KR101983683B1 - A bituminous pavements composition for upper layers of roads comprising particles of expandable organic polymers - Google Patents

Abstract

The present invention relates to a bituminous packaging composition comprising an aggregate mixture, at least one hydrocarbon-based binder and foamable organic polymer particles, and a method of making the same, having a noise-preventing property.
The present invention also relates to the use of such a composition for the implementation of the top layer as a noise barrier and to the top layer as a noise barrier based on such a composition.

Description

[0001] The present invention relates to a bituminous pavement composition for upper layers of roads comprising foamable organic polymer particles,

The present invention relates to a bituminous composition for an upper layer of a paved road which can reduce general noise caused by traffic and a method of manufacturing the same.

Vehicle traffic on the road causes noise pollution. Such noise pollution, commonly referred to as road rubber wheel contact noise or BCPC, is important in road sites, such as in residential areas, cities or around the city, depending on traffic volume, traffic configuration and traffic speed (e.g., fast or heavy) .

It is necessary to reduce the noise pollution due to the passage of the vehicle on the running floor of the road.

The capacity of the running layer, which reduces the noise pollution caused by the road rubber wheel contact noise (BCPC) of the vehicle, depends on the nature of the running layer, the traffic condition, the weather condition, and is influenced by traffic and / It is a parameter that decreases with time as a result of changes in the properties of the layer.

A study of road rubber wheel contact noise (BCPC) has shown that most of this noise depends on the material of the road and the sound absorption capacity of the running layer. The reduction of the noise is dependent on the thickness, quantity and distortion of the communicating cavity and the particle size of the surface aggregate.

In addition to the passage, especially in the middle of the city, the pores existing in the upper part of the road are filled and the acoustic performance is reduced, which is caused by the reduction of the voids existing in the traveling layer. In order to prevent this inevitable loss of void volume, some methods consist in always making the grain size of the package more open (sand-free packaging composition with increased void content).

The Applicant has surprisingly found the use of foamable organic polymer particles which are particularly advantageous in obtaining a noise-attenuating package. These foamable organic polymer particles fill the pores present in the road pavement.

First of all, surprisingly, the presence of these particles in the pores of the running layer does not change the acoustic properties and can even improve the acoustic properties in some cases.

These beads or particles also serve to absorb or mitigate the impact. The presence of these particles can prevent the air gap network from being filled. The filling of the pore network is one of the causes that the acoustic characteristics are lost over time as mentioned above. By preventing such burial, it is possible to keep the acoustic characteristics almost constant over time while preventing deformation of the air gap network.

The presence of these particles can also improve their performance in terms of resistance to climate change. In fact, water no longer easily enters the pores. In addition, since the water can not penetrate, the breaker is prevented from bursting or expanding. This phenomenon is more prominent when hydrophobic organic polymer particles are used.

Finally, introduction of these particles can be realized, for example, simply by mixing them together with all the constituents of the package in a kneader. The manufacturing method does not require a complicated modification of the manufacturing process or the use method of the package. The organic polymer particles naturally fill the pores of the package.

Further, the present invention aims at a particle composition for road upper layer that can reduce general noise caused by road traffic. When the composition is intended for the production of a traveling layer, it is preferable that the composition has a general performance or characteristics expected to be expected in the packaging of the traveling layer,

- Good mechanical performance under most traffic,

- surface properties which ensure good adhesion between rubber wheels and roads, especially in wet times,

- said performance and characteristics, of which the noise reduction performance and persistence of characteristics,

- In terms of sustainable development, recyclability,

- Satisfactory aesthetic aspects, and

- Ease of use in production and application

This induces a layer to be demonstrated.

The above objects are achieved by a bituminous packaging composition for road top layers comprising an aggregate mixture and at least one hydrocarbon based binder,

a) the aggregate mixture satisfies the following conditions:

0 to 25 mass%, preferably 10 to 20 mass%, and more preferably 10 to 15 mass% of the constituent components of the aggregate mixture are 0/2 mm aggregate,

70 to 95 mass%, preferably 75 to 90 mass%, more preferably 85 to 90 mass% of the constituents of the aggregate mixture are 2/4 mm and / or 4/6 mm, preferably 2/4 mm Aggregate,

b) the composition further comprises foamable organic polymer particles

.

The present invention is also directed to a process for the production of the above defined top layer pavement composition, to the use of such a composition for the implementation of the top layer as a noise barrier, and to the top layer as a noise barrier based on such a composition.

The compositions for road top layers may be obtained either alone or in all possible technical combinations thereof and have the following characteristics which represent the specific advantages of the individual:

- the foamable organic polymer particles comprise graphite microparticles,

The foamable organic polymer particles have an apparent density of less than 100 kg / m ³ , or 15 to 50 kg / m ³ , preferably 20 to 35 kg / m ³ , more preferably 25 to 30 kg / m ³ ,

- the foamable organic polymer particles have a particle size of 0.1 to 5 mm, preferably 0.5 to 3.58 mm, more preferably 1 to 4 mm, more preferably 1 to 3 mm,

- the foamable organic polymer particles are 0.1 to 1% by mass, preferably 0.1 to 0.5% by mass, more preferably 0.2 to 0.3% by mass, based on the total mass of the packaging composition,

The foamable organic polymer particles are added at a rate of 50 to 200 liters per ton of the packaging composition except for the particles,

- The aggregate mixture satisfies the following conditions:

- 70 to 100 mass% of the constituents of the aggregate mixture have dimensions less than 6.3 mm,

- 70 to 100 mass% of the constituents of the aggregate mixture have dimensions less than 4 mm,

- 10 to 40 mass% of the constituents of the aggregate mixture have dimensions less than 2 mm,

- 1 to 9 mass% of the constituents of the aggregate mixture have dimensions less than 0.063 mm,

Preferably, the aggregate mixture satisfies at least one of the following conditions:

100% by weight of the constituents of the aggregate mixture have dimensions less than 6.3 mm, and / or

Not more than 95 mass%, preferably not more than 90 mass% of the constituents of the aggregate mixture have a dimension of less than 4 mm, and / or

- at least 75 mass%, preferably at least 85 mass% of the constituents of the aggregate mixture have a dimension of less than 4 mm, and / or

Not more than 35 mass%, preferably not more than 30 mass% of the constituents of the aggregate mixture have a dimension of less than 2 mm, and / or

At least 15 mass%, preferably at least 25 mass% of the constituents of the aggregate mixture have a dimension of less than 2 mm, and / or

- 4 to 8 mass% of the constituents of the aggregate mixture have dimensions less than 0.063 mm.

The aggregate mixture comprises 0/2 and 2/4 aggregate, preferably the aggregate mixture comprises 10-15% of 0/2 aggregate and 85-90% of 2/4 aggregate,

- the aggregate has an actual density of greater than 2000 kg / m ³ , preferably greater than 2500 kg / m ³ ,

The residual ratio of the hydrocarbon-based binder material is from 4.5 to 6.5%, preferably from 5.4 to 6.2%

Hydrocarbon-based binders are selected from pure bitumen, bitumens modified by polymers such as elastomers of the SBS class, binders of vegetable origin or pure synthetic binders,

- Binders are in the form of anhydrides, fluxes or emulsions.

The remainder of the binder corresponds to the mass of the hydrocarbon-based binder expressed as a percentage based on the total weight of the aggregate and the hydrocarbon-based binder (not including other components of the flux system liquor).

According to the present invention, the foamable organic polymer particles or beads are substantially spherical in shape. Of the polymers suitable for the present invention, mention may be made in particular of styrene-based particles or beads (i.e. polystyrene), styrene / ethylenically unsaturated hydrocarbon copolymers and mixtures thereof. Among the suitable copolymers, mention may be made especially of copolymers obtained from at least one of ethylene, propylene, butylene, butadiene and isoprene monomers and styrene.

In practical terms, the polymeric material may be selected from the group consisting of (i) polystyrene, (ii) styrene / ethylene copolymer, styrene / propylene copolymer, styrene / butylene copolymer , A styrene / butadiene copolymer and a styrene / isoprene copolymer, and (iii) a mixture thereof.

In this range, the polymeric material is advantageously polystyrene or a styrene / ethylene copolymer, a styrene / propylene copolymer, a styrene / butylene copolymer having a styrene / ethylenically unsaturated hydrocarbon moiety molar ratio of 55/45 to 90/100 Copolymers, styrene / butadiene copolymers and styrene / isoprene copolymers.

The particles or beads of this polymeric material generally have an average particle size of 0.1 to 10 mm after swelling.

According to a preferred embodiment, the expandable organic polymer particles or beads comprise " graphite added ", i.e., graphite particles. Methods for making these particles are known and are described in particular in patent US 6,340,713. The particles to which the graphite is added are preferable because the decomposition temperature is higher due to the presence of the graphite. According to the present invention, the " decomposition temperature of the organic polymer particles " means the temperature at which a loss or change of the foaming property is observed. This temperature can be easily measured by simply observing the temperature at which the foamed particle sinks or begins to dissolve in the Kofler test bench.

The graphite-added polymer particles or beads used have a graphite content of 1 to 20% (mass / mass). The content is advantageously from 1 to 5%, more preferably from 2 to 3%.

The coefficient of thermal conductance of the organic polymer particles? (Corresponding to a flux of heat across 1 m ² of a 1 m thick wall when the temperature difference between two faces is 1 °) is preferably less than 0.05 W / mK, preferably 0.04 W / mK.

Examples of the beads to which graphite is not added include those available under the trade name Styrobeton®, and graphite-added beads include those marketed under trade names Activator® or Neopore®.

The composition according to the present invention provides a road top layer that reduces noise and rubber wheel / road contact noise, particularly caused by automobile engines.

Other features, aspects, and advantages of the present invention will become more apparent from the following detailed description, and the teachings of the specific embodiments, which are intended to be illustrative, not limiting.

In the context of this specification, " grading " means the aggregate size distribution of an aggregate mixture, expressed as a percentage of the mass passing through a specimen assembly. By " passing fraction " is meant the fraction of the aggregate mixture that has passed through the smallest sieve used to classify the aggregate. These definitions correspond to the definitions of XP P18-545 and EN 13043 standards.

The passing fraction is obtained by particle size analysis by sieving according to EN 933-1 standard during the measurement of the particle size.

The aggregates represented by d / D and d <D represent the particle size range for the smallest body size (d) expressed in mm and the largest body size (D). The dimensions of the particles, and more typically the dimensions of the constituents of the aggregate mixture, correspond to their diameters when the constituent has a spherical shape. If the component is not spherical, the dimension corresponds to the length of its major axis, i.e. the length of the longest straight line drawn between one end and the opposite end of the component. This can be characterized by sieving. The definition of these particle sizes applies not only to aggregates used according to the invention but also to organic polymer particles.

The composition for a road upper layer according to the present invention comprises an aggregate mixture and at least one binder satisfying the above conditions.

The term " apparent density " means mass per cubic meter of material taken as a dummy including both particle-permeable and impermeable voids and interparticle voids in accordance with the present invention. The material is not compressed.

According to the present invention, the term aggregate refers to an aggregate that meets the requirements for a paint. These aggregates preferably originate from the crushing of large rocks or sedimentary rocks.

The aggregate used in accordance with the present invention can be selected according to the composition of the aggregate. Thus, typical aggregates are aggregate materials used in the construction sector. Aggregates can be natural, artificial or recycled aggregates. &Quot; Natural aggregate " does not undergo any deformation other than mechanical deformation. &Quot; Artificial aggregate " means an aggregate of mineral origin originating from an industrial process including thermal deformation. &Quot; Recycled aggregate " means an aggregate obtained by the treatment of an inorganic material previously used in the field of construction. The aggregate used is road aggregate conforming to the appropriate standard (NF EN 13043 in Europe and ASTM C33 in the United States). The aggregate class (d / D) of the constituents of these packages which are the subject of the French product standard series NF P98-130 to NF P98-141, which can be used according to the invention, are 0/2, 0/4, 2/4 , 0 / 6.3, 2 / 6.3 and 4 / 6.3. These aggregate classes are commonly referred to as the XP P18-540 standard, which is now replaced by the XP P18-545 standard.

Typical aggregates present in the compositions according to the present invention may be, without limitation, fillers, fine aggregates, sand, cement, gravel, fine gravel, stone, crushed stone, stone powder, fillers. The filler means a particle having at least 70% by mass of particles having a dimension of less than 0.063 mm.

The hydrocarbon-based binder utilized in accordance with the present invention assures solidification between them by solidifying the different constituents of the aggregate mixture with each other when used in an upper layer that is partially or wholly covering the constituents. This can be used to adhere the components of the aggregate mixture substantially on a support on which it is distributed. Since the noise preventing characteristics are basically due to the specific composition and particle size of the aggregate mixture, the hydrocarbon-based binder usable in the present invention may have various properties.

According to a first embodiment of the present invention, the binder is a " bituminous binder ", which is called a bitumen bitumen, a modified bitumen or a mixture thereof, and can bind and cure the aggregate materials together. The bituminous binders according to the invention are generally mixtures of natural hydrocarbon materials derived from natural veins present in solid or liquid form, generally having a density of from 0.8 to 1.2, or from heavy fractions obtained upon distillation of petroleum. This can be manufactured by all conventional techniques.

Pure bitumen as defined in standard NF EN 12591, such as, but not limited to bitumen of classes 160/220, 100/150, 70/100, 50/70, 40/60, 35/50, 30/45 or 20/30, It is recognized as a bituminous binder in the context of the invention. These standardized classes correspond to the permeability range expressed at 1/10 mm and at 25 ° C measured according to EN 1426 method.

More advantageously, the bituminous binders can be modified by modified bitumen as defined in the NF 14023 standard, for example in terms of improving mechanical durability or adhesion properties under increased traffic or over traffic, or artificially imparting properties necessary for use as cationic milks Lt; RTI ID = 0.0 &gt; additive &lt; / RTI &gt; (Polybutadiene, styrene-butadiene rubber or SBR), a copolymer of ethylene and vinyl acetate (EVA), a conjugated diene and a copolymer of ethylene and vinyl acetate, by the incorporation of organic or inorganic fibers, in particular glass, carbon or cellulose, By incorporation of a random or block or copolymer of styrene, such as an SBS block copolymer, by the incorporation of thermoplastic materials such as polyolefins (polyethylene, polypropylene), polyamides and polyesters, or by the addition of epoxy resins ) Or an improved bitumen by incorporation of a thermosetting resin such as a polyurethane resin. This list is non-restrictive. Other types of bituminous mixtures can also be used.

According to another embodiment of the present invention, the binding material may be of plant origin. It may be a natural resin or a resin of vegetable origin denatured by synthesis. This binder category is interesting because it comes from renewable agricultural resources. Examples include binders disclosed in patent application FR 2853647, such as Vegecol (R), marketed by Colas.

According to a third embodiment of the present invention, the binder is a pure synthetic binder. Generally, these synthetic binders are organic, preferably polymeric. It can be in the form of a thermoplastic, an elastomer or a thermosetting or reticulated material, or a mixture of one or more of these materials.

Of course, the composition according to the invention may comprise a mixture of binders belonging to different categories mentioned, i. E. It may comprise at least one binder selected from bituminous binders, plant-origin binders and pure synthetic binders.

The binders used in the present invention may comprise one or more coloring agents such as additives such as metal salt type curing catalysts and / or inorganic pigments or organic coloring agents.

The binders given above may be selected from flux or a flux agent for lowering the viscosity, for example a flow agent based on a solvent based on petroleum, petrochemical or coal chemical origin, or a flow based on a fatty material of natural origin Can be further fluidized. These binders may contain substantially 0.5 to 35% by mass, preferably 0.5 to 10% by mass, of a fluidizing agent based on the total mass of the binder. These binders may in particular be in the form of an emulsion or an anhydrous form according to NF EN 13808, or a mixture of the two.

When the binder is used in the form of a liquid, the affinity of the binder to water depends on the interfacial tension between these two products. This affinity may be improved by anionic, cationic, amphoteric or nonionic surfactants such as, for example, hydrochlorides, fatty acid salts of fatty acid amines, quaternary ammonium salts, ethylene polyoxides or mixtures of these compounds.

Preferably, the aggregate mixture and binder (s) are used in an amount such that the composition has a richness ratio of at least 3, preferably from 3.3 to 3.6 as defined in the NF P98-149 standard.

The foamable organic polymer particles have a function of filling voids contained in the package. In order to determine the amount of foamable organic polymer particles to be added, it is convenient to measure the bulk density of the package and the actual density of the packaging according to NF EN 12697-5 by rotating shear press (PCG) test. For this purpose, a test piece comprising an aggregate mixture and a hydrocarbon-based binder (excluding foamable organic polymer particles) is prepared. This test can measure the percentage of geometric voids according to the number of revolutions. There is a correlation between the number of revolutions and the implementation thickness of the package. The contents of voids obtained at 20 and 40 revolutions correspond to the values of packaging realized with thicknesses of 2 cm and 4 cm, respectively.

As a result, packages with a specific void content at 40 revolutions and applied at 4 cm should have theoretically the same void content.

The volume to which the expandable organic polymer particles are added is determined according to the following relationship:

Wherein,

V _ppe : volume (m ³ ) of foamable organic polymer particles per tonne of package,

MVRE: The actual density of the packaging in tonnes per ³ m,

x% in rotation%: Percentage of voids obtained by PCG in x rotation, x is chosen depending on the implementation thickness of the package.

The present invention is also directed to a method for producing a composition for road upper layer according to any one of the above items,

comprising the steps of: a) preparing a test piece from a packaging composition comprising an aggregate mixture and a hydrocarbon-

b) - Percentage of geometric voids by rotational shear press (PCG) test according to NF EN 1269-31 standard for a packaging composition comprising an aggregate mixture and a hydrocarbon based binder,

- actual density according to NF EN 12697-5 standard of the packaging composition comprising the aggregate mixture and the hydrocarbon based binder

, &Lt; / RTI &gt;

c) calculating the volume of the foamable organic polymer particles added to fill all or part of the pores of the packaging mixture, preferably all pores, according to the percentage and the actual density of said geometric pores,

d) mixing the binder or binders, the aggregate mixture and the expandable polymer particles according to the volume determined in step b)

.

The volume of foamable organic polymer particles to fill all the voids of the packaging composition is calculated according to the following relationship:

Wherein,

V _ppe : volume (m ³ ) of foamable organic polymer particles per tonne of package,

MVRE: The actual density of the packaging in tonnes per ³ m,

x% of voids in rotation: Percentage of voids obtained by PCG in x rotation, x is chosen according to the implementation thickness of the package.

The manufacturing method is changed depending on the type of the foamable organic polymer particles to be selected. Indeed, those skilled in the art will choose a modified manufacturing temperature, i.e., a temperature that is preferably below the decomposition or deformation temperature of these particles.

Step d) is carried out at a temperature selected according to the decomposition temperature of the organic polymer particles.

Thus, step d) may be carried out at a temperature of less than 140 ° C, or in the range of 100 to 140 ° C, preferably less than 130 ° C, in accordance with the practice of the present invention. In fact, the organic polymer particles to which graphite has been added are not decomposed at a temperature of 140 DEG C or lower.

According to another embodiment of the present invention, in order to avoid all the risk of decomposition of the expandable organic polymer particles, the composition can be prepared at a temperature of less than 100 ° C. To this end, the hydrocarbon-based binder is an emulsion or a fluid, and step c) is carried out at a temperature below 100 ° C, preferably at ambient temperature.

The expandable organic polymer particles to which graphite is not added generally have a decomposition temperature near 120 ° C. The selection of the binder or the choice of the emulsified form flowing in the bubble form is changed in such a way as to lower the production temperature.

The method preferably comprises packaging all or a portion of the aggregate mixture by means of a binder (or binders). This step may be carried out at high or low temperature according to the NF P98-15 standard for hot or cold packaging. In the manufacture of low temperature packaging, where the binder is in the form of a liquid, the technique has the title of a liquid packaging.

Another object of the present invention is the use of a composition as defined above for the implementation of a road top layer having anti-noise properties. The compositions of the present invention are particularly adapted for use in residential areas where vehicle traffic can cause transitional noise, which can be particularly harmful to a population of people. These repetitive noises can actually have a detrimental effect on sleep and health and can cause physiological problems, especially respiratory, blood pressure, and nervous system effects. The use of the compositions of the present invention provides a road top layer that reduces noise and rubber wheel / road contact noise, particularly caused by automotive engines.

According to the road top layer composition of the present invention, it is possible to manufacture a running layer as specified in the 1994 SETRA / LCPC Roadway Concept and Dimensioning Technical Guide and the hydrocarbon-based NF P98-150 standard.

Here, the running layer means a material layer in direct contact with the rubber wheel of the vehicle in the present invention.

Another object of the present invention is a road upper layer having a noise-preventing property based on at least the composition for a road upper layer as defined above.

The upper layer of the road has a compression thickness of 50 mm or less, preferably 25 to 45 mm, more preferably 30 to 40 mm.

The overall thickness of the road upper layer of the present invention depends on the application type and the sound absorption effect sought. The optimum thickness for maximum absorption of road traffic noise in the upper part of the road which is the object of the present invention is 25 to 45 mm spacing, more advantageously 30 to 40 mm spacing, the tolerance is preferably -1 cm at the lower limit It is +1 cm at the upper limit.

The road top layer of the present invention can be applied on a new or old support consisting of a material that is combined with a hydrocarbon-based or hydraulic binder. This layer has a noise characteristic that significantly reduces the noise emissions caused by the rubber wheel / road contact upon passage of the vehicle.

The specific particle size of the composition of the invention leads to a road top layer having a void fraction of preferably 20% or more, in the sense of the EN 12697-8 standard, for a coating thickness as described above. The road top layer of the present invention preferably has a void fraction of preferably 25 to 30% or greater in the sense of the N 12697-8 standard.

The above road surface layer defined above can be prepared using a composition according to the present invention, which is produced according to the packaging technique, i.e., by contacting the aggregate mixture with the binder before application onto the support. The support to which the layer of the present invention is applied may be through a substantially known manufacturing step.

Other features and advantages of the present invention will become apparent from the following description of exemplary embodiments.

I. Materials Used

1. Aggregates and organic polymer particles

2. Hydrocarbon system Binders

The hydrocarbon-based binder used is Bitulastic® EB or EC, a modified bitumen corresponding to a mixture of thermoplastic elastomer of the polystyrene-polybutadiene-polystyrene type and road bitumen mixture with 0.4% amine-type liquid additive capable of lowering the packaging production temperature . Its actual density is 1030 kg / m ^3, measured according to the NF EN 15326 standard.

II . Manufacturing and Characteristics of Packaging

1. Composition and size distribution of pavement

Table 1 shows the composition and the particle size distribution of the aggregate mixture for each test composition.

In order to prepare the composition for road upper layer according to the present invention, a test piece is prepared from a packaging composition comprising a hydrocarbon-based binder and an aggregate mixture. Such a test piece corresponds to, for example, a comparative composition. The percentage of geometric voids and the actual density of the packaging composition were measured by a rotating shear press (PCG) test according to the NF EN 1269-31 standard. At 40 turns, a void fraction of 26.4% was obtained and the actual density of this packaging composition is 2.507 t / m ³ . A package made from this composition to be implemented to a thickness of 4 cm will have a void content of 26.4%.

Thus, the volume (V _ppe ) of the expandable organic polymer particles added per tonne of the packaging composition to fill the total pores of the packaging composition is: V _ppe = (1 / 2.507) x (26.4 / 100) = 0.105 m ³ .

* Mass% relative to the total mass of the packaging composition.

2. Manufacturing method and characteristics

The package is manufactured in accordance with NF EN 12697-35 standard in a kneader for 240 seconds at a temperature of 125-160 ° C (see Table 2). Table 2 shows the characteristics of the different packaging tested.

The conditions of the PCG test are as follows:

To evaluate the sound absorption performance of the composition, a package is prepared in accordance with NF EN 12697-35 standard in a kneader. The resulting specimens are compressed with Gyropac until the desired compaction is achieved, that is, the compaction is measured as measured in the PCG test. Sound absorption characteristics were realized by the impedance tube. The test principle is the subject of NF EN 10534-1 and 2 standards. The casting diameter of the specimen corresponds to the diameter of the impedance tube.

NOTE: The void content corresponds to the value measured in Gyropac during compression of the specimen. We want to reach the desired compaction which is as close as possible to the value measured in the PCG. In the packaging composition of the present invention, graphite-added expandable polystyrene (PSE) fills the voids. Thus, the measurement of void content corresponds to the PSE content filling the void. To carry out this measurement, equate the PSE with the void. In practice, the density of PSE is negligible compared to aggregate, and the measurement error is not large.

conclusion:

The embodiments have acoustic properties of the same formulation with / without polystyrene beads, at different compaction densities. According to the packaging composition according to the present invention, at least the same acoustic characteristics can be obtained and sustained.

Claims (12)

A bituminous packaging composition comprising an aggregate mixture and at least one hydrocarbon-based binder,
a) the aggregate mixture satisfies the following conditions:
- 10 to 25 mass% of the constituents of the aggregate mixture are aggregates having a particle size range of 0 to 2 mm,
- 70 to 95 mass% of the constituents of the aggregate mixture are aggregates having a particle size range of 2 mm or more and 4 mm or less and / or 4 mm or more and 6 mm or less,
b) the composition further comprises from 0.1 to 1% by weight, based on the total weight of the bituminous packaging composition, of the foamable organic polymer particles. The bituminous packaging composition of claim 1, wherein the foamable organic polymer particles comprise graphite microparticles. The bituminous packaging composition according to claim 1, wherein the foamable organic polymer particles have an apparent density of 15 to 50 kg / m ³ . The bituminous packaging composition according to claim 1, wherein the foamable organic polymer particles have a particle size of 1 to 4 mm. The bituminous packaging composition according to claim 1, wherein the foamable organic polymer particles are 0.1 to 0.5 mass% based on the total mass of the packaging composition. The method according to claim 1,
The aggregate mixture
- 10 to 15 mass% of aggregates having a particle size range of more than 0 and less than 2 mm and
- Aggregate having a particle size range of 2 mm or more and 4 mm or less 85 to 90 mass%
Lt; RTI ID = 0.0 &gt; 1, &lt; / RTI &gt; A process for preparing a bituminous packaging composition according to any one of claims 1 to 6,
comprising the steps of: a) preparing a test piece from a packaging composition comprising an aggregate mixture and a hydrocarbon-
b) - Percentage of geometric voids by rotational shear press (PCG) test according to NF EN 1269-31 standard for a packaging composition comprising an aggregate mixture and a hydrocarbon based binder,
- actual density according to NF EN 12697-5 standard of the packaging composition comprising the aggregate mixture and the hydrocarbon based binder
, &Lt; / RTI &gt;
c) calculating the volume of foamable organic polymer particles added to fill all or part of the pores of the packaging mixture according to the percent and actual density of said geometric voids,
d) mixing the binder or binders, the aggregate mixture and the expandable polymer particles according to the volume determined in step b)
&Lt; / RTI &gt; 7. A bituminous packaging composition according to any one of claims 1 to 6, wherein the bituminous packaging composition is for the implementation of a road top layer having an anti-noise characteristic. A road top layer having an anti-noise characteristic based on at least one composition according to any one of claims 1 to 6. The road top layer of claim 9, wherein the compression thickness is 50 mm or less. The road top layer of claim 9, wherein the compression thickness is 25 to 45 mm. The road top layer of claim 9, wherein the compression thickness is 30 to 40 mm.