc.) or any other polymer commonly used for modifying bitumens such as those cited in the Technical Guide written by the International Road Association (AIPCR) and published by the Laboratoire Central des Ponts et Chaussées "Use of Modified Bituminous Binders, Special Bitumens and Bitumens with Additives in Road Pavements" (Paris, LCPC, 1999), as well as any mixture in any proportion of these polymers.

[0024] The binder advantageously represents from 3% to 12% by weight of the weight of the compacted hydrocarbon mix, even more advantageously from 3% to 10% by weight of the weight of the compacted hydrocarbon mix. The binder content within the compacted hydrocarbon mix may in particular depend on the type of mix and the use made of it (base course or wearing course). A person skilled in the art will be able to adjust the binder content according to these different parameters. Solid particles

[0025] The term "solid particles" designates all solid particles which can be used for the production of road and development products, in particular which can be used for the production of compacted hydrocarbon coatings.

[0026] Examples of solid particles include mineral solid particles such as natural mineral aggregates (gravel, sand, fines), for example from quarries or gravel pits, products from the recycling of coatings such as asphalt aggregates, for example resulting from the recycling of materials recovered during the repair of coatings or from surplus from asphalt plants, manufacturing waste, aggregates from the recycling of road materials including concrete, slags, in particular slag, schists, in particular bauxite or corundum, rubber crumb, for example from the recycling of tires, artificial aggregates of any origin and aggregates from, for example, bottom ash from household waste incineration (MIOM), as well as their mixtures in all proportions.

[0027] Solid particles, in particular mineral solid particles, for example natural mineral aggregates, typically comprise: - elements smaller than 0.063 mm (which correspond to the fillers (also called filler fines) and / or the fine fraction of the sand, together referred to as “fines”), - elements with a size ranging from 0.063 mm to 2 mm (which correspond to the coarse fraction of the sand and / or are provided by the gravel), and - elements having a size ranging from 2 mm to 6 mm and elements having a size greater than 6 mm, for example up to 40 mm (which are provided by / correspond to the gravel or coarse aggregates).

[0028] In other words, the fines consist of elements passing through the 0.063 mm sieve, the elements having a size ranging from 0.063 mm to 2 mm consist of elements retained through the 0.063 mm sieve but passing through the 2 mm sieve and the elements having a size ranging from 2 mm to 6 mm and the elements having a size greater than 6 mm consist of elements retained through the 2 mm sieve.

[0029] The size (or dimension or diameter) of solid particles, in particular mineral solid particles, for example mineral aggregates, is measured by the tests described in standard NF EN 933-2 (07 / 2020).

[0030] “Mineral solid particles” are also referred to as “0 / D mineral fraction”. This 0 / D mineral fraction can be separated into two particle sizes: the 0 / d mineral fraction and the d / D mineral fraction. The finest elements (the 0 / d mineral fraction) are those in the range between 0 and a maximum diameter that can be set between 2 and 6 mm. The other elements (minimum diameter greater than 2, 3, 4, 5 or 6 mm; and approximately up to 40 mm) constitute the d / D mineral fraction.

[0031] The particle size distribution and the nature of the solid particles within the compacted hydrocarbon coatings of the invention may in particular depend on the type of coating and the use made of it. Those skilled in the art will be able to adjust the particle size distribution and the nature of the solid particles according to these different parameters.

[0032] In the context of the present invention, at least 30% by weight of the elements having a size less than 0.063 mm are elements derived from limestone rocks. The elements having a size less than 0.063 mm derived from limestone rocks may represent up to 100% by weight of the elements having a size less than 0.063 mm. Thus, in certain embodiments, the elements having a size less than 0.063 mm comprise from 30 to 100% by weight or from 50 to 100% by weight or from 60 to 90% by weight of elements derived from limestone rocks. Thus, the fillers are generally derived from limestone rocks. The sand, and therefore the fine fraction of the sand, may or may not be derived from limestone rocks.

[0033] Limestone rocks are composed mainly of calcium carbonate, that is to say they comprise at least 50% by weight of calcium carbonate. The calcium carbonate will interact with the thermoplastic additive.

[0034] Elements larger than 2 mm (e.g. gravel) may or may not be derived from limestone rocks. When compacted asphalt is used as a wearing course, the gravel is generally not derived from limestone rocks. (they generally contain little or no calcium carbonate). Thermoplastic additive

[0035] The compacted hydrocarbon mix of the present invention comprises a thermoplastic additive which makes it possible to improve both the compactibility and the workability of the hydrocarbon mixes. In other words, this thermoplastic additive makes it possible to obtain compactibility and workability comparable to those obtained with hot mixes (i.e. at temperatures of the order of 180°C to 200°C) by using lower manufacturing and implementation temperatures, typically of the order of 80°C to 170°C, in particular of 110°C to 170°C or of 120°C to 160°C. However, the compacted hydrocarbon mix of the present invention comprising a thermoplastic additive as described below can also be obtained at higher temperatures, for example up to 190-200°C.

[0036] The manufacturing temperature of a hydrocarbon coating refers to the temperature of the coating during its preparation in a coating plant, typically at the mixer outlet.

[0037] The implementation temperature of a hydrocarbon coating designates the temperature of the coating during its application, more particularly the temperature of the coating in the screw of the finisher before the smoothing table or the temperature of the coating after the smoothing table before compaction.

[0038] This thermoplastic additive is compatible with the hydrocarbon binder, in other words the thermoplastic additive is stable, soluble and inert in the hydrocarbon binder. The affinity of the thermoplastic additive with the hydrocarbon binder can be verified using the storage stability test described in standard NF EN 13399 (August 2000). In addition, in the presence of the thermoplastic additive, the binder content of the asphalt mix can be reduced, without altering the compactibility and workability of the asphalt mix.

[0039] The compacted hydrocarbon coating according to the invention comprises from 0.1 to 5% or from 0.5 to 2% or from 0.5 to 1.5% by weight, relative to the weight of the hydrocarbon binder, of the thermoplastic additive.

[0040] This thermoplastic additive comprises at least one carboxylic acid function (-COOH) or cyclic anhydride (easily hydrolyzable and releasing carboxylic acid functions) thus allowing a chemical interaction with calcium carbonate.

[0041] The carboxylic acid function(s) may all be totally acidic, or may be totally or partially neutralized by a neutralizing agent. Examples of neutralizing agents that may be mentioned are sodium hydroxides, potassium hydroxides, calcium hydroxides and / or oxides, magnesium hydroxides and / or oxides, ammonia, or mixtures thereof.

[0042] The thermoplastic additive useful in the context of the invention is a polymer, that is, it comprises several repeating units. By "several" is meant "at least two", advantageously "at least three". This polymer comprises at least one terminal carboxylic acid function. When the polymer comprises more than one carboxylic acid function, typically at least 20 carbon atoms separate these carboxylic acid functions.

[0043] The polymer is advantageously linear.

[0044] The thermoplastic additive advantageously has a molecular weight by weight of at least 500 g / mol, more advantageously from 500 g / mol to 200,000 g / mol.

[0045] The thermoplastic additive advantageously has an acid number lower than 100 mgKOH / g, more preferably less than 50 mgKOH / g. The acid number is the mass of potassium hydroxide (expressed in mg) required to neutralize the free acid functions contained in one gram of thermoplastic additive.

[0046] The thermoplastic additive is polyester, a polyamide, a poly(ester-amide), a polyether functionalized at the end of the chain by a carboxylic acid function or a polydiene functionalized at the end of the chain by a carboxylic acid function.

[0047] The thermoplastic additive may also be a polymer functionalized by at least one cyclic anhydride function (e.g. succinic anhydride or maleic anhydride), the polymer being a polyisobutene or a polystyrene (e.g. polyisobutene succinic anhydride (PIBSA) or styrene-maleic anhydride (SMA)). The polymer may be functionalized in the middle of the chain, at the end of the chain or in the middle of the chain and at the end of the chain.

[0048] In some embodiments, the thermoplastic additive is a polyester, a polyamide or a poly(ester-amide).

[0049] In certain embodiments, the thermoplastic additive useful in the context of the invention is a thermoplastic polyester obtained by polymerization of at least one hydroxy acid of formula (I): HO-C(O)-R-CR'(OH)-R” (I) in which: - R is an aliphatic hydrocarbon chain, C8-C20, saturated or unsaturated, optionally branched, optionally comprising one or more oxygen atoms, comprising a linear main chain of at least 8 carbon atoms, - R', R” each represent, independently of one another, H or an aliphatic hydrocarbon chain in Cl-CIO.

[0050] Advantageously, R meets one or more of the following characteristics, advantageously all of the following characteristics: - R is a linear hydrocarbon chain; - R is a hydrocarbon chain which can be saturated or unsaturated. Unsaturation, when present, is preferably a C=C double bond or a C=C triple bond, more preferably a double C=C bond. In one embodiment, R is a hydrocarbon chain that comprises 0 to 3 C=C double bonds, preferably 0 to 2 C=C double bonds, more preferably 1 C=C double bond; - R is a C8-C15 hydrocarbon chain, more advantageously C10-C15, even more advantageously C10.

[0051] In addition, R may comprise one or more oxygen atoms either interrupting the chain (ether functions) or pendant in the form of C1-C6 hydroxyl or ether functions. Advantageously, R does not comprise oxygen atoms.

[0052] R' and R” may represent, independently of one another, a linear or branched, saturated or unsaturated C1-C10 aliphatic hydrocarbon chain.

[0053] Advantageously, R' represents H or a saturated, linear, aliphatic hydrocarbon chain, more advantageously C1-C4. More advantageously, R' represents H.

[0054] Advantageously, R” represents a linear, saturated or unsaturated, aliphatic hydrocarbon chain. The unsaturation, when present, is advantageously a C=C double bond or a C=C triple bond, more advantageously a C=C double bond. In one embodiment, R” is a saturated hydrocarbon chain. Advantageously, R” is a C4-C8 chain, in particular a C5 chain. R” may comprise one or more oxygen atoms either interrupting the chain (ether functions) or pendant in the form of C1-C6 hydroxyl or ether functions. Advantageously, R” does not comprise oxygen atoms.

[0055] A hydroxy acid of formula (I) can be homopolymerized or several hydroxy acids of formula (I) can be copolymerized.

[0056] Furthermore, the polymerization reaction can be carried out in the presence of non-hydroxylated fatty acids, in particular saturated or unsaturated olefinic fatty acids comprising from 8 to 30 carbon atoms, optionally substituted by a C1-C4 alkyl radical. Examples that may be mentioned are oleic acid, palmitic acid, stearic acid, linoleic acid, 2-ethylhexanoic acid, etc.

[0057] In certain embodiments, the polyester may be obtained by copolymerization of at least one dicarboxylic acid and at least one diol. It is understood that one or more dicarboxylic acids may be copolymerized with one or more diols.

[0058] Advantageously, the dicarboxylic acid is a C3-C20 diacid, more advantageously a C4-C16 diacid, even more advantageously a C4-C12 diacid. The diacid is advantageously aliphatic, advantageously linear or branched. The diacid may comprise one or more unsaturations, in particular olefinic.

[0059] The dicarboxylic acid is advantageously sebacic acid, azelaic acid, adipic acid, glutaric acid, succinic acid, maleic acid, itaconic, and their mixtures.

[0060] Advantageously, the diol is a diol comprising at least three carbon atoms. The diol may in particular be an alkyl diol, an alkenyl diol or an alkynyl diol, advantageously C3-C20, or a hydroxytelechelic polymer. Advantageously, the diol is an unsaturated C3-C20 alkyl diol, such as, for example, dodecanediol, decanediol, hexanediol, butanediol, or propanediol. Advantageously, the diol is a hydroxytelechelic polymer, the polymer being chosen from polydienes or polyethers, such as, for example, hydroxytelechelic polybutadienes, hydroxytelechelic polytetrahydrofurans, or hydroxytelechelic polypropylene glycols. A mixture of such diols may also be used.Advantageously, the diol is chosen from dodecanediol, decanediol, hexane diol, butanediol, propanediol, hydroxytelechelic polybutadienes, hydroxytelechelic polytetrahydrofurans, hydroxytelechelic polypropylene glycols and mixtures thereof.

[0061] The polyester may also be obtained by ring-opening polymerization of a lactone and be terminal carboxylic acid functionalized by condensation with a polyacid, for example a diacid, in excess, or by ring-opening of a lactone, a lactide or a cyclic anhydride. The cyclic anhydride may comprise from 4 to 10 cyclic carbon atoms.

[0062] The polymer may also be a polyamide. Such a polyamide may be obtained by polymerization of at least one dicarboxylic acid and at least one diamine. It is understood that one or more dicarboxylic acids may be copolymerized with one or more amines.

[0063] Advantageously, the dicarboxylic acid is as defined previously for the polyester.

[0064] Advantageously, the diamine is an alkyl diamine or an alkenyl diamine or an alkynyl diamine, more advantageously C4-C20. By way of example, mention may in particular be made of tetramethylene diamine, hexamethylene diamine, or deca-nediamine.

[0065] Polyamides may also be prepared by ring-opening polymerization of lactams, in particular lactams comprising at least 5 carbon atoms.

[0066] Polyester-amides can be obtained by copolymerization of at least one dicarboxylic acid, at least one diol and at least one amine. The dicarboxylic acid, the diol and the diamine are advantageously as defined above.

[0067] Polyester-amides can be obtained by copolymerization of at least one dicarboxylic acid, at least one diol and at least one lactam. The monomers are as described above.

[0068] In some embodiments, the thermoplastic polymer is a polyether functionalized at the carboxylic acid chain end or a polydiene functionalized at the carboxylic acid chain end. Thus, the carboxylic acid function is introduced by modification of a polymer.

[0069] The polydiene is advantageously polybutadiene or polyisoprene as well as isoprene-butadiene copolymers.

[0070] The polyether is advantageously polytetrahydrofuran or polypropylene glycol.

[0071] The polymer can be functionalized with carboxylic acid in the terminal position by any method known to those skilled in the art.

[0072] In particular, the polymer can be obtained by condensation of a mono or dihydroxytelechelic polyether and a polyacid, for example a diacid, in excess, or by ring opening of a lactone, a lactide or a cyclic anhydride with a mono or dihydroxytelechelic polyether.

[0073] In particular, the polymer may be obtained by condensation of a mono or dihydroxytelechelic polydiene and an excess diacid, or by ring opening of a lactone, a lactide or a cyclic anhydride with a mono or dihydroxytelechelic polydiene.

[0074] The diacid may be a dicarboxylic acid as defined above.

[0075] The cyclic anhydride may comprise from 4 to 10 cyclic carbon atoms.

[0076] Advantageously, the thermoplastic additive is poly(ricinoleic acid) or poly(12-hydroxy stearic acid).

[0077] The thermoplastic additive interacts with the calcareous solid particles (i.e. the solid particles from calcareous rocks), in particular with calcium carbonate. It improves the workability, but also the compactibility of the hydrocarbon coatings intended to be compacted. Thus, the invention also relates to the use of a thermoplastic additive as described here, in particular a thermoplastic polyester obtained by polymerization of at least one hydroxy acid of formula (I): HO-C(O)-R-CR'(OH)-R” (I) where R is an aliphatic hydrocarbon chain, C8-C20, saturated or unsaturated, optionally branched, optionally comprising one or more oxygen atoms, comprising a linear main chain of at least 8 carbon atoms, R', R” each represent, independently of one another, H or an aliphatic hydrocarbon chain, Cl-CIO, to improve the compactibility of hydrocarbon coatings intended to be compacted. Handling additives

[0078] The compacted hydrocarbon coating optionally comprises one or more workability additives, in addition to the thermoplastic additive described above.

[0079] The workability additives make it possible to improve the workability of compositions intended for the preparation of road and development products. The workability additives may be as described in EP3612597A1.

[0080] Compacted hydrocarbon coatings and their uses

[0081] A compacted hydrocarbon coating of the present invention may be a usual / conventional coating or a so-called PMA (Porous Mastic Asphalt) coating. These coatings are distinguished from each other in particular by the particle size distribution of the solid particles. Conventional coatings

[0082] In the context of the invention, usual or conventional coatings designate coatings according to standards NF EN 13108-1, NF EN 13108-2, NF EN 13108-4, NF EN 13108-5 and NF EN 13108-7. They are typically used for the preparation of bituminous products useful in base layers, for example a Bituminous Gravel (NF EN 13108-1 of February 2007) or a High Modulus Asphalt, or in wearing courses, for example BBSG (Semi-Grained Bituminous Concrete), BBM (Thin Bituminous Concrete), BBS (Flexible Bituminous Concrete), SMA (Stone Mastic Asphalt), Hot Rolled Asphalt (13108-4), BBTM (Very Thin Bituminous Concrete), BBDr (Pervious Bituminous Concrete) or BBME (High Modulus Bituminous Concrete).

[0083] The usual coatings are typically made up of sand, gravel and limestone fillers (from limestone rocks).

[0084] Sand, which may or may not be calcareous, typically consists of a fine fraction and a coarse fraction. The fine fraction of sand consists of elements smaller than 0.063 mm and the coarse fraction consists of elements ranging in size from 0.063 mm to 2 mm. In other words, sand consists of a 0 / 2 mineral fraction.

[0085] The gravel consists of elements having a size D greater than 2 mm and typically less than or equal to 6 mm.

[0086] The limestone fillers consist of elements smaller than 0.063 mm.

[0087] The total fines (elements smaller than 0.063 mm) are therefore made up of fines from the sand and limestone fillers. Typically, in conventional asphalt mixes, limestone fillers represent 0 to 5% by weight relative to the total weight of solid particles.

[0088] The usual coatings of the invention, such as Grave Bitume, typically have the following particle size distribution: - elements smaller than 0.063 mm: from 5% to less than 15%, preferably from 5% to 12%, in particular from 6% to 10%, by weight relative to the total weight of the solid particles; - elements of size ranging from 0.063 mm to 2 mm: from 20% to 35%, in particular from 20% to 32%, by weight relative to the total weight of solid particles, - elements larger than 2 mm: from 50% to 80%, in particular from 55% to 75%, more particularly from 58% to 74% by weight relative to the total weight of solid particles.

[0089] Elements larger than 2 mm, in other words gravel or coarse aggregates, in standard asphalt mixes, advantageously have a maximum diameter D of 40 mm, preferably 14 mm in the case of Bitumen Gravel. They can be mineral and derived from calcareous or siliceous rocks. Generally, the gravel used for the preparation of base layers (e.g. Bitumen Gravel) is calcareous.

[0090] The usual coatings of the invention have a hydrocarbon binder content typically ranging from 3% to 10% by weight relative to the total weight of the usual coatings.

[0091] The usual coatings of the invention typically have a percentage of voids ranging from 1% to 30%, in particular from 1% to 15% and more particularly from 1% to 11% in the case of a Grave Bitumen relative to the total weight of the usual coatings.

[0092] The usual coatings according to the invention are distinguished in particular from PMA coatings by the proportion of elements having a size ranging from 0.063 mm to 2 mm, this proportion ranging from 20% to 35% by weight, when it is less than or equal to 15% by weight in the PMA coatings relative to the total weight of the solid particles.

[0093] In conventional coatings, the thermoplastic additive makes it possible in particular to improve the compactibility and workability of the coatings at lower manufacturing and implementation temperatures than those conventionally applied, for example ranging from 80°C to 170°C, preferably from 110 to 170°C or from 120°C to 160°C. PMA coatings

[0094] By definition, PMA coatings have, after spreading / application, a heterogeneous structure which comprises an upper layer (surface layer) and a lower layer. The upper layer is said to be porous and the lower layer is said to be dense and compact.

[0095] The upper layer (surface layer) consists of a porous granular skeleton made up of coarse aggregates (having a size D greater than 2 mm, and preferably less than or equal to 5 mm).

[0096] The top layer of PMAs includes little or no asphalt mastic.

[0097] The term "asphalt mastic" refers to a mixture of hydrocarbon binder, in particular bitumen, elements of a size less than 0.063 mm, and possibly elements of a size ranging from 0.063 mm to 2 mm. In other words, asphalt mastic generally includes added fillers and sand (fine and coarse sand).

[0098] Typically, the top layer comprises less than 10% by volume of mastic, preferably less than 5% by volume. It thus forms a porous texture.

[0099] The top layer generally has a thickness ranging from 0.3 cm to 1 cm, in particular a thickness of about 0.5 cm. The top layer generally represents from 10% to 25% of the total thickness of the PMA.

[0100] The upper layer comprises a volume of voids typically ranging from 15% to 30% relative to the volume of the PMA mix in its entirety.

[0101] The lower layer consists of the same granular skeleton as the upper layer and an asphalt mastic filling the interstices of the granular skeleton. The lower layer of the PMA has a thickness generally ranging from 2.5 cm to 5 cm.

[0102] The lower layer of the PMA generally represents from 75 to 90% of the total thickness of the PMA. This lower layer comprises a volume of voids typically ranging from 0 to 5% relative to the volume of the layer.

[0103] PMA mixes are typically prepared from sand, gravel and limestone fillers as defined above.

[0104] Sand, which may or may not be calcareous, typically consists of a fine fraction and a coarse fraction.

[0105] The total fines consist of limestone fillers and the fine fraction of sand. Typically, in PMA mixes, the fines from the sand represent from 0 to 20% by weight relative to the total weight of the solid particles.

[0106] The PMA coatings according to the invention typically have the following particle size distribution: - elements smaller than 0.063 mm: from 15% to less than 25%, in particular from 15% to 20%, by weight relative to the total weight of solid particles; - elements of size ranging from 0.063 mm to 2 mm: from 5% to 15%, in particular from 6% to 15%, by weight relative to the total weight of solid particles, - elements larger than 2 mm: from 60% to 80%, in particular from 65% to 80% by weight relative to the total weight of solid particles.

[0107] The PMA coatings of the invention have a binder content typically ranging from 6% to 8.5% by weight relative to the total weight of the PMA coatings.

[0108] PMA coatings typically comprise from 0.1 to 2% by weight, advantageously from 0.2 to 1.5% by weight, more advantageously 0.6 to 1.2% by weight, relative to the weight of the hydrocarbon binder, of the thermoplastic additive.

[0109] A PMA mix is ​​obtained by hot pouring of a mixture comprising a hydrocarbon binder and solid particles as defined above. During the preparation of PMAs, the asphalt mastic infiltrates by gravity into the porosities of the granular skeleton leaving a porous texture on the surface and thus forming a dense and compact lower layer with few voids.

[0110] In PMA mixes, the thermoplastic additive makes it possible in particular to improve the compactibility and workability of the mixes at lower manufacturing and implementation temperatures than those conventionally applied, for example ranging from 80°C to 170°C, preferably from 110 to 170°C or from 120 to 160°C.

[0111] The inventors of the present invention have also discovered that the thermoplastic additive promotes targeted segregation during the preparation of PMAs. As previously indicated, during the preparation of PMAs, the asphalt mastic infiltrates by gravity into the porosities of the granular skeleton, leaving a porous texture on the surface and forming a dense and compact lower layer with few voids. The infiltration of the asphalt mastic within the granular skeleton by gravity so as to create a porous upper layer and a dense lower layer is called "targeted segregation". It is essential that the segregation between the asphalt mastic and the aggregates of the granular skeleton be done efficiently and quickly during the manufacture of PMAs to obtain the desired properties of the PMAs.The asphalt mastic must therefore have an adequate viscosity to fill the granular skeleton and allow the formation of a porous layer on the surface. To this end, prior art techniques use high processing temperatures, generally between 160°C and 190°C, to obtain the adequate viscosity of the asphalt mastic and allow this targeted segregation.

[0112] The inventors of the present invention have therefore surprisingly discovered that the use of the thermoplastic additive, in addition to improving the workability and compactibility of the mixes, makes it possible to act on the lubrication of the asphalt mastic and to promote targeted segregation during the preparation of the PMA mixes at lower implementation temperatures than those conventionally applied, for example ranging from 80°C to 170°C, preferably from 110°C to 170°C or from 120 to 160°C. The thermoplastic additive acts as an interface agent between the asphalt mastic and the granular skeleton of the PMA. Thus, elements smaller than 0.063 mm and elements ranging from 0.063 mm to 2 mm contained in the asphalt mastic will penetrate more easily the granular skeleton, thus forming the dense and compact lower layer of the PMA coating and promoting the formation of the porous layer on the surface.

[0113] The invention also relates to the use of a thermoplastic additive as described above, to improve the targeted segregation between the asphalt mastic and the granular skeleton within a PMA coating. Process for preparing compacted asphalt

[0114] The preparation of the compacted hydrocarbon coatings according to the invention comprises the next steps: a) preparation of hydrocarbon coatings by mixing solid particles, a hydrocarbon binder and a thermoplastic additive as described above, the content of thermoplastic additive ranging from 0.1 to 5% by weight, relative to the weight of the hydrocarbon binder, solid particles comprising elements having a size less than 0.063 mm, at least 30% by weight of these elements being derived from limestone rocks; the preparation being typically carried out at a manufacturing temperature ranging from 80°C to 170°C, preferably from 110°C to 170°C; b) spreading the coatings obtained in step a), typically at an implementation temperature ranging from 110°C to 170°C; c) compaction of the coatings.

[0115] In some embodiments, steps a) and b) are carried out at a temperature ranging from 110°C to 170°C. Steps a) and b) may be carried out at higher temperatures than those indicated above, for example they may be carried out at temperatures up to 190°C.

[0116] The spreading of the coatings is carried out, for example, with a finisher or a grader. The compacted hydrocarbon coatings according to the invention allow traffic to be put back into service in less than 72 hours, more advantageously within 24 hours after spreading.

[0117] Compaction is carried out so as to obtain the desired percentage of voids in the asphalt layer. The percentages of voids according to the type of asphalt are described above.

[0118] The compacted hydrocarbon coatings according to the invention can be used in all usual coating applications, in particular for the manufacture of road surfaces, urban developments (e.g. pavements) or waterproofing layers for structures and buildings.

[0119] Compacted hydrocarbon mixes are particularly useful for preparing a base layer. In this case, the compacted hydrocarbon mixes are typically standard mixes as described above.

[0120] Compacted hydrocarbon mixes are also useful for preparing a wearing course. In this case, the compacted mixes are typically conventional mixes, SMA mixes or more preferably PMA mixes as described above. PMA mixes are particularly preferred for obtaining a coating with good acoustic properties, in other words low noise. Indeed, due to their composition, PMA mixes make it possible to reduce noise pollution from road traffic. They also make it possible to promote rainwater runoff and improve the adhesion of tires to the road surface. Integrated as a wearing course in road surfaces, PMA mixes protect the lower parts of the coatings thanks to the waterproofing provided by the lower layer of PMA asphalt mix comprising asphalt mastic and granular skeleton. PMA asphalt mixes thus increase the lifespan of road surfaces and therefore reduce maintenance costs.

[0121] The present invention thus relates to a base or wearing course comprising a compacted hydrocarbon coating as described here.

[0122] The present invention also relates to a road surface comprising at least one layer of a compacted hydrocarbon coating as described herein. FIGURES

[0123] [Fig-1] Figure IA (top) represents a diagram of the operation of the mani- Nynas bilimeter in operation, in which a lever arm exerts a thrust shear force on a layer of asphalt placed in the bilimeter mold. Figure 1B (bottom) is a photograph of a Nynas device.

[0124] [Fig.2] [Fig.2] represents the evolution of the compaction energy required (expressed in number of gyrations) to achieve a target compactness according to the temperature (in °C), obtained by a PCG test, for a BBSG 0 / 10 mix with 35 / 50 bitumen according to the invention and a BBSG 0 / 10 mix with 35 / 50 reference bitumen, as described in example 1.

[0125] [Fig.3] [Fig.3] represents the cohesion force F (in N) according to the temperature (°C), measured using a Nynas handling meter, for a BBSG 0 / 10 mix with 35 / 50 bitumen according to the invention and a BBSG 0 / 10 mix with 35 / 50 reference bitumen, as described in example 1.

[0126] [Fig.4] [Fig.4] represents the evolution of the compaction energy required (expressed in number of gyrations) to achieve a target compactness according to the temperature (in °C), obtained by a PCG test, for a GB 0 / 14 mix with 35 / 50 bitumen according to the invention and a GB 0 / 14 mix with 35 / 50 reference bitumen, as described in example 2.

[0127] [Fig.5] [Fig.5] represents the cohesion force F (in N) according to the temperature (°C), measured using a Nynas handling meter, for a GB / 014 mix with 35 / 50 bitumen according to the invention and a GB 0 / 14 mix with 35 / 50 reference bitumen, as described in example 2.

[0128] [Fig.6] [Fig.6] represents the arithmetic mean height Sa (surface) of a PMA mix according to the invention and of a reference PMA mix as described in example 3, as a function of the temperature. EXAMPLES

[0129] • METHODS

[0130] Maneuverability measurement using a NYNAS maneuverability meter

[0131] The Nynas manibilimeter is a commonly used instrument for measuring ma Workability of asphalt mixes. This measure determines how easily the asphalt mix can be placed and compacted on the road. Workability is defined as a maximum cohesive strength F expressed in N. It depends on the temperature of the asphalt layer. The lower the temperature, the less workable the asphalt layer is, and the higher the cohesive strength.

[0132] The tests carried out aim to determine at what temperature the workability threshold of 300N (limit force beyond which the asphalt layer is no longer considered workable, see Faucon-Dumont et al., RGRA, n°928, June 2015) is reached, depending on the asphalt used. The tests are carried out with asphalt having a compactness, i.e. a constant density, of 0.75.

[0133] The Nynas handling meter contains a mold into which a layer of asphalt is poured at the processing temperature. A photo of a Nynas device is shown in Figure 1B. A lever arm exerts a shear force on the layer of asphalt. The force exerted by the lever arm is measured using a force sensor. The handling corresponds to the value of the force exerted by the lever arm during the decohesion of the layer of asphalt. The test is shown schematically in Figure 1A. The operation is repeated as the temperature decreases for the force F as a function of the temperature. Compactibility measurement: PCG test

[0134] This test is carried out using the Gyratory Shear Press (GSP) in accordance with standard NF EN 12697-31. The objective is to determine at what temperature the target level of compactibility is reached depending on the asphalt used.

[0135] The target compactibility level is illustrated by the number of gyrations at the PCG required to achieve the desired percentage of voids. The number of gyrations required depends on the temperature at which the test is carried out. The test is carried out at three different temperatures: 165°C (temperature of a hot mix based on 35 / 50 bitumen according to standard NF EN 12697-35), 120°C and 100°C.

[0136] For each temperature and for each coating, the percentage of voids in the coating layer as a function of the number of gyrations at the PCG is recorded. The logarithmic curve of the percentage of voids as a function of the number of gyrations is plotted and makes it possible to obtain the number of gyrations necessary to reach the percentage of voids at n gyrations according to the normative requirements or product requirements. Example 1: BBSG 0 / 10 35 / 50 rolling coating

[0137] The compositions of a BBSG 0 / 10 coating with 35 / 50 bitumen comprising a thermoplastic additive as previously described (thermoplastic polyester) (BBSG 0 / 10 according to the invention) and of a BBSG 0 / 10 coating with 35 / 50 bitumen without the thermoplastic additive (BBSG 0 / 10 reference) are given in the following table:

[0138] [Tables 1] Constituent BBSG 0 / 10 (reference) BBSG 0 / 10 (invention) Solid particles Elements of size greater than or equal to 2 mm Gravel 6 / 10 40.5% 40.5% Gravel 2 / 6 18.3% 18.3% Elements of size ranging from 0.063 mm to 2 mm Coarse fraction of sand 28.0% 28.0% Elements of size less than 0.063 mm Fines from sand 5.5% 5.5% Limestone filler 2.5% 2.5% Total fines 8.0% 8.0% Bitumen 35 / 50 5.2% 5.2% Thermoplastic additive (% by weight relative to the weight of bitumen) 0 1 Manufacturing temperature 165°C 120°C

[0139] Unless otherwise indicated, the percentages are expressed by weight relative to the total weight of the coating.

[0140] The thermoplastic additive is marketed by the company Oléon under the name Nouracid CE 80, CAS no.: 68604-47-7. Compactibility

[0141] A PCG test as described above is carried out on the two mixes. The number of gyrations required to obtain 8.1% voids within the mix layer (also called compaction energy) is determined at 165°C, 120°C and 100°C for the two mixes. The curve representing the number of gyrations to obtain the target compactness as a function of temperature is shown in [Fig.2]. The temperature difference to achieve the same compaction energy between the two mixes is called compactibility gain.

[0142] It is observed that for the asphalt mix according to the invention, the compaction energy of 60 gyrations necessary to achieve the targeted compactness is obtained at 120°C whereas it is obtained at 165°C for the reference asphalt mix. The thermoplastic additive in the asphalt mixes of the invention therefore makes it possible to obtain a gain in compactibility of 45°C. Handling

[0143] The workability results for the reference mix and the mix according to the invention obtained using the Nynas workability meter according to the method described above (Nynas workability meter) are shown in [Fig.3]. It is observed that the workability threshold of 300N is reached at a temperature 15°C lower for the BBSG0 / 10 according to the invention than for the reference BBSG 0 / 10. The thermoplastic polyester therefore makes it possible to increase the workability of the mixes at lower temperatures. Rutting resistance and rigidity modulus

[0144] The coating according to the invention has rutting resistance results according to standard NF EN 12697-22 and rigidity modulus results according to standard NF EN 12697-26 annex C, which comply with the requirements of a class 3 BBSG.

[0145] The results are presented in the following table:

[0146] [Tables2] BBSG 0 / 10 (reference) BBSG 0 / 10 (invention) Normative specifications Implementation temperature (°C) 165 120 Resistance to rutting % of voids (%) 7.9 7.1 5% - 8% % rut at 10,000 cycles (%) 3.6 3.7 % rut at 30,000 cycles (%) 4.1 4.2 <5% slope 0.1402 0.1215 Rigidity modulus Module 10 °C, 124 ms (MPa) 11662 11077 Module 15 °C, 124 ms (MPa) 6917 6544 Average modulus (MPa) 9289 8810 > 7000 MPa % voids (%) 7.7% 7.0% 5% - 8% Example 2: GB 0 / 14 35 / 50 base coating

[0147] The compositions of a Grave Bitumen (GB) 0 / 14 to bitumen 35 / 50 according to the invention comprising a thermoplastic additive (thermoplastic polyester) and of a GB 0 / 14 to 35 / 50 bitumen without thermoplastic additive are given in the following table:

[0148] [Tables3] Constituent GB 0 / 14 (reference) GB 0 / 14 (invention) Solid particles Elements of size greater than or equal to 2 mm Gravel 10 / 14 limestone 28.0% 28.0% Gravel 6 / 10 limestone 20.1% 20.1% Gravel 2 / 6 limestone 11.4% 11.4% Elements of size ranging from 0.063 mm to 2 mm Coarse limestone fraction of sand 28.1% 28.1% Elements of size less than 0.063 mm Limestone fines from sand 5.9% 5.9% Limestone filler 2.0% 2.0% (Total fines) 7.9% 7.9% Bitumen 35 / 50 4.5% 4.5% Thermoplastic additive (% by weight relative to the weight of the bitumen) 0.6 Manufacturing temperature 165°C 120°C

[0149] Unless otherwise indicated, the percentages are expressed by weight relative to the total weight of the coating.

[0150] The thermoplastic additive is marketed by the company Oléon under the name Nouracid CE 80, CAS no.: 68604-47-7. Compactibility

[0151] A PCG test as described above is carried out on the two mixes. The number of gyrations required to obtain 5.1% voids within the mix layer (also called compaction energy) is determined at 165°C, 120°C and 100°C for the two mixes. The curve representing the number of gyrations to obtain the target compactness as a function of temperature is shown in [Fig.4]. It is observed that for the mix according to the invention, the compaction energy of 100 gyrations required to achieve the target compactness is obtained at 105°C while it is obtained at 165°C for the reference mix. The thermoplastic polyester in the mixes of the invention therefore makes it possible to obtain a gain in compactibility of 60°C. Workability

[0152] The workability results for the reference mix and the mix according to the invention obtained using the Nynas workability meter according to the method described above (Nynas workability meter) are shown in [Fig.5]. It is observed that the workability threshold of 300N is reached at a temperature 15°C lower for the GB 0 / 14 according to the invention than for the reference GB 0 / 14. The thermoplastic polyester therefore makes it possible to increase the workability of the mixes at lower temperatures. Rutting resistance and rigidity modulus

[0153] The coating using innovative technology has mechanical performance results that comply with the requirements of standard NF EN 13108-1.

[0154] The results are presented in the following table:

[0155] [Tables4] GB 0 / 14 (reference) GB 0 / 14 (invention) Normative specifications Implementation temperature (°C) 165 120 Resistance to rutting % voids (%) 5.2 5.0 5% - 8% % rut at 10,000 cycles (%) 5.5 4.4 % rut at 30,000 cycles (%) 6.2 5.0 < 10% slope 0.1943 0.1694 Modulus of rigidity Modulus 10 °C, 124 ms (MPa) 13723 13655 Modulus 15 °C, 124 ms (MPa) 8919 8884 Average modulus (MPa) 11321 11269 > 11000 MPa % voids (%) 5.6 5.1 5% - 8% Resistance to fatigue % of voids (%) 5.6 5.7 5% - 8% e6 in pdef 111 118 >100 Example 3: PMA (Porous Mastic Asphalt) coating:

[0156] The compositions of a PMA 0 / 6 with 35 / 50 bitumen according to the invention comprising a thermoplastic additive (thermoplastic polyester) and of a PMA 0 / 6 with 35 / 50 reference bitumen without thermoplastic additive are given in the following table:

[0157] [Tables5] Constituent PMA 0 / 6 PMA 0 / 6 (invention) (reference) Solid particles Elements of size greater than or equal to 2 mm Gravel 4 / 6 62.5% 62.5% Elements of size ranging from 0.063 mm to 2 mm Coarse fraction of sand 15.0% 15.0% Elements of size less than 0.063 mm Fines from sand 1.7% 1.7% Limestone filler 14.3% 14.3% (Total fines) 16.0% 16.0% Bitumen 35 / 50 6.5% 6.5% Thermoplastic additive (% by weight relative to the weight of bitumen) 0.6 Manufacturing temperature 170°C 150°C

[0158] Unless otherwise indicated, the percentages are expressed by weight relative to the total weight of the coating.

[0159] The thermoplastic additive is marketed by the company Oléon under the name Nouracid CE 80, CAS no.: 68604-47-7.

[0160] These coatings require surface roughness. This characteristic is difficult to obtain due to the temperature variations that can occur on site.

[0161] The arithmetic mean height Sa (surface) represents, in absolute value, the difference in height of each point relative to the mean plane of the surface. This parameter is generally used to evaluate the surface roughness of a coating.

[0162] The results obtained on the roughness measurements as a function of the implementation temperature for the PMA according to the invention and the reference PMA are represented in [Fig.6]. It is observed that when the temperature decreases, the height Sa decreases, in particular below 170°C for the reference PMA mix, reflecting a reduction in the surface roughness. On the other hand, for a PMA mix according to the invention, the surface roughness remains constant depending on the temperature, demonstrating that the targeted segregation also takes place at lower temperatures.

Claims

Claims

1. Compacted hydrocarbon coating comprising a hydrocarbon binder and solid particles, characterized in that: a. the hydrocarbon coating further comprises from 0.1 to 5% by weight, relative to the weight of the hydrocarbon binder, of a thermoplastic additive chosen from: - a thermoplastic polymer having at least one carboxylic acid end, the polymer being a polyester, a polyamide, a poly(ester-amide), a polyether functionalized at the chain end by a carboxylic acid function or a polydiene functionalized at the chain end by a carboxylic acid function; or - a thermoplastic polymer functionalized by at least one cyclic anhydride function, the polymer being a polyisobutene or a polystyrene; b. the solid particles comprise elements of a size less than 0.063 mm, at least 30% by weight of the elements of a size less than 0.063 mm being derived from limestone rocks.

2. Compacted hydrocarbon coating according to claim 1 in which the thermoplastic additive is a thermoplastic polyester obtained by polymerization of at least one hydroxy acid of formula (I): HO-C(O)-R-CR'(OH)-R” (I) in which: R is a saturated or unsaturated, optionally branched, C8-C20 aliphatic hydrocarbon chain, optionally comprising one or more oxygen atoms, comprising a linear main chain of at least 8 carbon atoms, R', R” each represent, independently of one another, H or a C1-C10 aliphatic hydrocarbon chain.

3. Compacted hydrocarbon coating according to claim 1 or 2, characterized in that the hydrocarbon coating comprises from 3% to 12% by weight of hydrocarbon binder relative to the total weight of the compacted hydrocarbon coating.

4. Compacted hydrocarbon coating according to any one of claims 1 to 3, characterized in that the compacted hydrocarbon coating is a PMA (Porous Mastic Asphalt) type coating.

5. Compacted hydrocarbon coating according to any one of claims 1 to 4, characterized in that the thermoplastic additive is the poly(ricinoleic acid) or poly(12-hydroxystearic acid).

6. Use of a thermoplastic additive as described in claim 1 or 2 for improving the compactibility of hydrocarbon coatings intended to be compacted, the hydrocarbon coatings comprising a hydrocarbon binder and solid particles, the solid particles comprising elements having a size less than 0.063 mm, at least 30% by weight of these elements being derived from limestone rocks.

7. Use of a thermoplastic additive as described in claim 1 or 2 for improving targeted segregation during the preparation of a compacted hydrocarbon coating of the PMA (Porous Mastic Asphalt) type.

8. Use of a compacted hydrocarbon coating as described in any one of claims 1 to 5 for the manufacture of road surfaces, urban developments or waterproofing layers for structures and buildings.

9. Method for preparing a compacted hydrocarbon coating as described in any one of claims 1 to 5 comprising the following successive steps: a) preparation of a hydrocarbon coating by mixing solid particles, a hydrocarbon binder and a thermoplastic additive as described in claim 1 or 2, the content of thermoplastic additive ranging from 0.1 to 5% by weight, relative to the weight of the hydrocarbon binder, the solid particles comprising elements having a size less than 0.063 mm, at least 30% by weight of these elements being derived from limestone rocks; b) spreading the hydrocarbon coating obtained in step a); c) compacting the hydrocarbon coating.

10. A preparation method according to claim 9, wherein steps a) and b) are carried out at a temperature ranging from 110°C to 170°C.

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