Classifications

• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01C—CONSTRUCTION OF, OR SURFACES FOR, ROADS, SPORTS GROUNDS, OR THE LIKE; MACHINES OR AUXILIARY TOOLS FOR CONSTRUCTION OR REPAIR
  • E01C19/00—Machines, tools or auxiliary devices for preparing or distributing paving materials, for working the placed materials, or for forming, consolidating, or finishing the paving
  • E01C19/48—Machines, tools or auxiliary devices for preparing or distributing paving materials, for working the placed materials, or for forming, consolidating, or finishing the paving for laying-down the materials and consolidating them, or finishing the surface, e.g. slip forms therefor, forming kerbs or gutters in a continuous operation in situ
• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01C—CONSTRUCTION OF, OR SURFACES FOR, ROADS, SPORTS GROUNDS, OR THE LIKE; MACHINES OR AUXILIARY TOOLS FOR CONSTRUCTION OR REPAIR
  • E01C19/00—Machines, tools or auxiliary devices for preparing or distributing paving materials, for working the placed materials, or for forming, consolidating, or finishing the paving
  • E01C19/46—Machines, tools or auxiliary devices for preparing or distributing paving materials, for working the placed materials, or for forming, consolidating, or finishing the paving for preparing and placing the materials, e.g. slurry seals
• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01C—CONSTRUCTION OF, OR SURFACES FOR, ROADS, SPORTS GROUNDS, OR THE LIKE; MACHINES OR AUXILIARY TOOLS FOR CONSTRUCTION OR REPAIR
  • E01C7/00—Coherent pavings made in situ
  • E01C7/08—Coherent pavings made in situ made of road-metal and binders
  • E01C7/18—Coherent pavings made in situ made of road-metal and binders of road-metal and bituminous binders

Definitions

• the invention relates to a method for manufacturing a cold bituminous mix for road surfaces, as well as to a device for manufacturing a cold bituminous mix for road surfaces.
• Bituminous mixes are generally obtained by hot manufacturing (so-called “hot” mixes) or by cold manufacture (so-called “cold mixes”). Hot manufacturing consists of drying and heating aggregates to a temperature above 100 ° C, and kneading them with an anhydrous hydrocarbon binder, fluid and not very viscous at this temperature.
• the hot manufacturing generally allows: - a good coating of all the fractions by dispersion of the binder in an intimate and homogeneous way, - an implementation at a sufficient temperature so that the spread and compacted asphalt reaches a level of compactness and characteristics aimed flatness in accordance with the rules usually used by those skilled in the art, - an increase in the mechanical resistance of the mix during cooling to achieve the necessary cohesion allowing the circulation of the roadway.
• hot mixes are subject to increasing constraints related to the cost of fuels necessary for the rise in temperature, the sophistication of manufacturing plants and the increasingly strict framework of environmental laws. Hot mixes do not allow the use of bitumen emulsi, force materials to dry, require hot installations and cause the release of smoke and dust during manufacture.
• Cold manufacturing consists in kneading aggregates, possibly moistened, with an emulsion-based hydrocarbon binder, which makes it not very viscous, at a temperature close to ambient temperature, that is to say generally at a temperature of 10 at 20 ° C, on average close to 15 ° C.
• the aggregates can be pre-coated, before coating with the hydrocarbon binder in emulsion.
• double coated cold mix we speak of double coated cold mix. Cold manufacturing allows the coated materials to be used at the manufacturing temperature close to room temperature, the coated material having a workability which depends on the ambient temperature, the choice of binder, the coalescence of the emulsion, the water content and reactivity of the aggregates with respect to the chemical nature of the binder.
• Cold mixes overcome many of the constraints associated with hot mixes, but nevertheless have defects: on the one hand, the coating can be of poor quality, and on the other hand, the workability can be poor, which which can have consequences on the performance of the structure produced, in terms of elasticity, resistance to fatigue, resistance and cohesion of the surface (poor geometric quality of the surface).
• the patent FR-2732239 generally describes a process which, starting from any cold mix, based on viscous bitumen, makes it possible, by non-drying heating, to open a hot mix and its installation in the vicinity of 100 ° C.
• bituminous emulsions must be obtained in the mixers, that is to say, before the heating, the bituminous coating emulsion has undergone a change of state important and therefore of rheology.
• reheating to a temperature of about 100 ° C, a relatively very high temperature will further significantly modify the rheology of the mix during laying.
• the use of a drying drum of a hot coating station does not make it possible to obtain a controlled warming at a temperature of 30 to 65 ° C.
• the aim of the present invention is therefore to remedy the above problems, and to propose a method for manufacturing a cold bituminous mix which makes it possible: - to control the coalescence of the emulsion of the bituminous binder; - to reduce the grade of the bituminous binder; - Improving the workability of the mix by reducing the viscosity of the bituminous binder and therefore increasing the compactness in place after implementation and compaction; to improve the cohesion and the speed of setting of cohesion of the mix in order to obtain an accelerated hardening of the surface, thus limiting the problems of sensitivity of surface resistance known in cold mixes of the prior art, and interfering with their development (for example, brands of tires for agricultural machinery during the first days of operation of the roadway); - to improve the quality of the coating of aggregates, which is decisive for the good resistance of the mix to the action of water, as well as to surface attack, plumage and mittage; - reduce the residual water content of the mix to increase the rate of ripening
• the invention therefore relates to a process for the manufacture of a cold bituminous mix for road surfaces, obtained by coating aggregates with a bituminous binder in emulsion, the aggregates possibly being pre-coated with a hydrocarbon binder, said process comprising, after coating , and preferably without the bituminous binder emulsion having broken beforehand, one or more steps in heating the mix to obtain a temperature of the mix, at the time of its implementation, of 30 at 65 ° C.
• the bituminous binder in coating emulsion is a cationic bitumen emulsion.
• the aggregates can be pretreated with a hydrocarbon binder, before coating with the binder bituminous emulsion.
• This pre-coating can be carried out either hot, for example with an anhydrous hydrocarbon binder, or cold, with a bituminous emulsion binder.
• binders which can be used for pre-coating mention may be made of cationic bitumen emulsions and pure bitumens conventionally used as mixes for wearing courses.
• This double coating allows a complete coating of all the aggregates. There is thus a reduction in the risks of segregation and an increase in the mechanical performance of the mix.
• cold mix having been formulated by pre-coating and then coating mention may be made of COMPOMAC M2 marketed in addition by the company SCREG OUEST.
• the temperature can be chosen in particular according to the nature of the binder, the water content of the mix and the weather conditions during the use of the mix. Generally, the temperature is raised so as to obtain a temperature at the time of processing from 30 to 65 ° C, preferably from 30 to 60 ° C, better from 40 to 60 ° C, and better still from 50 to 55 ° C, typically an increase from 15 to 40 ° C for an ambient temperature of 15 ° C.
• processing temperature is meant the temperature of the mix during the epa ⁇ dage or compaction.
• the choice of temperature rise is also made, possibly taking transport into account, so that the asphalt has the temperature required for its implementation. In all cases, care must be taken not to cause the vaporization of the water included in the mix.
• bituminous coating emulsion according to the invention does not undergo any significant change of state and therefore of rheology before its implementation.
• the process according to the invention can be used to manufacture all types of cold bituminous mixes.
• the bituminous binder can be natural or synthetic.
• the binder is generally a hydrocarbon binder chosen from road bitumens, pure bitumens, fluxed or fluidized bitumens, bitumens modified by polymers, semi-blown bitumens, bitumens partially modified by blown bitumen, and all combinations of these bitumens. Concrete modified by polymers are defined by the standard
• styrene-butadiene copolymers examples include styrene-butadiene copolymers, styrene-isoprene copolymers, ethylene-vinyl acetate copolymers (EVA), terpolymers, such as for example the compound of an ethylenic chain with functional groups of butyl acrylate and methyl glycidyl acrylate which provides good stability to the bitumen / polymer mixture, the elastomers and plastomers allowing a significant improvement in the resistances to cracking and to homerage.
• EVA ethylene-vinyl acetate copolymers
• the aggregates generally have a particle size chosen from the range 0 / D ma ⁇ , D ma ⁇ being the maximum diameter of the aggregate as defined according to standard XP P 18-540 and generally ranging from 4 to 31.5 mm.
• the aggregates used in the process according to the invention can be all types of aggregates usually used for the manufacture of bituminous mixes, for example natural or synthetic materials such as slag, slag, bottom ash, mixtures of mixtures, and mixtures of these materials in all proportions.
• asphalt aggregates are recycling materials originating in particular from the milling of old bituminous coatings.
• the warm bituminous asphalt mix according to the invention comprises from 5 to 12%, preferably from 7 to 10% by weight of binder relative to the weight of the aggregates.
• the warm cold bituminous mix obtained by the process according to the invention can be opened (percentage of vacuum greater than 15% in volume), semi-dense (percentage of vacuum between 10 and 15% by volume) or dense (percentage of vacuum less than 10% by volume). This is obtained by varying in the final mixture the proportion of aggregates 0 / d, where 1 ⁇ d ⁇ x, where x can be equal to 2 mm, 4 mm or 6.3 mm.
• the warm cold bituminous mix obtained by the process according to the invention can also be storable or non-storable.
• the warm cold bituminous mix obtained by the process according to the invention can be, for example, a grave-emulsion, a bituminous concrete with an emulsion or a serious cold bitumen.
• the method according to the invention comprises, after coating, one or more steps of raising the temperature of the mix by heating the mix to a temperature from 30 ° C to 65 ° C.
• the asphalt obtained is possibly stored, then transported to the site of the site, if the coating has not been carried out on the site, to be implemented.
• the asphalt mix is generally implemented by a spreading step on the road and a compacting step.
• the cold mix is heated before spreading, that is to say after the coating and before or after transport to the place of application, if necessary, whether or not there is a storage phase, and / or during spreading and / or after spreading during compaction.
• the flow of asphalt is generally between 50 and 250 tonnes / hour.
• Heating leads to an increase in the temperature of the binder and of the water present in the mix.
• the increase in the temperature of the binder will considerably modify its viscosity and therefore influence the quality of the coating and the workability of the mix.
• the heating is carried out by one or more heating means chosen from infra-red radiation, ultra-violet radiation, microwave waves, high frequency waves and bringing the mix into contact with hot air.
• the invention also relates to a process for manufacturing road surfaces with a cold bituminous mix obtained by coating aggregates with a bituminous binder in emulsion, the aggregates possibly being pre-coated with a hydrocarbon binder, said process comprising one or more stages of increase in the asphalt temperature as defined above.
• the invention relates to a device for manufacturing a cold bituminous mix for road surfaces, obtained by coating aggregates with a bituminous binder in emulsion, the aggregates possibly being pre-coated with a hydrocarbon binder, said device comprising: - a hopper containing the aggregates before coating, - a mixer, on site or in a fixed position, allowing the coating of the aggregates with the binder, - an application table allowing the application of the mix on the pavement, - transfer elements from the mix to the application table, said device further comprising one or more means for raising the temperature of the mix to a temperature from 30 ° C. to 65 ° C.
• the position of the means or means for raising the temperature of the aggregates and of the binder depends on the point or times at which this temperature rise takes place during the implementation of the cold bituminous mix.
• a means for raising the temperature of the mix is positioned at the level of the mixer, the heating being of course carried out after the cold mix has been produced.
• a means for raising the temperature of the mix is positioned after the mixer.
• a means for raising the temperature of the mix is positioned at the level of the transfer elements of the mix.
• the device according to the invention comprises a means for spreading the mix and a means for compacting the mix, a means for raising the temperature of the mix being positioned at the level of the means. for compacting the mix or between the spreading means and the compacting means.
• a heating device suitable for implementing the method of the invention is an aggregate heating tube.
• the invention is illustrated by the following example.
• the aggregates used are ROL and POMPIER aggregates, the particle size of which is as follows: - class 0/4: 50% by weight - class 4/6: 10% by weight - class 6/10: 40% by weight
• Bituminous binder represents 8% by weight of the weight of the asphalt.
• the binder contains: - 65% by weight of bitumen ESSO PJ 70/100 (i.e. a bitumen content in the mix of 5.2% by weight) - 8 kg / tonne of Polyram S - 8 kg / T of acid hydrochloric
• the coating of the aggregates with the bituminous binder is carried out cold in a mixer.
• the initial water content in the coated materials obtained is 6% by weight.
• the coated materials are brought to a temperature of 15 ° C (no temperature raising step according to the invention), 30 C C (the temperature was raised according to the invention) or possibly 50 ° C (the temperature was raised according to the invention).
• Asphalt mixes are subjected to density and odor resistance measures.
• the density is measured using a gyratory shear press.
• the percentage of vacuum is measured at 10, 60 or 200 gir. according to standard NF P 98-252. The results are given in Table 2.
• the homogeneity test is carried out according to standard NF P 95-253-2.

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• Engineering & Computer Science (AREA)
• Architecture (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Road Paving Structures (AREA)
• Working-Up Tar And Pitch (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Road Paving Machines (AREA)

Applications Claiming Priority (2)

Publications (2)

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Cited By (7)

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• 2003
  • 2003-09-19 FR FR0350579A patent/FR2860011B1/fr not_active Expired - Lifetime
• 2004
  • 2004-09-17 WO PCT/FR2004/050444 patent/WO2005028756A2/fr not_active Ceased
  • 2004-09-17 AT AT04816200T patent/ATE524613T1/de not_active IP Right Cessation
  • 2004-09-17 EP EP04816200A patent/EP1668184B1/de not_active Expired - Lifetime

Non-Patent Citations (1)

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