WO2025068300A1 - Compacted hydrocarbon-based coatings having improved workability and compactibility properties - Google Patents

Abstract

The present disclosure relates to a compacted hydrocarbon-based coating, comprising a hydrocarbon-based binder and solid particles and being devoid of surfactant. The hydrocarbon-based coating comprises from 0.1 to 5% by weight, relative to the weight of the hydrocarbon-based binder, of a thermoplastic additive chosen from a polymer having at least one carboxylic acid terminus, the polymer being a polyester, a polyamide, a poly(ester-amide), a polyether that is functionalised at the carboxylic acid chain end or a polydiene that is functionalised at the carboxylic acid chain end; or a thermoplastic polymer that is functionalised at the chain end by a succinic anhydride function, the polymer being a polyisobutene or a polystyrene. The solid particles comprise elements having a size of less than 0.063 mm, at least 30% by weight of these elements having a size of less than 0.063 mm originating from calcareous rocks.

Description

COMPACT HYDROCARBON COATINGS WITH IMPROVED WORKABILITY AND COMPACTIBILITY PROPERTIES

FIELD OF THE INVENTION

The present invention belongs to the field of hot-mix 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

Compacted hydrocarbon mixes represent the main component of roadways in France and worldwide. They are generally present in both base layers and wearing courses. The most widely used technique in roadway manufacturing 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, as opposed to emulsion hydrocarbon mixes such as "cold" mixes produced at room temperature, such as the cold-poured bituminous materials described in application FR 3 094 365. Emulsion hydrocarbon mixes are distinguished from "hot" hydrocarbon mixes in particular by the emulsification of the binder, which is essential to obtain adequate viscosity at room temperature. The problems that arise with emulsion-based hydrocarbon mixes therefore mainly concern the kinetics of breakage of the binder emulsion and obtaining sufficient coating of the solid particles. In "hot" hydrocarbon mixes, the binder is not emulsified, so the high temperatures used are necessary to reduce the viscosity of the binder and give sufficient workability and compactibility to the mix. A satisfactory coating is thus obtained and the mechanical properties of the mixes after installation and cooling are in line with the expectations of those skilled in the art.

The workability and compactibility properties of asphalt 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 significantly influence the cooling speed of the mixes. In addition, the high temperatures used in hot mixes represent significant and costly energy consumption. 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 mixes being affected. In particular, there is a need to improve the workability and compactibility properties of mixes at lower temperatures than conventional temperatures, while maintaining satisfactory mechanical properties, for example rutting resistance and fatigue resistance.

SUMMARY OF THE INVENTION

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 limestone rocks, and c. the hydrocarbon coating does not comprise a surfactant.

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, the coatings being free of surfactant.

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. 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.

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 content of thermoplastic additive ranging from 0.1 to 5% by weight, relative to the weight of the hydrocarbon binder, the mixture being free of surfactant, and the solid particles comprising elements having a size of 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.

Other aspects of the invention are as described in the claims or below.

DETAILED DESCRIPTION

The inventors of the present invention have, surprisingly, developed a hot mix formulation that can meet the aforementioned needs. Thus, the present invention relates to a compacted hydrocarbon mix comprising a hydrocarbon binder and solid particles, characterized in that: a. the hydrocarbon mix 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, and c. the hydrocarbon coating does not comprise a surfactant. 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 hot-mix hydrocarbon coatings.

The workability and compactibility of asphalt mixes represent two very distinct properties.

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 (water resistance) and good feathering 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, using the compactibility measurement test of asphalt mixes subjected to the gyratory shear press.

The workability of asphalt mixes is a sought-after property for good quality implementation, particularly to limit the arduousness of manual work. Workability allows the asphalt mix to be spread more quickly and easily on the road. It can be measured in the laboratory or on site, in particular using the method described in the experimental section.

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

The term "compacted asphalt" refers to a asphalt that has undergone a compaction stage. Indeed, after their manufacture, during implementation, the asphalts are compacted after spreading. Compacted asphalts are therefore distinguished from poured asphalts in particular by this compaction stage. 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.

The hot-compacted hydrocarbon coatings of the invention have mechanical properties consistent with those expected for wearing courses and base layers, in particular those described in standard NF EN 13108 (February 2007).

A hydrocarbon mix is distinguished from an emulsion hydrocarbon mix, for example a cold-poured bituminous material, which refers to a mix resulting from the mixing of solid particles and a hydrocarbon binder emulsion. The binder emulsion hydrocarbon is a dispersion of the binder in water comprising a cationic or anionic surfactant, or emulsifier, preferably cationic.

A surfactant is an amphiphilic molecule comprising a hydrophilic part having a strong affinity with water, and a hydrophobic and lipophilic part having a strong affinity with oils and fatty substances, in this case with the hydrocarbon binder. The cationic surfactant thus allows the formation of binder droplets in the water, thus leading to the formation of the binder emulsion.

The surfactants used for the preparation of emulsion coatings correspond in particular to the surfactants described in application FR 3 094 365, paragraphs [0159] to [0176],

The hydrocarbon coating of the invention is characterized in that it does not comprise a surfactant, since the hydrocarbon binder is not emulsified during the preparation of the coating. In particular, the surfactants described in application FR 3 094 365, paragraphs [0159] to [0176], are not present. Thus, the hydrocarbon coating of the invention does not comprise a surfactant, in particular an amine, for example alkylpolyamines, fatty amines, amidopolyamines, fatty chain quaternary ammoniums and combinations thereof. The hydrocarbon coating is particularly free of the following commercial products:

- DinoramOS (Ceca) or Redicote®E9 (Akzo Nobel): N alkyl tallow propylene diamine;

- Emulsamine®L 60 (Ceca): Preparation based on tall oil fatty amide, N-(3-dimethylamino)propyls (> 50%) and Emulsamine®LZ (> 25%) with an aromatic hydrocarbon (> 1%) and diethanolamine (> 1%);

- Polyram®S (Ceca): N-alkyl tallow propylene polyamine with Dinoram®S (< 10%), tallow alkyl amines (Noram®S - < 5%), tallow nitrile (< 10%);

- Stabiram®MS 601 (Ceca): solution of N-alkyl tallow N-dimethyl amino propyl N-trimethyl ammonium dichloride (> 50%) in a water/hexylene glycol mixture (glycol > 20%) with Dinoram®S (< 1%);

- Dinoram®O (Ceca): N-(C16 and C18 alkyl unsaturated) trimethylene diamine (oleic diamine);

- Emulsamine®640 (Ceca): Preparation based on tall oil fatty amides (> 50%), Dinoram®O (> 25%) and (Z)-octadec-9-enylamine (> 1%);

- lndulin®R 66 (Meadwestvaco): Tall oil fatty amides: N - [(dimethylamino)-3-propyl];

- I ndulin®R 33 (Meadwestvaco): Tall oil fatty amides (N-[(dimethylamino)-3-propyl]) (75-90%), N-tallow alkyltrimethylenediamine (20-25%);

- lndulin®GE F2 (Meadwestvaco): Nonylphenol ethoxylate (25-35%), alkali lignin (reaction produced with dimethylamine and formaldehyde) (15-20%), N-(C14-18 alkyl and C16-18 unsaturated)-trimethylenediamine (5-10%); - lndulin®GE F2 (Meadwestvaco): C12-C14 ethoxylated alcohols (2.5-25%), alkaline lignin (reaction produced with dimethylamine and formaldehyde) (10-20%), N-(C14-18 alkyl and C16-18 unsaturated)-trimethylenediamine (1-3%);

- Duomeen®TTM (Akzo Nobel): tallowtrimethylpropylenediamine (90-100%), tallowdimethylamine (5-10%);

- Redicote®404 (Akzo Nobel): tall oil, reaction products with tetraethylenepentamine (100%).

Hydrocarbon binder

A “binder” for the purposes of the present invention is a material whose thermoplastic properties enable it to harden upon cooling and bind solid particles together.

The term "hydrocarbon binder" refers to any binder of fossil, plant, or synthetic origin that can be used to produce so-called "bituminous" products. The hydrocarbon binder can be bitumen, and be pure or modified, in particular by the addition of polymer(s), fibers, or pigments.

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

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 not 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,

- copolymers of ethylene and esters of acrylic acid, methacrylic acid or maleic anhydride, copolymers and terpolymers of ethylene and glycidyl methacrylate and polyolefins.

The bitumen-modifying polymers can 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 (PIARC) 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.

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.

In the context of the invention, the hydrocarbon binder is not emulsified.

Solid particles

The term "solid particles" refers to all solid particles that can be used to produce road and development products, particularly those that can be used to produce compacted hydrocarbon coatings.

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

Solid particles, particularly mineral solid particles, e.g., natural mineral aggregates, typically include:

- 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 with a size ranging from 2 mm to 6 mm and elements with a size greater than 6 mm, for example up to 40 mm (which are provided by/correspond to gravel or coarse aggregates).

In other words, the fines consist of elements passing through the 0.063 mm sieve, the elements with a size ranging from 0.063 mm to 2 mm consist of elements retained in the 0.063 mm sieve but passing through the 2 mm sieve and the elements with a size ranging from 2 mm to 6 mm and elements having a size greater than 6 mm are made up of elements retained in the 2 mm sieve.

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).

“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 from 0 to 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 up to approximately 40 mm) constitute the d/D mineral fraction.

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.

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.

Limestone rocks are composed mainly of calcium carbonate, meaning they contain at least 50% calcium carbonate by weight. Calcium carbonate will interact with the thermoplastic additive.

Elements larger than 2 mm (e.g. gravel) may or may not be derived from limestone rock. When compacted asphalt is used as a wearing course, the gravel is generally not derived from limestone rock (it generally contains little or no calcium carbonate).

Thermoplastic additive

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 hot-mix hydrocarbon mixes. In other words, this thermoplastic additive makes it possible to obtain compactibility and workability comparable to those obtained with hot-mix mixes (i.e. at temperatures of the order of 180°C to 200°C) using temperatures of lower manufacturing and implementation temperatures, typically of the order of 80°C to 170°C, in particular 110°C to 170°C or 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.

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.

The application temperature of a hydrocarbon coating refers to the temperature of the coating during its application, more specifically the temperature of the coating in the paver screw before the smoothing table or the temperature of the coating after the smoothing table before compaction.

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.

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.

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.

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 include sodium hydroxides, potassium hydroxides, calcium hydroxides and/or oxides, magnesium hydroxides and/or oxides, ammonia, or mixtures thereof.

The thermoplastic additive useful in the context of the invention is a polymer, that is to say 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.

The polymer is advantageously linear.

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

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.

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.

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

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 C1-C10.

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 that may be saturated or unsaturated. Unsaturation, when present, is advantageously a C=C double bond or a C=C triple bond, more preferably a C=C double bond. In one embodiment, R is a hydrocarbon chain that comprises 0 to 3 C=C double bonds, advantageously 0 to 2 C=C double bonds, more preferably 1 C=C double bond;

R is a C8-C15 hydrocarbon chain, more preferably C10-C15, even more preferably C10.

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

Advantageously, R’ represents H or a linear, saturated, aliphatic hydrocarbon chain, more advantageously C1-C4. More advantageously, R’ represents H.

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.

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

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.

In some 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.

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.

The dicarboxylic acid is advantageously sebacic acid, azelaic acid, adipic acid, glutaric acid, succinic acid, maleic acid, itaconic acid, and mixtures thereof.

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.

The polyester may also be obtained by ring-opening polymerization of a lactone and be terminally 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.

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.

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

Advantageously, the diamine is an alkyl diamine or an alkenyl diamine or an alkynyl diamine, more advantageously C4-C20. For example, we can notably cite tetramethylene diamine, hexamethylene diamine, or decanediamine.

Polyamides may also be prepared by ring-opening polymerization of lactams, particularly lactams comprising at least 5 carbon atoms.

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.

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 previously.

In some embodiments, the thermoplastic polymer is a carboxylic acid end-functionalized polyether or a carboxylic acid end-functionalized polydiene. Thus, the carboxylic acid functionality is introduced by modification of a polymer.

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

The polyether is advantageously polytetrahydrofuran or polypropylene glycol.

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

In particular, the polymer may 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, lactide or cyclic anhydride with a mono or dihydroxytelechelic polyether.

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.

The diacid may be a dicarboxylic acid as defined above.

The cyclic anhydride can contain from 4 to 10 ring carbon atoms.

Advantageously, the thermoplastic additive is poly(ricinoleic acid) or poly(12-hydroxystearic acid).

The thermoplastic additive interacts with the solid limestone particles (i.e. the solid particles from limestone 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, C1-C10, to improve the compactibility of the hydrocarbon coatings intended to be compacted.

Handling additives

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

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.

Compacted hydrocarbon coatings and their uses

A hot-compacted asphalt mix of the present invention may be a conventional asphalt mix or a so-called PMA (Porous Mastic Asphalt) mix. These mixes are distinguished from each other in particular by the particle size distribution of the solid particles. They do not include a surfactant. Conventional coatings

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 GB (Grave Bitume, NF EN 13108-1 of February 2007) or High Modulus Asphalt, or in wearing courses, for example BBSG (Semi-Granular 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).

Standard asphalt mixes are typically made up of sand, gravel and limestone fillers (from limestone rocks).

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.

Gravel is made up of elements with a size D greater than 2 mm and typically less than or equal to 6 mm.

Limestone fillers are made up of elements smaller than 0.063 mm.

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

The usual coatings of the invention, such as Grave Bitume, typically have the following particle size distribution: elements of size less 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 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.

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 preparing base layers (e.g. Bitumen Gravel) is calcareous. 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.

The usual coatings of the invention typically have a percentage of voids after compaction 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.

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.

In conventional asphalt mixes, the thermoplastic additive makes it possible in particular to improve the compactibility and workability of the asphalt 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°C to 160°C.

PMA coatings

By definition, PMA asphalt mixes have a heterogeneous structure after spreading/application, which includes 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.

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).

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

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

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

The top layer is typically 0.3 cm to 1 cm thick, with a thickness of about 0.5 cm. The top layer typically accounts for 10% to 25% of the total thickness of the PMA.

After compaction, the top layer comprises a void volume typically ranging from 15% to 30% of the volume of the entire PMA mix.

The bottom layer consists of the same granular skeleton as the top layer and an asphalt mastic filling the interstices of the granular skeleton. The bottom layer of the PMA has a thickness generally ranging from 2.5 cm to 5 cm. The bottom layer of the PMA typically represents 75 to 90% of the total thickness of the PMA. This bottom layer includes a void volume typically ranging from 0 to 5% of the volume of the layer, after compaction.

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

Sand, which may or may not be calcareous, is typically made up of a fine fraction and a coarse fraction.

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

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.

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.

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.

A PMA mix is obtained by hot pouring 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.

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 hot mixes, for example ranging from 80°C to 170°C, preferably from 110 to 170°C or from 120 to 160°C.

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 into 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 is done efficiently and quickly during the manufacture of the 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, the 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.

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 hot-mix hydrocarbon mixes, makes it possible to act on the lubrication of the asphalt mastic and to promote targeted segregation during the preparation of 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.

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

The preparation of the compacted hydrocarbon coatings according to the invention comprises the following steps: a) preparation of the 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, the mixture being free of surfactant, and the solid particles comprising elements having a size of 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) compacting the coatings.

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.

In step a), the hydrocarbon binder is not emulsified. The mixture of solid particles, hydrocarbon binder and additive does not contain water or surfactant, in particular a surfactant as described above.

The coatings are spread using a paver or a grader, for example. The compacted hydrocarbon coatings according to the invention allow for traffic to be put back into service in less than 72 hours, and more advantageously within 24 hours after spreading.

Compaction is carried out in such a way 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.

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. sidewalks) or waterproofing layers for structures and buildings.

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.

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

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

FIGURES

Figure 1A (top) shows a schematic of the operation of the manifold meter.

Nynas in operation, in which a lever arm exerts a thrust shear force on a layer of asphalt placed in the manifold mold. Figure 1 B (bottom) is a photo of a Nynas device.

Figure 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.

Figure 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 bitumen as a reference, as described in example 1.

Figure 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.

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

2.

Figure 6 represents the arithmetic mean height Sa (surface) of a coating

PMA according to the invention and a reference PMA coating as described in example 3, as a function of temperature.

EXAMPLES

• METHODS

Maneuverability measurement using a NYNAS maneuverability meter

The Nynas workability meter is a commonly used instrument for measuring the workability of asphalt mixes. This measurement determines how easily the mix can be placed. and compacted on the road surface. Workability is defined as a maximum cohesive force 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 force.

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.

The Nynas workability tester contains a mold into which a layer of asphalt is poured at the application temperature. A photo of a Nynas device is shown in Figure 1 B. 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. Workability corresponds to the value of the force exerted by the lever arm during the debonding 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 temperature.

Compactibility measurement: PCG test

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.

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.

For each temperature and for each asphalt mix, the percentage of voids in the asphalt 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

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:

[Table 1]

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

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

Compactibility

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

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

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 Figure 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

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

The results are presented in the following table: [Table 2]

Example 2: GB 0/14 35/50 base coating

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 bitumen 35/50 without thermoplastic additive are given in the following table: [Table 3]

Unless otherwise stated, percentages are expressed by weight relative to the total weight of the coating. The thermoplastic additive is marketed by Oléon under the name Nouracid CE 80, CAS no.: 68604-47-7.

Compactibility

A PCG test as described above is carried out on both 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 both mixes. The curve representing the number of gyrations to obtain the target compactness as a function of temperature is shown in Figure 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. thermoplastic polyester in the coatings of the invention therefore makes it possible to obtain a gain in compactibility of 60°C.

Workability 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 Figure 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

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

Exemple 3 : Enrobé PMA (Porous Mastic Asphalt) : The results are presented in the following table: [Table 4]

Example 3: PMA (Porous Mastic Asphalt) coating:

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:

[Table 5]

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

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

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

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. 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 shown in Figure 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 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

Tl 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, c. the hydrocarbon coating does not comprise a surfactant. 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 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, C1-C10. 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 poly(ricinoleic acid) or poly(12-hydroxystearic acid). 6. Use of a thermoplastic additive as described in claim 1 or 2 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 having a size less than 0.063 mm, at least 30% by weight of these elements being derived from limestone rocks, the hydrocarbon coatings being free of surfactant. 7. Use of a thermoplastic additive as described in claim 1 or 2 to improve 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 mixture being free of surfactant, and 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. Preparation method according to claim 9, in which steps a) and b) are carried out at a temperature ranging from 110°C to 170°C.