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
  • E01C19/02—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 the materials
  • E01C19/10—Apparatus or plants for premixing or precoating aggregate or fillers with non-hydraulic binders, e.g. with bitumen, with resins, i.e. producing mixtures or coating aggregates otherwise than by penetrating or surface dressing; Apparatus for premixing non-hydraulic mixtures prior to placing or for reconditioning salvaged non-hydraulic compositions
  • E01C19/1059—Controlling the operations; Devices solely for supplying or proportioning the ingredients
  • E01C19/1068—Supplying or proportioning the ingredients
  • E01C19/1072—Supplying or proportioning the ingredients the solid ingredients
• • 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
  • E01C19/02—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 the materials
  • E01C19/10—Apparatus or plants for premixing or precoating aggregate or fillers with non-hydraulic binders, e.g. with bitumen, with resins, i.e. producing mixtures or coating aggregates otherwise than by penetrating or surface dressing; Apparatus for premixing non-hydraulic mixtures prior to placing or for reconditioning salvaged non-hydraulic compositions
  • E01C19/1004—Reconditioning or reprocessing bituminous mixtures, e.g. salvaged paving, fresh patching mixtures grown unserviceable; Recycling salvaged bituminous mixtures; Apparatus for the in-plant recycling thereof
• • 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
  • E01C19/02—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 the materials
  • E01C19/10—Apparatus or plants for premixing or precoating aggregate or fillers with non-hydraulic binders, e.g. with bitumen, with resins, i.e. producing mixtures or coating aggregates otherwise than by penetrating or surface dressing; Apparatus for premixing non-hydraulic mixtures prior to placing or for reconditioning salvaged non-hydraulic compositions
  • E01C2019/1081—Details not otherwise provided for
  • E01C2019/1095—Mixing containers having a parallel flow drum, i.e. the flow of material is parallel to the gas flow

Definitions

• the invention relates to a process for producing a bituminous mix comprising inorganic solid fractions coated with a binder, the process comprising a step of heating a part of said mineral solid fractions and then a step of simultaneous introduction of the binder and of the part remaining of said mineral solid fractions.
• Mineral solid fractions here means all solid fractions that can be used for the production of bituminous mixes, in particular for road construction, including in particular natural mineral aggregates (chippings, sand, fines), and asphalt aggregates resulting from recycling. materials recovered during road repairs and surplus asphalt plants.
• Asphalt aggregates means asphalt mixes (mixture of aggregates and bituminous binders) from milling asphalt layers, crushing plates extracted from asphalt pavements, pieces of asphalt mix coated or surplus production of asphalt (surplus production are coated or partially coated in the plant resulting from the transitional phases of manufacture
• the mineral solid fractions may be chosen from elements less than 0.063 mm (filler or fines), sand whose elements are smaller than 2 mm, gravel, whose elements have dimensions greater than 2 mm, and aggregates originating from recycled materials, the elements of which can reach dimensions up to 31.5 mm.
• binder any hydrocarbon binder of fossil or plant origin used for the production of asphalt, including bitumen pure or added fluxers and / or fluidizers and / or regenerants and / or pigments and / or modified by adding polymers.
• This binder can also be doped by adding tackifiers (fatty amine derivatives, such as Polyram L 200 supplied by the company CECA, or alkymamido-imidazo polyamines).
• This binder can be introduced as is or be modified to be in the form of an emulsion, a dispersion or a bitumen foam.
• Bitumen foam means an injection process in the arrival of the binder of a quantity of water and possibly air, the water being pure or additive additives to modify the properties of adhesiveness or rheological of the binder.
• the mineral solid fractions are dried, before the coating step, so as to remove moisture from the mineral solid fractions, which requires a considerable energy expenditure because of the large amount of water initially contained in these fractions, especially sand and aggregates.
• drying and raising of temperature result in the release of fumes containing dust-laden water vapor.
• EP 1 469 038 A proposes to bring the drying step on a first portion of the mineral solid fractions, substantially free of fines, to coat hot bitumen this first part, and then adding to the mixture thus obtained a second portion of the mineral solid fractions, including sands and fines.
• This process requires the provision of two mineral solid fractions, one free of fines and the other containing fines, which may involve difficulties.
• this process can not be effectively implemented in some existing coating plants, and may therefore require an expensive arrangement thereof.
• FR 2 884 265 proposes an equivalent process in which the first part of the mineral solid fractions may contain fines.
• FR 2 884 264 proposes a process in which all the mineral solid fractions (aggregates, sands and fines) are subjected to a drying process that leaves a fraction of the initial moisture and then remains coated.
• the object of the invention is to eliminate all or part of these disadvantages.
• step a2 means that said first heated subdivision is, at the beginning of step a2), at a temperature such that the assembly resulting from mixing said first subdivision with said second subdivision is at a temperature greater than 80 ° C, preferably greater than 100 ° C.
• said second subdivision does not need to be heated beforehand.
• the solid mineral fractions introduced in steps a) and b) advantageously both comprise fines, sand and chippings (as defined above). They may further comprise asphalt aggregates (as defined above).
• the solid mineral fractions introduced in step b) advantageously comprise sand whose elements are less than 2 mm, chippings, the elements of which have dimensions greater than 2 mm and possibly aggregates originating from recycled materials, whose elements can reach dimensions up to 31.5 mm.
• step b) the solid mineral fractions introduced in step b) are advantageously used in cold (that is to say at room temperature), in particular they have not been previously heated. Aggregates from recycled materials that can be introduced in this step b) are advantageously used cold, they have not been previously heated.
• not previously heated means that the solid mineral fraction is introduced cold (ie at room temperature) and that it was not, at any time during the process, dried by heating.
• step b) the binder and said remaining portion of the solid fractions are introduced separately but simultaneously into said first portion of the solid mineral fractions.
• the binder and said remaining portion of the solid fractions have not been previously mixed.
• the end times for introducing the binder and said remaining portion of the solid fractions may coincide or diverge.
• all of said remaining portion of the solid mineral fractions is introduced simultaneously to the binder so that all of said remaining portion of the solid mineral fractions is introduced while only a portion of the binder has been introduced ( or the entire binder and then the insertion end times coincide).
• the entire binder is introduced simultaneously with the introduction of said remaining portion of said solid mineral fractions so that all the binder is introduced at the same time as only a part of said remaining portion of the solid fractions is introduced (or all and then the insertion end times coincide).
• the process allows the recovery of asphalt aggregates resulting from the recycling of materials recovered during the repair of roads (and others).
• the inventors have found that even better results are obtained when using regenerated asphalt aggregates; that is to say aggregates of mixes having been brought into contact with a regenerating agent.
• the aim is to regenerate the old binder, whose hardening comes from the physico-chemical transformation of some of its constituents, by corrections of its consistency and its chemical constitution by means of a suitable agent, which must be a solvent of binder.
• This regenerating agent has a fluidifying and repeptising power (dispersion of asphaltenes) on the old binder sufficient to reconstitute, with said old binder, a binder having the desired properties (mechanical and rheological properties).
• the use of such a regenerating agent makes it possible to improve the migration of the old binder (present in the asphalt aggregates) towards the new mineral solid fractions, so as to be equally distributed over all the mineral solid fractions.
• the regenerating agent can be of petroleum, coal, vegetable, mineral or combined origin of the different products. These include vegetable oils, mineral oils (paraffin), aromatic oils and recycling binders having an aromatic character with low levels of asphaltenes. These last two families are notably marketed by TOTAL in the Regenis ® product range.
• the amount of regenerating agent will be between 1 and 50% relative to the binder content in the aggregate asphalt and preferably between 10 and 30%.
• the asphalt aggregates represent between 5% and 70% and preferably 20 to 40% of the mass of the weight of the mineral solid fractions constituting said first part.
• the grade of the bitumen and its quantity will be defined according to the percentage of regenerating agent, the bitumen present in the asphalt aggregates and the expected specifications for the asphalt mix.
• the remaining part, introduced in step b), advantageously represents from 5 to 50%, more advantageously 10 to 50%, still more advantageously 20 to 40%, of the mass of the weight of said fractions. solid minerals.
• a controlled quantity of water is added.
• This water may be added during step b) of simultaneous introduction of the binder and of said remaining part. It can also be added after step b). It can finally be added to said remaining portion of solid mineral fractions prior to step b). Water can be added to only one or more of these stages.
• the binder is advantageously used at a temperature between 100 and 200 ° C, preferably about 160 ° C.
• the binder emulsion is advantageously used at a temperature of between 10 and 95 ° C.
• step b the addition of an undried solid mineral fraction (step b) at room temperature has the effect of reducing the outlet temperature of the mixes.
• this method makes it possible to reduce the cycle times and thus to increase the production capacities of the batch type production facilities and to reduce the lengths of the mixers of the continuous type installations. , with equivalent coating quality.
• the method according to the invention is implemented in discontinuous power plants. In another embodiment, it is implemented in continuous power plants, advantageously those with a parallel-current coater-drying drum, with a single-envelope countercurrent-coating drum dryer. and drum dryer with separate parallel shaft type mixer or drum mixer type.
• the binder is a 35/50 or 20/30 penetrability bitumen according to the NF EN 1426 standard. The percentages are given in mass relative to the total mass of the bituminous mixes.
• Examples 1 to 3 are made in laboratories. Examples 4 to 6 were made on a construction site.
• Example 1 BBSG 0/10 Diorite
• the binder is a 35/50 penetration bitumen: 5.4%. 65% of the aggregates (11% 0/2, 19% 2/6 and 35% 6/10) are heated to 140 ° C and then mixed using a kneader. Then, the addition of the fraction 0/2 having a moisture of 3% and the bitumen (heated to 160 ° C) simultaneously are introduced into the kneader (containing the heated fraction).
• the mix is mixed and the final temperature is 98 ° C.
• Example 2 BBSG 0/10 Diorite + asphalt aggregates
• the binder is a 35/50 penetrability bitumen: 4.1% (ie total bitumen: 5.4%)
• Asphalt aggregates and 2/6 and 6/10 aggregates are heated to 140 ° C. Then, the 0/2 fraction having a humidity of 4% and the bitumen (heated to 160 ° C.) are introduced simultaneously into the mixer (containing the heated fraction).
• the mix is mixed and the final temperature is 100 ° C.
• NF EN 13108-1 THIS C II C III DURIEZ test NFP 98-251-1 % empty average R18 (MPa) r18 (MPa) r / R 8 13.2 10.5 0.80 > 0.75 rutting NF EN 12697-22 empty% rut to 30000% cycles 7.9 4.1 ⁇ 10 5-8 ⁇ 7.5 ⁇ 5 PCG NF EN 12697-32 % empty 60 girations 8.7 5-10 Module according to NF EN 12697-26 Average modulus in direct traction (15 ° C-0.02s in MPa) % empty average 12930 7.2 > 5500 > 7000 > 7000 5-8 Fatigue resistance according to NF EN 12697-24 ⁇ 6 at 10 ° C -25Hz ( ⁇ def) % empty medium fatigue 102 7.9 > 100 5-8
• Example 3 BBSG 0/10 Diorite + asphalt aggregates, 20/30 bitumen + regenerant
• the binder is a 20/30 penetrability bitumen: 3.8% and a regenerant is introduced (0.3%) (ie total bitumen: 5.3%)
• the asphalt aggregates and 2/6 and 6/10 aggregates are heated to 150 ° C.
• the aggregates heated with the regenerant at 150 ° are mixed using a mixer with two parallel shafts. Then, introduced into the mixer (containing the heated fraction) fraction 0/2 comprising 4% humidity and bitumen (heated to 170 ° C) simultaneously.
• the mix is mixed and the final temperature is 105 ° C.
• Example 5 BBSG 0/10
• An energy-efficient bituminous mix is obtained at a temperature of 98 ° C., with a manufacturing cycle time of 45 seconds (identical to that of an equivalent hot mix).
• the voids content and the modulus on cores taken from the building site after 7 days comply with standard NF EN 13108-1.
• An energy-efficient bituminous mix is obtained at a temperature of 95 ° C., with a manufacturing cycle time of 45 seconds (identical to that of an equivalent hot mix).
• the voids content and the modulus on cores taken from the building site after 7 days comply with standard NF EN 13108-1.

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• Engineering & Computer Science (AREA)
• Architecture (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Road Paving Structures (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Processes Of Treating Macromolecular Substances (AREA)

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Citations (10)

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• 2008
  • 2008-02-01 FR FR0850643A patent/FR2927094B1/fr not_active Expired - Fee Related
• 2009
  • 2009-02-02 CA CA002653562A patent/CA2653562A1/fr not_active Abandoned
  • 2009-02-02 EP EP09151857A patent/EP2085518A1/de not_active Withdrawn
  • 2009-02-02 US US12/320,708 patent/US20090208655A1/en not_active Abandoned

Patent Citations (10)

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