CH706801A2 - Asphalt composition flowed for taxiways coatings stick properties. - Google Patents

Abstract

The present invention relates to a cast asphalt composition comprising in mass, with respect to its total mass, at least (i) 5 to 20% of a hydrocarbon binder, (ii) 75 to 94.5% of mineral fillers, characterized in that that the mineral fillers comprise at least, by weight relative to the total mass of the asphalt composition, from 20 to 40% of fines, from 15 to 45% of sands and from 20 to 55% of gravel, and in that the asphalt composition comprises (iii) 0.5 to 5% light aggregates of actual density less than 1.5. The invention also relates to a coating for traffic lanes obtained from said composition characterized in that the adhesion of its surface in the new state has a standardized value according to the standard NF EN 14231 greater than 30.

Description

The present invention relates generally to a cast asphalt composition for constructing taxiway pavements with adherent properties, said composition comprising light aggregates of low real density.

In the road domain, a poured asphalt is conventionally a dense and porosity-free material comprising a binder, generally of the bituminous type, and mineral fillers consisting of fines having a particle size of less than 63 μm, sand having a particle size of between 63 μm and 2mm, and gravel of particle size between 2mm and 14mm approximately. The composition in mineral fillers is chosen so as to minimize the voids of the mineral skeleton (the mineral skeleton being constituted by mineral fillers, including fines). The volumetric content of the binder depends on the volume of the voids of the mineral skeleton.

The cast asphalt is manufactured by gradually mixing the different mineral fillers in the binder carried in the liquid phase by raising the temperature, and by continuously mixing the mixture to maintain its homogeneity.

The homogeneous mixture is then hot cast and solidifies by simple cooling. The mastic asphalt coating thus obtained is usable in the state and without complementary compaction. The mechanical properties of the cast asphalt pavement depend on the percentages and nature of the various components (mineral fillers and binder). Indeed, the dosage between the amounts of binder and mineral fillers gives the mastic asphalt its three fundamental properties are the ability to be hot cast, sealing and wear resistance.

According to its mechanical properties, the cast asphalt coating may be a coating particularly suitable for the following uses: - traffic lanes for light and heavy vehicles (road surfaces, car parks, ramps, and industrial floors, for example), - pedestrian traffic lanes (town sidewalks, pedestrian walkways, and terraces for example), - layers of protection of the seals of terraces of buildings or civil engineering works.

Asphalt pavements cast in new condition and without any surface treatment may have a smooth and slippery surface that can cause falls of users (pedestrians, cyclists, skateboarders ...). This disadvantage is particularly observed during the first weeks or months after the application of the mastic asphalt coating because with time and use, the surface of the mastic asphalt coating undergoes a natural abrasion related to the passage of users and / or weather that causes an increase in its adhesion.

The smooth surface and the slipperiness of a cast asphalt coating in new condition is due to the presence of a thin layer of bituminous mastic (binder mixture more filler) on the surface of the coating, most of aggregates being covered by this thin layer of mastic.

In the field of road, several techniques have been developed to overcome the slipperiness problem of a new asphalt coating by increasing the adhesion of its surface. For example, large aggregates, such as chippings of 2/4 particle size, may be sprinkled on the surface of the hot asphalt. The presence of gravel protruding from the surface of the new asphalt coating increases the adhesion of the surface of said coating and decreases its slipperiness. Even if afterwards the chippings are removed because of a natural abrasion associated with the use, this abrasion will generally have made it possible to increase satisfactorily the adhesion of the coating. However, the dusting technique has the disadvantage of generating heterogeneous and unsightly surfaces.

It may also be mentioned the technique of float or sweep which consists in applying to the surface of the hot asphalt small aggregates such as dry and fine siliceous sandblasts having a particle size of 0.1 to 1 mm. This technique allows a better homogeneity and adhesion of the surface of the asphalt coating compared to the dusting technique of gravel. However, the technique of float or sweep requires perfect control not to create folds on the surface or unsanded areas that degrade the aestheticism of the coating.

Another technique which is described in FR2774090 is to increase the density of mastic (binder mixture filler) of the asphalt composition so that the chippings are lighter than the mastic and they appear on the surface of the asphalt pavement. This technique increases the adhesion of the surface of the asphalt coating but it has the disadvantage of being expensive.

Other techniques such as blasting or sandblasting under pressure consist in carrying out a mechanical treatment after cooling the poured asphalt coating. Sandblasting has the disadvantage of generating a lot of soiling during the treatment. Shotblasting can sometimes reveal a phenomenon of "lineage" at the crossing of the passes. Moreover, these techniques have the disadvantage of being expensive.

It is also known from the state of the art EP 2 151 474 which describes a bituminous conglomerate comprising by weight relative to its total mass: 7.6% of a hydrocarbon binder; 14% of fines; 20% sands; 37.4% gravel; 18% light aggregates and 3% rubber granules.

EP 1 605 022 discloses a construction material, such as asphalt for producing road surfaces. The material comprises, by weight relative to the total mass of the material: 3 to 15% of a binder usually used for road construction; 20 to 80% gravel; from 5 to 50%, preferably from 10 to 40% and especially from 15 to 30% of light aggregates. In particular, the chippings consist of a limestone matrix in which are embedded grains of crushed quartz sandstone. The material may also include sand and stone dust (fillers) and a rubber-based additive.

Finally, it is known from the state of the art, the document EP 1502 994 which describes a bituminous concrete comprising, in mass relative to the mass of bituminous concrete, a binder, a granular filler composed of 45% to 70% conventional 4/6 aggregates, 10 to 25% alveolar aggregates; from 15 to 35% of conventional granules of particle size 0/2, and 0 to 5% of filler, and 0 to 5% of additive. This document does not thus refer to a cast asphalt composition.

One of the aims of the invention is therefore to formulate cast asphalt compositions which make it possible to obtain asphalt coatings having, in addition, improved adhesion properties when new, satisfactory mechanical properties, a surface homogeneous and low cost.

In the context of the present invention, unless otherwise specified, the indication of a range of values from "X to Y" or "between X and Y" is understood to include the X and Y values.

[0017] Also, unless otherwise specified, the words "less than Z" or "greater than Z" are understood to include the value of Z, while the statement "Strictly less than Z" or "strictly greater than Z" means not including the value of Z.

The invention relates to a cast asphalt composition comprising in mass, with respect to its total mass, at least (i) from 5 to 20% of a hydrocarbon binder, (ii) from 75 to 94.5% of fillers. characterized in that the mineral fillers comprise at least, by weight relative to the total weight of the asphalt composition, from 20 to 40% fines, from 15 to 45% sands and from 20 to 55% by weight. gravel, and in that the asphalt composition comprises (iii) 0.5 to 5% light aggregates of actual density less than 1.5 (value of 1.5 inclusive).

In preferred embodiments, the cast asphalt composition according to the invention has the following characteristics alone or in combination: The light aggregates have a particle size of less than 8 mm, preferably less than 4 mm, and more preferably less than 2 mm; The light aggregates have a real density of between 0.5 and 1.5 and possibly strictly less than 1.5; The light aggregates represent, in mass of the total mass of the composition, from 0.5 to 5%, preferably from 1 to 5% and typically from 0.5 to less than 5% (value of 5% not included) ; The light aggregates are chosen from expanded clays, expanded shales, expanded recycled glass beads or beads, non-fusible polymer beads or beads at the processing temperature of the mastic asphalt, in particular at a temperature ranging from from 160 to 230 ° C, preferably at a temperature above 160 ° C; The light aggregates are expanded clay beads or expanded recycled glass beads with a particle size of less than 2 mm; The hydrocarbon-based binder represents from 5 to 20%, preferably from 6 to 9%, by weight of the total mass of the composition; The hydrocarbon binder is a pure or modified or hard bituminous binder preferably chosen from bituminous binders of class less than 70-100, that is to say from binders having a penetrability at 25 ° C. measured according to the NF standard EN 1426 less than 100 1/10 <em> mm; The fines represent from 20 to 40%, preferably from 20 to 35%, by weight of the total mass of the composition; The fines can be of any mineral nature, preferably of calcareous type; - The chippings represent from 20 to 55%, preferably from 25 to 45% by weight of the total mass of the composition; - The chippings are preferably selected from the grain sizes for which the largest dimension D is between 4 and 14 mm; The sands represent from 15 to 45%, preferably from 20 to 40% by weight of the total mass of the composition; The sands are preferably semi-crushed or rolled sands of 0/4 or 0/2 particle size.

The nature and proportions of the various components of the asphalt composition according to the invention are preferably chosen according to the specifications of EN 13108-6 so as to obtain an asphalt coating having the desired mechanical properties, that is to say, the mechanical properties adapted to climatic conditions, traffic loads, types of loads, and use.

The invention also relates to a taxiway liner having adhesion properties, such as a road, a bicycle path, or a pedestrian route, said coating being obtained from a cast asphalt composition. according to the invention.

Light aggregates are distributed on the surface of the traffic lane pavement according to the invention; they thus protrude on the surface of said coating. Advantageously, the light aggregates are distributed homogeneously on the surface of the lane lining according to the invention.

Preferably, the adhesion of the surface of the lining of traffic lanes in the new state according to the invention has a standardized value according to the standard NF EN 14231 greater than 30.

By "cast asphalt composition" is meant the mixing of the various components of a cast asphalt before their implementation by hot casting to form a coating of asphalt.

By "coating" means the cooled material obtained after the implementation (mixing and casting) of the cast asphalt composition.

By "adherent properties" is meant the properties of the surface of the coating subjected to the circulation which limits the relative movement between the contact area of the shoe sole of a pedestrian (sliding) or a tire. of vehicle (skid) and this surface.

"Mineral fillers" means the aggregate charge not comprising light aggregates of actual density less than 1.5.

The hydrocarbon binder according to the invention is chosen from hydrocarbon binders essentially based on bitumen or synthetic binders made from raw materials of petroleum origin or from biomass, and conventionally used to produce layers and and / or road construction and / or civil engineering coatings. The bitumens of the invention may be prepared by any conventional technique. According to the present invention, the bitumen is a mixture of hydrocarbon materials of natural origin resulting from the heavy fraction obtained during the distillation of petroleum, or coming from natural deposits in solid (natural asphalt) or liquid form, with a density of between 0.8 and 1.2. According to the invention, the bitumen may be a "pigmentable bitumen", that is to say a bitumen obtained after removal of asphaltenes from the heavy fraction (the latter consisting of viscous oils of black hue). A "pigmentable bitumen" can be colored by adding various pigments. According to the invention, the bitumen can also be a "clear bitumen", that is to say a clear mixture of oils and resins or clear oils and elastomers, substitutable for bitumen in poured asphalts. A "clear bitumen" with the use of suitable pigments makes it possible to obtain poured asphalts of various colors. Bitumen within the meaning of the invention are also admitted binders of plant origin such as Vegecol®, marketed by Colas and described in patent application FR 2 853 647, synthetic binders of petroleum origin. such as the range of binders Bituclair <®> marketed by Colas, binders of vegetable and petroleum origin such as binders Vegeclair <®> marketed by Colas, bitumens modified by incorporation of additives of any kind such additives with a view to improving the adhesiveness characteristics by incorporation of elastomers, in the form of rubber crumb or the like, or else the bitumens improved by the addition of polymers of different types, such as copolymers of ethylene and vinyl acetate, or random or block copolymers of styrene and conjugated dienes, for example SBS block copolymers. It is also possible to use mixtures of bitumens of different types.

In a preferred embodiment, the hydrocarbon binder is a pure bitumen in accordance with the NF EN 12591 standard; it is selected from grades 20-30, 30-45, 35-50, 40-60, 50-70, 70-100, 100-150, 160-220, 250-330, preferably from grades below 70 -100, for example among the grades 20-30, 30-45, 35-50, 40-60, 50-70 and 70-100. The figures for each of these grades correspond to the range of penetrability measured according to standard NF EN 1426. In another preferred embodiment, the hydrocarbon binder is a bitumen modified with polymers and complies with the standard EN 14023. The modified bitumen is selected from grades 10-40, 25-55, 45-80, 40-100, 65-105, 75-130, 90-150, 120-200, 200-300, and more preferably is selected from grades less than 70-100, for example among grades 10-40, 25-55 and 45-80. In a particular embodiment, the hydrocarbon binder is a hard bitumen in accordance with EN 13924; he is chosen from grades 10-20 and 15-25.

The hydrocarbon binder according to the invention represents from 5 to 20%, preferably from 5 to 10%, and more preferably from 6 to 9%, by weight of the total mass of the composition. The binder content is chosen according to the void percentages of the mineral skeleton (fines, sands and chippings) and light aggregates of the asphalt composition according to the invention, and also according to the desired use of this composition. The binder content is for example chosen according to the specifications of standard NF EN 13108-6.

The mineral fillers according to the invention have an actual density greater than. 1.5. The mineral fillers according to the invention represent, for example, from 70 to 94.5%, from 75 to 94%, from 75 to 94.5%, from 71 to 93.5%, from 85 to 94%, from 86 to 93%. % by weight of the total mass of the composition.

The mineral fillers according to the invention are chosen from fines, fillers, sands and chippings. Fine, fillers, sands and chippings are aggregates preferably meeting the specifications of NF EN 13043. A granulate can be natural, artificial or recycled. The natural granulate is a granulate of mineral origin that has not undergone any transformation other than mechanical. Artificial granulate is a granulate of mineral origin resulting from an industrial process including thermal or other transformations. Aggregates are generally referred to in terms of lower (d) and upper (D) sieve sizes, expressed as "d / D" corresponding to the granular class. This designation allows that grains can be retained on the upper sieve (refusal on D) and that others can pass through the lower sieve (passing to d). The aggregates are grain sizes of 0 and 125mm. The fines are a granular fraction of a granulate that passes through a sieve of 0.063 mm. A filler is a granulate with most grains passing through a 0.063 mm sieve; it can be added to building materials to give them certain properties. The sands are 0/2 aggregates according to standard NF EN 13043 for bituminous mixtures. Chippings are aggregates for which 2 <D <45 mm and d> 2 mm according to standard NF EN 13043 for bituminous mixtures and coatings.

According to the invention, the fines are of any mineral nature. They are preferably chosen from calcareous fillers. The granulometry of the fines according to the invention is preferably less than 63 μm. The fines represent from 20 to 40%, preferably from 20 to 35%, by weight of the total mass of the asphalt composition according to the invention, especially when they are calcareous type fillers.

According to the invention, the sands are preferably selected from semi-crushed or rolled sands. The granulometry of the sands according to the invention is preferably between 63um and 2mm. The sands are preferably selected from 0/4 and 0/2 granulometries, in particular when the sands are semi-crushed or rolled sands. The sands represent from 15 to 45%, preferably from 20 to 40%, by mass of the total mass of the asphalt composition according to the invention, in particular when they are semi-crushed sand of particle size 0/4 and / or 0/2.

According to the invention, the chippings are selected from chippings of any geological nature of density greater than 1.5 or possibly strictly greater than 1.5. The particle size of the chippings according to the invention is between 2mm and 14mm. The chippings are preferably selected from the particle sizes 2/6, 4/6, 6/10, and 10/14. The chippings represent from 20 to 55%, preferably from 25 to 45% by weight of the total mass of the asphalt composition according to the invention, especially when they have a particle size of 2/6 and / or 4/6 and and / or 6/10 and / or 10/14, and / or 2/4 and / or 4/8 and / or 4/10, or a mixture thereof.

According to the invention, the light aggregates are aggregates having a lower specific gravity than the mastic (binder mixture plus filler) of the mastic asphalt composition, advantageously at a temperature ranging from 160 to 230 ° C. that is, at a conventional casting temperature of an asphalt. Thus, from the application of the asphalt composition according to the invention, the light aggregates go back to the surface of the asphalt coating thus formed and are found immobilized on the surface of the coating once it has cooled.

In a preferred embodiment, the poured asphalt composition according to the invention comprises light aggregates of real density less than 1.5 (inclusive), preferably between 0.5 and 1.5, and in particular strictly less than 1.5. They represent from 0.5 to 5%, preferably from 1 to 5%, and in particular from 0.5 to less than 5% (limit not included) by weight of the total mass of the composition.

By actual density is meant the density of a single granulate and not the density of a volume of aggregates. Indeed, the density of a volume of aggregates corresponds to the apparent density, and this includes the volume of the voids. The actual density is measured by any known conventional techniques, for example by comparative weighing of a granulate of a given volume with the same volume of water.

Light aggregates according to the invention are selected from expanded clays, expanded shales, grains or beads of expanded recycled glass, grains or non-fusible polymer beads at the temperature of implementation of the cast asphalt. The temperature of implementation of the mastic asphalt typically ranging from 160 ° C to 230 ° C, the grains or beads of polymers according to the invention are preferably non-fusible in a temperature range from 160 ° C to 230 ° C, or from 190 ° C to 250 ° C. In particular, the melting temperature of the grains or polymer beads according to the invention is greater than the application temperature of the mastic asphalt according to the invention. The melting temperature of the grains or beads of polymers according to the invention is in particular greater than 160 ° C., or greater than 170 ° C., or greater than 180 ° C., or greater than 190 ° C., or greater than 200 ° C., or even greater than 230 ° C, for example greater than 250 ° C, and is chosen by the skilled person according to the specific conditions, in particular according to the temperature, of implementation of the cast asphalt. For example, the operating temperature of the cast asphalt is 195 ° C, and the melting temperature of the beads or polymer beads is greater than 195 ° C.

The light aggregates according to the invention can be crushed by any known method to obtain the desired particle size. In a preferred embodiment of the invention, the granulometry of light aggregates is less than 8 mm, preferably less than 4 mm, and more preferably less than 2 mm.

In a particular embodiment, the light aggregates of the invention are either light aggregates having a specific particle size, or a mixture of light aggregates having different particle sizes, these particle sizes being preferably chosen from particle sizes of between 0 and 8 mm, such as for example the 0/1, 0/2 and 1/2 granulometries.

Light aggregates suitable for the implementation of the invention are for example expanded clay beads of 0/2 particle size and / or expanded recycled glass beads of 1/2 particle size.

The granulometry or the mixture of granulometries of light aggregates is chosen so as to obtain a cast asphalt composition which preferably meets the specifications of the standard NF EN 13108-6. The light aggregates of the asphalt composition according to the invention replace some or all of the mineral fillers (fines, sands and chippings) conventionally present in a cast asphalt composition.

In a first embodiment, a part of the sands according to the invention, preferably representing from 1 to 20% by weight relative to the total mass of the composition, is replaced by at least 0.5 to 10% by weight. in mass relative to the total mass of the composition of light aggregates having a particle size of between 0 and 2 mm, such as, for example, a particle size of 0/2 or 1/2. When the light aggregates replace part of the sands, they are preferably chosen from the expanded clay balls of particle size 0/2 and the expanded recycled glass beads of particle size 1/2.

In a second embodiment, a part of the chippings according to the invention, preferably representing from 1 to 20% by weight relative to the total mass of the composition, is replaced by at least 0.5 to 10% by weight. in mass relative to the total mass of the composition of light aggregates having a particle size of between 2 and 8 mm, preferably selected from the grain sizes 0/5, 2/4, and 3/8.

A third embodiment consists in combining embodiments 1 and 2. Thus, in a particular embodiment, part of the sands and part of the chippings are replaced by light aggregates as described in the methods of the present invention. achievements 1 and 2.

The preferred asphalt compositions according to the invention are those comprising light aggregates replacing part of the sands.

Preferably, a poured asphalt composition according to the invention comprises, by weight relative to the total mass of the composition, at least (i) from 6 to 9% of a hydrocarbon binder, (ii) from 20 to at 35% fines, 20 to 40% sands, 25 to 45% gravel, (iii) 1 to 5% light aggregates with a specific gravity of less than 1.5 and a particle size of less than 2 mm.

The cast asphalt composition according to the invention is manufactured in a traditional manner, that is to say by gradual mixing of the various fillers (light aggregates and mineral fillers (fines, sands, chippings)) in the hydrocarbon binder. carried in the liquid phase by raising the temperature, preferably at a temperature ranging from 160 to 230 ° C, and more preferably from 160 to 200 ° C. The various components of the asphalt composition according to the invention, in addition the hydrocarbon binder, the light aggregates and the mineral fillers are mixed according to the proportions defined in the composition of the invention. They are then kneaded continuously, at a temperature ranging from 160 to 230 ° C., and better still from 160 to 200 ° C., for a minimum of 2 hours in order to maintain the homogeneity of the mixture until it is applied. Once poured and cooled, the mixture hardens and forms an asphalt pavement that can be used as traffic lanes. The thickness of the coating according to the invention varies for example from 15 to 40 mm, and preferably from 20 to 25 mm.

The asphalt according to the invention is cast in a traditional manner, that is to say in independence or adherence to any support in accordance with the rules of the art, with or without the interposition of a glass grid. As soon as the asphalt coating is applied and before cooling, the light aggregates rise to the surface of the still hot coating because they have a lower actual density than the mastic (binder mixture plus filler). Once the asphalt coating has cooled, the light aggregates are immobilized on the surface of the coating so as to protrude, that is to say so as to protrude above said surface in a more or less irregular. The light aggregates thus give the coating a surface roughness. Advantageously, the arrangement of light aggregates on the surface of the coating is homogeneous.

The cast asphalt coating according to the invention therefore has a natural surface roughness conferring properties of adhesion in the nine state better than those of a conventional asphalt. The higher the surface roughness of the coating, the higher the adhesion of the surface of the coating.

The adhesion properties of the coating of the invention are measured according to the test method SRT (Skid Resistance Tester) in accordance with the standard NF EN 14231. This method makes it possible to determine the adhesion of a surface, to the place under test, by means of a pendulum whose arm equipped at its end with a standard spring-loaded rubber pad is released from the horizontal position. The loss of energy caused by the friction of the pad on the surface is measured on a calibrated scale giving the decrease of oscillation amplitude of the arm. The value obtained on the calibrated scale corresponds to a standardized value of the adhesion, it is named "value of the pendulum test (VEP)". In a preferred embodiment, the coating according to the invention has, in the new state, a pendulum test value (VEP) according to standard NF EN 14231 greater than 30. "New condition" is understood to mean state of asphalt pavement after application and cooling and which has not undergone any surface treatment and / or has not been used.

The asphalt coating according to the invention has a mechanical strength measured according to the standard NF EN 12697-21 (indentation), similar to a traditional cast asphalt coating. Therefore, the coating according to the invention is any type of coating that a traditional cast asphalt coating can constitute, such as for example a lane covering (for pedestrians or for light and heavy vehicles), or still a protective coating seals terraces of buildings or civil engineering works.

Example 1

Composition 1 corresponds to a traditional cast asphalt composition, and compositions 2 and 3 to cast asphalt compositions according to the invention. The percentages are percentages by weight relative to the total mass of the composition. <tb> Bituminous Binder <SEP> 7.9% <SEP> 8.3% <SEP> 8.4% <tb> Filler limestone <SEP> 28.0% <SEP> 29.6% <SEP> 30.0% <tb> Sand 0/4 semi-crushed <SEP> 29.1% <SEP> 20.1% <SEP> 24.0% <tb> Chippings 4/6 <SEP> 35.0% <SEP> 37.0% <SEP> 36.6% <tb> Expanded clay balls 0/2 <SEP> / <SEP> 5.0% <SEP> / <tb> Expanded Recycled Glass Beads PORAVER <®> 1-2 mm <SEP> / <SEP> / <SEP> 1.0%

Example 2

The coating 1 corresponds to a traditional cast asphalt coating, and the coatings 2 and 3 to cast asphalt coatings according to the invention. The coatings 1, 2 and 3 are respectively obtained from the cast asphalt compositions 1, 2 and 3 of Example 1. <tb> Casting temperature <SEP> 195 ° C <SEP> 195 ° C <SEP> 195 ° C <tb> Pendulum test value (VEP) according to standard NF EN 14231, on the coating in new condition <SEP> 21 <SEP> 31 <SEP> 32 <tb> Aspect of the surface of the coating in new condition <SEP> smooth <SEP> rough <SEP> rough <tb> Indentation IB according to standard NF EN 12697-21, on the coating in new condition <SEP> 24 <SEP> 25 <SEP> 27

In new condition, the asphalt coatings 2 and 3 according to the invention have a pendulum test value much greater than that of the traditional asphalt coating 1. It should be noted that the average pendulum test value of a traditional asphalt pavement in new condition is 20 to 25. These results clearly show that, in new condition, asphalt pavements according to the invention have improved adhesion properties compared to a traditional asphalt coating.

The indentation IB according to the standard NF EN 12697-21 is a punching test which reflects the mechanical strength of the coating. The values obtained for coatings 1, 2, and 3 are similar. These results therefore show that in new condition, the asphalt pavements according to the invention have a mechanical strength similar to that of a traditional asphalt pavement.

Claims (11)

A cast asphalt composition comprising, by weight with respect to its total mass, at least (i) 5 to 20% of a hydrocarbon binder, and (ii) 75 to 94.5% of mineral fillers, characterized in that at least, by mass relative to the total weight of the asphalt composition, from 20 to 40% fines, from 15 to 45% sands and from 20 to 55% gravel, and in that the composition asphalt comprises (iii) 0.5 to 5% light aggregates of actual density less than 1.5. 2. A mastic asphalt composition according to claim 1, characterized in that it comprises, by weight relative to the total mass of said asphalt composition, at least (i) 6 to 9% of a hydrocarbon binder, ( ii) 20 to 35% fines, 20 to 40% sands, 25 to 45% gravel, (iii) 1 to 5% light aggregates of actual density less than 1.5 and particle size less than 8 mm. 3. Cast asphalt composition according to claim 1 or 2, characterized in that it comprises by mass relative to its total mass less than 5% of light aggregates. 4. Poured asphalt composition according to any one of claims 1 to 3, characterized in that the light aggregates (iii) have a specific gravity of between 0.5 and 1.5. 5. Poured asphalt composition according to any one of claims 1 to 4, characterized in that the light aggregates (iii) have a particle size less than 8 mm. 6. Poured asphalt composition according to any one of claims 1 to 5, characterized in that the light aggregates (iii) are selected from expanded clays, expanded shales, grains or beads of expanded recycled glass, grains or non-fusible polymer beads at the processing temperature of the mastic asphalt. Poured asphalt composition according to any one of claims 1 to 6, characterized in that the light aggregates (iii) are expanded clay balls of particle size 0/2 and / or recycled recycled glass beads. 1/2 particle size. 8. Poured asphalt composition according to any one of claims 1 to 7, characterized in that the fines has a particle size of less than 63 microns, the sand has a particle size selected from 0/4 and 0/2 and chippings present a particle size selected from 2/6 and / or 4/6 and / or 6/10 and / or 10/14 and / or 2/4 and / or 4/8 and / or 4/10, or a mixture thereof. 9. Roadway liner having adhesion properties obtained from a poured asphalt composition according to any one of claims 1 to 8. 10. Road lining according to claim 9, characterized in that the light aggregates are distributed on the surface of the coating. 11. Roadway lining according to any one of claims 9 or 10, characterized in that the adhesion of its surface in the new state has a standardized value according to standard NF EN 14231 greater than 30.